The Public Authority for Applied Education and Training

Kuwait

The Public Authority for Applied Education and Training

Kuwait
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Alherz F.,Aston University | Alherz M.,Trinity College Dublin | Almusawi H.,The Public Authority for Applied Education and Training
Schizophrenia Research: Cognition | Year: 2017

This review investigates the association between N-methyl-D-Aspartate receptor (NMDAR) hypofunction and somatostatin-expressing GABAergic interneurons (SST +) and how it contributes to the cognitive deficits observed in schizophrenia (SZ). This is based on evidence that NMDAR antagonists caused symptoms resembling SZ in healthy individuals. NMDAR hypofunction in GABAergic interneurons results in the modulation of the cortical network oscillation, particularly in the gamma range (30–80 Hz). These gamma-band oscillation (GBO) abnormalities were found to lead to the cognitive deficits observed in the disorder. Postmortem mRNA studies have shown that SST decreased more significantly than any other biomarker in schizophrenic subjects. The functional role of Somatostatin (SST) in the aetiology of SZ can be studied through its receptors. Genetic knockout studies in animal models in Huntington's disease (HD) have shown that a specific SST receptor, SSTR2, is increased along with the increased NMDAR activity, with opposing patterns observed in SZ. A direct correlation between SSTR and NMDAR is hence inferred in this review with the hope of finding a potential new therapeutic target for the treatment of SZ and related neurological conditions. © 2017 The Authors


Abu-Nada E.,Khalifa University | Chamkha A.J.,The Public Authority for Applied Education and Training
International Communications in Heat and Mass Transfer | Year: 2014

This work is focused on the numerical modeling of steady laminar mixed convection flow in a lid-driven cavity with a wavy wall filled with a water-CuO nanofluid. The left and right walls of the enclosure are kept insulated while the bottom and top walls are maintained at constant temperatures with the top surface being the heated lid wall and moving at a constant speed. The governing equations for this investigation are given in terms of the stream function-vorticity formulation and are non-dimensionalized and then solved numerically subject to appropriate boundary conditions by a second-order accurate finite-volume method. Various comparisons with previously published work are performed and the results are found to be in good agreement. A parametric study of the governing parameters such as the Richardson number, bottom wall geometry ratio (B/H) and the nanoparticles volume fraction is conducted and a representative set of graphical results is presented and discussed to illustrate the effects of these parameters on the flow and heat transfer characteristics. It is found that the presence of nanoparticles causes significant heat transfer augmentation for all values of Richardson numbers and bottom wall geometry ratios. © 2014 Elsevier Ltd.


Chamkha A.J.,The Public Authority for Applied Education and Training | Ahmed S.E.,South Valley University
Journal of Applied Fluid Mechanics | Year: 2011

The problem of unsteady mixed convection heat and mass transfer near the stagnation point of a three-dimensional porous body in the presence of magnetic field, chemical reaction and heat source or sink is analyzed. An efficient, iterative, tri-diagonal implicit finite difference method is used to solve the transformed similarity equations in the boundary layer. Three cases were considered, namely, accelerating flow, decelerating flow and the steady-state case. The obtained results are presented in graphical and tabulated forms to illustrate the influence of the different physical parameters such as the magnetic field parameter, transpiration parameter, unsteadiness parameter, ratio of velocity gradients at the edge of the boundary layer parameter, heat generation/absorption parameter and the chemical reaction parameter on the velocity components in the x-and y- directions, temperature and concentration distributions, as well as the skin-friction coefficients and Nusselt and Sherwood numbers.


Chamkha A.J.,The Public Authority for Applied Education and Training | Aly A.M.,South Valley University
Chemical Engineering Communications | Year: 2011

This work is focused on the numerical solution of steady natural convection boundary-layer flow of a nanofluid consisting of a pure fluid with nanoparticles along a permeable vertical plate in the presence of magnetic field, heat generation or absorption, and suction or injection effects. The model used for the nanofluid incorporates the effects of Brownian motion and thermophoresis. The governing boundary-layer equations of the problem are formulated and transformed into a non-similar form. The obtained equations are then solved numerically by an efficient, iterative, tri-diagonal, implicit finite-difference method. Comparisons with previously published work are performed and are found to be in excellent agreement. Representative results for the longitudinal velocity, temperature, and nanoparticle volume fraction profiles as well as the local heat transfer rates for various values of the physical parameters are displayed in both graphical and tabular forms. © Taylor & Francis Group, LLC.


Gorla R.S.R.,Cleveland State University | Chamkha A.J.,The Public Authority for Applied Education and Training | Rashad A.M.,Taibah University | Rashad A.M.,South Valley University
Nanoscale Research Letters | Year: 2011

A boundary layer analysis is presented for the mixed convection past a vertical wedge in a porous medium saturated with a nano fluid. The governing partial differential equations are transformed into a set of non-similar equations and solved numerically by an efficient, implicit, iterative, finite-difference method. A parametric study illustrating the influence of various physical parameters is performed. Numerical results for the velocity, temperature, and nanoparticles volume fraction profiles, as well as the friction factor, surface heat and mass transfer rates have been presented for parametric variations of the buoyancy ratio parameter Nr, Brownian motion parameter Nb, thermophoresis parameter Nt, and Lewis number Le. The dependency of the friction factor, surface heat transfer rate (Nusselt number), and mass transfer rate (Sherwood number) on these parameters has been discussed. © 2011 Gorla et al.


Chamkha A.J.,The Public Authority for Applied Education and Training | Aly A.M.,South Valley University
Chemical Engineering Communications | Year: 2011

This work is focused on the numerical solution of steady boundary-layer stagnation-point flow of a polar fluid towards a stretching surface embedded in porous media in the presence of the effects of Soret and Dufour numbers and first-order homogeneous chemical reaction. The governing boundary-layer equations of the problem are formulated and transformed into a self-similar form. The obtained equations are solved numerically by an efficient, iterative, tri-diagonal, implicit finite-difference method. Both assisting and opposing flow conditions are considered. Comparisons of the present numerical results with previously published work under limiting cases are performed and found to be in excellent agreement. Representative results for the fluid velocity, angular velocity, temperature, and solute concentration profiles as well as the local heat and mass transfer rates for various values of the physical parameters are displayed in both graphical and tabular forms. © Taylor & Francis Group, LLC.


Al-Maghrebi M.,Kuwait University | Renno W.M.,Kuwait University | Al-Ajmi N.,The Public Authority for Applied Education and Training
Biochemical and Biophysical Research Communications | Year: 2012

Testicular torsion (TT) is a urologic emergency that may result in future infertility problems. The pathologic process of TT is similar to an ischemia reperfusion injury (IRI). The purpose of this study was to evaluate the effect of epigallocatechin-3-gallate (EGCG) on reversing the damaging consequences of TT-induced IRI by examining its inhibitory effects on the expression of inflammatory and apoptosis mediators in a unilateral TT rat model. Eighteen male Sprague-Dawley rats were divided into 3 groups. Group 1 underwent a sham operation of the left testis under general anesthesia. Group 2 underwent ischemia for 1. h followed by 4. h reperfusion in the presence of saline. The third group was similar to group 2, however, EGCG (50. mg/kg) was injected i.p. 30. min after ischemia induction. The in vivo protective effect of EGCG was tested by measuring testicular levels of TNF-α, IL-6 and IL-1β by ELISA and mRNA expression of iNOS, MCP-1, p53, Bax, Bcl-2 and survivin by real-time PCR. Also, testicular morphological changes and damage to spermatogenesis were evaluated using H&E staining and Johnsen's scoring system, respectively. EGCG treatment improved testicular structures in the ipsilateral testis, markedly inhibited germ cell apoptosis (GCA) and significantly decreased testicular cytokine levels. In addition, EGCG was able to down regulate the mRNA expression of iNOS, MCP-1 and pro-apoptosis genes in favor of cell survival. For the first time we show that in vivo EGCG treatment rescued the torsed testes from IRI-induced inflammation, GCA and damage to spermatogenesis thus suggesting a new preventive approach to inhibiting the inflammatory and apoptotic consequences of TT-induced IRI. © 2012 Elsevier Inc.


Chamkha A.J.,The Public Authority for Applied Education and Training
WSEAS Transactions on Heat and Mass Transfer | Year: 2010

The problem of steady, laminar, coupled heat and mass transfer by mixed convective flow of a non-Newtonian power-law fluid over a permeable wedge embedded in a porous medium with variable surface temperature and concentration and heat generation or absorption and wall transpiration effects is considered. A mixed convection parameter for the entire range of free-forced-mixed convection is employed and a set of non-similar equations are obtained. These equations are solved numerically by an efficient implicit, iterative, finite-difference method. The obtained results are checked against previously published work for special cases of the problem and are found to be in good agreement. A parametric study illustrating the influence of the various physical parameters on temperature and concentration profiles as well as the local Nusselt and Sherwood numbers is conducted. The obtained results are illustrated graphically and the physical aspects of the problem are discussed.


Aloraier A.S.,The Public Authority for Applied Education and Training | Joshi S.,Concordia University at Montréal
Materials Science and Engineering A | Year: 2012

This paper reports the simulation results of 3D finite element analysis (FEA) of flux cored arc welding (FCAW) process in a single bead-on-plate weld and predicts the temperature distribution and residual stresses. The FCAW process was simulated using a nonlinear heat transfer analysis on the software Sysweld using the double ellipsoidal heat source model and a coupled transient thermo-mechanical analysis. Part of the experimental work was carried out before the FE modeling in order to obtain current, voltage, traverse speed and Gaussian parameters of the weld pool, which measure the bead geometry dimensions such as width, height, depth of penetration and size of the HAZ. The other part of the experimental work verified the results produced by the FEA in two steps - first, comparing the FEA thermal results with corresponding values measured using K-type thermocouples; and second, comparing the residual stresses in the FE model against those measured by the RS hole-drilling method. The FEA results showed good agreement with the experimental measurements and it is concluded that this model can be used as a future benchmark to calibrate larger scale weld repairs. © 2011 Elsevier B.V.


Alharbi A.,The Public Authority for Applied Education and Training
Library Hi Tech | Year: 2016

Purpose – The purpose of this paper is to describe the student perceptions of Information and Communication Technology (ICT) in the American University of Kuwait Library (AUK). Design/methodology/approach – The study uses a quantitative research method in order to investigate the perceptions of a wide range of students who use the academic library. The sample consists of 95 student volunteers, who provided data that were then analyzed and compared with literature from other authors in this subject field. Findings – The study found that the quality of the ICT equipment provided by the AUK library is very good, however training in how to use the library’s ICT is lacking. Practical implications – The findings suggest that the academic library looks into the possibility of changing the layout of the library to incorporate more computer terminals, as clearly many students feel there are currently not enough. The academic library must offer a greater amount of ICT training for students, preferably relating to the use of electronic resources and journals for new students. Originality/value – This study adds to the current literature on academic libraries in Kuwait, and is one of the first studies to look at students’ perceptions of ICT in a private university institution. © 2016, © Emerald Group Publishing Limited.

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