Some Finiteness Results for Local Cohomology Modules with Respect to a Pair of Ideals

Mathematical Notes - Suppose that $$R$$ is a commutative Noetherian ring with identity, $$I$$ , $$J$$ are ideals of $$R$$ , and let $$M$$ be a finitely generated $$R$$ -module. Let $$H^i_{I,J}(-)$$...     

Analysis of post buckling behavior of circular plates with non-concentric hole using the Rayleigh–Ritz method

This study is conducted to determine the post buckling behavior of circular homogenous plates with non-concentric hole subjected to uniform radial loading using Rayleigh–Ritz method. In order to implement the method, a computer program has been developed and several numerical examples for different boundary conditions are presented to illustrate the scope and efficacy of the procedure. The integration is carried out in natural coordinates through a proper transformation. Consequently, the displacement fields respect to natural coordinates are expressed using the Hierarchical, Hermitian and Fourier series shape functions for interpolating the out-of-plane displacement field and Fourier series and Hierarchical, Lagrange shape functions for interpolating the in-plane displacement field of plate. The Kirchhoff theory is used to formulate the problem in buckling condition. Due to the asymmetry in geometry, the in-plane solution is required to find the stress distribution. Finally, the problem is formulated in post buckling condition using Von-Karman non-linear theory, and a proper Hookean displacement field is presented to analyze the post buckling behavior.     

Modeling semiconductor devices by using Neuro Space Mapping

In this paper a new method for modeling semiconductor devices by use of the drift-diffusion (DD) model and neural networks is presented. Unlike the hydrodynamic (HD) model which is complicated, time consuming with high processing cost, the proposed method has lower complexity and lower simulation time. In this method the RBF neural network has been used for correcting parameters in the drift-diffusion model. Therefore solving approximate model (DD) causes to obtain accurate response. The proposed method is first applied to a silicon n-i-n diode in one dimension, and then to a silicon thin-film MOSFET in two-dimensions, both for interpolation and extrapolation. The obtained results for basic variables, i.e., electron and potential distribution for different voltages, confirm the high efficiency of the proposed method.     

Direct contact heat transfer between two immiscible liquids flowing in a horizontal concentric annulus

Direct contact heat transfer between water and a heat transfer oil was investigated under non-boiling conditions in co-current turbulent flow through a horizontal concentric annulus. The ratio of the inner pipe diameter to the outer pipe diameter (aspect ratio) κ = 0.730−0.816; total liquid velocity (mixture velocity) V_T = 0.42−1.1 m/s; inlet oil temperature T_oi = 38−94°C; oil volume fraction in the flowing mixture φ_o = 0.25−0.75 were varied and their effects on the overall volumetric heat transfer coefficient U_v were determined at constant interfacial tension of 48 dynes/cm.

It was found that, in each concentric pipe set, the overall volumetric heat transfer coefficient increased with increasing dispersed phase volume fraction at each constant mixture velocity and reached a maximum at around φ_o = φ_w ≈ 0.5. The maximum U_v values increased with increasing total liquid velocity and decreasing aspect ratio of the annulus. The volumetric heat transfer coefficient was also found to increase with increasing inlet oil temperature and increasing total liquid velocity but to decrease with length along the test section keeping all other parameters constant. Empirical expressions for the volumetric heat transfer coefficient were obtained within the ranges of the experimental parameters.     

Dispersing behavior of recycled rubber particles

The hydrophobic nature of recycled rubber particles presently limits their use only in non-aqueous media. Recycled rubber particles were chemically modified by preparation of amphiphilic semi-interpenetrating polymer networks using poly(acrylic acid) as the hydrophilic polymer. The resulting composite particles are water dispersible and suitable for various aqueous media applications.