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Tytuł:
Hydrothermal carbonization processes to increase the transportability of plant biomasses
Autorzy:
Schlegel, M.
Ibrahim, B.
Fras, J.
Kanswohl, N.
Zosel, J.
Powiązania:
https://bibliotekanauki.pl/articles/409568.pdf
Data publikacji:
2018
Wydawca:
Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Tematy:
transportability
plant biomasses
process
Opis:
Plant biomasses often have high water content and their energy and material density is too low, which significantly affects their high transport costs. Hydrothermal carbonization is a suitable method to increase the transportability of these biomasses. The produced biochar (HTC-char) is rich in carbon. Disadvantages of such carbonization process are the quality fluctuations of the biochars produced. This is also because there are to date no suitable measuring methods for the carbonization process. The paper presents a novel method, which will help to influence the carbonization process in the sense of qualitatively equivalent biochars by means of the achievable data therewith.
Źródło:
Research in Logistics & Production; 2018, 8, 2; 169-178
2083-4942
2083-4950
Pojawia się w:
Research in Logistics & Production
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Copper (II) Oxide particles as Adsorbent for Removal of Alkali Blue; Isotherm and Kinetic Studies
Autorzy:
Ibrahim, M. A.
Ibrahim, M. B.
Powiązania:
https://bibliotekanauki.pl/articles/1158766.pdf
Data publikacji:
2018
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Adsorption
Copper (II) Oxide particles
FTIR
Isotherm
Kinetics
Opis:
Adsorption behaviour of copper (II) oxide particles (CuO-Ps) for the removal of Alkali Blue (AB) was studied. Different adsorption variables such as contact time, initial concentration and pH for the adsorption process were investigated by batch adsorption studies. FTIR was carried out to determine the functional groups present at the surface of the particle with functional groups such as –OH, C=C, C-H, C≡C detected. The percentage removal and optimum contact time for the removal of AB was 84.8% at 10 min. The experimental isotherms data were analyzed using Langmuir, Temkin, Freundlich and Dubinin-Radushkevich (D-R) isotherms and it was observed that AB fits closely to Langmuir with R2 value of 0.884. Kinetics studies shows that the adsorption process fits better to pseudo-second order with the experimental values of qe 4.242 been closer to the calculated values of the qe 4.108. Effect of pH shows that it adsorb better at the initial pH of 5.30. Lower value of mean square energy of 0.707 kJ/mol indicates that the adsorption process is physical. The results indicated that copper (II) oxide particle can be used as a low-cost adsorbent for the removal of AB from aqueous solutions.
Źródło:
World Scientific News; 2018, 114; 208-217
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Medicinal plants for management and alternative therapy of common ailments in Dutsin-Ma (Katsina State) in Nigeria
Autorzy:
Sadoq, I.Z.
Abubakar, F.S.
Ibrahim, B.
Usman, M.A.
Kudan, Z.B.
Powiązania:
https://bibliotekanauki.pl/articles/2048979.pdf
Data publikacji:
2019
Wydawca:
Instytut Włókien Naturalnych i Roślin Zielarskich
Tematy:
ethnobotanical survey
medicinal plants
traditional herbalist
common ailments
alternative therapy
badanie etnobotaniczne
rośliny zielarskie
zielarze ludowi
typowe schorzenia
terapia alternatywna
Opis:
Introduction: Nowadays, many synthetic drugs comes with various degrees of side effects, accumulative toxicity and development of resistance by microorganisms. Medicinal plants used worldwide can be developed into modern drugs with little or no side effects and greater efficacy. Objective: The aim of this paper was to document the alternative therapy used in Dutsin-Ma local community in Katsina state, Nigeria. Methods: Ethnobotanical survey was carried out among 40 traditional herbalists. Out of 106 plants found, screening was conducted to include only plants that are prescribed simultaneously by the entire herbalists. Results: We have found 32 species of medicinal plants from 20 families that are used for management and alternative therapy against common ailments such as malaria, diabetes, sickle cell anaemia, hypertension, ulcer, paralysis, typhoid fever and immune deficiency. Conclusion: Traditional medicinal plants provide the alternative therapy for treatment and management of diseases to significant number of people. Herbal practitioners are still relevant to African healthcare system.
Źródło:
Herba Polonica; 2019, 65, 4; 45-55
0018-0599
Pojawia się w:
Herba Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Logistical Advantages Due to the Use of an Innovative Sensor Unit for Controlling Optimum Biogas Processes
Autorzy:
Schlegel, M.
Fras, J.
Geick, T.
Zosel, J.
Schelter, M.
Kritzner, A.
Orth, M.
Ibrahim, B.
Kanswohl, N.
Powiązania:
https://bibliotekanauki.pl/articles/409594.pdf
Data publikacji:
2016
Wydawca:
Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Tematy:
remote control
biogas process
sensor unit
Opis:
For imaging of the biogas process fast and long-term stable measurement methods misses for certain parts of the process. Thus, it is necessary to know the development of organic acids. These metabolites, which are generated during the bacterial degradation, are important indicators. The process is generally very confusing, not only in terms of the number of occurring bacteria and chemical compounds, but also their variabilities. For the knowledge of such changes a direct, low-wear and permanent monitoring of organic acids would be extremely useful. Upon the occurrence of a change like hyperacidity we could react quickly. There are already some proven methods. However, these methods have several disadvantages: the information gathering is logistically difficult by long journeys, by process conditions information’s are delayed and distorted, quickly worn sensors, etc. Therefore, a innovative development is presented here, which avoids all the disadvantages listed. The sensor unit has been developed in cooperation with KSI Meinberg, Logic Way Schwerin, IBZ Hohen Luckow, University of Rostock and a polish colleague. According to Raoult law a characteristic is used in principle, which is typical of some liquid and gaseous media that are touching. This means volatile substances, which for example, are also in the fermenter broth, among others organic acids, are also detectable in the gaseous phase. If in the gas phase such acids can be detected, conclusions about the acid content in the substrate broth are possible. In different experiments evaluable matches between the developments of organic acids on the one hand in the liquid phase (broth) and on the other hand, in the gaseous phase were found. These results are based on an acid sensor unit with which distant standing biogas plants can be controlled remotely. A project regarding this topic is supported by research programme ZIM. Project executing organization is AiF (Arbeitsgemeinschaft industrieller Forschungsvereinigungen “Otto von Guericke” e.V.).
Źródło:
Research in Logistics & Production; 2016, 6, 5; 407-418
2083-4942
2083-4950
Pojawia się w:
Research in Logistics & Production
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An Analysis of Solar Burst Type II, III, and IV and Determination of a Drift Rate of a Single Type III Solar Burst
Autorzy:
Hamidi, Z. S.
Ibrahim, M. B.
Shariff, N. N. M.
Monstein, C.
Powiązania:
https://bibliotekanauki.pl/articles/411732.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
sun
solar burst
type II,III,IV
radio region
X-ray region
solar flare
active region
Opis:
The main feature of solar radio type II, III and IV burst is outlined. In this event there are three combinations of bursts that related to the solar flare phenomenon on 6th July 2012. This event is one of good example to observe how far the influence of type II burst could impact the formation of type IV burst and III solar bursts. At first stage, it was observed that a sub-type of H burst form within 2 minutes before type IV solar burst form. The type IV burst is due to the eruption of active region AR 1515 with a fine structure (FS). We used a Blein CALLISTO data in this case. Further analysis also showed that the total energy of the burst are in the range of 4.875 × 10-25 J to 8.48 × 10-25 J and plasma frequency is equal to 1.24 × 104 Hz. Therefore, we could say that in this case, before the solar burst type III occurred, the ejection of CMEs already ejected.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 19, 2; 160-170
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Case Study of Explosion A Single Solar Burst Type III and IV Due to Active Region AR1890
Autorzy:
Hamidi, Z. S.
Ibrahim, M. B.
Shariff, N. N. M.
Monstein, C.
Powiązania:
https://bibliotekanauki.pl/articles/412554.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
sun
solar burst
III
IV
radio region
X-ray region
solar flare
active region
Opis:
Using data from a BLEIN Callisto site, we aim to provide a comprehensive description of the synopsis formation and dynamics of a a single solar burst type III and IV event due to active region AR1890. This eruption has started since 14:15 UT with a formation of type III solar burst. To investigate the importance of the role of type III solar burst can potentially form a type IV solar burst, the literature review of both bursts is outlined in detailed. The orientation and position of AR1890 make the explosion of a class C-solar flare is not directly to the Earth. Nevertheless, it is clear that the interactions of others sunspots such as AR1893,AR1895,AR1896, AR1897 and AR1898 should be studied in detail to understand what makes the type III burst formed before the type IV solar burst.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 19, 2; 171-180
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation on a Broken Solar Burst Type II during High Activities in AR1613 on 13th November 2012
Autorzy:
Hamidi, Z. S.
Shariff, N. N. M.
Monstein, C.
Zulkifli, W. N. A. W.
Ibrahim, M. B.
Arifin, N. S.
Amran, N. A.
Powiązania:
https://bibliotekanauki.pl/articles/411666.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
sun
low frequency
solar radio
burst
type II
type III
e-CALLISTO
Opis:
The present article is an attempt to analyze the solar burst Type II observations based on solar flare and Coronal Mass Ejections (CMEs) events. We choose an intriguing type II radio burst with a velocity of 1193 kms-1 that occurred on 2012 November 13 at 2:04:20 UT. In this case, the study of solar radio burst type III is of paramount importance because of the fact that it helps to gain an insight of generation mechanisms of solar flare and Coronal Mass Ejections (CMEs) phenomena. Here, we have got a reasonably clear idea of the various forms under which the type III continuum emission may appear and potentially form a type II burst. However, in this case, the Type II solar burst only successfully forms a fundamental structure within the first few minute period, but broken suddenly before evolve a harmonic structure. This phenomenon is very interesting to be tackled and study. How the burst suddenly broken is still ongoing research seems the event is very rare and hard to be proved. There are a few questions that cause this unique situation which related to: (i) the intensity and duration of type III burst which also related to the classification of solar flare (ii) the probabilities CMEs to occur during that time and also the factor of the total amount of massive burst that exploded, Thus, we can conclude that the solar burst type III event still tells us an enigmatic characteristic from time to time due to the relationship of energetic particles and streams of particles with coronal magnetic fields and the pattern of Sun activity due to the 24th solar cycle. It might an interesting to study in detail the main factor that caused the Type II solar burst broken. Indirectly, it might because of the very intense of solar flares that make the percentage of energy of solar flare become more dominant rather than the acceleration of particles through the Coronal Mass Ejections. Thus, we realize that the potential energy during this event is higher than the kinetic energy of the particles.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 9; 8-15
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Observation of the Radio Frequency Interference (RFI) at the National Space Centre, Malaysia
Autorzy:
Hamidi, Z.S.
Shariff, N.N.M.
Monstein, C.
Wan Zulkifli, W.N.A.
Ibrahim, M.B.
Arifin, N.S.
Amran, N.A.
Powiązania:
https://bibliotekanauki.pl/articles/11076.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
observation
Radio Frequency Interference
National Space Centre
Sun
astronomy
solar monitoring
e-CALLISTO system
Malaysia
Opis:
Important results of the Radio Frequencies Interference (RFI) at the National Space Centre, Sg Lang Selangor, Malaysia has been reported. In order to make sure that the data of solar monitoring in radio region is reliable, we need to study the variation of interference and the possible sources that contribute to this interference. This data has been taken from 1-2000 MHz at the main site of installation e-CALLISTO system. The study is one of a main part of an initiative of e-CALLISTO networking research in order to identify the main RFI sources and to monitor continuously the behavior of the RFI at the site. Our main objective is to qualify the potential of monitoring a continuous radio emission of the Sun. This work is also an initiative of the International Space Weather Initiative (ISWI) project where Malaysia is one of the countries that joined the e-CALLISTO network. Due to our results this site showed the positive impact for the solar monitoring purpose. It is hoped that the survey will continue from time to time in a consistent mode so that any polluted signal for radio astronomy purpose can be protected. Overall, we can still get a good solar burst data, especially at 40-400 MHz. Perhaps, we can contribute the good data for solar burst monitoring towards the maximum cycle beginning the end of this year 2013.
Źródło:
International Letters of Natural Sciences; 2014, 05
2300-9675
Pojawia się w:
International Letters of Natural Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An X-ray Observations of A Gradual Coronal Mass Ejections (CMEs) on 15th April 2012
Autorzy:
Hamidi, Z. S.
Shariff, N. N. M.
Monstein, C.
Wan Zulkifli, W. N. A.
Ibrahim, M. B.
Arifin, N. S.
Amran, N. A.
Powiązania:
https://bibliotekanauki.pl/articles/411850.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Sun Coronal Mass Ejections (CMEs)
solar corona
solar flare
solar cycle
Opis:
In the present work, we will highlight the solar observation during 15th April 2012, solar filament eruption which is accompanied by an intense and gradual Coronal Mass Ejections (CMEs) The explosion of CMEs was observed at 2:12:06 UT and also can be observed by the Solar Dynamics Observatory (SDO) with an Active Region AR1458 is crackling with C-class solar flares. The solar flare class B3 and C2 were observed beginning 2241 UT and 0142 UT. The event is considered as second largest CMEs been detected since five years. Although the solar activity within a few days is considered quite low and there are no proton events were observed at geosynchronous orbit., the is still an unexpected explosion of CMEs can be occurred. The radio flux number (10.7 cm) exceeds 102 with the number of sunspot and area of sunspot increased to 77 and 270. The velocity of CMEs was calculated based on the LASCO2 data. From the results, it is clearly seen that the range of the velocity is between 200 kms-1 to 2000 kms-1. This wide of range proved that the mechanism of the CMEs is a gradual process. The explosion of CMEs velocity is located from 80º - 255º from North of the Sun. We can then conclude that currently, the rearrangement of the magnetic field, and solar flares may result in the formation of a shock that accelerates particles ahead of the CMEs loop and an active region play an important character in this event.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 8; 13-19
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Correlation between Solar Flare Phenomena in an X-ray Region and Radio Flux Measurement from January to September 2010
Autorzy:
Hamidi, Z. S.
Shariff, N. N. M.
Ali, M. F.
Monstein, C.
Zulkifli, W. N. A. W.
Ibrahim, M. B.
Arifin, N. S.
Amran, N. A.
Powiązania:
https://bibliotekanauki.pl/articles/411743.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
sun
chromospheres
flares
radio flux
solar activity
Opis:
A short term variation of solar flare in nine months (January 2010 to September 2010) is presented. This paper review and analyze the correlation between radio flux strength measurement and solar flare in the X-ray region. The radio flux measurement data were taken from the National Research Council; Ottawa while hard X-ray emission observed by Royal Observatory of Belgium. The overall range of solar radio flux recorded in this study ranging from 68 x 10-22 Wm-2Hz-1 to 96 x 10-22 Wm-2Hz-1. As there was no class of an X of solar flare reported at all in this study, we can confirm that there are no major effects that happened on Earth and outer space such as Coronal Mass Ejections (CMEs) and solar storms. We concluded that the Sun shows a very minimum activity towards 24th solar cycle.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 9; 84-92
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Understanding forest land conversion for agriculture in a developing country context: An application of the theory of planned behaviour among a cohort of Nigerian farmers
Autorzy:
Ibrahim, F.M.
Osikabor, B.
Olatunji, B.T.
Ogunwale, G.O.
Powiązania:
https://bibliotekanauki.pl/articles/28407578.pdf
Data publikacji:
2022
Wydawca:
Instytut Badawczy Leśnictwa
Źródło:
Folia Forestalia Polonica. Series A . Forestry; 2022, 64, 3; 117-130
0071-6677
Pojawia się w:
Folia Forestalia Polonica. Series A . Forestry
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Czynnik stymulujący tworzenie kolonii granulocytów (G-CSF) jako nowy biomarker w spersonalizowanej terapii raka jelita grubego?
Granulocyte colony stimulating factor (G-CSF) as a new biomarker for personalized treatment of colorectal cancer?
Autorzy:
Wawrzyniec, K.
Kawczyk-Krupka, A.
Flak, B.
Ibrahim, O.
Sieroń, A.
Powiązania:
https://bibliotekanauki.pl/articles/261427.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Wydział Podstawowych Problemów Techniki. Katedra Inżynierii Biomedycznej
Tematy:
G-CSF
rak jelita grubego
terapia spersonalizowana
colon cancer
personalized therapy
Opis:
Rak jelita grubego jest drugą przyczyną zgonów w populacji pacjentów onkologicznych. Pomimo ciągłego rozwoju metod diagnostycznych, wprowadzania programów badań przesiewowych, systematycznej kontroli pacjentów będących już po interwencji chirurgicznej lub chemioterapii, osiągane finalne efekty przeżycia chorych z rakiem jelita grubego nie są zadowalające. Przyczyną tak niesatysfakcjonujących wyników jest częste wykrywanie choroby już w zaawansowanym stadium, gdyż u co trzeciego chorego w momencie rozpoznania raka jelita grubego potwierdzone są przerzuty. Powszechnie stosowane, celem detekcji zmian nowotworowych i późniejszej kontroli nawrotu choroby, markery CEA i CA 19-9 nie są wystarczające. Z tego powodu konieczne są dalsze poszukiwania znaczników, które w połączeniu z dotychczas stosowanymi elementami diagnostycznymi, umożliwią z wysoką czułością i swoistością wykrycie raka, wznowy i progresji choroby oraz pozwolą przewidzieć przebieg, a także prawdopodobną odpowiedź na standardowe leczenie. Oparcie podejmowanych decyzji na takich danych i kwalifikowanie pacjenta do niestandardowego schematu leczniczego umożliwi w większym stopniu wdrożenie zindywidualizowanej terapii, która powinna odgrywać podstawową rolę w leczeniu.
The colorectal cancer (CRC) is the second cause of death in the entire population of oncological patients. Despite of the development of diagnostic methods, screening programs, monitoring of patients after surgery or chemotherapy, results of survival rates are not satisfactory. The reason is that frequently the detection of the disease takes place already at the advanced stage, as every third patient at the time of diagnosis of CRC has already metastases. CEA and CA 19-9 markers are commonly used to detect cancer and to monitor the disease recurrence, are not sufficient. For this reason it becomes necessary to introduce new additional markers that will enable a higher sensitivity and specificity for detecting cancer, it’s recurrence and progression and will be helpful to predict the course of disease and response to standard therapy. Basing on an advanced diagnosis, an individualized therapy implementation will be possible. This approach should play a key role in the proper treatment.
Źródło:
Acta Bio-Optica et Informatica Medica. Inżynieria Biomedyczna; 2013, 19, 3; 148-153
1234-5563
Pojawia się w:
Acta Bio-Optica et Informatica Medica. Inżynieria Biomedyczna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis and properties of vinylpyrrolidone/ (trimethoxysilyl)propyl methacrylate gels containing different amounts of crosslinking agent
Synteza i właściwości żelu N-winylopirolidon/metakrylan3-(trimetoksysililo)propylu z różną zawartością czynnika sieciującego
Autorzy:
Mohammed, A. H.
Ahmad, M. B.
Ibrahim, N. A.
Zainuddin, N.
Powiązania:
https://bibliotekanauki.pl/articles/947044.pdf
Data publikacji:
2018
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Chemii Przemysłowej
Tematy:
high conversion copolymers
swelling parameters
mechanical properties
oxygen permeability
crosslinking density
kopolimery o wysokim stopniu konwersji
parametry pęcznienia
właściwości mechaniczne
przepuszczalność tlenu
gęstość sieciowania
Opis:
High conversion copolymers containing 90 wt % of N-vinylpyrrolidone (NVP) and 10 wt % of 3-(trimethoxysilyl)propyl methacrylate (TMSPM) with 0, 1, 2, 3 and 4 wt % (in conversion to mass of NVP/TMSPM) of ethylene glycol dimethacrylate (EGDMA) as crosslinker have been successfully synthesized. Proton nuclear magnetic resonance (1H NMR) and Fourier transform infrared spectroscopy (FT-IR) were employed to characterize the resulting copolymers. The effect of EGDMA amount on the mechanical and thermal properties, swelling parameters, clarity, and oxygen permeability of the prepared xerogels and hydrogels were studied. 3 wt % of EGDMA is required to obtain clear xerogels and hydrogels. The water content (EWC), volume fraction of polymer (φ2) and weight loss during swelling decrease with increasing EGDMA content. Young’s and shear modulus (E and G) increase as EGDMA content increases, the values of E and G are 0.570–3.531 MPa and 0.217–1.359 MPa, respectively. The hydrogels were characterized in terms of modulus crosslinking density (ve and vt) and polymer-solvent interaction parameters (χ). The results are 0.220–0.613 mol/dm3 for ve, 0.105–0.441 mol/dm3 for vt, and 0.595–0.822 for χ. Thermal properties enhance by adding EGDMA whereas the oxygen permeability (P) of hydrogels decreases from 48.6 to 44.3 as water content decrease from 70.3 to 55.1.
Kopolimery zawierające 90 % mas. N-winylopirolidonu (NVP) i 10 % masmetakrylanu 3-(trimetoksysililo)propylu (TMSPM) z udziałem 0, 1, 2, 3 i 4 % mas. (w przeliczeniu na masę NVP/TMSPM) dimetakrylanu glikolu etylenowego (EGDMA) jako środka sieciującego zsyntetyzowano z wysokim stopniem konwersji. Otrzymane kopolimery charakteryzowano metodami protonowego rezonansu jądrowego (H1 NMR) i spektroskopii w podczerwieni (FT-IR). Badano wpływ udziału środka sieciującego na właściwości mechaniczne i termiczne, parametry pęcznienia, klarowność i przepuszczalność tlenu wytworzonych hydro- i kserożeli. Stwierdzono, że dodatek już 3 % mas. EGDMA wystarcza do uzyskania klarownego żelu, a w miarę zwiększania zawartości EGDMA zmniejsza się zawartość wody (EWC), ułamek objętości polimeru (φ2) oraz strata masy w procesie pęcznienia żelu NVP/TMSPM. Wartość modułu zarówno Younga (E), jak i ścinania (G) zwiększa się (E = 0,570–3,531 MPa, G = 0,217–1,359 MPa) wraz ze wzrostem udziału EGDMA w kompozycji. Wytworzone hydrożele charakteryzowano za pomocą modułów gęstości sieciowania (ve = 0,220–0,613 mol/dm3, vt = 0,105–0,441 mol/dm3) i parametru oddziaływania polimer-rozpuszczalnik (χ = 0,595–0,822). Właściwości termiczne otrzymanych hydrożeli zawierających EGDMA poprawiły się wraz ze zmniejszeniem zawartości wody (70,3–55,1), natomiast przepuszczalność tlenu się pogorszyła (P = 48,6–44,3).
Źródło:
Polimery; 2018, 63, 9; 577-585
0032-2725
Pojawia się w:
Polimery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis and monomer reactivity ratios of acrylamide with 3-(trimethoxysilyl)propyl methacrylate and tris(methoxyethoxy)vinylsilane copolymers
Współczynniki reaktywności monomerów w syntezie kopolimerów akryloamidu, metakrylanu 3-(trimetoksysililo)propylu i tris(metoksyetoksy)-winylosilanu
Autorzy:
Mohammed, A. H.
Ahmad, M. B.
Ibrahim, N. A.
Zainuddin, N.
Powiązania:
https://bibliotekanauki.pl/articles/947173.pdf
Data publikacji:
2016
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Chemii Przemysłowej
Tematy:
vinylsilane monomers
acrylamide
reactivity ratios
sequence distribution
sekwencja monomerów
Opis:
Copolymers of acrylamide (AM) with 3-(trimethoxysilyl)propyl methacrylate (TMSPMA) and tris(methoxyethoxy)vinylsilane (TMEVS) with different compositions were synthesized at low conversion by free radical polymerization in dimethylformamide (DMF) using benzoyl peroxide (BPO) as an initiator. The copolymers were characterized by Fourier transform infrared spectroscopy (FT-IR), and their thermal properties were studied by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The copolymers composition was determined by elemental analysis. The monomer reactivity ratios were estimated by linearization methods proposed by Fineman-Ross and Kelen-Tudos, the intersection method proposed by Mayo-Lewis and nonlinear method proposed by curve fitting procedure. The derived reactivity ratios (r1, r2) are: 1.87, 0.80 for TMSPMA-co-AM and 0.22, 1.21 for TMEVS-co-AM. Both copolymers formed blocks of one of the monomer units. The microstructure of copolymers and sequence distribution of monomers in the copolymers were calculated by statistical method based on the average reactivity ratios and found that these values are in agreement with the derived reactivity ratios.
Kopolimery akryloamidu (AM) z metakrylanem 3-(trimetoksysililo)propylu (TMSPMA) itris(metoksyetoksy)winylosilanem (TMEVS), o różnych składach, zsyntetyzowano w warunkach małej konwersji metodą wolnorodnikowej polimeryzacji w dimetyloformamidzie (DMF), z zastosowaniem nadtlenku benzoilu (BPO) jako inicjatora. Otrzymane kopolimery charakteryzowano za pomocą spektroskopii w podczerwieni z transformacją Fouriera (FT-IR), różnicowej kalorymetrii skaningowej (DSC) oraz analizy termograwimetrycznej (TGA). Skład kopolimerów ustalono metodą analizy elementarnej. Współczynniki reaktywności monomerów oszacowano metodami linearyzacji zaproponowanymi przez: Finemana-Rossa, Kelena-Tudosa, Mayo-Lewisa i metodą nieliniową z zastosowaniem procedury dopasowania krzywej. Otrzymane współczynniki reaktywności (r1, r2) wynosiły: 1,87 i 0,80 dla TMSPMA-co-AM oraz 1,21 i 0,22 dla TMEVS-co-AM. Oba kopolimery miały budowę złożoną zbloków utworzonych z jednostek monomerów składowych. Mikrostrukturę oraz sekwencję monomerów w kopolimerach wyznaczono metodą statystyczną na podstawie średnich współczynników reaktywności. Stwierdzono zgodność obliczeń z wartościami otrzymanymi doświadczalnie.
Źródło:
Polimery; 2016, 61, 11-12; 758-765
0032-2725
Pojawia się w:
Polimery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Theoretical study of the effect the hydroxyl subgroups on the electronic properties of iso-indene molecule
Autorzy:
Obayes, Abbas Ibrahim
Hasan, Nahida B.
Aboud, Hamed Ibrahem
Mohammed, Mohammed Ahmed
Powiązania:
https://bibliotekanauki.pl/articles/1191969.pdf
Data publikacji:
2016
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
DFT
energy gap
ionization potential
hardness and IR-spectrum
Opis:
In this work, six molecules model are optimized at B3LYP/6-31G** density functional theory. Electronic properties of iso-indene molecules were investigated depending on the three parameters (B3LYP) by density functional theory method. The best geometry for all molecules were investigated at (6-31G**) basis sets. The total energies, energy gaps, ionization potentials, electron affinities and softness were calculated for the studied molecules. Adding the (OH) ion and Nitrogen, Sulfur atoms to the iso-indene molecules leads to decrease the energy gap and the hardness of the studied molecules. The IR-spectra shows the effect of adding the (OH) ion and Nitrogen, Sulfur atoms in the ring on the vibrations of the reference molecule, the electronic properties and IR spectrum for all molecules were investigated by Gaussian 03 program.
Źródło:
World Scientific News; 2016, 50; 49-63
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
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