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Thermodynamic behaviour of Rashba quantum dot in the presence of magnetic field

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Chinese physics B 2016年第5期25卷 262-267页

作者： Sukirti Gumber Manoj kumar pradip kumar Jha Man mohan Department of physics & Astrophysics University of Delhi Department of physics DDU College University of Delhi

The thermodynamic properties of an In Sb quantum dot have been investigated in the presence of Rashba spin–orbit interaction and a static magnetic field. The energy spectrum and wave-functions for the system are obtained by solving the Schrodinger wave-equation analytically. These energy levels are employed to calculate the specific heat, entropy,magnetization and susceptibility of the quantum dot system using canonical formalism. It is observed that the system is susceptible to maximum heat absorption at a particular value of magnetic field which depends on the Rashba coupling parameter as well as the temperature. The variation of specific heat shows a Schottky-like anomaly in the low temperature limit and rapidly converges to the value of 2kB with the further increase in temperature. The entropy of the quantum dot is found to be inversely proportional to the magnetic field but has a direct variation with temperature. The substantial effect of Rashba spin–orbit interaction on the magnetic properties of quantum dot is observed at low values of magnetic field and temperature.

关键词： quantum dot Rashba spin–orbit interaction thermal and magnetic properties

Recent advances in catalytic combustion of Ap-based composite solid propellants

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Defence Technology（防务技术） 2021年第3期17卷 1013-1031页

作者： Narendra Yadav prem kumar Srivastava mohan Varma Department of Space Engineering&Rocketry India Department of Chemistry Birla Institute of TechnologyMesraRanchiIndia

Composite solid propellants(CSps) have widely been used as main energy source for propelling the rockets in both space and military applications. Internal ballistic parameters of rockets like characteristic exhaust velocity, specific impulse, thrust, burning rate etc., are measured to assess and control the performance of rocket motors. The burn rate of solid propellants has been considered as most vital parameter for design of solid rocket motors to meet specific mission requirements. The burning rate of solid propellants can be tailored by using different constituents, extent of oxidizer loading and its particle size and more commonly by incorporating suitable combustion catalysts. Various metal oxides(MOs),complexes, metal powders and metal alloys have shown positive catalytic behaviour during the combustion of CSps. These are usually solid-state catalysts that play multiple roles in combustion of CSps such as reduction in activation energy, enhancement of rate of reaction, modification of sequences in reaction-phase, influence on condensed-phase combustion and participation in combustion process in gas-phase reactions. The application of nanoscale catalysts in CSps has increased considerably in recent past due to their superior catalytic properties as compared to their bulk-sized counterparts. A large surface-to-volume ratio and quantum size effect of nanocatalysts are considered to be plausible reasons for improving the combustion characteristics of propellants. Several efforts have been made to produce nanoscale combustion catalysts for advanced propellant formulations to improve their energetics. The work done so far is largely scattered. In this review, an effort has been made to introduce various combustion catalysts having at least a metallic entity. Recent developments of nanoscale combustion catalysts with their specific merits are discussed. The combustion chemistry of a typical CSp is briefly discussed for providing a better understanding on role of co

关键词： Composite solid propellants Burn rate modifier Metallic nano-catalysts Catalytic combustion Thermal decomposition

VARIABLE MESH FINITE DIFFERENCE METHOD FOR SELF-ADJOINT SINGULARLY pERTURBED TWO-pOINT BOUNDARY VALUE pROBLEMS

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Journal of Computational Mathematics 2010年第5期28卷 711-724页

作者： mohan K.Kadalbajoo Devendra kumar Department of Mathematics & Statistics

A numerical method based on finite difference method with variable mesh is given for self-adjoint singularly perturbed two-point boundary value problems. To obtain parameter- uniform convergence, a variable mesh is constructed, which is dense in the boundary layer region and coarse in the outer region. The uniform convergence analysis of the method is discussed. The original problem is reduced to its normal form and the reduced problem is solved by finite difference method taking variable mesh. To support the efficiency of the method, several numerical examples have been considered.

关键词： Singularly perturbed boundary value problems Finite difference method,Boundary layer parameter uniform-convergence Variable mesh.

Impact of frailty on endoscopic retrograde cholangiopancreatography outcomes in nonagenarians:A United States national experience

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World Journal of Gastrointestinal Endoscopy 2024年第3期16卷 148-156页

作者： Sanket Dhirubhai Basida Dushyant Singh Dahiya Muhammad Nadeem Yousaf Brinda Basida Bhanu Siva mohan pinnam Manesh kumar Gangwani Hassam Ali Sahib Singh Yash R Shah Daksh Ahluwalia Mihir prakash Shah Saurabh Chandan Neil R Sharma Shyam Thakkar Department of Internal Medicine University of Missouri-ColumbiaColumbiaMO 65212United States Division of Gastroenterology Hepatology&MotilityThe University of Kansas School of MedicineKansas CityKS 66160United States Division of Gastroenterology and Hepatology University of MissouriColumbiaMO 65212United States Department of Rheumatology Medical College of GeorgiaAugusta UniversityNorth AugustaGA 30912United States Department of Internal Medicine John H.Stroger Hospital of Cook CountyChicagoIL 60612United States Department of Internal Medicine The University of ToledoToledoOH 43606United States Division of Gastroenterology and Hepatology East Carolina University/Brody School of MedicineGreenvilleNC 27858United States Department of Internal Medicine Sinai HospitalBaltimoreMD 21215United States Department of Internal Medicine Trinity Health Oakland/Wayne State UniversityPontiacMI 48341United States Division of Gastroenterology and Hepatology Creighton University School of MedicineOmahaNE 68131United States Division of Interventional Oncology&Surgical Endoscopy GI Oncology Tumor Site TeamParkview Cancer InstituteParkview HealthFort WayneIN 46845United States Section of Gastroenterology&Hepatology West Virginia University School of MedicineMorgantownWV 26505United States

BACKGROUND Endoscopic retrograde cholangiopancreatography(ERCp)is an essential therapeutic tool for biliary and pancreatic *** and elderly patients,especially those aged≥90 years are generally considered a higher-risk population for ERCp-related *** To investigate outcomes of ERCp in the Non-agenarian population(≥90 years)concerning *** This is a cohort study using the 2018-2020 National Readmission *** aged≥90 were identified who underwent ERCp,using the international classification of diseases-10 code with clinical *** Hopkins’s adjusted clinical groups frailty indicator was used to classify patients as frail and *** primary outcome was mortality,and the secondary outcomes were morbidity and the 30 d readmission rate related to *** used univariate and multivariate regression models for *** A total of 9448 patients were admitted for any indications of *** and non-frail patients were 3445(36.46%)and 6003(63.53%)*** for ERCp were Choledocholithiasis(74.84%),Biliary pancreatitis(9.19%),pancreatico-biliary cancer(7.6%),Biliary stricture(4.84%),and Cholangitis(1.51%).Mortality rates were higher in frail group[adjusted odds ratio(aOR)=1.68,p=0.02].The Intra-procedural complications were insigni-ficant between the two groups which included bleeding(aOR=0.72,p=0.67),accidental punctures/lacerations(aOR=0.77,p=0.5),and mechanical ventilation rates(aOR=1.19,p=0.6).post-ERCp complication rate was similar for bleeding(aOR=0.72,p=0.41)and post-ERCp pancreatitis(aOR=1.4,p=0.44).Frail patients had a longer length of stay(6.7 d vs 5.5 d)and higher mean total charges of hospitalization($78807 vs$71392)compared to controls(ppatients were similar(p=0.96).CONCLUSION There was a significantly higher mortality risk and healthcare burden amongst nonagenarian frail patients undergoing ERCp compared

关键词： Endoscopic retrograde cholangiopancreatography Nonagenarians Frailty Mortality Healthcare burden

Soft Computing Based Discriminator Model for Glaucoma Diagnosis

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Computer Systems Science & Engineering 2022年第9期42卷 867-880页

作者： Anisha Rebinth S.mohan kumar Department of Information Science and Engineering NHCEVisvesvaraya Technological UniversityBangaloreIndia Department of Computer Science and Engineering Nagarjuna College of Engineering and TechnologyBangaloreIndia

In this study, a Discriminator Model for Glaucoma Diagnosis (DMGD)using soft computing techniques is presented. As the biomedical images such asfundus images are often acquired in high resolution, the Region of Interest (ROI)for glaucoma diagnosis must be selected at first to reduce the complexity of anysystem. The DMGD system uses a series of pre-processing;initial cropping by thegreen channel’s intensity, Spatially Weighted Fuzzy C Means (SWFCM), bloodvessel detection and removal by Gaussian Derivative Filters (GDF) and inpaintingalgorithms. Once the ROI has been selected, the numerical features such as colour, spatial domain features from Local Binary pattern (LBp) and frequencydomain features from LAWS are generated from the corresponding ROI forfurther classification using kernel based Support Vector Machine (SVM). TheDMGD system performances are validated using four fundus image databases;ORIGA, RIM-ONE, DRISHTI-GS1, and HRF with four different kernels;LinearKernel (LK), polynomial Kernel (pK), Radial Basis Function (RBFK) kernel,Quadratic Kernel (QK) based SVM classifiers. Results show that the DMGD system classifies the fundus images accurately using the multiple features and kernelbased classifies from the properly segmented ROI.

关键词： Glaucoma support vector classification clustering technique spatial domain and frequency domain features

Optimal and Effective Resource Management in Edge Computing

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Computer Systems Science & Engineering 2023年第2期44卷 1201-1217页

作者： Darpan Majumder S.mohan kumar Department of Information Science and Engineering New Horizon College of Engineering Research CentreVisvesvaraya Technological University(VTU)BangaloreIndia Department of CSE Nagarjuna College of Engineering and TechnologyBangaloreIndia

Edge computing is a cloud computing extension where physical compu-ters are installed closer to the device to minimize *** task of edge data cen-ters is to include a growing abundance of applications with a small capability in comparison to conventional data *** this framework,Federated Learning was suggested to offer distributed data training strategies by the coordination of many mobile devices for the training of a popular Artiﬁcial Intelligence(AI)model without actually revealing the underlying data,which is signiﬁcantly enhanced in terms of *** learning(FL)is a recently developed decentralized profound learning methodology,where customers train their localized neural network models independently using private data,and then combine a global model on the core server *** models on the edge server use very little time since the edge server is highly *** the amount of time it takes to download data from smartphone users on the edge server has a signiﬁcant impact on the time it takes to complete a single cycle of FL operations.A machine learning strategic planning system that uses FL in conjunction to minimise model training time and total time utilisation,while recognising mobile appliance energy restrictions,is the focus of this *** further speed up integration and reduce the amount of data,it implements an optimization agent for the establishment of optimal aggregation policy and asylum architecture with several employees’shared *** main solutions and lessons learnt along with the prospects are *** show that our method is superior in terms of the effective and elastic use of resources.

关键词： Federated learning machine learning edge computing resource management

Effect of Surface Roughness on Laser Induced Nonlinear Optical properties of Annealed ZnO Thin Films

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Journal of Materials Science & Technology 2012年第6期28卷 506-511页

作者： Vinay kumari Vinod kumar Devendra mohan purnima B.p.Malik R.M.Mehra Department of physics BMIETSonepat 131001India Department of physics DCRUSTMurthal 131027India Materials Science Group Inter University Accelerator CentreAruna Asaf Ali MargNew Delhi 110067India Department of Applied physics GJUS&THisar 125001India School of Engineering and Technology Sharda UniversityGreater Noida 201306India

Variation of nonlinear optical properties with surface roughness of ZnO thin films deposited on coming glass substrates at different annealing temperature （TA） was reported. The films were characterized by X-ray diffraction （XRD）, UV-Vis-NIR transmission and single beam z-scan technique using second harmonics of Nd：YAG laser. Surface morphology of the samples was investigated by atomic force microscopy （AFM）. Surface roughness was found minimum （8.4 nm） for ZnO sample annealed at 450℃. The nonlinear optical properties （NLO） were found to be dependent on surface roughness and the highest value of third order nonlinear susceptibility （X（3）=4.3x 10-7 esu） was obtained for ZnO at TA 450℃.

关键词： ZnO films Sol-gel Annealing temperature Nonlinear optical properties Thirdorder nonlinear susceptibility z-scan

Skin Lesion Classification System Using Shearlets

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Computer Systems Science & Engineering 2023年第1期44卷 833-844页

作者： S.mohan kumar T.Kumanan Department of Computer Science and Engineering Meenakshi Academy of Higher Education and ResearchChennai600078Tamil NaduIndia

The main cause of skin cancer is the ultraviolet radiation of the *** spreads quickly to other body ***,early diagnosis is required to decrease the mortality rate due to skin *** this study,an automatic system for Skin Lesion Classification(SLC)using Non-Subsampled Shearlet Transform(NSST)based energy features and Support Vector Machine(SVM)classifier is ***,the NSST is used for the decomposition of input skin lesion images with different directions like 2,4,8 and *** the NSST’s sub-bands,energy fea-tures are extracted and stored in the feature database for *** classifier is used for the classification of skin lesion *** dermoscopic skin images are obtained from pH^(2) database which comprises of 200 dermoscopic color images with melanocytic *** performances of the SLC system are evaluated using the confusion matrix and Receiver Operating Characteristic(ROC)*** SLC system achieves 96%classification accuracy using NSST’s energy fea-tures obtained from 3^(rd) level with 8-directions.

关键词： Skin lesion classification non-subsampled shearlet transform sub-band coefficients energy feature support vector machine

Impact of Land-Use Change on Soil Microbial Community Composition and Organic Carbon Content in the Dry Tropics

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pedosphere 2017年第5期27卷 974-977页

作者： Chandra mohan kumar Nandita GHOSHAL Centre of Advanced Study in Botany Department of Botany Institute of Science Banaras Hindu University

Restoration of forests poses a major challenge globally, particularly in the tropics, as the forests in these regions are more vulnerable to land-use change. We studied land-use change from natural forest(NF) to degraded forest(DF), and subsequently to either Jatropha curcas plantation(Jp) or agroecosystem(AG), in the dry tropics of Uttar pradesh, India, with respect to its impacts on soil microbial community composition as indicated by phospholipid fatty acid(pLFA) biomarkers and soil organic carbon(SOC) content. The trend of bacterial pLFAs across all land-use types was in the order: NF > Jp > DF> AG. In NF, there was dominance of gram-negative bacterial(G^-) pLFAs over the corresponding gram-positive bacterial(G^+) pLFAs. The levels of G^- pLFAs in AG and Jp differed significantly from those in DF, whereas those of G^+ pLFAs were relatively similar in these three land-use types. Fungal pLFAs,however, followed a different trend: NF > Jp > DF = AG. Total pLFAs, fungal/bacterial(F/B) pLFA ratio, and SOC content followed trends similar to that of bacterial pLFAs. Across all land-use types, there were strong positive relationships between SOC content and G-, bacterial, fungal, and total microbial pLFAs and F/B pLFA ratio. Compared with bacterial pLFAs, fungal pLFAs appeared to be more responsive to land-use change. The F/B pLFA ratio, fungal pLFAs, and bacterial pLFAs explained 91%, 94%,and 73% of the variability in SOC content, respectively. The higher F/B pLFA ratio in Jp favored more soil C storage, leading to faster ecosystem recovery compared to either AG or DF. The F/B pLFA ratio could be used as an early indicator of ecosystem recovery in response to disturbance, particularly in relation to land-use change.

关键词： ecosystem recovery fungal/bacterial ratio natural forest phospholipid fatty acid (pLFA) plantation