European Journal of Scientific Research

Volume 122 No 4
May, 2014

An Approach to Increase Capacity of CDMA Networks
360-368
M. Nasim Faruque and S. N. Ahmad
Abstract:
In this paper, we have analyzed the performance of Code Division Multiple Access system in wireless communication by using cell splitting technique. Here, we have considered a location area having a combination of larger cells which are further split into smaller cells to improve the capacity of the system. This is called cell splitting technique. In cell splitting, the highly congested larger cells known as macro cells are divided into smaller cells namely micro, pico and femto cells etc. each with their own base station and set of frequency channels. In cell splitting, a large number of low power transmitters take over an area previously served by a single, higher powered transmitter. Reduction of cell-radius makes the cell capable to handle extra traffic. When the traffic load on a particular site is generated, then more numbers of base stations are required to provide service to the customers. Each cell consists of one base station. The new cells have smaller radius than the larger cell and capacity increases as the number of channels per unit area increases. We have computed the processing gain, number of subscribers requesting for service within each type of cell, user-transmitted in-band signal power to achieve desired SNR, probability that a call attempt fails. Finally we have also compared the results by simulating their equations using MATLAB simulation software.
Keywords: CDMA, Processing Gain, Cell Splitting, Macro Cell, Micro Cell, Pico Cell, Femto Cell.

On a New Subclass of Meromorphic Univalent Functions with Negative Coefficients Defined by Liu-Srivastava Linear Operator
369-380
WaggasGalibAtshan, Ali Hussein Battor and Amal Mohammed Dereush
Abstract:
In The present paper, we introduce and discuss a new subclass of meromorphic univalent functions defined by Liu-Srivastava linear operator, we obtain various important properties, like, coefficient inequalities, extreme points, closure theorems,(n,δ) -neighhborhoods of a functions f ε Á and partial sums. We also consider integral transforms of functions in the class Á(g,γ,k,λ) and obtain some results.
Keywords: Meromorphic Univalent Functions, Liu-Srivastava Linear Operator, HadamardProduct, Extreme Points, Closure Theorems, Neighborhoods, Partial Sums, Integral Transform.
AMS subject classification: 30C45.

Microstructue and Mechanical Properties of Cast Mg-6Al-1Zn-XRE Alloy with Additions of Yttrium and Different Ageing Temperature
381-391
S. Manivannan, Sarathy Kannan G, Lakshmi Narayanan, S. P. Kumaresh Babu and Srinivasan Sundarrajan
Abstract:
Synthesis of cast Mg-6Al-1Zn-XRE alloy with various addition levels of RE element (Y = 0.0, 0.5, 1.0 and 1.5 wt. % of yttrium) were developed. The age hardening effect on the cast Mg-6Al-1Zn-xRE alloy (Y= 0, 0.5, 1.0 and 1.5) at different ageing temperatures of 160°C, 180°C, 200°C and 220°C for 24 hours has been investigated. An addition of 0.5 wt.% Y result shows higher grainrefinement and modification of ß- phase (Al12Mg17) compared with other weight percentage. High values of UTS, Yield Strength and Elongation are obtained in Mg-6Al-1Zn+ 0.5 wt. % Y at a 180°C ageing temperature due to the presence of fine precipitates of Al2Y along the magnesium matrix. Microstructural changes after the addition of yttrium and different aging temperature have been studied by using Optical and Scanning Electron Microscopy (SEM), intermetallic phases were confirmed by X-Ray Diffraction (XRD) and EDS.
Keywords: Corrosion, Magnesium alloy, Microhardness, Rare Earth and Yttrium.

Impact of Working Capital Management on Firms Performance: An Empirical Study Based on Pakistani Manufacturing Companies
392-413
Faisal Javaid and Muhammad Aslam
Abstract:
In business, cash is thought of as a king, if so then working capital is power behind the throne in any commercial enterprise. Working Capital Management has its effect on profitability as well as on liquidity of the manufacturing firms. More specifically this study investigates the impact of accounts payable days, accounts receivables days, inventories in days and cash conversion cycle on return of total assets in order to analyze the asset management and financing policy impacts on manufacturing firms’ performance. Moreover, we investigate relationship between liquidity and profitability, size of the firm and profitability, debt used by the firm and profitability. Finally we check efficiency of current assets in generation of revenue. For this research, we have selected a sample of 356 Pakistani manufacturing firms in thirteen major sectors listed on Karachi Stock Exchange for a period of 13 years spanning 1998 to 2011. Using panel data least squares method, we find that there is a significant negative association between profitability and working capital management, liquidity, and debt. While there is significant positive relationship between size of the firm and profitability.Moreover, working capital investment policy has a negative relationship with Return on Total Assets, whereas the relationship of Return on Total Assets with financing policy has been found to be positive.
Keywords: Working Capital Management, Cash conversion cycle, Investment and Financing policy, Manufacturing Firms.

Effect of High-Energy Electron Beam Irradiation on Corrosion Resistance of 413 Aluminum Alloy
414-423
M. Farnush and M. M. Esfandiari
Abstract:
The characteristics of corrosion improvement by high-energy electron beam (HEEB) have been investigated for 413 aluminum alloy. The corrosion resistance of 413 aluminum alloy under different bombardments was considerably improved due to the formation of a thin alumina layer (Al2O3). This process leads to the dissolution of second-phase particles and it would form thick homogeneous surface. The HEEB treatment includes heating and cooling at the top surface layer. It is possible that the localized corrosion occur along pores or cracks located mainly along grain boundaries and dislocations. The cracks propagate in parallel to the surface and some splats could fall out of the corroded surface, when using the HEEB and synchronous rapid cooling method, though the irregular-shaped particles remain unchanged inside the surface area. The overall results demonstrate the potential of the HEEB technique to improve the corrosion performance of the metallic materials.
Keywords: 413 aluminum alloy; High-energy electron beam; Corrosion resistance; Irradiation; HEEB.

Energy not Served Cost Studies in Gulf Cooperation Council (GCC) Countries: An Alternative of Additional Benefits from Battery Storage for Utilities Choices and Implementations
424-432
Jouda Bouattour, Lambert Pierrat and Abdelkader Mami
Abstract:
In today's aggressive business environment, every electric utility company including in Gulf Council Cooperation countries (GCC) need to know the value of service reliability to customers in order to validate investments in reliability enhancement projects. Distributed energy resources are being promoted to meet increasing demands; but, may distributed energy system improve the electric power supply reliability to customers? The developed hereafter is a tentative to overview the energy not served costs through different international references studies and analyses. Global method for the calculation of cost of energy not served in some GCC countries is accessible. More detailed is referring to United Arab Emirates cost study. Cost per sectors related are found and updated as per 2012 values. Some statistics failures in Abu Dhabi, were used to evaluate the distributed battery system used in substation, as a security system against the outage, and to calculate what avoided costs per year it can give.
Keywords: Energy not served cost, blackout, electrical power system reliability, battery storage, economical approach, Gulf Cooperation Council (GCC) Countries.

Electromagnetic Impedance and Phase Studies in Seismic Precambrian Area
433-445
Harlin L. Ekoro Nkoungou, Philippe Njandjock Nouck, Jacqueline Tchakounte, Dieudonné Bisso and Eliézer Manguelle Dicoum
Abstract:
Magneto telluric response with scalar data was developed by the combination of the Vozoff diagonal impedance tensor estimation and Schmucker phase to study the crust constraint, faulting network and deep anomalies. The results presented on this paper confirm that, this approach can be suitable to conduct structural study in unstable Precambrian zone.
Keywords: Magneto telluric response, Faulting network, Crust constraint, Critical fault, Resistivity.

Knowledge of Health Implications of Demineralised Water among Workers in Potable Drinking Water Producing Factories in Ilorin Metropolis
446-457
T. A. Adedeji, A. O. Awoyemi, N. O. Adedeji, O. A. Bolarinwa and R. S. Owolabi
Abstract:
Consumption of demineralized water can lead to serious health complications. We attempted determining the level of knowledge of health implications of demineralized water among workers in potable drinking water factories in Ilorin metropolis, Nigeria. Systematic random sampling method was used to select 43 factories. Interviewer- administered semi-structured questionnaire was employed as instrument. Only 34 (17.6%) of the respondents had professional qualifications related to water purification. Majority (66.8%) had attended at least one training on water purification. Only 26.4% had excellent in-depth knowledge of the different methods of water purification. Combination of sedimentation, filtration and ultraviolet radiation was the most used method. Most respondents 128 (66.3%) had excellent knowledge of the usefulness of water purification. About two-thirds of the respondents knew about minerals present in water. 38.3% knew the possibility and meaning of water demineralization. Mineral contents of the potable waters were less than minimum expected levels for magnesium and calcium. Only 70 (36.3%) of the respondents had good knowledge of health implications of demineralized water. Combination of sedimentation, filtration and disinfection would be the best to preserve health-maintaining minerals in drinking water. There is also a need for awareness campaign of health implications of demineralized water among the producers.
Keywords: Knowledge, Health, Demineralized water, Implications.

A Distributed Routing Protocol Based on Modular QOS in Wireless Sensor Networks
458-465
S. Anu and R. Umarani
Abstract:
Distributed Routing protocol based on modular quality of service (QoS) for wireless sensor networks (WSN) is proposed in this paper. The protocol functions based on the forwarding Node Capabilities and coverage range of WSN’s applications having different types of data traffic. Routing is performed based on differentiating QoS requirements according to the work load, which enables to provide several and customized QoS metrics for each traffic category in terms of data evolution and exploration. With each packet, the protocol attempts to fulfil the required data type and Forwarder type-related QoS metric(s) while considering network efficiency like Bandwidth, latency, Link weight etc. The System uses geographical information, which eliminates the need of propagating routing information. Multi Cluster and Minimum Node approach and Minimum Cluster and Multi Node approach is embedded into the system to increase reliability. For link quality estimation, the protocol employs distributed, resilient and computation efficient mechanisms. Experimental results proves that protocol is the first that makes use of the Distributed evolution handling in data traffic while considering latency, reliability, Bandwidth in sensor nodes. Extensive simulation analysis with multiple nodes shows the Distributed routing protocol outperforms all comparable state-of-the-art QoS and localized routing protocols.
Keywords: Wireless sensor networks, quality of service, geographical routing, distributed protocols, Energy Efficiency.

Essai De Modélisation Tridimensionnel D'un Gisement Cupronickélifère à Partir des Données Géophysique et Géologique Cas de Samapleu (Ouest de la Côte d'Ivoire)
466-482
Simon-Pierre Djroh, Loukou Nicolas Kouamé, Dja Denis Moïse Kouadio, Boko Célestin Sombo, Emile Gahé Agnaramon Koutoua and Jean-Raymond Akré Mobio
Abstract:
In Ivory Coast, the first occurrence of Copper-nickel was highlighted in 1976 to Samapleu in ground geochemical prospecting for research titanoferrite index. Several phases of study were performed on the index. First campaigns of geophysical and mechanical surveys, helped to highlight a significant polymetallic sulphide mineralization with the two dimensions (2D) model proposed by Camil J (1984). In order to develop the three-dimensional model of the deposit, we conducted this study to provide information needed to better characterize it. The modeling made from geophysical and logs surveys shows reduced mineralized horizons in lenticular form with a rock volume of about 16 million cubic meters of strike length.
Keywords: Copper nickel, polymetallic, modeling, geophysical.