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Bearing capacity of foundations on rock slopes intersected by non-persistent discontinuity

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International Journal of Mining Science and Technology 2020年第5期30卷 669-674页

作者： Divya Shaunik mahendra singh Department of Civil Engineering Indian Institute of Technology RoorkeeRoorkee 247667India

Rocks encountered in foundations of heavy structures are invariably intersected by discontinuities(joints).In the past,several studies have been performed by researchers to incorporate the effect of fully persistent joints in the assessment of the load-carrying capacity of ***,in the field,the joints are non-persistent,and an assumption of full persistency will underestimate the ***,Shaunik&singh have studied the influence of non-persistency,number of joint segments and discontinuity orientation on the strength behaviour of rock specimens(Shaunik and singh,2019).Bell’s approach can be used to obtain the bearing capacity of shallow foundations placed in jointed *** the present study,results of the experimental work(Shaunik and singh,2019)conducted by Shaunik&singh have been used to suggest expressions by extending Bell’s approach for computing bearing capacity of the foundation placed near the crown of a rock *** to use design charts are also presented for field ***,a real-life problem from Indian Garhwal Himalayas is considered,and the approach suggested in this study is utilised to obtain the bearing capacity of a bridge foundation as a function of uniaxial compressive strength(UCS)of intact rock,joint friction,spacing and orientation of joint,nonpersistency and number of joint segments.

关键词： Uniaxial compressive strength(UCS) Joint segment Discontinuity Non-persistency Bell’s approach

Strength behaviour of a model rock intersected by non-persistent joint

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Journal of Rock Mechanics and Geotechnical Engineering 2019年第6期11卷 1243-1255页

作者： Divya Shaunik mahendra singh Department of Civil Engineering Indian Institute of Technology Roorkee

Several constructions in the field of civil engineering quite often need to deal with *** behaviour of rock intersected by a discontinuity or a set of discontinuities has been a topic of keen interest for engineering *** popular attributes of discontinuities that have been given due importance are their frequency,orientation and surface ***-persistency,however,has been given little *** article presents an experimental study wherein focus has been made on the effect of non-persistency of the joint on the uniaxial compressive strength(UCS)of a model rock for various geometries such as orientation,discontinuity length ratio and number of joint *** applicability of single plane of weakness theory(SPWT)to assess the strength of jointed specimens has also been *** has been noticed that SPWT captures the strength behaviour only for a narrow range of discontinuity *** an improvement,an approach is suggested by extending concepts of degree of persistence and joint factor to have a better understanding towards strength behaviour of rocks intersected by non-persistent joints.

关键词： Uniaxial compressive strength (UCS) Joint segment Non-persistency Joint factor

STOCHASTIC SYNCHRONIZATION OF CIRCADIAN RHYTHMS

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Journal of Systems Science & Complexity 2010年第5期23卷 978-988页

作者： RajKumar Brojen singh vikram singh Ram RAMASWAMY Centre for Interdisciplinary Research in Basic Sciences Jamia Milia Islamia New Delhi 110025 India Center for Computational Biology and Bioinformatics School of Information Technology Jawaharlal Nehru University New Delhi 110067 India Center for Computational Biology and Bioinformatics School of Information Technology and School of Physical Sciences Jawaharlal Nehru University New Delhi 110067 India

Models of circadian genetic oscillators involving interlinked feedback processes in molecular level genetic networks in Drosophila melanogaster and Neurospora crassa are studied, and mechanisms whereby synchronization can arise in an assembly of cells are examined. The individual subcellular circadian oscillatory processes are stochastic in nature due to the small numbers of molecules that are involved, and are subject to large fluctuations. The authors investigate and present the simulations of the stochastic dynamics of ensembles of clock-regulating proteins in different nuclei that communicate via ancillary small molecules, environmental parameters, additive cellular noise, or through diffusive processes. The results show that the emergence of collective oscillations is a macroscopic observable which has its origins in the microscopic coupling between distinct cellular oscillators.

关键词： Coupling stochastic dynamics synchrony.

Seismic analysis of structures with a fractional derivative model of viscoelastic dampers

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Earthquake Engineering and Engineering Vibration 2002年第2期1卷 251-260页

作者： Tsu-sheng Chang mahendra P.singh Department of Engineering Science and Mechanics.Virginia Polytechnic Institute and State Universigy.Blacksburg Virginia24061.USA

Viscoelastic dampers are now among some of the preferred energy dissipation devices used for passive seismic response *** evaluate the performance of structures installed with viscoelastic dampers,different analytical models have been used to characterize their dynamic force deformation *** fractional derivative models have received favorable attention as they can capture the frequency dependence of the material stiffness and damping properties observed in the tests very ***,accurate analytical procedures are needed to calculate the response of structures with such damper *** paper presents a modal analysis approach,similar to that used for the analysis of linear systems,for solving the equations of inotion with fractional derivative terms for arbitrary forcing functions such as those caused by earthquake induced ground *** uncoupled modal equations still have fractional derivatives,but can be solved by numerical or analytical *** numerical and analytical procedures are *** procedures are then used to calculate the dynamic response of a multi-degree of fleedom shear beam structure excited by ground motions. Numerical results demonstrating the response reducing effect of viscoelastic dampers are also presented.

关键词： viscoelastic damper fractioal derivative seismic response

Cervical cancer:a tale from HPV infection to PARP inhibitors

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Genes & Diseases 2023年第4期10卷 1445-1456页

作者： Minakshi Mann vikram Pratap singh Lalit Kumar Department of Medical Oncology Dr.B.R.A.Institute Rotary Cancer HospitalAll India Institute of Medical SciencesNew Delhi 110029India Department of Oncoanaesthesia and Palliative Medicine Dr.B.R.A.Institute Rotary Cancer HospitalAll India Institute of Medical SciencesNew Delhi 110029India Epigenetics Section Mouse Cancer Genetics ProgramCenter for Cancer ResearchNational Cancer InstituteFrederickMD 21702USA

Globally,cervical cancer(CxCa)ranks 4th common cancer among females and led to 569,847 incidences and 311,365 deaths in 2018.80%of CxCa cases occur due to persistent infection with a high-risk subtype of human papillomavirus(HPV-16 and 18).Smoking,high par-ity,and co-infection with type 2 herpes simplex or HIV are other known risk factors for *** histological subtypes are squamous(70%)and adenocarcinoma(25%).Presently,concur-rent radiation plus cisplatin(CDDP)-based chemotherapy is the standard treatment for CxCa ***,CDDP resistance and toxic side effects limit its efficacy,leading to a poorer response rate and an expected overall survival ranging from 10 to 17.5 *** drug uptake,increased DNA damage repair,increased CDDP inactivation,and overexpressed Bcl-2 or caspase inhibition,are primarily accountable mechanisms for CDDP resistance and improving CDDP’s efficacy remains the major ***(ADP-ribosyl)polymerase-1,an effective mediator of nucleotide excision repair pathway,is involved in DNA repair as well as maintaining genomic stability and is significantly expressed in malignant lymphomas,hepa-tocellular-,cervical-and colorectal carcinoma,which has been approved effective in mainte-nance therapy and may serve as an effective target to enhance CDDP sensitivity in ***,we summarize the etiology and epidemiology of and treatment for CxCa,the mechanism responsible for chemotherapy resistance,PARP inhibitor as a possible therapy for CxCa,and other possible chemotherapeutic options for CxCa treatment.

关键词： Cervical cancer Chemotherapy Cisplatin Disease etiology and histology PARP inhibitors Resistance

Rifabutin reduces systemic exposure of an antimalarial drug 97/78 upon co-administration in rats:an in-vivo & in-vitro analysis

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Asian Pacific Journal of Tropical Medicine 2015年第8期8卷 620-625页

作者： Yeshwant singh mahendra Kumar Hidau Shio Kumar singh Pharmacokinetics & Metabolism Division CSIR-Central Drug Research Institute Academy of Scientific and Innovative Research

Objective: To determine the potential drug-drug interactions between anti-malarial candidate 97/78 and anti-tubercular drug rifabutin in-vivo in rats followed by in-vitro investigation of the underlying mechanisms of drug interaction. Methods: Single oral dose study was conducted in male and female rats at 40 mg/kg and 70 mg/kg for 97/78 and rifabutin respectively. Results: It was reported that rifabutin co-administration altered pharmacokinetics of 97/63(active metabolite of 97/78). A significant decrease was reported in the systemic exposure of 97/63 by a factor of 3-4. The AUC0-last values were(4.03 ± 0.60) and(5.44 ± 1.15) μg·h·m L-1 upon 97/78 administration alone, while the values were decreased to(1.13 ± 0.10) and(1.23 ± 1.13) μg·h·m L-1 upon rifabutin co-administration in male and female rats respectively. Statistically significant differences were also reported in Cmax and Tmax values upon rifabutin co-administration. In-vitro drug metabolism study in rat liver microsomes has shown that the metabolism of 97/63 was increased by 10%-12% upon rifabutin co-incubation. The extent of plasma protein binding of 97/63 was found to be decreased from 54%-55% to 6%-8% upon rifabutin addition. Conclusions: It was concluded that rifabutin co-administration altered PK parameters of 97/63 in SD rats. However, no intersex influences were reported in the interaction pattern. The results obtained in the in-vivo study were well correlated with the invitro findings and can further be applied to explore other aspects of potential drug interactions between these two drugs.

关键词： Accumulation Relative bioavailability Sex effect Pharmacokinetics

An overview of β-carotene production:Current status and future prospects

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Food Bioscience 2022年第3期47卷 111-120页

作者： Rahul vikram singh Krishika Sambyal Academy of Scientific and Innovative Research (AcSIR) Ghaziabad201002India University Institute of Biotechnology Chandigarh UniversityGharuanPunjabIndia

β-carotene is being used in the food industry as an orange-red pigment for making various food products due to its valuable physical and biological *** use of naturally produced β-carotene has many health benefits rather than the majorly used synthetic production ***,the use of microbial production for β-carotene synthesis can be a promising future for the industries due to its low production cost,use of less manpower,high product yield and eco-friendly production *** present review provides an overview of various β-carotene production methods and their future scope using green industrial production.

关键词： β-Carotene Microbial production Pigment Metabolic engineering Vitamin A

Controllability of multi-term time-fractional differential systems

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Journal of Control and Decision 2020年第2期7卷 109-125页

作者： vikram singh Dwijendra N.Pandey Department of Mathematics Indian Institute of Technology RoorkeeRoorkee 247667India

In this paper,an abstract multi-term time-fractional differential system is considered and the exact controllability results are *** this theory,we tend to implement the basic tools of fractional calculus and measure of noncompactness to come up with a new set of sufficient conditions for the exact controllability by utilisation of Mönch fixed point ***,an application is given to illustrate the obtained results.

关键词： Fractional calculus exact controllability multi-term time-fractional delay differential system measure of noncompactness

Aqueous organic redox flow batteries

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Nano Research 2019年第9期12卷 1988-2001页

作者： vikram singh Soeun Kim Jungtaek Kang Hye Ryung Byon Department of Chemistry Korea Advanced Institute of Science and Technology (KAIST)291 Daehak-roYuseong-guDaejeon 34141Republic of Korea Advanced Battery Center KAIST Institute for NanoCentury291 Daehak-roYuseong-guDaejeon 34141Republic of Korea

Redox flow batteries(RFBs)are promising candidates to establish a grid-scale energy storage system for intermittent energy *** the current technology of vanadium RFBs has been widely exploited across the world,the rise in the price of vanadium and its limited volumetric energy density have necessitated the development of new kinds of redox active *** molecules can be used as new and economical redox couples in RFBs to address these *** addition,the redox organic species also provide ample advantages to increase the voltage and solubility,provide multiple numbers of electron transfer,and ensure electrochemical/chemical stability by molecular engineering through simple synthetic *** review focuses on the recent developments in aqueous organic RFBs,including the molecular design and the corresponding cycling performance as these organic redox molecules are employed as either the negolyte or *** strategies for tuning the electrochemical/chemical characteristics of organic molecules have improved their solubility,redox potential cycling stability,and crossover issue across a separating *** also put forward new strategies using nanotechnology and our perspective for the future development of this rapidly growing field.

关键词： redox flow battery redox molecules quinone 2,2,6,6-tetramethylpiperidin-1-yl)oxyl(TEMPO) viologen solubility crossover