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Complete oxidation of 1,4-dioxane over zeolite-13X-supported Fe catalysts in the presence of air

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Chinese Journal of Catalysis 2016年第2期37卷 240-249页

作者： C.ramakrishna r.krishna T.Gopi G.Swetha Bijendra Saini S.Chandra Shekar Anchal Srivastava 国防研发局、防化装备评估设备(CDEF) 印度那格浦尔MH-441108

Zeolite-13X-supported Fe（Fe/zeolite-13X） catalysts with various Fe contents were prepared by the wet impregnation *** catalysts were characterized by N2 adsorption-desorption isotherms to estimate the Brunauer-Emmett-Teller surface areas and Barrett-Joyner-Hanlenda pore size distributions.X-ray diffraction,scanning electron microscopy,temperature-programmed reduction,and temperature-programmed desorption of NH3 were used to investigate the textural properties of the Fe/zeolite-13 X *** catalytic activities were determined for the complete oxidation of1,4-dioxane using air as the oxidant in a fixed-bed flow reactor in the temperature range 100-400℃.The influences of various process parameters,such as reaction temperature,metal loading,and gas hourly space velocity（GHSV）,on the dioxane removal efficiency by catalytic oxidation were *** stability of the catalyst was tested at 400℃ by performing time-on-stream analysis for 50 *** Fe/zeolite-13 X catalyst with 6 wt%Fe exhibited the best catalytic activity among the Fe/zeolite-13 X catalysts at 400℃ and a GHSV of 24000 h^（-1）,with 97%dioxane conversion and95%selectivity for the formation of carbon oxides（CO and CO2）.Trace amounts（ 3%） of acetaldehyde,ethylene glycol monoformate,ethylene glycol diformate,1,4-dioxane-2-ol,1,4-dioxane-2-one,and 2-methoxy-1,3-dioxalane were also formed as degradation products.A plausible degradation mechanism is proposed based on the products identified by GC-MS analysis.

关键词： Iron Zeolite-13X 1 4-Dioxane Catalytic degradation Complete oxidation Degradation mechanism

Inundation Studies Along the East Coast of India due to Tsunamigenic Earthquakes in North-Andaman and Car Nicobar Subduction zone

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地学前缘 2009年第S1期16卷 65-65页

作者： r.krishna Kumar Kirti Srivastava V.Swaroopa rani V.P.Dimri National Geophysical research Institute(NGrI)(Council of Scientific and Industrial research)

The Sumatra-Andaman arc is an active subduction zone and had generated several destructive Tsunamis in the *** this paper we have analyzed two historical Tsunamigenic earthquakes from this region. One of the historical earthquake is the earthquake of 26th June 1941 in the North Andaman region,which was one of the strongest in the Andaman Sea and Bay of Bengal of magnitude M_w=*** earthquake had triggered tsunami which affected the east coast of *** other is the earthquake in Car Nicobar region on 31 st December 1881 of magnitude M_w=7.9. This submarine earthquake beneath the

关键词： inundation tsunamigenic earthquakes tsunami wave propagation run-ups

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晶体管线性延迟线路

电子计算机动态 1965年第10期 22-25页

作者： B.Nag r.krishna 伊林

这里讨论了一种晶体管延迟线路。线路的工作原理是用一单稳多谐振荡器的时基电容通过一恒流器件放电。这个恒流器件是一个工作在共基型的晶体管。线路产生一矩形脉冲,它的宽度在很大范围内正比于一直流控制电压。它还产生具有良好线性... 详细信息

这里讨论了一种晶体管延迟线路。线路的工作原理是用一单稳多谐振荡器的时基电容通过一恒流器件放电。这个恒流器件是一个工作在共基型的晶体管。线路产生一矩形脉冲,它的宽度在很大范围内正比于一直流控制电压。它还产生具有良好线性度的线性扫描电压。可得到的脉冲宽度范围很大。线性扫描的速度在一定范围内连续可变。

关键词：晶体管化电容时基基极电流脉冲宽度脉冲特性

Comparative efficacy of hyperbaric bupivacaine vs hyperbaric ropivacaine in spinal anesthesia for cesarean section:A metaanalysis

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World Journal of Methodology 2025年第2期15卷 154-165页

作者： rishi Anand Deb Sanjay Nag roushan Patel Prashant Sharma Vamsi krishna Uppalapati Umesh Kumar Singh Department of Anaesthesiology Tata Main HospitalJamshedpur 831001JhārkhandIndia

BACKGrOUND Intrathecal bupivacaine is the traditional anesthetic drug used in spinal anesthesia for caesarean sections(CSs),but ropivacaine has emerged as a potential *** meta-analysis compares the efficacy and safety of intrathecal hyper-baric bupivacaine vs hyperbaric ropivacaine for cesarean *** To systematically evaluate and compare the efficacy and safety of intrathecal hyperbaric bupivacaine and hyperbaric ropivacaine for spinal anesthesia in *** A thorough search of electronic databases was carried out to find pertinent randomized controlled trials(rCTs)comparing intrathecal hyperbaric ropi-vacaine and hyperbaric bupivacaine during ***,Cochrane database,Google Scholar,and Scopus were searched,and papers from January 2000 to January 2024 were deemed eligible and filtered using predetermined inclusion and exclusion *** were assessed for methodological quality,and data were extracted for time to adequate anesthesia(sensory and motor blockade),duration of sensory and motor block,hemodynamic changes and side effect *** standardized mean difference with 95%CI was used for continuous *** variables were assessed using the Mantel-Haenszel test and the random effect model to compute the odds *** Total 8 rCTs were selected from a pool of 119 search results for *** meta-analysis evaluated pooled effect sizes and assessed heterogeneity among the *** primary objective was to compare key outcomes to identify any significant variances in efficacy and safety profiles between two local *** analysis revealed that the difference in the onset of sensory blockade between the two local anesthetics was statistically insignificant(P=0.1586).However,the onset of motor blockade appeared to be faster with bupivacaine(P=0.03589).Additionally,the regression of sensory and motor blockade occurred earlier in the ropivacaine ***,the duration of the first analgesic

关键词： ropivacaine Bupivacaine Anesthesia Spinal Cesarean section Meta-analysis

AN M/M/C rETrIAL QUEUEING SYSTEM WITH BErNOULLI VACATIONS

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Journal of Systems Science and Systems Engineering 2009年第2期18卷 222-242页

作者： B.krishna KUMAr r.rUKMANI V.THANGArAJ Department of Mathematics College of EngineeringAnna UniversityChennai600 025India Department of Mathematics Pachaiyappa's CollegeChennai600030India ramanujan Institute for Advanced Study in Mathematics University of MadrasChennai600 005India

In this paper, a steady-state Markovian multi-server retrial queueing system with Bernoulli vacation scheduling service is studied. Using matrix-geometric approach, various interesting and important system performance measures are obtained. Further, the probability descriptors like ideal retrial and vain retrial are provided. Finally, extensive numerical illustrations are presented to indicate the quantifying nature of the approach to obtain solutions to this queueing system.

关键词： retrial queue Bernoulli vacation matrix-geometric methods busy period vain retrial ideal retrial

relevance of epidemiology data in trauma management

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World Journal of Clinical Cases 2025年第9期13卷 65-67页

作者： krishna Kumar Govindarajan Department of Pediatric Surgery Jawaharlal Institute of Postgraduate Medical Education and ResearchPuducherry 605006India

Trauma is a major cause of morbidity and mortality across the globe accounting for significant health *** of trauma care revolves round prevention,planning and execution of safety *** of the actual data regarding the type of trauma,affected age group,timings of trauma occurrence,involved part of the body constitute the initial steps in the building of the composite overview of the epidemiology of *** succession,would be the measures directed towards avoidance of trauma and capacity building of trauma center.

关键词： Trauma Epidemiology Injury Prevention Triage registry Artificial Intelligence

rock-like behavior of biocemented sand treated under non-sterile environment and various treatment conditions

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Journal of rock Mechanics and Geotechnical Engineering 2021年第3期13卷 705-716页

作者： Meghna Sharma Neelima Satyam krishna rreddy Discipline of Civil Engineering Indian Institute of Technology IndoreIndore453552India Department of Civil Materialsand Environmental EngineeringUniversity of Illinois at ChicagoChicagoILUSA

Microbially induced calcite precipitation(MICP)is a recently developed technique for microbiological ground improvement that has been applied for mitigating various geotechnical ***,the major challenges,such as calcite precipitation uniformity,presence of different bacteria,cementation solution optimization for cost reduction,and implementation under non-sterile and uncontrolled field environment are still not fully explored and require detailed investigation before field *** study aims to address these challenges of MICP to improve the geotechnical properties of sandy *** series of experiments were conducted using poorly graded Narmada river(India)sand,which were subjected to various biotreatment schemes and tested for unconfined compressive strength(UCS),split tensile strength(STS),ultrasonic pulse velocity(UPV),hydraulic conductivity(after 6 d,12 d,and 18 d of treatment),and calcite *** microstructure of sand was examined through a scanning electron microscope(SEM).Initially,the sand was individually augmented with two non-pathogenic bacterial strains,***(S.)pasteurii and Bacillus(B.)*** stopped-flow injection method was adopted to provide cementation solutions at three different durations(treatment cycle)of 12 h,24 h,and 48 h and three different pore volumes(PVs)of 1,0.75,and *** pore volume here refers to the porosity which is expressed as a ratio,i.e.a porosity of 50%was used as *** results showed rock-like behaviors of biocemented sand with the UCS,STS,and UPV enhancement up to 2333 kPa,437 kPa,and 2670 m/s,*** hydraulic conductivity reduction of 96.6%was achieved by 12%of calcite formation after 18 d of treatment using Sporosarcina pasteurii,12-h treatment cycle,and one pore volume of cementation media in each ***,a 24-h treatment cycle and 0.5-pore volume cementation solution were found to be the optimal treatment which was effective and economical to achiev

关键词： Bacteria Microbially induced calcite precipitation (MICP) Soil stabilization Microstructure Calcite content

radiation-absorption,chemical reaction,Hall and ion slip impacts on magnetohydrodynamic free convective flow over semi-infinite moving absorbent surface

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Chinese Journal of Chemical Engineering 2021年第6期34卷 40-52页

作者： M.Veera krishna Department of Mathematics Rayalaseema UniversityKurnoolAndhra Pradesh 518007India

The investigation of radiation-absorption,chemical reaction,Hall and ion-slip impacts on unsteady MHD free convective laminar flow of an incompressible viscous,electrically conducting and heat generation/absorbing fluid enclosed with a semi-infinite porous plate within a rotating frame has been *** plate is assumed to be moving with a constant velocity in the direction of fluid movement.A uniform transverse magnetic field is applied at right angles to the porous surface,which is absorbing the fluid with a suction velocity changing with *** non-dimensional governing equations for present investigation are solved analytically making use of two term harmonic and non-harmonic *** graphical results of velocity,temperature and concentration distributions on the analytical solutions are displayed and discussed with reference to pertinent *** is found that the velocity profiles decreased with an increasing in Hartmann number,rotation parameter,the Schmidt number,heat source parameter,while it increased due to an increase in permeability parameter,radiation-absorption parameter,Hall and ion slip ***,the temperature profile is an increasing function of radiation-absorption parameter,whereas an increase in chemical reaction parameter,the Schmidt number Sc or frequency of oscillations decrease the temperature profile on ***,it is found that the concentration profile is decreased with an escalating in the Schmidt number or the chemical reaction parameter.

关键词： Chemical reaction Free convection Heat source Heat transfer Mass diffusion radiation absorption

Dielectric Function of Silicon Nanoclusters: role of Hydrogen

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Chinese Physics Letters 2011年第9期28卷 241-244页

作者： SIB krishna Ghoshal M.r.Sahar M.S.rohani Advanced Optical Material research Group Department of PhysicsFaculty of ScienceUniversiti Teknologi Malaysia81310 UTM SkudaiJohorMalaysia

Electronic and optical properties of small silicon quantum dots having 3 to 44 atoms per dot with and without surface passivation are investigated by computer simulation using the pseudo-potential *** empirical pseudo-potential Hamiltonian,a plane-wave basis expansion and a basic tetrahedral structure with undistorted local bonding configurations are *** structures of the quantum dots are relaxed and optimized before and after hydrogen *** is found that the gap increases more for a hydrogenated surface than the unpassivated ***,both quantum confinement and surface passivation determine the optical and electronic properties of Si quantum *** luminescence is probably due to the radiative recombination of electrons and holes in the quantum-confined *** effect of passivation of the surface dangling bonds by hydrogen atoms and the role of surface states on the gap energy is also *** results for the density of states,the dielectric function,the frequency dependent optical absorption cross section,the extinction coefficient and the static dielectric constants of the size are *** importance of the confinement and the role of surface passivation on the optical effects are discussed.

关键词： quantum dielectric extinction