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排序方式: 共有138条查询结果,搜索用时 125 毫秒
1.
Amino acid germanate compounds are synthesized by the chemical reaction of germanium dioxide with a selected amino acid in the presence of an alkali medium at a suitable elevated temperature. Amino acids included in the novel synthesis include histidine, methionine and glutathione. The study evaluated their effects on induction of interleukin-12 and interferon-γl in Swiss albino Webster rats. The new germanium compounds, especially bis-methionino germanate, are considered as good interferon inducer that significantly enhance the immunologic function. 相似文献
2.
M. M. Hafiz N. Afify M. A. Osman M. Dongol 《Journal of Thermal Analysis and Calorimetry》1990,36(7-8):2417-2426
The crystallization kinetics of the chalcogenide glass Se0.8Te0.2 was studied by means of differential scanning calorimetry. The variation in partial area (X) with temperature (T) revealed that the transition from the amorphous to the crystalline phase occurs in two dimensions.Activation energies were determined for both the glass transition (E
t) and the crystallization (E
c).E
t was calculated from the variation inT
g with the heating rate (a).E
c was determined by three different methods: (i) variation inX withT, (ii) variation inT
p
witha, and (iii) variation inT
c witha.E
t andE
c have values of 161.01±2.75 and 84.75 ±8.21 kJ/mol, respectively.
This work was partly supported by a Grant-in-Aid for Scientific Research from the GTZ GmbH and DAAD, W. Germany. 相似文献
Zusammenfassung Mittels DSC wurde die Kristallisierungskinetik des Chalkogenidglases Se0.8Te0.2 untersucht. Eine Änderung partieller Gebiete (X) mit der Temperatur (T) zeigte, daß der Übergang von der amorphen zur kristallinen Phase zweidimensional verläuft.Es wurde die Aktivierungsenergie sowohl für den Glasübergang (E t) als auch für die Kristallisierung (E c) bestimmt.E t wurde mittels der Abhängigkeit vonT g von der Aufheizgeschwindigkeit (a) ermittelt.E c wurde auf drei verschiedene Wege bestimmt: (i) Änderung vonX in Abhängigkeit vonT, (ii) Änderung vonT p in Abhängigkeit vona und (iii) Änderung vonT c in Abhängigkeit vona. Die Werte vonE t undE c betragen 161.01±2.75 bzw. 84.75±8.21 kJ/mol.
This work was partly supported by a Grant-in-Aid for Scientific Research from the GTZ GmbH and DAAD, W. Germany. 相似文献
3.
Hafiz Saqib Ali Dr. Richard H. Henchman Dr. Sam P. de Visser 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(57):13093-13102
A recently characterized cytochrome P450 isozyme GcoA activates lignin components through a selective O-demethylation or alternatively an acetal formation reaction. These are important reactions in biotechnology and, because lignin is readily available; it being the main component in plant cell walls. In this work we present a density functional theory study on a large active site model of GcoA to investigate syringol activation by an iron(IV)-oxo heme cation radical oxidant (Compound I) leading to hemiacetal and acetal products. Several substrate-binding positions were tested and full energy landscapes calculated. The study shows that substrate positioning determines the product distributions. Thus, with the phenol group pointing away from the heme, an O-demethylation is predicted, whereas an initial hydrogen-atom abstraction of the weak phenolic O-H group would trigger a pathway leading to ring-closure to form acetal products. Predictions on how to engineer P450 GcoA to get more selective product distributions are given. 相似文献
4.
Abdel-Nour Zaim Aissa Abderrahmane Mebarek-Oudina Fateh Rashad A. M. Ali Hafiz Muhammad Sahnoun M. El Ganaoui M. 《Journal of Thermal Analysis and Calorimetry》2020,141(5):1981-1992
Journal of Thermal Analysis and Calorimetry - The effect on the entropy production and MHD convection of the hybrid nanofluid Al2O3–Cu/water (water with Cu and Al2O3 nanoparticles) in a... 相似文献
5.
Solid state bio-processing of wheat straw was carried out through an indigenous fungal strain Pleurotus ostreatus IBL-02 under pre-optimized fermentation conditions. The maximum activity, 692±12 U/mL, of the industrially important manganese peroxidase (MnP) enzyme was recorded after five days of still culture incubation. The crude MnP was 2.1-fold purified with a specific activity of 860 U/mg after purification on a Sephadex-G-100 gel column. On native and SDS-PAGE electrophoresis gels, the purified MnP fraction was a single homogenous band of 45 kDa. An active fraction of MnP was immobilized using hydrophobic sol-gel entrapment comprising tetramethoxysilane (T) and propyltrimethoxysilane (P) at different T:P molar ratios. Characterization revealed that after 24 h incubation at varying pH and temperatures, the MnP fraction immobilized at a T:P ratio of 1:2 in the sol-gel retained 82% and 75% of its original activity at pH4 and 70 ℃, respectively. The optimally active fraction at a 1:2 T:P ratio was tested against MnSO4 as a substrate to determine the kinetic catalytic constants KM and Vmax . To explore the industrial applicability of P. ostreatus IBL-02 MnP, both the free and immobilized MnP were used for the decolorization of four different textile industrial effluents. A maximum of 100% decolorization was achieved for the different textile effluents within the shortest time period. A lower KM , higher Vmax , hyper-activation, and enhanced acidic and thermal resistance up to 70 ℃ were the novel catalytic features of the sol-gel immobilized MnP, suggesting that it may be a potential candidate for biotechnological applications particularly for textile bioremediation purposes. 相似文献
6.
Hafiz Muhammad Bilal Ameer Muhammad Faizan Ameer Kaouther Ghachem Muhammad Ali Ahsan Razaq Sami Ullah Khan Muhammad Hamza Lioua Kolsi 《印度化学会志》2022,99(6):100505
The environmental degradation, combined with the continuous depletion of the world's fossil fuel reserves, has forced the search for alternative fuels. This study was performed to investigate the performance of novel biodiesels in the CI engine. The experiments were performed at three different compressions ratios (16:1, 17:1, 18:1) and four loading conditions (25%, 50%, 75%, 100%). Different types of fuels such as jatropha biodiesel (JB), roselle biodiesel (RB), and ternary biodiesel (TB) were prepared and analyzed. The thermal performance of different fuels was analyzed in terms of brake thermal efficiency (BTE), brake specific fuel consumption (BSFC), and exhaust gas temperature (EGT). The emission characteristics such as CO2 emission, NOx emission, and smoke emission were analyzed for all types of fuels. The results of these fuels in the engine were compared with mineral diesel (MD). The BTE was increased with increasing compression ratios and loads for all types of fuels. The BSFC was increased with increasing compression ratios but decreased with increasing loads. The increase in emission of NOx was observed at higher compression ratios and loads. However, the CO2 emission was decreased at higher loads and lower compression ratio. The performance curves achieved with a 20% jatropha biodiesel blend showed results that were approximate to those obtained with pure MD. The comparative analysis between different fuels showed that JB exhibit higher thermal performance as compared to other biodiesels. Therefore, JB can be a better alternative to conventional fuel. 相似文献
7.
Qamar Adnan Anwar Zahid Ali Hassan Shaukat Rabia Imran Shahid Arshad Attique Ali Hafiz Muhammad Korakianitis Theodosios 《Journal of Thermal Analysis and Calorimetry》2022,147(1):23-46
Journal of Thermal Analysis and Calorimetry - Nanofluids have recently attracted attention of many researchers due to their growing potential applications in heat transfer devices. They possess... 相似文献
8.
Sadeghi Mohamad Sadegh Anadalibkhah Naghmeh Ghasemiasl Ramin Armaghani Taher Dogonchi Abdul Sattar Chamkha Ali J. Ali Hafiz Asadi Amin 《Journal of Thermal Analysis and Calorimetry》2022,147(1):1-22
Journal of Thermal Analysis and Calorimetry - The ultimate goal of the present review paper is to summarize and discuss the findings of the most recently published literature on natural convection... 相似文献
9.
Syam Sundar L. Misganaw A. H. Singh Manoj K. Sousa António C. M. Ali Hafiz Muhammad 《Journal of Thermal Analysis and Calorimetry》2021,143(2):959-972
Journal of Thermal Analysis and Calorimetry - In the present study, the thermal efficiency, convective heat transfer and friction factor analysis are investigated for a flat plate solar collector... 相似文献
10.
Janjua Muhammad M. Khan Najeeb U. Khan Waqar A. Khan Waseem S. Ali Hafiz Muhammad 《Journal of Thermal Analysis and Calorimetry》2021,143(3):2039-2052
Journal of Thermal Analysis and Calorimetry - The thermal performance of an isothermal horizontal cylinder with different selected cross sections in cross-flow was investigated numerically. These... 相似文献