检索结果-南通市图书馆

Oxidation of As(Ⅲ) by p.tassium p.rmanganate

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2007年第7期19卷 783-786页

作者： LI Na FAN Maohong Van Leeuwen Johannes saha Basudeb YANG Hongqun HUANG C. p. Dep.rtment of Civil Construction and Environmental Engineering Center for Sustainable Environmental Technology Iowa State University Ames Iowa 50011 USA. Center for Sustainable Environmental Technology Iowa State University Ames Iowa 50011 USA Dep.rtment of Chemistry Iowa State University Ames Iowa 50011 USA Dep.rtment of Chemical and Materials Engineering University of Alberta Edmonton Alberta T6G 2G6 Canada Dep.rtment of Civil and Environmental Engineering University of Delaware Newark DE 19716 USA

The oxidation of As（Ⅲ） with p.tassium p.rmanganate was studied under conditions including p., initial As（Ⅲ） concentration and dosage of Mn（Ⅶ）. The results have shown that p.tassium p.rmanganate was an effective agent for oxidation of As（Ⅲ） in a wide p. range. The p. value of tested water was not a significant factor affecting the oxidation of As（Ⅲ） by Mn（Ⅲ）. Although theoretical redox analyses suggest that Mn（Ⅶ） should have better p.rformance in oxidization of As（Ⅲ） within lower p. ranges, the exp.rimental results show that the oxidation efficiencies of As（Ⅲ） under basic and acidic conditions were similar, which may be due to the adsorp.ion of As（Ⅲ） on the Mn（OH）2 and MnO2 resulting from the oxidation of As（Ⅲ）.

关键词： arsenite arsenate oxidation p.tassium p.rmanganate

Analysis of a p.edator-p.ey model with herd behavior and disease in p.ey incorp.rating p.ey refuge

在线全文

学校读者我要写书评

暂无评论

International Journal of Biomathematics 2019年第1期12卷 133-171页

作者： Sangeeta saha G.p.Samanta Dep.rtment of Mathematics Indian Institute of Engineering Science and Technology Shibp.r Howrah-711103India

In this work,we have introduced an eco-ep.demiological model of an infected p.edator p.ey *** of p.ey refuge gives that a fraction of the infected p.ey is available to the p.edator for ***,to make the model more realistic to the environment,we have introduced strong Allee effect in the suscep.ible *** and p.sitivity of the solution have been *** stability conditions of the equilibrium p.ints have been found with the help.of Routh-Hurwitz criterion and it has been observed that if a p.ey p.p.lation is infected with a lethal disease,then both the p.ey(suscep.ible and infected)and p.edator cannot survive simultaneously in the system for any p.rametric *** disease transmission rate and the attack rate on the suscep.ible have an imp.rtant role to control the system *** different values of these two key p.rameters,we have got only healthy or disease-free or p.edation-free or a fluctuating disease-free or even a fluctuating p.edator-free system with some certain p.rametric conditions.

关键词： Allee effect herd behavior infected p.ey refuge extinction bifurcations

Effect of tool rotational sp.ed on the p.rticle distribution in friction stir welding of AA6092/17.5 SiCp.T6 comp.site p.ates and its consequences on the mechanical p.op.rty of the joint

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2020年第2期16卷 381-391页

作者： Uttam Acharya Barnik saha Roy Subhash Chandra saha Dep.rtment of Mechanical Engineering National Institute of Technology AgartalaBarjalaJiraniaWest Tripura799046India

This study investigates the effect of tool rotational sp.ed(TRS)on p.rticle distribution in nugget zone(NZ)through quantitative ap.roach and its consequences on the mechanical p.op.rty of friction stir welded joints of AA6092/17.5 SiCp.T6 comp.site.6 mm thick p.ates are welded at a constant tool tilt angle of 2°and tool traverse sp.ed of 1 mm/s by varying the TRS at 1000 rp.,1500 rp. and 2000 rp. with a tap.r p.n p.ofiled *** analysis shows large quantity of uniformly shap.d smaller size SiC p.rticle with lower average p.rticle area which are homogeneously distributed in the *** fragmentation of bigger size p.rticles has been observed because of abrading action of the hard tool and resulting shearing effect and severe stress generation due to the rotation of *** p.rticles occup. maximum area in the matrix comp.red to that of the base material(BM)due to the redistribution of broken p.rticles as an effect of *** migration of p.rticles towards the TMAZ-NZ transition zone has been also encountered at higher TRS(2000 rp.).The microhardness analysis dep.cts variation in average hardness from top.to bottom of the NZ,minimum for 1500 rp. and maximum for 2000 *** imp.ct strength at 1000 rp. and 1500 rp. remains close to that of BM(21.6 J)while 2000 rp. shows the accountable *** maximum joint efficiency has been achieved at 1500 rp.(84%)and minimum at 1000 rp.(68%)under tensile *** analysis shows mixed mode of failure for BM,1000 rp. and 1500 rp.,whereas 2000 rp. shows the brittle mode of failure.

关键词： Friction stir welding Aluminium matrix comp.site Tool rotational sp.ed p.rticle distribution Mechanical p.op.rty

Structural and electrical transp.rt p.op.rties of a rare earth double p.rovskite oxide:Ba_2ErNbO_6

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2014年第4期32卷 334-342页

作者： Rajesh Mukherjee Binita Ghosh Sujoy saha Chandrahas Bharti T.p.Sinha Dep.rtment of p.ysics Ramananda College Dep.rtment of p.ysics Bose Institute Sensor and Actuator Division CSIR-Central Glass and Ceramic Research Institute

The double p.rovskite oxide barium erbium niobate, Ba2ErNbO6 （BEN） was synthesized by solid state reaction technique. Rietveld refinement of the X-ray diffraction p.ttern of the samp.e showed cubic （Fm3m） p.ase at room temp.rature. Fourier trans-form infrared sp.ctrum showed two p.imary p.onon modes of the samp.e at around 387 and 600 cm-1. Raman sp.ctrum of the sam-p.e taken at 488 nm excitation wavelength showed four p.imary strong p.aks at 106, 382, 747 and 814 cm-1. Lorentzian lines with 10 bands were used to fit the Raman sp.ctrum. A group.theoretical study was p.rformed to assign all the Raman modes. Imp.dance sp.ctroscop. was ap.lied to investigate the ac electrical conductivity of BEN in a temp.rature range from 303 to 673 K and in a fre-quency range from 100 Hz-1 MHz. The dielectric relaxation mechanism was discussed in the frame work of p.rmittivity, conduc-tivity, modulus and imp.dance formalisms. The comp.ex p.ane p.ot of the imp.dance data was modeled by an equivalent circuit con-sisting of two serially connected R-Cp. units, （one for the grain and the other for the grain boundary）, each containing a resistor （R） and a constant p.ase element （Cp.）. The R-Cp. units were used to incorp.rate the non-ideal character of the p.larization p.enome-non instead of an ideal cap.citive behaviour. The relaxation time corresp.nding to dielectric loss was found to obey the Arrhenius law with activation energy of 0.85 eV. The frequency dep.ndent conductivity sp.ctra followed the Jonscher p.wer law. The Cole-Cole model was used to investigate the dielectric relaxation mechanism in the samp.e.

关键词： p.rovskites Rietveld refinement Raman sp.ctroscop. imp.dance sp.ctroscop. rare earths

Fresh and hardened p.op.rties of high-strength concrete incorp.rating byp.oduct fine crushed aggregate as p.rtial rep.acement of natural sand

在线全文

学校读者我要写书评

暂无评论

Frontiers of Structural and Civil Engineering 2021年第1期15卷 124-135页

作者： Dammika p.K.WELLALA Ashish Kumer saha p.abir Kumar SARKER Vinod RAJAYOGAN School of Civil and Mechanical Engineering Curtin UniversityPerthWA 6845Australia Regional Technical Manager HolcimPerthWA 6004Australia

This p.p.r p.esents the fresh and hardened p.op.rties of high-strength concrete comp.ising byp.oduct fine crushed aggregates(FCAs)sourced from the crushing of three different typ.s of rocks,namely granop.yre,basalt,and *** lowest void contents of the combined fine aggregates were observed when 40%to 60%of natural sand is rep.aced by the *** the rep.acement of 40%FCAs,the slump.and bleeding of concrete with a water-to-cement ratio of 0.45 decreased by ap.roximately 15%and 50%,resp.ctively,owing to the relatively high fines content of the *** 28 d comp.essive strength of concrete was 50 Mp. when 40%FCAs were *** slight decrease in tensile strength from the FCAs is attributed to the flakiness of the *** correlations between the sp.itting tensile and comp.essive strengths of normal concrete p.ovided in the AS 3600 and ACI 318 design standards are ap.licable for concrete using the FCAs as p.rtial rep.acement of *** maximum 56 d drying shrinkage is 520 microstrains,which is significantly less than the recommended limit of 1000 microstrains by AS 3600 for ***,the use of these byp.oduct FCAs can be considered as a sustainable alternative op.ion for the p.oduction of high-strength green concrete.

关键词： fine crushed aggregates quarry dust comp.essive strength sp.itting tensile strength drying shrinkage

Vertical Sediment Concentration Distribution in High-Concentrated Flows:An Analytical Solution Using Homotop. Analysis Method

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical p.ysics 2018年第9期69卷 367-378页

作者： Manotosh Kumbhakar Jitraj saha Koeli Ghoshal Jitendra Kumar Vijay p.Singh Dep.rtment of Mathematics Indian Institute of Technology KharagpurKharagpur 721302India Dep.rtment of Mathematics National Institute of TechnologyTiruchirappalliTamil Nadu 620015India Dep.rtment of Biological and Agricultural Engineering&Zachry Dep.rtment of Civil Engineering Texas A~M UniversityCollege StationTX 77843USA

Transp.rt of susp.nded sediment in op.n channel flow has an enormous imp.ct on real life situations,*** and management of reservoir sedimentation,geomorp.ic evolution such as dunes,rivers,and coastlines *** entails advection and *** diffusion is governed by the concep. of Fick’s law,which is based on the molecular diffusion theory,and the equation that rep.esents the distribution of sediment concentration is the advection-diffusion *** study uses the existing governing equation which considers different p.ases for solid and fluid,and then coup.es the two *** deal with high-concentrated flow,sediment and turbulent diffusion coefficients are taken to be different from each *** effect of hindered settling on sediment p.rticles is incorp.rated in the governing equation,which makes the equation highly *** study derives an exp.icit closed-form analytical solution to the generalized one-dimensional diffusion equation rep.esenting the vertical sediment concentration distribution with an arbitrary turbulent diffusion coefficient *** solution is obtained by Homotop. Analysis Method,which does not rely on the small p.rameters p.esent in the ***,the solution is validated by comp.ring it with the imp.icit solution and the numerical solution.A relevant set of laboratory data is selected to check the ap.licability of the model,and a close agreement shows the p.tential of the model in the context of ap.lication to high-concentrated sediment-laden op.n channel flow.

关键词： op.n channel flow diffusion equation hunt equation homotop. analysis method

A Novel Ap.roach with Time-Sp.itting Sp.ctral Technique for the Coup.ed Schrdinger–Boussinesq Equations Involving Riesz Fractional Derivative

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical p.ysics 2017年第9期67卷 301-308页

作者： S.saha Ray Dep.rtment of Mathematics National Institute Technology

In the p.esent p.p.r the Riesz fractional coup.ed Schr6dinger-Boussinesq （S-B） equations have been solved by the time-sp.itting Fourier sp.ctral （TSFS） method. This p.op.sed technique is utilized for discretizing the Schrodinger like equation and further, a p.eudosp.ctral discretization has been emp.oyed for the Boussinesq-like equation. Ap.rt from that an imp.icit finite difference ap.roach has also been p.op.sed to comp.re the results with the solutions obtained from the time-sp.itting technique. Furthermore, the time-sp.itting method is p.oved to be unconditionally stable. The error norms along with the grap.ical solutions have also been p.esented here.

关键词： coup.ed SchrSdinger-Boussinesq equations Riesz fractional derivative discrete fourier transform inverse discrete Fourier transform

Maximum mass of anisotrop.c charged strange quark stars in a higher dimensional ap.roach(D≥4)

在线全文

学校读者我要写书评

暂无评论

Chinese p.ysics C 2023年第1期47卷 271-292页

作者： A.saha K.B.Goswamiy B.Dasz p.K.Chattop.dhyayx Dep.rtment of p.ysics Alipurduar CollegeAlipurduarWest Bengal 736122India Dep.rtment of p.ysics Coochbehar Panchanan Barma UniversityWest Bengal 736101India

In this article,a new class of solutions of Einstein-Maxwell field equations of relativistic strange quark stars obtained in dimensions D≥4,is *** assume that the geometry of sp.ce-time is p.eudo-sp.eroid,embedded in Euclidean sp.ce of(D-1)*** MIT bag model equation of state(henceforth EoS)is emp.oyed to study the relevant p.op.rties of strange quark *** the causal and non-negative nature of the square of the radial sound velocity(vr2),we observe that some restrictions exist on the reduced radius(b/R),where R is a p.rameter related to the curvature of the sp.ce-time,and b is the radius of the *** sp.eroidal p.rameter A used here defines the metric p.tential of the grrcomp.nent,which is p.eudo-sp.eroidal in *** note that the p.essure anisotrop. and charge have some effects onλ.The maximum mass for a given surface density(ρs)or bag constant(B)assumes a maximum value in dimension D=5and decreases for other values of *** generalized Buchdahl limit for a higher dimensional charged star is also obeyed in this *** observe that in this model,we can p.edict the mass of a strange quark star using a suitable value of the electric charge(Q)and bag constant(B).Energy and stability conditions are also satisfied in this *** is also studied considering the dep.ndence of the Lagrangian p.rturbation of radial p.essure(Δp.)on the frequency of normal modes of *** tidal Love number and tidal de-formability are also evaluated.

关键词： strange star MIT bag model Einstein-Maxwell equations higher Dimension

Anisotrop.c strange quark star in Finch-Skea geometry and its maximum mass for non-zero strange quark mass(m_(s)≠0)

在线全文

学校读者我要写书评

暂无评论

Chinese p.ysics C 2023年第5期47卷 195-210页

作者： B.Das K.B.Goswami A.saha p.K.Chattop.dhyay Dep.rtment of p.ysics Coochbehar Panchanan Barma UniversityVivekananda StreetCoochbehar 736101West BengalIndia Dep.rtment of p.ysics Alipurduar CollegeAlipurduar 736122West BengalIndia

A class of relativistic astrop.ysical comp.ct objects is analyzed in the modified Finch-Skea geometry described by the MIT bag model equation of state of interior matter,p.1/3(ρ-4B),where B is known as the bag constant.B p.ays an imp.rtant role in determining the p.ysical features and structure of strange *** consider the finite mass of the strange quark(m_(s)≠0) and study its effects on the stability of quark matter inside a *** note that the inclusion of strange quark mass affects the gross p.op.rties of the stellar configuration,such as maximum mass,surface red-shift,and the radius of strange quark *** ap.ly our model p.ysically,we consider three comp.ct objects,namely,(ⅰ) VELA X-1,(ⅱ) 4U 1820-30,and(ⅲ) p.R J 1903+327,which are thought to be strange *** range of B is restricted from 57.55 to Bstable(MeV/fm3),for which strange matter might be stable relative to iron(^(56)Fe).However,we also observe that metastable and unstable strange matter dep.nd on B and *** energy conditions hold well in this *** in terms of the Lagrangian p.rturbation of radial p.essure is studied in this p.p.r.

关键词： comp.ct star strange star anisotrop. MIT EoS strange quark mass