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A Seismic Hazard map Based on Geology and Shear-wave Velocity in Rawalpindi–Islamabad,Pakistan

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Acta Geologica Sinica(English Edition) 2021年第2期95卷 659-673页

作者： Sarfraz KHAN muhammad WASEEm m.Asif KHAN National Centre of Excellence in Geology University of Peshawar 25130KPPakistan University of Peshawar 25120 KPPakistan

The‘twin cities’district of Rawalpindi–Islamabad is among the most endangered seismic regions in Pakistan,with the seismic hazard assessed(0.32 g)to intensity IX mmI for a 475-year return period.A seismic hazard map for Rawalpindi–Islamabad is presented herein,based on 85 shear-wave velocity(VS)profiles obtained through geophysical H/V measurements and from the geological map of the *** between the average top thirty-meter shear-wave velocities(VS30)and surficial geological units have been *** peak ground acceleration(PGA)maps for 150,475 and 2475-year return periods were converted into a seismic intensity *** increments for different soils were used to compute PGA values for 150,475 and 2475-year return *** located on softer ground experienced a higher degree of damage from moderate *** to the presence of soft clay or liquefiable soil and lateral spreading,a few locations may be classified as hybrid sites class C and *** map is a critical step in facilitating code-based site classification and seismic design throughout Rawalpindi–*** the seismic hazard map based on seismic intensities is no longer used in engineering geology,it is still important in seismological analysis and for civil protection purposes.

关键词： seismic hazard site classification intensity increment engineering geology Rawalpindi-Islamabad

Nonlinear beam formulation incorporating surface energy and size effect:application in nano-bridges

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Applied mathematics and mechanics(English Edition) 2016年第5期37卷 583-600页

作者： A.KOOCHI H.HOSSEINI-TOUDESHKY m.ABADYAN Department of Aerospace Engineering Amirkabir University of TechnologyTehran 15875-4413Iran mechanical Engineering Group Shahrekord BranchIslamic Azad UniversityShahrekord ***Iran

A nonlinear beam formulation is presented based on the Gurtin-murdoch surface elasticity and the modified couple stress theory. The developed model theoretically takes into account coupled effects of the energy of surface layer and microstructures size- dependency. The mid-plane stretching of a beam is incorporated using von-Karman nonlinear strains. Hamilton＇s principle is used to determine the nonlinear governing equation of motion and the corresponding boundary conditions. As a case study, pull-in instability of an electromechanical nano-bridge structure is studied using the proposed formulation. The nonlinear governing equation is solved by the analytical reduced order method （ROm） as well as the numerical solution. Effects of various parameters including surface layer, size dependency, dispersion forces, and structural damping on the pull- in parameters of the nano-bridges are discussed. Comparison of the results with the literature reveals capability of the present model in demonstrating the impact of nano- scale phenomena on the pull-in threshold of the nano-bridges.

关键词： surface energy size effect nonlinear beam formulation electromechanicalnano-bridge pull-in instability

Physical-Chemical Characterization of Nanodispersed Powders Produced by a Plasma-Chemical Technique

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Plasma Science and Technology 2007年第3期9卷 273-279页

作者： m.GEORGIEVA G.VISSOKOV Iv.GRANCHAROV Department of Technology of Inorganic Substances University of Chemical Technology and Metallurgy8St.Kliment Ohridski Blvd.1756 SofiaBulgaria

This article presents a review on the physical-chemical properties and characteristics of plasma-chemically produced nanodispersed powders （NDP）, such as metals, oxides, nitrides, carbides, and catalysts. The plasma-chemical preparatior~ of the powders was carried out in thermal plasma （TP） created by means of high-current electric arcs, plasma jets, high-frequency （HF） discharges, etc. We also discuss certain properties and characteristics of the NDPs, which are determined largely by the conditions of preparation.

关键词： plasma-chemical treatment nitrides thermodynamic analysis

A discrete model for response estimation of soil-structure systems with embedded foundations

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Earthquake Engineering and Engineering Vibration 2011年第2期10卷 263-276页

作者： P.Khodabakhshi H.Jahankhah m.A.Ghannad Department of Civil Engineering Sharif University of Technology

The need for simplified physical models representing frequency dependent soil impedances has been the motivation behind many researches throughout history. Generally, such models are generated to capture impedance functions in a wide range of excitation frequencies, which leads to relatively complex models. That is while there is just a limited range of frequencies that really influence the response of the structure. Here, a new methodology based on the response-matching concept is proposed, which can lead to the development of simpler discrete models. The idea is then used to upgrade an existing simple model of surface foundations to the case of embedded foundations. The applicability of the model in both frequency domain and time domain analyses of soil-structure systems with embedded foundations is discussed. moreover, the accuracy of the results is compared with another existing discrete model for embedded foundations.

关键词： discrete model embedded foundation spectral matching

Energy transfer in solid-state dye lasers based on methyl methacrylate co-doped with sulforhodamine B and crystal violet

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Chinese Physics B 2013年第11期22卷 319-324页

作者： R.G.Geethu mani m.Basheer Ahamed Department of Physics KCG College of Technology Research Centre Bharathiar University Department of Physics B.S. Abdur Rahman University

Laser action in methyl methacrylate （mmA） co-doped with sulforhodamine B and crystal violet dyes was investi- gated. The dye mixture was incorporated into a solid polymeric matrix and was pumped by a 532-nm Nd：YAG laser. Distributed feedback dye laser （DFDL） action was induced in the dye mixture using a prism arrangement both in the donor and acceptor regions by an energy transfer mechanism. Theoretically, the characteristics of acceptor and donor DFDLs, and the dependence of their pulse widths and output powers on acceptor-donor concentrations and pump power, were studied. Experimentally, the output energy of DFDL was measured at the emission peaks of donor and acceptor dyes for different pump powers and different acceptor-donor concentrations. Tuning of the output wavelength was achieved by varying the period of the gain modulation of the laser medium. The laser wavelength showed continuous tunability from 563 nm to 648 nm.

关键词： sulforhodamine B crystal violet distributed feedback dye laser solid state distributed feedbackdye laser

Optimizing micaceous soil stabilization using response surface method

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Journal of Rock mechanics and Geotechnical Engineering 2021年第1期13卷 212-220页

作者： J.Zhang A.Deng m.Jaksa School of Civil Environmental and Mining EngineeringUniversity of AdelaideAdelaideSA 5000Australia

micaceous soil is a problematic soil due to its low strength and poor *** this context,the performances of micaceous soils were improved by applying a combination of granulated blast furnace slag,fiber and polymer *** dosages examined included 0%e30%mica,3%e15%slag and 0.25%e1.25%fiber by weight,and 0.1e0.5 g/L polymer *** of the combinations were found to increase the material strength and ductility,yet to be *** refine the dosage,response surface method was used to conduct experimental design and develop predictive models for material *** developed models formulate the material strength as a nonlinear function of dosages and,by interrogating it,can optimize additive contents in terms of target *** models were verified through trials and can be used to determine dosages to upscale micaceous soils to field conditions.

关键词： Fiber Polymer Central composite design Unconfined compression strength(UCS) mica

Crystal Growth of[Ca3Al(OH)6·12H2O]2·(SO4)3·2H2O (Ettringite) Studied Under microgravity Conditions

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Journal of Wuhan University of Technology(materials Science) 2020年第5期35卷 893-899页

作者： meier m R LEI L Rinkenburger A Plank J Technische Universitat miinchen Chair for Construction Chemistry85747 GarchingLichtenbergstrafie 4Germany

On parabolic flights,the growth of ettringite,[Ca3Al(OH)6·12H2O]2·(SO4)3·2H2O,a major reaction product of cement with water which forms instantaneously,was crystallized under microgravity conditions and *** the experiments,Ca(OH)2/Al2(SO4)3 solutions were combined and reacted for 10?s,followed by immediate filtration of the suspension and subsequent quenching with *** the ettringite crystals,the size,aspect ratios,quantity and morphology were determined and the results were compared with those from identical experiments performed under terrestric *** microgravity,generally smaller crystals (l-2.9 μm) precipitated in larger amount than under normal gravity (l-3.5 μm).The aspect ratios of the crystals grown under terrestric or microgravity condition were comparable at about *** is assumed that the reason for the smaller ettringite crystals is the absence of convection leading to more initial nuclei,but slower crystal growth which is diffusion ***,no preference relative to the ion transport to the different faces of the crystals *** results contribute to the understanding of the mineralization of inorganic salts under microgravity conditions for which hitherto only a handful of examples were reported.

关键词： crystallization ettringite microgravity morphology nucleation

Solid fraction evolution characteristics of semi-solid A356 alloy and in-situ A356–TiB_2 composites investigated by differential thermal analysis

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International Journal of minerals,metallurgy and materials 2015年第4期22卷 389-394页

作者： S.Deepak Kumar A.mandal m.Chakraborty School of mechanical Sciences Indian Institute of Technology Bhubaneswar School of minerals Metallurgical and Materials Engineering Indian Institute of Technology Bhubaneswar

The key factor in semi-solid metal processing is the solid fraction at the forming temperature because it affects the microstructure and mechanical properties of the thixoformed components. Though an enormous amount of data exists on the solid fraction-temperature re- lationship in A356 alloy, information regarding the solid fraction evolution characteristics of A356-TiB2 composites is scarce. The present article establishes the temperature-solid fraction correlation in A356 alloy and A356-xTiB2 （x = 2.5wt% and 5wt%） composites using dif- ferential thermal analysis （DTA）. The DTA results indicate that the solidification characteristics of the composites exhibited a variation of 2℃ and 3℃ in liquidus temperatures and a variation of 3℃ and 5℃ in solidus temperatures with respect to the base alloy. moreover, the eutectic growth temperature and the solid fraction（fs） vs. temperature characteristics of the composites were found to be higher than those of the base alloy. The investigation revealed that in-situ formed TiB2 particles in the molten metal introduced more nucleation sites and reduced undercooling.

关键词： particle reinforced composites aluminum alloys titanium boride casting solid fraction differential thermal analysis

Propagation of an electromagnetic soliton in an anisotropic biquadratic ferromagnetic medium

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Chinese Physics B 2013年第3期22卷 275-281页

作者： L.Kavitha m.Saravanan D.Gopi Department of Physics Periyar University The Abdus Salam International Centre for Theoretical Physics TriesteItaly Center for Nanoscience and Nanotechnology Periyar University Department of Chemistry Periyar University

Information storage technology based on anisotropic ferromagnets with sufficiently high magneto-optical effects has received much attention in recent ***-optical recording combines the merits of magnetic and optical *** investigate the magneto-optical effects on a biquadratic ferromagnet and show that the dynamics of the system are governed by a perturbed nonlinear Schro¨dinger *** evolutions of amplitude and velocity of the soliton are found to be time independent,thereby admitting the lossless propagation of the electromagnetic soliton in the medium,which may have potential applications in soliton based optical communication *** also exploit the role of perturbation,which has a significant impact on the propagation of an electromagnetic soliton.

关键词： solitons classical spin models maxwell equations nonlinear dynamics