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Friction 2021年第1期9卷 41-60页

作者： deepak K.PRAJAPATI Mayank TIWARI Department of Mechanical Engineering Indian Institute of TechnologyPatna 801103India

Dry wear experiments provide an insight detail on how severely contacting surfaces change under unlubricated sliding condition. The theory of dry sliding wear is used for understanding mixed-lubrication regime in which asperity interactions play a significant role in controlling of the friction coefficient(f). The purpose of this work is to study the tribological behavior of AISI 304 steel in contact with AISI 52100 steel during wear. Both materials are used in rolling element bearings commanly. Experiments are carried out using a pin-on-disc tribometer under dry friction condition. The areal(three dimensional, 3D) topography parameters are measured using a 3D white light interferometer(WLI) with a 10× objective. After wear tests, wear mechanisms are analyzed utilizing scanning electron microscope(SEM). Factorial design with custom response surface design(C-RSD) is used to study the mutual effect of load and speed on response variables such as f and topography parameters. It is observed that the root mean square roughness(S_(q)) decreases with an increase in sliding time. Within the range of sliding time, S_(q) decreases with an increase in the normal load. Within the range of sliding speed and normal load, it is found that S_(q), mean summit curvature(S_(sc)), and root mean square slope(S_(dq)) are positively correlated with f. Whereas, negative correlation is found between f and correlation length(Sal), mean summit radius(R), and core roughness depth(S_(k)).

关键词： friction coefficient(f) areal topography parameters factorial design non-contact optical profiler scanning electron microscope(SEM)

Performance evaluation of cement-stabilized pond ash-rice husk ashclay mixture as a highway construction material

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Journal of Rock Mechanics and Geotechnical Engineering 2017年第1期9卷 159-169页

作者： deepak Gupta Arvind Kumar Department of Civil Engineering National Institute of Technology (NIT) Jalandhar India

This paper reports the results of an investigation carried out on clay soil stabilized with pond ash(PA),rice husk ash(RHA) and cement. Modified Proctor compaction tests were performed in order to investigate the compaction behavior of clay, and California bearing ratio(CBR) tests were performed to determine the strength characteristics of clay. For evaluation purpose, the specimens containing different amounts of admixtures were prepared. Clay was replaced with PA and RHA at a dosage of 30%e45% and5%e20%, respectively. The influence of stabilizer types and dosages on mechanical properties of clay was evaluated. In order to study the surface morphology and crystallization characteristics of the soil samples, scanning electron microscopy(SEM) and X-ray diffraction(XRD) analyses were carried out,respectively. The results obtained indicated a decrease in the maximum dry density(MDD) and a simultaneous increase in the optimum moisture content(OMC) with the addition of PA and *** linear regression analysis(MLRA) showed that the predicted values of CBR tests are in good agreement with the experimental values. Developed stabilized soil mixtures showed satisfactory strength and can be used for construction of embankments and stabilization of sub-grade soil. The use of locally available soils, PA, RHA, and cement in the production of stabilized soils for such applications can provide sustainability for the local construction industry.

关键词： California bearing ratio(CBR) Pond ash(PA) Rice husk ash(RHA) Optimum moisture content(OMC) Maximum dry density(MDD)

Ce-Co-doped BiFeO_3 multiferroic for optoelectronic and photovoltaic applications

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Chinese Physics B 2017年第11期26卷 383-388页

作者： Jyoti Sharma deepak Basandrai A K Srivastava Department of Physics Lovely Professional University

The Ce-Co-doped BiFeO3 multiferroic, Bi（1-x）Ce）xFe（1-x）CoxO3（x = 0.00, 0.01, 0.03, and 0.05）, has been prepared by a sol-gel auto-combustion method and analyzed through Raman spectroscopy, photoluminescence, and UV-visible spectroscopy. We have observed an anomalous intensity of the second-order Raman mode at - 1260 cm^-1 in pure BFO and suppressed intensity in doped samples, which indicates the presence of spin two-phonon coupling in these *** photoluminescence spectra show reduction in the intensity of emission with the increasing dopant concentration, which indicates the high charge separation efficiency. A sharp absorption with three charge transfer（C-T） and two d-d transitions are shown by UV-visible spectra in the visible region. The band gap of BiFeO3（BFO） is decreasing with increasing dopant concentrations and the materials are suitable for photovoltaic applications.

关键词： Raman and UV-visible spectroscopy photoluminescence and photo-voltaic applications

Static and Dynamic Analyses of Spliced Column

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Sound & Vibration 2021年第3期55卷 253-262页

作者： deepak Kumar Singh Research Scholar Civil Engineering DepartmentMNNIT AllahabadPrayagraj211004India

The analysis of spliced column has been carried out to detect optimum location of providing splices in the *** the present work,static and dynamic(free vibration)analyses of spliced column have been done by randomising the location of splicing.A symmetrical four storey steel framed building has been modelled,analysed and designed for loads(dead,live and earthquake loads)recommended by Indian Codal provisions using *** critical column at each floor level is identified based on axial force(AF),bending moment(BM)and shear force(SF).The total 16 models of spliced columns have been designed and then modelled in a 3D CAD Design tool(SOLIDWORKS)and then imported in the finite element tool(ANSYSWorkbench 14.0)for detailed *** variation of stress,strain and deflection of the spliced column are shown in the form of ***,the modal analysis is performed to determine the natural *** results of static and dynamic analyses are compared for each modelled spliced column to obtain the optimum location for providing splices in the *** dynamic analysis of spliced column is of utmost importance in the region where dynamic loadings like earthquake,cyclones *** more frequent,and mere static analysis does not account for the safety of the *** study will help the engineers to select directly the optimum size and location of the splices in the column of a steel framed building.

关键词： Column splice finite element method natural frequency modal analysis static analysis steel framed building

On selection and scaling of ground motions for analysis of seismically isolated structures

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Earthquake Engineering and Engineering Vibration 2016年第4期15卷 633-648页

作者： deepak R. Pant Manika Maharjan Department of Civil Engineering University of Toronto Toronto ON M5S 1A4 Canada Atkins Limited The Wells Church Street Epsom KT17 4PE United Kingdom

A broader consensus on the number of ground motions to be used and the method of scaling to be adopted for nonlinear response history analysis （RHA） of structures is yet to be reached. Therefore, in this study, the effects of selection and scaling of ground motions on the response of seismically isolated structures, which are routinely designed using nonlinear RHA, are investigated. For this purpose, isolation systems with a range of properties subjected to bidirectional excitation are considered. Benchmark response of the isolation systems is established using large sets of unscaled ground motions systematically categorized into pulse-like, non-pulse-like, and mixed set of motions. Different subsets of seven to 14 ground motions are selected from these large sets using （a） random selection and （b） selection based on the best match of the shape of the response spectrum of ground motions to the target spectrum. Consequences of weighted scaling （also commonly referred to as amplitude scaling or linear scaling） as well as spectral matching are investigated. The ground motion selection and scaling procedures are evaluated from the viewpoint of their accuracy, efficiency, and consistency in predicting the benchmark response. It is confirmed that seven time histories are sufficient for a reliable prediction of isolation system displacement demands, for all ground motion subsets, selection and scaling procedures, and isolation systems considered. If ground motions are selected based on their best match to the shape of the target response spectrum （which should be preferred over randomly selected motions）, weighted scaling should be used if pulse-like motions are considered, either of weighted scaling or spectral matching can be used if non-pulse-like motions are considered, and an average of responses from weighted-scaled and spectrum-matched ground motions should be used for a mixed set of motions. On the other hand, the importance of randomly selected motions in represen

关键词： bidirectional excitation seismic isolation selection and scaling spectral matching weighted scaling

Ayurvedic concept of Shatkriyakala:a traditional knowledge of cancer pathogenesis and therapy

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Journal of Integrative Medicine 2017年第2期15卷 88-94页

作者： Ashutosh Chauhan deepak Kumar Semwal Satyendra Prasad mishra Ruchi Badoni Semwal Department of Biotechnology Faculty of Biomedical Sciences Uttarakhand Ayurved University Harrawala Dehradun 248001 India Department of Phytochemistry Faculty of Biomedical Sciences Uttarakhand Ayurved University Harrawala Dehradun 248001 India Uttarakhand Ayurved University Harrawala Dehradun 248001 India Department of Pharmaceutical Sciences Tshwane University of Technology Pretoria 0001 South Africa

The term Kriyakala refers to the recognition of the stage of a disease＇s progress, which helps to determine appropriate measure to correct the imbalance in Doshas （biological factors）. It is a compound expression, comprised of Kriya and Kala, where Kriya means the choice to treatment （medicine, food and daily-routine） used to improve the disturbance in Doshas, and Kala refers to the stage of progress of a disease. Sushruta, an ancient Indian surgeon, has described the concept of Kriyakala in Vamaprashnadhyaya, an ancient Vedic Sanskrit text, which seeks to explain the incidence of Vamas in terms of Doshic disturbances. Vama, in modern parlance, may be described as an inflammatory process that may lead ulceration and chronic inflammation, promoting all stages of carcinogenesis. Abnormal interactions between Prakriti （genotype） and environmental factors vitiate the Doshas and impair immunity, which can lead to aberrant cell growth and cancer. Moreover, the interaction between vitiated Doshas and weak Dhatus （body tissues） manifests as cancers of a specific organ. Shatkriyakala （six stages of progress of a disease）, on the other hand, provides a framework to assess the cancer and its pathogenesis in different stages. According to Ayurvedic concepts, all cancer therapies treat the affected tissues indirectly by eliminating vitiated Doshas, rejuvenating Dhatus and restoring immunity in cancer patients. The present review describes the six stages of Shatkriyakala in detail, with an emphasis on research areas to validate the concept of Shatkriyakala. This traditional knowledge can be utilized with modern technologies to detect predisposition for cancer or diagnose cancer in its early stages.

关键词： medicine, Ayurvedic Shatkriyakala tumors, malignant

Enhanced photocatalytic activity of electrochemically synthesized aluminum oxide nanoparticles

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International Journal of Minerals,Metallurgy and Materials 2016年第3期23卷 358-371页

作者： deepak Pathania Rishu Katwal Harpreet Kaur School of Chemistry Shoolini UniversitySolan-173212(H.P.)India Department of Chemistry Punjabi UniversityPatiala-147002(Punjab)India

In this study, aluminum oxide （Al2O3） nanoparticles （NPs） were synthesized via an electrochemical method. The effects of reac- tion parameters such as supporting electrolytes, solvent, current and electrolysis time on the shape and size of the resulting NPs were investi- gated. The Al2O3 NPs were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, transmission electron microscopy, thermogravimetric analysis/differential thermal analysis, energy-dispersive X-ray analysis, and ultraviolet-visible spectroscopy. Moreover, the Al2O3 NPs were explored for photocatalytic degradation of malachite green （MG） dye under sunlight irradiation via two processes： ad- sorption followed by photocatalysis; coupled adsorption and photocatalysis. The coupled process exhibited a higher photodegradation effi- ciency （45%） compared to adsorption followed by photocatalysis （32%）. The obtained kinetic data was well fitted using a pseudo-first-order model for MG degradation.

关键词： aluminum oxide nanoparticles electrochemical preparation photocatalysis

NMR relaxation and diffusion studies to probe the motional dynamics of risperidone within PLGA microsphere

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Magnetic Resonance Letters 2023年第2期3卷 197-205,I0005页

作者： deepak Kumar Samanwita Pal Department of Chemistry Indian Institute of Technology JodhpurRajasthan342037.India Central Ayurveda Research Institute Kolkata CCRASBidhannagarKolkata700091India

The present study aims to investigate the motional dynamics of risperidone within polylactic co-glycolic acid(PLGA)microsphere by employing solution state'H and 19F nuclear magnetic resonance(NMR)***,a second-generation fluorinated antipsychotic drug used for the treatment of schizophrenia is commercially marketed as PLGA microsphere formulation resulting in prolonged release of the drug in *** the current trend in the pharmaceutical market is to develop drug formulation with long-acting release(LAR)products,complete physicochemical characterization of such formulations are *** the effects of microsphere encapsulation on the motional properties and diffusion behavior of the drugs are not discussed adequately in any of the earlier *** therefore,have employed NMR relaxation and diffusion measurements to decipher the interaction of PLGA cavity water with risperidone.A detailed analysis of NMR relaxation rates confirmed the event of encapsulation and the presence of local motion in the non-fluorinated end of ***,the relaxation data indicated a significant alteration in 19F chemical shift anisotropy(CSA)and CSA/dipole-dipole(DD)cross-correlated relaxation mechanism and decreased effect of solvent relaxation pointing out reduced water concentration within the microsphere cavity.'H and 19F diffusion coefficients of risperidone led to the information about hydrodynamic radius of risperidone in free and encapsulated *** of hydrodynamic radius supported the presence of limited water in PLGA cavity allowing higher translational mobility of risperidone after the encapsulation.

关键词： Polylactic co-glycolic acid(PLGA)microsphere Motional dynamics 1H and 19F NMR Diffusion Hydrodynamic radius Cross-correlated relaxation

Sustainability Assessment and Ranking of Run of the River(RoR) Hydropower Projects Using Analytical Hierarchy Process(AHP):A Study from Western Himalayan Region of India

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Journal of Mountain Science 2015年第5期12卷 1315-1333页

作者： deepak KUMAR Surjit Singh KATOCH Centre for Energy and Environmental Engineering National Institute of Technology

In the present scenario,tapping the unutilised hydropower potential is one of the highest priorities in developing countries of the *** emphasis is being imparted to run of the river(RoR)mode of power ***,the governments are now facing the dilemma whether to promote small hydropower projects(SHPs) or encourage large hydropower projects(LHPs).RoR large hydropower projects result into large scale cutting of mountains for constructing tunnels and access roads,generation of huge quantity of muck and large scale impact on flora and fauna due to diversion of rivers/*** the other hand,though SHPs are claimed to be greener and more sustainable by a section of researchers and energy planners but,they will be required to be set up in large number to generate equivalent amount of *** aim of this study is to rank the most sustainable installed capacity range of RoR hydropower *** achieve this aim,the study proposes the use of quite popular multi-criteria decision making(MCDM)method of Operation Research named Analytical Hierarchy Process.A case study has been presented from Himachal Pradesh,a hydro rich state located in the western Himalayan *** per sustainability assessment carried out in this study,hydropower projects in the capacity range 1 to 5 MW have been ranked to be the most sustainable.

关键词： Sustainability Run of the river Hydropower project Analytical Hierarchy Process Himalaya

Second harmonic generation of high power Cosh-Gaussian beam in cold collisionless plasma

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Communications in Theoretical Physics 2022年第10期74卷 127-135页

作者： Keshav Walia Kulkaran Singh deepak Tripathi Department of Physics DAV UniversityJalandharIndia Department of Physics AIASAmity UniversityNoidaIndia

The purpose of this study is to explore the second harmonic generation(SHG)of a high power Cosh-Gaussian beam in cold collisionless *** ponderomotive force causes carrier redistribution from high field to low field region in presence of a Cosh-Gaussian beam thereby producing density gradients in the transverse *** density gradients so produced the results in electron plasma wave(EPW)generation at the frequency of the input *** EPW interacts with the input beam resulting in the production of 2nd *** and paraxial approximations are employed for obtaining the 2nd order differential equation describing the behavior of the beam’s spot size against normalized *** impact of well-established laser-plasma parameters on the behavior of the beam’s spot size and SHG yield are also *** focusing behavior of the beam and SHG yield is enhanced with an increase in the density of plasma,the radius of the beam and the decentred parameter,and with a decrease in the intensity of the *** results of the current problem are really helpful for complete information of laser-plasma interaction physics.

关键词： second harmonic generation cold collisionless plasma ponderomotive force electron plasma wave Cosh-Gaussian beam