Effects of geometry and PVP addition on mechanical behavior of PEI membranes for use in wastewater treatment

This study focuses on the mechanical behavior and design of membrane filters that are used in water and wastewater treatment. The aim of this study is, after characterizing the mechanical behavior of the membrane materials, to find a better shape in terms of mechanical parameters. As the first step, uniaxial tensile testing is applied to the produced polymeric membranes with certain contents of poly(ether imide), poly(vinylpyrrolidone), and N-methyl-2-pyrrolidone to get an understanding of the mechanical behavior of the membrane materials. The material data obtained from this experimental process are used as input to software where a finite element model of the membrane is built. Each geometry has the same boundary conditions and the same area, and the same pressure is applied to each geometry. Using these numerical models, the selected geometries are analyzed in terms of displacement, equivalent stress, and equivalent strain. The results are discussed based on these parameters. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47073.     

Radar cross section (RCS) modeling and simulation, part 1: a tutorial review of definitions, strategies, and canonical examples

Modeling and simulation strategies for radar cross section (RCS) prediction are reviewed, and a novel FDTD-based virtual RCS prediction tool is introduced in this two-part paper. Part 1 is reserved for a tutorial review. Concepts and definitions related to RCS modeling are outlined. Analytical approaches, i.e., high-frequency asymptotics (HFA), as well as powerful time- and frequency-domain numerical methods, are given. Canonical examples using the finite-difference time-domain (FDTD) Method, the method of moments (MoM), and physical optics (PO) are presented.     

A MATLAB-based visualization package for planar arrays of isotropic radiators

This article introduces a simple MATLAB antenna package (ANTEN/spl I.bar/GUI) for the visualization of the radiation patterns, beamforming, and beam-steering capabilities of user-designed planar arrays of isotropic radiators. The package can be used as an educational aid, especially in antennas and propagation lectures.     

An intelligent balance

This paper discusses the intelligent balance, which has been established between real and virtual experiments and it also gives skills that have not covered in conventional electronics and communication engineering. Engineering is the art of applying scientific and mathematical principles, experience, judgment and common sense to make things that benefit people. The explosive growth of computer capabilities and easy access to nanominiature devices has revolutionized communication and the analysis of complex systems. The EC engineer either individually or as a member of a team, can play an important role in this technical diverse mosaic and this community prepares to adapt frequency shifts in technical priorities. EC engineers should be given computers hand-on-practice and training and also should understand the physics of the problem and fundamental theorem.     

Determining Attribute Weights in a CBR Model for Early Cost Prediction of Structural Systems

This paper compares the performance of three optimization techniques, namely feature counting, gradient descent, and genetic algorithms (GA) in generating attribute weights that were used in a spreadsheet-based case based reasoning (CBR) prediction model. The generation of the attribute weights by using the three optimization techniques and the development of the procedure used in the CBR model are described in this paper in detail. The model was tested by using data pertaining to the early design parameters and unit cost of the structural system of 29 residential building projects. The results indicated that GA-augmented CBR performed better than CBR used in association with the other two optimization techniques. The study is of benefit primarily to researchers as it compares the impact attribute weights generated by three different optimization techniques on the performance of a CBR prediction tool.     

Sustained-Release Dosage Form of Nicardipine Hydrochloride: Application of Factorial Design and Effect of Surfactant on Release Kinetics

Microcapsules of nicardipine hydrochloride with core:wall ratios of 1:1, 2:1, and 1:2 were prepared by the coacervation-phase separation method, using ethyl-cellulose as the coating material. Two batches of nicardipine hydrochloride microscapsules were divided into size fraction by using standard sieves ranging from 840 μm to 476 pn. Dissolution rate studies from microcapsules were performed using the USP XXII basket method. The kinetic model according to the Rosin-Rammler-Sperling-Bennet-Weibull (RRSBW) distribution was applied for the parametric representation of the dissolution curves. Preparation and dissolution rate studies on the nicardipine hydrochloride microcapsules were pellformed and the influence of particle size, core:wall ratio, and the amount of nicardipine hydrochloride on the release rate was examined by 2³ factorial design. The sign@cance of the observed effects was tested with the F test. A surface active substance was added in the dissolution medium to understand how this substance effects the release of drug from ideal microcapsule form which is found by the findings of the 2³ factorial design. Dissolution studies were repeated with this ideal formulation using different ratio of Tween 20.

The results of this study suggested that the solubility and bioavailability of the sustained-release dosage forms of nicardipine hydrochloride using sullface active substances could be increased.     

Psychosocial aspects of genital herpes virus infection.

Reviews studies of psychosocial aspects of genital herpes virus infection. The fact that no cure is yet available has contributed to the heightened emotions caused by this sexually transmitted disease. Significant moral overtones exist for many people, and powerful social stigma are associated for many. Depression, anger, hostility, and reduced self-esteem have been reported among herpes sufferers. Alterations in sexual activity are common. The relationship between stress and recurrence has been examined. Results, although not fully conclusive, support the role of stress and emotional factors in the disease process. In terms of areas of future research, the interactive role of behavioral, emotional, and social variables and the immune system must be examined. (PsycINFO Database Record (c) 2010 APA, all rights reserved)