Archives-August 2011

In this paper we present a relation for total stopping power of Carbon, Aluminium and Silicon for electrons and positrons in terms of total energy from 30 keV to 3000 keV and have been fitted by an exponential inverse power approximation with two parameters. These parameters depend upon the atomic weight (A) and atomic number (Z) of the absorber. It has been found that the exponential potential function gives better agreement with the available experimental data as compared to the inverse power form.

In this paper we present a relation for continuous slowing down approximation (CSDA) ranges for electrons of biomedical materials such as bones, muscles, fat, water and air in terms of energy from 20 keV to 50000 keV and have been fitted by least square approximation with two parameters. These parameters depend upon the total energy and atomic number of the absorber. It has been found that this method gives better agreement with the available experimental data.

In a previous related article the author described a trade union initiative to improve the health and safety performance of small enterprises in the agricultural sector through the introduction of a scheme for employee participation based on the appointment of a number of regional safety representatives (Walters, 1998). The article concluded that the scheme had achieved only limited success. The fundamental obstacles to its implementation were the aggressive attitudes of the employers’ organisation and the embedded insularity and anti-collectivist culture of farmers. . It suggested that many of its detailed findings in this respect, as well as those on the operation the scheme itself, would be relevant for the development of strategies on this form of representation for employees in small enterprises in other sectors of employment in the India. These points are taken up and further elaborated in the present article, which considers the possible role of schemes for regional representation in health and safety, as one means to improve health and safety management in small enterprises, and provides an analysis of the factors necessary to make them effective and support their development. The purpose of the present article is to explore their significance in the context of the development of forms of regional representation for employees in small enterprises. The article begins by reviewing the problem of health and safety in small enterprises, before considering the role of employee representation in improving health and safety organisation and the factors that make it effective. Its significance for small enterprises is explored with reference to the relevance of the existing legislative provisions and, more importantly, in the light of findings on the factors that promote or limit the effectiveness of the operation of employee representatives in small enterprises.

The Indian retail sector is going through a transformation and this emerging market is witnessing a significant change in its growth and investment pattern. Both existing and new players are experimenting with new retail formats. The growth and potential of the sector is being widely acknowledged both in the domestic as well as international forums. India topped AT Kearney’s Global Retail Development Index 2009 for the third consecutive year, retaining its position in the global market as the most preferred retail destination amongst emerging markets. Consumer dynamics in India is changing and the retailers need to take note of this and formulate their strategies and tactics to deliver value to the consumer. This paper investigates main advantages and disadvantages of modern retail developments and growth of modern formats in this country.

This paper is an account to politicization of bureaucracy and its impact on organization development and change in Tanzania. Through a historical approach, it examines the country’s political terrain and the way this has affected the ability of managers of public corporations to be the chief architects in managing changes in the organizations. The theoretical postulate of this paper is that the effectiveness and prosperity of public organizations largely depends on limited political influences and interferences in daily operations of these entities. The general observation that is noted, after a documentary analysis of the then public parastatals, privatized entities and other organizations that continue to be under the control of the government is that soon after independence to the era of the introduction of liberal policies in the country there was excessive politicization of bureaucracy which negatively deprived the managers of their presumed decision making autonomy thereby leading to poor performance of these organizations. It is however noted that since the adoption of liberalization policies positive developments that suggest relative managerial autonomy have taken place. It can however not be asserted that politicization tendencies are over as there are some organizations still suffering from this problem.

The aim of this paper is to present control of voltage magnitude and active power flow by means of a matrix converter. The matrix converter based compensator acts as the power electronic interface connected in series with a transmission line. Such a power system compensator consists of two power transformers and a three-phase to three-phase matrix converter. The compensator adjusts the active power flow on the transmission line and the voltage Magnitude at the bus of the power system. Pulsed Width Modulation (PWM) technique is employed as the switching strategy. Performance of the matrix converter based compensator is evaluated in the Simulink/MATLAB environment.

The optimal design of transmission system expansion planning is an important part of the overall planning task of electric power system. One of main keys of the successful grid expansion planning comes from optimal reliability level/criteria decision, which should be given for constraint in the optimal expansion problem. However, it’s very difficult to decide logically the optimal reliability criteria of a transmission system as well as generation system expansion planning in a society. The technique proposed in this paper is a “novel but classic” technique. We classify the transmission planning into three dimensions including Line Loading Index (LI), Voltage Profile Index (PI), and Expected Energy Not Supplied (EENS) Index with detailed definitions. Transmission Expansion Index (TEI) is the main focus of this paper and can be used as an important criterion for decision making and transmission planning in the planning horizon. The 6 bus system case study results demonstrate that the proposed method is practical for solving the power system expansion planning problem.

This paper presents optimal cross section selection of MV feeders in radial power distribution system planning to reduce power loss and improve voltage profile using genetic algorithm. To analysis the steady state of network in each step of optimization, a direct approach load flow which is both robust and efficient and has high convergence speed is used. In this paper, feeder cross section selection will be performed considering the economic, power loss, and energy loss factors so that, constraints like maximum current capacity of feeders and allowed voltage drop of nodes are satisfied. The obtained result of feeder cross section selection problem will be close to absolute optimum point because of using genetic algorithm as an optimization tool. The proposed method is implemented on MATLAB software environment and through numerical example the validity of proposed method is verified.

In this paper, an attempt has been made to develop a new algorithm for distribution system planning. The proposed algorithm does not require prior knowledge of candidate substation location and can obtain the “number, location and service area” of HV/MV substations, the optimal feeder configuration and the optimal sizes of branch conductors while satisfying constraints such as current capacity, voltage drop and heuristic rules. Several algorithms are proposed for distribution systems planning. A comprehensive algorithm is developed for obtaining the optimal “number, location and service area” of substation using GA and a generalized algorithm is modified to optimal feeder path on minimum loss criterion. Direct approach load flow is used for solving radial distribution networks and branch conductor optimization algorithm. The load flow algorithm and branch conductor optimization techniques are used as subroutine in the generalized distribution systems planning algorithm. Through numerical example the validity of proposed method is verified.

The Indian retail sector is going through a transformation and this emerging market is witnessing a significant change in its growth and investment pattern. Both existing and new players are experimenting with new retail formats. The growth and potential of the sector is being widely acknowledged both in the domestic as well as international forums. India topped AT Kearney’s Global Retail Development Index 2009 for the third consecutive year, retaining its position in the global market as the most preferred retail destination amongst emerging markets. Consumer dynamics in India is changing and the retailers need to take note of this and formulate their strategies and tactics to deliver value to the consumer. This paper investigates modern retail developments and growth of modern formats in this country. We also discuss the challenges and opportunities available to the retailers to succeed in this country.