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Tytuł:
Effects of boldenone undecylenate on growth performance, maintenance behaviour, reproductive hormones and carcass traits of growing rabbits
Autorzy:
Mohammed, H.H.
Badawi, M.E.
El-Tarabany, M.S.
Rania, M.
Powiązania:
https://bibliotekanauki.pl/articles/32097.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Opis:
The present study was done to evaluate the effect of boldenone undecylenate (BOL) on growth performance, maintenance behaviour, reproductive hormones and carcass traits of male rabbits. Sixty apparently healthy New Zealand White male rabbits, 5 weeks of age, were allotted to 3 equal groups. Each group was subdivided into 5 replicates, where the first group is control. The second group (B1) comprised rabbits that received 2 intramuscular injections of BOL (5 mg/kg) with 3 week intervals (9 and 12 weeks of age), while the third group (B2) included rabbits that received 3 intramuscular injections of BOL (5 mg/kg) with 2 week intervals (8, 10 and 12 weeks of age). The end of the trial was after 4 weeks from the last injection (16 weeks of age). The results revealed that the treated groups had a significant increase in total body weight, daily gain and feed efficiency, with a significant decrease in feed conversion ratio (FCR). Ingestive, locomotion and grooming behaviors were significantly higher in treated groups. Lateral pasture and exploratory behaviors were significantly higher in the control group. Administration of BOL resulted in a significant increase in dressing % and a significant decrease in testes %. Groups treated with BOL had a significantly (P<0.05) decreased serum testosterone level, simultaneously with a significantly increased estradiol level. The results indicate that BOL improves performance and carcass traits. Furthermore, there are hormonal-behavioral correlations through enhancement of ingestive and locomotion behaviors of treated animals.
Źródło:
Polish Journal of Veterinary Sciences; 2016, 19, 2
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimization the dynamical parameters of three phase induction motor using genetic algorithm
Autorzy:
Mohammed, M.H.
Powiązania:
https://bibliotekanauki.pl/articles/376222.pdf
Data publikacji:
2012
Wydawca:
Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Tematy:
induction motor
genetic algorithm
differential evolution
DE
Opis:
This paper deals with the optimization of the induction motor design with respect to torque as a dynamical parameter. Most studies on the design of an induction motor using optimization techniques are concerned with the minimization of the motor cost and describe the optimization technique that was employed, giving the results of a single (or several) optimal design(s).Procedure includes the relationship between torque of motor and other effects as they occur in an optimal design. The optimization method that was used in this paper is Differential Evolution as genetic algorithm. Optimal results are in picture as curves or in tabula.
Źródło:
Poznan University of Technology Academic Journals. Electrical Engineering; 2012, 72; 123-128
1897-0737
Pojawia się w:
Poznan University of Technology Academic Journals. Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Dual-Band Compact Integrated Rectenna for Implantable Medical Devices
Autorzy:
Hussein, Shamil H.
Mohammed, Khalid K.
Powiązania:
https://bibliotekanauki.pl/articles/27311860.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
Implantable rectenna
Folded Dipole Antenna FDA
Phantom tissues layers
CST suit
simulation
Opis:
This work describes a dual band compact fully integrated rectenna circuit for implantable medical devices (IMDs). The implantable rectenna circuit consists of tunnel diode 10×10μm2 QW-ASPAT (Quantum Well Asymmetric Spacer Tunnel Layer diode) was used as the RF-DC rectifier due to its temperature insensitivity and nonlinearity compared with conventional SBD diode. SILVACO atlas software is used to design and simulate 100μm2 QW InGaAs ASPAT diode. A miniaturized dual band implantable folded dipole antenna with multiple L-shaped conducting sections is designed using CST microwave suits for operation in the WMTS band is 1.5GHz and ISM band of 5.8GHz. High dielectric constant material Gallium Arsenide (εr=12.94) and folded geometry helps to design compact antennas with a small footprint of 2.84mm3 (1×4.5×0.63) mm3. Four-layer human tissue model was used, where the antenna was implanted in the skin model at depth of 2mm. The 10-dB impedance bandwidth of the proposed compact antenna at 1.5GHz and 5.8GHz are 227MHz (1.4-1.63GHz) with S11 is -22.6dB and 540MHz (5.47-6.02GHz) with S11 is -23.1dB, whereas gains are -36.9dBi, and -24.3dBi, respectively. The output DC voltage and power of the rectenna using two stage voltage doubler rectifier (VDR) are twice that produced by the single stage at input RF power of 10dBm.
Źródło:
International Journal of Electronics and Telecommunications; 2023, 69, 2; 239--245
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study on ultrasound assisted desulfurization of light gas oil using inorganic liquid
Autorzy:
Mahmood, Luma H.
Abid, Mohammad F.
Mohammed, Mohammed I.
Powiązania:
https://bibliotekanauki.pl/articles/207801.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
ultrasounds
desulfurization
light oil
ultradźwięki
odsiarczanie
olej lekki
Opis:
The feasibility of removing sulfur from real light gas oil using inorganic liquids (NaOH, Ca(OH)2 and HCl) at various concentrations assisted with ultrasonication was investigated in a continuous flow setup. Experimental results showed that at the optimum operating time (40 min), 68% of sulfur was removed under mild conditions using 10 wt. % NaOH. Ultrasonication not only facilitated sulfur removal but also improved gas oil properties by decreasing density and viscosity by 1.40 and 4.42%, respectively, while the cetane number (CN) was increased by 7.0%. Solute selectivity (S) depending on sulfur mole fraction (xS) was correlated using StatPlus 6.7.1.0 software and the following values have been obtained: S = 53.869e–2.552xs, and S = 29.573 – 41.878xs for mixtures of 10% Ca(OH)2 + S-compound + oil, and 10% NaOH + S-compound + oil, respectively. The correlation coefficients (R2) for the above equations were 0.9813 and 0.9611, respectively. An empirical correlation related to sulfur removal as a function of processing time and solvent concentration was found with R2 = 0.956. The results of the present work confirmed the feasibility of employing the hybrid method of ultrasonication with using alkaline liquids for sulfur removal.
Źródło:
Environment Protection Engineering; 2019, 45, 4; 5-19
0324-8828
Pojawia się w:
Environment Protection Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Effectiveness of Flipped Classroom on Students’ Performance and Satisfaction in a Biostatistics Course
Autorzy:
Tamimi, Mohammed H.
Khvtisiashvili, Tamrika
Tamimi, Malak B.
Samuh, Monjed H.
Powiązania:
https://bibliotekanauki.pl/articles/2034204.pdf
Data publikacji:
2022-03-31
Wydawca:
Wydawnictwo Adam Marszałek
Tematy:
flipped classroom
university class
alternative-learning methods
Opis:
This paper investigates the effectiveness of the flipped classroom approach on the performance of a group of students in a biostatistics course at Palestine Polytechnic University (PPU). A questionnaire and the class performance are used as the study instruments to evaluate the effectiveness of this approach. The results are compared with another homogeneous group of students using conventional learning. Statistical analysis is carried out to check the significant difference between the two groups. The analysis reveals that the flipped classroom had better class performance and a higher level of satisfaction than conventional learning.
Źródło:
The New Educational Review; 2022, 67; 159-171
1732-6729
Pojawia się w:
The New Educational Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Cancer growth treatment using immune linear quadratic regulator based on crow search optimization algorithm
Autorzy:
Hussein, Mohammed A.
Karam, Ekhlas H.
Habeeb, Rokaia S.
Powiązania:
https://bibliotekanauki.pl/articles/1837793.pdf
Data publikacji:
2021
Wydawca:
Polskie Towarzystwo Promocji Wiedzy
Tematy:
oncolytic virotherapy
feedback mechanism
crow search algorithm
Immune-LQR
wiroterapia onkolityczna
mechanizm sprzężenia zwrotnego
algorytm wyszukiwania w tłumie
Opis:
The rapid and uncontrollable cell division that spreads to surrounding tissues medically termed as malignant neoplasm, cancer is one of the most common diseases worldwide. The need for effective cancer treatment arises due to the increase in the number of cases and the anticipation of higher levels in the coming years. Oncolytic virotherapy is a promising technique that has shown encouraging results in several cases. Mathematical models of virotherapy have been widely developed, and one such model is the interaction between tumor cells and oncolytic virus. In this paper an artificially optimized Immune-Linear Quadratic Regulator (LQR) is introduced to improve the outcome of oncolytic virotherapy. The control strategy has been evaluated in silico on number of subjects. The crow search algorithm is used to tune immune and LQR parameters. The study is conducted on two subjects, S1 and S3, with LQR and Immune-LQR. The experimental results reveal a decrease in the number of tumor cells and remain in the treatment area from day ten onwards, this indicates the robustness of treatment strategies that can achieve tumor reduction regardless of the uncertainty in the biological parameters.
Źródło:
Applied Computer Science; 2021, 17, 2; 56-69
1895-3735
Pojawia się w:
Applied Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Accuracy Assessment of a Variety of GPS Data Processing, Online Services and Software
Autorzy:
Mohammed, Israa H.
Ataiwe, Tariq N.
Al Sharaa, Hisham
Powiązania:
https://bibliotekanauki.pl/articles/1837998.pdf
Data publikacji:
2021
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
online GPS
relative solution
PPP
accuracy assessment
software compariso
Opis:
The processing of GPS observations in precise positioning is complex and requires professional surveyors since it must be carried out after each static measurement. In GPS network adjustment, the obtaining of the correct coordinates of the determined point is possible after determining the components of GPS vectors and aligning the networks of these vectors, while PPP requires the availability of precise products for the reference satellites orbits and clock. For that reason, surveyors can take advantage of free online GPS data processing. In this paper, the authors compare the results obtained from different sources of free online GPS data processing (AUSPOS, OPUS, CenterPoint RTX, APPS, MagicGNSS, CSRS-PPP, GAPS, and SCOUT) in terms of their accuracy, availability, and operation. This is then compared with free GPS processing software (gLAB and RTKLIB), and finally with commercial software (TBC Trimble Business Center). The results show that online processing services are more accurate than offline processing software, which indicates the strength of their algorithms and processes. The CSRS-PPP online service had the best results. The difference between the relative solution of AUSPOS and OPUS, and CSRS-PPP is insignificant.
Źródło:
Geomatics and Environmental Engineering; 2021, 15, 4; 5-19
1898-1135
Pojawia się w:
Geomatics and Environmental Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Prompt gamma-ray methods for industrial process evaluation : a simulation study
Autorzy:
Mohammed, Mohammed Siddig H.
Alhawsawi, Abdulsalam M.
Aljohani, M. S.
Damoom, Mohammed M.
Banoqitah, Essam M.
Elmoujarkach, Ezzat
Powiązania:
https://bibliotekanauki.pl/articles/2105331.pdf
Data publikacji:
2022
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
prompt gamma ray
sealed sources
radiotracers
industrial process
Opis:
Radioisotope applications in industrial process inspection and evaluation using gamma-ray emitters provide otherwise unavailable information. Offering alternative gamma-ray sources can support the technology by complementing sources’ availability and radiation safety. This work proposes to replace gamma-ray from radioisotopes with prompt gamma-ray from the interaction of neutrons with stable isotopes injected into the industrial process or with the structural material of the industrial process equipment. Monte Carlo N-Particle Transport Code (MCNP5) was used to simulate the irradiation of two-phase fl ow pipes by 252Cf neutron source. Two simulations were run for each pipe, with and without mixing the liquid phase with the stable isotope 157Gd. The detected gamma-ray spectra were analysed, and images of the two phases inside the pipes were produced. The images were compared to images obtained from simulations of gamma transmission measurement using 60Co. Furthermore, results for prompt gamma computed tomography (CT) were presented and discussed. The studies’ outcomes indicate the potential of prompt gamma-ray to carry out the sealed sources applications of gamma transmission measurements and imaging.
Źródło:
Nukleonika; 2022, 67, 1; 11--18
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A virtual laboratory for radiotracer and sealed-source applications in industry
Autorzy:
Mohammed, Mohammed Siddig H.
Banoqitah, Essam M.
Elmoujarkach, Ezzat
Alhawsawi, Abdulsalam M.
Djouider, Fathi
Powiązania:
https://bibliotekanauki.pl/articles/1841639.pdf
Data publikacji:
2021
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
sealed sources
radiotracers
industrial gamma tomography
simulation
GATE
Opis:
Radioactive sealed sources and radiotracer techniques are used to diagnose industrial process units. This work introduces a workspace to simulate four sealed sources and radiotracer applications, namely, gamma scanning of distillation columns, gamma scanning of pipes, gamma transmission tomography, and radiotracer fl ow rate measurements. The workspace was created in Geant4 Application for Tomographic Emission (GATE) simulation toolkit and was called Industrial Radioisotope Applications Virtual Laboratory. The fl exibility of GATE and the fact that it is an open-source software render it advantageous to radioisotope technology practitioners, educators, and students. The comparison of the simulation results with experimental results that are available in the literature showed the effectiveness of the virtual laboratory.
Źródło:
Nukleonika; 2021, 66, 1; 21-27
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Linear and Planar Array Pattern Nulling via Compressed Sensing
Autorzy:
Mohammed, Jafar Ramadhan
Thaher, Raad H.
Abdulqader, Ahmed Jameel
Powiązania:
https://bibliotekanauki.pl/articles/1839322.pdf
Data publikacji:
2021
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
compressed sensing
convex optimization
iterative re-weighted l1- norm minimization
linear array
planar array
Opis:
An optimization method based on compressed sensing is proposed for uniformly excited linear or planar antenna arrays to perturb excitation of the minimum number of array elements in such a way that the required number of nulls is obtained. First, the spares theory is relied upon to formulate the problem and then the convex optimization approach is adopted to find the optimum solution. The optimization process is further developed by using iterative re-weighted l1- norm minimization, helping select the least number of the sparse elements and impose the required constraints on the array radiation pattern. Furthermore, the nulls generated are wide enough to cancel a whole specific sidelobe. Simulation results demonstrate the effectiveness of the proposed method and the required nulls are placed with a minimum number of perturbed elements. Thus, in practical implementations of the proposed method, a highly limited number of attenuators and phase shifters is required compared to other, conventional methods.
Źródło:
Journal of Telecommunications and Information Technology; 2021, 3; 50-55
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
THE EFFECT OF A SINGLE OR MULTIPLE DOSES OF GRAPEFRUIT JUICE ON SOME PHARMACOKINETIC AND PHARMACODYNAMIC EFFECTS OF PARACETAMOL IN MICE
Autorzy:
AL ZA'ABI, MOHAMMED
ALI, BADRELDIN H.
AL-HDHRAMI, ASMA
Powiązania:
https://bibliotekanauki.pl/articles/895589.pdf
Data publikacji:
2019-08-30
Wydawca:
Polskie Towarzystwo Farmaceutyczne
Tematy:
mice
paracetamol
pharmacokinetic
grapefruit juice
pharmacodynamic
Opis:
Grapefruit juice (GFJ), a commonly consumed dietary substance, has been shown to alter the disposition of several commonly used drugs. The available data on the effects of GFJ on the paracetamol pharmacokinetics and pharmacodynamics are at variance. The aim of this study was to evaluate the effect of a single or multiple dose of GFJ on some pharmacokinetics and pharmacodynamics aspects of orally given paracetamol (400 mg/Kg). Male mice were randomly divided into three equal groups: mice in the first group were given paracetamol; the second group was given a single oral dose (10 mL/Kg) of GFJ one hour prior to paracetamol administration; the third group was administered multiple oral doses of GFJ (10 mL/Kg) for five consecutive days, and on the last day it was treated with paracetamol. Blood samples were collected 10, 20, 30, and 40 min, and 1, 2, 4, 6 and 8 h after paracetamol administration for subsequent pharmacokinetic analysis. Some mice in the same three groups were also tested for their reactions to thermal (hotplate) and chemical (acetic acid induced – abdominal constriction) nociceptive stimuli. GFJ increased the plasma concentration and area under the plasma concentration curve of paracetamol, to a greater extent after a single dose than multiple doses. It also increased the reaction time in the hotplate test, and reduced abdominal constrictions. GFJ administration increased the plasma concentration and the analgesic effect of paracetamol in mice. The possible implications of these changes in humans and their clinical relevance need to be further investigated.
Źródło:
Acta Poloniae Pharmaceutica - Drug Research; 2019, 76, 4; 753-759
0001-6837
2353-5288
Pojawia się w:
Acta Poloniae Pharmaceutica - Drug Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Vein Biometric Recognition Methods and Systems: A Review
Autorzy:
Al-Khafaji, Ruaa S.S.
Al-Tamimi, Mohammed S.H.
Powiązania:
https://bibliotekanauki.pl/articles/2022496.pdf
Data publikacji:
2022
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
biometric technology
finger vein recognition
pre-processing
feature extraction
matching
Opis:
The Finger-vein recognition (FVR) method has received increasing attention in recent years. It is a new method of personal identification and biometric technology that identifies individuals using unique finger-vein patterns, which is the first reliable and suitable area to be recognized. It was discovered for the first time with a home imaging system; it is characterized by high accuracy and high processing speed. Also, the presence of patterns of veins inside one’s body makes it almost difficult to repeat and difficult to steal. Based on the increased focus on protecting privacy, that also produces vein biometrics safer alternatives without forgery, damage, or alteration over time. Fingerprint recognition is beneficial because it includes the use of low-cost, small devices which are difficult to counterfeit. This paper discusses preceding finger-vein recognition approaches systems with the methodologies taken from other researchers’ work about image acquisition, pretreatment, vein extraction, and matching. It is reviewing the latest algorithms; continues to critically review the strengths and weaknesses of these methods, and it states the modern results following a key comparative analysis of methods.
Źródło:
Advances in Science and Technology. Research Journal; 2022, 16, 1; 36-46
2299-8624
Pojawia się w:
Advances in Science and Technology. Research Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Enhancement of thermal efficiency of nanofluid flows in a flat solar collector using CFD
Autorzy:
Zarda, Falah
Hussein, Adnan Mohammed
Danook, Suad H.
Mohamad, Barhm
Powiązania:
https://bibliotekanauki.pl/articles/2146747.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Polskie Towarzystwo Diagnostyki Technicznej PAN
Tematy:
solar collector flat-plate
diamond/H2O nanofluids
thermal performance
computational fluid dynamics
płaski kolektor słoneczny
właściwości cieplne
numeryczna mechanika płynów
Opis:
Flat plate solar collector (FPSC) is popular for their low cost, simplicity, and ease of installation and operation. In this work, FPSC thermal performance was analyzed. It's compared to diamond/H2O nanofluids. The volume percentage and kind of nanoparticles are analyzed numerically that validation with experimental data available in the literature. The hot climate of Iraq is employed to approximate the model. The numerical study is performed by using ANSYS/FLUENT software to simulate the case study of problem. Due to less solar intensity after midday, temperatures reduction. The greatest collector thermal efficiency is 68.90% with 1% ND/water nanofluid, a 12.2% increase over pure water. The efficiency of 1% nanofluid is better than other concentrations because of a change in physical properties and an increase in thermal conductivity. Since the intensity of radiation affects the outlet temperature from the solar collector and there is a direct link between them, this increases the efficiency of the solar collector, especially around 12:30 pm at the optimum efficiency.
Źródło:
Diagnostyka; 2022, 23, 4; art. no. 2022411
1641-6414
2449-5220
Pojawia się w:
Diagnostyka
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical and experimental modelling of slope stability and seepage water of earthfill dam
Autorzy:
El-Hazek, Alaa N.
Abdel-Mageed, Neveen B.
Hadid, Mohammed H.
Powiązania:
https://bibliotekanauki.pl/articles/947129.pdf
Data publikacji:
2020
Wydawca:
Instytut Technologiczno-Przyrodniczy
Tematy:
earthfill dam
finite element modelling
GeoStudio
seepage
slope stability
Opis:
In this paper, finite element modelling is employed for simulating and analysing seepage and slope stability of earthfill dam via GeoStudio software. Two products are employed, which are SLOPE/W for slope stability and SEEP/W for seepage analysis. The behaviour of earthfill dam with four different types of sandy soils having different values of hydraulic conductivity (K) has been studied. Different upstream (US) slopes of 1:2, 1:2.5, 1:3 and 1:3.5 for the earthfill dam are simulated. The downstream (DS) slope is constant at 1:2. The results showed for all the four types of soils that when the US slope is increased, the amount of seepage from the dam increases and the factor of safety (F) decreases. For each US slope, when K (type of soil) increases, both seepage and F increase. Fine sand soil is associated with less seepage and less F. Sixteen equations are obtained to predict both seepage and F with respect to US slope for each type of soil and K of the soil for US slope. An experimental model for earthfill dam is constructed in the laboratory of hydraulics, Benha University to investigate the seepage of water through earthfill dams. It is concluded that seepage decreased when K decreased, and when the US slope for each type of soil decreased. The seepage increased when K increased for each US slope. Seven equations are obtained to predict seepage with respect to US slope for each type of soil, and K for each US slope.
Źródło:
Journal of Water and Land Development; 2020, 44; 55-64
1429-7426
2083-4535
Pojawia się w:
Journal of Water and Land Development
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
Wyświetlanie 1-15 z 34

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