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41.
Mahesh Chandra Alok Kalra Pradeep K. Sharma Hirdesh Kumar Rajinder S. Sangwan 《Biomass & bioenergy》2010,34(5):805-811
The production of cellulases by Trichoderma citrinoviride fermented on marc of Artemisia annua, and bioconversion of the same marc by produced cellulase system was studied. The effects of pretreatments, substrate concentration, particle size, initial pH, temperature and concentration of the medium components on production of FPase, endoglucanase and β-glucosidase were monitored and comparatively evaluated. Among the three pretreatment processes, alkali hydrolysis with autoclaving was found to be most suitable for production of all the three enzymes. Optimum production of FPase, endoglucanase and β-glucosidase was obtained at 96 h, 96 h and 72 h of fermentation period, respectively. Substrate concentration of 1% with particle size between 200 μm and 475 μm gave the higher yields. Higher production of all the three enzymes was obtained with initial pH value of 5.5, temperature of 28 °C and 75% of mineral salt solution. Partially purified enzyme system obtained by optimized fermentation procedure, was applied for saccharification. Forty six percent of saccharification was noticed after 48 h of incubation on alkali hydrolyzed and autoclaved substrate which was 3.26 fold more than that of unpretreated substrate. 相似文献
42.
Alok K. Hazra Somiranjan Ghosh Shivaji Banerjee Biswapati Mukherjee 《Journal of the American Oil Chemists' Society》1998,75(11):1673-1678
The puffer fishes Chelonodon patoca, Sphaeroides oblongus, Lagocephalus lunaris, and L. inermis of Indian coastal waters are wasted in huge quantity. The livers of these fishes were investigated for their lipid contents
and fatty acid compositions in different seasons. It was found that monsoon season is the suitable time to obtain the maximal
lipids (40.1–48.8%) from their livers, an amount similar to cod liver lipid content (39.5–55.0%). The fatty acids were mostly
saturates and monoenes (60–70%). Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) concentrations (7–12%) were high
during monsoon season. Neutral lipids were the predominant lipid class (>80%) and comprised triglycerides (277–674 mg/g) and
cholesterol (0.6–3.1 mg/g). Quality indices of puffer liver lipids, e.g., specific gravity, refractive index, acid value,
iodine value, saponification value and unsaponifiable matter, were evaluated. Puffer liver lipids were quantitatively and
qualitatively comparable to other commercially important marine fish oils. The overall study suggests the possibility of future
commercial utilization of liver lipids from puffer, an unconventional, cheap, and easily available source. 相似文献
43.
Singh Prakash K. Rajak P. K. Singh M. P. Singh V. K. Naik A. S. Singh Alok K. 《国际煤炭科学技术学报(英文)》2016,3(2):148-164
International Journal of Coal Science & Technology - The lignite samples collected from Giral lignite field of Barmer basin have been subjected to petrological investigation. The data generated... 相似文献
44.
45.
Alok Warey Sandro Balestrino Pat Szymkowicz M. R. Malayeri 《Aerosol science and technology》2013,47(2):198-213
Cooled exhaust gas recirculation (EGR) is widely used in diesel engines to control engine out NOx (oxides of nitrogen) emissions. A portion of the exhaust gases is recirculated into the intake manifold of the engine after cooling it through a heat exchanger. EGR cooler heat exchangers, however, tend to lose efficiency and have increased pressure drop as deposit forms on the heat exchanger surface. This adversely affects the combustion process, engine durability, and emissions. In this study, a 1-D model was developed to simulate soot deposition, soot removal, and condensation of several hydrocarbon (HC) species in a circular tube with turbulent gas flow at constant wall temperature. The circular tube, which makes up the computational domain in the model, represents a single channel from any EGR cooler geometry. The model takes into account soot particle deposition due to thermophoresis, diffusion, turbulent impaction, and gravitational drift. However, thermophoresis was found to be the most dominant deposition mechanism for boundary conditions at which EGR coolers typically operate. Soot removal was modeled by considering a force balance between the drag and van der Waals forces. A lognormal distribution of particles was assumed at the tube inlet. The evolution of the particle distribution in the bulk flow along the tube as well as the mass distribution in the deposit layer on the tube walls is predicted by the model. Condensation of six HC species between C15-C24 alkanes was also modeled. Predictions made by the model are in reasonably good agreement with experimental data obtained from a laboratory reactor under the same boundary conditions. There are several assumptions and simplifications built into the model, which can be refined further to improve it. Copyright 2012 American Association for Aerosol Research 相似文献
46.
In this work, we report electronic structure calculations aimed at computing the linear optical absorption spectrum and static
dipole polarizablity of a newly proposed boron-based planar aromatic compound borozene (B
12
H
6). For the purpose, we use the semiempirical INDO model Hamiltonian, accompanied by large-scale correlation calculations using
the multi-reference singles-doubles configuration-interaction (MRSDCI) approach. We present detailed predictions about the
energetics, polarization properties, and the nature of many-particle states contributing to various peaks in the linear absorption
spectrum. Our results can be used to characterize this material in future optical absorption experiments. We also argue that
one can deduce the aromaticity of the cluster from the optical absorption and static polarizability results. 相似文献
47.
Alok Kumar Rai N. K. Singh Sang-Kwon Lee K. D. Mandal D. Kumar Om Parkash 《Journal of Materials Science: Materials in Electronics》2011,22(9):1286-1289
Dielectric properties of iron doped CaCu3Ti4O12 (CCTO), viz. CaCu3Ti3.9Fe0.1O12 (CCTFO) prepared by a novel semi-wet route have been investigated. X-ray diffraction of powder sintered at 900 °C show formation
of single phase solid solution. Energy dispersive X-ray spectroscopy (EDX) confirmed the presence of CuO rich phase at grain
boundaries of CCTFO. Nature of dielectric relaxation observed above room temperature is studied using complex plane impedance
analysis and modulus spectroscopy. It has been found that out of the two relaxations reported earlier above room temperature,
one occurring at lower temperature is due to grainboundaries interfacial polarization. 相似文献
48.
Hidetoshi Somekawa Tadanobu Inoue Alok Singh Toshiji Mukai 《Metallurgical and Materials Transactions A》2011,42(8):2475-2480
The deformation mechanism in the crack-tip region of a fine-grained Mg-2.4 at. pct Zn binary alloy was investigated by focused
ion beam (FIB) and transmission electron microscopy (TEM) observation and finite element analysis (FEA) at the beginning of
the fracture toughness test. The deformed microstructure observations showed the formation of subgrains instead of deformation
twins in the fracture toughness tested sample, which was performed at a conventional crosshead speed of 1 mm/min. By preventing
the formation of deformation twins at the beginning of the test, the crack tip of the fine-grained magnesium alloys became
blunted, and thus, the alloys obtained high fracture toughness. Finite element results showed that the temperature increased
50 to 110 K, and the strain rate became two orders of magnitude higher; however, this temperature increment was not sufficient
to form high-angle grain boundaries, i.e., a complete occurrence of dynamic recrystallization. On the other hand, the deformed microstructure observations in the sample,
which was tested at a crosshead speed of 50 mm/min, showed the formation of nano-order {10-12} deformation twins and subgrains.
The formation of deformation twins was caused, in part, by the severe strain from the operation of a high strain rate in the
crack-tip region. 相似文献
49.
Alok Gupta Boris Jukic Mingzhi Li Dale O. Stahl Andrew B. Whinston 《Computational Economics》2001,17(2-3):203-218
We investigate two parametric approaches and one non-parametric approach toestimating Internet users' value-of-time, an important characteristic ofdemand for Internet services. The advantages of these approaches are madeclear and their limitations discussed. The models are tested with datagenerated from our similation model of the Internet economy. Given thecharacteristics of the data, we investigate parametric count-data modelsfirst. While reasonably good results are obtained on all medium- andlarge-sized jobs, the method fails on small-sized ones. Second, we develop anonparametric quasi-Bayesian update algorithm for retrieving the underlyingdistribution function of Internet users' value-of-time purely fromobservations on their choices. Compared with the parametric count-data models,good results are obtained in every case. 相似文献
50.
Alok Choudhury 《真空研究与实践》1990,2(2):114-120
The growing demands for better quality of metallic materials can only be met by the application of vacuum during the production of these metals and alloys and their field of application. 相似文献