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Microstructures and mechanical properties of nanocrystalline NiTi intermetallics formed by mechanosynthesis

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International Journal of Minerals,Metallurgy and Materials 2018年第1期25卷 80-87页

作者： S.arunkumar P.Kumaravel C.Velmurugan V.Senthilkumar Vinayaka Mission's Kimpananda Variyar Engineering College Salem 636308TamilnaduIndia Institute of road and Transport Technology Erode 638316TamilnaduIndia National Institute of Technology Trichy 620015TamilnaduIndia

The formulation of nanocrystallinc NiTi shape memory alloys has potential effects in mechanical stimulation and medical im- plantology. The present work elucidates the effect of milling time on the product＇s structural characteristics, chemical composition, and mi- crohardness for NiTi synthesized by mechanical alloying for different milling durations. Increasing the milling duration led to the formation of a nanocrystalline NiTi intermetallic at a higher level. The formation of nanocrystalline materials was directed through cold fusion, fractur- ing, and the development of a steady state, which were influenced by the accumulation of strain energy. In the morphological study, uninter- rupted cold diffusion and fracturing were visualized using transmission electron microscopy. Particle size analysis revealed that the mean particle size was reduced to -93 μm after 20 h of milling. The mechanical strength was enhanced by the formation of a nanocrystalline in- termetallic phase at longer milling time, which was confirmed by the results of Vickers hardness analyses.

关键词： nickel-titanium shape memory alloy lattice strain nano-crystalline mechanical alloying microstructural characterization

Optimum Design of Stair-Climbing robots Using Taguchi Method

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Intelligent Automation & Soft Computing 2023年第1期35卷 1229-1244页

作者： A.arunkumar S.ramabalan D.Elayaraja Department of Mechanical Engineering E.G.S.Pillay Engineering CollegeNagapattinamTamilnaduIndia Department of Mechanical Engineering QIS College of Engineering and TechnologyOngoleAndhra PradeshIndia

Environmental issues like pollution are major threats to human *** systems are developed to reduce *** this paper,an optimal mobile robot design to reduce pollution in Green supply chain management *** supply chain management involves as similating environmentally and eco-nomically feasible solutions into the supply chain ***,advanced technologies,and advanced networks are becoming pillars of a sustainable supply chain management *** the same time,there is much change happening in the logistics *** are moving towards a new logistics *** the new model,robotic logistics has a vital *** reasons for this change are the rapid growth of the e-commerce business and the shortage of *** advantages of using robotic logistics are reduction in human errors,faster delivery speed,better customer satisfaction,more safety for workers,and high workforce adaptability.A robot with rocker-bogie suspension is a six-wheeled mobile platform that has a distinctive potential to keep all wheels on the ground *** has been designed to traverse rough and uneven terrain by distributing the load over its wheels ***,there is a limitation to achieving high-speed mobility against vertical *** this research,an optimal design of product delivery wheeled robots for a sustainable supply chain system is proposed to ensure higher adaptability and maximum stability during climbing *** design parameters of the proposed robot are optimized using Taguchi *** aim is to get a smooth trajectory of the robot’s *** proposed approach realizes a robot with much-improved stability which can climb over heights more than the size of the wheel(i.e.,3 times the radius of wheels).The results reveal that the modified rocker-bogie system not only increases the stair-climbing capability but also thwarts instability due to overturning of a wheel of the robot.

关键词： Green supply chain management robotic logistics stair-climbing wheeled mobile robot optimum design rocker-bogie mechanism taguchi method

COVID-19: An overview and a clinical update

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World Journal of Clinical Cases 2021年第1期9卷 8-23页

作者： arunkumar Krishnan James P Hamilton Saleh A Alqahtani Tinsay A Woreta Division of Gastroenterology and Hepatology Johns Hopkins School of MedicineBaltimoreMD 21287United States Liver Transplant Center King Faisal Specialist Hospital&Research CenterRiyadh 12713Saudi Arabia

The outbreak of coronavirus disease-2019(COVID-19,previously known as 2019 nCoV)caused by severe acute respiratory syndrome coronavirus 2(SArS-CoV-2)infection in Wuhan City,China,has spread rapidly around the *** patients from the first cluster had an epidemiological connection to the Wuhan's Huanan Seafood Wholesale *** evidence has shown that SArSCoV-2 can be easily transmitted from person to person through close contact and respiratory droplets,posing a substantial challenge to public *** present,the research on SArS-CoV-2 is still in the primary ***,dexamethasone and remdesivir are appeared to be promising medical ***,there is no definite specific treatment,and the mainstay of treatment is still focused on supportive ***,over 150 vaccines are under *** is necessary to understand the nature of the virus and its clinical characteristics in order to find effectively manage the *** knowledge about this virus is rapidly evolving,and clinicians must update themselves *** present review comprehensively summarizes the epidemiology,pathogenesis,clinical characteristics,and management of COVID-19 based on the current evidence.

关键词： Coronaviruses COVID-19 SArS-CoV-2 Epidemiology Symptoms Laboratory Imaging Treatment Vaccines Prevention

A Novel Cluster Analysis-Based Crop Dataset recommendation Method in Precision Farming

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Computer Systems Science & Engineering 2023年第9期46卷 3239-3260页

作者： K.r.Naveen Kumar Husam Lahza B.r.Sreenivasa Tawfeeq Shawly Ahmed A.Alsheikhy H.arunkumar C.r.Nirmala Department of Computer Science&Engineering Bapuji Institute of Engineering&TechnologyDavangereKarnatakaIndia Department of Information Technology Faculty of Computing and Information TechnologyKing Abdulaziz UniversityJeddahSaudi Arabia Department of Information Science&Engineering Bapuji Institute of Engineering&TechnologyDavangereKarnatakaIndia Department of Electrical Engineering Faculty of Engineering at RabighKing Abdulaziz UniversityJeddahSaudi Arabia Department of Electrical Engineering College of EngineeringNorthern Border UniversityArarSaudi Arabia

Data mining and analytics involve inspecting and modeling large pre-existing datasets to discover decision-making *** agriculture uses datamining to advance agricultural *** farmers aren’t getting the most out of their land because they don’t use precision *** harvest crops without a well-planned recommendation *** crop production is calculated by combining environmental conditions and management behavior,yielding numerical and categorical *** existing research still needs to address data preprocessing and crop categorization/***,statistical analysis receives less attention,despite producing more accurate and valid *** study was conducted on a dataset about Karnataka state,India,with crops of eight parameters taken into account,namely the minimum amount of fertilizers required,such as nitrogen,phosphorus,potassium,and pH *** research considers rainfall,season,soil type,and temperature parameters to provide precise cultivation recommendations for high *** presented algorithm converts discrete numerals to factors first,then reduces ***,the algorithm generates six datasets,two fromCase-1(dataset withmany numeric variables),two from Case-2(dataset with many categorical variables),and one from Case-3(dataset with reduced factor variables).Finally,the algorithm outputs a class membership allocation based on an extended version of the K-means partitioning method with lambda *** presented work produces mixed-type datasets with precisely categorized crops by organizing data based on environmental conditions,soil nutrients,and ***,the prepared dataset solves the classification problem,leading to a model evaluation that selects the best dataset for precise crop prediction.

关键词： Data mining crop prediction k-prototypes k-means cluster machine learning

Sensitivity of digital elevation models:The scenario from two tropical mountain river basins of the Western Ghats,India

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Geoscience Frontiers 2014年第6期5卷 893-909页

作者： Jobin Thomas Sabu Joseph K.P.Thrivikramji K.S.arunkumar Inter University Centre for Geospatial Information Science and Technology University of KeralaThiruvananthapuramKeralaIndia Department of Environmental Sciences University of KeralaThiruvananthapuramKeralaIndia Department of Geology University of KeralaThiruvananthapuramKeralaIndia Department of Geology MES CollegePonnaniMalappuramKeralaIndia

The paper evaluates sensitivity of various spaceborne digital elevation models （DEMs）, viz., Advanced Spaceborne Thermal Emission and reflection radiometer （ASTEr）, Shuttle radar Topography Mapping Mission （SrTM） and Global Multi-resolution Terrain Elevation Data 2010 （GMTED）, in comparison with the DEM （TOPO） derived from contour data of 20 m interval of Survey of India topographic sheets of 1 ： 50,000 scale. Several topographic attributes, such as elevation （above mean sea level）, relative relief, slope, aspect, curvature, slope-length and -steepness （LS） factor, terrain ruggedness index （TrI）, topo- graphic wetness index （TWI）, hypsometric integral （lhyp） and drainage network attributes （stream number and stream length） of two tropical mountain river basins, viz. Muthirapuzha river Basin and Pambar river Basin are compared to evaluate the variations. Though the basins are comparable in extent, they differ in respect of terrain characteristics and climate. The result.,; suggest that ASTEr and SrTM provide equally reliable representation of topography portrayed by TOP（） and the topographic attributes extracted from the spaceborne DEMs are in agreement with those derived from TOPO. Despite the coarser resolution, SrTM shows relatively higher vertical accuracy （rMSE -- 23 and 20 m respectively in MrB and PrB） compared to ASTEr （rMSE - 33 and 24 m） and GMTED （rMSE - 59 and 48 m）. Vertical accuracy of all the spaceborne DEMs is influenced by relief of the terrain as well as type of vegetation. Further, GMTED shows significant deviation for most of the attributes, indicating its inability for mountain-river-basin-scale studies.

关键词： DEM ASTEr SrTM GMTEDTropical mountain river basins Western Ghats

Healthcare Monitoring Using Ensemble Classifiers in Fog Computing Framework

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Computer Systems Science & Engineering 2023年第5期45卷 2265-2280页

作者： P.M.arunkumar Mehedi Masud Sultan Aljahdali Mohamed Abouhawwash Department of Computer Science and Engineering Karpagam College of EngineeringCoimbatore641032India Department of Computer Science College of Computers and Information TechnologyTaif UniversityP.O.Box 11099Taif21944Saudi Arabia Department of Mathematics Faculty of ScienceMansoura UniversityMansoura35516Egypt Department of Computational Mathematics Scienceand Engineering(CMSE)Michigan State UniversityEast LansingMI48824USA

Nowadays,the cloud environment faces numerous issues like synchronizing information before the switch over the data *** requirement for a centralized internet of things(IoT)-based system has been restricted to some *** to low scalability on security considerations,the cloud seems *** healthcare networks demand computer operations on large amounts of data,the sensitivity of device latency evolved among health networks is a challenging *** comparison to cloud domains,the new paradigms of fog computing give fresh alternatives by bringing resources closer to users by providing low latency and energy-efficient data processing *** fog computing frameworks have various flaws,such as overvaluing response time or ignoring the accuracy of the result yet handling both at the same time compromises the network *** this proposed work,Health Fog is integrated with the Optimized Cascaded Convolution Neural Network framework for diagnosing heart ***,the data is collected,and then pre-processing is done by Linear Discriminant *** the features are extracted and optimized using Galactic Swarm *** optimized features are given into the Health Fog framework for diagnosing heart disease *** uses ensemble-based deep learning in edge computing devices,which automatically monitors real-life health networks such as heart disease ***,the classifiers such as bagging,boosting,XGBoost,Multi-Layer Perceptron(MLP),and Partitions(PArT)are used for classifying the *** the majority voting classifier predicts the *** work uses FogBus architecture and evaluates the execution of power usage,bandwidth of the network,latency,execution time,and accuracy.

关键词： Healthfog FogBus cascaded convolution neural network cloud computing heart disease automatic health monitoring internet of things

Elevated Liver Enzymes along with Comorbidity Is a High risk Factor for COVID-19 Mortality:A South Indian Study on 1,512 Patients

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Journal of Clinical and Translational Hepatology 2022年第1期10卷 120-127页

作者： Narayanasamy Krishnasamy Karthick rajendran Parimita Barua arunkumar ramachandran Priyadarshini Panneerselvam Muthukumaran rajaram Institute of Hepatobiliary Sciences Madras Medical College and Rajiv Gandhi Government General HospitalChennaiTamil NaduIndia Multidisciplinary research Unit(MrU) Madras Medical CollegeChennaiTamil NaduIndia

Background and Aims:Liver enzyme abnormalities in coronavirus 2019(COVID-19)are being addressed in the *** predictive risk of elevated liver enzymes has not been established for COVID-19 *** this study,we hypothesized that elevated liver enzymes at ad-mission can predict the outcome of COVID-19 disease with other known indicators,such as ***:This retrospective study included all the consecutive hos-pitalized patients with confirmed COVID-19 disease from March 4th to May 31st,*** study was conducted in rajiv Gandhi Government General Hospital,Chennai,Ta-mil Nadu,*** assessed demography,clinical vari-ables,COVID-19 severity,laboratory parameters,and ***:We included 1,512 patients,and median age was 47 years(interquartile range:34-60)with 36.9%being *** enzyme level(aspartate aminotrans-ferase and/or alanine aminotransferase)was elevated in 450/1,512(29.76%)*** was present in 713/1,512(47.16%)*** with liver enzymes’elevation and presence of comorbidity were older,more frequently hospitalized in ICU and had more severe symp-toms of COVID-19 at the time of *** of liver enzymes’elevation with comorbidity was a high risk factor for death(Or:5.314,95%CI:2.278-12.393),as compared to patients with presence of comorbidity(Or:4.096,95%CI:1.833-9.157).Conclusions:Comorbid-ity combined with liver enzymes’elevation at presentation independently increased the risk of death in COVID-19 by at least 5-fold.

关键词： COVID-19 SArS-CoV-2 Liver enzyme Comorbidity Aspartate aminotransferase Alanine aminotransferase

Tribological and vibrational characteristics of AISI 316L tested at elevated temperature and 600 Torr vacuum

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Defence Technology（防务技术） 2019年第1期15卷 58-64页

作者： K.Arul raj M.P.arunkumar P.K.C.Kanigalpula M.Karthikeyan Department of Mechanical Engineering Koneru Lakshmaiah Education Foundation Department of Mechanical Engineering RajaRajeswari College of Engineering

Friction and wear studies enable the investigation of material interaction between two sliding surfaces in contact. In the present investigation, the coefficient of friction and the wear resistance of AISI 316 L parts were studied under self-mating, dry sliding conditions using a pin-on-disc type configuration. The experiments were conducted at vacuum based high temperature pin-on-disc tribometer. The 4 mm diameter pin and 180 mm diameter disc were subjected to varying sliding velocities(0.5, 0.75 and 1.5 m/s) and were operated in 200, 400, 500 and 580 ℃ temperature at 600 Torr vacuum. The variation of specific wear rates with sliding velocities and different environmental conditions was studied. The morphology of sliding/rubbed surfaces was observed using Scanning Electron Microscope. In summary, it was found that a severe to mild wear transition occurred in sliding under operating conditions. Increased wear rates have been observed for 500 and 580 ℃ with increasing sliding velocity. Adhesive wear has been found to be predominant at 500 and 580 ℃ where as de-lamination has been observed at ambient temperature,200 and 400 ℃ in vacuum. The present paper also carried out the numerical analysis of the vibration behavior of AISI 316 L under thermal environment. results revealed that at high temperature vibrational amplitude and natural frequency is significantly reduced. This can be attributed to the reduction in stiffness of the material at elevated temperatures. This high amplitude vibration during service can lead to high wear rate.

关键词： Pin-on-disc Sliding wear Vacuum De-lamination Scanning electron microscope Vibration

Pitfalls and optimal approaches to diagnose melioidosis

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Asian Pacific Journal of Tropical Medicine 2016年第6期9卷 501-510页

作者： Paul Vijay Kingsley Govindakarnavar arunkumar Meghan Tipre Mark Leader Nalini Sathiakumar Sultan Ismail Hospital Manipal Center for Virus research Manipal University School of Public Health University of Alabama at Birmingham

Melioidosis is a severe and fatal infectious disease in the tropics and subtropics. It presents as a febrile illness with protean manifestation ranging from chronic localized infection to acute fulminant septicemia with dissemination of infection to multiple organs characterized by abscesses. Pneumonia is the most common clinical presentation. Because of the wide range of clinical presentations, physicians may often misdiagnose and mistreat the disease for tuberculosis, pneumonia or other pyogenic infections. The purpose of this paper is to present common pitfalls in diagnosis and provide optimal approaches to enable early diagnosis and prompt treatment of melidoidosis. Melioidosis may occur beyond the boundaries of endemic areas. There is no pathognomonic feature specific to a diagnosis of melioidosis. In endemic areas, physicians need to expand the diagnostic work-up to include melioidosis when confronted with clinical scenarios of pyrexia of unknown origin, progressive pneumonia or sepsis. radiological imaging is an integral part of the diagnostic workup. Knowledge of the modes of transmission and risk factors will add support in clinically suspected cases to initiate therapy. In situations of clinically highly probable or possible cases where laboratory bacteriological confirmation is not possible, applying evidence-based criteria and empirical treatment with antimicrobials is recommended. It is of prime importance that patients undergo the full course of antimicrobial therapy to avoid relapse and recurrence. Early diagnosis and appropriate management is crucial in reducing serious complications leading to high mortality, and in preventing recurrences of the disease. Thus, there is a crucial need for promoting awareness among physicians at all levels and for improved diagnostic microbiology services. Further, the need for making the disease notifiable and/or initiating melioidosis registries in endemic countries appears to be compelling.

关键词： Melioidosis pseudomallei review Diagnosis Treatment Pitfalls Approaches route of infection