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Experimental Investigation of Micro Heat Pipes of Different Cross-sections Having same Hydraulic Diameter

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Journal of Thermal science 2008年第3期17卷 247-252页

作者： s.l.Mahmood M.A.R.Akhanda Department of Mechanical and Chemical Engineering Islamic University of Technology

Effects of micro heat pipe （MHP） cross-sections and orientations on its thermal performance are experimentally investigated in this study. Tests are conducted using five different cross-sections （circular, semicircular, elliptical, semi-elliptical and rectangular） of micro heat pipes having same hydraulic diameter of 3 rnm placed at three different inclination angles （0°, 45°, 90°）, where water is used as the working fluid. Evaporator section of the MHP is heated by an electric heater and the condenser section is cooled by circulation of water in an annular space between condenser section and the water jacket. Temperatures at different locations of the MHP are measured using five calibrated K type thermocouples. Heat supply is varied using a voltage regulator which is measured by a precision ammeter and a voltmeter. It is found that thermal performance tends to deteriorate as the MHP is flattened. Thus among all cross-sections of MHP, circular one exhibits the best thermal performance in terms of heat flux dissipation followed by semi-elliptical, semi-circular, elliptical and rectangular cross-sections. Moreover, its heat transfer capability also decreases with decreasing of its inclination angle. Finally, a correlation is developed which covers all the experimental data within ＋7%.

关键词： Micro heat pipe cross-section hydraulic diameter inclination.

Mechanical stress and deformation analyses of pressurized cylindrical shells based on a higher-order modeling

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Defence Technology（防务技术） 2023年第2期20卷 24-33页

作者： s.Mannani l.Collini M.Arefi Department of solid Mechanic Faculty of Mechanical EngineeringUniversity of KashanKashan87317-51167Iran Department of Engineering and Architecture University of ParmaParco Area Delle Scienze 181/A43124ParmaItaly

In this research,mechanical stress,static strain and deformation analyses of a cylindrical pressure vessel subjected to mechanical loads are *** kinematic relations are developed based on higherorder sinusoidal shear deformation *** stretching formulation is accounted for more accurate *** total transverse deflection is divided into bending,shear and thickness stretching parts in which the third term is responsible for change of deflection along the thickness *** axisymmetric formulations are derived through principle of virtual work.A parametric study is presented to investigate variation of stress and strain components along the thickness and longitudinal *** explore effect of thickness stretching model on the static results,a comparison between the present results with the available results of literature is *** an important output,effect of micro-scale parameter is studied on the static stress and strain distribution.

关键词： Principle of virtual work Thickness-stretched and shear deformable model stress and strain analyses Cylindrical pressure vessel

A Two-stage Kalman Filter for Cyber-attack Detection in Automatic Generation Control system

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Journal of Modern Power systems and Clean Energy 2022年第1期10卷 50-59页

作者： Ayyarao s.l.V.Tummala Ravi Kiran Inapakurthi GMR Institute of Technology RajamSrikakulamAndhra PradeshIndia Raghu Engineering College DakamarriVisakhapatnamAndhra PradeshIndia

Communication plays a vital role in incorporating smartness into the interconnected power ***,historical records prove that the data transfer has always been vulnerable to *** these cyber-attacks are identified and cordoned off,they may lead to black-out and result in national security *** paper proposes an optimal two-stage Kalman filter(OTs-KF)for simultaneous state and cyber-attack estimation in automatic generation control(AGC)***/cyber-attacks are modeled as unknown inputs in the AGC *** types of cyber-attacks,i.e.,false data injection(FDI),data replay attack,denial of service(Dos),scaling,and ramp attacks,are injected into the measurements and estimated using *** the load variations of each area are seldom available,OTs-KF is reformulated to estimate the states and outliers along with the load variations of the *** proposed technique is validated on the benchmark two-area,three-area,and five-area power system *** simulation results under various test conditions demonstrate the efficacy of the proposed filter.

关键词： Cyber-security automatic generation control(AGC) load frequency control false data injection cyber-attack detection

Processes underlying the laser photochromic effect in colloidal plasmonic nanoparticle aggregates

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Chinese Physics B 2020年第3期29卷 412-419页

作者： A E Ershov V s Gerasimov I l Isaev A P Gavrilyuk s V Karpov Institute of Computational Modeling sB RAs 660036KrasnoyarskRussia siberian Federal University Krasnoyarsk660041Russia Kirensky Institute of Physics Federal Research Center KSC SB RAS660036KrasnoyarskRussia siberian state University of science and Technology Krasnoyarsk 660014Russia

We have studied the dynamic and static processes occurring in disordered multiparticle colloidal Ag aggregates with natural structure and affecting their plasmonic absorption spectra under pico-and nanosecond pulsed laser radiations, as well as the physical origin responsible for these processes. We have shown that depending on the duration of the laser pulse,the mechanisms of laser modification of such aggregates can be associated both with changes in the resonant properties of the particles due to their heating and melting(picosecond irradiation mode) and with the particle shifts in the resonant domains of the aggregates(nanosecond pulses) which depend on the wavelength, intensity, and polarization of the *** mechanisms result in formation of a narrow dip in the plasmonic absorption spectrum of the aggregates near the laser radiation wavelength and affect the shape and position of the dip. The effect of polydispersity of nanoparticle aggregates on laser photochromic reaction has been studied.

关键词： nanoparticle surface plasmon resonance photochromic process pulsed laser radiation

Three New spiral Galaxies with Active Nuclei Producing Double Radio lobes

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Research in Astronomy and Astrophysics 2023年第3期23卷 46-53页

作者： X.Y.Gao Z.s.Yuan J.l.Han Z.l.Wen s.s.shan National Astronomical Observatories Chinese Academy of SciencesBejing 10011China CAs Key laboratory of FAsT National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China school of Astronomy University of Chinese Academy of SciencesBeijing 100049China

Double radio lobes are generally believed to be produced by active nuclei of elliptical ***,several double-lobed radio sources have been solidly found to be associated with spiral *** cross-matching~9×105 spiral galaxies selected from the sloan Digital sky survey DR8 data with the full 1.4 GHz radio source catalogs of NRAO VlA sky survey and Faint Images of the Radio sky at Twenty-centimeters,we identify three new spiral galaxies:J0326-0623,J1110+0321 and J1134+3046 that produce double radio lobes,and five doublelobed spirals previously *** combining the newly discovered and all the other known cases in literature,we confirm the relation that more massive spiral galaxies could produce more powerful radio *** find that most of these spiral galaxies are located in a galaxy group or a poor cluster,in which the environment is denser than in the field,and about half of them are the central brightest galaxies in their parent *** therefore suggest that the environment is one of the key factors for a spiral to produce double radio lobes.

关键词： galaxies galaxy massive

Fatigue Behaviour of Naval steel Under seawater Environmental and Variable loading Conditions

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Journal of Iron and steel Research International 2011年第5期18卷 64-69页

作者： C Gheorghies l Palaghian s Baicean M Buciumeanu s Ciortan Department of Physics University "Dunarea de Jos" of Galati Department ofMechanical Engineering University "Dunarea de Jos" of Galati

The way to characterize the behaviour of a naval steel grade E36 subjected to the corrosive fatigue process is investigated. The tests were carried out by bending fatigue of plate specimens with thickness of 10 mm in the corrosive environment consisting of an aqueous solution of 3.5% of NaCl which is similar to seawater. Experimental results show that the principal mechanism of degradation of the superficial layer is based on the pit evolution,evidenced by electrochemical,micro and macro structural timely changes such as evolution of electrode potential,evolution of current density,polarization resistance,anodic and cathodic parameters,and dislocation density evolution.

关键词： naval steel fatigue pitting corrosion structure

Combinatorial genetics methods for discovering high-order regulatory combinations and engineering genetic drivers for neural differentiation

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Neural Regeneration Research 2021年第12期16卷 2403-2404页

作者： Dawn G.l.Thean Alan s.l.Wong laboratory of Combinatorial Genetics and synthetic Biology School of Biomedical SciencesThe University of Hong KongPokfulamHong Kong Special Administrative RegionChina Department of Electrical and Electronic Engineering The University of Hong KongPokfulamHong Kong Special Administrative RegionChina

Diving into the search for effective cell differentiation factors:Researchers are still striving to find better therapeutics to revert or slow down the progression of neurological disorders such as Parkinson’s disease,Alzheimer’s disease,and Huntington’s *** disorders are the result of neuronal cell death in different parts of the *** or treatments used to relieve the symptoms in patients have not been well *** do not recover the damaged neural tissues and can result in unwanted side effects.

关键词： Huntington neural Alzheimer

Cell transmission model based traffic signal timing in oversaturated conditions

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Journal of Central south University 2013年第4期20卷 1129-1136页

作者：王屏 l. s. Jones 杨群 s. Gurupackiam Key laboratory of Road and Traffic Engineering of Ministry of Education (Tongji University) Department of Civil Construction and Environmental Engineering the University of Alabama

In order to investigate enhancements to cell transmission model (CTM) as a tool for traffic signal timing in oversaturated conditions, randomly distributed saturation flow rates and arrival rates were used instead of constant values to simulate traffic flow movement, estimate the average delay of the network and search for an optimal traffic signal timing plan. A case study was given to demonstrate that the proposed methodology can capture unique phenomena in oversaturated conditions such as forward wave, spillback and lane entrance blockage. The results show that CTM underestimates travel time by 25% when compared to simtraffic, while the enhanced CTM underestimates by only 3%. A second case study shows that a dynamic signal timing plan is superior to a fixed signal timing plan in the term of average delay.

关键词： oversaturated flow conditional cell transmission model traffic signal timing spillback blockage

Nano sized Copper selenide Thin Film Pre-Cursor by A liquid Phase Chemical Growth Process

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稀有金属材料与工程 2012年第S1期41卷 24-27页

作者： Deshmukh l P Deshmukh s K Thin Film and solar studies Research laboratory Department of PhysicsSolapur UniversitySolapur-413 255M.S.India

The deposition of copper selenide(Cuse)thin films was carried out using liquid phase chemical bath deposition process at the optimized growth parameters as:60℃deposition temperature,90 minutes deposition time,pH equal to 10.5±0.1 and 72±2 r/min speed of mechanical *** as-grown deposits exhibited excellent uniformity and physical adherency with the substrate surface and are smooth and diffusely reflecting with colour changing from yellowish orange to dark chocolate during *** layer is of the order of 300 nm *** EDs analysis technique gave film composition to be nearly stoichiometric(Cu=47.89%,se=52.11%).An X-ray diffraction analysis showed Cuse to be polycrystalline hexagonal with a good match of d-values and intensities of *** crystallite size is in the nanorange(50-60 nm).The as-deposited Cuse exhibited a high coefficient of absorption(α=105cm-1)with a direct optical band gap of 1.81 *** to other chalcogenides,Cuse films exhibit low resistance;room temperature electrical resistivity being 1.55×103?*** electrical conductivity decreased with increase in temperature up to 473 K;showing totally unusual behaviour from that of the semiconducting *** thermo probe measurements showed n-type conduction of the samples.

关键词： lPCBD solar absorber Cu-deficient hexagonal metal like behaviour direct transition