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Numerical modelling of pullout of helical soil nail

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Journal of Rock Mechanics and Geotechnical Engineering 2017年第4期9卷 648-658页

作者： Saurabh Rawat ashok kumar gupta Department of Civil Engineering Jaypee University of Information Technology Waknaghat Solan 173234 India

An investigation into the pullout response of helical soil nail using finite element subroutine Plaxis 2D is *** numerical modelling of actual pullout response is achieved by axisymmetric and horizontal loading *** effect of varying number of helical plates,helical plate spacing and helical plate diameter is studied to understand the pullout capacity *** failure surfaces for various helical soil nail configurations and their pullout mechanisms are also analysed and *** pullout capacity is found to increase with increase in number of helical *** helical plate spacing ratio（s/D;） and diameter ratio（D;/D;） are found to increase the pullout only up to a critical *** response of helical soil nail using axisymmetric finite element simulation is found similar to the uplift behaviour of helical piles and helical soil *** the absence of literature regarding numerical modelling of helical soil nail,simulation results are validated with uplift responses of helical piles and soil anchors.A good agreement in their comparative study for pullout response is also observed.

关键词： Finite element Helical soil nail Pullout response Plate spacing Plate diameter Failure mechanism

Pullout of soil nail with circular discs: A three-dimensional finite element analysis

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Journal of Rock Mechanics and Geotechnical Engineering 2017年第5期9卷 967-980页

作者： Saurabh Rawat ashok kumar gupta Anil kumar Department of Civil Engineering Jaypee University of Information Technology Waknaghat Solan 173234 Himachal Pradesh India

An internal failure mode for a soil-nailed system consists of failure at nail heads,slope facing,nail strength,along groutesoil interface and pullout failure.A better understanding of pullout of soil nail thus becomes important to assess the stability of a soil-nailed *** the present study,an investigation into the pullout behaviour of soil nail with circular discs along the shaft has been carried out by a threedimensional finite element analysis using Abaqus/Explicit routine.A total of 67 simulations have been performed to accurately predict the pullout behaviour of soil *** soil nail under study has circular discs along its shaft varying in numbers from 1 to *** pullout of this soil nail in a pullout test box has been simulated with a constant overburden pressure of 20 kPa acting on the *** pullout load edisplacement characteristics,stresses around soil nail and failure mechanism during pullout are *** of dimensionless factors such as normalised pullout load factor and bearing capacity factor have been obtained with different combinations of parameters in terms of relative disc spacing ratio,anchorage length ratio,embedment ratio,diameter ratio and displacement *** the results of analyses,it is found that nail with more circular discs requires higher pullout *** are critical relative disc spacing ratio and diameter ratio which significantly affect the pullout behaviour of nail.

关键词： Pullout behaviour Finite element analysis Soil nail Circular discs Dimensionless factors

Effects of particle size and confining pressure on breakage factor of rockfill materials using medium triaxial test

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Journal of Rock Mechanics and Geotechnical Engineering 2016年第3期8卷 378-388页

作者： ashok kumar gupta Civil Engineering Department Jaypee University of Information Technology

Rockfill dams are mostly constructed using blasted rockfill materials obtained by blasting rocks or alluvial rockfill materials collected from the riverbeds. Behaviors of rockfill materials and their characterization signifcantly depend on breakage factor observed during triaxial loading. In this paper, two modeled rockfill materials are investigated by using medium triaxial cell. Drained triaxial tests are conducted on various sizes of modeled rockfill materials used in the two dams, and test data are analyzed accordingly. Breakage factor of rockfill material is studied and the effects of particle size and confining pressure on breakage factor are investigated using medium triaxial cell as many researchers have already conducted investigation using large triaxial cell.

关键词： Triaxial testsRockfill materialsParticle sizeConfining pressureBreakage factor

Impact of open dumping of municipal solid waste on soil properties in mountainous region

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Journal of Rock Mechanics and Geotechnical Engineering 2018年第4期10卷 725-739页

作者： Anchal Sharma ashok kumar gupta Rajiv Ganguly Department of Civil Engineering Jaypee University of Information Technology

This paper presents the effect of open dumping of municipal solid waste(MSW) on soil characteristics in the mountainous region of Himachal Pradesh, India. The solid waste of dumpsite contains various complex characteristics with organic fractions of the highest proportions. As leachate percolates into the soil, it migrates contaminants into the soil and affects soil stability and strength. The study includes the geotechnical investigation of dump soil characteristics and its comparison with the natural soil samples taken from outside the proximity of dumpsites. The geochemical analysis of dumpsite soil samples was also carried out by scanning electron microscopy(SEM) and energy dispersive X-ray spectroscopy(EDS).Visual inspection revealed that the MSW consists of high fraction of organics, followed by paper. The soil samples were collected from five trial pits in the dumpsites at depths of 0.5 m, 1 m and 1.5 m. Then the collected soil samples were subjected to specific gravity test, grain size analysis, Atterberg’s limit test,compaction test, direct shear test, California bearing ratio(CBR) test and permeability analysis. The study indicated that the dumpsite soils from four study regions show decreasing trends in the values of maximum dry density(MDD), specific gravity, cohesion and CBR, and increasing permeability as compared to the natural soil. The results show that the geotechnical properties of the soils at all four study locations have been severely hampered due to contamination induced by open dumping of waste.

关键词： Municipal solid waste (MSW) Physical characterization Soil pollution Open dumping Scanning electron microscopy (SEM) Energy disperse X-ray spectroscopy (EDS)

Deep learning models for tuberculosis detection and infected region visualization in chest X-ray images

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Intelligent Medicine 2024年第2期4卷 104-113页

作者： Vinayak Sharma Nillmani Sachin kumar gupta Kaushal kumar Shukla School of Electronics and Communication Engineering Shri Mata Vaishno Devi University Jammu and KashmirIndia School of Biomedical Engineering Indian Institute of TechnologyBanaras Hindu UniversityVaranasiIndia Department of Computer Science and Engineering Indian Institute of TechnologyBanaras Hindu UniversityVaranasiIndia

Objective Tuberculosis(TB)is among the most frequent causes of infectious-disease-related *** being treatable by antibiotics,tuberculosis often goes misdiagnosed and untreated,especially in rural and low-resource *** X-rays are frequently used to aid diagnosis;however,this presents additional challenges because of the possibility of abnormal radiological appearance and a lack of radiologists in areas where the infection is most *** deep-learning-based imaging techniques for computer-aided diagnosis has the potential to enable accurate diagnoses and lessen the burden on medical *** the present work,we aimed to develop deep-learning-based segmentation and classification models for accurate and precise detection of tuberculosis in chest X-ray images,with visualization of infection using gradient-weighted class activation mapping(Grad-CAM)*** First,we trained the UNet segmentation model using 704 chest X-ray radiographs taken from the Montgomery County and Shenzhen Hospital ***,we implemented the trained UNet model on 1,400 tuberculosis and control chest X-ray scans to segment the lung *** images were taken from the National Institute of Allergy and Infectious Diseases(NIAID)TB portal program ***,we applied the deep learning Xception model to classify the segmented lung region into tuberculosis and normal *** further investigated the visualization capabilities of the model using Grad-CAM to view tuberculosis abnormalities in chest X-rays and discuss them from radiological *** For segmentation by the UNet model,we achieved accuracy,Jaccard index,Dice coefficient,and area under the curve(AUC)values of 96.35%,90.38%,94.88%,and 0.99,*** classification by the Xception model,we achieved classification accuracy,precision,recall,F1-score,and AUC values of 99.29%,99.30%,99.29%,99.29%,and 0.999,*** Grad-CAM heatmap images from the tuberculos

关键词： Tuberculosis Artificial intelligence Deep learning Segmentation Classification Chest X-ray

A Novel Multi-objective Protection Coordination Scheme for a Microgrid with Optimal Deployment of Dual-setting ROCOV Based Relays

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Protection and Control of Modern Power Systems 2024年第4期9卷 23-38页

作者： Praveen kumar gupta Priyanshul Niranjan Niraj kumar Choudhary Nitin Singh Ravindra kumar Singh the Department of Electrical Engineering Motilal Nehru National Institute of Technology AllahabadPrayagraj 211004India

Relay coordination is crucial in electrical power systems to protect against malfunctions and damage caused by unexpected events like short *** address the challenge associated with the reverse direction of fault current,dual-setting(DS)directional over-current relays have evolved but failed to provide proper coordination during changes of load,generation,and *** the meantime,with the increasing number of DS relays,the total relay operating time tends to ***,this paper proposes a protection scheme based on the optimal deployment of conventional and dual-setting rate of change of voltage(DS-ROCOV)relays in distribution *** holds true for varying network topologies and is unaffected by variations in load and *** objective of the proposed scheme is to ensure reliable and efficient protection against faults in distribution systems by minimizing the overall operating time with the optimal number of DS-ROCOV *** proposed protection scheme’s performance is evaluated for different coordination time interval values as well as in different microgrid *** paper outlines the design and implementation of the proposed protection scheme which is validated on the modified IEEE 14-bus system using simulations in Matlab/Simulink.

关键词： Coordination time interval DS-ROCOV relay multi-objective optimization optimal-deployment protection coordination

Microstructural, wettability, and corrosion behaviour of TiO_(2) thin film sputtered on aluminium

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Journal of Central South University 2024年第7期31卷 2210-2224页

作者： Rajeev VERMA Vijay kumar Saurabh KANGO Amindra KHILLA Rajeev gupta Department of Industrial and Production Engineering Dr B R Ambedkar National Institute of Technology JalandharJalandhar-144008PunjabIndia Department of Mechanical Engineering Dr B R Ambedkar National Institute of Technology JalandharJalandhar-144008PunjabIndia Department of Physics School of EngineeringUniversity of Petroleum&Energy StudiesDehradun 248007UttarakhandIndia

The study investigated the application of radiofrequency(RF)-sputtered TiO2 coatings at various temperatures to enhance the hydrophobicity and corrosion resistance of Al6061 *** research aimed to establish a correlation between the coating process and the resulting surface *** roughness and wettability were quantified with a surface profilometer and ***,chemical boiling and salt spray corrosion tests were conducted to evaluate any topographical changes during these *** analysis further involved the use of field-emission scanning electron microscopy(FESEM),energy-dispersive spectroscopy(EDS),and X-ray diffraction(XRD)techniques to characterize the deposited *** findings indicated that the TiO2 coating applied at 500℃exhibited the highest water contact angle and superior corrosion resistance compared to other *** characterization confirmed that this specific TiO_(2) coating at 500℃ effectively delays corrosion due to its hydrophobic behavior,making it durable for industrial applications.

关键词： aluminium TiO_(2)coating radiofrequency-sputtering hydrophobic corrosion

Gallbladder cancer:Progress in the Indian subcontinent

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World Journal of Clinical Oncology 2024年第6期15卷 695-716页

作者： ashok kumar Yajnadatta Sarangi Annapurna gupta Aarti Sharma Department of Surgical Gastroenterology Sanjay Gandhi Post Graduate Institute of Medical SciencesLucknow 226014Uttar PradeshIndia Division of Haematology Mayo Clinic ArizonaPhoenixAZ 85054United States

Gallbladder cancer(GBC)is one of the commonest biliary malignancies seen in India,Argentina,and *** disease has dismal outcome as it is detected quite late due to nonspecific symptoms and *** detection is the only way to improve the *** have been several advances in basic as well as clinical research in the hepatobiliary and pancreatic diseases in the West and other developed countries but not enough has been done in ***,it is imp-ortant and the responsibility of the countries with high burden of GBC to find solutions to the many unanswered questions like etiopathogenesis,early diagn-osis,treatment,and *** India being one of the largest hubs for GBC in the world,it is important to know how the country has progressed on *** this review,we will discuss the outcome of the publications from India highlighting the work and the developments taken place in past several decades both in basic and clinical research.

关键词： Gallbladder cancer India basic research Clinical research Surgery Therapeutics

Autologous peripheral blood-derived orthobiologics:Different types and their effectiveness in managing knee osteoarthritis

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World Journal of Orthopedics 2024年第5期15卷 400-403页

作者： Ashim gupta Vijay kumar Jain Department of Orthopaedics and Regenerative Medicine Future BiologicsLawrencevilleGA 30043United States Department of Orthopaedics South Texas Orthopaedic Research Institute(STORI Inc.)LaredoTX 78045United States Department of Regenerative Medicine BioIntegrateLawrencevilleGA 30043United States Department of Orthopaedics and Regenerative Medicine Regenerative OrthopaedicsNoida 201301India Department of Orthopaedics Atal Bihari Vajpayee Institute of Medical SciencesDr.Ram Manohar Lohia HospitalDelhi 110001New DelhiIndia

Knees are the most commonly impacted weight-bearing joints in osteoarthritis(OA),affecting millions of people *** increasing life spans and obesity rates,the incidence of knee OA will further increase,leading to a significant increase in the economic *** treatment modalities utilized to manage knee OA have *** the last decade,the role of various autologous peripheral blood-derived orthobiologics(APBOs)for the treatment of knee OA has been extensively *** editorial provided an overview and focused on defining and shedding light on the current state of evidence based on the most recent published clinical studies concerning the use of APBO for the management of knee *** numerous studies have demonstrated promising results for these preparations,a notable gap exists in the comparative analysis of these diverse *** absence of head-to-head studies poses a considerable challenge for physicians/surgeons in determining the optimal preparation for managing knee OA and achieving sustained longterm ***,more adequately powered,multicenter,prospective,doubleblind,randomized controlled trials with longer follow-ups are needed to establish the long-term efficacy and to aid physicians/surgeons in determining the optimal APBO for the management of knee OA.

关键词： Knee osteoarthritis Platelet-rich plasma Platelet lysate Autologous conditioned serum Gold-induced cytokine Plasma rich in growth factors Growth factor concentrate Autologous protein solution Platelet-rich fibrin Hyperacute serum