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Effect of the initial EcAP passes on crystal texture and residual stresses of 5083 aluminum alloy

international Journal of minerals,metallurgy and materials 2020年第6期27卷 801-808页

作者： L.Romero-Reséndiz A.Flores-Rivera i.A.Figueroa c.Braham c.Reyes-Ruiz i.Alfonso G.González instituto de investigaciones en materiales Universidad Nacional Autónoma de MéxicoCd.de México 04510México Procédés et ingénierie en mécanique et matériaux Arts et MétiersParis 75013France Departamento de Diseño y manufactura Facultad de IngenieríaUniversidad Nacional Autónoma de MéxicoPIIT Apodaca 66629México instituto de investigaciones en materiales Unidad MoreliaUniversidad Nacional Autónoma de MéxicoMorelia 58190México

To produce a highly refined microstructure,several metals or alloys have been processed via equal-channel angular pressing(EcAP).in this work,the mechanical and microstructural changes of the 5083 aluminum alloy in H11 condition after processed by two EcAP passes were *** EcAP H13 steel die with an inner angle(α)of 120°and outer curvature(β)of 20°was *** microstructural changes were associated with the loss of texture *** morphologies of the mg2Si andα-Al(mn,Fe)Si precipitates for the sample at the initial condition were similar to those subjected to two EcAP *** peak broadening measured by X-ray diffraction revealed an increment of both grain refinement and *** the second extrusion pass,the hardness increased by 62%compared with the initial ***,the heterogeneous hardness behavior was compatible with a highly localized dislocation *** two EcAP passes,shear parallel bands were observed to be at nearly 45°to the extrusion *** evaluation of first-order residual stress as a function of the depth of the analyzed sample displayed compressive or tensile values,depending on the measured *** the plastic deformation applied,the first and second-order residual stresses exhibited significant ***-Hall plots showed positive slopes,indicating an increment in the microstrain.

关键词： aluminum alloy equal-channel angular pressing texture microstructure residual stress

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Second law analysis of Blasius flow with nonlinear Rosseland thermal radiation in the presence of viscous dissipation

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Propulsion and Power Research 2019年第3期8卷 234-242页

作者： m.i.Afridi m.Qasim Department of mathematics COMSATS Institute of Information TechnologyIslamabad45550Pakistan

in the present article,we perform the second law analysis of classical Blasius flow accounting the effects of nonlinear radiation and frictional *** two-dimensional boundary layer momentum and energy equations are converted to self-similar equations using similarity *** set of resultant ordinary differential equations are solved *** numerical results obtained from solutions of dimensionless momentum and energy equations are used to calculate the entropy generation number and Bejan *** velocity profile f'(ξ),temperature distributionθ(ξ),entropy production number Ns and Bejan number Be are plotted against the physical flow parameters and are discussed in ***,for the sake of validation of our numerical code,the obtained results are reproduced using matlab built-in boundary value solver bvp4c resulting in an excellent *** is observed that entropy generation is increasing function of heating parameter,Prandtl number,Eckert number and radiation ***,it is observed that entropy generation can be minimized by reducing the operating temperatureΔT=T_(w)−T_(∞).

关键词： Second law analysis Boundary layer Nonlinear Rosseland thermal radiation Energy dissipation bvp4c

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Separation of spermatozoa fromerythrocytes using their tumblingmechanism in a pinch flow fractionationdevice

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microsystems & Nanoengineering 2019年第1期5卷 474-480页

作者： Johanna T.W.Berendsen Jan c.T.Eijkel Alex m.Wetzels loes i.Segerink BiOS Lab on a chip Group MESA+Institute for NanotechnologyTechnical Medical CentreUniversity of TwenteEnschedeThe Netherlands Department of Obstetrics and Gynaecology Radboud University Nijmegen Medical CentreNijmegenThe Netherlands

men suffering from azoospermia can father a child,by extracting spermatozoa from a testicular biopsy *** main complication in this procedure is the presence of an abundance of ***,the isolation of the few spermatozoa from the sample is manually performed due to ineffectiveness of filtering methods,making it time consuming and labor *** spermatozoa are smaller in both width and height than any other cell type found in the sample,with a very small difference compared with the erythrocyte for the smallest,making this not the feature to base the extraction ***,the length of the spermatozoon is 5×larger than the diameter of an erythrocyte and can be *** we propose a microfluidic chip,in which the tumbling behavior of spermatozoa in pinched flow fractionation is utilized to separate them from the *** show that we can extract 95%of the spermatozoa from a sample containing 2.5%spermatozoa,while removing around 90%of the *** adjusting the flow rates,we are able to increase the collection efficiency while slightly sacrificing the purity,tuning the solution for the available sample in the clinic.

关键词： erythrocytes flow utilized

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B(E2) value of even-even ^(108-112)Pd isotopes by interacting boson model-1

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chinese Physics c 2014年第2期38卷 24-28页

作者： i.Hossain H.Y.Abdullah i.m.Ahmad m.A.Saeed Department of Physics Rabigh College of Science and Arts King Abdulaziz University Department of Physics College of Education Scientific Department Salahaddin University Department of Physics College of Education Mosul University Department of Physics Faculty of Science Universiti Teknologi Malaysia

This work studies the systematic reduced transition probabilities B（E2）↓, intrinsic quadrupole moments and deformation parameters of Pd isotopes with even neutrons from N =62 to 66. The downward reduced transition probabilities B（E2）↓from gamma transition 8^＋to 6^＋, 6^＋ to 4^＋, 4^＋ to 2^＋ and 2^＋ to 0＋states of even-even108 112Pd isotopes were calculated by the interacting Boson model（iBm-1） and compared with the available previous experimental results. The ratio of the excitation energies of the first 4＋and the first 2＋excited states, R4/2, is also studied for the classification of symmetry of these nuclei. Furthermore we have studied systematically the transition rate R = B（E2： L＋ →（L 2）＋）/B（E2 ： 2＋ →0＋） of some of the low-lying quadrupole collective states in comparison with the available experimental data. The associated quadrupole moments and deformation parameters have been calculated. The results of this calculation are in good agreement with the corresponding available experimental data. The108 112Pd isotopes show the O（6） symmetry.

关键词： B(E2) ground-states Pd isotopes.quadrupole moments deformation parameter

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mixing features in an electromagnetic rectangular micromixer for electrolyte solutions

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Journal of Hydrodynamics 2017年第4期29卷 668-678页

作者： m.m.Wen c.N.Kim Department of mechanical Engineering Graduate School Kyung Hee University Department of mechanical Engineering College of Engineering Kyung Hee University

in this study, a new magnetohydrodynamic（mHD） mixer for electrolyte solutions with pumping function is reported, and the mixing performance of the device for two different electrolyte solutions is numerically examined in a uniform magnetic field. Application of different potentials to different electrodes allows the current to be induced. The combination of the induced current and magnetic field yields lorentz force, resulting in the fluid motion. The numerical simulation for the flows in the device is carried out with commercial software cFX. The validity of cFX code for the present numerical model is presented. The mixing performance of the fluids is investigated in many different cases with different combinations of input voltage of the electrode. This study shows that the mixing performance can be enhanced by applying spatially alternating positive and negative voltages to the electrodes. The present simulation results show that with a magnetic field intensity lower than 0.5 T, a voltage difference smaller than 2.0 V, and an electric conductivity of electrolyte solution of 1.5 S/m the pumping capabilities ranging 1.6×10^（-7）-3.6×10^（-6） kg/s and the mixing indexes higher than 0.90 can be obtained with sophisticated designs of the micromixer.

关键词： mixer electrolyte solution lorentz force cFX

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Are Ni/and Ni5Fe1/biochar catalysts suitable for synthetic natural gas production?A comparison with g-Al2O3 supported catalysts

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Green Energy & Environment 2023年第3期8卷 744-756页

作者： m.Gonzalez-castano c.morales J.c.Navarro de miguel J.H.Boelte O.Klepel J.i.Flege H.Arellano-García Department of Process and Plant Technology Brandenburg University of Technology(BTU)Cottbus-SenftenbergPlatz der Deutschen 1Cottbus03046Germany Applied Physics and Semiconductor Spectroscopy Brandenburg University of Technology Cottbus-SenftenbergKonrad-Zuse-Strasse 1Cottbus03046Germany Department of inorganic chemistry Institute of Materials Science of SevilleConsejo Superior de Investigaciones Cientificas(CSIC)Universidad de Sevilla(US)Avenida Americo Vespucio 49Seville41092Spain institute of materials chemistry Brandenburg University of Technology Cottbus–SenftenbergUniversitatsplatz 1SenftenbergD-01968Germany

Among challenges implicit in the transition to the post-fossil fuel energetic model,the finite amount of resources available for the technological implementation of cO_(2) revalorizing processes arises as a central *** development of fully renewable catalytic systems with easier metal recovery strategies would promote the viability and sustainability of synthetic natural gas production circular *** Ni and NiFe catalysts supported over g-Al_(2)O_(3) oxide as reference materials,this work evaluates the potentiality of Ni and NiFe supported biochar catalysts for cO_(2) *** development of competitive biochar catalysts was found dependent on the creation of basic sites on the catalyst *** lower Turn Over Frequencies than Ni/Al catalyst,the absence of basic sites achieved over Ni/c catalyst was related to the depleted catalyst *** NiFe catalysts,analogous Ni_(5)Fe_(1) alloys were constituted over both alumina and biochar *** highest specific activity of the catalyst series,exhibited by the NiFe/c catalyst,was related to the development of surface basic sites along with weaker NiFe-c interactions,which resulted in increased Ni0:NiO surface populations under reaction *** summary,the present work establishes biochar supports as a competitive material to consider within the future low-carbon energetic panorama.

关键词： Biochar catalysts carbon catalysts Ni catalysts NiFe alloy Bimetallic catalysts Synthetic natural gas cO_(2)methanation

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Hard rock tunnel boring machine penetration test as an indicator of chipping process efficiency

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Journal of Rock mechanics and Geotechnical Engineering 2017年第4期9卷 611-622页

作者： m.c. Villeneuve Department of Geological Sciences University of Canterbury Christchurch 8140 New Zealand

The transition from grinding to chipping can be observed in tunnel boring machine(TBm) penetration test data by plotting the penetration rate(distance/revolution) against the net cutter thrust(force per cutter) over the full range of penetration rates in the *** penetration test data to the geological and geomechanical characteristics of rock masses through which a penetration test is conducted provides the ability to reveal the efficiency of the chipping process in response to changing geological *** test data can also be used to identify stress-induced tunnel face *** research shows that the strength of the rock is an important parameter for controlling how much net cutter thrust is required to transition from grinding to *** also shows that the geological characteristics of a rock will determine how efficient chipping occurs once it has *** particular,geological characteristics that lead to efficient fracture propagation,such as fabric and mica contents,will lead to efficient *** findings will enable a better correlation between TBm performance and geological conditions for use in TBm design,as a basis for contractual payments where penetration rate dominates the excavation cycle and in further academic investigations into the TBm excavation process.

关键词： Penetration rate Grinding chipping Geological characteristics Face stability

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Natural compounds may contribute in preventing SARS-coV-2 infection:a narrative review

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Food Science and Human Wellness 2022年第5期11卷 1134-1142页

作者： maria Eleonora Bizzoca Stefania Leuci.m.c.ele Davide mignogna Eleonora lo muzio Vito carlo Alberto caponio lorenzo lo muzio Department of clinical and Experimental medicine University of FoggiaFoggia 71122Italy Department of Neurosciences Reproductive and Odontostomatological SciencesFederico Ⅱ University of NaplesNaples 80131Italy Department of Neuroscience and Rehabilitation University of FerraraFerrara 44121Italy c.i.N.B.O.(consorzio interuniversitario Nazionale per la Bio-Oncologia) Chieti 66100Italy

coronavirus pandemic infection is the most important health issue *** disease 2019 is a contagious disease characterized by severe acute respiratory syndrome coronavirus *** date,excluding the possibility of vaccination,against SARS-coV-2 infection it is possible to act only with supportive care and non-virus-specific treatments in order to improve the patient’s *** industry is investigating effects of medicinal plants,phytochemical extracts and aromatic herbs to find out natural substances which may act as antiviral *** studies have revealed how these substances may interfere with the viral life cycle,viral entry,replication,assembly or discharge,as well as virus-specific host targets or stimulating the host immune system,reducing oxidative stress and inflammatory response.A natural compound can be used as a prophylaxis by people professionally exposed to the risk of contagion and/or positive patients not in intensive *** aim of this paper is to perform a narrative review of current literature in order to summarize the most studied natural compounds and their modes of action.

关键词： Natural compounds SARS-coV-2 cOViD-19 Prevention infectious disease Phytochemicals medicinal plants

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Physical and Dielectric Properties of Some Nonionic Surfactants

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Journal of materials Science & Technology 1998年第4期14卷 361-367页

作者： El-Anwar, i.m. El-Henawii, S.A. National Research center Dokki Cairo Egypt Faculty of Science Helwan University Egypt

Fatty acid esters have been prepared by reacting the acid c//1//8 with polyethylene glycols having varying numbers of oxyethylene units (4-88 units) by the direct esterification reaction method. Surface and interfacial tensions were studied at various experimental conditions, including, concentration, temperature and chemical constitution of the surfactant. critical micelle concentrations (cmc), surface excess and residual area occupied by each surface active agent molecule A have been calculated by using Gibb's equations. cmc values range from 10 to 55 multiplied by 10** minus **5 mole/L for all studied agents, while the residual area occupied by each molecule varies from 0.6 to 1.5 nm**2. Variation of cmc of some of these agents with temperature have been also examined and the obtained data were used to calculate the heat of micellization delta H//m and the entropy change during micellization delta S//m. Values of delta H//m vary from 14.63 kJ/mole to 2.717 kJ/mole depending on the chemical constitution of the agent under consideration. The apparent dipole moments mu of three surfactant were measured following the Headstrand's method. (Edited author abstract) 23 Refs.

关键词： Surface active agents

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Unveiling bulk and surface radiation forces in a dielectric liquid

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Light(Science & Applications) 2022年第5期11卷 925-934页

作者： N.G.c.Astrath G.A.S.Flizikowski B.Anghinoni L.c.malacarne m.L.Baesso T.Požar m.Partanen i.Brevik D.Razansky S.E.Bialkowski Department of Physics Universidade Estadual de MaringáMaringáPRBrazil Faculty of mechanical Engineering University of LjubljanaLjubljanaSlovenia Department of Electronics and Nanoengineering Aalto UniversityAaltoFinland Department of Energy and Process Engineering Norwegian University of Science and TechnologyTrondheimNorway institute for Biomedical Engineering and institute of Pharmacology and Toxicology Faculty of MedicineUniversity of ZurichZurichSwitzerland institute for Biomedical Engineering Department of Information Technology and Electrical EngineeringETH ZurichZurichSwitzerland Department of chemistry and Biochemistry Utah State UniversityLoganUTUSA

Precise control over light-matter interactions is critical for many optical manipulation and material characterization methodologies,further playing a paramount role in a host of nanotechnology ***,the fundamental aspects of interactions between electromagnetic fields and matter have yet to be established unequivocally in terms of an electromagnetic momentum ***,we use tightly focused pulsed laser beams to detect bulk and boundary optical forces in a dielectric *** the optical convoluted signal,we decouple thermal and nonlinear optical effects from the radiation forces using a theoretical interpretation based on the microscopic Ampère force *** is shown,for the first time,that the time-dependent pressure distribution within the fluid chiefly originates from the electrostriction *** results shed light on the contribution of optical forces to the surface displacements observed at the dielectric air-water interfaces,thus shedding light on the long-standing controversy surrounding the basic definition of electromagnetic momentum density in matter.

关键词： dielectric momentum surface

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