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Chinese Physics B 2016年第5期25卷 429-433页

作者： A kumaresh r arun kumar N ravikumar U Madhusoodanan B S Panigrahi K Marimuthu M Anuradha GrD Centre for Materials research PSG College of TechnologyCoimbatoreIndia Department of Physics PSG College of TechnologyCoimbatoreIndia radiation Safety Division Indira Gandhi Centre for Atomic ResearchKalpakkamIndia Department of Physics Gandhigram Rural UniversityDindigulIndia PSG Institute of Advanced Studies CoimbatoreIndia

rare earth europium（Eu（3＋））-doped lithium tetraborate（Eu：Li_2B_4O_7） crystal is grown from its stoichiometric melt by microtube Czochralski pulling technique（μT-Cz） for the first time. The grown crystals are subjected to powder x-ray diffraction（PXrD） analysis which reveals the tetragonal crystal structure of the crystals. UV–vis–NIr spectral analysis is carried out to study the optical characteristics of the grown crystals. The crystal is transparent in the entire visible region, and the lower cutoff is observed to be at 304 nm. The existence of BO_3 and BO_4 bonding structure and the molecular associations are analyzed by Fourier transform infrared（FTIr） spectroscopy. The results of excitation and emission-photoluminescence spectra of europium ion incorporated in lithium tetraborate（LTB） single crystal reveal that the observations of peaks at 258,297, and 318 nm in the excitation spectra and peaks at 579, 591, 597, 613, and 651 nm are observed in the emission *** chromaticity coordinates are calculated from the emission spectra, and the emission intensity of the grown crystal is characterized through a CIE 1931（Commission International d＇Eclairage） color chromaticity diagram.

关键词： crystal growth optical material growth from melt photoluminescence study

Endothelial dysfunction in the kidney transplant population:Current evidence and management strategies

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World Journal of Transplantation 2025年第1期15卷 24-43页

作者： arun Prabhahar Akshey Batta Juniali Hatwal Vivek kumar raja ramachandran Akash Batta Department of Telemedicine(Internal Medicine and Nephrology) Post Graduate Institute of Medical Education and ResearchChandigarh 160012India Department of Urology and renal Transplant Neelam HospitalRajpura 140401PunjabIndia Department of Internal Medicine Post Graduate Institute of Medical Education and ResearchChandigarh 160012India Department of Nephrology Post Graduate Institute of Medical Education and ResearchChandigarh 160012India Department of Cardiology Dayanand Medical College and HospitalLudhiana 141001PunjabIndia

The endothelium modulates vascular homeostasis owing to a variety of vasoconstrictors and *** dysfunction(ED),characterized by impaired vasodilation,inflammation,and thrombosis,triggers future cardiovascular(CV)*** kidney disease,a state of chronic inflammation caused by oxidative stress,metabolic abnormalities,infection,and uremic toxins damages the *** is also associated with a decline in estimated glomerular filtration *** kidney transplantation,endothelial functions undergo immediate but partial restoration,promising graft longevity and enhanced CV ***,the anticipated CV outcomes do not happen due to various transplant-related and unrelated risk factors for ED,culminating in poor CV health and graft *** in kidney transplant recipients is an underrecognized and poorly studied *** diseases are the leading cause of death among kidney transplant candidates with functioning *** contributes to the pathogenesis of many of the CV *** biomarkers and vasoreactivity tests are available to study endothelial *** an increasing number of transplants happening every year,and improved graft rejection rates due to the availability of effective immunosuppressants,the focus has now shifted to endothelial protection for the prevention,early recognition,and treatment of CV diseases.

关键词： Endothelial dysfunction Endothelium Cardiovascular disease Kidney transplantation Chronic kidney disease Nitric oxide Flow-mediated dilatation Nitro-glycerine-mediated dilatation Biomarkers

Shock wave mitigation using zig-zag structures and cylindrical obstructions

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Defence Technology（防务技术） 2021年第6期17卷 1840-1851页

作者： arun kumar r Vaibhav Pathak Department of Mechanical Engineering Indian Institute of Technology Jodhpur(IITJ)JodhpurRajasthan342037India

The present study focuses on the mitigation of shock wave using novel geometric passages in the flow *** strategy is to produce multiple shock reflections and diffractions in the passage with minimum flow obstruction,which in turn is expected to reduce the shock wave strength at the target *** the present study the interaction of a plane shock front(generated from a shock tube)with various geometric designs such as,1)zig-zag geometric passage,2)staggered cylindrical obstructions and 3)zigzag passage with cylindrical obstructions have been investigated using computational *** is seen from the numerical simulation that,among the various designs,the maximum shock attenuation is produced by the zig-zag passage with cylindrical obstructions which is then followed by zig-zag passage and staggered cylindrical obstructions.A comprehensive investigation on the shock wave reflection and diffraction phenomena happening in the proposed complex passages have also been carried *** the new zig-zag design,the initial shock wave undergoes shock wave reflection and diffraction process which swaps alternatively as the shock front moves from one turn to the other *** cyclic shock reflection and diffraction process helps in diffusing the shock wave energy with practically no obstruction to the flow *** is found that by combining the shock attenuation ability of zig-zag passage(using shock reflection and diffraction)with the shock attenuation ability of cylindrical blocks(by flow obstruction),a drastic attenuation in shock strength can be achieved with moderate level of flow blocking.

关键词： Blast wave mitigation Blockage ratio Geometric obstructions Shock wave reflection and diffraction Zig-zag structure

Evolution of the 2015/16 El Nio and historical perspective since 1979

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Science China Earth Sciences 2017年第9期60卷 1572-1588页

作者： Yan XUE arun kumar Climate Prediction Center National Centers for Environmental Prediction National Weather Service National Oceanic and Atmospheric Administration College Park MD 20740 USA

The 2015/16 El Nio developed from weak warm conditions in late 2014 and NINO3.4 reached 3℃ in November 2015. We describe the characteristics of the evolution of the 2015/16 El Nio using various data sets including SST, surface winds,outgoing longwave radiation and subsurface temperature from an ensemble operational ocean reanalyses, and place this event in the context of historical ENSO events since 1979. One salient feature about the 2015/16 El Nio was a large number of westerly wind bursts and downwelling oceanic Kelvin waves(DWKVs). Four DWKVs were observed in April-November 2015 that initiated and enhanced the eastern-central Pacific warming. Eastward zonal current anomalies associated with DWKVs advected the warm pool water eastward in spring/summer. An upwelling Kelvin wave(UWKV) emerged in early November 2015 leading to a rapid decline of the event. Another outstanding feature was that NINO4 reached a historical high(1.7℃), which was 1℃(0.8℃) higher than that of the 1982/83(1997/98) El Nio . Although NINO3 was comparable to that of the 1982/83 and 1997/98 El Nio , NINO1+2 was much weaker. Consistently, enhanced convection was displaced 20 degree westward, and the maximum D20 anomaly was about 1/3.1/2 of that in 1997 and 1982 near the west coast of South America.

关键词： ENSO Sea surface temperature Westerly wind bursts Ocean Kelvin waves Thermocline variability Ocean reanalysis

Comparative cytotoxicity of nanoparticles and ions to Escherichia coli in binary mixtures

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Journal of Environmental Sciences 2017年第5期29卷 11-19页

作者： Swati Srivastaua arun kumar Department of Civil Engineering Indian Institute of Technology Delhi New Delhi 110016 India

The objective of this study was to understand toxicity of mixture of nanoparticles （NPs）（ZnO and TiO2） and their ions to Escherichia coll. results indicated the decrease in percentage growth of E. coli with the increase in concentration of NPs both in single and mixture setups. Even a small concentration of I mg/L was observed to be significantly toxic to E. coli in binary mixture setup （exposure concentration： 1 mg/L ZnO and 1 mg/L TiO2; 21.15% decrease in plate count concentration with respect to control）. Exposure ofE. coli to mixture of NPs at 1000 mg/L （i.e., 1000 mg/L ZnO and 1000 mg/L TiO2） resulted in 99.63% decrease in plate count concentration with respect to control. Toxic effects of ions to E. coli were found to be lesser than their corresponding NPs. The percentage growth reduction was found to be 36% for binary mixture of zinc and titanium ions at the highest concentration （i.e., 803.0 mg/L Zn and 593.3 mg/L Ti where ion concentrations are equal to the Zn ions present in 1000 mg/L ZnO NP solution and Ti＋4 ions present in 1000 mg/L TiO2 NP solution）. Nature of mixture toxicity of the two NPs to E. coli was found to be antagonistic. The alkaline phosphatase （Alp） assay indicated that the maximum damage was observed when E. coli was exposed to 1000 mg/L of mixture of NPs. This study tries to fill the knowledge gap on information of toxicity of mixture of NPs to bacteria which has not been reported earlier.

关键词： E. coli Zinc oxide nanoparticles Titanium dioxide nanoparticles Mixture toxicity Alkaline phosphatase assay

PAPr reduction in NOMA by Using Hybrid Algorithms

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Computers, Materials & Continua 2021年第10期69卷 1391-1406页

作者： Mohit kumar Sharma arun kumar Department of Electronics and Communication Engineering JECRC UniversityJaipur303905India

Non-orthogonal multiple access(NOMA)is gaining considerable attention due to its features,such as low out-of-band radiation,signal detection capability,high spectrum gain,fast data rate,and massive D2D *** may be considered for 5G ***,the high peak-to-average power ratio(PAPr)is viewed as a significant disadvantage of a NOMA waveform,and it weakens the quality of signals and the throughput of the *** this article,we introduce a modified NOMA system by employing a block of wavelet transform,an alternative to FFT(Fast Fourier transform).The modified system combines the details of fractional frequency and time analysis of NOMA *** this correspondence,we utilize an advanced partial transmission scheme(PTS),and selective mapping(SLM),and present a genetic algorithm(GA)for SLM to investigate the peak power performance of a WT-based NOMA *** performance of WT-SLM,WT-PTS,and WT-SLM-GA methods is compared with that of the traditional NOMAbased SLM and PTS *** simulation results demonstrate that the proposed system effectively reduces PAPr in comparison with the traditional schemes.

关键词： PAPr wavelet transform NOMA PTS SLM 5G

MATHEMATICAL DESCrIPTION OF GrOWTH OF MULTIPLE rOOT BrANCHING STrUCTUrE IN A PLANT

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International Journal of Biomathematics 2013年第3期6卷 1-10页

作者： arun kumar Department of Mathematics Government College Kota (Raj.) India

An existing growth model of Edelstien is extended and modified for multiple root branching structure or root hairs of any plant. Numerical and analytical solutions for the model are developed and compared. In the derivation it is assumed that multiple root branches are attached to the root surface that acts as a continuous source of new tips. The numerical scheme is derived with anticipation of the fact that comparison with experimental data may necessitate a more complicated model.

关键词： Uptake parameter asymptotic matching van Genuchten formula relativewater content.

Effect of simvastatin on paraoxonase 1(PON1) activity and oxidative stress

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Asian Pacific Journal of Tropical Medicine 2010年第4期3卷 310-314页

作者： arun kumar Department of Biochemistry College of MedicineThe West Bengal University of Health SciencesKalyaniNadia Pin:741235

Objective:To investigate the effect of simvastatin treatment on lipid pr of ile and oxidative stress in hypercholesterolaemic Indian population and determine the effect of simvastatin treatment on the activity of paraoxonase（PON）.Methods:Analyzed initially before medication administration and four months later after *** and lipoprotein measurement were done by enzymatic kits,high density lipoprotein（HDL） was determined by phosphotungstic acid precipitation method and low density lipoprotein（LDL） was calculated by Friedewald’s *** peroxidation was measured by three markers namely,conjugated diene,total peroxide,and *** diene was assayed by Buege and Aust *** peroxide was determined by FOX2 *** determination was carried out by Flemming method and total antioxidant status was determined by *** activity was determined by measuring the absorbance inrease of p-nitrophenol at 405 *** activity was calculated from the molar coefficient of 1 310 M-1 cm-1.results:Simvastatin significantly reduced total cholesterol,triglycerides,LDL,conjugated diene,total peroxide and MDA levels,where as antioxidant status was significantly ***,simvastatin significantly increased PON1 activity towards ***:The results from the current study indicate simvastatin may have important antioxidant properties via increasing PON activity.

关键词： Hypercholesterolaemia Simvastatin Oxidative stress India

A Parallel Interval Computation Model for Global Optimization with Automatic Load Balancing

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Journal of Computer Science & Technology 2012年第4期27卷 744-753页

作者：吴勇 arun kumar Department of International Business and Asian Studies Griffith University School of Aerospace Mechanical and Manufacturing EngineeringRMIT University

In this paper, we propose a decentralized parallel computation model for global optimization using interval analysis. The model is adaptive to any number of processors and the workload is automatically and evenly distributed among all processors by alternative message passing. The problems received by each processor are processed based on their local dominance properties, which avoids unnecessary interval evaluations. Further, the problem is treated as a whole at the beginning of computation so that no initial decomposition scheme is required. Numerical experiments indicate that the model works well and is stable with different number of parallel processors, distributes the load evenly among the processors, and provides an impressive speedup, especially when the problem is time-consuming to solve.

关键词： parallel processing automatic load balancing computation model interval analysis global optimization

Determination of the particle load based on detailed suspended sediment measurements at a hydropower plant

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International Journal of Sediment research 2019年第5期34卷 409-421页

作者： Anant kumar rai arun kumar Alternate Hydro Energy Centre

Suspended sediment particles contained in inflows of water systems of hydropower plants(HPPs) cause hydro-abrasive erosion of the hydraulic turbines and structures leading to significant maintenance costs,efficiency reductions, and downtime. relevant parameters such as suspended sediment concentration(SSC), particle size distribution(PSD), shape, and mineralogical composition were measured with an online multi-frequency acoustic instrument and based on manually taken samples from the end of the sand trap of the Toss HPP in the Himalayan region, India. In the laboratory, the samples were analyzed using the gravimetric method, laser diffraction, turbidity, dynamic digital image processing, scanning electron microscope, petrography analysis, energy-dispersive X-ray spectroscopy, and X-ray *** online instrument and the samples provided measurement results at a single point. To investigate vertical gradients in concentration and particle sizes, additional samples were collected 9 times at 7 relative water depths. The SSC, most particle sizes, and particle shape were found to be evenly distributed over depth except d90, i.e. the diameter which is not exceeded by 90% of the particle mass. d90 measured at 76% of the water depth was in the range of fine sand and was multiplied by 1.05 to obtain an average value representative for the entire depth. Improved methodologies to quantify both particle shape and size in an analytical model for hydro-abrasive erosion are proposed. Also, the PSD measuring performance of laser diffraction and dynamic imaging was studied and similar values of the median particle sizes were obtained from both instruments. Further, multi-frequency acoustic, turbidity and laser diffraction techniques were found suitable for SSC measurement at the test case HPP.

关键词： Suspended sediment concentration Hydro-abrasive erosion Hydropower Particle size distribution Particle shape Mineralogical composition