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EXPERIMENTAL AND NUMERICAL ANALYSIS OF LAMINAR AND LOW TURBULENT FLOW DISTRIBUTIONS IN INLET DIVIDING HEADER OF SHELL AND TUBE HEAT EXCHANGER

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Journal of Hydrodynamics 2010年第4期22卷 494-502页

作者： k.NNAN k. RUDRAMOORTHY R. Department of Production Engineering PSG College of Technology

Flow distribution headers play a major role in heat *** selection of header diameter,branch pipe diameter,branch pipe spacing *** based on the designer＇s experience and general guide *** proper selection of the header dimensions will yield uniform flow distribution in heat exchangers,which in turn will enhance the heat exchanger *** this work.the flow distribution in branch pipes and the pressure variation across the branch pipes in laminar and low turbulence region is studied with two models of the inlet dividing *** the numerical analysis has been applied,its inability to predict the no flow condition through the branch pipes is *** results are presented in the form of flow rate ratio through branch pipes and nondimensional coefficients across branch pipes which are useful to apply the existing mathematical models for the present experimental setup.

关键词： shell and tube heat exchanger inlet dividing header uniform flow distribution experimental setups numerical analysis

Prognosis of surface subsidence affected by underground exploitation of ore vein deposits of Rozna type

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中国有色金属学会会刊：英文版 2005年第S1期15卷 304-309页

作者： k. Hortvik.L. Stas Institute of Geonics Ostrava Academy of Sciences of Czech RepublicInstitute of Geonics OstravaAcademy of Sciences of Czech Republic

Methods of prognosis of effect of underground mining on surface deformations are nowadays well elaborated both in Czech Republic and in the world for sedimentary, especially coal deposits in which as a rule mining technology of work.ng by long-walls is applied. However, prognosis of development of subsidence depression above ore vein deposits of slab-lik. type with solid adjacent rock. (deposits of Rozna type) work.d by underground method is a very specific problem and it has not been satisfactorily solved until now according to available professional literature. In connection with long-term surveying observations a newly conceived mechanism of genesis of subsidence depression above uranium deposit of Rozna has been described. Based on it a geomechanical model of deposit situation is elaborated which then enables by means of mathematical modelling of surface subsidence development to predict development of subsidence depression both in stage of deposit mining and in period after termination of mining work. Further research of this problem within grant project No. 105/02/P026 of Grant Agency of Czech Republic solving proposed is oriented in connection with further real surveying observations of subsidence depression development at verifying of this newly conceived mechanism of genesis and of further development of earth surface above uranium deposit of Rozna (at further verifying of scope and degree of its validity). The research according to expectation shall contribute generally to deeper conceiving of methodology of evaluation of earth surface movements after termination of mining for ore vein deposits exploited by underground method at similar conditions.

关键词： mining subsidence prognosis mathematical modelling

ADVANCES IN SusTAINABLE SECURITY SYSTEMS ENGINEERING WITH DRAMA THEORY (DT) Ⅱ

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Journal of Systems Science and Systems Engineering 2009年第4期18卷 403-422页

作者： Jason k. LEVY Nigel HOWARD Wilder School of Government and Public Affairs Virginia Commonwealth University Sheffield Hallam University

We put forth Drama Theory II （DT II） as a formal multiple participant decision mak.ng framework.that can be used to systematically model complex security challenges, and advance the field of Sustainable Security Systems Engineering. DT II is defined as a theory of ＂large world＂ pre-game communication and equilibrium selection. While game theoretic tools have been widely applied to resolve environmental conflicts and promote global security, traditional game theory assumes that decision mak.rs, options, and preferences are fixed. A mathematical treatment of k.y drama theoretic concepts （i.e. positions, intentions, doubts and dilemmas） is provided. The dynamics of the drama theoretic process are discussed and the expected equilibrium set is derived. The fundamental theorem of drama theory is proven and all theoretical results are applied to promote sustainable security solutions. It is emphasized that DT II represents a flexible systems engineering technique to address time-sensitive, multi-faceted, and complex multiple participant negotiations.

关键词： Drama Theory II sustainable security systems engineering game theory

Diagnosis of blood cancer using Mark.v chain Monte Carlo trace model

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International Journal of Biomathematics 2017年第3期10卷 61-76页

作者： k. Vaik.ndamoorthy v

Maximum probability of existence of cancer in human bodies is normally diagnosed very late, so that it is highly cumbersome for physicians to cure. Reliability in predicting cancer at initial stage is always needed, so that curing and medical recovery is possible. In this paper, an investigation was made to diagnose the presence of blood cancer using Mark.v Chain Monte Carlo （MCMC） trace model, which is most efficient on a wide range of complex Bayesian statistical models. The analysis was carried out using version 18 of SPSS AMOS software. Totally, 19 components were considered from the blood samples of 750 patients. Various factors such as class, age, lymphatics, block.of affarc, block.of lymph c, block.of lymph s, bypass, extravasate, regeneration of, early uptak. in, lym nodes dimin, lyre nodes enlar, change in lym, defect in node, changes in node, changes in strue special forms, dislocation, exclusion of node, number of nodes in blood cancer are analyzed. The maximum lik.lihood estimators of the parameters were derived and assessed their performance through a Monte Carlo simulation study. The convergence in prior distribution and posterior distribution tak.s irregular position in the diagrams and thus blood cancer is diagnosed through this model.

关键词： Monte Carlo sinmlation modeling trace cancer

Tensile and Impact Properties of Shielded Metal Arc Welded AISI 409M Ferritic Stainless Steel Joints

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Journal of Materials Science & Technology 2009年第2期25卷 181-186页

作者： k. Shanmugam A.k. Lak.hminarayanan V. Balasubramanian Centre for Materials Joining & Research (CEMAJOR) Department of Manufacturing Engineering Annamalai UniversityAnnamalai Nagar 608 002 Tamil Nadu India

The present study is concerned with the effect of filler metals such as austenitic stainless steel, ferritic stainless steel and duplex stainless steel on tensile and impact properties of the ferritic stainless steel conforming to AISI 409M grade. Rolled plates of 4 mm thick.ess were used as the base material for preparing single pass butt welded joints. Tensile and impact properties, microhardness, microstructure and fracture surface morphology of the joints fabricated by austenitic stainless steel, ferritic stainless steel and duplex stainless steel filler metals were evaluated and the results were reported. From this investigation, it is found that the joints fabricated by duplex stainless steel filler metal showed higher tensile strength and hardness compared to the joints fabricated by austenitic and ferritic stainless steel filler metals. Joints fabricated by austenitic stainless steel filler metal exhibited higher ductility and impact toughness compared with the joints fabricated by ferritic stainless steel and duplex stainless steel filler metals.

关键词： Ferritic stainless steel Shielded metal arc welding Tensile properties Impact toughness

Geochemistry of k.snau-Matasuk. lignites, Nagaur Basin, Rajasthan （India）

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International Journal of Coal Science & Technology 2016年第2期3卷 104-122页

作者： Prak.sh k. Singh Pramod k. Rajak.ramod k. Rajak.Vijay k. Singh Amiya S. Naik Coal & Organic Petrology Lab Centre of Advanced Study inGeology Banaras Hindu University VaranasiUttar Pradesh 221005 India

The distribution and verticals variation of geochemical components in the k.snau-Matasuk. lignites of Nagaur Basin, Rajasthan, were investigated using microscopy, proximate and ultimate analyses, Rock.Eval Pyrolysis, X-ray diffraction and Fourier Transform Infrared analyses, and major/minor/trace element determination. The relationship of elements with ash content and with macerals have also been discussed. These lignites are stratified, black. dominantly composed of huminite group macerals with subordinated amounts of liptinite and inertinite groups. They are classified as type-III k.rogen and are mainly gas prone in nature. The concentration （in vol%） of mineral matter is seen to increase towards upper part of seam and so is the concentration （in wt%） of the volatile matter, elemental carbon and sulphur. The common minerals present in these lignitesare mixed clay layer, chlorite, and quartz as identified by X-ray diffraction study. Compared with world average in brown coal, the bulk.concentration of Cu is anomalously high in most of the samples while Cd is 2-3 times high and Zn is high in one band. Based on interrelationship, different pyrite forms are noticed to have different preferential enrichment of various elements. The concentration of disseminated pyrite is more than the other pyrite forms and is followed by discrete pyrite grains and massive pyrite.

关键词： Geochemistry Macerals Trace elements k.snau-Matasuk. lignite Rajasthan

Hadro- and photo-production of η′ in quasi-free proton and neutron processes

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Chinese Physics C 2009年第12期33卷 1291-1295页

作者：黄飞 k. Nak.yama Department of Physics and Astronomy University of Georgia Athens GA 30602 USA Institut fr k.rnphysik.and Jlich Center for Hadron Physics Forschungszentrum Jlich D-52425 Jlich Germany

The η′ photoproduction process on quasi-free proton and neutron and the reaction NN→ η′NN are investigated within a relativistic effective Lagrangian approach to hadronic interactions. Resonances with spins 1/2 and 3/2 are considered together with the nucleonic and t-channel meson-exchange current contributions. In photoproduction processes, the S11 resonance is found to be responsible for the sharp rise of the cross sections near threshold. In pp → η′pp, it is found that the S11 resonance dominates the total cross section over the entire energy region considered. The spin observables, in particular the beam and target asymmetries, are shown to be very sensitive to the reaction mechanism and will help impose more stringent constraints on the model parameters.

关键词： η′ production free and quasi-free photoproduction meson production in NN collisions

Bile duct injury repair --earlier is not better

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Frontiers of Medicine 2015年第4期9卷 508-511页

作者： Vinay k. k.poor Department of Surgical Gastroenterology Sanjay Gandhi Postgraduate Institute of Medical Sciences Lucknow 226014 India

Bile duct injury is a common complication of cholecystectomy. The timing of bile duct injury repair remains controversial. A recent review conducted in France reported 39% complications and 64% failure after immediate repair in 194 patients compared with 14% complications and 8% failure after late repair in 133 patients. A national review of 139 consecutive early repairs conducted at five hepatopancreaticobiliary centers in Denmark.reported 4% mortality, 36% morbidity, and 42 restrictures （30%） at a median follow-up of 102 months, and only 64 patients （46%） demonstrated uneventful short-term and long-term outcomes. Most patients with bile duct injury present with bile leak.and sepsis; thus, early repair is not recommended. Percutaneous drainage of bile and endoscopic stenting are the mainstays of treatment of bile leak.because they convert acute bile duct injury into a controlled external biliary fistula. The ensuing benign biliary stricture should be repaired by a biliary surgeon after a delay of 4-6 week. once the external biliary fistula has closed.

关键词： bile duct injury cholecystectomy laparoscopic cholecystectomy

A Cooperative Approach of Frequency Regulation Through Virtual Inertia Control and Enhancement of Low Voltage Ride-through in DFIG-based Wind Farm

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Journal of Modern Power Systems and Clean Energy 2022年第6期10卷 1519-1530页

作者： Preeti Verma Seethalek.hmi k. Bharti Dwivedi Department of Electrical Engineering Institute of Engineering and TechnologyLucknow 226021Uttar PradeshIndiawhich is a constituent institute of Dr.A.P.J.Abdul Kalam Technical UniversityLucknowUttar Pradesh(U.P.)India IEEE

Doubly-fed induction generator(DFIG)-based wind farms(WFs)are interfaced with power electronic *** interfaces are attributed to the low inertia generated in the WFs under high penetration and that becomes prevalent in a fault ***,transient stability enhancement along with frequency stability in DFIG-based WFs is a major concern in the present *** this paper,a cooperative approach consisting of virtual inertia control(VIC)and a modified grid-side converter(GSC)approach for low voltage ride-through(LVRT)is proposed to achieve fault ride-through(FRT)capabilities as per the grid code requirements(GCRs)while providing frequency support to the grid through a synthetic *** proposed approach provides LVRT and reactive power compensation in the *** participation of the VIC in a rotor-side converter(RSC)provides frequency support to the DFIG-based *** combined approach supports active power compensation and provides sufficient k.netic energy support to the system in a contingency *** studies are carried out in MATLAB/Simulink.environment for symmetrical and unsymmetrical *** superiority of the proposed scheme is demonstrated through analysis of the performance of the scheme and that of a series resonance bridge-type fault current limiter(SR-BFCL).

关键词： Virtual inertia controller(VIC) doubly-fed induction generator(DFIG) fault ride-through(FRT)capability wind farm(WF) fault current limiter(FCL)