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Reciprocating sliding tribology of brake oil treated carbon fiber reinforced ceramic matrix composites

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Transactions of Nonferrous Metals Society of China 2019年第9期29卷 1903-1913页

作者： Parshant kumar vijay kumar SRIVASTAVA Department of Mechanical Engineering Indian Institute of Technology (Banaras Hindu University)

The effect of brake oil on sliding behavior of carbon/carbon(C/C) and carbon/carbon-silicon carbide(C/C-SiC) composites was investigated with the variation of laminate orientation and surface conformity. The partial and low conformity contacts with the normal and parallel orientations of laminates were considered. The normal load was varied from 50 to 90 N in a step of 10 N. The friction and wear behavior was investigated under reciprocating sliding conditions. The results showed that friction coefficient and wear loss of composites with normal orientation of laminates were larger as compared to those of composites with parallel orientation of laminates. C/C composites with normal orientation of laminates yielded the highest value of friction coefficient. Wear loss decreased by a maximum of 78%, and friction coefficient decreased by a maximum of 49% in low conformity contacts as compared to partial conformity contacts. The presence of brake oil reduced the adhesion tendency of compacted wear debris because the formation of friction film was difficult, and thus, friction behavior was affected. The wear debris retention between the contact surfaces due to confined area motion in reciprocating sliding depicted the tribological behavior.

关键词： reciprocating sliding tribology C/C composites C/C-SiC composites friction coefficient wear resistance laminate orientation

An interval type-2 fuzzy logic controller for TCSC to improve the damping of power system oscillations

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Frontiers in Energy 2013年第3期7卷 307-316页

作者： Manoj kumar PANDA Gopinath PILLAI vijay kumarx Electronics & Computer Engineering Department Indian Institute ofTechnology Roorkee 247667 India Electrical Engineering Department Indian Institute of TechnologyRoorkee 247667 India

In this paper an interval type-2 fuzzy logic controller （IT2FLC） was proposed for thyristor controlled series capacitor （TCSC） to improve power system damping. For controller design, memberships of system variables were represented using interval type-2 fuzzy sets. The three-dimensional membership function of type-2 fuzzy sets provided additional degree of freedom that made it possible to directly model and handle uncertainties. Simulations conducted on a single machine infinite bus （SMIB） power system showed that the proposed controller was more effective than particle swarm optimization （PSO） tuned and type-1 fuzzy logic （T1FL） based damping controllers. Robust performance of the proposed controller was also validated at different operating conditions, various disturbances and parameter variation of the transmission line parameters.

关键词： power system oscillations thyristor controlled series capacitor (TCSC) type-2 fuzzy logic system interval type-2 fuzzy logic controller (IT2FLC)

Fast internal preheating of 4680 lithium-ion batteries in cold environments

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Nano Research 2024年第10期17卷 8794-8802页

作者： Chuyue Guan Harrison Szeto Olivia Wander vijay kumar Raphaele JClément Yangying Zhu Department of Mechanical Engineering University of California Santa BarbaraSanta BarbaraCA 93106USA Department of Chemistry and Biochemistry University of California Santa BarbaraSanta BarbaraCA 93106USA Department of Materials University of California Santa BarbaraSanta BarbaraCA 93106USA

Lithium-ion batteries are expected to operate within a narrow temperature window around room temperature for optimal performance and ***,in cold environments,electric vehicle battery packs must be extensively preheated prior to charge or ***,conventional preheating is accomplished externally,which is slow and thus significantly increases charging ***,internal heating has been demonstrated as a potential solution to quickly and uniformly preheat a lithium-ion pouch ***,internal heating has not been evaluated in other battery formats such as cylindrical *** this work,we present a numerical model of a 4680 battery with internal heaters for fast preheating in cold *** effects that the number of heater layers,heating duration,resting duration,environmental temperature,and boundary heat transfer coefficient have on the temperature heterogeneity of the battery were *** results show that internal heating alone reduces the temperature variation within the battery by a factor of 5 compared to external heating,and by a factor of 20 when combining internal and external *** study further proves that internal preheating of lithium-ion batteries is a promising thermal management strategy,and provides guidance on potential design considerations and heating protocols to implement internal heating.

关键词： lithium-ion battery 4680 battery thermal management internal battery preheating COMSOL Multiphysics thermal simulation battery temperature heterogeneity

Machine learning based fault detection and state of health estimation of proton exchange membrane fuel cells

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Energy and AI 2023年第2期12卷 178-186页

作者： vijay Mohan Nagulapati SShiva kumar Vimalesh Annadurai Hankwon Lim School of Energy and Chemical Engineering Ulsan National Institute of Science and Technology50 UNIST-gilEonyang-eupUlju-gunUlsan44919Republic of Korea Carbon Neutrality Demonstration and Research Center Ulsan National Institute of Science and Technology50 UNIST-gilEonyang-eupUlju-gunUlsan44919Republic of Korea Department of Mechatronics Rajalakshmi Engineering CollegeChennaiTamilnaduIndia Graduate School of Carbon Neutrality Ulsan National Institute of Science and Technology50 UNIST-gilEonyang-eupUlju-gunUlsan44919Republic of Korea

In fuel cells, chemical energy is directly converted into heat and electricity without any emissions which makes them an attractive substitute for various energy needs. Fuel cells have high energy conversion ratio and highpower densities which make them suitable for automotive applications. However, these fuel cell systems suffer with low reliability and durability as system components develop faults during operation resulting in degradation and diminished system performance. In this context, fault detection and fault mitigation strategies are being extensively developed. Diagnostic approaches like electrochemical impedance spectroscopy, cyclic voltammetry, and galvanostatic analysis offer a truthful representation of the State of Health (SOH) of the fuel cell. However, these approaches are intrusive and require pausing the operation of the fuel cell effecting its integrity. Machine learning based fault detection and SOH estimation is a non-intrusive approach where a mapping function is established between the indicators and SOH. The SOH of a fuel cell can be correlated to the patterns in sensor signals or indicators. Indicators that influence SOH are cell voltages, current density distribution, impedance spectra, acoustic emission and magnetic fields. Developing an accurate fault detection and state estimation technique through data driven machine learning approaches will allow corrective measures to avoid irreversible faults and improve the reliability and durability of fuel cells.

关键词： PEM fuel cell Data driven prognostics Fault detection Dynamic load test Gaussian process regression Support vector machine Artificial neural networks

Artificial neural network (ANNs) and mathematical modelling of hydration of green chickpea

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Information Processing in Agriculture 2021年第1期8卷 75-86页

作者： Yogesh kumar Lochan Singh vijay Singh Sharanagat Ayon Tarafdar Department of Food Engineering National Institute of Food Technology Entrepreneurship and ManagementHaryanaIndia Department of Agriculture and Environmental Sciences National Institute of Food Technology Entrepreneurship and ManagementHaryanaIndia

The present study was aimed to model the hydration characteristics of green chickpea(GC)using mathematical modelling and examine predictive ability of artificial neural network(ANN)*** of GC was performed at different temperatures 25,35,45,55 and 65℃.Different mathematical models were tested for the hydration at different *** ANN modelling,the hydration time and hydration temperature were used as input variables and moisture ratio,moisture content and hydration ratio were taken as output *** model best described the hydration behavior at 25℃;while hydration at high-temperature was better described by Page model and Ibarz et *** optimum temperature obtained for hydration was 35℃.Effective mass diffusion coefficient(D_(e))increased from 1.5510^(-11)-1.7910^(-9) m^(2)/s with the increase in the hydration *** low activation energy(39.66 kJ/moL)shows the low-temperature sensitiveness of *** temperature hydration(25℃)required higher time(>200 min)to achieve the equilibrium moisture content(EMC),however high temperature hydration(35–65℃)reduced the EMC time(150 min).ANN was used to predict the hydration behavior and K fold cross validation was performed to check the over fitting of ANN *** show that the LOGSIGMOID transfer function showed better performance when used at the hidden layer input node in conjunction to both PURELIN and *** was found suitable for moisture ratio(MR)and hydration ratio(HR)prediction,as opposed to PURELIN for moisture content(MC)*** model prediction was obtained when the number of neurons in the hidden layer for MC,MR and HR was 12,8 and 15,*** and ANN modelling results are useful to improve/predict the MC,MR and HR during hydration process of GC at different temperature and other similar process.

关键词： Green chickpea Water absorption Hydration temperature ANN modeling

One Pot Reduction of Imines Generated in-situ from Aldehydes and Amines by the NaBH4-InCl3 System

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Chinese Journal of Chemistry 2006年第6期24卷 807-810页

作者： RAVI, Varala RAMU, Enugala vijay kumar, Ponnamaneni SRINIVAS RAO, Adapa Indian Institute of Chemical Technology Hyderabad-500 007 India

A combination of sodium borohydride and a catalytic amount of indium（Ⅲ） chloride in acetonitrile reduces imines formed in-situ from aldehydes and amines to the corresponding functionalised secondary and tertiary amines in moderate to good yields. Noteworthy is that highly chemoselective reactions were achieved in the presence of other functional groups such as halogens, carbon-carbon double bonds and hydroxyl groups.

关键词： NaBH4-InCl3 aldehyde amine One Pot Reduction

Extent of mismatch between the period of circadian clocks and light/dark cycles determines time-to-emergence in fruit flies

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Insect Science 2015年第4期22卷 569-577页

作者： Pankaj Yadav Deepak Choudhury Madhumala K. Sadanandappa vijay kumar Sharma Chronobiology Laboratory Evolutionary and Organismal Biology Unit Jawaharlal Nehru Centre for Advanced Scientific Research Bangalore 560064 Kamataka India

Circadian clocks time developmental stages of fruit flies Drosophila melanogaster, while light/dark （LD） cycles delimit emergence of adults, conceding only during the ＂allowed gate.＂ Previous studies have revealed that time-to-emergence can be altered by mutations in the core clock gene period （per）, or by altering the length of LD cycles. Since this evidence came from studies on genetically manipulated flies, or on flies maintained under LD cycles with limited range of periods, inferences that can be drawn are limited. Moreover, the extent of shortening or lengthening of time-to-emergence re- mains yet unknown. In order to pursue this further, we assayed time-to-emergence of D. rnelanogaster under 12 different LD cycles as well as in constant light （LL） and constant dark conditions （DD）. Time-to-emergence in flies occurred earlier under LL than in LD cycles and DD. Among the LD cycles, time-to-emergence occurred earlier under T4-T8, followed by T36-T48, and then T12-T32, suggesting that egg-to-emergence duration in flies becomes shorter when the length of LD cycles deviates from 24 h, bearing a strong positive and a marginally negative correlation with day length, for values shorter and longer than 24 h, respectively. These results suggest that the extent of mismatch between the period of circadian clocks and environmental cycles determines the time-to-emergence in Drosophila.

关键词： circadian Drosophila light/dark regimes period time-to-emergence

Conservation Strategy for African Medicinal Species: In Vitro Biotechnological Approach

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Phyton-International Journal of Experimental Botany 2020年第4期89卷 779-794页

作者： Priyanka Jha Swati Chahal Devendra kumar Pandey Joginder Singh Ram Prasad vijay kumar Amity Institute of Biotechnology Amity UniversityKolkataWest Bengal700156India Plant Biotechnology Laboratory Division of Research and DevelopmentLovely Professional UniversityPhagwara144411PunjabIndia Department of Biotechnology School of Bioengineering and BiosciencesLovely Professional UniversityPhagwara144411PunjabIndia Department of Microbiology School of Bioengineering and BiosciencesLovely Professional UniversityPhagwara144411PunjabIndia Department of Botany School of Life SciencesMahatma Gandhi Central UniversityMotihariBihar845401India

The use of medicinal plants for different therapeutic values is well documented in African *** diverse biodiversity hotspots provide a wide range of endemic species,which ensures a potential medicinal *** feasible conservation approach and sustainable harvesting for the medicinal species remains a huge ***,conservation approach through different biotechnological tools such as micropropagation,somatic embryogenesis,synthetic seed production,hairy root culture,molecular markers based study and cryopreservation of endemic African medicinal species is much *** this review,an attempt has been made to provide different in vitro biotechnological approaches for the conservation of African medicinal *** present review will be helpful in further technology development and deciding the priorities at decision-making levels for in vitro conservation and sustainable use of African medicinal species.

关键词： Biotechnological approach conservation medicinal plant African traditional medicine(ATM) start codon targeted polymorphism(SCoT) somatic embryogenesis

Enhanced Field-Based Detection of Potato Blight in Complex Backgrounds Using Deep Learning

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Plant Phenomics 2021年第1期3卷 209-221页

作者： Joe Johnson Geetanjali Sharma Srikant Srinivasan Shyam kumar Masakapalli Sanjeev Sharma Jagdev Sharma vijay kumar Dua School of Computing&Electrical Engineering Indian Institute of Technology MandiKamandH.P.India BioX Center School of Basic SciencesIndian Institute of Technology MandiKamandH.P.India ICAR-Central Potato Research Institute H.P.ShimlaIndia

Rapid and automated identification of blight disease in potato will help farmers to apply timely remedies to protect their *** detection of blight disease can be cumbersome and may require trained *** overcome these issues,we present an automated system using the Mask Region-based convolutional neural network(Mask R-CNN)architecture,with residual network as the backbone network for detecting blight disease patches on potato leaves in field *** approach uses transfer learning,which can generate good results even with small *** model was trained on a dataset of 1423 images of potato leaves obtained from fields in different geographical locations and at different times of the *** images were manually annotated to create over 6200 labeled patches covering diseased and healthy portions of the *** Mask R-CNN model was able to correctly differentiate between the diseased patch on the potato leaf and the similar-looking background soil patches,which can confound the outcome of binary *** improve the detection performance,the original RGB dataset was then converted to HSL,HSV,LAB,XYZ,and YCrCb color spaces.A separate model was created for each color space and tested on 417 field-based test *** yielded 81.4%mean average precision on the LAB model and 56.9%mean average recall on the HSL model,slightly outperforming the original RGB color space *** analysis of the detection performance indicates an overall precision of 98%on leaf images in a field environment containing complex backgrounds.

关键词： Deep network backbone