Archives-December 2011

Voltage instability problems have become important issues in unbalanced distribution networks. In this paper, a new bus positive sequence voltage index of Vcollapse/Vbase-load is introduced to identify the weakest three-phase buses in unbalanced three-phase distribution networks. First, the proposed ranking index is validated based on grid losses and PV curves without and with compensation devices. Then, the index is utilized to place three-phase DG without and with SVC devices at the three-phase weakest buses of the modified IEEE unbalanced 13 node test feeder using the DIgSILENT Power Factory software. Finally, simulation results are presented to show the application of the proposed approach in improving voltage stability and increasing the maximum loading factor under unbalanced loading and/or network conditions.

The levels of organochlorine pesticides and polychlorinated biphenyls were analyzed in four different fish species sampled from the Volta lake in Ghana. Fish muscles were subjected to soxhlet extraction for 16 h and further analysed by Gas Chromatography. The mean concentration of the HCHs, Drins, DDTs CHLs and HCB ranged from 4.03 to 13.04 ng/g; 3.46 to 12.29 ng/g; 7.96 to 38.05 ng/g; 4.55 to 39.62 ng/g and 0.34 to 1.21 ng/g respectively. Chrysichthys nigrodigitatus, Clarias gariepinus, Oreochromis niloticus and Tilapia zilli were the increasing order of magnitude of organochlorine pesticides detected among the species of fish. PCB concentration in the fishes ranged from a minimum of 0.90 ng/g to a maximum of 7.76 ng/g. The potential effect of contamination was assessed through the calculation of acceptable daily intake of organochlorines in the different fish species prescribed for human consumption. It was observed that the exposure of Ghanaian population through the consumption of fish from the Volta lake is relatively low and does not presently pose significant health risk.

In the present investigation, a linear model has been proposed which has been found very useful in growth studies wherever phenomenon exhibit asymptotic behavior. It possesses the identical properties those of Stevens’s asymptotic regression growth model i.e. it belongs to the family of convex-concave curves and has neither maxima nor minima nor a point of inflexion. Its appropriateness and utility has also been examined with the help of data sets obtained from different areas of growth studies showing asymptotic nature. It has also been compared with Stevens’s asymptotic regression model. An improvement has been shown over Stevens’s asymptotic regression model.

This paper aims to integrate Satellite Remote Sensing (SRS), Geographic Information System (GIS) and Digital Image Processing (DIP) techniques for the identification of flood affected areas and flood damage assessment along the Indus River as a result of flood in the year 2005 due to abrupt snow melt in the northern areas of Pakistan. Snow melt in northern areas of Pakistan was the main cause of flooding in the year 2005, using ER Mapper Image Processing software, study of temporal changes of snow cover has also been carried out by calculating the snow cover area in the month of February for different years i.e. 2004, 2005 and 2006 using Moderate Resolution Imaging Spectro-radiometer (MODIS) onboard Aqua and TERRA satellites data. This showed that snow covered areas for the mentioned years were 56203, 67853 and 58642 sq km respectively. Calculations also reveal that the snowfall was maximum in the year 2005. Using satellite images of MODIS for May and July 2005 covering the area along the Indus from Chashma to Sukkur Barrage showed that this flood had caused huge damage in many cities of Punjab and Sindh provinces. Using images pertaining to pre and post-flooding periods, the evaluated flooded area between Chashma Barrage and Sukkur Barrage comes out to be approximately 6428 sq km (excluding the normal flow area which is 1359 sq km).

There are many ways to minimize the failure of the structures made up of reinforced concrete. The custom approach is to adhesively bond fiber polymer Composite on to the structure. This also helps to increase the toughness and tensile strength & to improve the cracking & deformation characteristic of the resultant composite. But this method adds another layer, which is prone to degradation, when exposed to marine environment due to surface blistering. As a result adhesive bond strength is reduced, which results in the de-lamination of composite. So, the approach is to use fibers in concrete known as FRC. This method of reinforcing the concrete substantially alters the properties of non-reinforced cement based matrix which is brittle in nature, possesses little tensile strength compared to the inherent. Compressive strength.

Tensile stresses on concrete leading to the formation of cracks which further leads to the spalling of concrete. To overcome this shortcoming, due to its high tensile strength, ductility, ability to arrest propagation of cracks, improved bond strength, etc. This paper investigates the different strengths of Steel Fiber Reinforced Concrete (SFRC) using Fly ash as cement replacement. Silica fume and fly ash are the by-products and so has the uncontrolled engineering properties which sometimes don’t give the required results. The objective of this paper is to study the behavior of fly ash concrete with steel fibers under shear and torsion.

Students’ satisfaction has become an essence of success in today’s highly competitive world. In service industry specifically the education industry, communication is vital to determine students’ satisfaction. Past researches indicated that, most meaning of conversational messages comes from non-verbal communication. Evaluation on students’ perception on lecturers’ kinesics that would lead to their satisfaction to the services provided was examined. The results of the study illustrate that kinesics that is also known as body movements was shown to have the most impact on students’ satisfaction. Therefore, from this study, it can be inferred that students’ in Malaysian universities are mostly observant on the body movements used, facial expression and postures and gestures of the body of their lecturers when lectures are delivered to them. The present study caters for a wide spectrum of students and development professionals, especially those who are interested in non-verbal communication specifically kinesics-related issues. It is highly hoped that the information gleaned from the present study may assist all service employees specifically in understanding better, the importance of kinesics and its effects on students’ satisfaction.

The organizational commitment helps business executives effectively implements ethical leadership in organizations. To improve organizational commitment, business executives depend greatly on perceived of leader integrity (PLI). PLI is particularly relevant in architect the ethical leadership structure of organizations in order to ensure employees are modelled with ethical decisions that are critical to the organizations’ sustainability. At the same time, an ethical climate concept proposes a system that guides the ethical comprehension for better commitment towards the organizations. While perceived organizational support (POS) is a support system within the organization that compensate employees in lieu to commitment demonstrated. This study makes a significant contribution by developing a proposed model as a methodological example which can be useful for tracking the degree of PLI, ethical climate and POS on organizational commitment in profit oriented organizations and the non profit oriented organizations.

Leaders are backbone in an organization. They are the one that determine the direction of an organization whether to be further victorious or not. Leaders have an undeviating and massive impact on the followers as well. Past research indicated that when followers are selecting their leaders it is based on many indistinct characteristics. Thus this study is to identify the characteristics that develop into the factors to select a good leader among students. Findings from this present study indicated that from the five dimension of independent variables (responsibility, education, personality, skill and gender), three (education, personality and skill) were directly associated with selecting a good leader among the students. Among the three, education had the biggest impact on selection of a good leader among students. Education being the most imperative factor because a leader with first-class education will gain reverence without much difficulty, be trusted and their words are considered to be more significant and grant greater impact on the followers. It is highly hoped that information gleaned from this present study will shape and produce leaders with first-class qualities for the world of tomorrow.

This paper reports the effects of sintering schedule to the mechanical properties and microstructure of warm formed powder compacts. Iron powder ASC 100.29 was used as main powder constituent whereas zinc stearate was used as lubricant. The premixed powder mass was compacted at 180ºC by applying 130 kN axial loading and sintered in an inert gas fired sintering furnace at different sintering schedule. The sintered samples were characterized to evaluate their mechanical properties and microstructures. The effect of sintering schedule was studied in terms of mechanical properties, focusing in particular on the relative density, flexural strength and hardness. The microstructure analysis was performed to determine the pore shape, size and distribution. The results revealed that the mechanical properties and microstructures of sintered products were affected by the sintering temperature, holding time as well as the heating/cooling rate.