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Drag reduction by application of aerodynamic devices in a race car

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Advances in Aerodynamics 2021年第1期3卷 66-85页

作者： Devang S.Nath Prashant Chandra Pujari amit jain Vikas Rastogi Department of Mechanical Engineering Delhi Technological UniversityDelhi 110042India

In this era of fast-depleting natural resources,the hike in fuel prices is *** stringent norms over environmental policies,the automotive manufacturers are on a voyage to produce efficient vehicles with lower ***-speed cars are at a stake to provide uncompromised performance but having strict rules over emissions drives the companies to approach through a different route to keep the demands of performance *** of the most sought-after ways is to improve the aerodynamics of the *** force is one of the major setbacks when it comes to achieving high speeds when the vehicle is in *** research aims to examine the effects of different add on devices on the vehicle to reduce drag and make the vehicle aerodynamically streamlined.A more streamlined vehicle will be able to achieve high speeds and consequently,the fuel economy is also *** three-dimensional car model is developed in SOLIDWORKS *** Fluid Dynamics(CFD)is performed to understand the effects of these add on *** is carried out in the ANSYS^(TM) 17.0 Fluent *** Coefficient(CD),Lift Coefficient(CL),Drag Force and Lift Force are calculated and compared in different *** result of the simulations was analyzed and it was observed that different devices posed several different functionalities,but maximum drag reduction was found in the case of GT with spoiler and diffuser with a maximum reduction of 16.53%.

关键词： Aerodynamics CFD Drag force Drag coefficient High speed car

Design and development of a plastic scintillator based whole body β/γ contamination monitoring system

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Nuclear Science and Techniques 2021年第5期32卷 33-42页

作者： Vaishali M.Thakur amit jain P.Ashokkumar Rekha Anilkumar Pravin Sawant Probal Chaudhury L.M.Chaudhari Radiation Safety Systems Division Bhabha Atomic Research CentreMumbai 400085India Health Physics Division Bhabha Atomic Research CentreMumbai 400085India Department of Physics Nowrosjee Wadia CollegePuneMaharashtra 411001India

Plastic scintillation detectors based whole body β/γ contamination monitors are developed for use in radiation *** microcontroller-based multi-detector system uses 13 plastic scintillator detectors,with minimized dead detection zones,monitoring the whole body,and conforming to the contamination limit prescribed by the regulatory *** system has the features for monitoring hands,feet,head,and faceβ/γusing contamination monitors and portal exit *** can detect gamma sources at a dose rate of 10 n Gyh^(-1).The system is calibrated using b sources^(90)Sr/^(90)Y,^(204)Tl,and^(36)Cl,and the efficiency is found to be 29%,22%,and 18%,***β/γcontaminationis0.15 Bqcm^(-2),which is significantly less than the minimum detection objectives on head,face,hands,and feet.

关键词： Plastic scintillation detector Contamination monitor Microcontroller Minimum Detection Objective(MDO) Minimum Detection Concentration(MDC)

Gastric conduit perforation

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World Journal of Clinical Cases 2014年第8期2卷 398-401页

作者： Nilesh Patil Arvind Kaushal amit jain Sundeep Singh Saluja Pramod Kumar Mishra Department of Gastrointestinal Surgery Academic BlockGB Pant Hospital and Maulana Azad Medical CollegeNew Delhi 110002India

As patients with carcinoma of the esophagus live longer, complications associated with the use of a gastric conduit are increasing. Ulcers form in the gastric conduit in 6.6% to 19.4% of patients. There are a few reports of perforation of a gastric conduit in the English literature. Almost all of these were associated with serious complications. We report a patient who developed a tension pneumothorax consequent to spontaneous perforation of an ulcer in the gastric conduit 7 years after the index surgery in a patient with carcinoma of the gastroesophageal junction. He responded well to conservative management. Complications related to a gastric conduit can be because of multiple factors. Periodic endoscopic surveillance of gastric conduits should be considered as these are at a higher risk of ulcer formation than a normal stomach. Long term treatment with proton pump inhibitors may decrease complications. There are no guidelines for the treatment of a perforated gastric conduit ulcer and the management should be individualized.

关键词： Gastric conduit Ulcer formation Perforation Carcinoma of the esophagus Proton pump inhibitors

Plastic scintillator detector for qualitative and quantitative measurements of gamma radiation

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Radiation Detection Technology and Methods 2023年第4期7卷 578-588页

作者： Vaishali M.Thakur Nitin Bhosale amit jain Mukesh Sharma L.M.Chaudhari Probal Chaudhury Radiation Safety Systems Division Bhabha Atomic Research CentreTrombayMumbai400085India Department of Physics Nowrosjee Wadia CollegePune411001India

Background Plastic scintillator detectors are rugged and easily manufactured in desired shape,sizes and response time to gamma radiation is prompt as compared with any other scintillator *** popular these detectors are used in radiation monitors one of the application to restrict radioactive material *** are used in gross counting mode to know the presence of *** secondary survey is required to know the nature of the *** The feasibility study of Cylindrical Plastic Scintillator Detector(CPSD)was carried out for the qualitative and quantitative assessment of gamma emitting *** In this work limited gamma spectrometry was carried out using NE110 equivalent cylindrical plastic scintillating material of 5.1 cm diameter and 100 cm *** is optically coupled to photomultiplier tube(PMT).The detector signal is processed using preamplifier,shaping amplifier and further analysed by a multi channel analyser(MCA).CPSD gamma spectrum consists of Compton continuum and Gaussian shaped Compton edge energy(λ_(e))appearing as Compton maxima energy(λ_(max)).Photon transport simulation is used to characterizeλ_(max) as a signature for radionuclides emitting gamma energy/*** case of unresolved gamma energies,it appears as weighted effective Compton maxima *** prominent gamma energies observed across nuclear industries are in the energy range 0.03–3 *** is grouped as low energy,intermediate energy,high energy and ultra-high energy *** simulated spectrum is obtained suing Gaussian broadening parameters deduced from experimentally measured *** efficiency response function is developed from simulated response of detector to standard gamma sources under known source detector *** The mono energetic gamma emitting radioisotopes are identified againstλ_(max) from data *** analysis of spectrum is used to discriminate artificial radioactive materi

关键词： Plastic scintillator detector Gaussian broadening Compton edge Compton maxima Weighted effective Compton maxima Gamma spectrum Multi-channel analyzer

Demand Elasticity of Capacity Offered for Urban Rail Transport

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Journal of Transportation Technologies 2016年第4期6卷 163-168页

作者： Pradeep Kumar Sarkar jain amit Kumar Transport Planning School of Planning & Architecture New Delhi India Traffic Department Northern Railways New Delhi India

The high peak hour demand in Urban Rail Transport (URT) is usually met by supply side measures such as pushing more number of trains/cars in peak hour by the operator. This additional capacity generates more demand due to a positive elasticity of demand with respect to services. Delhi Metro Rail Corporation (DMRC), India has converted its fleet from 4 cars per train to 6 cars per train and finally to 8 cars per train on its Broad Gauge section. The ridership of the system has also witnessed double digit growth during this conversion period. The demand elasticity w.r.t services for the passengers of DMRC has been estimated as 0.512 on the basis of growth of demand and increase in capacity after adjusting for natural growth. So a 10% increase in supply results into 5% increase in capacity. A simple service elasticity model has been developed to estimate demand with increase in supply. The model has been applied to Line 2 (yellow line), the busiest line of DMRC, to estimate the demand for different level of services (trains/hour). The efficacy of supply side measures is limited by the design capacity of the system beyond which any increase in supply would require disproportionate investment. An optimum combination of supply and demand side measures would perhaps be the best way to address peak hour congestion in Urban Rail Transport.

关键词： Congestion Demand Elasticity Supply Urban Rail Transport

Mechanosignaling activation of TGFβmaintains intervertebral disc homeostasis

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Bone Research 2017年第1期5卷 27-40页

作者： Qin Bian Lei Ma amit jain Janet L Crane Khaled Kebaish Mei Wan Zhengdong Zhang X Edward Guo Paul D Sponseller Cheryle A Seguin Lee H Riley Yongjun Wang Xu Cao Department of Orthopaedic Surgery Institute for Cell EngineeringJohns Hopkins UniversityBaltimoreMDUSA Institute of Spine Longhua HospitalShanghai University of Traditional Chinese MedicineShanghaiPR China Department of Pediatrics Johns Hopkins UniversityBaltimoreMDUSA Department of Biomedical Engineering Columbia UniversityNYUSA Departments of Physiology and Pharmacology University of Western OntarioLondonCanada

Intervertebral disc （IVD） degeneration is the leading cause of disability with no disease-modifying treatment. IVD degeneration is associated with instable mechanical loading in the spine, but little is known about how mechanical stress regulates nucleus notochordal （NC） cells to maintain IVD homeostasis. Here we report that mechanical stress can result in excessive integrin αvβ6-mediated activation of transforming growth factor beta （TGFβ）, decreased NC cell vacuoles, and increased matrix proteoglycan production, and results in degenerative disc disease （DDD）. Knockout of TGFβ type II receptor （TβRII） or integrin αv in the NC cells inhibited functional activity of postnatal NC cells and also resulted in DDD under mechanical loading. Administration of RGD peptide, TGFβ, and αvβ6-neutralizing antibodies attenuated IVD degeneration. Thus, integrin-mediated activation of TGFβ plays a critical role in mechanical signaling transduction to regulate IVD cell function and homeostasis. Manipulation of this signaling pathway may be a potential therapeutic target to modify DDD.

关键词： Mechanosignaling activation of TGF maintains intervertebral disc homeostasis IVD

Ciliary parathyroid hormone signaling activates transforming growth factor-βto maintain intervertebral disc homeostasis during aging

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Bone Research 2018年第3期6卷 252-265页

作者： Liwei Zheng Yong Cao Shuangfei Ni Huabin Qi Zemin Ling Xin Xu Xuenong Zou Tianding Wu Ruoxian Deng Bo Hu Bo Gao Hao Chen Yusheng Li Jianxi Zhu Francis Tintani Shadpour Demehri amit jain Khaled M.Kebaish Shenghui Liao Cheryle A.Séguin Janet L.Crane Mei Wan Hongbin Lu Paul D.Sponseller Lee H.RileyIII Xuedong Zhou Jianzhong Hu Xu Cao Department of Orthopedic Surgery Johns Hopkins University School of MedicineRoss BuildingRoom 229720 Rutland AveBaltimoreMDUSA State Key Laboratory of Oral Diseases West China Hospital of StomatologySichuan UniversityChengduChina Department of Spine Surgery Xiangya HospitalCentral South UniversityChangshaChina Center of Bone Metabolism and Repair(CBMR) Trauma CenterInstitute of Surgery ResearchDaping HospitalThird Military Medical UniversityChongqingChina Guangdong Provincial Key Laboratory of Orthopedics and Traumatology Department of Spinal SurgeryThe First Affiliated Hospital of Sun Yat-sen UniversityGuangzhouChina Department of Pediatrics Johns Hopkins University School of MedicineRoss BuildingRoom 229720 Rutland AveBaltimoreMDUSA The Russell H.Morgan Department of Radiology and Radiological Science Johns Hopkins University School of MedicineRoss BuildingRoom 229720 Rutland AveBaltimoreMDUSA Faculty of Computer Science College of Information Science and EngineeringXiangya HospitalCentral South UniversityChangshaChina Department of Physiology and Pharmacology Schulich School of Medicine and DentistryUniversity of Western OntarioLondonONCanada Department of Sports Medicine Xiangya HospitalCentral South UniversityChangshaChina

Degenerative disc disease(DDD) is associated with intervertebral disc degeneration of spinal instability. Here, we report that the cilia of nucleus pulposus(NP) cells mediate mechanotransduction to maintain anabolic activity in the discs. We found that mechanical stress promotes transport of parathyroid hormone 1 receptor(PTH1 R) to the cilia and enhances parathyroid hormone(PTH) signaling in NP cells. PTH induces transcription of integrin α_vβ_6 to activate the transforming growth factor(TGF)-β-connective tissue growth factor(CCN2)-matrix proteins signaling cascade. Intermittent injection of PTH(iPTH) effectively attenuates disc degeneration of aged mice by direct signaling through NP cells, specifically improving intervertebral disc height and volume by increasing levels of TGF-β activity, CCN2, and aggrecan. PTH1 R is expressed in both mouse and human NP cells. Importantly,knockout PTH1 R or cilia in the NP cells results in significant disc degeneration and blunts the effect of PTH on attenuation of aged discs. Thus, mechanical stress-induced transport of PTH1 R to the cilia enhances PTH signaling, which helps maintain intervertebral disc homeostasis, particularly during aging, indicating therapeutic potential of iPTH for DDD.

关键词： disc injection integrin cells iPTH effect TGF-β human

Exploring the role of N-acetyltransferases in diseases:a focus on N-acetyltransferase 9 in neurodegeneration

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Neural Regeneration Research 2025年第10期20卷 2862-2871页

作者： Prajakta Deshpande Anuradha Venkatakrishnan Chimata amit Singh Department of Biology University of DaytonDaytonOHUSA Premedical Program University of DaytonDaytonOHUSA Center for Tissue Regeneration and Engineering at Dayton(TREND) University of DaytonDaytonOHUSA Integrative Science and Engineering Center University of DaytonDaytonOHUSA Center for Genomic Advocacy(TCGA) Indiana State UniversityTerre HauteINUSA

Acetyltransferases,required to transfer an acetyl group on protein are highly conserved proteins that play a crucial role in development and *** acetylation is a common post-translational modification pivotal to basic cellular *** to 80%-90%of proteins are acetylated during translation,which is an irreversible process that affects protein structure,function,life,and *** this review,we have discussed the various N-acetyltransferases present in humans,their function,and how they might play a role in ***,we have focused on N-acetyltransferase 9 and its role in microtubule *** have shed light on how N-acetyltransferase 9 and acetylation of proteins can potentially play a role in neurodegenerative *** have specifically discussed the N-acetyltransferase 9-acetylation independent function and regulation of c-Jun N-terminal kinase signaling and microtubule stability during development and neurodegeneration.

关键词： acetyl-coenzyme A Alzheimer’s disease animal models cell death drosophila eye human disease c-Jun N-terminal kinase signaling N-Acetyltransferases N-acetyltransferase 9 neurodegeneration

Exciton fine structure in twisted transition metal dichalcogenide heterostructures

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npj Computational Materials 2023年第1期9卷 417-423页

作者： Sudipta Kundu Tomer amit H.R.Krishnamurthy Manish jain Sivan Refaely-Abramson Centre for Condensed Matter Theory Department of PhysicsIndian Institute of ScienceBangalore 560012India Department of Molecular Chemistry and Materials Science Weizmann Institute of ScienceRehovot 7610001Israel Present address:Department of Materials Science and Engineering Stanford UniversityStanfordCA 94305USA

Moirésuperlattices of transition metal dichalcogenide(TMD)heterostructures give rise to rich excitonic phenomena associated with the interlayer twist *** calculations of excitons in such systems are typically based on model moirépotentials that mitigate the computational ***,predictive understanding of the electron-hole coupling dominating the excitations is crucial to realize the twist-induced modifications of the optical selection *** this work,we use many-body perturbation theory to evaluate the relation between twist angle and exciton properties in TMD *** present an approach for unfolding excitonic states from the moiréBrillouin zone onto the separate-layer *** this method to a large-angle twisted MoS^(2)/MoSe^(2) bilayer,we find that the optical spectrum is dominated by mixed electron–hole transitions with different momenta in the separate monolayers,leading to unexpected hybridization between interlayer and intralayer *** findings offer a design pathway for exciton layer-localization in TMD heterostructures.

关键词： twisted twist transition