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Etchability of Latent Fission Fragment Tracks in CR-39

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Chinese Physics Letters 2007年第11期24卷 3107-3110页

作者： Mukhtar Ahmed rana Physics Division Directorate of Science PINSTECH P.O. Nilore Islamabad Pakistan

We report the chemical etching behaviour of the CR-39 polymer detector exposed to fission fragments of 252Cf describing etchability of latent tracks, which are like nanocylinders. The fission fragment exposed detectors were etched in 1-7 N NaOH water solutions at temperatures 50-80℃ for 45 min in the case of track length and 180 min in the case of track diameter measurements. The reduced etch rate S （called here etchability） is determined using experimental results for all etching conditions and the etching conditions with the highest reduced etch are obtained. Physics and energetics of bulk and track etching are discussed. Possible effects causing spurious changes in determination of activation energy of etching are investigated.

关键词： coated conductor buffer layer self-epitaxy CeO2

Planar Channelling Criticalities of MeV Protons in Si Crystal： Simulations, Evaluation and Applications

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Chinese Physics Letters 2008年第10期25卷 3724-3727页

作者： Mukhtar Ahmed rana Methodology Applications Initiative Physics Division PINSTECH Post Office Nilore Islamabad Pakistan

We reports a phase-space structure of MeV proton beam planar channelled along {110} planes in Si crystal using simulation results with the help of a computer code FLUX. The aim is to understand channelling conditions suitable for disorder measurement in crystals. Phase-space distribution of a planar channelled proton beam evolutes in a systematic fashion when it travels into the crystal. Planar channelled beam oscillates between phase-like and space-like conditions in which a part of the beam becomes under phase and space criticalities. These criticality conditions in planar channelling are analysed, explained and discussed with the perspective of defect measurement in crystals.

关键词： the power-law exponents precipitation durative abrupt precipitation change

Formation of Charged Particle Tracks in Solids

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Chinese Physics Letters 2006年第6期23卷 1448-1451页

作者： Mukhtar A. rana Physics Research Division PINSTECH PO Nilore Islamabad Pakistan

A criterion for formation of etchable tracks in solids is suggested using the well-known concepts of ionization and thermal spikes, diffusion process with useful and justified assumptions, and present or published experimental and theoretical investigations on the same subject. The suggested criterion is useful for a wide spectrum of researchers including development and applications of track recording materials, ions implantation, sputtering and other areas, which include interactions of charged particles with solids.

关键词： RADIATION-DAMAGE ACTIVATION-ENERGY AUGER ELECTRONS CR-39 DETECTORS

Radiation-Induced Nano-Explosions at the Solid Surface: Near Surface Radiation Damage in CR-39 Polymer

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Chinese Physics Letters 2011年第8期28卷 83-86页

作者： Mukhtar Ahmed rana Physics Division Pakistan Institute of Nuclear Science and Technology(PINSTECH)P.O.NiloreIslamabadPakistan

New measurements of fission fragment and alpha particle induced surface damage in the most sensitive and commonly used nuclear track detector CR-39 are presented *** designed and optimized exposure and chemical etching experiments are employed to unfold the structure of radiation induced surface damage(RISD).Delay in the startup of the chemical etching of latent tracks or surface radiation damage is measured and is found to contain important information about the structure of the surface *** atomic scale pictures of RISD and its chemical etching are developed in an empirical *** model and experimental findings coherently compose a realistic picture of early or femtosecond evolution of RISD.

关键词： coherent finding damage

Seismic demand of plan-asymmetric structures:a revisit

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Earthquake Engineering and Engineering Vibration 2013年第1期12卷 99-117页

作者： rana Roy Suvonkar Chakroborty Department of Aerospace Engineering & Applied Mechanics Bengal Engineering and Science UniversityShibpurIndia SMS India Pvt.Ltd. SMS GroupIndia

In view of the recognition of the importance of the interdependent behavior of strength and stiffness of walltype structural elements,the seismic demand of plan-asymmetric systems is *** strength distribution strategies,i.e.,＇Center of Strength-Center of Mass（CV-CM） coinciding＇ and ＇Balanced Center of Strength-Center of Resistance（CVCR）＇ are *** charts for the seismic demand of classical uni-directionally and bi-directionally asymmetric systems are developed in a simple unified format.A conceptual framework is also outlined to conveniently apply the design *** are included to explain the use of the current recommendations in practical *** study also highlights the relative performance of ＇CV-CM coinciding＇ and ＇Balanced CV-CR＇ criteria.

关键词： asymmetry seismic strength dependent stiffness design chart

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Corrosion by a Heavy Metal Oxide Glass

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Journal of Materials Science & Technology 2005年第2期21卷 243-245页

作者： B.B.rana Department of Engineering Materials University of Sheffield Sheffield S1 4DU UK PCSIR Laboratories Complex LahorePakistan

Melts of lead bismuth gallate compositions are highly corrosive and attack on crucibles of different materials. In the present study, corrosion by a base glass (50PbO-30Bi2O3-20Ga2O3 in mole fraction) melted using different crucibles and the effect on UV-VIS and IR edges were studied. By melting the base glass in platinum/2% rhodium, gold zirconia and alumina crucibles showed less effect on the IR edge and therefore shifted the infrared edge to longer wavelength, whereas silica crucible contaminated the glass, causing a severe deterioration in the infrared and hence shifted infrared edge to much shorter wavelength. In the UV-VIS region, base glass melted in platinum/2% rhodium crucible shifted the edge to the longest wavelength whereas silica crucible shifted the edge to shorter wavelength. The contaminants from gold, zirconia and alumina crucibles caused the UV-VIS edge of the base glass to lie between the two extremes of Pt/2% Rh and SiO2 crucibles. The glasses melted in above mentioned crucibles were also characterized with inductively coupled plasma spectroscopy (ICP) analysis to measure the level of contamination from the crucibles. Depending upon crucible used, the colors of glasses obtained ranged from red to yellow.

关键词： Oxide glass Corrosion Crucible

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Synthesis of PbS-K2La2Ti3O10 composite and its photocatalytic activity for hydrogen production

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Progress in Natural Science:Materials International 2012年第2期22卷 120-125页

作者： Dipak rana Department of Chemical and Biological Engineering University of OttawaOttawaCanada K1N 6N5

Photocatalyst,lead sulfide(PbS)-intercalated layer perovskite-type compound(K2La2Ti3O10),was synthesized via ion-exchange reaction,butylamine pillaring and sulfuration processes under the assistance of the microwave *** structure of the photocatalysts was determined by means of powder X-ray diffraction,scanning electron microscope,ultraviolet-visible diffuse reflection spectra and photoluminescence *** the photocatalytic activity of the composite compound for hydrogen production was also *** experimental results showed that the intercalation of PbS in the layered space of K2La2Ti3O10 greatly improved the absorption edge and the photocatalytic *** production of the PbS-K2La2Ti3O10 was 127.19 mmol/(g cat)after 3 h irradiation of ultraviolet light.

关键词： K2La2Ti3O10 Microwave irradiation PbS Intercalation Hydrogen production Catalytic performance

Heat transfer optimization and rheological features of Buongiorno nanofluid in a convectively heated inclined annulus with nonlinear thermal radiation

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Propulsion and Power Research 2023年第4期12卷 539-555页

作者： Puneet rana School of Mathematical Sciences College of ScienceMathematics and TechnologyWenzhou Kean UniversityWenzhou 325060China

The theoretical analysis of the mixed convective Buongiorno nanofluid flow in an inclined annular microchannel with convectively heated walls subjected to the effects of nonlinear thermal radiation,exponential heat source(EHS),thermal dependent heat source(THS)is carried *** description of the Buongiorno nanofluid is implemented to analyze the Brownian diffusion and thermo-migration *** general boundary conditions for the velocity,thermal,and nanoparticle volume fraction(NVF)are *** solutions for fully developed governing equations are obtained using bvp5c solver and verified with *** optimization of heat transport rates is made by using the Box-Behnken designbased response surface *** is found that the Lorentz force and the inclination angle of the annulus significantly affect the rheological characteristics of the *** increase thermal energy in the system through Brownian diffusion and thermophoresis,resulting in increased temperature *** heat sources would serve as an important tool for modulating the thermal field in microchannel,as they are directly *** low-level values of the thermal Biot number,the exponential heat source,and the thermal radiation parameter,it is possible to attain the maximum Nusselt number on both walls of the annulus.

关键词： Buongiorno model Convective boundary conditions Exponential spacerelated heat source Nanofluid Annulus Response surface methodology

A compound spike model for formation of nuclear tracks in solids

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Nuclear Science and Techniques 2007年第6期18卷 349-353页

作者： Mukhtar Ahmed rana Physics Division Directorate of SciencePINSTECHP.O.NiloreIslamabadPakistan

Formation of nuclear tracks in solids has been described as a thermal spike as well as a Coulomb explo- sion ***,formation of nuclear tracks is described as a compound spike including partial roles of both thermal and Coulomb explosion spikes in track *** roles of both spikes depend on atomic and electronic structure of a track detector and deposited energy density in the track detector by the incident charged ***- havior of the cylindrical zone along the path of the incident particle is described mathematically in terms of bulk and individual atomic flow or *** structure of the latent nuclear tracks is described and conditions of con- tinuity and discontinuity of latent tracks are evaluated and *** paper includes mathematical description, analysis and evaluation of the nuclear track formation issue in the light of published experimental and theoretical re- sults,which are useful for users of nuclear track detection technique and researchers involved in ion beam induced materials modification and ions implantation in semiconductors.

关键词：核子轨道探测技术晶体固态径迹探测探测方法

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