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Wyszukujesz frazę "reaction" wg kryterium: Temat


Tytuł:
Decomposition Pathways for Aqueous Hydroxylammonium Nitrate Solutions: a DFT Study
Autorzy:
Izato, Y.
Koshi, M.
Miyake, A.
Powiązania:
https://bibliotekanauki.pl/articles/357968.pdf
Data publikacji:
2017
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
hydroxylamine nitrate
reaction pathway
liquid-phase reaction
density functional theory
Opis:
Hydroxylammmonium nitrate (hydroxylamine nitrate, HAN) is one of the most promising candidates as a replacement for commonly used liquid mono-propellants such as hydrazine. The reaction pathways involved in the initial and the catalytic decomposition of HAN in aqueous solution were determined using quantum chemistry calculations incorporating solvent effects. Optimized structures were obtained for the reactants, products and transition states at the ωB97XD/6-311++G(d,p)/SCRF = (solvent = water) level of theory and the total electron energies of these structures were calculated at the CBS-QB3 level of theory. In the initial decomposition, the ion-neutral NH3OH+-HNO3 reaction, the neutral-neutral NH3O-HNO3 reaction and the HNO3 self-decomposition pathways were all found to have reasonable energy barriers, with values of 91.7 kJ/mol, 88.7 kJ/mol and 89.8 kJ/mol, respectively. The overall reaction resulting from any of these pathways can be written as: HAN → HONO + HNO + H2O. The ionic reaction is dominant during the initial decomposition of HAN in aqueous solution because NH3OH+ and NO3– are the major species in such solutions. We also developed six catalytic mechanisms and each of these schemes provided the same global reaction: NH2OH + HONO → N2O + 2H2O. The t-ONONO2 oxidizing scheme is the most plausible based on the energy barrier results.
Źródło:
Central European Journal of Energetic Materials; 2017, 14, 4; 888-916
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A meta-analysis of influence of yoga activities on reaction time as a component of skill related fitness
Autorzy:
Ghuntla, Tejas P.
Dholakiya, Jyoti R.
Powiązania:
https://bibliotekanauki.pl/articles/26917700.pdf
Data publikacji:
2023
Wydawca:
Akademia Tarnowska
Tematy:
yoga activities
auditory reaction time
visual reaction time
fitness
effect
Opis:
Introduction: Yoga practices are known to have beneficial effect on cognitive functions. Reaction is a purposeful voluntary response to external stimuli. Reaction time is a component of skill related fitness. Humans gives response to different external environmental stimuli with different speed. Majority of daily work is done in response to visual and auditory stimuli. Yoga practices may improve reaction time. Objectives: To study influence of yoga practices on auditory reaction time and visual reaction time. Methods: Researchers used the Preferred Reporting Items for Systematic Reviews and Meta- Analyses (PRISMA) guidelines for reporting systematic reviews and meta-analysis. Researchers searched articles on PubMed, Google scholar and by manual search. Searched articles were screened for relevancy. By use of inclusion and exclusion criteria potential articles were selected. Results: Out of 287articles, finally 5 studies included in current meta-analysis. Yoga activities has effect on visual reaction time (VRT): SMD = 3.06, 95% CI = –0.66–6.78, P < 0.01 and auditory reaction time (ART): SMD = 2.86, 95% CI = –0.37–6.09. Conclusion: Yogic activities can provide beneficial effect on reaction time. Improved reaction time is important for reactive activity like sports. Yoga can be useful as a part of training in skill related work. There is wide scope for further studies to evaluate beneficial effects of yoga activities.
Źródło:
Health Promotion & Physical Activity; 2023, 24, 3; 50-55
2544-9117
Pojawia się w:
Health Promotion & Physical Activity
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Detonation Reaction Characteristics for CL-20 and CL-20-based Aluminized Mixed Explosives
Autorzy:
Liu, D.
Chen, L.
Wang, C.
Wu, J.
Powiązania:
https://bibliotekanauki.pl/articles/358308.pdf
Data publikacji:
2017
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
detonation reaction zone
aluminum reaction
interfacial particle velocity
interferometry
Opis:
The interfacial particle velocities for CL-20 and CL-20-based aluminized mixed explosives were measured by interferometry in order to analyze the aluminum reactions in the latter. The reaction characteristics were obtained, as well as a better understanding of the effects of aluminum powder on the detonation reaction zone length. Two functions were used to fit the particle velocity-time profiles, and their intersection was the corresponding Chapman-Jouget (CJ) point. From these profiles, the detonation reaction zone length and the aluminum reaction were then analyzed. CL-20-based explosives have a short reaction time (48 ns for a high CL-20 content), while the reaction time of CL-20/Al explosives increased with the aluminum content and particle size. Micron-scale aluminum particles barely reacted in the CL-20 detonation reaction zone, but instead reacted with the detonation products after the CJ point. This reduced the detonation pressure; however, the aluminum reaction can slow down the decrease in particle velocities. The start times of small-particle aluminum reactions were earlier than those of the larger particles. The 2-3-μm aluminum particles start to react within 1 μs after the CJ point, while the 200-nm particles may start to react in the reaction zone.
Źródło:
Central European Journal of Energetic Materials; 2017, 14, 3; 573-588
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Kto się boi księcia Metternicha?
Autorzy:
Tarnawski, Eduard
Powiązania:
https://bibliotekanauki.pl/articles/630372.pdf
Data publikacji:
2013
Wydawca:
Szkoła Główna Handlowa w Warszawie
Tematy:
conservatism, reaction, liberalism
Opis:
Th e author proposes a test for the propensity of being a reactionary that he calls ”Metternich test”, although Robert Stewart Castlereagh (1769–1822) could also be called as an examiner. Undoubtedly only Russian tsars can be considered reactionary monarchs, starting from Nicholas I (1796–1855). To judge whether president Putin is a reactionary we need authority of Alexandr Solzhenitsyn (1918–2008). Although Henry Kissinger is called Metternich of 20th century, he is not suit for the function of examiner. Author elaborates on the faith Metternich had in love as a force that makes politics possible. A person that can’t understand the life of other people, cannot understand history. Aft er Nicholas I became tsar all Russian doctinaires, such as Sergey Uvarov (1786–1855), Konstantin Leontiev (1831–1891) and Konstantin Pobedonostsev 1827–1907), formulated principles of reaction. The paper ends with Wacław Nałkowski’s (1851–1911) critique of Henryk Sienkiewicz as a reactionary.
Źródło:
Kwartalnik Kolegium Ekonomiczno-Społecznego Studia i Prace; 2013, 4; 113-136
2082-0976
Pojawia się w:
Kwartalnik Kolegium Ekonomiczno-Społecznego Studia i Prace
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetic recykling of complex catalysts immobilized on thiol-functionalized polymer supports
Autorzy:
Bączek, N
Strzelec, K.
Wąsikowska, K.
Powiązania:
https://bibliotekanauki.pl/articles/779554.pdf
Data publikacji:
2013
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
encapsulation
magnetic recycling
epoxy resin
supported catalysts
Heck reaction
hydrogenation reaction
Opis:
In this work, the application of the thiol-functionalized epoxy resin encapsulated on magnetic core as supports for palladium catalysts is reported. The study focuses on obtaining of heterogeneous catalysts which can be separated by magnetic field. Palladium complex catalyst [PdCl2(PhCN)2] has been heterogenized by anchoring to these supports via ligand exchange reaction. The characterization of polymeric supports and heterogenized palladium catalysts has involved research methods like time-of-flight secondary ion mass spectrometry (TOF-SIMS), scanning electron microscopy (SEM) and nitrogen BET surface area measurements. The activity and stability during long-term use of the investigated catalytic systems were tested in a Heck and hydrogenation reaction. The influence of the type of thiols used as epoxy hardeners and the morphology of the supports on the catalytic properties of epoxy-supported palladium catalysts was discussed.
Źródło:
Polish Journal of Chemical Technology; 2013, 15, 3; 65-68
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
One-pot three component (LaCl3•7H2O) catalysed biginelli reaction for the synthesis of 1,2,3,4-tetrahydropyrimidine
Autorzy:
Murugesan, C.
Sihabudeen, M. Mohamed
Ahamed, A. Asrar
Powiązania:
https://bibliotekanauki.pl/articles/1190119.pdf
Data publikacji:
2016
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
2
3
4-tetrahydropyrimidine; one pot synthesis
Multicomponent reaction; Biginelli reaction; 1
Opis:
A Series of tetrahydropyrimidine has been derived by LaCl3•7H2O catalysed one pot three component biginelli reaction. The compounds have synthesised from an aldehyde, ethyl acetoacetate and urea or thiourea in an ethanolic medium using a catalytic amount of (LaCl3•7H2O). This method provides quantitative yield and the catalysis can be easily recovered from the reaction medium and be re-used.
Źródło:
World Scientific News; 2016, 35; 87-99
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analiza kinetyki reakcji złożonych na przykładzie rozkładu azotanu amonu
Analysis of the kinetics of complex reactions on the example of the decomposition of ammonium nitrate
Autorzy:
Popławski, D.
Huculak-Mączka, M.
Hoffmann, K.
Hoffmann, J.
Powiązania:
https://bibliotekanauki.pl/articles/125902.pdf
Data publikacji:
2018
Wydawca:
Towarzystwo Chemii i Inżynierii Ekologicznej
Tematy:
kinetyka rozkładu
reakcja złożona
azotan amonu
reaction kinetics
complex reaction
ammonium nitrate
Opis:
W pracy przedstawiono sposób wyznaczenia parametrów kinetycznych złożonej reakcji rozkładu azotanu amonu. W obliczeniach wykorzystano dane pochodzące z pomiarów przeprowadzonych z zastosowaniem skaningowej kalorymetrii różnicowej sprzężonej z termograwimetrią i spektrometrią mas (DSC-TG-MS). Badane próbki ogrzewano z trzema różnymi szybkościami: 3, 5 i 10 K/min. Parametry kinetyczne reakcji rozkładu wyznaczono z zastosowaniem metody dopasowywania modelu, wykorzystując regresję nieliniową. Uzyskane wyniki zdają się potwierdzać współistnienie dwóch konkurujących ze sobą procesów: endotermicznej dysocjacji i odparowania azotanu amonu oraz jego egzotermicznego rozkładu.
The paper presents a method of determining the kinetic parameters of complex reaction of ammonium nitrate decomposition. The data from measurements carried out with the use of differential scanning calorimetry coupled with thermogravimetry and mass spectrometry (DSC-TG-MS) were used in the calculations. The test samples were heated with three different rates: 3, 5 and 10 K/min. Kinetic parameters of the decomposition reaction were determined by model fitting method using nonlinear regression. The obtained results seem to confirm the existence of two competing processes: the endothermic dissociation and evaporation of ammonium nitrate and its exothermic decomposition.
Źródło:
Proceedings of ECOpole; 2018, 12, 2; 561-569
1898-617X
2084-4557
Pojawia się w:
Proceedings of ECOpole
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of a 9-week training intervention on the reaction time of fencers aged 15 to 18 years
Autorzy:
Balkó, Štefan
Rous, Miroslav
Balkó, Iva
Hnízdil, Jan
Borysiuk, Zbigniew
Powiązania:
https://bibliotekanauki.pl/articles/1031761.pdf
Data publikacji:
2017
Wydawca:
PPHU Projack Jacek Wąsik
Tematy:
simple reaction time
choice reaction time
visual stimulus
fencing
training process
Opis:
The purpose of the present study was to determine if it is possible to affect the level of simple (SRT) and choice (CRT) reaction time of fencers with a specific 9-week (in total 350 minutes) training intervention. The research sample consisted of 19 healthy fencers (12 boys, 16±1.1 years and 7 girls, 16.4±0.9 years). Five of the tested subjects were selected as the control group that did not participate in the reaction time training. The training of the experimental group was conducted on an Electronic Fencing Target (EFT-1). All tested individuals completed an entrance and exit reaction time test on the Fitrosword device, which consisted of hitting the target with an epée from the guard position after lighting of an LED light (green, red, yellow) by using various motor responses of the armed arm. No difference in reaction time (SRT, CRT) was found between the experimental and control groups for the entrance test. A significant difference between groups was found for results of the CRT (p = 0.116, d = 0.722) after the 9-week training. A significant difference in CRT was also found between the entrance and the exit tests in the experimental group (p = 0.013, r = 0.469). This difference was not significant in the case of the control group (p = 0.345, r = 0.298). Based on these results, we can assume a positive impact of specific reaction time training on response speed. We can use these results in the training process to improve reaction time, which is an important component of overall sports performance in many combat disciplines, such as karate, boxing, taekwondo, judo, and fencing, as well as motorsports, ball games, etc.
Źródło:
Physical Activity Review; 2017, 5; 146-154
2300-5076
Pojawia się w:
Physical Activity Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sprzężone nitroalkeny jako komponenty nieuzgodnionych reakcji Dielsa-Aldera – najnowsze doniesienia
Conjugated nitroalkenes as components of nonconcerted Diels-Alder reactions – recent studies
Autorzy:
Jasińska, E.
Dresler, E.
Łapczuk-Krygier, A.
Kącka, A.
Nowakowska-Bogdan, E.
Jasiński, R.
Powiązania:
https://bibliotekanauki.pl/articles/142568.pdf
Data publikacji:
2015
Wydawca:
Stowarzyszenie Inżynierów i Techników Przemysłu Chemicznego. Zakład Wydawniczy CHEMPRESS-SITPChem
Tematy:
Nitroalkeny
reakcja Dielsa-Aldera
cykloaddycja
mechanizm
Nitroalkenes
Diels-Alder reaction
cycloaddition reaction
mechanism
Opis:
W pracy przedyskutowano najnowsze doniesienia dotyczące możliwego, nieuzgodnionego przebiegu reakcji Dielsa-Aldera z udziałem sprzężonych nitroalkenów.
In the publication the recent progres concerning non-concerted Diels-Alder reactions with conjugated nitroalkenes has been discussed.
Źródło:
Chemik; 2015, 69, 7; 395-400
0009-2886
Pojawia się w:
Chemik
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The ability to maintain attention during visuomotor task performance in handball players and non-athletes
Autorzy:
Zwierko, Teresa
Florkiewicz, Beata
Fogtman, Sławomir
Kszak-Krzyżanowska, Anna
Powiązania:
https://bibliotekanauki.pl/articles/1054843.pdf
Data publikacji:
2014
Wydawca:
Uniwersytet Szczeciński. Wydawnictwo Naukowe Uniwersytetu Szczecińskiego
Tematy:
sustained attention
handball
reaction time
Opis:
One of the important aspects of attentional processes in sport performance is sustained attention during task execution. The objective of this study was to analyze the ability to maintain attention during a serial reaction time task performance in expert handball players (n = 12) and non-athletes (n = 12). Participants p erform a FitLight TrainerTM (Fitlight Sports Corp., Canada) test protocol configured by the PDA controller which consisted of 10 series of simple motor reaction task to visual stimuli appearing on 8 wireless light discs. Each of the 10 series included 22 reactions. Ability to maintain attention was determined by analyzing the variability in results during testing, e.g. the total time of test execution and the average reaction time to visual stimulus in each subsequent series. The main finding in our study was that Non-athletes in comparison to Athletes had: (1) longer total time of test execution; (2) longer reaction time; (3) and higher variability in results during task performance. The results indicate a higher level of ability to maintain attention in handball players.
Źródło:
Central European Journal of Sport Sciences and Medicine; 2014, 7, 3; 99-106
2300-9705
2353-2807
Pojawia się w:
Central European Journal of Sport Sciences and Medicine
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of in vitro biodegradation on the properties of BNC in the aspect of its use as a material for the cardiac implants production
Autorzy:
Dederko, P.
Walczuk, M.
Malinowska-Pańczyk, E.
Staroszczyk, H.
Kołodziejska, I.
Powiązania:
https://bibliotekanauki.pl/articles/284976.pdf
Data publikacji:
2016
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Polskie Towarzystwo Biominerałów
Tematy:
BNC reaction
cardiac implants
biodegradation
Źródło:
Engineering of Biomaterials; 2016, 19, 138; 19
1429-7248
Pojawia się w:
Engineering of Biomaterials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Use of diamond powder in the ionization process
Autorzy:
Brzecka, P.
Janaszczyk, A.
Chuchracki, M.
Mitura, K.
Powiązania:
https://bibliotekanauki.pl/articles/284028.pdf
Data publikacji:
2017
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Polskie Towarzystwo Biominerałów
Tematy:
diamond powder
ionization
allergic reaction
Źródło:
Engineering of Biomaterials; 2017, 20, no. 143 spec. iss.; 86
1429-7248
Pojawia się w:
Engineering of Biomaterials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Occurrence of total and sulphate sulphur in arable soils of Poznan region and their reaction
Autorzy:
Jakubus, M.
Czekala, J.
Powiązania:
https://bibliotekanauki.pl/articles/799102.pdf
Data publikacji:
1998
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Wydawnictwo Szkoły Głównej Gospodarstwa Wiejskiego w Warszawie
Tematy:
occurrence
sulphate sulphur
arable soil
Poznan region
soil reaction
chemical reaction
natural environment
Opis:
In this work are presented the results of investigations related to total and sulphate sulphur contents in humus horizon of arable soils of 15 Poznań province and their soil reaction. On the basis of obtained results it was found that analysed soils of municipalities contained from 9.0 to 182.0 mg total S/100 g of soil. The data follows that the content of total sulphur was differentiated not only between soils of researched municipalities but also in limit of each other. The quantitative differences of sulphate sulphur, which one content range from 0.03 to 19.7 mg S-SO₄/100g of soil corresponded with the differentiation of total sulphur. Soil reaction of the researched soils like sulphur was differentiated and ranged from pH 3.8 to 7.9.
Źródło:
Zeszyty Problemowe Postępów Nauk Rolniczych; 1998, 456
0084-5477
Pojawia się w:
Zeszyty Problemowe Postępów Nauk Rolniczych
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of in vitro biodegradation on the structure of BNC in the aspect of its use as a material for the cardiac implants production
Autorzy:
Dederko, P.
Walczuk, M.
Staroszczyk, H.
Malinowska-Pańczyk, E.
Kołodziejska, I.
Powiązania:
https://bibliotekanauki.pl/articles/284696.pdf
Data publikacji:
2016
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Polskie Towarzystwo Biominerałów
Tematy:
BNC reaction
cardiac implants
biodegradation
Źródło:
Engineering of Biomaterials; 2016, 19, 138; 20
1429-7248
Pojawia się w:
Engineering of Biomaterials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis of diphenylphosphinic acid esters
Autorzy:
Korzeniowska, Ewelina
Powiązania:
https://bibliotekanauki.pl/articles/763978.pdf
Data publikacji:
2017
Wydawca:
Uniwersytet Marii Curie-Skłodowskiej. Wydawnictwo Uniwersytetu Marii Curie-Skłodowskiej
Tematy:
diphenylphosphinic acid esters, substitution reaction
Opis:
The development of new methods for the synthesis of organophosphorus compounds is still an important part of organic chemistry due to the high demand for these compounds in organic synthesis as well as in asymmetric catalysis. Most of the methods for the synthesis of these compounds include the reactivity of the phosphorus atom, which depending on the structure might exhibit both electrophilic and nucleophilic properties. Herein, I will present the results concerning synthesis of diphenylphosphinic acid esters.
Źródło:
Annales Universitatis Mariae Curie-Skłodowska, sectio AA – Chemia; 2017, 72, 1
2083-358X
Pojawia się w:
Annales Universitatis Mariae Curie-Skłodowska, sectio AA – Chemia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Toward a European Network of Positron Laboratories
Autorzy:
Karwasz, G. P.
Brusa, R. S.
Egger, W.
Ogorodnikova, O. V.
Powiązania:
https://bibliotekanauki.pl/articles/146548.pdf
Data publikacji:
2015
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
positron beams
material science
thermonuclear reaction
Opis:
Some applications of controlled-energy positron beams in material studies are discussed. In porous organic polysilicates, measurements of 3γ annihilation by Doppler broadening (DB) method at the Trento University allowed to trace pore closing and filling by water vapor. In silicon coimplanted by He+ and H+, DB data combined with positron lifetime measurements at the München pulsed positron beam allowed to explain Si blistering. Presently measured samples of W for applications in thermonuclear reactors, irradiated by W+ and electrons, show vast changes of positron lifetimes, indicating complex dynamics of defects.
Źródło:
Nukleonika; 2015, 60, No. 4, part 1; 733-739
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Kontrowersyjne produkty reakcji Maillarda w żywności
Controversial Maillard reaction products in food
Autorzy:
Kruszewski, B.
Obiedziński, M.
Powiązania:
https://bibliotekanauki.pl/articles/270510.pdf
Data publikacji:
2011
Wydawca:
Centralny Ośrodek Badawczo-Rozwojowy Aparatury Badawczej i Dydaktycznej, COBRABiD
Tematy:
reakcja Maillarda
żywność
Maillard reaction
food
Opis:
Reakcja Maillarda to szereg następujących po sobie reakcji pomiędzy cukrami redukującymi a aminokwasami, peptydami i białkami zawierającymi wolną grupę aminową, które prowadzą do utworzenia licznej grupy związków chemicznych. Wpływ na reakcję ma przede wszystkim temperatura ale także czas reakcji, ciśnienie, czy pH środowiska. Grupa nowo powstałych związków nadaje głównie barwę, smak i zapach produktowi spożywczemu. Dane literaturowe wskazują na ich liczne pozytywne i negatywne właściwości. Część substancji uznana została za kancerogenne i mutagenne. Natomiast inne wykazują wysoki potencjał przeciwutleniający, antymutagenny i antyrakowy.
The Maillard reaction is number of successive reactions between reducing sugars and amino acids, peptides and proteins containing a free amino group, which lead to the creation of large group of chemical compounds. Influence on the reaction has mostly temperature but also the reaction time, pressure, or matrix pH. Group of new formed compounds mainly gives color, taste and smell of the food product. Literature data indicate many of their positive and negative properties. Some substances has been recognized as carcinogenic and mutagenic. The second part has high antioxidant, anti-cancer and anti-mutagenic potential.
Źródło:
Aparatura Badawcza i Dydaktyczna; 2011, 16, 4; 37-41
2392-1765
Pojawia się w:
Aparatura Badawcza i Dydaktyczna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Serum metallothionein in newly diagnosed patients with childhood solid tumours
Autorzy:
Krizkova, Sona
Masarik, Michal
Majzlik, Petr
Kukacka, Jiri
Kruseova, Jarmila
Adam, Vojtech
Prusa, Richard
Eckschlager, Tomas
Stiborova, Marie
Kizek, Rene
Powiązania:
https://bibliotekanauki.pl/articles/1040324.pdf
Data publikacji:
2010
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
cancer
Brdicka reaction
serum
marker
metallothionein
Opis:
Tumour markers are substances produced by malignant cells or by the organism as a response to cancer development. Determination of their levels can, therefore, be used to monitor the risk, presence and prognosis of a cancer disease or to monitor the therapeutic response or early detection of residual disease. Time-consuming imaging methods, examination of cerebrospinal fluid or tumour tissue and assays for hormones and tumour markers have been used for cancer diagnosis. However, no specific marker for diagnosis of childhood solid tumours has been discovered yet. In this study, metallothionein (MT) was evaluated as a prospective marker for such diseases. Serum metallothionein levels of patients with childhood solid tumours were determined using differential pulse voltammetry - Brdicka reaction. A more than 5-fold increase in the amount of metallothionein was found in sera of patients suffering from cancer disease, compared with those in sera of healthy donors. The average metallothionein level in the sera of healthy volunteers was 0.5 ± 0.2 μmol · dm-3 and was significantly different (p<0.05, determined using the Schefe test) from the average MT level found in serum samples of patients suffering from childhood solid tumours (3.4 ± 0.8 μmol · dm-3). Results found in this work indicate that the MT level in blood serum can be considered as a promising marker for diagnostics, prognosis and estimation of therapy efficiency of childhood tumours.
Źródło:
Acta Biochimica Polonica; 2010, 57, 4; 561-566
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Differentiation of Visual Sensorimotor Processes in the Representatives of Various Sport Disciplines
Autorzy:
Lesiakowski, Piotr
Krzepota, Justyna
Zwierko, Teresa
Powiązania:
https://bibliotekanauki.pl/articles/1055208.pdf
Data publikacji:
2017
Wydawca:
Uniwersytet Szczeciński. Wydawnictwo Naukowe Uniwersytetu Szczecińskiego
Tematy:
reaction time
selective attention
sport training
Opis:
Sport activities usually require a high efficiency of visual information processing. Therefore, it seems justified to determine the efficiency of visual sensorimotor processes in sports requiring a variety of perception competencies. The aim of this study was to assess the differentiation of sensorimotor processes in terms of simple and choice reaction time, and visual stimulus discrimination in various athletes and untrained persons. The study involved 119 men, of which 95 were athletes: football players (n = 24), volleyball players (n = 22), boxers (n = 26), and rowers (n = 23). The efficiency of sensorimotor processes was evaluated with the Vienna Test System (Schuhfried, Austria). The evaluations included simple reaction time (SRT), choice reaction time (CRT), and visual stimulus discrimination. Analysis of the results showed that volleyball and football players had shorter (p < 0.01) reaction times compared to non-athletes and representatives of the other sports. We found significant differences (p < 0.01) between athletes and non-athletes in visual stimulus discrimination. In addition, boxers showed fewer correct reactions than volleyball players, and shorter times of stimulus detection than in volleyball and soccer players.
Źródło:
Central European Journal of Sport Sciences and Medicine; 2017, 19, 3; 43-53
2300-9705
2353-2807
Pojawia się w:
Central European Journal of Sport Sciences and Medicine
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Adaptation of PCR technique for quantitative estimation of genetic material from different regions of chromosome 21 in cases of trisomy 21.
Autorzy:
Nowacka, Joanna
Helszer, Zofia
Walter, Zofia
Płucienniczak, Andrzej
Kałużewski, Bogdan
Powiązania:
https://bibliotekanauki.pl/articles/1041513.pdf
Data publikacji:
2004
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
quantitative polymerase chain reaction
trisomy 21
Opis:
Pre- and postnatal diagnosis of chromosomal aberrations is generally based on conventional cytogenetic analysis. In this paper, we have devised a quantitative polymerase chain reaction (Q-PCR) method to determine gene dose effects and applied it in cases of regular trisomy 21 as a model. The method is based on quantitative assessment of PCR products after using primers amplifying DNA fragments located in the pericentromeric, heterochromatic, euchromatic and telomeric regions of chromosome 21. A gene dose effect on the amount of PCR product in cases of trisomy 21 was confirmed. Moreover, a correlation between the amount of the PCR product of the examined sequences and their location in the chromosome was observed. The obtained results suggest that the Q-PCR technique can be applied in the diagnosis of aneuploidies.
Źródło:
Acta Biochimica Polonica; 2004, 51, 4; 995-1001
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Kinetics of in In vitro conversion of creatine to creatinine
Kinetyka konwersji kreatyny do kreatyniny In vitro
Autorzy:
Witkowska, A.
Powiązania:
https://bibliotekanauki.pl/articles/1398589.pdf
Data publikacji:
1985
Wydawca:
Instytut Rozrodu Zwierząt i Badań Żywności Polskiej Akademii Nauk w Olsztynie
Tematy:
creatine
creatinine
pH
kinetics of reaction
Opis:
The conversion of creatine to creatinine was studied at 60°C for pH from 1.2 to 7.0. The results showed that the reaction follow a first order rate. The rate constant calculated by use a simple regression technique achieved its maximal value 6.4X 10⁻² per hour at pH 3.4. The relationships between the rate constant and pH were described empirically by means of two parabolic equations, for pH range 1.2 to 3.4: k₁ = -1.92 X 10⁻² + 1.71 X 10⁻²pH + 2.25 X 10⁻³pH², and for pH range from 3.4 to 7.0 : k₂ = 3.07 X 10⁻¹ - 9.95 X 10⁻²pH+ 8.16 X 10⁻³pH².
Reakcję przemiany kreatyny do kreatyniny prowadzono w roztworach przygotowanych z czystego odczynnika kreatyny, techniką ampuł. Co określony czas wyjmowano po 1 próbie, schładzano, kontrolowano pH i oznaczano produkt reakcji, kreatyninę, metodą pikrynianową. Badania wstępne prowadzono w 100°C, w 0,1 mM HCl, przy początkowym stężeniu kreatyny 10 mM, przy pH 1,6. Wykreślenie zależności logarytmu aktualnego stężenia kreatyny [A] do czasu trwania reakcji (t), dawało linię prostą (rys. 1), badana reakcja jest więc pierwszego rzędu. Badania wpływu pH, (w zakresie od 1,2 do 7,0), na szybkość przemiany kreatyny do kreatyniny prowadzono w temperaturze 60°C, przy początkowym stężeniu kreatyny 5 lub 10 mM, w buforach glicynowym, ftalanowym, fosforanowym, z dodatkiem HCl, NaOH albo NaCI. Dane doświadczalne, wyniki oznaczeń kreatyniny w czasie reakcji oraz stałe szybkości reakcji wyliczone prostą techniką regresji, przedstawiono w tabeli 1. Wysokie współczynniki korelacji między stężeniem kreatyniny i czasem trwania reakcji (r ≤ 0,97) potwierdzają, że jest ona pierwszego rzędu. W badanym przedziale pH, graficzne przedstawienie zależności stałej szybkości reakcji lub jej logarytmu - od pH dawały krzywą Gaussa. Najwyższą szybkość reakcji obserwowano przy pH 3,4. Uzyskaną zależność opisano empirycznie za pomocą dwóch równań paraboli, dla zakresu pH od 1,2 do 3,4 i dla zakresu pH od 3,4 do 7,0. Wyliczone równania przedstawiono w tabeli 2. a ich ilustrację, w porównaniu z wynikami doświadczeń, na rys. 2. Dotychczasowe poglądy, według których szybkość badanej reakcji jest najwyższa przy pH 2, mogły być skutkiem braku kontroli pH w czasie i po reakcji. Prowadzenie reakcji w 100°C, zwłaszcza przy wysokim początkowym stężeniu kreatyny w buforach o niskiej pojemności powodowało wzrost pH, a więc i zmiany stałej szybkości reakcji w czasie jej trwania. Prowadzenie reakcji w 40°C przedłużało czas jej trwania do kilku dni Prowadzenie reakcji w temp. 60°C pozwoliło na uzyskanie dużego stopnia przereagowania (dochodzącego do 80% przy pH około 3,4) w czasie 1 doby bez zmian pH środowiska przy zastosowanych buforach.
Źródło:
Acta Alimentaria Polonica; 1985, 11, 2; 263-269
0137-1495
Pojawia się w:
Acta Alimentaria Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of the acrosome reaction on the efficiency of sperm-mediated DNA transfer
Autorzy:
Mu, Y.
Jiang, C.
Jiao, M.
Zhao, Y.
Lv, J.
Liu, Z.
Powiązania:
https://bibliotekanauki.pl/articles/2087625.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
spermatoza
SMGT
acrosome reaction
exogenous DNA
Źródło:
Polish Journal of Veterinary Sciences; 2018, 21, 4; 755-762
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Metody syntezy pochodnych organicznych zawierających wiązanie potrójne węgiel-węgiel
Methods for the synthesis of organic derivatives containing the triple bond carbon-carbon
Autorzy:
Bylińska, I.
Guzow, K.
Powiązania:
https://bibliotekanauki.pl/articles/171636.pdf
Data publikacji:
2012
Wydawca:
Polskie Towarzystwo Chemiczne
Tematy:
wiązanie potrójne
acetylen
synteza
homosprzęganie
heterosprzęganie
reakcja Glasera
reakcja Haya
reakcja Cadiota-Chodkiewicza
reakcja Sonogashiry-Hagihary
triple bond
acetylene
synthesis
homocoupling
heterocoupling
Glaser reaction
Hay reaction
Cadiot-Chodkiewicz reaction
Sonogashira-Hagihara reaction
Opis:
Compounds containing triple bonds are lately in the centre of interest of many research groups. This is mainly connected with their usefulness as substrates to obtain complex compounds with various applications in different areas of science, industry and medicine [1–5]. Because of that many researchers are interested in methods of synthesis of such compounds. As the demand for derivatives with triple bonds is quite big and the one universal method of synthesis does not exist, the new ones are developed or these already known are improved. To enable choosing the best method for synthesis of acetylene derivatives, this review is presented. The oldest methods based on elimination reaction are mentioned [6–9], whereas those enabling incorporation of acetylene unit into more complicated compounds are described more thoroughly [10–92]. The latter methods based on homo- or heterocoupling lead to symmetrical [10–25] and unsymmetrical acetylene and bisacetylene derivatives [26–92]. The most popular reactions such as Glaser reaction (Scheme 1) [10–12], Cadiot-Chodkiewicz reaction (Schemes 11 and 12) [26–49], Hay reaction (Scheme 13) [13, 14] as well as Sonogashira-Hagihara reaction [50–69] and their modifications (Tab. 3) [57] are described. Moreover, the influence of main parameters such as type of substrate used, ratio of reagents, catalyst, base, solvent, reaction time and temperature on the reaction yield is presented (Tabs 1–4) [14, 18, 23, 25, 50–58, 69–78].
Źródło:
Wiadomości Chemiczne; 2012, 66, 9-10; 935-961
0043-5104
2300-0295
Pojawia się w:
Wiadomości Chemiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Nitrogen-doped pyrene as a catalyst for fuel cells
Autorzy:
Chudoba, Anna
Powiązania:
https://bibliotekanauki.pl/articles/1179638.pdf
Data publikacji:
2017
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
DFT
fuel cells
oxygen reduction reaction
Opis:
Density functional theory (DFT) was applied to study nitrogen-doped pyrene as an oxygen reduction reaction (ORR) cathode catalyst for fuel cells. Transition states and energy barriers were calculated to predict the catalytic properties of this substance.
Źródło:
World Scientific News; 2017, 72; 61-68
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Removal of oxidable contaminations contained in submarine atmosphere
Autorzy:
Kłos, R.
Powiązania:
https://bibliotekanauki.pl/articles/259834.pdf
Data publikacji:
2008
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
breathing atmosphere contaminations
submarine
catalytic reaction
Opis:
To remove flammable contaminations from submarine atmosphere, devices for their oxidation and chemical absorption of products resulting from the chemical reaction1, can be applied. In this paper a catalytic system designed for hydrogen and carbon monoxide oxidation and its tests are presented.
Źródło:
Polish Maritime Research; 2008, 3; 67-69
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
How to search herbicide stress in plant system at molecular level?
Autorzy:
Korbin, Małgorzata
Adamczewski, Kazimierz
Twardowski, Tomasz
Powiązania:
https://bibliotekanauki.pl/articles/703392.pdf
Data publikacji:
2009
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
herbicide
corn
plant reaction
molecular analysis
Opis:
Application of herbicides is connected with stress in plant system. Molecular signals of stress are of significant value. How to find them?
Źródło:
Nauka; 2009, 2
1231-8515
Pojawia się w:
Nauka
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical Investigation on the Crucible Discharge of Steel and Slag During the Aluminothermic Welding Process
Autorzy:
Weiss, S.
Riehl, I.
Hantusch, J.
Gross, U.
Powiązania:
https://bibliotekanauki.pl/articles/356989.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
aluminothermic reaction
thermites
SHS
VOF
OpenFOAM
Opis:
The aluminothermic reaction is a type of self-propagating high-temperature synthesis to produce high quality metals and metal oxides en route. The main use of the aluminothermic reaction is in the field of railway welding. The multiphase flow of steel, slag and air in differently shaped crucibles has been numerically investigated in this work with the volume-of-fluid method. The simulations were carried out with the multiphase solver of the open source toolbox OpenFOAM. To validate the numerical results of the three-dimensional simulations, an experiment was carried out to investigate the discharge of a water-oil system from the crucible. A comparison to a numerical 3D simulation showed reasonable accurate results. It can be said that the solver is capable of predicting the point of the oil penetration of the water phase in the experiment.
Źródło:
Archives of Metallurgy and Materials; 2018, 63, 1; 173-180
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis and characterization of fully substituted pyrimidines by using ketene dithioacetal as potent antimicrobial agent
Autorzy:
Khunt, H. R.
Pipaliya, P. P.
Ghelani, S. M.
Babariya, J. S.
Naliapara, Y. T.
Powiązania:
https://bibliotekanauki.pl/articles/412064.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
ketene dithioacetal
pyrimidines
guanidine
biginelli reaction
Opis:
Various ketene dithioacetals of acetoacetanilides were reacted with guanidine nitrate in the presence of base to produce the 2-amino-4-isopropyl-6-alkoxy-N-arylpyrimidine-5-carboxamide derivatives with good yields. All the synthesized compounds were characterized by mass, NMR and IR and also evaluated for antimicrobial activity against five different bacterial and fungal strains. The compounds 4i, 4k and 4l has found comparatively good active against all the bacterial strains.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 5; 134-141
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Green synthesis of pyrimidine derivative
Autorzy:
Sonawane, R. P.
Powiązania:
https://bibliotekanauki.pl/articles/412470.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
dihydropyrimidine derivatives
Biginelli reaction
Grindstone chemistry
Opis:
The majority of the drugs on the market today are entirely chemically synthesized in the laboratory. Several scientists had synthesized dihydropyrimidine (DHPMs) derivatives showing a wide spectrum of biological actions as antibacterials, antivirals as well as antitumor agents. This activity is principally due to presence of steriogenic carbon C4 in their structure. The current investigation is study and synthesis of dihydropyrimidinones efficiently and in high yields under mild, solvent free and eco-friendly conditions by using “Grindstone Chemistry Technique” catalyzed by CuCl2•2H2O and Conc. HCl. The obtained products have been identified by comparison with spectral data & their melting points. The synthesis of DHPMs derivative involves a multicomponent reaction (aldehyde derivative, urea /thiourea and 1,3-dicarbonyl compounds) in presence of HCl / NH4Cl as a catalyst. 3,4-dihydropyrimidin-2-(1H)-ones was synthesized and characterized using IR. The melting points was obtained 203 °C.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 2; 64-68
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparative Study of Chemical Synthesis of Pyrimidine Derivatives by Using Grindstone Chemistry Technique and Conventional Metod
Autorzy:
Sonawane, R. P.
Powiązania:
https://bibliotekanauki.pl/articles/412505.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
dihydropyrimidine derivatives
Biginelli reaction
Grindstone chemistry
Opis:
The majority of the drugs on the market today are entirely chemically synthesized in the laboratory. Several scientists had synthesized dihydropyrimidine (DHPMs) derivatives showing a wide spectrum of biological actions as antibacterials, antivirals as well as antitumor agents. This activity is principally due to presence of steriogenic carbon C4 in their structure. The current investigation is comparative study of chemically synthesis of two DHPMs derivatives by Biginelli Reaction using conventional method and grindstone chemistry technique. The synthesis of DHPMs derivative involves a multicomponent reaction (aldehyde derivative, urea /thiourea and 1,3-dicarbonyl compounds) in presence of HCl / NH4Cl as a catalyst. Two derivative viz. 3,4-dihydropyrimidin-2-(1H)-ones and 3,4-dihydropyrimidin-2-(1H)-thiones were synthesized and characterized using IR. The melting points were obtained are 208 °C and 210 °C respectively. “Grindstone Chemistry Technique” catalyzed by CuCl2•2H2O and Conc. HCl. gave more yield, solvent free and ecofriendly. The obtained products have been identified by comparison with spectral data & their melting points. This study will help to develop easy protocol for the synthesis of many more DHPMs derivative with high field.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 14, 1; 22-27
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of ultrasonic pretreatment on the flotation behavior of galena with and without the presence of pyrite
Autorzy:
Lu, Dongfang
Chen, Lanlan
Ma, Yongyi
Zheng, Xiayu
Wang, Yuhua
Powiązania:
https://bibliotekanauki.pl/articles/1449431.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
galena
ultrasonic pretreatment
flotation
electrochemical reaction
Opis:
Utilizing the ultrasonic pretreatment, flotation tests, ICP-OES, and XPS analysis, the effect of the different ultrasonic pretreatment methods on the flotation behavior of galena were investigated. The flotation recovery of galena was improved for pretreated single galena sample, which is mainly attributed to the efficient removal of the oxidized components and contaminants on the surface of galena by the acoustic cavitation. However, the flotation recovery of galena was decreased when pretreated mixture sample of galena and pyrite was used. Inductively Coupled Plasma Optical Emission Spectrometer (ICP-OES) and X-ray photoelectron spectroscopy (XPS) results reveal that ultrasonic pretreatment facilitates the conversion of $PbS$ to $Pb(OH)_2$ and $PbSO_4$. Besides, the flotation recovery of galena was affected to varying degrees when the galena was mixed with the pyrite of the different particle sizes in the ultrasonic pretreatment process. The reason is that the change in the surface area ratio of these two minerals affects the electrochemical reaction rate between galena and pyrite.
Źródło:
Physicochemical Problems of Mineral Processing; 2020, 56, 4; 611-624
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Chemical reaction algorithm for type-2 fuzzy control optimization in mobile robots
Autorzy:
de la O, D.
Castillo, O.
Soria, J.
Powiązania:
https://bibliotekanauki.pl/articles/384488.pdf
Data publikacji:
2018
Wydawca:
Sieć Badawcza Łukasiewicz - Przemysłowy Instytut Automatyki i Pomiarów
Tematy:
Chemical Reaction Algorithm
control
fuzzy logic
robotics
Opis:
In this work the optimization process of the tracking and reactive controllers for a mobile robot are presented. The Chemical Reaction Algorithm (CRA) is used to find the optimal parameter values of the membership functions and rules for the reactive and tracking controllers. In this case, we are using five membership functions in each variable of the fuzzy controllers. The main goal of the reactive controller is aimed at providing the robot with the ability to avoid obstacles in its environment. The tests are performed on a benchmark maze problem, in which the goal is not necessarily to leave the maze, but rather that the robot avoids obstacles, in this case the walls, and penalizing for unwanted trajectories, such as cycles. The tracking controller’s goal is for the robot to keep into to a certain path, this in order that the robot can learn to react to unknown environments. The optimization algorithm that was used is based on an abstraction of chemical reactions. To perform the simulation we use the “SimRobot” toolbox, the results of the tests are presented in a detailed fashion, and at the end we are presenting a comparison of results among the CRA, PSO and GA methods.
Źródło:
Journal of Automation Mobile Robotics and Intelligent Systems; 2018, 12, 3; 10-19
1897-8649
2080-2145
Pojawia się w:
Journal of Automation Mobile Robotics and Intelligent Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mild Method to Synthesize TATB by Amination of 1,3,5-Trialkoxy-2,4,6-Trinitrobenzene under Phase Transfer Catalysis Conditions
Autorzy:
Chang, T.
Li, B.
Chen, L.
Ge, L.
Lu, M.
Powiązania:
https://bibliotekanauki.pl/articles/358103.pdf
Data publikacji:
2017
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
TATB
phase transfer catalysis
atmospheric amination reaction
Opis:
Nucleophilic amination, as a vital step in the synthesis of 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) using 1,3,5-trialkoxy-2,4,6-trinitrobenzene (TORTNB) and aqueous ammonia as the starting materials and catalyzed by phase transfer catalysis (PTCs) under mild conditions is described. Various phase transfer catalysts, such as crown ethers, tertiary amines, quaternary ammonium salts, poly ethers and cyclodextrin, and various experimental parameters, such as no. of equivalents of PTC, mole ratio of ammonium hydroxide to the starting material, reaction time, reaction temperature and cycle times of the organic phase were investigated. The crown ethers, especially 18-crown-6, show good catalytic activity and re-usability for the amination of 1,3,5-triethoxy-2,4,6-trinitrobenzene giving a yield of 96.52%. This makes for a safe process and suitable for scale-up, because the reactions are carried out under atmospheric conditions. The material synthesised by the new system was characterized by DSC, SEM and LPS.
Źródło:
Central European Journal of Energetic Materials; 2017, 14, 1; 47-59
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Defining Duration of Driver Reaction Time Components Using the NeuroCom Complex
Autorzy:
Zhuk, M.
Kovalyshyn, V.
Tcir, R.
Powiązania:
https://bibliotekanauki.pl/articles/411357.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Oddział w Lublinie PAN
Tematy:
driver reaction time
latent period
functional state
Opis:
The research defines components of driver reaction time under different conditions. The duration of a latent period and time of respective response to a stimulus are determined. It is traced how driver reaction time depends on the complexity of the situation the driver was exposed to. With the help of the NeuroCom complex, computer program and processing of video recordings, the main components of driver reaction time were defined to be information in-flow to the cerebral cortex, detection and recognition of a stimulus, making a right decision and respective reaction. The obtained results can be used for determining dynamic gauge and braking distance of a vehicle, which, in its turn, influences the road safety.
Źródło:
ECONTECHMOD : An International Quarterly Journal on Economics of Technology and Modelling Processes; 2015, 4, 2; 39-44
2084-5715
Pojawia się w:
ECONTECHMOD : An International Quarterly Journal on Economics of Technology and Modelling Processes
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The influence of muscle soreness on the speed of performing a motor reaction speed task in football goalkeepers during a training camp
Autorzy:
Muracki, Jarosław
Powiązania:
https://bibliotekanauki.pl/articles/1030952.pdf
Data publikacji:
2020
Wydawca:
Uniwersytet Szczeciński. Wydawnictwo Naukowe Uniwersytetu Szczecińskiego
Tematy:
DOMS
goalkeeper
muscle soreness
pain
reaction
speed
Opis:
Aim: To investigate the influence of muscle soreness on the speed of performing a motor reaction speed task in football goalkeepers. Methods: Twenty-four young healthy football goalkeepers, aged 1618 years old (average 16.7 ±0.67 year), with an average body height of 175.6 ±5.4 cm and body weight of 65 ±5 kg, participated in a study conducted during a 6-day training camp. The first day, referred to as day 0, was intended for initial tests and the following 5 days, referred to as days 15, consisted of training. On day 0, before the training period, anthropometric parameters such as weight and height were measured, subjects were questioned to determine the rate of perceived exertion (RPE) and perceived psychophysical readiness (PPR), a speed test with motor reaction choice (ST) was performed using a Smart Speed System and areas with muscle soreness (MS) were recorded by means of a computer tablet with the Navigate Pain application. The goalkeepers participated in two training sessions on each of the following 5 days. Before each training session, the same speed test was performed. Lap times for 5 m and 15 m were recorded. After the second training session each day, the participants drew digital pain maps using a computer tablet, marking separate areas of the body where they felt muscle soreness. These data were consolidated and the total area was analyzed to investigate if, throughout the training, there were any changes to the size of the area that was indicated as having MS. A categorization of body areas was also made to determine areas where muscle soreness was most frequently indicated. Each training session was monitored with heart rate (HR) registration and each goalkeeper determined his fatigue (RPE) and readiness to exercise (PPR) on a 110-point scale. Results: Twenty-three out of twenty-four (98.5%) goalkeepers indicated that they had MS during the study. Day 2 showed the highest incidence rate with 21 participants indicating that they felt MS. The biggest area of MS was also indicated on day 2, yet statistical analysis did not show significant differences in the area of MS between the training days. MS was most often indicated in the upper leg, i.e. the thighs. The average time of the first 5 m was 1.3 [s] (SD = 0.09), ranging from 1.28 [s] to 1.33 [s], while the average time of the following 10 m was 2.07 [s] (SD = 0.18), ranging from 2.04 to 2.1 [s]. The average total speed test time equaled 3.37 [s] (SD = 0.21), ranging from 3.33 to 3.38. Statistical analysis did not show significant differences in any of the results between the training days. Conclusions: Most of the goalkeepers felt muscle soreness as an effect of specific goalkeeper training, measured by indicating painful zones on digital pain drawings. In this study, where muscle soreness was induced by technical-tactical specific goalkeeper training, no significant changes were noticed in the speed of performing a motor speed test with reaction choice or on the area of muscle soreness indicated on digital pain drawings, although almost every goalkeeper had a large area of muscle soreness. Discussion: Many studies show that delayed onset muscle soreness (DOMS) causes a decrease in strength, power, range of motion and speed. However, in many cases, these studies are designed to induce high intensity DOMS and then conduct isolated motor skill tests. In this study the objective was not to induce high intensity DOMS but to investigate the effect of muscle pain, which is present naturally during training processes, and then assess its effect on a speed test which reflects real game situations – with a component of reaction choice and change of movement and direction. Approaching the subject from a different viewpoint allows us to see that the reliable assessment of the psychophysical state of players, made by observing their actions on the pitch or even using photocells to measure motion speed, is difficult without an insight into the parameters of soreness that players experience. These can be monitored, for example, through digital pain mapping software.
Źródło:
Central European Journal of Sport Sciences and Medicine; 2020, 32, 4; 27-41
2300-9705
2353-2807
Pojawia się w:
Central European Journal of Sport Sciences and Medicine
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Characterization of bovine serum albumin glycated with glucose, galactose and lactose
Autorzy:
Ledesma-Osuna, Ana
Ramos-Clamont, Gabriela
Vázquez-Moreno, Luz
Powiązania:
https://bibliotekanauki.pl/articles/1040702.pdf
Data publikacji:
2008
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
bovine serum albumin glycoconjugates
Maillard reaction
glycation
Opis:
The non-enzymatic reaction between reducing sugars and proteins, known as glycation, has received increased attention from nutritional and medical research. In addition, there is a large interest in obtaining glycoconjugates of pure well-characterized oligosaccharides for biological research. In this study, glycation of bovine serum albumin (BSA) by d-glucose, d-galactose and d-lactose under dry-heat at 60°C for 30, 60, 120, 180 or 240 min was assessed and the glycated products studied in order to establish their biological recognition by lectins. BSA glycation was monitored using gel electrophoresis, determination of available amino groups and lectin binding assays. The BSA molecular mass increase and glycation sites were investigated by mass spectrometry and through digestion with trypsin and chymotrypsin. Depending on time and type of sugar, differences in BSA conjugation were achieved. Modified BSA revealed reduction of amino groups' availability and slower migration through SDS/PAGE. d-galactose was more reactive than d-glucose or d-lactose, leading to the coupling of 10, 3 and 1 sugar residues, respectively, after 120 minutes of reaction. BSA lysines (K) were the preferred modified amino acids; both K256 and K420 appeared the most available for conjugation. Only BSA-lactose showed biological recognition by specific lectins.
Źródło:
Acta Biochimica Polonica; 2008, 55, 3; 491-497
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Global existence and blow up of solutions for a completely coupled Fujita type system of reaction-diffusion equations
Autorzy:
Rencławowicz, Joanna
Powiązania:
https://bibliotekanauki.pl/articles/1338982.pdf
Data publikacji:
1998
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
reaction-diffusion system
global existence
blow up
Opis:
We examine the parabolic system of three equations $u_t$ - Δu = $v^p$, $v_t$ - Δv = $w^q$, $w_t$ - Δw = $u^r$, x ∈ $ℝ^N$, t > 0 with p, q, r positive numbers, N ≥ 1, and nonnegative, bounded continuous initial values. We obtain global existence and blow up unconditionally (that is, for any initial data). We prove that if pqr ≤ 1 then any solution is global; when pqr > 1 and max(α,β,γ) ≥ N/2 (α, β, γ are defined in terms of p, q, r) then every nontrivial solution exhibits a finite blow up time.
Źródło:
Applicationes Mathematicae; 1998-1999, 25, 3; 313-326
1233-7234
Pojawia się w:
Applicationes Mathematicae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wpływ wymuszonych oscylacji na wydajność autokatalitycznej reakcji chemicznej
Influence of forced oscillations on the performance of autocatalytic chemical reaction
Autorzy:
Zalewski, M.
Powiązania:
https://bibliotekanauki.pl/articles/2072160.pdf
Data publikacji:
2013
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
chaos
oscylacje
reakcja autokatalityczna
oscillations
autocatalytic reaction
Opis:
W pracy została przeanalizowana autokatalityczna izotermiczna reakcja chemiczna prowadzona w przepływowym reaktorze chemicznym z idealnym mieszaniem. W celu określenia wydajności reakcji posłużono się wskaźnikami całkowymi, reprezentującymi średnie stężenia produktów i reagentów. Przedstawiono wpływ zmienności natężenia strumienia zasilającego reaktor na powyższe wskaźniki oraz na przebieg trajektorii czasowych stężeń reagentów i produktów.
Isothermal autocatalytic chemical reaction carried on in a stirred tank reactor is analyzed in the paper. In order to determine the reaction efficiency integral indexes representing average concentrations of reactants and products were used. An impact of variability of reactor feed flow rate on integral indexes and on the course of time trajectory of reactants and products concentrations is showed.
Źródło:
Inżynieria i Aparatura Chemiczna; 2013, 4; 382--383
0368-0827
Pojawia się w:
Inżynieria i Aparatura Chemiczna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Use of pumice and scoria aggregates for controlling alkali silica reaction
Autorzy:
Tapan, M.
Powiązania:
https://bibliotekanauki.pl/articles/110861.pdf
Data publikacji:
2014
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
alkali-silica reaction
aggregate
pumice
scoria
SEM
Opis:
Turkey has important potential pumices reserves (68% of the reserve of the world) and 56 % of pumice reserve of Turkey is in the East Anatolia Region. It is important to assess huge pumice reserves in Eastern Turkey for its use in the cement and concrete industry. Use of acidic pumice and basic pumice (scoria) as cement additive or aggregate are gaining popularity because of their proven structural/durability properties. This paper presents the results of an investigation to assess the effectiveness of pumice and scoria aggregates in controlling alkali silica reaction (ASR) of alkali silica reactive aggregate using the following test methods: the accelerated mortar bar test (ASTM C 1260) and the scanning electron microscopy technique (SEM). The morphologies, structures and properties of the samples were determined by XRD, ICP-MS, XRF and thin section study. Mortar cubes were specially prepared according to ASTM standards using 10, 20 and 30% pumice or scoria aggregate as alkali silica reactive aggregate replacement. The results are compared with ASTM requirements to assess the suitability of pumice or scoria for preventing alkali silica reactivity. According to the results of these methods, pumice aggregates control the alkali silica reaction whereas scoria aggregates decrease expansion but is not as effective as pumice in preventing ASR. The results of SEM analysis showed alkali silica gel formation and serious decomposition of aggregate texture due to ASR in scoria added mortar bars.
Źródło:
Physicochemical Problems of Mineral Processing; 2014, 50, 2; 467-475
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Kinetic Modelling of Betalain Stability and Color Changes in Yogurt During Storage
Autorzy:
Guneser, Onur
Powiązania:
https://bibliotekanauki.pl/articles/1363260.pdf
Data publikacji:
2021-04-20
Wydawca:
Instytut Rozrodu Zwierząt i Badań Żywności Polskiej Akademii Nauk w Olsztynie
Tematy:
natural pigments
betalains
yogurt
reaction kinetics
color
Opis:
Assessment of the storage stability of betalains added to food during processing is crucial to estimate the shelf-life of colored food products and the potency of natural food colorants. The stability of beetroot betalains in yogurt during storage was evaluated in this study. Kinetic experiments were conducted at storage temperatures of 4°C, 10°C, and 20°C. The relationships were also determined between the betalain degradation and lightness (L*), redness (a*), and yellowness (b*). First-order kinetics was observed in the betalain degradation, and the changes in color parameters of the yogurt samples fitted zero-order kinetics. The activation energy required for the degradation of betalains and changes in L*, a*, and b* was found as 104.9, 67.6, 76.5, and 86.1 kJ/mol, respectively. The half-life period of the degradation of red beet betalains was found as 51.43, 30.91, and 4.54 days at 4°C, 10°C, and 20°C, respectively. Multiple linear regression models were also established for betalain content and color parameters. There was a decrease in betalain content and a* color value in the yogurt colored with a beetroot extract during storage. A significant positive correlation was found between pH, a* value, and betalain content in yogurt, while a significant negative correlation was found between betalain content and L* and b* values. Further studies need to be carried out to reveal the relationship between color parameters and natural pigments in food systems.
Źródło:
Polish Journal of Food and Nutrition Sciences; 2021, 71, 2; 135-145
1230-0322
2083-6007
Pojawia się w:
Polish Journal of Food and Nutrition Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Heat effects in the reaction of sulfuric acid with ilmenites influenced by initial temperature and acid concentration
Autorzy:
Jabłoński, Maciej
Lubkowski, Krzysztof
Tylutka, Sandra
Ściążko, Andrzej
Powiązania:
https://bibliotekanauki.pl/articles/1849318.pdf
Data publikacji:
2021
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
ilmenites digestion
sulfuric acid
enthalpy of reaction
Opis:
The influence of temperature and sulfuric acid concentration on the enthalpy and the rate of heat release during the reaction of Norwegian and Australian ilmenites with sulfuric acid was determined. The experimental results obtained from calorimetric measurements were compared with theoretical calculations based on the oxide composition and the phase composition of the raw material. Experimentally determined heat of reaction for Norwegian ilmenite (900–940 kJ/kg) and Australian ilmenite (800–840 kJ/kg) showed good agreement with theoretical calculations based on the phase composition of the raw material. It was found that the enthalpy of ilmenites decomposition reaction does not depend on the concentration of sulfuric acid in the concentration range from 83% to 93%. It was also demonstrated that the temperature and concentration of sulfuric acid have a significant impact on the thermokinetics of the decomposition process, increasing the value of the average rate of temperature change.
Źródło:
Polish Journal of Chemical Technology; 2021, 23, 3; 37-42
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The influence of Iron and Aluminium Powder Pressing on the Course of Shrinkage and Properties of the Fe40Al Phase Obtained by Reaction Sintering
Autorzy:
Berendt-Marchel, M.
Siemiaszko, Dariusz
Powiązania:
https://bibliotekanauki.pl/articles/2048785.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
intermetallic
powder metallurgy
reaction sintering
mechanical properties
Opis:
The effect of the compaction rate on the structure, microstructure and properties of Fe-Al sinters obtained during the SHS reaction is presented in this paper. It was found that increasing the uniaxial pressing pressure led to the increase of the contact area between iron and aluminium particles, which improved the conduction and lowered heat losses during the self-propagating high-temperature synthesis (SHS) reaction and thus result with a sintered material with an improved phase homogeneity. On the other hand, an increase in the pressing pressure causes air be trapped in the pores and later on reacts with iron and aluminium to form oxides. In this work, the shrinkage course was analysed at six different pressing pressures: 50, 100, 150, 200, 300 and 400 MPa. The green compacts were then subjected to the PAIS process (pressure-assisted induction sintering) at a temperature of 1000°C under a load of 100 kN for 5 min. Such prepared samples were subjected to density, porosity, and microhardness (HV0.1) measurements. X-ray diffraction phase analysis and SEM observations were performed together with EDS chemical composition measurements. For studied chemical composition of the samples and sample geometry, 200 MPa compacting pressure was found to be optimal in order to obtain the best sample homogeneity.
Źródło:
Archives of Metallurgy and Materials; 2022, 67, 1; 121-126
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Improved method of isolation of total nucleic acids from hop plants and grapevine before the RT-PCR by addition of polyvinylpolypyrrolidone
Usprawniona metoda izolacji calkowitych kwasow nukleinowych z chmielu i winorosli przez RT-PCR przez dodanie poliwinylopolipirolidonu
Autorzy:
Cajza, M
Folkman, W.
Powiązania:
https://bibliotekanauki.pl/articles/65582.pdf
Data publikacji:
2003
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
isolation
total nucleic acid
nucleic acid
hop plant
grapevine
RT-PCR method zob.reverse transcription polymerase chain reaction
addition
polyvinylpolypyrrolidone
reverse transcription polymerase chain reaction
polymerase chain reaction
Źródło:
Journal of Plant Protection Research; 2003, 43, 4; 375-380
1427-4345
Pojawia się w:
Journal of Plant Protection Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Alkali - carbonate reaction of aggregates
Reaktywność alkaliczna kruszyw węglanowych
Autorzy:
Góralczyk, S.
Powiązania:
https://bibliotekanauki.pl/articles/216015.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Instytut Gospodarki Surowcami Mineralnymi i Energią PAN
Tematy:
reaktywność alkalia-węglany
istota reakcji
metody badań
alkali-carbonate reaction of aggregates
essence of reaction
requirements
methodology
Opis:
In the construction industry carbonate aggregates are commonly used in processes such as concrete production. Aggregates which contain (in their mineral composition) dolomite and an admixture of clay minerals and amorphous silica , can react with alkalis. These reactions can lead to a destructive expansion in concrete. This article explains the mechanisms and the essence of this phenomenon. What is more, some effective and fast methods of the estimation and evaluation of Polish aggregates consisting of carbonate rocks suggests effective methods to determine the usefulness of Polish carbonate aggregates in concrete production are discussed in the paper. Underneath the quality criteria to determine the reactivity of the aggregates will be given. It has been agreed that alkaline reaction and expansion are two separate phenomena related to each other genetically. The aggregates in which reactions caused by clay-siliceous admixtures occur are subjected to expansion. Mineral composition of expansive aggregates as well as their texture indicate that epigenetic dolomites with a distinctive texture are the most reactive. The phase transformations do not end with a complete disintegration of dolomite. They have a cyclical character. They consist of interchangeable reactions of dedolomitization and dolomitization of secondary calcite formed as a result of dolomite's disintegration. The secondary calcite can be effected by Mg+2 ions from pores' solutions and it can form a secondary dolomite. The Mg2+ ions originate from brucite [Mg(OH)2], created in dolomitization process. As a consequence of its reaction with silica, brucite can dissolve and enrich secondary calcite with magnesium. Therefore the reactions which take place in reactive carbonate aggregates and concrete that ismade of it are in fact ongoing processes which consist of dolomite's changes into calcite and vice versa. They are reactions between dedolomitization products (brucite, silica) and products from outside (water, alkalis). The described dedolomitization reactions are a phase of the process that enables expansion due to formation of pressure in inter-granular cracks, with pressure being a result of dry clay-minerals' expansion under the influence of water solutions. Loosening of the aggregate's structure as an effect of dedolomitization reaction makes it easier for water solutions to migrate far into the aggregate's grains followed by their contact with clay minerals.
Kruszywa ze skał węglanowych stosowane są powszechnie w budownictwie między innymi do produkcji betonów. Niektóre z nich, zawierające w swym składzie mineralnym obok dolomitu domieszki minerałów ilastych i bezpostaciowej krzemionki, mogą reagować z alkaliami powodując szkodliwą ekspansję w betonach.W artykule opisano istotę i mechanizmy tego zjawiska oraz zaproponowano efektywne metody oceny przydatności polskich kruszyw ze skał węglanowych do produkcji betonów. Podano kryteria jakościowe oceny reaktywności. Ustalono, że reakcje alkaliczne i ekspansja to dwa oddzielne zjawiska, ale genetycznie powiązane ze sobą. Ekspansji podlegają tylko te kruszywa, w których wystąpiły reakcje spowodowane występowaniem domieszek ilasto- krzemionkowych. Skład mineralny kruszyw ekspansywnych oraz ich tekstura wskazują, że szczególnie reaktywne są dolomity epigenetyczne o charakterystycznej teksturze. Przemiany fazowe nie kończą się z chwilą całkowitego rozpadu dolomitu, lecz mają charakter cykliczny. Składają się one z następujących po sobie na przemian reakcji dedolomityzacji i dolomityzacji wtórnego kalcytu powstałego z rozpadu dolomitu. Wtórny kalcyt może ulegać oddziaływaniu jonów Mg+2 znajdujących się w roztworach porowych i tworzyć wtórny dolomit. Jony Mg+2 pochodzą z powstającego w procesie dedolomityzacji brucytu [Mg(OH)2], który w wyniku reakcji z krzemionką (SiO2) może się rozpuszczać i wzbogacać wtórny kalcyt w magnez. Tak więc reakcje zachodzące w reaktywnych kruszywach węglanowych i betonach z nich wykonanych są procesami ciągłymi polegającymi na kolejnych przemianach dolomitu w kalcyt i odwrotnie, a także reakcją pomiędzy produktami dedolomityzacji (brucyt, krzemionka) i produktami dostarczonymi z zewnątrz (woda, alkalia). Opisane reakcje dedolomityzacji są etapem umożliwiającym tworzenie się zjawiska ekspansji w wyniku powstawania w porach międzyziarnowych ciśnienia jako efekt pęcznienia suchych minerałów ilastych pod wpływem roztworów wodnych. Rozluźnienie struktury kruszywa jako efekt reakcji dedolomityzacji ułatwia migrację roztworów wodnych w głąb ziaren kruszywa i ich kontakt z minerałami ilastymi.
Źródło:
Gospodarka Surowcami Mineralnymi; 2012, 28, 1; 45-62
0860-0953
Pojawia się w:
Gospodarka Surowcami Mineralnymi
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Nowoczesne metody pozyskiwania substancji biologicznie aktywnych przy zastosowaniu reakcji wieloskładnikowych ze szczególnym uwzględnieniem reakcji Ugi
New methods of receive biologically active substances in multicomponent reactions with particular focus on Ugi reaction
Autorzy:
Ryng, S.
Jęśkowiak, I.
Powiązania:
https://bibliotekanauki.pl/articles/172211.pdf
Data publikacji:
2017
Wydawca:
Polskie Towarzystwo Chemiczne
Tematy:
reakcja wieloskładnikowa
reakcja Ugi
synteza organiczna
synteza ukierunkowana na różnorodność
multicomponent reaction
Ugi reaction
diversity-oriented synthesis
Opis:
In the last decade a change of thought has taken place in the pharmaceutical industry which has led to a renaissance of the Multicomponent reactions (MCRs) [1]. Under the inspiration of diversity-oriented-synthesis (DOS), numerous efforts have been devoted to find powerful synthetic tools for rapidly accessing maximum molecular diversity with minimum cost. In the toolbox enabling DOS for generating molecular libraries, MCRs are now recognized as one of the most useful and powerful strategies [2], which provide the highest number of compounds for the least synthetic effort [3]. Following the rapid progress in the research area of MCRs, widespread application has been found in many different areas such as chemical biology, natural product synthesis, pharmaceuticals as well as agrochemistry [2]. The overall aim of a DOS is to generate a small-molecule collection with a high degree of structural, and thus functional, diversity that interrogates large areas of chemical space simultaneously [4]. In Targed-Oriented Synthesis (TOS) a complex target is transformed into a sequence of progressively simpler structures by formally performing chemical reactions in the reverse-synthetic direction [3]. Special subclasses are isocyanide based MCRs (IMCRs). They are particularly interesting because they are more versatile and diverse than the remaining MCRs. Today most MCRs chemistry performed with isocyanides relates to the classical reactions of Passerini and Ugi (Scheme 1)[5]. In Ugi four-component reaction (U-4CR), carboxylic acids, primary amines and oxo components (aldehydes or ketones) react with isocyanides in polar solvents to obtain -amino carboxamides (Schemes 2 and 3). Occasionally however, selective conversion of amide groups into other functional groups is desirable for an increase of diversity of the IMCR-derived compounds [6]. In this reaction two substituted amide groups are formed under release of one equivalent of water. Thus, the U-4CR is an atom-economic and environmentally friendly reaction. It was also shown that water can be used as the solvent. This reaction is typically performed by stirrling the components for approximately 1 day in small quantities of a protic solvent (e.g. methanol or trifluoroethanol) [7]. The examples of Ugi reactions are described in the Schemes 4–10. Multicomponent reactions have become attractive tools in modern synthetic organic chemistry. Among their many advantages, they allow the creation of large chemical libraries of diverse, complex molecular structures, starting from simple materials within a short time frame. Not surprisingly, these particular features have made MCRs especially appealing to medicinal chemists [8].
Źródło:
Wiadomości Chemiczne; 2017, 71, 1-2; 45-63
0043-5104
2300-0295
Pojawia się w:
Wiadomości Chemiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Prolina – pospolity aminokwas wyjątkowy katalizator. Część I, Biosynteza proliny. Wewnątrzcząsteczkowa kondensacja aldolowa
Proline as a common amino acid and an exceptional catalyst. Part I, Proline biosynthesis. Intramolecular aldol reaction
Autorzy:
Wróblewski, M.
Kołodziejska, R.
Studzińska, R.
Karczmarska-Wódzka, A.
Dramiński, M.
Powiązania:
https://bibliotekanauki.pl/articles/172473.pdf
Data publikacji:
2013
Wydawca:
Polskie Towarzystwo Chemiczne
Tematy:
biosynteza proliny
mechanizm kondensacji aldolowej
wewnątrzcząsteczkowa reakcja aldolowa
proline biosynthesis
mechanism of aldol reaction
intramolecular aldol reaction
Opis:
In asymmetric synthesis of organic compounds more effective solutions are being looked for which will result in higher yield(s) of product(s) and their high enantioselectivity [1]. One of such solutions is an use of a multilevel and cheap catalyst. Proline used as a catalyst is a substance of natural origin which was synthetically obtained by Willstätter who was carrying out research on hygric acid (Scheme 1) [10]. The cells of many organisms have a suitable enzymatic system essential for proline biosynthesis [15]. So far, three proline biosynthesis pathways have been described: from glutamate (Scheme 3 and 4), ornithine (Scheme 5 and 6), and arginine (Scheme 7) [16–28]. Proline which is obtained as a result of biosynthesis or supplementation is a substrate for many proteins. Characteristic and significant content (about 23%) of this amino acid was observed in collage. In cells proline can play an important role of osmoregulator [31–35] – a protective substance regulating the activity of such enzymes as catalase and peroxidase [36]. Proline as a secondary amine shows exceptional nucleophilicity facilitating imine and enamine formation. Used as a catalyst in aldol reaction makes with substrates like imine or enamine transition state imitating the activity of naturally occurring enzymes for this type of reaction, that is aldolases. In their research Hajos and Parrish, and Eder, Sauer and Wiechert used proline in intramolecular aldol reaction obtaining proper enones (Scheme 9) [60–62]. The process of intramolecular aldol reaction was used for a separation of racemic mixture of diketones (Scheme 10) [63, 64], cyclization of ortho-substituted aromatic aldehydes and ketones (Scheme 11) [65], synthesis of cyclic diketones (Scheme 13) [68] and domino reaction to obtain substituted cyclohexanones from beta-diketones and unsaturated ketones (Scheme 14) [69].
Źródło:
Wiadomości Chemiczne; 2013, 67, 9-10; 801-818
0043-5104
2300-0295
Pojawia się w:
Wiadomości Chemiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of Exercise and Heat-Load on Simple Reaction Time of University Students
Autorzy:
Chandra, A. M.
Ghosh, S.
Barman, S.
Iqbal, R.
Sadhu, N.
Powiązania:
https://bibliotekanauki.pl/articles/89834.pdf
Data publikacji:
2010
Wydawca:
Centralny Instytut Ochrony Pracy
Tematy:
reaction time
exercise
heat stress
cognitive performance
Opis:
Visual and auditory simple reaction times for both right and left hands of young university male students were recorded with a simple reaction timer, before and after an exercise schedule without and with elevated temperatures in a climatic chamber. The results indicated a decrease in both visual and auditory reaction times after the exercise, but a marked increase in them was noticed when exercise was performed at elevated temperatures. The difference in reaction times in preferred and nonpreferred hands was negligible at rest, i.e., without any exercise and elevated temperature. However, the difference was significant when exercise was performed at elevated temperatures. Visual reaction time was longer than auditory reaction time in all conditions. The results suggest that in hot industries, increased temperature has a specific rather than general effect on cognitive processes, perception and attentiveness, leading to increased chances of human errors, fatal accidents and loss of productivity.
Źródło:
International Journal of Occupational Safety and Ergonomics; 2010, 16, 4; 497-505
1080-3548
Pojawia się w:
International Journal of Occupational Safety and Ergonomics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical solution through mathematical modelling of unsteady MHD flow past a semi-infinite vertical moving plate with chemical reaction and radiation
Autorzy:
Bhandari, A.
Powiązania:
https://bibliotekanauki.pl/articles/178846.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
MHD flow
chemical reaction
radiation
numerical solution
Opis:
In the present manuscript, unsteady magnetohydrodynamic (MHD) flow over a moving porous semi-infinite vertical plate with time-dependent suction has been studied in the presence of chemical reaction and radiation parameters. Time-dependent partial differential equations in the dimensionless form are solved numerically through mathematical modelling in COMSOL Multiphysics. The results are obtained for velocity, temperature and concentration profiles at different times. Steady state results are also presented for different values of physical parameters. The parameters involved in the problem are useful to change the characteristics of velocity, heat transfer and concentration profiles. The numerical solution of partial differential equations involved in the problem is obtained without sacrificing the relevant physical phenomena.
Źródło:
Studia Geotechnica et Mechanica; 2018, 40, 4; 270-281
0137-6365
2083-831X
Pojawia się w:
Studia Geotechnica et Mechanica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Visuomotor processing after progressively increased physical exercise
Autorzy:
Zwierko, Teresa
Lesiakowski, Piotr
Powiązania:
https://bibliotekanauki.pl/articles/1055162.pdf
Data publikacji:
2014
Wydawca:
Uniwersytet Szczeciński. Wydawnictwo Naukowe Uniwersytetu Szczecińskiego
Tematy:
differentiation of visual signal
exercise
reaction time
Opis:
We assessed the effect of physical effort with increasing intensity on the visuomotor processing in physically active young men (n=22). Subjects performed three 10-minute effort-tests with increasing intensity on a cycloergometer. Each participant was assigned individual workload values below the lactate threshold (40% VO2max), at the lactate threshold (60% VO2max) and above the lactate threshold (80% VO2max). Special Ability Signal Test included in the Vienna Test System (Schuhfried, Austria) was used to examine visuomotor processing. The numbers of correct reactions and the median reaction time as a measure of the speed of the detection process were analyzed. Four Signal test recordings were taken: pre-exercise and immediately after the three subsequent effort tests. The numbers of correct reactions increased after the first effort (40% VO2max) in comparison to the pre-exercise state and then significantly decreased after the third effort test (80% VO2max). In contrast, no significant changes in time of signal detection were observed. Physical effort with high intensity might disturb the visuomotor processing in accordance to the accuracy of the visuospatial differentiation of the relevant signal within irrelevant signals.
Źródło:
Central European Journal of Sport Sciences and Medicine; 2014, 5, 1; 27-34
2300-9705
2353-2807
Pojawia się w:
Central European Journal of Sport Sciences and Medicine
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Relationship between assimilable-nutrient content and physicochemical properties of topsoil
Autorzy:
Tkaczyk, Przemysław
Bednarek, Wiesław
Dresler, Sławomir
Krzyszczak, Jaromir
Baranowski, Piotr
Sławiński, Cezary
Powiązania:
https://bibliotekanauki.pl/articles/972810.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Instytut Agrofizyki PAN
Tematy:
soil nutrients
soil reaction
macroelements
microelements
topsoil
Opis:
In the years 2008-2011, an environmental study was conducted for Polish soils, focusing on the south-eastern Poland soils, as they exhibit significant acidification. This study aimed at assessing the current pHKCl and the supply of basic macro- (P, K, Mg and S-SO4) and microelements (B, Cu, Fe, Mn and Zn) in the collected soil samples, and also at determining their relationship with the soil agronomic category, humus content and pH class. Soil reaction and humus and macronutrient content were positively correlated with the amount of colloidal clay and particles < 0.02 mm. In the majority of cases, the macro-element content in the soil was positively correlated with soil pH and humus content. As for microelements, a usually significant and positive correlation was found between the soil agronomic category and the content of manganese, iron and zinc, whereas for the content of boron and copper, no such relationship was observed. A significant and positive correlation between soil reaction and the content of manganese, iron and boron was also found. Such correlations were not observed in relation to copper and zinc content. Statistical analysis indicated that the content of boron and manganese depended to the greatest extent on the investigated physicochemical properties.
Źródło:
International Agrophysics; 2017, 31, 4; 551-562
0236-8722
Pojawia się w:
International Agrophysics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Assessment of the possibility of utilising waste materials from the aluminium production in the copper alloys refining processes
Autorzy:
Bydałek, A. W.
Bydałek, A.
Biernat, S.
Schlafka, P.
Powiązania:
https://bibliotekanauki.pl/articles/382855.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
reaction stimulator
slag
DTA
stymulator reakcji
żużel
Opis:
The analysis of possibilities of utilising waste materials as equivalents of substances stimulating in copper alloys refining processes was presented. The results of thermogravimetric investigations determining the refining ability of the slag with the selected waste materials from the aluminium production were discussed. The possibility of optimisation of the refining slag composition on the basis of the Slag-Prop software was indicated.
Źródło:
Archives of Foundry Engineering; 2013, 13, 4; 15-20
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of antioxidactivity of green and black tea (Camellia sinensis) and rooibos (Aspalathus linearis) tea extracts by means of hplc with reaction detector
Autorzy:
Milašiene, R.
Rawicka, K.
Kornyšova, O.
Ligor, M.
Maruška, A.
Buszewska, B.
Powiązania:
https://bibliotekanauki.pl/articles/346957.pdf
Data publikacji:
2007
Wydawca:
Politechnika Bydgoska im. Jana i Jędrzeja Śniadeckich. Wydział Technologii i Inżynierii Chemicznej
Tematy:
antioxidant activity
HPLC
reaction detector
DPPH
tea
Opis:
Antioxidants are chemical compounds that scavenge free radicals in organisms and protect most important biomolecules such as DNA, proteins, lipids from their damaging activity. Antioxidants reduce a risk of cancer, inflammations, arthritis, cardiovascular diseases and others. The objective of this study was to prepare extracts of different tea species (Camellia sinensis, Aspalathus linearis) in order to compare their antioxidant and radical scavenging activities using reaction detection. Methanolic black, green and red tea extracts were prepared. Reaction detection was used for on-line determination of free radicals of 2,2-diphenyl-1- picrylhydrazil (DPPH) binding by high performance liquid chromatography.
Źródło:
Ars Separatoria Acta; 2007, 5; 27-33
1731-6340
Pojawia się w:
Ars Separatoria Acta
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Researches on the reaction of a pedestrian stepping into the road from the right side from behind and an obstacle realized on the track
Autorzy:
Stańczyk, T. L.
Jurecki, L.
Jaśkiewicz, M.
Walczak, S.
Janczur, R.
Powiązania:
https://bibliotekanauki.pl/articles/244437.pdf
Data publikacji:
2011
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
reaction time
researches of drivers
driver behaviour
Opis:
The paper presents the results of the behaviour of drivers in emergency/risk situations caused by a pedestrian entering the driving lane from the right. They were carried out on Kielce Track in Miedziana Góra. 100 drivers were tested in various age groups at different value risk times behind 0,5s - 3,0 s. The drivers have the opportunity to perform variant defensive manoeuvres: braking, bypassing or braking with bypassing. The researchers used a specially designed, safe model-up a pedestrian, moving on the path of a car from behind the curtains limiting the visibility of the model. The paper presents and analyses the results of measurements of the reaction times of drivers in a risk time function (mental reaction time, psychomotor reaction time while "braking", motor reaction time when braking psychomotor reaction time). The presented results of drivers reaction time confirm the thesis about the influence the risk time on reaction time. Drivers' reaction times confirm the thesis on the influence of the risk time on reaction times, both when turning and braking and also indicate a trend to shorten reaction times in difficult situations. The research method allowed for the capture of many of these disturbances though the fact of such a capture itself does not mean the possibility of their unambiguous interpretation.
Źródło:
Journal of KONES; 2011, 18, 1; 615-622
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Coulometric Determination of Sulphur Compounds Using the Induced lodine-Azide Reaction
Autorzy:
Ciesielski, Witold
Powiązania:
https://bibliotekanauki.pl/articles/896193.pdf
Data publikacji:
2004
Wydawca:
Uniwersytet Łódzki. Wydawnictwo Uniwersytetu Łódzkiego
Tematy:
iodine-azide reaction
coulometric determination
sulphur compounds
Opis:
Wydrukowano z dostarczonych Wydawnictwu UŁ gotowych materiałów
The review summarizes application of coulometry for determination of the sulphur compounds that induce the iodine-azide reaction. The article discusses advantages of the coulometric method. The influence of potassium iodide on induction coefficients is also described. Moreover, determination ranges of several inductors are presented and sensitivities of determination by different methods are compared.
Źródło:
Acta Universitatis Lodziensis. Folia Chimica; 2004, 13
0208-6182
Pojawia się w:
Acta Universitatis Lodziensis. Folia Chimica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of polymerase chain reaction-restriction fragment length polymorphism (RFLP-PCR) in the analysis of single nucleotide polymorphisms (SNPs)
Autorzy:
Tarach, Piotr
Powiązania:
https://bibliotekanauki.pl/articles/1830648.pdf
Data publikacji:
2021-09-29
Wydawca:
Uniwersytet Łódzki. Wydawnictwo Uniwersytetu Łódzkiego
Tematy:
nucleotide polymorphisms
DNA analysis
polymerase chain reaction
Opis:
Polymerase chain reaction-restriction fragment length polymorphism (RFLP-PCR) is a technique used to identify single nucleotide polymorphisms (SNPs) based on the recognition of restriction sites by restriction enzymes. RFLP-PCR is an easy-to-perform and inexpensive tool for initial analysis of SNPs potentially associated with some monogenic diseases, as well as in genotyping, genetic mapping, lineage screening, forensics and ancient DNA analysis. The RFLP-PCR method employs four steps: (1) isolation of genetic material and PCR; (2) restriction digestion of amplicons; (3) electrophoresis of digested fragments; and (4) visualisation. Despite its obsolescence and the presence of high-throughput DNA analysis techniques, it is still applied in the analysis of SNPs associated with disease entities and in the analysis of genetic variation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). RFLP-PCR is a low-cost and low-throughput research method allowing for the analysis of SNPs in the absence of specialised equipment, and it is useful when there is a limited budget.
Źródło:
Acta Universitatis Lodziensis. Folia Biologica et Oecologica; 2021, 17; 48-53
1730-2366
2083-8484
Pojawia się w:
Acta Universitatis Lodziensis. Folia Biologica et Oecologica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determinants of fiscal effort in sub-Saharan African countries: Does conflict matter?
Autorzy:
Okwoche, Princewill U.
Iheonu, Chimere O.
Powiązania:
https://bibliotekanauki.pl/articles/1837855.pdf
Data publikacji:
2021-06-30
Wydawca:
Uniwersytet Ekonomiczny w Poznaniu
Tematy:
sfical reaction functions
conflict
sub-Saharan Africa
Opis:
This study investigates the determinants of fiscal effort in sub-Saharan African (SSA) within the framework of fiscal reaction functions. Whereas previous studies focusing on SSA have mainly considered the economic non-debt determinants this study accounts for the role of conflict given its persistence in many SSA countries. It employs a variety of panel econometric methods that are applicable in tackling the problem of endogeneity. Specifically the study employs the instrumental variables fixed effects, the two-step generalised method of moments (GMM) and the traditional two-stage least squares techniques. Mainly the evidence shows that although SSA governments have made fiscal adjustments in response to the escalating levels of debt, conflict impacts negatively on this response in SSA. Furthermore, the results affirm the presence of fiscal fatigue in SSA’s fiscal reaction function. Recommendations based on these findings are discussed.
Źródło:
Economics and Business Review; 2021, 7, 2; 50-73
2392-1641
Pojawia się w:
Economics and Business Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Kinetic Studies of Pt(IV) Chloride Complex Ions Reduction Reaction Using Potassium Formate
Autorzy:
Wojnicki, M.
Żabiński, P.
Csapó, Edit
Powiązania:
https://bibliotekanauki.pl/articles/351194.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
platinum
recovery
recycling
activation energy
reaction mechanism
Opis:
In this paper, the kinetics of the platinum(IV) chloride complex ions reduction reaction was studied. It was shown that the mechanism exhibits autocatalytic character. The presence of metallic platinum in the system significantly increases the reaction rate. The influence of the initial concentration of precursor, reductant, ionic strength, initial concentration of the chloride ions as well as the temperature on the process rate was investigated. The activation energy was determined and is equal to 93.57 kJ/mol. Moreover, the obtained metallic phase was analyzed, and it was observed that it has a micrometric size.
Źródło:
Archives of Metallurgy and Materials; 2020, 65, 3; 1135-1140
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Odczucie wstrętu może wyzwolić reakcję neurokardiogenną – opis przypadku.
Disgust may elicit neurocardiogenic reaction – case report.
Autorzy:
Sławuta, Agnieszka
Zyśko, Dorota
Powiązania:
https://bibliotekanauki.pl/articles/470097.pdf
Data publikacji:
2012
Wydawca:
Europejskie Centrum Kształcenia Podyplomowego
Tematy:
odczucie wstrętu
reakcja neurokardiogenna
disgust
neurocardiogenic reaction
Opis:
W pracy przedstawiono opis przypadku 63-letniej kobiety z licznymi incydentami zasłabnięć w przebiegu reakcji neurokardiogennych wywołanymi odczuciem wstrętu, jaki został wywołany różnymi bodźcami. Widok zmasakrowanych zwłok ludzkich doprowadził do ciężkiego stanu przedomdleniowego, który przejawiał się bardzo silnym osłabieniem, zaburzeniami widzenia, wymiotami. W pracy omówiono znaczenie wstrętu jako czynnika prowokującego reakcję neurokardiogenną.
63-year-old woman presented with numerous presyncopal events caused by neurocardiogenic reaction provoked by disgust evoked by different stimulus. The sight of mutilated human body elicited strong presyncopal event with faintness, visual disturbances, vomitus. The importance of disgust as a factor provoking the neurocardiogenic reaction was discussed.
Źródło:
Współczesne Pielęgniarstwo i Ochrona Zdrowia; 2012, 3; 64-65
2084-4212
Pojawia się w:
Współczesne Pielęgniarstwo i Ochrona Zdrowia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Screening of the catalytic activity of pd0 and pd2+- supported on chitosan beads and cryogels
Autorzy:
Pestov, Aleksandr
Mekhaev, Aleksandr
Privar, Yuliya
Prokuda, Natalya
Modin, Evgeniy
Bratskaya, Svetlana
Powiązania:
https://bibliotekanauki.pl/articles/1034532.pdf
Data publikacji:
2018
Wydawca:
Sieć Badawcza Łukasiewicz - Polskie Towarzystwo Chitynowe
Tematy:
Heck reaction
catalysis
chitosan
cryogel
hydrodechlorination
hydrogenation
Opis:
Here, we report the results of screening of the catalytic activity of Pd-containing chitosan beads and cryogels in the cross-coupling reaction, hydrogenation of alkenes, nitro-, and carbonyl compounds and the hydrodechlorination of chlorophenols. Pd0-containing chitosan beads and cryogels show moderate catalytic activity in the reduction of alkenes and nitroaromatics. The conversion of nitroaromatics decreases for substrates with electron-withdrawing substituents, while the conversion of alkenes increases with the activation of carbon-carbon double bonds. For several substrates, a significant difference in kinetics and conversion degrees was observed for Pd nanoparticles supported on chitosan beads and cryogels. It was found that conversion in the hydrodechlorination reaction depends on substrate structure, being higher for substrates containing substituents with a positive mesomeric effect. Pd2+-chitosan catalysts showed high catalytic activity in cross-coupling (Heck reaction) offering the following advantages over known catalytic systems: lower reaction temperature, the selective functionalisation of C-I bonds, and the possibility to perform reactions with iodobenzene without base addition.
Źródło:
Progress on Chemistry and Application of Chitin and its Derivatives; 2018, 23; 149-158
1896-5644
Pojawia się w:
Progress on Chemistry and Application of Chitin and its Derivatives
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Satysfakcja pozakupowa i dysonans pozakupowy jako czynniki determinujące reakcje konsumenckie
After-purchase satisfaction and after-purchase dissonance as factors determining consumer reactions
Autorzy:
Grupa, Rafał
Powiązania:
https://bibliotekanauki.pl/articles/501357.pdf
Data publikacji:
2012
Wydawca:
Instytut Studiów Międzynarodowych i Edukacji Humanum
Tematy:
after-purchase dissonance
consumer reaction
marketing
consumer
Opis:
This article attempts to determine what psychological factors make the man choose and purchase a particular product or service. It is an obvious fact indeed that after any purchase, there are various kinds of feelings associated with it – ranging from extreme dissatisfaction to satisfaction and even delight. It is the role of the following article to present the elements which determine after-purchase sentiments.
Źródło:
Społeczeństwo i Edukacja. Międzynarodowe Studia Humanistyczne; 2012, 1(9); 483-494
1898-0171
Pojawia się w:
Społeczeństwo i Edukacja. Międzynarodowe Studia Humanistyczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mathematical modeling to optimize the product in enzyme kinetics
Autorzy:
Nandi, S.
Ghosh, M. K.
Bhattacharya, R.
Roy, P. K.
Powiązania:
https://bibliotekanauki.pl/articles/206501.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
enzyme kinetics
optimization
optimal control approach
reversible reaction
Opis:
Optimization of product in enzyme kinetics is successful by the showers of mathematical analysis with control measures. Enzymes are an important functional aspects of all biochemical processes, as they catalyze numerous reaction taking place within living organisms. With this view, optimization and quantification of product is stressed upon and in such a context, optimal control approaches have been applied in our study. In this article, we have formulated a mathematical model of enzymatic system Dynamics with control measures with a view to optimize the product as well as process conditions. Here, Pontryagin Minimum Principle is used for determination of optimal control with the help of Hamiltonian. We discuss the relevant numerical solutions for the concentration of substrate, enzyme, complex and product with respect to a specified time interval by varying control factors.
Źródło:
Control and Cybernetics; 2013, 42, 2; 431-442
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Enancjoselektywna enzymatyczna desymetryzacja katalizowana oksydoreduktazami. Reakcje utleniania. Część 1
Enantioselective enzymatic desymmetrization catalyzed by oxidoreductases. Oxidation reactions. Part 1
Autorzy:
Karczmarska-Wódzka, A.
Kołodziejska, R.
Tafelska-Kaczmarek, A.
Studzińska, R.
Wróblewski, M.
Augustyńska, B.
Powiązania:
https://bibliotekanauki.pl/articles/172799.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Chemiczne
Tematy:
dehydrogenaza
monooksygenaza
reakcja utleniania
dehydrogenase
monooxygenase
oxidation reaction
Opis:
The main advantage of biotransformation involving enzymes, compared to chemical processes, is a highly selective formation of products with precise configuration. Herein we describe enzymes participating in the oxidation processes, especially dehydrogenases and monooxygenases. Dehydrogenases are not only able to catalyze the enantioselective reduction of prochiral ketones, but they can also desymmetrize meso and prochiral diols through the enantioselective oxidation. As a result of this processes, optically active hydroxyketones, hydroxycarboxylic acids, and their derivatives are obtained. Cytochrome P450 monooxygenases (CYPs) constitute a family of heme-containing enzymes which exhibits a variety of catalytic activities. They catalyze different reactions, such as hydroxylation, epoxidation, oxidative deamination, or N- and (S)-oxidation. In the oxidation reaction with monooxygenases, the whole cells are commonly used as catalysts. The use of monooxygenases in the oxidation reaction of prochiral alkanes provides the optically active alcohols. It is very significant that these transformations are still difficult to carry out by chemical methods. Baeyer-Villiger monooxygenases (BVMO EC 1.14.13.X) effectively catalyze the nucleophilic and electrophilic oxidation reactions of various functional groups. BVMO are highly regio- and stereoselective enzymes, and their catalytic potential is used in the synthesis of optically pure lactones and esters. Keywords:
Źródło:
Wiadomości Chemiczne; 2015, 69, 1-2; 35-51
0043-5104
2300-0295
Pojawia się w:
Wiadomości Chemiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The research on drivers behaviour on a car track in a simulated accident situation
Autorzy:
Stańczyk, T. L.
Jurecki, R. S.
Karendal, M.
Pieniążek, W. S.
Powiązania:
https://bibliotekanauki.pl/articles/246093.pdf
Data publikacji:
2009
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
pre-accident situations
driver behaviour
driver reaction time
Opis:
The following work presents research of driver behaviour in pre-accident situations conducted on Kielce Car Track within a research project N509016 31/1251. The aim of the following research work is the completion and extension of the knowledge concerning reaction times and an update to an existing data base. At the same time, driver behaviours in a particular pre-accident situation are analysed. The tests are conducted with a relatively big group of drivers, of different age and different driving experience. Reaction times are determined for three event scenarios, as it was previously mentioned, the type of scenario can significantly influence on obtained values of these times. The research conducted in a pre-arranged risk situation, where an obstacle in a form of a car mock-up suddenly forces its way into a road area with a simultaneous limitation of "room" for a manoeuvre by a lorry mock-up moving on the opposite lane and opposite direction. This work presents the pattern and scenario course of a pre-accident situation selected for tests. Measuring equipment and movable mock-ups used for research were characterised. There were presented selected, preliminary results of three trials characterised by different values of risk time (different level of accident risk). The following article presents the patterns of the first pre-accident situation under research, the research method and example research results obtained on Kielce Track.
Źródło:
Journal of KONES; 2009, 16, 1; 473-482
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A convergent approach for the synthesis of new pyrazolyl bipyridinyl substituted coumarin derivatives as antimicrobials
Autorzy:
Bhila, V. G.
Chovatiya, Y. L.
Patel, C. V.
Giri, R. R.
Brahmbhatt, D. I.
Powiązania:
https://bibliotekanauki.pl/articles/411982.pdf
Data publikacji:
2015
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Coumarin
Bipyridine
Pyrazole
Kröhnke’s reaction
antimicrobial activity
Opis:
Some new 3-[3-(1-phenyl-3-aryl-1H-pyrazol-4-yl)acryloyl]coumarins 3a-f were synthesized (coumarin chalcones) by the condensation of various 3-acetyl coumarins 1 and appropriate 1-phenyl-3-aryl-1H-pyrazole-4-carbaldehyde 2. These coumarin chalcones 3a-f were then employed for the synthesis of pyrazolyl bipyridinyl substituted coumarins 7a-f, 8a-f, and 9a-f under Krohnke’s reaction condition. The characterization of all the synthesized compounds was carried out by elemental analysis, IR, 1H-NMR, 13C-NMR, DEPT-135 and mass spectral analysis. In addition to that, in vitro antimicrobial competency of the title compounds was assessed against selected pathogens. Compounds 3b, 3e, 7b, 8b, 8c and 9b exhibited excellent antimicrobial activity and said to be the most proficient members of the series.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2015, 40; 1-16
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Gewald reaction for the synthesis of benzo[4,5]-thieno[2,3-d]pyrimidin-4(3H)-one derivatives and it’s antimicrobial study
Autorzy:
Dhuda, Gautamkumar
Ladwa, Paresh
Modha, Jayesh J.
Powiązania:
https://bibliotekanauki.pl/articles/1031419.pdf
Data publikacji:
2021
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Antimicrobial Study
Benzo[4-5]thienopyrimidines
Gewald Reaction
Opis:
A variety of schiff base of 3-amino-2,7-dimethyl-5,6,7,8-tetrahydrobenzo[4,5]thieno[2,3-d]pyrimidin-4(3H)-one have been synthesized using novel and yield efficient protocol i.e., Gewald condensation reaction by four step processes. The characterization of synthesized diverse molecules was characterized by various spectroscopic methods such as IR, Mass, and NMR. The hybrids of thieno-pyrimidines were utilized to check their efficiency as anti-microbial activity against various Gram-positive (S. aureus, S. pyogenes, MRSA- multi-resistance S. aureus) and Gram negative (E. coli, P. aeruginosa, Klebsiella pneumonia) bacteria, using five anti-microbial agents as reference standard. It was found that 4a (anti-fungal agent) and 4e (anti-bacterial agent) shown best efficiency and which can lead in the area of medicinal field.
Źródło:
World Scientific News; 2021, 151; 110-122
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The influence of sprint block start elements on initial velocity of 100 metre race
Autorzy:
Terczyński, Robert
Powiązania:
https://bibliotekanauki.pl/articles/1054601.pdf
Data publikacji:
2014
Wydawca:
Uniwersytet Szczeciński. Wydawnictwo Naukowe Uniwersytetu Szczecińskiego
Tematy:
laser
reaction time
speed measurement
sprint start
velocity
Opis:
The aim of this paper was to investigate whether it is possible to evaluate the relationship between different phases of sprint start objectively. The participants of the research were the top level of elite National Sprint Team (8 female, 9 male). The run times were as follows: 10.39 ±0.12 s for men and 11.63 ±0.20 s for women. The data that were taken into account during the research in order to examine typical kinetic parameters of the sprint start were: reaction time, delay between simple reaction time and reaction time (IAAF), time to front peak force, time to rear peak force, delay between end of front force and gun signal and total start time. The analysis of the study identifies the major kinematic parameters of the phases of the sprint start and block acceleration that influence the results of sprint running. The following correlation analyses were conducted, a linear regression for the typical kinetic parameters of the sprint start, initial speed on 100 metre race. Finally, a simple coaching related model for the development of sprinting is presented which is consistent with scientific evidence recommendations for coaches to make changes in training.
Źródło:
Central European Journal of Sport Sciences and Medicine; 2014, 8, 4; 87-96
2300-9705
2353-2807
Pojawia się w:
Central European Journal of Sport Sciences and Medicine
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Reaction of Coniferous Forest Vegetation to Particulate Deposition Under Alkaline Pressure
Autorzy:
Świercz, Anna
Powiązania:
https://bibliotekanauki.pl/articles/970623.pdf
Data publikacji:
2011
Wydawca:
Uniwersytet Łódzki. Wydawnictwo Uniwersytetu Łódzkiego
Tematy:
Scotch pine forests
cement dust emission
needles
reaction
Opis:
The aim of this study was to determine direction, rate and character of the changes in coniferous forest communities caused by anthropogenic stress factors (alkaline emission and imission) changing with time. To fulfil this goal, we have performed comprehensive studies of soils and plants at the study sites located in coniferous forest communities remaining under direct influence of cement and lime industry in the Świętokrzyskie Voivodeship. There were differences in the accumulation of elements in pine needles collected at alkalized sites in comparison with needles from the control site: Ca content was 2.5 times higher and Cu, Pb and Sr contents were 2–3 times higher, while Al and Fe, and Mn contents were twice and 10 times lower respectively. SEM analysis of morphological features of pine needle surface, in particular degree of preservation of epicuticular waxes can be as an indicator of assimilatory organ degeneration caused by dust deposition which induces wax layer erosion. Declining species number and biodiversity, particularly conspicuous at the Sitkówka site, was a general tendency observed over the study period (from 18 to 10 years). Other noticeable processes include slow regenerative changes of the community with a tendency towards higher contribution of acidophilic coniferous forest species with lower light and temperature requirements and suppression of meadow, ruderal and associated taxa. Further studies are required in order to define succession rate and direction of changes in species composition of these communities.
Źródło:
Acta Universitatis Lodziensis. Folia Biologica et Oecologica; 2011, 7; 229-246
1730-2366
2083-8484
Pojawia się w:
Acta Universitatis Lodziensis. Folia Biologica et Oecologica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Rice Blast Biology and Reaction of Host to the Disease
Autorzy:
Zewdu, Zelalem
Powiązania:
https://bibliotekanauki.pl/articles/1839725.pdf
Data publikacji:
2021
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Rice
Blast
Magnaporthe grisea
Magnaporthe oryzae
Host Reaction
Opis:
Rice blast (Magnaporthe grisea) is first reported in China and then in Africa in1922. The disease is now the most widespread and devastating rice disease in all rice producing areas of the world. The disease can cause from mild yield reduction to total crop loss as depends on the variety and severity level. The rice blast isolate is closely related to the isolate of other blast like fungus and distinctly described as Magnaporthe grisea. Rice blast fungus starts the infection cycle after a three-celled conidium lands on the rice leaf surface. Thousands of spores can be produced from a single lesion within 15 days after infection. Symptoms on leaves start as small brown necrotic lesions that evolve to larger elliptical or spindle-shaped lesions, colored whitish to gray with darker borders while infected seeds display brown spots, which may result from the infection of the florets as they matured into seeds. The rice blast needs at least a 12-hour period of moderate temperatures (25 to 30 °C), high relative humidity (90-92 %), and high moisture which are conducive for its development. The disease can be managed by using resistant varieties, using integrated disease management options and nutrient managements like application of recommended nitrogen fertilizers and application of silicon fertilizers. The rice plant responds differently for reducing the occurrence and damage of the disease either fungus is incapable causing sporulating lesions on the plant or the plant develop residual resistance that remains when complete resistance has been overcome by the pathogen.
Źródło:
World News of Natural Sciences; 2021, 39; 11-21
2543-5426
Pojawia się w:
World News of Natural Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fe-Al based composite reinforced with ultra-fine Al2O3 oxides for high temperature applications
Autorzy:
Kopec, Mateusz
Jóźwiak, Stanisław
Kowalewski, Zbigniew
Powiązania:
https://bibliotekanauki.pl/articles/2055052.pdf
Data publikacji:
2021
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
cermet composites
reaction synthesis
powder method
electron microscopy
Opis:
In this paper, an Fe-Al based composite reinforced with ultra-fine Al2O3 oxides was obtained through sintering of aluminium, iron and mullite ceramic powders using self-propagated high temperature synthesis (SHS). The powder mixture with a 50%wt. content of the ceramic reinforcement was cold pressed and subsequently subjected to the sintering process in vacuum at 1200◦C for 25 minutes under external loading of 25 kN. The complex microstructure of the Fe-Al matrix reinforced with ultra-fine Al2O3 oxides was found to be desired in high temperature applications since only 3% of the relative weight gain was observed after 100 hours of annealing at 900◦C.
Źródło:
Journal of Theoretical and Applied Mechanics; 2021, 59, 3; 509--513
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zastosowanie reakcji Fentona do wspomagania biologicznego oczyszczania ścieków z przemysłu mleczarskiego
Application of Fenton Reaction for Supporting Biological Wastewater Treatment from the Dairy Industry
Autorzy:
Krzemińska, D.
Neczaj, E.
Parkitna, K.
Powiązania:
https://bibliotekanauki.pl/articles/1819268.pdf
Data publikacji:
2013
Wydawca:
Politechnika Koszalińska. Wydawnictwo Uczelniane
Tematy:
reakcja Fentona
biologiczne oczyszczanie ścieków
wastewaters
Fenton reaction
Opis:
The dairy industry is one of the most polluting of industries, not only in terms of the volume of effluent generated, but also in terms of its characteristics as well. The composition of waste water produced in the milk processing plants depends primarily on the type of production (such as fluid milk, butter, cheese, buttermilk, whey, yogurt, condensed milk, flavored milk, milk powder, ice cream, etc.). The factors influencing the composition and charge of waste water are the raw materials used, level of technology plant, cleaning and disinfection processes and the amount of water used. Still increased pollution, combined with increased industrial activity and increasingly restrictive laws concerning discharges, focuses on the problem of optimal industry wastewater treatment. High concentration of organic matter in dairy wastewater causes problems with their removal in biological methods. Combining advanced oxidation process (AOP) and biological process has received attention in recent years as a promising alternative for industrial wastewater treatment. Among biological treatment processes the sequencing batch reactor (SBR) have been widely applied for treating dairy wastewater. The advantages of this technology can include high flexibility and ease of adaptation of operating parameters. Sequencing batch reactor is the name given to wastewater treatment systems based on activated sludge, operated on a sequence changes of anaerobic and aerobic conditions in one reactor. Using AOP pretreatment is important to improve the biodegradability and produce an effluent that can be treated biologically These processes involve the generation of highly free radicals, mainly hydroxyl radical (HO) via chemical, photochemical and photocatalytic reactions. One of the most important AOP process is Fenton reaction. Effectiveness of Fenton reaction has been confirmed in the case of pharmaceutical wastewater, treatment of brines or treatment of paper pulp manufacturing effluents. The oxidation system based on the Fenton’s reagent (hydrogen peroxide in the presence of a ferrous salt under acidic conditions) has been used for the treatment of both organic and inorganic substances of the wastewater stream. The present study was aimed to treat the dairy wastewater by Fenton’s process and an aerobic sequencing batch reactor. The first part of this study examined the effect of operating conditions on Fenton`s process pretreatment of dairy wastewater. The effectiveness of the AOP pretreatment was assessed by evaluating wastewater biodegradability enhancement (BOD5/COD), as well as monitoring major pollutant concentrations (COD) with reaction time. The optimum dose Fe2+ and H2O2 was found to be 1.2 and 2.0 g/L, respectively. In a single biological treatment the average removal efficiencies of COD, and NH4+ were 67%, and 61%, respectively. Integration of Fenton`s process and biological treatment resulted in 93% removal of COD and 79% NH4+ from the dairy wastewater. The results indicated that the combined process would be a promising alternative for the treatment of dairy wastewater.
Źródło:
Rocznik Ochrona Środowiska; 2013, Tom 15, cz. 3; 2381-2397
1506-218X
Pojawia się w:
Rocznik Ochrona Środowiska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Polymorphism in Syringa rDNA regions assessed by PCR technique
Autorzy:
Smolik, M.
Andrys, D.
Franas, A.
Krupa-Malkiewicz, M.
Malinowska, K.
Powiązania:
https://bibliotekanauki.pl/articles/41641.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Instytut Dendrologii PAN
Tematy:
polymorphism
lilac
Syringa
rDNA region
polymerase chain reaction
Opis:
The Syringa genus is characterizedby a multiplicity of forms. Its chief asset is the ornamental value of thousands of accessions, species or hybrids. From a phylogenetic point of view the genus is difficult in an explicit classification due to its frequently complex genome. The aim of this study was to determine the possibility for the identification of genotypic diversity and genetic relationships in the nrDNA sequence of some selected Syringa accessions – part of a collection of the Dendrological Garden in Przelewice (Poland). For this purpose, the PCR technique together with a combination of various ‘universal’ primers designed for the nrDNA sequence analysis were employed. Fourteen Syringa accessions: Syringa × chinensis Willd., S. × prestoniae Mc Kelv., S. × prestoniae ‘Telimena’, S. × prestoniae ‘Jaga’, S. × prestoniae ‘Basia’, S. meyeri ‘Palibin’, S. vulgaris ‘Miss Ellen Willmott’, S. vulgaris, S. vulgaris ‘Jules Simon’, S. vulgaris ‘Katherine Havemeyer’, S. vulgaris ‘Krasawica Moskvy’, S. vulgaris ‘Mirabeau’, S. vulgaris ‘Madame Lemoine’ and S. vulgaris ‘Niebo Moskvy’ made up the research material. In the conducted amplifications, genetic profiles were obtained for 14 combinations among the 25 combinations of different pairs of primers used. The nrDNA templates coding the small subunit (SSU), 5.8S subunit andITS1, ITS2 andIGS sequences were amplified. In PCR reactions a total of 33 PCR products were generated, of which 21 (64%) products were polymorphic, 6 (18%) monomorphic and6 (18%) were genotype-specific. For the lilac accessions examined246 amplicons were generated from ~230 to ~1100 bp in length. The analysis of both the dendrogram and the genetic similarity matrix revealedlow diversity between the examinedaccessions. For most they rangedfrom 70 to 80%, andthe greatest diversity (87%) was foundbetween the S. × prestoniae: ‘Basia’ and‘Telimena’ accessions, while the lowest (57%) was observed between S. vulgaris ‘Katherine Havermeyer’ and S. × chinensis.
Źródło:
Dendrobiology; 2010, 64
1641-1307
Pojawia się w:
Dendrobiology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Uwarunkowania i pomiar podatności na dystrakcję u starszych kierowców
Conditions and measurement of the older drivers’ susceptibility to distraction
Autorzy:
Tarnowski, A.
Olejniczak, A.
Powiązania:
https://bibliotekanauki.pl/articles/107309.pdf
Data publikacji:
2016
Wydawca:
Instytut Transportu Samochodowego
Tematy:
kierowca
wiek
reakcja
dystrakcja
driver
age
reaction
distraction
Opis:
Artykuł prezentuje wyniki analiz przeprowadzone na podstawie bazy wyników testów psychologicznych kierowców zawodowych, biorące pod uwagę wskaźniki podatności na dystrakcję i ich zależność od wieku. Wykazano, że z wiekiem maleje szybkość przetwarzania informacji, pojawia się też więcej błędnych decyzji i nieprawidłowości w rozpoznawaniu obiektów. Najsilniejsze obniżenie wyników zaobserwowano w teście wymagającym oceny prędkości i umiejętności antycypowania ruchu obiektów. Generalnie wraz ze wzrostem złożoności zadania wpływ wieku na wskaźniki świadczące o skłonności do rozpraszania w sytuacjach drogowych był większy. Wnioski z analiz pozwalają rekomendować ograniczenie obecności w otoczeniu drogi elementów, takich jak reklamy i inne obiekty mogące powodować rozproszenie użytkowników o osłabionej sprawności procesów uwagi.
The article presents the results of analyzes carried out based on the results of psychological tests for professional drivers, taking into account indicators of susceptibility to distraction and their dependence on age. It has been shown that with age the speed of information processing decreases, there are also more wrong decisions made, and anomalies in recognizing objects. The strongest decrease in performance was observed in the test requiring the assessment of the speed and ability to anticipate the movement of objects. Generally, with increasing complexity of the tasks the effect of age on the markers of inattention (distracting the attention) in the driving situations, was greater. The conclusions of the analyses allow to recommend limiting the presence in the road vicinity of such elements as advertisements and other objects that may cause attention distraction of the road users with the weakened attention processes.
Źródło:
Transport Samochodowy; 2016, 3; 33-40
1731-2795
Pojawia się w:
Transport Samochodowy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mechanism and leaching kinetics of molybdenite concentrate in a hydrogen peroxide-acid system
Autorzy:
Aracena, Alvaro
Azocar, Alan
Ibáñez, Juan Patricio
Jerez, Oscar
Powiązania:
https://bibliotekanauki.pl/articles/110193.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
molybdenite concentrate
hydrogen peroxide
kinetics
mechanism of reaction
Opis:
The mechanism and leaching kinetics of a molybdenite concentrate in a H2O2-H2SO4 system were studied. The experimental work was performed in a batch reactor equipped with a condenser, a mechanical agitator and a temperature control system. The effects of the temperature, H2O2 and H2SO4 concentrations, particle size, liquid/solid ratio and agitation speed on the Mo recovery were investigated. The thermodynamic results showed that the leaching mechanism it was governed by several intermediate reactions; however, the influences of sulfuric acid and passivation were not observed in the reaction. The most predominant experimental result was the maximum Mo recovery of 81.3% by leaching 64 μm particles at 333 K (60 °C) for 5400 s (90 min). The molybdenum recovery was generally enhanced by increasing the H2O2 and H2SO4 concentrations. However, at H2SO4 concentrations higher than 1.0 mol/dm3, the Mo recovery decreased. Although the agitation speed affected the Mo recovery considerably, high recoveries could be still obtained without mixing. The experimental results and XRD analysis confirmed the reaction mechanisms. The leaching kinetics were analyzed using a shrinking core model in which the rate was controlled by diffusion through a porous layer with radius ro. The reaction rate orders were 1.0 and 0.2 for the H2O2 and H2SO4 concentrations, respectively, and the rate was inversely proportional to the square of the initial particle radius. The calculated activation energy was 75.2 kJ/mol in the temperature range of 278-333 K (5-60 °C).
Źródło:
Physicochemical Problems of Mineral Processing; 2019, 55, 1; 140-152
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Response of pea genotypes to seed infection by Ascochyta blight fungi.
Autorzy:
Marcinkowska, Joanna
Boros, Lech
Wawer, Anna
Powiązania:
https://bibliotekanauki.pl/articles/2198959.pdf
Data publikacji:
2009-06-21
Wydawca:
Instytut Hodowli i Aklimatyzacji Roślin
Tematy:
Ascochyta blight
intensity
lines cultivars
occurrence
seeds reaction
Opis:
Seeds collected from 10 genotypes of Pisum sativum of both foliage type, inoculated in field by Mycosphaerella pinodes and Phoma pinodella, were evaluated for incidence of fungi responsible for ascochyta blight. Also seed germination and contamination by other fungi were considered. Surface sterilized seeds were plated on Coon agar medium. A sample contains 50 seeds. Data were taken after 8 days of incubation. Frequency of species occurrence depended not only on characters of genotypes, weather conditions during 1998-2001, but on inoculation treatment. Clear response between genotypes to tested factors was noted. Seeds of normal leaved line 344/87/3 and cv. Rubin were the most inhabited by all fungi, and germinated very poorly. Seeds of eight genotypes, including cvs: Kwestor, Agra, Miko, were less infected and better germinated...
Źródło:
Plant Breeding and Seed Science; 2009, 59; 75-86
1429-3862
2083-599X
Pojawia się w:
Plant Breeding and Seed Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The influence of sulfur addition on the hazard-type reaction of ilmenite ores with sulfuric acid
Autorzy:
Jabłoński, Maciej
Lubkowski, Krzysztof
Tylutka, Sandra
Ściążko, Andrzej
Powiązania:
https://bibliotekanauki.pl/articles/1849314.pdf
Data publikacji:
2021
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
hazard-type reaction
ilmenite
titanium dioxide pigment
sulfur
Opis:
The paper presents results of thermokinetic investigation of the hazard-type reaction of Norwegian and Australian ilmenite ores with sulfuric acid, modified by the addition of elemental sulfur, to increase the process safety in industrial conditions. In the reactions of both ilmenite ores the addition of sulfur caused a reduction of the thermal power generated in the reaction and a decrease in the value of the thermokinetic parameter ΔTmax/Δτ for almost the whole range of initial concentrations of sulfuric acid. It was also found that the addition of sulfur to the reaction did not negatively affect the degree of ilmenite leaching. The interpretation of the obtained thermokinetic curves allowed to determine safe process conditions for both types of titanium raw materials.
Źródło:
Polish Journal of Chemical Technology; 2021, 23, 3; 17-23
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The influence of sulfur addition on the hazard-type reaction of ilmenite ores with sulfuric acid
Autorzy:
Jabłoński, Maciej
Lubkowski, Krzysztof
Tylutka, Sandra
Ściążko, Andrzej
Powiązania:
https://bibliotekanauki.pl/articles/1849319.pdf
Data publikacji:
2021
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
hazard-type reaction
ilmenite
titanium dioxide pigment
sulfur
Opis:
The paper presents results of thermokinetic investigation of the hazard-type reaction of Norwegian and Australian ilmenite ores with sulfuric acid, modified by the addition of elemental sulfur, to increase the process safety in industrial conditions. In the reactions of both ilmenite ores the addition of sulfur caused a reduction of the thermal power generated in the reaction and a decrease in the value of the thermokinetic parameter ΔTmax/Δτ for almost the whole range of initial concentrations of sulfuric acid. It was also found that the addition of sulfur to the reaction did not negatively affect the degree of ilmenite leaching. The interpretation of the obtained thermokinetic curves allowed to determine safe process conditions for both types of titanium raw materials.
Źródło:
Polish Journal of Chemical Technology; 2021, 23, 3; 17-23
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis of the Nickel-Cobalt-Manganese Cathode Material Using Recycled Nickel as Precursors from Secondary Batteries
Autorzy:
Jung, Hang-Chul
Han, Deokhyun
Kim, Dae-Weon
Ahn, Byungmin
Powiązania:
https://bibliotekanauki.pl/articles/2049177.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
secondary battery
nickel
recycling
Taylor reaction
cathode materials
Opis:
As the amount of high-capacity secondary battery waste gradually increased, waste secondary batteries for industry (high-speed train & HEV) were recycled and materialization studies were carried out. The precipitation experiment was carried out with various conditions in the synthesis of LiNi0.6Co0.2Mn0.2O2 material using a Taylor reactor. The raw material used in this study was a leaching solution generated from waste nickel-based batteries. The nickel-cobalt-manganese (NCM) precursor was prepared by the Taylor reaction process. Material analysis indicated that spherical powder was formed, and the particle size of the precursor was decreased as the reaction speed was increased during the preparation of the NCM. The spherical NCM powder having a particle size of 10 μm was synthesized using reaction conditions, stirring speed of 1000 rpm for 24 hours. The NCM precursor prepared by the Taylor reaction was synthesized as a cathode material for the LIB, and then a coin-cell was manufactured to perform the capacity evaluation.
Źródło:
Archives of Metallurgy and Materials; 2021, 66, 4; 987-990
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Novel Process for Recovery of Key Elements from Commercial Cathode Material of End-of-Life Lithium-Ion Battery
Autorzy:
Wang, Jei-Pil
Powiązania:
https://bibliotekanauki.pl/articles/2049270.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
lithium manganese oxide
cathode material
thermal reaction
lithium
Opis:
A novel process to recover lithium and manganese oxides from a cathode material (LiMn2O4) of spent lithium-ion battery was attempted using thermal reaction with hydrogen gas at elevated temperatures. A hydrogen gas as a reducing agent was used with LiMn2O4 powder and it was found that separation of Li2O and MnO was taken place at 1050°C. The powder after thermal process was washed away with distilled water and only lithium was dissolved in the water and manganese oxide powder left behind. It was noted that manganese oxide powder was found to be 98.20 wt.% and the lithium content in the solution was 1,928 ppm, respectively.
Źródło:
Archives of Metallurgy and Materials; 2021, 66, 3; 745-750
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis and Characterization of 1-(1-chlorocyclopropyl)-2-(1,2,4-triazol-1-yl)ethan-1-one
Autorzy:
Ji, H.
Niu, Y.
Liu, D.
Wang, W.
Dai, C.
Powiązania:
https://bibliotekanauki.pl/articles/778677.pdf
Data publikacji:
2017
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
prothioconazole
1,2,4-triazole
N-alkylation reaction
Opis:
A simple and efficient method to prepare 1-(1-chlorocyclopropyl)-2-(1,2,4-triazol-1-yl)ethan-1-one via nucleophilic substitution of 2-chloro-1-(1-chlorocyclopropyl)ethanone and 1,2,4-triazole is described. The title compound is the key intermediate required for the synthesis of prothioconazole, a promising agricultural fungicide. By exploring changes in the reaction time, temperature, ratio of starting reagents, acid binding agent, and the nature of phase transfer catalyst, the reaction conditions could be optimized to afford the desired N-alkylated material in near-quantitative yield. The ultimate yield of the product after recrystallization was 93%, with a purity of 99% based on its characterization by Gas Chromatography-Mass Spectrometer (GC-MS), Fourier Transform infrared spectroscopy (IR), Proton Magnetic Resonance (1H NMR), and Carbon-13 Nuclear Magnetic Resonance (13C NMR). The synthetic process is suitable for industrial application, with the advantages of high yield and facile preparation under mild operating conditions.
Źródło:
Polish Journal of Chemical Technology; 2017, 19, 1; 41-47
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis and Characterization of Si Oxide Coated Nano Ceria by Hydrolysis, and Hydrothermal Treatment at Low Temperature
Autorzy:
Kong, M.
Kim, H. W.
Powiązania:
https://bibliotekanauki.pl/articles/354290.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
nano-particle
water glass
hydro-reaction
coating method
Opis:
The purpose of this work was to the application of Si oxide coatings. This study deals with the preparation of ceria (CeO2) nanoparticles coating with SiO2 by water glass and hydrolysis reaction. First, the low temperature hydro-reactions were carried out at 30~100°C. Second, Silicon oxide-coated Nano compounds were obtained by the catalyzing synthesis. CeO2 Nano-powders have been successfully synthesized by means of the hydrothermal method, in a low temperature range of 100~200°C. In order to investigate the structure and morphology of the Nano-powders, scanning electron microscopy (SEM) and X-ray diffraction (XRD) were employed. The XRD results revealed the amorphous nature of silica nanoparticles. To analyze the quantity and properties of the compounds coated with Si oxide, transmission electron microscopy (TEM) in conjunction with electron dispersive spectroscopy was used. Finally, it is suggested that the simple growth process is more favorable mechanism than the solution/aggregation process.
Źródło:
Archives of Metallurgy and Materials; 2017, 62, 2B; 1125-1129
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mechanism and Synthesis of Yttrium Iron (Y-Fe) Alloy by Low Temperature Process Using Calcium as Reductant
Autorzy:
Ilayaraja, Marimuthu
Berchmans, L. John
Sankaranarayan, Sankara Raman
Powiązania:
https://bibliotekanauki.pl/articles/355144.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Gibbs free energy
reaction kinetics
VSM
XRD
SEM
Opis:
In this paper, study the preparation of Y-Fe alloy by reduction-diffusion process, which is novel technique for producing an alloy from its ores directly at different temperatures. From this work, investigates the particles size and morphology structure of alloy by X-Ray Diffraction (XRD), Energy dispersive-X-ray analyzer (EDAX) and Scanning Electron Microscope (SEM) respectively. Here study the thermodynamics of property of system such as Gibbs free energy and reaction kinetics of system respectively. The Vibrating Sample magnetometer (VSM) is used to study the magnetic properties of alloy such as cocerviety, saturation magnetization and retentivity.
Źródło:
Archives of Metallurgy and Materials; 2019, 64, 4; 1593-1596
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Back-Diffusion In Crystal Growth. Peritectics
Dyfuzja wsteczna we wzroście kryształu. Perytektyki
Autorzy:
Wołczyński, W.
Powiązania:
https://bibliotekanauki.pl/articles/356519.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
microsegregation
redistribution
peritectic reaction
mikrosegregacja
redystrybucja
reakcja perytektyczna
Opis:
A model for the solute micro-segregation/redistribution is delivered. The description is associated with solidification of the peritectic alloys. The peritectic transformation is treated as the phenomenon which modifies the solute redistribution profile resulting from both partitioning and back-diffusion. The relationship allowing for the amount of peritectic phase calculation is also formulated.
Proponowany jest model mikrosegregacji/redystrybucji składnika stopowego. Opis ten dotyczy krystalizacji stopów perytektycznych. Transformacja perytektyczna jest traktowana jako zjawisko, które modyfikuje profil redystrybucji składnika wynikający z rozdziału i dyfuzji wstecznej. Sformułowane jest także równanie, które pozwala wyznaczyć ilość fazy perytektycznej.
Źródło:
Archives of Metallurgy and Materials; 2015, 60, 3; 2409-2414
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Deep Roots of Fiscal Behavior
Autorzy:
Cevik, Serhan
Teksoz, Katerina
Powiązania:
https://bibliotekanauki.pl/articles/565644.pdf
Data publikacji:
2014
Wydawca:
Uniwersytet Warszawski. Wydawnictwo Naukowe Wydziału Zarządzania
Tematy:
Fiscal policy
fiscal reaction functions
fiscal policy volatility
Opis:
This paper investigates the determinants of fiscal policy behavior and its time-varying volatility, using panel data for a broad set of advanced and emerging market economies during the period 1990–2012. The empirical results show that discretionary fiscal policy is influenced by policy inertia, the level of public debt, and the output gap in both advanced and emerging-market economies. In addition, the paper finds that macro-financial factors (such as real exchange rate, financial development, interest rates, asset prices, and natural resource rents) and demographic and institutional factors (such as the old-age dependency ratio, the quality of institutions, and policy anchors such as fiscal rules and IMF-supported stabilization programs) tend to have a significant effect on fiscal policy behavior. The results also indicate that higher government debt leads to more volatile fiscal behavior, while fiscal rules and higher institutional quality reduce the volatility of fiscal policy over time.
Źródło:
Journal of Banking and Financial Economics; 2014, 2(2); 5-33
2353-6845
Pojawia się w:
Journal of Banking and Financial Economics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of a hydrolysed salmon and pea hypoallergenic diet application in dogs and cats with cutaneous adverse food reaction
Autorzy:
Szczepanik, M.P.
Gołyński, M.
Wilkołek, P.
Kalisz, G.
Powiązania:
https://bibliotekanauki.pl/articles/16539080.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
cats
cutaneous adverse food reaction
dogs
hypoallergenic diet
Opis:
Cutaneous adverse food reaction (CAFR) is a common disease, affecting about 1-2% of dogs and cats. Diagnosis of the CAFR is made through elimination diet coupled with diet challenge, as methods like skin tests, patch tests, basophil degranulation tests and assessment of IgG and IgE serum levels are not sensitive enough. A partially hydrolysed salmon and pea hypoallergenic diet was evaluated in the diagnosis and treatment of CAFR in dogs and cats. The diet was used in the treatment of 13 dogs and 12 cats for 10 weeks. The Pruritus Visual Analog Scale (PVAS; dogs and cats), Canine Atopic Dermatitis Extent and Severity Index (CADESI-04; dogs) and the Scoring Feline Allergic Dermatitis (SCORFAD; cats) were used for effectiveness evaluation. In dogs, a significant decrease was reported in both CADESI-04 (from 17.3±7.5 to 10.15±7.4; p=0.028) and PVAS (from 7±1.3 to 4.76±1.8; p=0.003) after four weeks of treatment. Also in cats, both the PVAS (from 6.75±1.8 to 4±2.3; p=0.006) and SCORFAD (from 4.16±1.9 to 2.58±1.2; p=0.029) decreased significantly after four weeks. After eight weeks, a significant improvement was observed in almost all the animals. Evaluated diet was useful in the treatment of the CAFR in dogs and cats.
Źródło:
Polish Journal of Veterinary Sciences; 2022, 25, 1; 67-73
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Framework for topographic mesh generation and its application to the pollution simulations in Kraków area
Framework do generacji topograficznych siatek obliczeniowych i jego zastosowanie do symulacji zanieczyszczeń w okolicy Krakowa
Autorzy:
Podsiadło, Krzysztof
Serra, Albert Oliver
Paszyński, Maciej
Powiązania:
https://bibliotekanauki.pl/articles/29520323.pdf
Data publikacji:
2019
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
pollution simulation
Kraków
advection-diffusion-reaction
mesh generation
Opis:
Air pollution is receiving a lot of interest nowadays. It is visible especially in the Kraków area, as this is one of the most polluted cities in Europe. People living there are more and more aware of the problem, what causes raising of various movements and NGOs that are trying to improve air quality. Unfortunately, this is not as simple as people usually think: air pollution grows because of multiple factors including traffic, climate, heating of buildings in winter, city’s architecture, etc. In this paper, we simulate and predict pollution with high resolution, as air quality can vary significantly over a distance of even a few hundreds of meters. Air quality simulation is a multidisplinary endeavor, comprising physical models (meteorological and chemistry) as well as numerical methods (geometry discretization, time and space discretization, etc.). It has been found that there is no proper method for automatic terrain mesh generation, so an algorithm for doing it is presented in this document as its significant part.
Problem zanieczyszczenia powietrza staje się coraz bardziej zauważalny w czasach dzisiejszych. Dotyczy to szczególnie okolic Krakowa, będącego jednym z najbardziej zanieczyszczonych miast w Europie. Ludzie mieszkający w rejonie Krakowa stali się bardziej świadomi problemu zanieczyszczeń, co zmotywowało do powstawania różnych organizacji publicznych oraz zainicjowało różne działania władz na szczeblu lokalnym oraz globalnym w celu polepszenia jakości powietrza. Niestety problem powstawania i propagacji zanieczyszczeń jest bardzo skomplikowany, i łączy w sobie wiele czynników takich jak transport miejski, lokalny klimat, problem ogrzewania budynków w okresie zimowym, struktura architektury miejskiej, itp. W artykule tym zajmujemy się symulacjami i predykcją zanieczyszczeń z wysoką rozdzielczością, z uwagi na fakt, iż jakość powietrza może się istotnie zmieniać z jednego miejsca do drugiego na odległości kilkuset metrów. Symulacje zanieczyszczeń to zadanie wielodyscyplinarne, łączące ze sobą modele fizyczne (meteorologiczne i chemiczne), oraz modele numeryczne (dyskretyzacja geometrii, dyskretyzacja czasowoprzestrzenna). W szczególności zajęliśmy się skonstruowaniem nowego algorytmu automatycznej generacji topograficznych siatek obliczeniowych i jego wykorzystaniem w zagadnieniach symulacji zanieczyszczeń.
Źródło:
Computer Methods in Materials Science; 2019, 19, 1; 21-28
2720-4081
2720-3948
Pojawia się w:
Computer Methods in Materials Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
LiOO.H2O as a catalyst for Knoevenagel and Gewald reactions
Autorzy:
Gouda, M. A.
Powiązania:
https://bibliotekanauki.pl/articles/778071.pdf
Data publikacji:
2010
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
Malononitryl
Cykloheksan
Cyclohexanone
LiOO.H2O
reakcja Knoevenagel
reakcja Gewalda
Malononitrile
Ethylcyanoacetate
cyclohexanone
Knoevenagel reaction
Gewald reaction
Opis:
Commercial available lithium hydroxide monohydrate LiOH.H 2O was found to be a novel 'dual activation' catalyst for tandem cross Knoevenagel condensation between malononitrile or ethylcyanoacetate and aromatic aldehydes leading to an efficient and easy synthesis of the corresponding arylidenes at room temperature in a short reaction time. In the case of salicyaldehyde the reaction lead to the formation of 3-substituted coumarins. The high efficacy, cheapness and easy availability of LiOH.H2O prompted us to investigate its validity as a basic catalyst for Gewald reaction.
Źródło:
Polish Journal of Chemical Technology; 2010, 12, 4; 31-35
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Deterministic models and stochastic simulations in multiple reaction models in systems biology
Autorzy:
Laroch, P.
Puszynski, K.
Polanski, A.
Powiązania:
https://bibliotekanauki.pl/articles/80910.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
deterministic model
stochastic simulation
multiple reaction model
stochastic approach
modelling
biomolecular reaction
system biology
computational analysis
algorithm
living organism
biomolecule
Źródło:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology; 2011, 92, 3
0860-7796
Pojawia się w:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparative behaviour analysis of some colubrids with reference to suitability of captive bred snakes for reintroduction to natural habitat
Porównawcza analiza zachowań węży z rodziny Colubridae pod kątem przydatności osobników hodowanych w niewoli do reintrodukcji do środowiska naturalnego
Autorzy:
Zyczynski, A.
Nowak, Z.
Powiązania:
https://bibliotekanauki.pl/articles/2732.pdf
Data publikacji:
2013
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Wydawnictwo Szkoły Głównej Gospodarstwa Wiejskiego w Warszawie
Tematy:
comparative analysis
behavioural analysis
colubrid
Colubridae
suitability
snake
reintroduction
natural habitat
captive breeding
conservation
antagonistic reaction
feeding reaction
Pantherophis
Lampropeltis
Opis:
A sample of newly hatched American colubrids, divided according to their level of domestication, understood herewith as the generation history in captivity, was tested in an open field test (OFT) for degree of activity and confidence in open terrain and in confrontation with individuals of such species as Pantherophis guttatus and Lampropeltis getula splendida as well as L. g. californiae, in order to compare their antagonistic and feeding behaviour reactions. The cluster comparison of defence reactions revealed no effect of domestication (many generation in captivity) in the face of potential danger. Even albino phase Kingsnakes, considered to be the form of this species most affected by captivity (altered genome), maintained their natural feeding response. The degree of activity in OFT conditions was seen to decrease with the snakes' age. Thus it was demonstrated that captive specimens bred in terrariums may be considered a gene bank for ex situ conservation strategy. However it is recommended that specimens as young as possible should be used in reintroduction to natural habitat, as these will respond most faithfully to the pressure of natural selection, based on their behavioural variation not supressed by apathy caused by captivity.
Porównawcza analiza zachowań węży z rodziny Colubridae pod kątem przydatności osobników hodowanych w niewoli do rein-trodukcji do środowiska naturalnego. W modelowym doświadczeniu przetestowano amerykańskie węże z rodziny Colubridae podzielone według stopnia udomowienia (pokoleniowego stażu w warunkach niewoli). Zwierzęta zostały poddane testowi otwartego pola (OFT), sprawdzającego ich aktywność i odwagę na otwartej przestrzeni oraz konfrontacji z innym wężem zbożowym Pantherophis guttatus oraz lancetogłowem królewskim Lampropeltis getula splendida i dodatkowo L.g. californiae, formą albinotyczną. Test OFT wykazał ujemny wpływ wieku na aktywność terraryjnych zwierząt a konfrontacje z probantami nie ujawniły wpływu udomowienia na reakcje obronne (klasterowa analiza skupień). Nawet u albinotycznych lancetogłowów, uznanych za najbardziej udomowioną formę (zubożały, wsobny genotyp) utrzymywanych od pokoleń na nie- naturalnej diecie, wystąpiły normalne reakcje drapieżnicze. Stwierdzono zatem przydatność populacji terraryjnej jako ewentualnego banku genów dla strategii ochronnej ex situ, przy zaleceniu używania do reintrodukcji materiału możliwie młodego, najwierniej reagującego na presję selekcji naturalnej, wymierzonej w wachlarz reakcji niestłumionych warunkami niewoli.
Źródło:
Annals of Warsaw University of Life Sciences - SGGW. Animal Science; 2013, 52
1898-8830
Pojawia się w:
Annals of Warsaw University of Life Sciences - SGGW. Animal Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Eutectoid Reaction Ar1 of Cast Iron GJS-400-15 in Isothermal Conditions
Autorzy:
Szykowny, T.
Romanowski, Ł.
Giętka, T.
Powiązania:
https://bibliotekanauki.pl/articles/381418.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
heat treatment
spheroidal cast iron
eutectoid reaction
austenitizing temperature
kinetics of eutectoid reaction
obróbka cieplna
żeliwo sferoidalne
reakcja eutektoidalna
Opis:
This scientific paper presents the research on influence of austenitizing temperature on kinetics and evolution of the spheroidal plain cast iron during eutectoid reaction in isothermal conditions. The cast iron has been austenitized in temperatures of 900, 960 or 1020°C. Therewere two temperature values of isothermal holding taken into consideration: 760 or 820°C. The order of creation of reaction products and their morphology have been analyzed. The particular attention has been paid to the initial stage of transformation. The qualitative research has been executed using the transmission electron microscope (TEM), as well as quantitative research (LM). The influence of austenitizing temperature has also been determined on transformation kinetics and structural composition. It was found that the increase of austenitizing temperature is conductive to the initial release of structures by metastable system. A reduction of time was observed of the initial stage of transformation at temperature close to Ar12 with its simultaneous elongation at temperature close to Ar11, with an increase of austenitizing temperature. The dependences obtained by the metallographic method confirm the prior results of dilatometric research of eutectoid reaction.
Źródło:
Archives of Foundry Engineering; 2014, 14, 3; 93-98
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Acute hypersensitivity reaction following intravenous ferric carboxymaltose injection for iron deficiency anaemia: a case report
Autorzy:
Kumar, Neeraj
Gautam, Preeti Bala
Ahmad, Sarfaraz
Qutub, Danish
Prasad, Indira
Powiązania:
https://bibliotekanauki.pl/articles/29432056.pdf
Data publikacji:
2023
Wydawca:
Towarzystwo Pomocy Doraźnej
Tematy:
Ferric carboxy maltose
hypersensitivity reaction
intensive care unit
Opis:
Ferric carboxymaltose (FCM) is a non-dextran iron preparation used for intravenous treatment of iron deficiency anaemia (IDA) in adult patients with intolerance or poor response to oral iron therapy. Acute hypersensitivity reactions (HSRs) during iron infusions are very rare but can be life-threatening even after receiving a prior test dose. Here, we report a case of 42 years old female patient who underwent total laparoscopic hysterectomy with bilateral salpingo-oophorectomy. On the next postoperative day she received an injection of ferric carboxy maltose. She was diagnosed with IDA. She presented with the picture of an adverse drug reaction due to injection FCM. She was managed with oxygen, vasopressors, antihistaminics, intravenous fluids and, corticosteroids. She recovered well within 24 hours of intensive care unit admission following this adverse drug reaction. So, careful and precise observation is required in management of adverse reaction following ferric carboxymaltose and prompt recognition and treatment based on severity is warranted.
Źródło:
Critical Care Innovations; 2023, 6, 1; 41-45
2545-2533
Pojawia się w:
Critical Care Innovations
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of Process Parameters on Ceroxide Formation in Low-Carbon Steels
Autorzy:
Vaucheret, A.
Nicolini, C.
Carton, J.-F.
Jacquet, P.
Powiązania:
https://bibliotekanauki.pl/articles/106937.pdf
Data publikacji:
2017
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
ceroxide
low carbon steel
mold/metal reaction
deoxidation
Opis:
Ceroxides are surface defects caused by a mold-metal reaction during the casting process of steels. This type of defect may affect a large area, but it is located only on the skin of the parts. It does not affect the core of the parts nor its mechanical properties. Nevertheless, ceroxides induce a lack of material on the surface, forming a kind of crater and needing complementary surfacing. The defect is also composed by several non-metallic inclusions containing Al, Mg, Si and O. An EDX analysis by mapping show these elements involved in the mold-metal reaction. The presence of these oxides could confirm the hypothesis of the deoxidizer reoxidation found in the bibliography. To better understand the specific conditions of ceroxide formation, the first step was to find of way to generate systematically this defect at each casting. Two patterns with different filling rate were designed, simulated on Quikcast and tested. The pattern with turbulent filling rate allowed the formation of ceroxide at each casting and so was used during this study. This result shows that the filling rate of the mold could be considered as a first order parameter in ceroxide formation. Then, a specific experimental set up was designed to characterize this defect. The analysis of the defect was done for sizing it: surface and depth. Finally, some key parameters on defect formation were determined like the nature of deoxidizer or the amount of oxygen in the mould. Some laboratory tests were lead to show the influence of these parameters by characterization of the casted parts in comparison with a reference sample. This study allowed us to find process parameters responsive of ceroxide formation and to propose some way of improvement to reduce the size and the occurrence of ceroxides.
Źródło:
Journal of Casting & Materials Engineering; 2017, 1, 4; 90-96
2543-9901
Pojawia się w:
Journal of Casting & Materials Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
CFD analysis of mixing intensity in jet stirred reactors
Autorzy:
Gil, I.
Mocek, P.
Powiązania:
https://bibliotekanauki.pl/articles/185797.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
kinetyka
CFD
jet stirred reactor
kinetic
reaction design
Opis:
The homogeneous stirred reactor designed for kinetic studies of the combustion of hydrocarbons with intensive internal recirculation in high temperature combustion chamber is described. The originality of our reactor lies in its construction which allows to intensively mix fuel and flue gases, measure gas temperature as well as obtain samples which can be used to investigate diffusion flames. The cylindrical construction enables to use the reactor in laboratory cylindrical electrically heated ovens. The CFD analysis of the reactors, the mixing parameters (turbulent Peclet number and mixing level) and the volume average temperature in the reactors were elaborated on the basis of the typical dimensions of classical reactors to kinetics research as well as the own reactor design. The results of the analysis allow to reveal advantages of our construction.
Źródło:
Chemical and Process Engineering; 2012, 33, 3; 397-410
0208-6425
2300-1925
Pojawia się w:
Chemical and Process Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Molecular diagnostics of Sarcocystis spp. infections
Autorzy:
Stojecki, K.
Karamon, J.
Sroka, J.
Cencek, T.
Powiązania:
https://bibliotekanauki.pl/articles/2088002.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
molecular diagnostics
Sarcocystis
infection
sarcocystosis
polymerase chain reaction
Opis:
Protozoa of the genus Sarcocystis (phylum Apicomplexa, family Sarcocystidae) is one of the most common parasites affecting animals. Interspecies diagnostic of Sarcocystis genus was based on electron microscopy for many years. Because of absence of visible differences between species with reachable magnifications, light microscopy is useless. In many cases serological diagnostic method have lack of sensitivity. A variety of molecular methods have been developed and used to detect and identify Sarcocystis spp. and to assess the genetic diversity among this protozoan from different population/hosts. Nowadays, molecular diagnostic is the common, time/cost effective method used all over the world to interspecies differentiation.
Źródło:
Polish Journal of Veterinary Sciences; 2012, 15, 3
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Impact of agricultural use on chosen soil properties
Autorzy:
Braun, Barbara
Powiązania:
https://bibliotekanauki.pl/articles/2029783.pdf
Data publikacji:
2008-06-01
Wydawca:
Uniwersytet Warszawski. Wydział Geografii i Studiów Regionalnych
Tematy:
agricultural use
soil reaction
bulk density
organic matter
Opis:
Agricultural use may change soil. These changes may be observed by examining certain soil properties. In numerous cases of agricultural use, soil compaction may be observed at the depth of 25-35 cm. After many years of use, this may lead to the creation of a plough sole. On arable grounds, which are generally fertilized by minerals, a decrease in organic matter content and soil acidification are frequently observed. Each human activity leads to changes in the natural environment. In the case of agricultural use, the greatest changes take place in soil. Mechanization in agriculture and the wish to produce ever-greater amounts of crops influence changes in some soil properties. In a short time, changes in soil reaction, organic matter content or creation of a plough sole at the depth of 25-35 cm may observed.
Źródło:
Miscellanea Geographica. Regional Studies on Development; 2008, 13; 153-162
0867-6046
2084-6118
Pojawia się w:
Miscellanea Geographica. Regional Studies on Development
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Proteus mirabilis RMS 203 as a new representative of the O13 Proteus serogroup
Autorzy:
Palusiak, Agata
Siwińska, Małgorzata
Zabłotni, Agnieszka
Powiązania:
https://bibliotekanauki.pl/articles/1038887.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
cross-reaction
lipopolysaccharide
O-polysaccharide
O serogroup
Proteus
Opis:
The unique feature of some Proteus O-polysaccharides is occurrence of an amide of galacturonic acid with Nε-[(S/R)-1-Carboxyethyl]-l-lysine, GalA6(2S,8S/R-AlaLys). The results of the serological studies presented here, with reference to known O-antigens structures suggest that GalA6(2S,8S/R-AlaLys) or 2S,8R-AlaLys contribute to cross-reactions of O13 Proteus antisera, and Proteeae LPSs. It was also revealed that the Proteus mirabilis RMS 203 strain can be classified into the O13 serogroup, represented so far by two strains: Proteus mirabilis 26/57 and Proteus vulgaris 8344. The O13 LPS is a serologically important antigen with a fragment common to LPSs of different species in the Proteeae tribe.
Źródło:
Acta Biochimica Polonica; 2015, 62, 4; 691-695
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Assessment of landslide hazard from tree-ring eccentricity and from compression wood : a comparison
Autorzy:
Łuszczyńska, Katarzyna
Malik, Ireneusz
Wistuba, Małgorzata
Krąpiec, Marek
Powiązania:
https://bibliotekanauki.pl/articles/2058669.pdf
Data publikacji:
2019
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
eccentric growth
reaction wood
landslide activity
Western Carpathians
Opis:
We have compared maps of landslide activity and hazard, developed with the use of two different dendrochronological indicators: tree-ring eccentricity and reaction (compression) wood. The maps were prepared based on 125 Norway spruce (Picea abies L. Karst.) trees growing at 44 sampling points, distributed over an area of 3.75 km2. In general, the two maps show similar patterns of landslide activity. However, tree-ring eccentricity yielded a greater number of dated events (246) compared to compression wood (129). Besides the differences in the absolute values of dating results, the general landslide activity and hazard zonation based on both disturbances are similar. Both growth disturbances develop as a result of stem tilting. Eccentricity develops after slight tilting, while compression wood is developed when tilting is more significant. Because of the differences in the strength of disturbing factors, which cause the development of compression wood and growth eccentricity, the best approach would be to combine the results of dating obtained from the two methods. The dendrochronological analysis of tree growth disturbances (eccentric growth and compression wood) is a promising approach for determining landslide hazards in forested mountain areas and can be applied in spatial management.
Źródło:
Geological Quarterly; 2019, 63, 2; 296--301
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An alternative scheme for determination of joint reaction forces in human multibody models
Alternatywny sposób wyznaczania reakcji w stawach wieloczłonowych modeli ciała człowieka
Autorzy:
Blajer, W.
Czaplicki, A.
Powiązania:
https://bibliotekanauki.pl/articles/279332.pdf
Data publikacji:
2005
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
human body modeling
dynamic analysis
joint reaction forces
Opis:
Multibody models are commonly used in the analysis of human movements. The dynamic formulations often use minimal sets of generalized coordinates, and joint reactions (non-working reactions of model-intrinsic constraints) are excluded from evidence. A separate modeling effort is then required to determine joint reactions, and the arising numerical procedures are computationally arduous. In this paper, a novel efficient approach to the determination of joint reactions is developed, which naturally assists the minimal-form formulations of human body dynamics. The proposed scheme does not involve matrix inversion, and as such it is well suited for both symbolic manipulations and computer implementations. The method is illustrated with a seven-segment planar model of a human body. Some results from the inverse dynamics simulation of somersaults on a trampoline are reported.
Wieloczłonowe modele ciała człowieka są powszechnie wykorzystywane do analizy czynności motorycznych. Dla sformułowań dynamiki tych modeli stosowane są zwykle niezależne współrzędne uogólnione, co powoduje, że reakcje w połączeniach (idealne reakcje więzów wewnętrznych) są eliminowane na wstępnym etapie modelowania. Dla ich określenia wymagane są dodatkowe procedury modelowania matematycznego, a generowane tą drogą zależności charakteryzują się niską efektywnością numeryczną. W niniejszej pracy proponowane jest nieco inne podejście do wyznaczania reakcji w stawach, w sposób naturalny skojarzone z minimalno-wymiarowym formułowaniem dynamiki wieloczłonowych modeli ciała człowieka. Proponowane sformułowania nic wymagają odwracania macierzy, są tym samym efektywne zarówno dla wyprowadzeń symbolicznych, jak i zastosowań numerycznych. Metoda zilustrowana jest za pomocą siedmioczłonowego płaskiego modelu ciała człowieka. Prezentowane są wybrane wyniki obliczeń numerycznych odnoszące się do symulacji dynamicznej odwrotnej sportowca wykonującego salto na trampolinie.
Źródło:
Journal of Theoretical and Applied Mechanics; 2005, 43, 4; 813-824
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of the scenario complexity and the lighting conditions on the driver behaviour in a car-following situation
Autorzy:
Jurecki, Rafał
Powiązania:
https://bibliotekanauki.pl/articles/263747.pdf
Data publikacji:
2019
Wydawca:
Sieć Badawcza Łukasiewicz. Przemysłowy Instytut Motoryzacji
Tematy:
simulator
car-following situation
driver behaviour
reaction time
Opis:
The aim of this study was to analyse the driver behaviour in simple and complex car-following situations under day- and night-time lighting conditions (four scenarios). Nearly 70 drivers participated in the tests, each taking several trials, during which they were exposed to randomly selected situations. The tests involved driving along a two-lane motorway with a vehicle in front and responding to its sudden braking. Different distances between the vehicles were simulated. The scenarios varied in complexity ranging from none to some vehicles around the subject vehicle. The study involved measuring different reaction times, i.e. the time to release the accelerator pedal, the time to apply the brake pedal and the time to start steering, to find out how the particular emergency manoeuvres contribute to the occurrence of collisions in the four scenarios. The results show that both the complexity of a road situation as well as the lighting conditions determine the type of emergency manoeuvre undertaken and the time of the driver reaction.
Źródło:
Archiwum Motoryzacji; 2019, 83, 1; 151-173
1234-754X
2084-476X
Pojawia się w:
Archiwum Motoryzacji
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
XAFS in the tracking of reactions in aqueous solution: a case of redox reaction between [AuCl4]- complex ions and ethanol
Metoda XAFS w badaniach reakcji zachodzących w roztworach wodnych: przykład reakcji redoks pomiędzy jonami kompleksowymi [AuCl4]- i alkoholem etylowym
Autorzy:
Pacławski, K.
Sikora, M.
Powiązania:
https://bibliotekanauki.pl/articles/355830.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
XAFS
XANES
redox reaction
gold complex ions
ethanol
Opis:
In this work the potential application of synchrotron radiation in the studies of reaction kinetics in aqueous phase were presented. After short introduction describing principles of technique and potential application of XAFS for the structural studies of reacting species, the experimental results of kinetic measurements of reaction between gold(III) chloride complex ions and ethanol were presented. Analyzing the changes of absorption intensity in the XANES spectra registered at Au-L &sub3; edge during the reaction, the change of the valence state of Au central atom (form 3+to 0) of reacting complex ion was determined. Moreover, empirical XANES data gave the chance to register the kinetic curve and to determine the rate constant of the studied reaction. It was found that reaction is relatively slow (second-order rate constant k = 3.66 · 10 &sup-5; M ;sup-1;s) and lead to the gold metallic phase formation in the system. Applying the continuous-flow method, within the first 600 ms of reaction the changes in XANES spectra were registered. From the obtained results, supported with numerical calculations, two intermediate forms of adducts appearing prior the electron transfer were suggested. It was concluded that when the classic methods, e.g. UV-Vis spectrophotometry, cannot be applied to studies of kinetics of reactions in aqueous solution, the XAFS technique can be a valuable and substitutive (or supplementary) tool for such measurements.
W pracy przedstawiono potencjalne możliwości zastosowania promieniowania synchrotronowego w badaniach nad kinetyka reakcji przebiegających w roztworach wodnych. We wstępie, omówiono podstawy techniki rentgenowskiej analizy struktury nadsubtelnej (XAFS) i jej możliwości zastosowania w badaniach strukturalnych związków chemicznych w fazie ciekłej. Zaprezentowano również dane eksperymentalne z pomiarów XAFS dotyczące kinetyki reakcji pomiędzy chlorkowymi kompleksami złota(III) i alkoholem etylowym. Z analizy zmian intensywności absorpcji widm XANES rejestrowanych przy krawędzi L &sub3; złota określono zmianę stopnia utlenienia atomu centralnego Au (z 3+ do 0) reagującego kompleksu. Ponadto, dane empiryczne pozwoliły na wyznaczenie krzywej kinetycznej oraz określenie drugorzędowej wartości stałej szybkości reakcji (k = 3.66 ·10 &sup-5; M &sup-1;s). W wyniku analizy widm XANES potwierdzono powstawanie faza metalicznej złota w układzie. Stosując metodę ciągłego przepływu reagentów, zarejestrowano zmiany w widmie XANES w ciągu 600 ms od rozpoczęcia reakcji.Na podstawie zarejestrowanych widm oraz przeprowadzonych obliczeń numerycznych zasugerowano dwie możliwe struktury adduktu tworzącego się przed właściwym transferem elektronu w reakcji redoks. Z przeprowadzonych eksperymentów wynika, ze w układach, w których nie jest możliwe stosowanie spektrofotometrii UV-Vis, metoda XAFS może być zastępczym i obiecującym narzędziem do badań kinetyki reakcji.
Źródło:
Archives of Metallurgy and Materials; 2012, 57, 4; 1011-1020
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparative study of chemical synthesis of dihydropyrimidine (DHPMS) derivatives by Biginelli Reaction using microwave irradiation and conventional method
Autorzy:
Sonawane, R.P.
Powiązania:
https://bibliotekanauki.pl/articles/411784.pdf
Data publikacji:
2013
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
dihydropyrimidine derivatives
Biginelli reaction
microwave irradiation
conventional method
Opis:
The majority of the drugs on the market today are entirely chemically synthesized in the laboratory. Several scientists had synthesized dihydropyrimidine (DHPMs) derivatives showing a wide spectrum of biological actions as antibacterials, antivirals as well as antitumor agents. This activity is principally due to presence of steriogenic carbon C4 in their structure. The current investigation is comparative study of chemically synthesis of two DHPMs derivatives by Biginelli Reaction using microwave irradiation and conventional method. The synthesis of DHPMs derivative involves a multicomponent reaction (aldehyde derivative, urea /thiourea and 1,3-dicarbonyl compounds) in presence of HCl / NH4Cl as a catalyst. Two derivative viz. 3,4-dihydropyrimidin-2-(1H)-ones and 3,4-dihydropyrimidin-2-(1H)-thiones were synthesized and characterized using IR. The melting points were obtained are 203 °C and 211 °C respectively. Microwave irradiation was easy and gave more yield than conventional method. This study will help to develop easy protocol for the synthesis of many more DHPMs derivative with high yield.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2013, 5; 7-11
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł

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