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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

Microstructural evolution and mechanical properties of nanostructured Cu-Al-Ni shape memory alloys

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International Journal of Minerals,Metallurgy and Materials 2012年第4期19卷 333-338页

作者： M. Izadinia k. Dehghani Mining and Metallurgical Engineering Department Amirkabir University of Technology

The melt spinning technique, with an applied cooling rate of about 106 k.s, was used to produce a nanostructured Cu＋13.2Al＋ 5.1Ni （in wt%） shape memory alloy. The properties of nanostructured ribbons were then compared with those of conventional coarse struc- ture. The microstructural evolution was characterized using scanning electron microscopy （SEM）, atomic force microscopy （AFM） and X-ray diffraction （XRD） techniques. Microhardness measurements indicate a two-fold increase in hardness because of the produced nanos- lructure. Comparing to its coarse structure, the nanostructured Cu-A1-Ni shape memory alloy exhibited the enhanced mechanical properties including a ductility of 6.5% and a pronounced plateau in the stress-strain curve.

关键词： copper allosy shape memory effect melt spinning mechanical properties microstructural evolution

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

Perioperative neurocognitive dysfunction and role of dexmedetomidine in radical colon cancer surgery in elderly patients

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World Journal of Gastrointestinal Surgery 2025年第3期17卷 6-13页

作者： Chandra k.Pandey Abhishek.k.mar Department of Anaesthesiology Medanta Hospital LucknowLucknow 226030Uttar PradeshIndia Department of Anaesthesia King George Medical UniversityLucknow 226003Uttar PradeshIndia

This article explored the application of dexmedetomidine(Dex),a highly selective alpha-2 agonist,in managing postoperative cognitive dysfunction(POCD)in elderly patients undergoing radical colon cancer *** is associated with a progressive decline in physiological functions and an increased risk.of adverse surgical outcomes,including POCD,which encompasses many neurocognitive disorders that manifest during the perioperative *** aging population is at a higher risk.for POCD,which can lead to prolonged hospital stays,delayed recovery,and increased healthcare *** has neuroprotective,opioid-sparing,and sympatholytic properties,which reduces the incidence and severity of *** was introduced for sedation in patients receiving mechanical ventilation but has since been adopted in anesthesia due to its multifaceted *** appli-cation extends to sedation,analgesia,maintenance of anesthesia,and controlling *** neuroprotective and anti-inflammatory effects have been explored in managing *** article discussed the broad range of patient and procedure-related risk.factors for *** identification and intervention are crucial to prevent the progression of POCD,which can have severe physical,psychological,and economic *** article underscored the importance of a mul-tidisciplinary approach in managing POCD,involving the optimization of comor-bidities,depth of anesthesia monitoring,hemodynamic stability,and cerebral oxygenation monitoring.

关键词： Colon cancer Dexmedetomidine General anesthesia Elderly Radical colon cancer surgery Cognitive function

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

Volumetric and Viscometric Studies of 4-Aminobutyric Acid in Aqueous Solutions of Salbutamol Sulphate at 308.15, 313.15 and 318.15k

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Chinese Journal of Chemical Engineering 2009年第5期17卷 796-804页

作者： k. Rajagopal S.S. Jayabalak.ishnan Departrnent of Physics Government College ofEngg Tirunelveli-627007 Tamil Nadu India Department of Physics P.S.R. Engg. College Sivakasi Tamil Nadu India

Density （ρ） and viscosity （η） measurements were carried out for 4-aminobutyric acid in 0.0041,0.0125 and 0.0207 mol·L-1 aqueous salbutamol sulphate at T=308.15,313.15 and *** measured values of density and viscosity were used to estimate some important parameters such as apparent molar volume Vφ,limiting apparent molar volume Vφ0,transfer volume △Vφ0,hydration number Hn,second derivative of infinite dilution of partial molar volume with temperature 2Vφ0/T2,viscosity B-coefficients,variation of B with temperature dB/dT,free energy of activation per mole of solvent △μ10＊ and solute △μ20＊,activation entropy △S20＊ and activation enthalpy △H20＊ of the amino *** parameters have been interpreted in terms of solute-solute and solute-solvent interactions and structure mak.ng/break.ng ability of solutes in the given solution.

关键词： density standard partial molar volume hydration ntnZnber relative viscosity B-coefficient activation parameters