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Nuclear structure and decay modes of Ra isotopes within an axially deformed relativistic mean field model

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Chinese Physics C 2018年第8期42卷 121-129页

作者： Rashmirekha swain s.K.Patra b.b.sahu school of Applied sciences KIIT Deemed to be UniversityBhubaneswar-751024OdishaIndia Institute of Physics Bhubaneswar-751005India

We examine the structural properties and half-life decay of Ra isotopes within the axially deformed Relativistic Mean-Field（RMF）theory with NL3 force *** work out the binding energy（bE）,RMs radii,two-neutron separation energies（s（2n））,and some other *** results are in good agreement with the finite-range droplet model（FRDM）and experimental *** the possibility of neutron magic number,theα-decay and cluster decay half-lives of Ra isotopes are calculated systematically using the Q-values obtained from the RMF *** decay half-life calculations are carried out by taking three different empirical *** calculated decay half-lives are found to be highly sensitive to the choice of *** shell or sub-shell closures are found at daughter nuclei with N=128 and N=126 when alpha and 8be,12C,18O respectively are emitted from Ra *** the cluster radioactivity is affected by the shell closure of parent and daughter,a long half-life indicates the stability of the parent,and a small parent half-life indicates that the shell stability of the daughter against decay.

关键词： relativistic mean field nuclear bulk properties alpha and cluster decay half-life

sIMPLE COMPUTING OF THE CUsTOMER LIFETIME VALUE:A FIXED LOCAL-OPTIMAL POLICY APPROACH

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Journal of systems science and systems Engineering 2014年第4期23卷 439-459页

作者： Julio b.Clempner Alexander s.Poznyak Center for Economics Management and Social Research Department of Control Automatics Center for Research and Advanced studies

In this paper,we present a new method for finding a fixed local-optimal policy for computing the customer lifetime *** method is developed for a class of ergodic controllable finite Markov *** propose an approach based on a non-converging state-value function that fluctuates（increases and decreases） between states of the dynamic *** prove that it is possible to represent that function in a recursive format using a one-step-ahead fixed-optimal ***,we provide an analytical formula for the numerical realization of the fixed local-optimal *** also present a second approach based on linear programming,to solve the same problem,that implement the c-variable method for making the problem computationally *** the end,we show that these two approaches are related：after a finite number of iterations our proposed approach converges to same result as the linear programming *** also present a non-traditional approach for ergodicity *** validity of the proposed methods is successfully demonstrated theoretically and,by simulated credit-card marketing experiments computing the customer lifetime value for both an optimization and a game theory approach.

关键词： Customer lifetime value optimization optimal policy method linear programming ergodic controllable Markov chains asynchronous games

seismic analysis of diagrid structural frames with shear-link fuse devices

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Earthquake Engineering and Engineering Vibration 2013年第3期12卷 463-472页

作者： Nasim s. Moghaddasi b. Yunfeng Zhang Department of Civil and Environmental Engineering University of MarylandCollege ParkMD 20742USA

This paper presents a new concept for enhancing the seismic ductility and damping capacity of diagrid structural frames by using shear-link fuse devices and its seismic performance is assessed through nonlinear static and dynamic analysis. The architectural elegancy of the diagrid structure attributed to its triangular leaning member configuration and high structural redundancy make this system a desirable choice for tall building design. However, forming a stable energy dissipation mechanism in diagrid framing remains to be investigated to expand its use in regions with high seismicity. To address this issue, a diagrid framing design is proposed here which provides a competitive design option in highly seismic regions through its increased ductility and improved energy dissipation capacity provided by replaceable shear links interconnecting the diagonal members at their *** structural characteristics and seismic behavior （capacity, stiffness, energy dissipation, ductility） of the diagrid structural frame are demonstrated with a 21-story building diagrid frame subjected to nonlinear static and dynamic analysis. The findings from the nonfinear time history analysis verify that satisfactory seismic performance can be achieved by the proposed diagrid frame subjected to design basis earthquakes in California. In particular, one appealing feature of the proposed diagrid building is its reduced residual displacement after strong earthquakes.

关键词： diagrid structure nonlinear analysis seismic behavior shear link steel structure

Phase evolution and mechanical properties of novel nanocrystalline Y_(2)(TiZrHfMoV)_(2)O_(7) high entropy pyrochlore

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Journal of Materials science & Technology 2021年第23期82卷 214-226页

作者： G.Karthick Lavanya Raman b.s.Murty Department of Metallurgical and Materials Engineering Indian Institute of Technology MadrasChennai600036India Indian Institute of Technology Hyderabad Kandi502285India

High entropy pyrochlores(HEP)are potential candidates as dispersoids in the oxide dispersed strengthened steels or alloys,which can be used in nuclear reactors and supercritical *** the first time,HEP oxides Y_(2)(TiZrHfMoV)_(2)O_(7) were synthesized with Y_(2)Ti_(2)O_(7) as a base structure with the b site(Ti)substituted with five cations through reverse co-precipitation technique in the nanocrystalline form at lowest synthesis *** synthesis parameters for Y_(2)(TiZrHfMoV)_(2)O_(7)(5C)and other derived compositions(five compositions of four cationic systems with each cation eliminated at b site from 5 C)are optimised to obtain lower crystallite and particle sizes.5C has a smaller crystallite size(27 nm)than other single-phase *** cation’s influence,oxidation state,and oxygen vacancy in the phase formation were analysed through *** single-phase HEPs are consolidated through spark plasma sintering.Y_(2)(TiZrHfMo)_(2)O_(7)(4 C-V)shows the highest hardness among the compositions reported so far due to its finer grain size,and Y_(2)(TiHfMoV)_(2)O_(7)(4 C-Zr)has a higher Young’s modulus compared to other single-phase composition due to its higher degree of order in the structure.

关键词： High entropy pyrochlores Reverse co-precipitation b site substitution Hardness Young’s modulus

Heat transfer analysis of MHD and electroosmotic flow of non-Newtonian fluid in a rotating microfluidic channel:an exact solution

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Applied Mathematics and Mechanics(English Edition) 2021年第7期42卷 1047-1062页

作者： T.sIVA s.JANGILI b.KUMbHAKAR Department of Mathematics National Institute of Technology MeghalayaShillong 793003India Department of Mathematics National Institute of Technology WarangalTelangana 506004India

The heat transfer of the combined magnetohydrodynamic(MHD)and electroosmotic flow(EOF)of non-Newtonian fluid in a rotating microchannel is analyzed.A couple stress fluid model is scrutinized to simulate the rheological characteristics of the *** exact solution for the energy transport equation is ***,this solution is utilized to obtain the flow velocity and volume flow rates within the flow domain under appropriate boundary *** obtained analytical solution results are compared with the previous data in the literature,and good agreement is obtained.A detailed parametric study of the effects of several factors,e.g.,the rotational Reynolds number,the Joule heating parameter,the couple stress parameter,the Hartmann number,and the buoyancy parameter,on the flow velocities and temperature is *** is unveiled that the elevation in a couple stress parameter enhances the EOF velocity in the axial direction.

关键词： microfluidic electric double layer(EDL) electroosmotic flow(EOF) magnetohydrodynamic(MHD) couple stress fluid

study of hybrid nanofluid flow in a stationary cone-disk system with temperature-dependent fluid properties

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Applied Mathematics and Mechanics(English Edition) 2024年第4期45卷 677-694页

作者： A.s.JOHN b.MAHANTHEsH G.LORENZINI Center for Mathematical Needs Department of MathematicsCHRIST(Deemed to be University)Karnataka 560029India school of Mathematical and statistical sciences The University of Texas Rio Grande ValleyTexas 78539U.S.A. Department of Engineering and Architecture University of ParmaParma 43124Italy

Cone-disk systems find frequent use such as conical diffusers,medical devices,various rheometric,and viscosimetry *** this study,we investigate the three-dimensional flow of a water-based Ag-Mg O hybrid nanofluid in a static cone-disk system while considering temperature-dependent fluid *** the variable fluid properties affect the dynamics and heat transfer features is studied by Reynolds's linearized model for variable viscosity and Chiam's model for variable thermal *** single-phase nanofluid model is utilized to describe convective heat transfer in hybrid nanofluids,incorporating the experimental *** model is developed as a coupled system of convective-diffusion equations,encompassing the conservation of momentum and the conservation of thermal energy,in conjunction with an incompressibility condition.A self-similar model is developed by the Lie-group scaling transformations,and the subsequent self-similar equations are then solved *** influence of variable fluid parameters on both swirling and non-swirling flow cases is ***,the Nusselt number for the disk surface is *** is found that an increase in the temperature-dependent viscosity parameter enhances heat transfer characteristics in the static cone-disk system,while the thermal conductivity parameter has the opposite effect.

关键词： hybrid nanofluid cone-disk system laminar flow variable fluid property Nusselt number

Investigation into machining performance of microstructurally engineered in-situ particle reinforced magnesium matrix composite

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Journal of Magnesium and Alloys 2023年第3期11卷 916-935页

作者： s.K.sahoo b.N.sahoo s.K.Panigrahi Department of Mechanical Engineering Indian Institute of Technology MadrasChennai 600036India Applied Magnesium Research Group Center of Excellence in Materials and Manufacturing for Futuristic MobilityIndian Institute of Technology MadrasChennai 600036India Department of Mechanical Engineering Sardar Vallabhbhai National Institute of TechnologySurat 395007India

Magnesium and magnesium in-situ composites have significant potential in the application of design and manufacturing for automotive and aerospace industries because of their high specific strength and reduced fuel *** there are many challenges for machining of Mg based alloys and composites because of the high tendency of fire and *** challenges can be minimized through microstructural *** this present study,the machining performances of AZ91 Mg alloy and in-situ hybrid TiC+Tib_(2)reinforced AZ91 metal matrix composite was *** effectβ-Mg_(17)Al_(12)phases and grain refinement with and without in-situ particles on machinability were studied through microstructural engineering via aging and friction stir *** end milling operation was carried out at different cutting speeds ranging from 25 mm/min to 90 mm/min under dry environment by using an AlTiN-coated tungsten carbide *** optimum cutting speed for machining was found to be 75 mm/min based on the surface roughness values of all conditioned *** base material with dendritic microstructure was found to have poor machinability in terms of inadequate surface finish and edge-burrs *** combined effect of in-situ TiC+Tib_(2)particles addition and grain refinement enhanced the machining performance of the material with superior surface finish,negligible edge-burr formation and better tool wear *** influence of in-situ TiC+Tib_(2)particles,β-Mg_(17)Al_(12)phases and grain refinement on machining characteristics are explained based on the tool wear mechanisms,chip behavior and machining induced affected zone.

关键词： Magnesium In-situ composite End-milling Tool wear Chip morphology

Extraction,Utilization Pattern and Prioritization of Fuel Resources for Conservation in Manali Wildlife sanctuary,Northwestern Himalaya

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Journal of Mountain science 2012年第4期9卷 580-588页

作者： Man s.RANA sakshi b.RANA s.s.sAMANT Department of Plant sciences Government CollegeBanjar-Kullu175123Himachal PradeshIndia Department of Plant sciences Government CollegeKullu175101Himachal PradeshIndia G.b.Pant Institute of Himalayan Environment&Development Himachal UnitMohal-Kullu175126Himachal PradeshIndia

Fuelwood is the main source of the energy in mountainous ***,annual wood consumption is very *** on fuelwood resources,and their extraction and availability is very ***,present study was carried out to study the diversity of fuelwood species,annual collection,preference and availability of fuel species in the *** four species(25 trees and 9 shrubs) were extracted for fuel by the *** collection and species preference was highest for Picea smithiana,Cedrus deodara,Indigofera heterantha,Pinus wallchiana and sorbaria tomentosa,*** use index indicating use pressure was highest for ***,***,*** and Abies pindrow,*** native species,some non-native horticultural and agroforestry species such as Malus pumila,***,Celtis australis,*** also being used as *** species showed their availability in eight forest types whereas,population and regeneration status was ***,immediate actions are suggested to sustain current and future demand of *** afforestation of degraded,uncultivated and marginal lands through high quality and preferred fuel species might reduce pressure on wild and selective species.

关键词： Fuelwood Resource Use Index Communities Conservation

Positron Energy Levels in Cd-based semiconductors

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Communications in Theoretical Physics 2013年第6期59卷 756-762页

作者： b.Abbar s.Mécabih s.Amari N.benosman b.bouhafs Laboratoire de Modélisation et de simulation en sciences des Département de Physique Université Djillali Liabès

Using the full potential linearized augmented plane wave FP-LAPW method within local density ap-proximation LDA, we have studied positron diffusion and surface emission in Cd-based semiconductors. This requires the calculation of electron and positron band structures. In the absence of experimental and theoretical data for CdX (X=s,se,Te) we have treated the si, which has been studied by several authors, as a test case. Predictive results on positron effective masses, deformation potentials, positron work functions, diffusion constants and positron mobilities are presented for CdX (X=s, se, Te). Our calculated data for si are compared with experimental and recent theoretical results.

关键词： DFT FP-LAPW semiconductors positron diffusion