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21.
Md Faisal Md Basir Muhammad Bilal Rakesh Choudhary Joby Mackolil B. Mahanthesh Kottakkaran S. Nisar 《亚洲传热研究》2021,50(6):5439-5466
The impact of Stefan blowing on the MHD bioconvective slip flow of a nanofluid towards a sheet is explored using numerical and statistical tools. The governing partial differential equations are nondimensionalized and converted to similarity equations using apposite transformations. These transformed equations are solved using the Runge–Kutta–Fehlberg method with the shooting technique. Graphical visualizations are used to scrutinize the effect of the controlling parameters on the flow profiles, skin friction coefficient, local Nusselt, and Sherwood number. Moreover, the sensitivities of the reduced Sherwood and Nusselt number to the input variables of interest are explored by adopting the response surface methodology. The outcomes of the limiting cases are emphatically in corroboration with the outcomes from preceding research. It is found that the heat transfer rate has a positive sensitivity towards the haphazard motion of the nanoparticles and a negative sensitivity towards the thermomigration. The thermal field is enhanced by the Stefan blowing aspect. Moreover, the fluid velocity can be controlled by the applied magnetic field. 相似文献
22.
23.
Dominik Rätz Kelly A. Jordan Gregory Perret Rakesh Chawla 《Annals of Nuclear Energy》2011,38(11):2319-2332
Two different types of perturbations of an SCWR-like fuel lattice have been investigated experimentally in the central test zone of the PROTEUS zero-power research reactor at the Paul Scherrer Institute in Switzerland. In each case, a campaign of high-resolution gamma-ray spectroscopy measurements was carried out on 34 fuel pins of the test lattice. In the first case, the test lattice was perturbed by inserting aluminum rods into the four central moderator regions, while in the second case, the perturbation was affected using steel absorber rods (instead of aluminum). The derived reaction rates are the capture rate in 238U (C8) and the total fission rate (Ftot), as also the reaction rate ratio C8/Ftot. Each of these has been mapped on the lattice and compared to calculated results from whole-reactor Monte Carlo simulations with MCNPX. Excellent agreement has been obtained, for both perturbed lattices, between the calculated and experimental distributions of C8, Ftot and C8/Ftot. Considering that control rods in an SCWR assembly are foreseen to be inserted into the central moderator regions, these results may be considered as generic validation of Monte Carlo simulations for the two different types of lattice perturbations which inserted control rods imply, viz. moderator displacement and strong neutron absorption.In a second step, calculated C8, Ftot and C8/Ftot distributions for the two perturbed lattices (as well as for the unperturbed lattice) have been compared, at assembly level, between MCNPX and the deterministic LWR lattice code CASMO-4E. In the case of the unperturbed lattice, as well as for the lattice with steel rods, the agreement between the codes is found to be within ~1% for all pins and each reaction rate. However, for the lattice with aluminum rods, i.e. the case with mainly just moderator displacement involved, CASMO overestimates the reaction rates in the vicinity of the perturbations by up to 2–3%, when employing the standard input options. The reason for this discrepancy has been found to be the leakage treatment, which uses the fundamental-mode buckling applied in a homogenized sense across the lattice. In this way, global leakage gradients get averaged out over the entire assembly. The optional input card BZ2 for CASMO resolves this problem, and the codes then agree within 1% even for the aluminum case. 相似文献
24.
Aminolytic chemical recycling is performed for obtaining NN′ diethyl 1,4 benzene dicarboxamide, NN′ dibutyl 1,4 benzene dicarboxamide, and NN′ dihexyl 1,4 benzene dicarboxamide from Polyethylene terephthalate bottle waste. The compounds were characterized through Fourier transform Infrared spectroscopy, Raman spectroscopy, UV–Visible spectroscopy, 1H NMR, 13C NMR, mass spectrometry, and elemental analysis. Thermal properties were also analyzed with the help of thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Density Functional Theory (DFT) study has been performed at GGA-BLYP (Becke's and Lee–Yang–Parr) functional using SZ basis set to investigate the vibrational frequencies and physical parameters. Experimental vibrational frequencies were found in good accord with the experimental values. Calorific values of the products have been determined using bomb calorimeter as per standard ASTM D240. The values have been correlated with increment of methylene units from NN′ diethyl BdCA to NN′ dihexyl BdCA using standard molar enthalpies of carbon and hydrogen. SEM and EDX analysis of the char residues after combustion has also been carried out to insight the effect of N-alkyl chain length on calorific values. The calorific values of the recovered compounds are comparable to commercial solid fuels and the compounds may find potential applications in aerospace industry. 相似文献
25.
Rakesh K. Upadhyay Marvin Edelman Autar K. Mattoo 《International journal of molecular sciences》2020,21(24)
Lipoxygenases (LOXs) (EC 1.13.11.12) catalyze the oxygenation of fatty acids and produce oxylipins, including the plant hormone jasmonic acid (JA) and its methyl ester, methyl jasmonate (MeJA). Little information is available about the LOX gene family in aquatic plants. We identified a novel LOX gene family comprising nine LOX genes in the aquatic plant Spirodela polyrhiza (greater duckweed). The reduced anatomy of S. polyrhiza did not lead to a reduction in LOX family genes. The 13-LOX subfamily, with seven genes, predominates, while the 9-LOX subfamily is reduced to two genes, an opposite trend from known LOX families of other plant species. As the 13-LOX subfamily is associated with the synthesis of JA/MeJA, its predominance in the Spirodela genome raises the possibility of a higher requirement for the hormone in the aquatic plant. JA-/MeJA-based feedback regulation during culture aging as well as the induction of LOX gene family members within 6 h of salt exposure are demonstrated. 相似文献
26.
Palit Piyas Kushwaha Sanjay Kumar Mathur Jitendra Chaturvadi Abhay Kumar 《Journal of Failure Analysis and Prevention》2019,19(3):752-760
Journal of Failure Analysis and Prevention - Wire rope is an important part of any crane. Failure of wire rope may lead to major loss in terms of life and cost. Wire rope failures are attributed by... 相似文献
27.
Removal of lead from aqueous solution using Syzygium cumini L.: equilibrium and kinetic studies 总被引:1,自引:0,他引:1
King P Rakesh N Beenalahari S Prasanna Kumar Y Prasad VS 《Journal of hazardous materials》2007,142(1-2):340-347
The biosorption of lead ions from aqueous solution by Syzygium cumini L. was studied in a batch adsorption system as a function of pH, contact time, lead ion concentration, adsorbent concentration and adsorbent size. The biosorption capacities and rates of lead ions onto S. cumini L. were evaluated. The Langmuir, Freundlich, Redlich-Peterson and Temkin adsorption models were applied to describe the isotherms and isotherm constants. Biosorption isothermal data could be well interpreted by the Langmuir model followed by Temkin model with maximum adsorption capacity of 32.47 mg/g of lead ion on S. cumini L. leaves biomass. The kinetic experimental data were properly correlated with the second-order kinetic model. 相似文献
28.
Rakesh Sarin Ajay K. Arora Rajeev Ranjan Anurag A. Gupta Ravinder K. Malhotra 《Lubrication Science》2007,19(2):151-157
Bio‐diesel has been accepted as a renewable liquid biofuel worldwide. In order to ensure customers' acceptance, standardisation and quality assurance are the key factors to the market introduction of bio‐diesel as a transport fuel. Lubricity of bio‐diesel is an important issue and it is well reported that 1–2% bio‐diesel is sufficient to maintain the lubricity of diesel even of very poor lubricity. However, a wide variation in lubricity performance of bio‐diesel from different vegetable oils and sources has been noticed. In addition, on critical examination, it was noticed that the variation in the lubricating performance of bio‐diesel could be better linked to its residual acidity than to variation in fatty acid composition. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
29.
V.K. Jain Rakesh G. Mote 《The International Journal of Advanced Manufacturing Technology》2005,26(1-2):56-67
Electrodischarge diamond grinding (EDDG) is a hybrid machining process comprising conventional grinding and electrodischarge machining (EDM) as its constituent processes. It has the potential of shaping advanced engineering materials. Temperature of the workpiece and material removal rate are chosen as responses in full factorial (33) design with current, pulse-on time, and wheel speed as process parameters. Specific energy is a vital consideration for any machining process. EDM is known for its inefficiency. Experiments were conducted with a specially fabricated bronze disk as tool electrode to evaluate specific energy in EDM, and the results were compared with that of EDDG. It has been found that specific energy required in EDDG is less than that in EDM with a rotating disk electrode. 相似文献
30.
Susan M. O’Donnell Rakesh K. Gelda Steven W. Effler Donald C. Pierson 《Canadian Metallurgical Quarterly》2011,137(8):678-688
Effective simulation of the fate and transport of runoff event inflows is an important goal of many water quality modeling initiatives. The set-up and testing of a two-dimensional hydrodynamic transport model is documented for a water supply reservoir, Schoharie Reservoir, New York, that uses specific conductance (SC) as a conservative tracer and focuses on fate and transport of runoff event inputs, particularly the plunging of density currents in summer and fall. Model testing is supported by temporally detailed measurements of meteorological, operational, and tributary (temperature and SC) model drivers, and temporally and spatially replete in-reservoir patterns of SC following multiple runoff events, obtained with a combination of robotic monitoring platforms and gridding with rapid profiling instrumentation. Specific conductance is demonstrated to be an ideal tracer because of the distinct tributary signals and subsequent in-reservoir signatures imparted from runoff events and its close coupling to turbidity patterns that are primary water quality concerns for managers. The model is demonstrated to perform well in simulating in-reservoir signatures of SC following multiple runoff events over the spring to fall interval of 2003, including vertical, longitudinal, and temporal patterns, and features of the thermal stratification regime for the same interval. The validated model is applied in a probabilistic manner on the basis of a 61-year record (239 runoff events) of model drivers to provide a robust representation of the transport of runoff event inputs relative to the location of the water supply intake. This application demonstrates the entry of runoff event inflows as plunging density currents in summer and fall is a recurring phenomenon for this reservoir. 相似文献