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排序方式: 共有988条查询结果,搜索用时 388 毫秒
51.
52.
Bhattacharya Sandip Ajayan J. D.Nirmal Tayal Shubham Kollem Sreedhar Joseph L. M. I. Leo 《SILICON》2022,14(15):9581-9588
Silicon - The RF/DC performances of LG = 19 nm heterogeneous integrated Ga0.15In0.85As/InAs/Ga0.15In0.85As composite channel based InP HEMT (high electron mobility transistor)... 相似文献
53.
Novel two pack polyurethane wood finished coatings are prepared from renewable sources, such as vegetable oil based fatty acid and dimer fatty acid. In actual experimental part oleic acid was reacted with diethanolamine to obtain amide which was on condensation polymerization with dimer fatty acid converted into the polyesteramide polyol. These are all being used to prepare polyurethanes. The functional and structural elucidation of dimer fatty acid based polyesteramide and diethanolamide were carried out by end group analysis, spectral studies such as FTIR and 1H NMR. Average molar masses of the polyesteramide were estimated by gel permeation chromatography (GPC). The polyesteramide was used in the preparation of wood finished polyurethane coatings by reacting it with aromatic diisocyanates. Thermogravimetric analysis (TGA) was used to study the thermal behavior of coatings. Physico-chemical and coating properties of the coatings were investigated by using standard methods. The results indicated that the bio-based wood finished PU coatings provided good mechanical, weather resistance as well possessed adequate coating properties for wood surface protections. 相似文献
54.
Sandip B. Bankar Mahesh V. Bule Rekha S. Singhal Laxmi Ananthanarayan 《Food and Bioprocess Technology》2009,2(4):344-352
A number of nutritional factors influencing glucose oxidase (EC 1.1.3.4) production by Aspergillus niger NCIM 545 were studied. The synthesis of glucose oxidase by A. niger was investigated in two steps using submerged fermentation at 30 ± 2 °C and 180 rpm for 96 h. Primarily, nutritional components
were selected by one-factor-at-a-time method, and the significance of each component with respect to glucose oxidase production
was identified by Plackett–Burman design (seven variables including six nutritional viz. sucrose, sodium nitrate, peptone,
calcium carbonate, magnesium sulfate, and potassium dihydrogen phosphate, and one dummy or unassigned variable were studied
with eight experiments). In the second step, concentration of most significant factors and their interaction were studied
with response surface methodology (central composite design). Each variable in the design was studied at five different levels,
with all variables taken at a central coded value of zero. Considerable amount of glucose oxidase was produced from A. niger species with sucrose as the carbon source, sodium nitrate as the inorganic nitrogen source, and peptone as the organic nitrogen
source. Glucose oxidase activity increased remarkably by 28.93 fold (from 0.00993 to 0.29 U ml−1) with CaCO3-supplemented media. The outcome of Plackett–Burman design showed CaCO3, peptone, and MgSO4 as significant parameters. Further optimization using a three-factor central composite design with 20 experiments increased
yield of glucose oxidase from 0.29 to 2.05 U ml−1 (sevenfold) with a decrease in cultivation time from 96 to 72 h. 相似文献
55.
Anoop K. Mukhopadhyay Keshaw D. Joshi Arjun Dey Riya Chakraborty Ashok K. Mandal Amit Rav Jiten Ghosh Sandip Bysakh Sampad K. Biswas Satish C. Gupta 《Ceramics International》2011,37(7):2365-2376
Shock recovered samples of a coarse grain (10 μm), high density (>99.9% theoretical) alumina from asymmetric impact tests conducted at 6.5 GPa (e.g. 3.2 times its Hugoniot Elastic Limit) in a single stage gas gun and characterized by X-ray diffractometry, scanning and field emission scanning electron microscopy, and transmission electron microscopy showed prolific presence of reduced crystallite size, higher average microstrain, grain localized micro/nano-scale deformations, micro-cleavages, grain-boundary microcracks, micro-wing crack formation, extensive shear induced deformations and fractures localized at grains, grain boundaries and triple grain junctions, grain localized entanglement of dislocations and their pile up impeded at grain boundaries. A new qualitative model based on micro-shear and micro-twist induced deformation and fracture in single and/or multiple planes in suitably oriented grain and/or grain assembly was developed to explain the experimentally observed damage evolution process. 相似文献
56.
57.
In this work, we report a green method for the synthesis of gold nanoparticles (GNP) using the aqueous extract of red tomato (Lycopersicon esculentum). We believe that citric acid and ascorbic acid present in tomato juice are responsible for the reduction of gold ions. This biosynthesized GNP in the presence of sodium dodecyl sulfate has been used as a colorimetric sensor to detect and estimate the pesticide, methyl parathion. The GNP in the presence of methyl parathion shows a new peak at 400 nm due to the formation of 4-nitrophenolate ion by catalytic hydrolysis of methyl parathion in alkaline medium. A calibration curve between the absorption coefficients of the 400-nm peak versus the concentration of the pesticide allows the quantitative estimation of the 4-nitrophenolate ion, thereby enabling indirect estimation of methyl parathion present in the system. 相似文献
58.
Amit Kumar Maity Kalipada Maity Shyamal Kumar Mondal Manoranjan Maiti 《Optimization and Engineering》2009,10(3):427-438
This paper develops an integrated production-recycling system over a finite time horizon. Here, the dynamic demand is satisfied
by production and recycling. The used units are bought back and then either recycled or disposed of which are not repairable.
The used units are collected continuously from the customers. Recycling products can be used as new products which are sold
again. The rate of production and disposal are assumed to be function of time. The setup cost is reduced over time due to
“Learning curve” effect. The optimum results are presented both in tabular form and graphically. 相似文献
59.
Polythiophene thin films were deposited successfully on glass substrate by chemical bath deposition method using FeCl3 as an oxidant and chloroform as solvent. The effect of oxidant concentration on the properties of polythiophene thin films was studied. The surface morphology was influenced by oxidant concentration and deposition time. The oxidation concentration also strongly affects the optical properties of the polythiophene thin films. The transmittance decreases while the absorption, band gap and refractive index increases due to increase in oxidant concentration. 相似文献
60.
In this paper, a new approach for extracting stress intensity factors (SIFs) by the extended element-free Galerkin method, through a crack closure integral (CCI) scheme, is proposed. The CCI calculation is used in conjunction with a local smoothing technique to improve the accuracy of the computed SIFs in a number of case studies of linear elastic fracture mechanics. The cases involve problems of mixed-mode, curved crack and thermo-mechanical loading. The SIFs by CCI, displacement and stress methods are compared with those based on the M-integral technique reported in the literature. The proposed CCI method involves very simple relations, and still gives good accuracy. The convergence of the results is also examined. 相似文献