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Effect of coaxial laser cladding parameters on bead formation

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International Journal of minerals,metallurgy and materials 2017年第5期24卷 550-556页

作者： A.I.Noskov A.Kh.Gilmutdinov R.m.Yanbaev Kazan National Research Technical University 10 Karl Marx Str. Kazan 420111 Republic of Tatarstan Russian Federation

We investigated the shape and morphology of nickel-based powder particles (Sulzer metco) and coatings produced by laser gas-powder deposition onto steel substrates. Laser deposition was performed using an LC-10 IPG-Photonics laser complex equipped with a 10-kW fiber laser. The shape and microstructure of the samples were studied using optical and electronic microscopy and X-ray diffraction analysis. The results showed that the deposition speed and laser power significantly influenced the shape and size of the beads. The depth of diffusion of nickel into the steel substrate after deposition was less than 20 μm; the microstructure of the resulting coating was fcc Fe3Ni. As a result, detailed information about the form and shape of the filler powder, modes of its deposition, and the resulting coating structure was obtained; this information is important for the production of high-quality products by additive technologies.

关键词： laser cladding additive manufacturing microstructure morphology bead formation

On Almost Controllability of Dynamical Complex Networks with Noises

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Journal of Systems Science & Complexity 2019年第4期32卷 1125-1139页

作者： CAI Ning HE ming WU Qiuxuan KHAN m.Junaid School of Auto mation Beijing University of Posts and TelecommunicationsBeijing 100876China Beijing Engineering Research Center of Post Intelligent Equipment Postal Scientific Research and Planning AcademyBeijing 100096China Key Laboratory of China's Ethnic Languages and Information Technology for ministry of Education Northwest Minzu UniversityLanzhou 730030China Rocket Force University of Engineering Xi'an 710025China School of Automation Hangzhou Dianzi UniversityHangzhou 310018China PN Engineering College National University of Sciences and TechnologyIslamabadPakistan

This paper discusses the controllability problem of complex *** is shown that almost any weighted complex network with noise on the strength of communication links is controllable in the sense of Kalman *** concept of... 详细信息

关键词： Communication link complex network controllability weight

Combining material characterization with single and multi-oxyanion adsorption for mechanistic study of chromate removal by cationic hydrogel

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Journal of Environmental Sciences 2011年第6期23卷 1004-1010页

作者： Irene m.C.Lo Samuel C.N.Tang Department of Civil and Environmental Engineering The Hong Kong University of Science and TechnologyHong KongChina

Cationic hydrogel with magnetic property was synthesized via radical polymerization and its removal capacity of chromate from contaminated water was found to be 200 mg/*** Fourier transform infrared spectroscopy（FT-IR） study,the mechanism of chromate removal by hydrogel was found to be non-specific adsorption,mainly due to ion exchange,as evidenced by the positively charged functional group,trimethyl ammonium-N＋（CH3）3,in the *** were accordingly determined by testing di？erent oxyanion adsorption onto the *** results of the chromate adsorption experiments illustrated that the amount of chromate adsorbed was nearly equal to that of the chloride released from the hydrogel,which is part of the evidence for ion *** and multi-oxyanion adsorption experiments were also performed,and it was demonstrated that ion removal was species independent,but charge dependent,another characteristic of the ion exchange *** was found that the same Langmuir model can be applied to best fit the findings of single and multi-oxyanion adsorption,which further indicates the mechanism of chromate removal is attributed to ion *** view of the above,the background anions compete for adsorption sites with chromate,evidenced by inhibitive chromate removal in the presence of background electrolytes in the batch studies,further echoing the ion exchange mechanism.

关键词： adsorption magnetic hydrogel mechanism ion exchange oxyanion

Experimental Investigation of Separation and Transition Processes on a High-Lift Low-Pressure Turbine Profile Under Steady and Unsteady Inflow at Low Reynolds Number

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Journal of Thermal Science 2010年第1期19卷 26-33页

作者： Satta F Simoni D Ubaldi m Zunino P Bertini F DImSET-Università di Genova Via Montallegro 1I-16145 GenovaItaly Avio R&D V.I Maggio99 I-10040 Rivalta(TO)-Italy

The effects induced by the presence of incoming wakes on the boundary layer developing over a high-lift low-pressure turbine profile have been investigated in a linear cascade at *** tested Reynolds number is 70000,typical of the cruise operating *** results of the investigations performed under steady and unsteady inflow conditions are *** unsteady investigations have been performed at the reduced frequency of f+=0.62,representative of the real engine operating *** aerodynamic loadings as well as boundary layer velocity profiles have been measured to survey the separation and transition *** analysis has been also performed to better understand the phenomena associated with the transition process under steady *** the unsteady case,a phase-locked ensemble averaging technique has been employed to reconstruct the time-resolved boundary layer velocity distributions from the hot-wire instantaneous signal *** ensemble-averaging technique allowed a detailed analysis of the effects induced by incoming wakes-boundary layer interaction in separation ***-resolved results are presented in terms of mean velocity and unresolved unsteadiness time-space plots.

关键词： boundary layer separation boundary layer transition wake-boundary layer interaction high-liftprofile low-pressure turbine

Devise of a W serpentine shape tube heat exchanger in a hard chromium electroplating process

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Chinese Journal of Chemical Engineering 2019年第1期27卷 218-225页

作者： Surasit Tanthadiloke Paisan Kittisupakorn Pannee Boriboonsri Iqbal m.mujtaba Department of Chemical Engineering Faculty of EngineeringChulalongkorn University School of Engineering University of Bradford

In a hard chromium electroplating process, a heat exchanger is employed to remove the heat produced from the high current intensity in an electroplating ***, a conventional U shape heat exchanger is installed in the bath, but it provides low heat ***, this study designs a novel W serpentine shape heat exchanger with identical heat transfer area to the conventional one for increasing heat removal *** performance of the heat exchange is tested with various flow velocities in a cross-section in range of 1.6 to 2.4 m·s^(-1).mathematical models of this process have been formulated in order to simulate and evaluate the heat exchanger *** results show that the developed models give a good prediction of the plating solution and cooling water temperature, and the novel heat exchanger provides better results at any flow *** addition, the W serpentine shape heat exchanger has been implemented in a real hard chromium electroplating *** data collected have shown that the new design gives higher heat removal performance compared with the U shape heat exchanger with identical heat transfer area; it removes more heat out of the process than the conventional one of about 23%.

关键词： W serpentine shape Hard chromium electroplating mathematical modeling Simulation Heat exchanger

Hylocomium splendens (Hedw.) *** Pleurozium schreberi (Brid.) *** trace element bioindicators:Statistical comparison of bioaccumulative properties

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Journal of Environmental Sciences 2013年第2期25卷 340-347页

作者： Sabina Doegowska Zdzisaw m.migaszewski Artur michalik Geochemistry and the Environment Division Institute of ChemistryJan Kochanowski University15GSwietokrzyska St25-406 KielcePoland

The principal objective of this study was to compare bioaccumulative properties of two terrestrial moss species Hylocomium splendens and Pleurozium schreberi from the Kielce area （south-central Poland）, using various statistical techniques. Forty-six moss samples from 23 sampling sites located within the city limits were analyzed for 33 trace elements. The results indicated that 17 elements （Ba, Ce, Co, Cu, Eu, Fe, Gd, Hg, La, mo, Nd, Ni, Pb, Pr, Sm, V, Y） dominated in H. splendens, whereas only three elements （mn, Sr, Zn） occurred in excessive amounts in P. schreberi. No differences in the distribution pattern of Dy, Er, Ho, Sn, Tb, Th and Yb were observed. The element concentration ratio （PI/Hy） varied from 0.50 to 1.19. For 14 elements （Ce, Co, Cu, Fe, Gd, Hg, La, mo, Nd, Ni, Pb, Sm, Th, V）, PI/Hy 〈 1; for 4 elements （Cd, mn, Sr, Zn）, PI/Hy 〉 1; for 7 elements （Ba, Dy, Er, Eu, Pr, Y, Yb）, PI/Hy = equalled 1. Czekanowski＇s method showed similarities in rare earth element concentrations for both moss species. The cluster analysis exhibited three significant clusters at D link /D max × 100 〈 50 for both moss species. Strong positive Spearman correlations between both moss species were recorded for the following pairs：Ba-Ba, Co-Co, Er-Er, Eu-Eu, Gd Gd, mn-mn, Ni-Ni, Pb-Pb, Pr-Pr, Sm-Sm, Th-Th, Y-Y, and Yb-Yb. Nonparametric tests （Sign test, Wilcoxon tests） showed statistically significant differences only for Cd, Ce, Co, Cu, Hg, mo, Ni, Pb and Sr. The scanning electron microscope study of H. splendens and P. schreberi revealed a different morphology of these species with no injuries.

关键词： biomonitoring trace elements moss species accumulative properties comparison

Anisotropy in dynamic recrystallization behavior of AZ31 magnesium alloy

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Journal of magnesium and Alloys 2022年第12期10卷 3470-3484页

作者： S.m.Fatemi S.Kheyrabadi H.Paul Department of metallurgy and materials Engineering Shahid Rajaee Teacher Training University136-16785 TehranIran Institute of metallurgy and materials Science Polish Academy of Sciences(PAS)25 Reymonta Street30-059 KrakowPoland

Deformation behavior as well as microstructural evolutions of a rolled AZ31 magnesium alloy with and without pre-existing extension twins were studied using compression tests which performed along different orientations at a temperature range of 25–350 ℃. The results implied that the initial texture not only influence the evolution of flow stress, but also change the size and fraction of recrystallized *** contrast to samples parallel to rolling and transverse directions, compression along normal direction resulted in a respectful softening at 150 ℃. The largest size and fraction of new grains at 250 ℃ were recorded after deformation along rolling direction, while the maximum flow softening was observed during deformation along normal direction. The anisotropy in microstructural evolutions was still retained at 350 ℃. Pre-existing twins could reduce the anisotropy of material in respect of flow stress as well as DRX progression, where TD sample showed the lowest DRX fraction at 250 ℃. Quaternion misorientation data obtained from EBSD analysis of pretwinned material implied that initial texture could not significantly influence final texture. A different misorientation distribution was realized after deformation of pretwinned material along ND and RD directions.

关键词： Slip Recrystallization Grain size Growth Twin

THE EFFECT OF DUAL-PHASE-LAG mODEL ON REFLECTION OF THERmOELASTIC WAVES IN A SOLID HALF SPACE WITH VARIABLE mATERIAL PROPERTIES

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Acta mechanica Solida Sinica 2013年第6期26卷 659-670页

作者： A.m.Zenkour D.S.mashat A.E.Abouelregal Department of mathematics Faculty of ScienceKing Abdulaziz UniversityP.O.Box 80203Jeddah 21589Saudi Arabia Department of mathematics Faculty of ScienceKafrelsheikh UniversityKafr El-Sheikh 33516Egypt Department of mathematics Faculty of ScienceMansoura UniversityMansoura 35516Egypt Department of mathematics College of Science and ArtsUniversity of AljoufEl-QurayatSaudi Arabia

The present article represents an analysis of reflection of P-wave and SV-wave on the boundary of an isotropic and homogeneous generalized thermoelastic half-space when the boundary is stress-free as well as isothermal. The modulus of elasticity is taken as a linear function of reference temperature. The basic governing equations are applied under four theories of the generalized thermoelasticity： Lord-Shulman （L-S） theory with one relaxation time, Green-Naghdi （G-N） theory without energy dissipation and Tzou theory with dual-phase-lag （DPL）, as well as the coupled thermoelasticity （CTE） theory. It is shown that there exist three plane waves, namely, a thermal wave, a P-wave and an SV-wave. The reflection from an isothermal stress-free surface is studied to obtain the reflection amplitude ratios of the reflected waves for the incidence of P- and SV-waves. The amplitude ratios variations with the angle of incident are shown graphically. Also the effects of reference temperature of the modulus of elasticity and dual-phase lags on the reflection amplitude ratios are discussed numerically.

关键词： generalized thermoelasticity dual-phase-lag variable material properties reflection waves

Initial impacts of rain gardens＇ application on water quality and quantity in combined sewer： field-scale experiment

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Frontiers of Environmental Science & Engineering 2017年第4期11卷 127-138页

作者： Isam Alyaseri Jianpeng Zhou Susan m. morgan Andrew Bartlett Department of Civil Engineering Al-Muthanna University Alsamawah Al-Muthanna 72001 Iraq Department of Civil Engineering Southern Illinois University Edwardsville Edwardsville IL 62026 USA Graduate School Southern Illinois University Edwardsville Edwardsville IL 62026 USA Agricultural Statistics Laboratory University of Arkansas Fayetteville AR 72701 USA

Green infrastructures such as rain gardens can benetit onsite reduction ot stormwater runott, leading to reduced combined sewer overflows. A pilot project was conducted to evaluate the impact of rain gardens on the water quality and volume reduction of storm runoff from urban streets in a combined sewer area. The study took place in a six-block area on South Grand Boulevard in St. Louis, missouri. The impact was assessed through a comparison between the pre-construction （2011/2012） and the post-construction （2014） phases. Shortly after the rain gardens were installed, the levels of total suspended solids, chloride, total nitrogen, total phosphorous, zinc, and copper increased. The level of mercury was lower than the detection level in both phases. E. coli was the only parameter that showed statistically significant decrease following the installation of rain gardens. The likely reason for initial increase in monitored water quality parameters is that the post-construction sampling began after the rain gardens were constructed but before planting, resulted from soil erosion and wash-out from the mulch. However, the levels of most of water quality parameters decreased in the following time period during the post-construction phase. The study found 76% volume reduction of stormwater runoff following the installation of rain gardens at one of studied sites. Statistical analysis is essential on collected data because of the encountered high variability of measured flows resulted from low flow conditions in studied sewers.

关键词： Rain gardens Bioretention Combined sewer Stormwater quality and quantity