Studies of ï°g9/2+ isomers in odd 67-79As nuclei by deep-inelastic collisions

In this paper, we report systematic studies of single particle pg9/2+ isomers in odd 67-79As nuclei. We have calculated the energies of projectile-like fragments of odd 67-79As in 76Ge (635 MeV) + 198Pt reactions. The theoretical calculations of projectile like fragments (PLFs) energies are compared with the experimental values. The mean lives, reduced transition probabilities, width of isomeric levels, and Weisskopf hindrance factors in odd 67-79As nuclei are calculated. The excitation levels of 9/2+ and 5/2- state as a function of mass number from odd 67As to 79As nuclei indicate maximum deformation at N=42. The systematic reduced transition probabilities B(M2) of odd 67-79As nuclei are also investigated. The angular distributions of fragments energies of 79As and its counterpart as a function of scattering angles are investigated

Effects of chemical reactions on unsteady free convective and mass transfer flow from a vertical cone with heat generation/absorption in the presence of VWT/VWC

A mathematical model for the effects of chemical reaction and heat generation/absorption on unsteady laminar free convective flow with heat and mass transfer over an incompressible viscous fluid past a vertical permeable cone with nonuniform surface temperature T w '(x) = T ∞' + a x n and concentration C w '(x) = C ∞' + b x m is considered here. The dimensionless governing boundary layer equations of the flow that are transient, coupled, and nonlinear partial differential equations are solved by an efficient, accurate, and unconditionally stable finite difference scheme of Crank-Nicholson type. The velocity, temperature, and concentration profiles have been studied for various parameters, namely, chemical reaction parameter, the heat generation and absorption parameter Δ, Schmidt number Sc, Prandtl number Pr, buoyancy ratio parameter N, surface temperature power law exponent n, and surface concentration power law exponent m. The local as well as average skin friction, Nusselt number, and Sherwood number are discussed and analyzed graphically. The present results are compared with available results in open literature and are found to be in excellent agreemen

Free vibration of symmetric angly-plane layered truncated conical shells under classical theory

Truncated conical shell finds wide ranging of engineering applications. They are used in space crafts, robots, shelters, domes, tanks, nozzles and in machinery devices. Thus, the study of their vibrational characteristics has long been of interest for the designers. The use of the lamination for the structures leads to design with the maximum reliability and minimum weight. Moreover, the study of free vibration of laminated conical shells has been treated by a number of researchers. Irie et al. (1982) studied free vibration of conical shells with variable thickness using Rayleigh-Ritz method of solution. Wu and Wu (2000) provided 3D elasticity solutions for the free vibration analysis of laminated conical shells by an asymptotic approach. Wu and Lee (2001) studied the natural frequencies of laminated conical shells with variable stiffness using the differential quadrature method under first-order shear deformation theory (FSDT). Tripathi et al. (2007) studied the free vibration of composite conical shells with random material properties of the finite element method. Civalek (2007) used the Discrete Singular Convolution (DSC) to investigate the frequency response of orthotropic conical and cylindrical shells. Sofiyez et al. (2009) studied the vibrations of orthotropic non-homogeneous conical shells with free boundary conditions. Ghasemi et al. (2012) presented their study of free vibration of composite conical shells which was investigated under various boundary conditions using the solution of beam function and Galerkin method. Viswanathan et al. (2007, 2011) studied free vibration of laminated cross-ply plates, including shear deformation, symmetric angle-ply laminated cylindrical shells of variable thickness with shear deformation theory using the spline collocation method. In the present work, free vibration of symmetric angle-ply laminated truncated conical shells is analyzed and displacement functions are approximated using cubic and quantic spline and collocation procedure is applied to obtain a set of field equations. The field equations along with the equations of boundary conditions yield a system of homogeneous simultaneous algebraic equations on the assumed spline coefficients which resulting to the generalized eigenvalue problem. This eigenvalue problem is solved using eigensolution technique to get as many eigenfrequencies as required. The effect of circumferential mode number, length ratio, cone angle, ply angles and number of layers under two boundary conditions on the frequency parameter is studied for three- and five- layered conical shells consisting of two types of layered materials

Numerical simulation of welding residual stress distribution on T-joint fillet structure

Fillet welding is widely used in the assembly of ships and offshore structures. The T-joint configuration is fre-quently reported to experience fatigue damage when a marine structure meets extreme loads such as storm loads. Fatigue damage is affected by the magnitude of residual stresses on the weld. Recently, many shipping registers and design guides have required that the fatigue strength assessment procedure of seagoing structures under wave-induced random loading and storm loading be compensated based on the effect of residual stresses. We propose a computational procedure to analyze the residual stresses in a T-joint. Residual stresses are measured by the X-ray diffraction (XRD) method, and a 3-D finite element analysis (FEA) is performed to obtain the residual stress pro-file in the T-joint. The proposed finite element model is validated by comparing experiments with computational results, and the characteristics of the residual stresses in the T-joint are discussed

Effects of g-jitter combined with heat and mass transfer by mixed convection mhd flow of a second grade fluid in a porous medium

The effects of g-jitter induced and combined with heat and mass transfer by mixed convection in microgravity situation on MHD flow second grade fluid in porous space is investigated for a particular system. This system consists of two heated vertical parallel infinite flat plates held at constant but different temperatures and concentrations. By using modified Darcy’s law, the equations governing the flow are modelled. These equations are solved analytically for the induced velocity, temperature and concentration distributions. Similar result in the relevant literature relating to Newtonian fluid is also obtained as a special case of the present solution. Finally particular attention is given to the graphical results for the velocity profiles of the oscillating flow in the channel. The analysis on the variations of embedded flow parameters in the solution expressions are presented and discussed

Effect of variable fluid properties on natural convection of nanofluids in a cavity with linearly varying wall temperature

The present study analyzed convective heat transfer and fluid flow characteristics of nanofluid in a two-dimensional square cavity under different combinations of thermophysical models of nanofluids. The right vertical wall temperature is varying linearly with height and the left wall is maintained at low temperature whereas the horizontal walls are adiabatic. Finite volume method is used to solve the governing equations. Two models are considered to calculate the effective thermal conductivity of the nanofluid and four models are considered to calculate the effective viscosity of the nanofluid. Numerical solutions are carried out for different combinations of effective viscosity and effective thermal conductivity models with different volume fractions of nanoparticles and Rayleigh numbers. It is found that the heat transfer rate increases for Models M1 and M3 on increasing the volume fraction of the nanofluid, whereas heat transfer rate decreases for Model M4 on increasing the volume fraction of the nanoparticle. The difference among the effective dynamic viscosity models of nanofluid plays an important role here such that the average Nusselt number demonstrates an increasing or decreasing trend with the concentration of nanoparticle

Free vibration of symmetric angle-ply laminated circular cylindrical shells

Free vibration of symmetric angle-ply laminated circular cylindrical shells is studied using Spline approximation. The equations of motions in longitudinal, circumferential and transverse displacement components, are derived using Love's first approximation theory. The coupled differential equations are solved using Spline approximation to obtain the generalized eigenvalue problem. Parametric studies are performed to analyse the frequency response of the shell with reference to the material properties, number of layers, ply orientation, length and circumferential node number and different boundary conditions

Free vibration of angle-ply conical shells with linear thickness variation

This paper aims to study the effect of arbitrarily linearly varying thickness in the axial direction and edge conditions on the vibration characteristics of shear deformable conical shells. The application of spline function technique for predicting the free vibration of composite laminated conical shells is also investigated. The solutions of displacement functions are assumed in a separable form to obtain a system of coupled differential equations in terms displacement and rotational functions and these displacements and rotational functions are approximated by cubic spline. A generalized eigenvalue problem is obtained and solved numerically for an eigen frequency parameter and an associated eigenvector of spline coefficients. The effect of cone angle, aspect ratio, thickness variation, number of lay ups, stacking sequence, materials used on the stability of conical shells are also discussed. New results presented may be fruitful for the related fields

Comparative study of free vibration of anti-symmetric angle-ply laminated plates

In this study free vibrations of anti-symmetric angle-ply composite plates including shear deformation under clamped-clamped boundary conditions are presented. Two types of numerical methods are adopted to analyze the problem. The spline and radial basis functions base mesh free scheme are applied simultaneously to approximate the displacement and rotational functions. Comparative studies have been made for analyzing the frequency parameters with respect to the material properties, number of layers, fiber orientations, side-to-thickness ratio and aspect ratio. The results are depicted in terms of tables and graphs

Free vibration of symmetric angle ply truncated conical shells under different boundary conditions using spline method

Free vibration of symmetric angle-ply laminated truncated conical shell is analyzed to determine the effects of frequency parameter and angular frequencies under different boundary condition, ply angles, different material properties and other parameters. The governing equations of motion for truncated conical shell are obtained in terms of displacement functions. The displacement functions are approximated by cubic and quintic splines resulting into a generalized eigenvalue problem. The parametric studies have been made and discusse