Archives-July 2013

This paper presents a new topology for a seven-level cascaded H-bridge multilevel inverter. The proposed topology uses reduced number of switches and requires only one DC source. The new topology results in reduced cost and can be implemented for any number of levels. The proposed seven level inverter is simulated in MATLAB-Simulink. The switching angles are generated using a new technique of selective harmonic elimination technique. The simulated waveforms of output voltage have reduced total harmonic distortion.

Mobile Ad hoc Networks is a collection of wireless mobile nodes, which form temporary networks without relying on any existing infrastructure or centralized administration or standard support services regularly available in wide area networks to which the host may normally be connected. In this paper we proposed new distance vector routing algorithm (DVRA) for detecting and correcting the black hole and grey hole attack made by intruding nodes.

Suspension Polymerization was used for the synthesizing of cross-linked polystyrene-divinylbenzene (PS-DVB) containing 16% DVB. For application of these resins as columns’ filler in ion-exchange chromatography; the sulfonation reactions were done by acetyl sulfate and in the presence of methylene chloride as solvent at 60°C. The exchange capacities of cation exchange resins X-16 (CE=225 meq/100g) was determined by titration procedure. The structure of PS-DVB resin was investigated by scanning electron microscope (SEM) technique. The SEM images showed that the porous structure of PS-DVB resin was approximately maintained intact after sulfonation reaction. TGA and FTIR techniques were used to investigate the thermo gravimetric analysis and structures of obtained resins, respectively.

Styrene-divinylbenzene copolymer is a special macroporous strong base anion resin crosslinked with divinylbenzene that is specially selective for hydrophobic anions. It shows good mechanical strength and an excellent resistance to osmotic and thermal shock. The amination reactions were done by chloro dimethyl ether solvent at 45°C. TGA and FTIR techniques were used to investigate the thermo gravimetric analysis and structures of obtained resins, respectively. The exchange capacities of anion exchange resins (X-16) are 312 meq/100g as determined by titration method. Then the structure of PS-DVB resin was investigated by scanning electron microscope (SEM) technique. The SEM images showed that the porous structure of PS-DVB resin was approximately intact after amination reaction.

Although the magnetic field is an indispensible environmental factor for plants in soil, there is dearth of research regarding its effect on plant growth. In order to evaluate the effect of magnetic water on concentration of micronutrient elements in basil leaves, the present experiment was conducted under completely randomized factorial design with two treatments and three replications in greenhouse. The treatments consisted of the kind of water (magnetic and nonmagnetic water) and salinity treatment in three levels (distilled water, 30 mM and 50 mM salinity). The results indicated that the maximum effects on Mn, Zn and Cu concentration in basil leaves were produced by magnetic water. Concerning salinity treatments, the maximum effects on Mn, Zn, Cu and Total Fe in basil leaves were for water with 30 mM salinity. The interaction effects between the kind of water and salinity levels showed that maximum effects on these elements were related to magnetic distilled water.

Determination of optimum turning parameters in turning operations is one of the important tasks of process planners. The importance of this task is due to the fact that the values of turning parameters affect such objectives as turning time, turning cost and surface roughness. Thus, this problem is a multi-objective decision-making issue meaning that a parameter setting which satisfactorily achieves one of these objectives, it may not be good with respect to other objectives. Therefore, a rational compromise is to be made among these objectives. This paper determines the best cutting parameters considering relevant constraints in turning operations using a genetic algorithm coupled with an Analytic Hierarchy Process approach. The main stages of the proposed approach are two folds: (a) the non-dominated turning parameters being in the Pareto frontier are identified through a genetic algorithm, and (b) the AHP method is used to select the most suitable values for turning parameters from amongst the non-dominated solutions obtained in the first stage. Application of the proposed approach is demonstrated though an illustrative numerical example.

Wavelet transforms enable us to represent signals with a high degree of scarcity. Wavelet thresholding is a signal estimation technique that exploits the capabilities of wavelet transform for signal denoising. The aim of this paper is to study various thresholding techniques such as Sure Shrink, Visu-Shrink and Bayes Shrink and determine the best one for image denoising. This paper presents an overview of various threshold methods for image denoising. Wavelet transform based denoising techniques are of greater interest because of their performance over Fourier and other spatial domain techniques. Selection of optimal threshold is crucial since threshold value governs the performance of denoising algorithms. Hence it is required to tune the threshold parameter for better PSNR values. In this paper, we present various wavelet based shrinkage methods for optimal threshold selection for noise removal.

Enterprise informatization is a procedure in which IT is applied into the field of enterprise production, technology, and management, to improve the cost-effectiveness of exploration of informational resources and obtain financial profits. Enterprise informatization consists of three main aspects, the automation and flexibility of production, the integrative management and the systemic organization. The capacity of enterprise informatization is a resources-based capability, which has technical, manageable and organizational properties; it is divided into the three categories, which include information technology capability, information organizing capability and information innovation capability. Enterprise informatization capability can improve business performances, in this study we do the research on informatization capability how to increase enterprise’s competitive advantages in synergy, integration of customer relationship management, e-supply chain management, as well as global opportunities.

In this communications, the concept of Pathos Adjacency Line graph PAL(T) of a binary tree T is introduced. We decompose PAL(T) of T in to an edge disjoint complete bipartite subgraphs and then give the reconstruction of T. We also present a characterization of those graphs whose pathos adjacency line graphs are planar, outerplanar, maximal outerplanar, minimally non-outerplanar and non-Eulerian.

The production of full fat yoghurt from full cream milk enhanced with ginger extract and sodium benzoate with a view to improve its nutritional quality and shelf life was carried out. The pH of the yoghurt samples were determined, as incubation time increased the pH of the samples reduced. The yoghurt with 5000mg/L of sodium benzoate had the lowest pH of 4.2, while yoghurt with ginger extract had the highest pH of 4.8. The organoleptic evaluation was conducted by ten panel members to assess: appearance, sourness, consistency, aroma, taste and general acceptance; yoghurt with ginger was rated the best and the most acceptable. Proximate analysis was carried out to evaluate nutritional composition such as: crude protein, fiber, fat, moisture and ash contents; yoghurt with ginger extract had the highest protein content of 10.44% while the control sample had the lowest (3.59%). Also, the control sample had the highest fat content of 3.71% while yoghurt with ginger extract had the lowest (1.58%). The shelf life of the four yoghurt samples were monitored and the control had the lowest shelf life of three weeks, followed by yoghurt with 2500mg/L of sodium benzoate had shelf life of eight weeks, while the yoghurt with ginger extract and yoghurt with 5000mg/L of sodium benzoate had the highest shelf life of three months. Lactic acid bacteria and non-lactics isolates were isolated from the yoghurt. The isolates were characterized and identified as Lactobacillus brevis, Lactobacillus casei, Lactobacillus plantarum, Lactobacillus lactis, Lactobacillus bulgaricus, Bacillus cereus, Pseudomonas fluorescens, Proteus mirabilis, Pseudomonas chlororaphis, Bacillus subtilis. The total bacteria colony count of each of the samples was monitored for four weeks and the control sample had the microbial load of 2.0 x 104 in the first week after production and increased to >6.0 x 107 in the fourth week. The ginger preserved cheese had the lowest microbial load of 2.0 x 102 in the first week and increased to 5.0 x105 in the fourth week. Therefore, the high cost and side effect of chemical preservatives could be overcome by the application of biological preservatives particularly ginger extract which added to the nutritional value of the yoghurt, it also demonstrated a good preservative property.