Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "reaction;" wg kryterium: Wszystkie pola


Tytuł:
Use of isoperibolic reaction calorimeter for the study of reaction kinetics of acetic anhydride hydrolysis reaction: Effect of acetic anhydride and water ratio
Autorzy:
Kumar, Rajendra
Tiwari, Anurag Kumar
Powiązania:
https://bibliotekanauki.pl/articles/2173434.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
acetic anhydride
water
reaction calorimeter
hydrolysis
kinetics
bezwodnik octowy
woda
kalorymetr reakcyjny
hydroliza
kinetyka
Opis:
Reaction kinetics of acetic anhydride hydrolysis reaction is being studied at a fixed reaction temperature and ambient pressure using an isoperibolic reaction calorimeter. Temperature versus time data along with heat and mass balance is used to determine the kinetics parameters i.e. activation energy and Arrhenius coefficient. It has been studied with the varying volumetric ratio of acetic anhydride and water; and kinetics parameters were compared and plotted for each ratio. Such a study has not been done previously to determine the kinetics dependency on varying the acetic anhydride water ratio. As the acetic anhydride hydrolysis reaction is exothermic in nature, the present study will help to decide the safe and suitable operating conditions such as concentration and temperature for conducting this reaction at plant scale. The kinetic data presented can be used further for the mathematical modeling and simulation of such exothermic hydrolysis reactions.
Źródło:
Chemical and Process Engineering; 2022, 43, 2; 255--264
0208-6425
2300-1925
Pojawia się w:
Chemical and Process Engineering
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:
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:
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:
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:
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:
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 fertilizer on soil reaction
Autorzy:
Skrastina, L.
Vucans, R.
Powiązania:
https://bibliotekanauki.pl/articles/803163.pdf
Data publikacji:
1998
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Wydawnictwo Szkoły Głównej Gospodarstwa Wiejskiego w Warszawie
Tematy:
fertilizer effect
soil reaction
Lithuania
acidification
soil composition
fertilization
Opis:
The aim of study was to determine the influence of growing fertilizer rates on soil reaction. Soil samples were taken from experimental plots, where different amounts of NPK fertilizers were applied for perennial grasses within 6 years (1986 - 1992). The experimental design was 12 treatments in 4 replications, and established in sod-gleysolic loamy sand. Potential acidification of soil as a result of fertilization was calculated based on CaCO₃ balance and obtained results validated with the analytical tests of topsoil (0 - 20 cm) and subsoil (20 - 40 cm) reaction before and after experiment. Obtained results showed low performance of data obtained by calculation CaCO₃ balance, thereby using only CaCO₃ balance, it is risky to forecast soil acidification. In spite ofthat the used fertilizer rates changed in the widely ranges between treatments (N₀P₀K₀ - N₃₀₀P₁₂₀K₂₄₀), fertilization had not significant influence on soil reaction.
Źródło:
Zeszyty Problemowe Postępów Nauk Rolniczych; 1998, 456
0084-5477
Pojawia się w:
Zeszyty Problemowe Postępów Nauk Rolniczych
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:
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:
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:
Thermokinetic analysis of vegetable oil oxidation as an autocatalytic reaction
Autorzy:
Kowalski, B
Powiązania:
https://bibliotekanauki.pl/articles/1371362.pdf
Data publikacji:
1992
Wydawca:
Instytut Rozrodu Zwierząt i Badań Żywności Polskiej Akademii Nauk w Olsztynie
Tematy:
oxidation
vegetable oil
kinetics
autocatalytic reaction
sunflower oil
edible oil
Źródło:
Polish Journal of Food and Nutrition Sciences; 1992, 01, 2; 51-60
1230-0322
2083-6007
Pojawia się w:
Polish Journal of Food and Nutrition Sciences
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:
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:
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:
Differential quadrature methodfor some diffusion-reaction problems
Autorzy:
Szukiewicz, Mirosław K.
Powiązania:
https://bibliotekanauki.pl/articles/184877.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
numerical algorithm
boundary value problem
reaction-diffusion equation
algorytm numeryczny
wartość graniczna
równanie dyfuzji reakcyjnej
Opis:
In the paper, differential quadrature method (DQM) is used to find numerical solutions of reaction-diffusion equations with different boundary conditions. The DQM-method changes the reaction-diffusion equation (ordinary differential equation) into a system of algebraic equations. The obtainedsystem is solved using built-in procedures of Maple®(Computer Algebra System-type program).Calculations were performed with Maple®program. The test problems include reaction-diffusionequation applied in heterogeneous catalysis. The method can be employed even in relatively hard tasks(e.g. ill-conditioned, free boundary problems).
Źródło:
Chemical and Process Engineering; 2020, 41, 1; 3-11
0208-6425
2300-1925
Pojawia się w:
Chemical and Process Engineering
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:
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:
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:
Biochemical reaction systems – system theory and decomposition
Autorzy:
Nemcová, J.
van Schuppen, J. H.
Powiązania:
https://bibliotekanauki.pl/articles/205629.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
biochemical reaction systems
rational systems
realization
decomposition
interconnection
algebra of positive real polynomials
Opis:
Biochemical reaction networks may be modeled as biochemical reaction systems consisting of differential equations with rational functions. Biochemical reaction systems are defined as rational positive dynamic systems with inputs and outputs, and illustrated by examples. This formulation makes available the results from algebraic system theory for rational systems and a relation with computer algebra. It is shown how to decompose networks into subsystems and how to relate them to graphs. The realization problem for this class of systems is briefly discussed. Finally, control problems for biochemical reaction networks are formulated.
Źródło:
Control and Cybernetics; 2013, 42, 1; 183-215
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
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:
Mathematical Modeling of the Bicycle Robot with the Reaction Wheel
Autorzy:
Owczarkowski, A.
Kozierski, P.
Lis, M.
Powiązania:
https://bibliotekanauki.pl/articles/385070.pdf
Data publikacji:
2015
Wydawca:
Sieć Badawcza Łukasiewicz - Przemysłowy Instytut Automatyki i Pomiarów
Tematy:
inertia wheel pendulum
reaction wheel
bicycle robot
dynamic model
Opis:
The article presents the influence of the reaction wheels on the stability of the bicycle robot. The precise mathematical model is presented. The robot is treated as an inverted pendulum with rigid body physical nature. The mathematical analysis can be useful to develop con- trol techniques, to make many computer simulations, to check how the system will behave in reality.
Źródło:
Journal of Automation Mobile Robotics and Intelligent Systems; 2015, 9, 3; 3-8
1897-8649
2080-2145
Pojawia się w:
Journal of Automation Mobile Robotics and Intelligent Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Behaviour of global solutions for a system of reaction-diffusion equations from combustion theory
Autorzy:
Badraoui, Salah
Powiązania:
https://bibliotekanauki.pl/articles/1338841.pdf
Data publikacji:
1999
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
global existence
boundedness
reaction-diffusion equations
large time behaviour
Opis:
We are concerned with the boundedness and large time behaviour of the solution for a system of reaction-diffusion equations modelling complex consecutive reactions on a bounded domain under homogeneous Neumann boundary conditions. Using the techniques of E. Conway, D. Hoff and J. Smoller [3] we also show that the bounded solution converges to a constant function as t → ∞. Finally, we investigate the rate of this convergence.
Źródło:
Applicationes Mathematicae; 1999, 26, 2; 133-150
1233-7234
Pojawia się w:
Applicationes Mathematicae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Remediation of $CO_2$ in Boudouard’s reaction as an example of reversible chemical reaction
Autorzy:
Szostak, Elżbieta
Odrowąż, Ewa
Górska, Natalia
Powiązania:
https://bibliotekanauki.pl/articles/1430228.pdf
Data publikacji:
2020
Wydawca:
Towarzystwo Chemii i Inżynierii Ekologicznej
Tematy:
Boudouard reaction
equilibrium constant
inquiry-based science education
chemical experiment
reakcja Boudouarda
stała równowagi
edukacja naukowa
edukacja naukowa oparta na dociekaniach
eksperymenty chemiczne
Opis:
One of the fundamental elements of a scientist's work is the ability to lead observations of the phenomena that surround us and based on them making conclusions. These observations are conducted within the so-called scientific experiments. Lessons learned based on the results obtained in experiments allow researchers to better understand the essence of the phenomena occurring in the world around us. Drawing conclusions is not always easy. In order to achieve this skill, we must possess a well-established knowledge in the field of the phenomenon that interests us. The most striking example of how important skills are observation and drawing proper conclusions is the phenomenon of global climate warming. The main parameter influencing temperatures registered on Earth is the concentration of greenhouse gases in the atmosphere, and especially carbon dioxide created from combustion processes. A significant role in studies of the reduction of CO2 emissions plays chemists. To be sure that conducted by them experiments are optimally designed, it is necessary to ensure them with proper education already at the secondary school level. The main aim of this article was to conduct the study in order to explain chemical issues that create the greatest cognitive difficulties among students. The second aim of the article was to propose a chemical experiment to students that would allow them to find out more about the phenomena governing in the area of problematic issues. The proposed experiment is based on the concept of solubility equilibrium. Results of preliminary tests that have been carried out after applying this experiment on a small group of students, indicated their better understanding of the studied subject.
Źródło:
Chemistry-Didactics-Ecology-Metrology; 2020, 25, 1-2; 101-111
2084-4506
Pojawia się w:
Chemistry-Didactics-Ecology-Metrology
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:
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:
Direct measurements of reaction time for extractive processes
Autorzy:
Gotfryd, L.
Becker, K.
Pietek, G.
Szołomicki, Z.
Piwowonska, J.
Powiązania:
https://bibliotekanauki.pl/articles/109772.pdf
Data publikacji:
2016
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
reaction time
solvent extraction
viscosity
stripping rate
sulphuric acid
Opis:
Extraction times for selected metal cations (Mg2+, Al3+, Zn2+, Cd2+, Cu2+, Ni2+, Co2+, Mn2+, Fe2+ and Fe3+) have been measured using cation-exchanging extractants - Versatic 10 (neodecanoic acid), DEHPA (bis(2-ethylhexyl)phosphoric acid) and Cyanex 272 (bis(2,4,4-trimetylpentyl)phosphinic acid). Data was collected directly by measuring and recording pH of the two phase reaction mixture with maintaining continuity of the aqueous phase. Similarly, the stripping rate of selected cations (Mg2+, Al3+, Zn2+, Cu2+, Ni2+, Co2+) in a sulphuric acid solution was measured. Viscosities of organic phases, saturated with cations, were measured before their stripping. Additionally, the extraction dependence of Mg2+, Al3+, Fe2+ and Fe3+ on pH was measured using Versatic 10 at various concentrations (7.5, 15 and 30 %).
Źródło:
Physicochemical Problems of Mineral Processing; 2016, 52, 2; 909-919
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of embedded retaining wall using the subgrade reaction method
Autorzy:
Pasik, T.
Chalecki, M.
Koda, E.
Powiązania:
https://bibliotekanauki.pl/articles/178301.pdf
Data publikacji:
2015
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
earth pressure
internal forces
displacements
Subgrade Reaction Method
retaining wall
Opis:
This paper analyzes the distribution of internal forces and displacements of embedded retaining wall in Quaternary deposits and Tertiary clays. Calculations have been based on the Subgrade Reaction Method (SRM) for two different types of earth pressure behind the wall (active, at-rest) in order to show the differences resulting from adopting the limit values. An algorithm for calculation of “cantilever wall” using the Mathematica program was proposed.
Źródło:
Studia Geotechnica et Mechanica; 2015, 37, 1; 59-73
0137-6365
2083-831X
Pojawia się w:
Studia Geotechnica et Mechanica
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:
Elucidation of reaction mechanisms using kinetic isotope effects of short-lived radionuclides
Autorzy:
Matsson, O.
Powiązania:
https://bibliotekanauki.pl/articles/146955.pdf
Data publikacji:
2002
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
carbon-11
fluorine-18
kinetic isotope effect
reaction mechanism
short-lived radionuclide
Opis:
The use of the short-lived radionuclides 11C and 18F for the elucidation of organic reaction mechanisms is described. Examples of the different mechanistic problems that are discussed include concerted vs. stepwise base catalysed elimination (E2 or E1cB) and finding the rate limiting step for nucleophilic aromatic substitution (SNAr). The use of radionuclides to learn details about transition state structure for concerted nucleophilic aliphatic substitution (SN2) is also described.
Źródło:
Nukleonika; 2002, 47,suppl.1; 43-45
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Pre-Fortis Shortening in Czech English: A Production and Reaction-Time Study
Autorzy:
Skarnitzl, Radek
Šturm, Pavel
Powiązania:
https://bibliotekanauki.pl/articles/620756.pdf
Data publikacji:
2016-03-01
Wydawca:
Uniwersytet Łódzki. Wydawnictwo Uniwersytetu Łódzkiego
Tematy:
pre-fortis shortening
vowel duration
voicing
Czech English
reaction times
Opis:
This study focuses on the production and perception of English words with a fortis vs. lenis obstruent in the syllable coda. The contrast is mostly cued by the duration of the preceding vowel, which is shorter before fortis than before lenis sounds in native speech. In the first experiment we analyzed the production of 10 Czech speakers of English and compared them to two native controls. The results showed that the Czech speakers did not sufficiently exploit duration to cue the identity of the word-final obstruent. In the second experiment we manipulated C and V durations in target words to transplant the native ratios onto the Czech-accented speech, enhancing the fortis-lenis contrast, and vice versa. 108 listeners took part in a word-monitoring task in which reaction times were measured. The hypothesized advantage to items in which the target word (with a fortis or lenis obstruent) was semantically congruent with the following context was not confirmed, and subsequent analyses showed that the words’ frequency of use and the collocations they enter into strongly affect speech processing and correlate to a large degree with the reaction times.
Źródło:
Research in Language; 2016, 14, 1; 1-14
1731-7533
Pojawia się w:
Research in Language
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:
Action-reaction based synthesis of acoustic wavefield equations
Autorzy:
Lasota, H.
Powiązania:
https://bibliotekanauki.pl/articles/331802.pdf
Data publikacji:
2011
Wydawca:
Polskie Towarzystwo Akustyczne
Opis:
The analysis of acoustic fields is usually based on the well-known mathematics of second order partial differential equations called wave equations. The author explores the duality and symmetry of linear fluid mechanics and develops two distinct equations of acoustics on the basis of a causal approach to local small-scale phenomena. Wavefields that are solutions of these equations have different composition, the spherical pressure wave being only a specific components of one of them. A new perspective on the phenomena, presented in this paper, endeavours to establish the right equilibrium between mathematical formalism and physical phenomenology in the perception of acoustic wavefields.
Źródło:
Hydroacoustics; 2011, 14; 111-118
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Progress towards a local expression for radiation reaction
Autorzy:
Capon, Rachel
Powiązania:
https://bibliotekanauki.pl/articles/1342575.pdf
Data publikacji:
1997
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Opis:
We report on progress towards finding a local expression for radiation reaction for a particle orbiting a Kerr black hole. The Dirac-Gal'tsov approach is described. For the case of a scalar particle in a circular orbit of a Schwarzschild black hole, an explicit calculation is done via this method and shown to be in agreement with overall energy conservation. A possible approach to the case of more general orbits is also discussed.
Źródło:
Banach Center Publications; 1997, 41, 2; 65-70
0137-6934
Pojawia się w:
Banach Center Publications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Reakcja Niementowskiego
The Niementowski reaction
Autorzy:
Łysakowska, M.
Piotrowska, D. G.
Powiązania:
https://bibliotekanauki.pl/articles/172007.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Chemiczne
Tematy:
reakcja Niementowskiego
chinolina
chinazolina
chinazolin-4-on
kwas antranilowy
Niementowski reaction
quinoline
quinazoline
quinazolin-4-one
anthranilic acid
Opis:
The Niementowski reaction depends on the fusion of anthranilic acid with carbonyl compounds or amides and dates back to the end of the nineteenth century. Numerous variations of the reaction components and modifications of the reaction conditions have appeared in the literature through years. Besides anthranilic acid other synthons including: methyl o-aminobenzoate [25], o-nitrobenzoic acid [26], o-acylaminobenzamide [21], o-aminobenzamide [27], o-aminobenzonitrile [28], isatoic anhydride [29], benzoxasinone [30, 31] have been employed as well. Replacement of the amide component with either amine [9, 32], nitrile [33], imidate [34], thioamide [35], amidine [36], aldehyde [37] or carboxylic acid [28] have also been reported. To increase yield and to reduce the reaction time a number of variables in reaction conditions have been investigated. The best results have been achieved by implementation of a microwave irradiation [38]. The Niementowski reaction and its variants have found widespread use in pharmaceutical and agrochemical fields for the synthesis of compounds containing quinoline and quinazoline systems which are present in a number of natural and synthetic alkaloids [12, 13] and many drugs [1–5].
Źródło:
Wiadomości Chemiczne; 2015, 69, 5-6; 369-390
0043-5104
2300-0295
Pojawia się w:
Wiadomości Chemiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Reaction-diffusion coupled inclusions with variable exponents and large diffusion
Autorzy:
Simsen, Jacson
Stefanello Simsen, Mariza
Wittbold, Petra
Powiązania:
https://bibliotekanauki.pl/articles/2052022.pdf
Data publikacji:
2021
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
reaction-diffusion coupled systems
variable exponents
attractors
upper semicontinuity
large diffusion
Opis:
This work concerns the study of asymptotic behavior of coupled systems of p(x)-Laplacian differential inclusions. We obtain that the generalized semiflow generated by the coupled system has a global attractor, we prove continuity of the solutions with respect to initial conditions and a triple of parameters and we prove upper semicontinuity of a family of global attractors for reaction-diffusion systems with spatially variable exponents when the exponents go to constants greater than 2 in the topology of [formula] and the diffusion coefficients go to infinity.
Źródło:
Opuscula Mathematica; 2021, 41, 4; 539-570
1232-9274
2300-6919
Pojawia się w:
Opuscula Mathematica
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:
Hydrogen evolution reaction at Ru-modified nickel-coated carbon fibre in 0.1 M NaOH
Autorzy:
Pierożyński, B.
Mikołajczyk, T.
Powiązania:
https://bibliotekanauki.pl/articles/778010.pdf
Data publikacji:
2015
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
NiCCF
Ru-modification
hydrogen evolution reaction
HER
impedance spectroscopy
Opis:
The electrochemical activity towards hydrogen evolution reaction (HER) was studied on commercially available (Toho-Tenax) and Ru-modified nickel-coated carbon fibre (NiCCF) materials. Quality and extent of Ru electrodeposition on NiCCF tows were examined by means of scanning electron microscopy (SEM). Kinetics of the hydrogen evolution reaction were investigated at room temperature, as well as over the temperature range: 20-50°C in 0.1 M NaOH solution for the cathodic overpotential range: -100 to -300 mV vs. RHE. Corresponding values of charge-transfer resistance, exchange current-density for the HER and other electrochemical parameters for the examined fibre tow composites were recorded.
Źródło:
Polish Journal of Chemical Technology; 2015, 17, 1; 18-22
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Platinum dissolution and ethanol oxidation reaction on Pt-activated nickel foam in sodium hydroxide solution
Autorzy:
Pierozynski, B.
Mikolajczyk, T.
Powiązania:
https://bibliotekanauki.pl/articles/779425.pdf
Data publikacji:
2017
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
Pt-activated nickel foam
ethanol oxidation reaction
Pt-dissolution
Opis:
Electrochemical oxidation of ethanol becomes an important process of modern electrochemistry, due to its potential application into direct ethanol fuel cell technology. As rates of ethanol oxidation reaction (EOR) are significantly enhanced in alkaline media, employment of highly corrosion resistant under alkaline conditions, but non-noble metals becomes of superior practical importance. This communication article reports on the process of anodic dissolution of platinum, which is investigated on Pt activated, electrooxidized nickel foam electrodes, employed for ethanol oxidation reaction in 0.1 M sodium hydroxide solution. The above was revealed through the application of cyclic voltammetry and combined SEM/EDX (scanning electron microscopy and energy dispersive x-ray) spectroscopy examinations.
Źródło:
Polish Journal of Chemical Technology; 2017, 19, 3; 41-43
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
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:
The Inverse Reaction Cross Sections for Some Charged Particles Using the Optical Model Parameters
Autorzy:
Ahmed, Rasha S.
Powiązania:
https://bibliotekanauki.pl/articles/1193016.pdf
Data publikacji:
2016
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Optical reaction cross-sections
charged particles
neutrons
pre-equilibrium models
Opis:
p-nucleus, (_1^2)H-nucleus, (_1^3)H-nucleus, and (_2^4)He-nucleus inverse reaction cross sections have been determined using the optical model potentials in a wide range of target nuclei started from A=1 to A=232 using several incident particle energies ( E = 2, 8, 10, 20, and 40 MeV). In this work, a large number of optical model available parameters were used to calculate the inverse reaction cross section and compared to investigate the effect of the mass number and incident particle energy on the inverse reaction cross section. All the calculations were performed using MATHLAB programming language.
Źródło:
World Scientific News; 2016, 28; 72-83
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of acoustic emission to monitoring the course of the alkali-silica reaction
Autorzy:
Świt, G.
Zapała-Sławeta, J.
Powiązania:
https://bibliotekanauki.pl/articles/200502.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
alkali-silica reaction
acoustic emission
corrosion
microstructre
AE descriptors
Opis:
The study presented research on the possibility of using acoustic emission to detect and analyze the development of the alkali-silica reaction (ASR) in cement mortars. The experiment was conducted under laboratory conditions using mortars with reactive opal aggregate, accelerating the reaction by ensuring high humidity and temperature, in accordance with ASTM C227. The progress of corrosion processes was monitored continuously for 14 days. The tests were complemented with measurements of the expansion of the mortars and observations of microstructures under a scanning electron microscope. The high sensitivity of the acoustic emission method applied to material fracture caused by ASR enabled the detection of corrosion processes already on the first day of the test, much sooner than the first recorded changes in linear elongation of the specimens. Characteristic signal descriptors were analyzed to determine the progress of corrosion processes and indicate the source of the cracks. Analysis of recorded 13 AE parameters (counts total, counts to peak, duration, rise time, energy, signal strength, amplitude, RMS, ASL, relative energy, average frequency, initial frequency and reverberation frequency) indicates that the number of counts, signal strength and average frequency provide most information about the deleterious processes that occur in the reactive aggregate mortars. The values of RA (rise time/amplitude) and AF (average frequency) enabled the classification of detected signals as indicating tensile or shear cracks. The acoustic emission method was found suitable for monitoring the course of alkali-aggregate reaction effects.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2020, 68, 1; 169-178
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation of alkali-aggregate reaction in carbonate rocks
Badania realcji alkalia-kruszywo dla skał węglanowych
Autorzy:
Owsiak, Z.
Powiązania:
https://bibliotekanauki.pl/articles/402374.pdf
Data publikacji:
2010
Wydawca:
Politechnika Świętokrzyska w Kielcach. Wydawnictwo PŚw
Tematy:
reakcja alkalia-kruszywo
reakcja alkalia-węglany ACR
alkali-aggregate reaction (AAR)
ACR
Opis:
Alkali-aggregate reaction (AAR) may occur in concrete through siliceous or carbonate rock and alkaline hydroxides. Depending on the type of minerals present in the rock, it is possible the alkali-silica/silicate (ASR), alkali-carbonate (ACR) or both reactions occurrences. The preliminary study of the rock is an obligatory procedure before the application in a concrete structure. This paper presents a laboratory study with the main purpose of verifying the potential in causing alkali-silica and alkalicarbonate reactivity of dolomite rock. With this approach, several methodologies in the ASR and ACR investigations and a detailed mineralogical analysis of the mentioned rocks are showed and the tested results discussed. The results indicate that alkali-silica reaction does not occur in non-siliceous carbonate aggregate even with a very low content of SiO2.
Źródło:
Structure and Environment; 2010, 2. no. 3; 25-31
2081-1500
Pojawia się w:
Structure and Environment
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Diagnosis of concrete structures distress due to alkali-aggregate reaction
Autorzy:
Owsiak, Z.
Zapała-Sławeta, J.
Czapik, P.
Powiązania:
https://bibliotekanauki.pl/articles/201887.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
alkali-aggregate reaction
diagnosis
concrete structure
reakcja alkalia-kruszywo
rozpoznanie
struktura betonu
Opis:
Damage and defects observed in concrete elements, such as a network of microcracks, popouts and eflorrescence can be caused by a variety of deleterious processes. The causes can include mechanical (overloading), physical (freeze-thaw cycle) or chemical exposure (sulphate corrosion, alkali-aggregate reaction). This paper analyses distress due to alkali-silica reaction, detected in selected concrete structures. The analysed concrete elements exhibited cracking, exudations and surface popouts. Identification of the presence of hydrated sodium-potassiumcalcium silicate gel can be considered the primary symptom suggestive of an alkali-silica reaction attack. Other damage-causing mechanisms can occur simultaneously.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2015, 63, 1; 23-29
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Badania kinetyki reakcji CO2 z N-metylodietanoloaminą
Investigations into the kinetics of reaction between CO2 and N-methyldiethanolamine
Autorzy:
Moniuk, Wł.
Pohorecki, R.
Mamza, R.
Powiązania:
https://bibliotekanauki.pl/articles/2070958.pdf
Data publikacji:
2010
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
ditlenek węgla
N-metylodietanoloamina
absorpcja z reakcją chemiczną
stała szybkości reakcji
carbon dioxide
N-methyldiethanolamine
absorption with chemical reaction
reaction rate constant
Opis:
Wykonano badania szybkości absorpcji CO2 w wodnych roztworach N-metylodietanoloaminy w reaktorze barbotażowym z mieszadłem. Na podstawie tych badań określono wartości stałej szybkości reakcji CO2 z N-mctylodictanoloaminą. Wodne roztwory tej aminy mogą być stosowane jako rozpuszczalnik w procesie oczyszczania gazów syntezowych i odlotowych od ditlenku węgla.
The measurements of CO2 absorption rate in aqueous solutions of N-methyldiethanolamine were carried out in a stirred reactor. On the basis of these measurements the reaction rate constant values between C02 and N-methyldiethanolamine were determined. It was concluded that aqueous solutions of these amines might be promising solvents in the waste processing and synthesis gases purification from carbon dioxide.
Źródło:
Inżynieria i Aparatura Chemiczna; 2010, 2; 85-86
0368-0827
Pojawia się w:
Inżynieria i Aparatura Chemiczna
Dostawca treści:
Biblioteka Nauki
Artykuł

Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies