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Antioxidant Capacity and Phenolic Content of Some Nepalese Medicinal Plants

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American Journal of Plant Sciences 2013年第8期4卷 1660-1665页

作者： Bijaya Laxmi Maharjan bikash baral Biotechnology Laboratory Nepal Academy of Science and Technology (NAST) Kathmandu Nepal. Natural Products Research Laboratory Nepal Academy of Science and Technology (NAST) Kathmandu Nepal

Antioxidant capacities and phenolic contents of medicinal plants namely Usnea longifolia, Cetraria nepalensis, Parmelia minarum, Everniastrum nepalense, Rhododendron anthopogon and Fritillaria delavayi were analyzed via Folin-Ciocaltau assay, Ferric reducing activity power assay and 2,2-Diphenyl-1-picrylhydrazyl assay. All the tested plants depicted the antioxidant activity with variation in extent of activity among the plants. The FRAP (F-value: 387.4), DPPH (F-value: 89.684) and TPC (F-value: 559.163) values between the extracts showed the highly significant differences (P < 0.01). This study indicated the strong antioxidant potential of R. anthopogon among the plants tested.

关键词： DPPH FRAP Fritillaria Lichens Phytochemicals Rhododendron TPC

Effects of slip, viscous dissipation and Joule heating on the MHD flow and heat transfer of a second grade fluid past a radially stretching sheet

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Applied Mathematics and Mechanics(English Edition) 2010年第2期31卷 159-173页

作者： bikash SAHOO Department of Mathematics National Institute of Technology

The flow and heat transfer of an electrically conducting non-Newtonian second grade fluid due to a radially stretching surface with partial slip is considered. The partial slip is controlled by a dimensionless slip factor, which varies between zero （total adhesion） and infinity （full slip）. Suitable similarity transformations are used to reduce the resulting highly nonlinear partial differential equations into ordinary differential equations. The issue of paucity of boundary conditions is addressed and an effective numerical scheme is adopted to solve the obtained differential equations even without augmenting any extra boundary conditions. The important findings in this communication are the combined effects of the partial slip, magnetic interaction parameter and the second grade fluid parameter on the velocity and temperature fields. It is interesting to find that the slip increases the momentum and thermal boundary layer thickness. As the slip increases in magnitude, permitting more fluid to slip past the sheet, the skin friction coefficient decreases in magnitude and approaches zero for higher values of the slip parameter, i.e., the fluid behaves as though it were inviscid. The presence of a magnetic field has also substantial effects on velocity and temperature fields.

关键词： second grade fluid stretching sheet partial slip heat transfer finitedifference method Broyden's method

Spectral Characteristic Based on Fabry–Pérot Laser Diode with Two-Stage Optical Feedback

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Chinese Physics Letters 2013年第1期30卷 87-90页

作者： WU Jian-Wei bikash NAKARMI Chongqing Key Laboratory of Optoelectronic Functional Material Chongqing Normal UniversityChongqing 400047 State Key Laboratory of Millimeter Waves Nanjing 210096 College of Science Hohai UniversityNanjing 210098 Department of Information and Communication engineering Korea Advanced Institute of Science and TechnologyDaejeon 305-714R.Korea

An optical device,consisting of a multi-mode Fabry–Pérot laser diode(MMFP-LD)with two-stage optical feedback,is proposed and experimentally *** results show that the single-mode output with side-mode suppression ratio(SMSR)of~21.7 dB is attained by using the first-stage *** using the second-stage feedback,the SMSR of single-mode operation could be increased to~28.5 dB while injection feedback power of-29 dBm is introduced into the laser *** the case of up to-29 dBm feedback power,the outcome SMSR is rapidly decayed to a very low level so that an obvious multi-mode operation in the output spectrum could be achieved at the feedback power level of-15.5 ***,a transition between single-and multi-mode operations could be flexibly controlled by adjusting the injected power in the second-stage feedback ***,in the case of injection locking,the outcome SMSR and output power at the locked wavelength are as high as~50 dB and~5.8 dBm,respectively.

关键词： SMS mode injection

A power and wavelength detuning-dependent hysteresis loop in a single mode Fabry-Prot laser diode

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Chinese Physics B 2013年第8期22卷 434-438页

作者：吴建伟 bikash Nakarmi Chongqing Key Laboratory of Optoelectronic Functional Material Chongqing Normal University State Key Laboratory of Millimeter Waves Department of Electrical Engineering Korea Advanced Institute of Science and Technology Department of Information and Communication Engineering Korea Advanced Institute of Science and Technology

In this paper, we observe experimentally the optical bistability induced by the side-mode injection power and wave- length detuning in a single mode Fabry-P6rot laser diode （SMFP-LD）. Results show that the bistability characteristics of the dominant and injected modes are strongly dependent on the injected input optical power and wavelength detuning in an SMFP-LD. We observe three types of hysteresis loops： counterclockwise, clockwise, and butterfly hysteresis with various loop widths. In the case of a bistability loop caused by injection power, the transition from counterclockwise to clockwise in the hysteresis direction with the wavelength detuning from 0.028 nm to 0.112 nm is observed in a way of butterfly hys- teresis for the dominant mode by increasing the wavelength detuning. The width of hysteresis loop, induced by wavelength detuning is also changed while the injection power is enhanced from -7 dBm to -5 dBm.

关键词： single mode Fabry-P6rot laser diode injection locking behavior optical bistability

Transition metal-based single-atom catalysts(TM-SACs);rising materials for electrochemical CO_(2) reduction

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Journal of Energy Chemistry 2022年第7期31卷 444-471,I0012页

作者： Bishnupad Mohanty Suddhasatwa Basu bikash Kumar Jena Materials Chemistry Department CSIR-Institute of Minerals and Materials TechnologyBhubaneswar 751013India Academy of Scientific&Innovative Research(AcSIR) Ghaziabad 201002India

The continuous increase of global atmospheric CO_(2) concentrations brutally damages our environment. A series of methods have been developed to convert CO_(2) to valuable fuels and value-added chemicals to maintain the equilibrium of carbon cycles. The electrochemical CO_(2) reduction reaction(CO_(2)RR) is one of the promising methods to produce fuels and chemicals, and it could offer sustainable paths to decrease carbon intensity and support renewable energy. Thus, significant research efforts and highly efficient catalysts are essential for converting CO_(2) into other valuable chemicals and fuels. Transition metal-based single atoms catalysts(TM-SACs) have recently received much attention and offer outstanding electrochemical applications with high activity and selectivity opportunities. By taking advantage of both heterogeneous and homogeneous catalysts, TM-SACs are the new rising star for electrochemical conversion of CO_(2) to the value-added product with high selectivity. In recent years, enormous research effort has been made to synthesize different TM-SACs with different M–Nxsites and study the electrochemical conversion of CO_(2) to CO. This review has discussed the development and characterization of different TMSACs with various catalytic sites, fundamental understanding of the electrochemical process in CO_(2) RR,intrinsic catalytic activity, and molecular strategics of SACs responsible for CO_(2)RR. Furthermore, we extensively review previous studies on 1 st-row transition metals TM-SACs(Ni, Co, Fe, Cu, Zn, Sn) and dual-atom catalysts(DACs) utilized for electrochemical CO_(2) conversions and highlight the opportunities and challenges.

关键词： CO_(2)RR Single-atom catalyst SACs Dual-atom catalyst DACs Transition metals Support catalysts

Existence and uniqueness theorem for flow and heat transfer of a non-Newtonian fluid over a stretching sheet

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第5期8卷 766-771页

作者： SAHOO bikash SHARMA H.G. Department of Mathematics Indian Institute of Technology RoorkeeUttaranchal 247667India

Analysis is carried out to study the existence, uniqueness and behavior of exact solutions of the fourth order nonlinear coupled ordinary differential equations arising in the flow and heat transfer of a viscoelastic, electrically conducting fluid past a continuously stretching sheet. The ranges of the parametric values are obtained for which the system has a unique pair of solutions, a double pair of solutions and infinitely many solutions.

关键词： Viscoelastic fluid Stretching sheet MHD flow Heat transfer Nonlinear systems Existence Uniqueness

Effects of operating pressure on the key parameters of coal direct chemical looping combustion

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International Journal of Coal Science & Technology 2016年第1期3卷 20-27页

作者： Rahul Wadhwani bikash Mohanty Department of Chemical Engineering Indian Institute ofTechnology Roorkee Roorkee India

Techno-economic development of chemical looping combustion （CLC） process has been one of the most pursued research areas of the present decade due to its ability to reduce carbon foot print during utilization of coal to generate energy. Based on a 2D computational fluid dynamics model, the present work provides a computational approach to study the effect of operating pressure--a key parameter in designing of CLC reactors, on optimum operating conditions. The effects of operating pressure have been examined in terms of reactors temperature, percentage of fuel conversion and purity of carbon dioxide in fuel reactor exhaust. The simulated results show qualitative agreement with the trends obtained by other investigators during experimental studies.

关键词： Operating pressure Chemical looping combustion Computational fluid dynamics (CFD)

A Smoothed Particle Hydrodynamics method for vertical axis turbine design and assessment

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Journal of Hydrodynamics 2024年第5期36卷 991-1007页

作者： Nicolas Hanousek bikash Ranabhat Aaron English Reza Ahmadian Hydro-environmental Research Centre School of EngineeringCardiff UniversityCardiffUK Department of Engineering and Architecture University of ParmaParmaItaly

With the global demand for more electricity,and for that electricity to be produced using low-carbon generation,a turbine was designed to extract energy from underutilised *** mechanism by which the turbine operates makes it highly demanding to represent using mesh-based numerical schemes,resulting in a need to investigate alternative *** Smoothed Particle Hydrodynamics(SPH)software,DualSPHysics,utilising the Chrono solid body solver,was used to represent the turbine as a free body in a 2-D environment allowing for evaluation of the free-spin velocity to be *** aim of this being to ascertain the applicability of SPH to the modelling of vertical axis turbines with multiple moving parts,and also develop an understanding of the design *** model was found to compare favourably with lab results,showing that a vertical axis turbine may be represented in this *** resilience of the device,a design driver and previously untested mode,was assessed by considering post-damage *** this,future flume study and parallel numerical modelling can guide this or other vertical axis turbines towards improved performance.

关键词： Smoothed Particle Hydrodynamics(SPH) DualSPHysics vertical-axis turbine hydrokinetic energy renewable energy

MHD flow and heat transfer from continuous surface in uniform free stream of non-Newtonian fluid

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Applied Mathematics and Mechanics(English Edition) 2007年第11期28卷 1467-1477页

作者： bikash Sahoo H.G Sharma Department of Mathematics Indian Institute of Technology RoorkeeRoorkeeUttarakhand-247667India

An analysis is carried out to study the steady flow and heat transfer characteristics from a continuous flat surface moving in a parallel free stream of an electrically conducting non-Newtonian viscoelastic fluid. The flow is subjected to a transverse uniform magnetic field. The constitutive equation of the fluid is modeled by that for a second grade fluid. Numerical results are obtained for the distribution of velocity and temperature profiles. The effects of various physical parameters like viscoelastic parameter, magnetic parameter and Prandtl number on various momentum and heat transfer characteristics are discussed in detail and shown graphically.

关键词： second grade fluid free stream heat transfer magnetic field finite difference method