Auxiliary Winding Switching Circuit for Single-Phase Induction Motors

The most common practice for starting a single-phase induction motor is to connect a starting capacitor, in series, with the auxiliary winding. Here, the possibility of using an electronic switch in parallel with the starting capacitor, is discussed. This work relates particularly to a switching device for electrically connecting and removing the auxiliary winding and starting capacitor from the single-phase induction motor's circuitry. The starting capacitor with the auxiliary winding are disconnected by electronic means as the motor gains speed hence leaving only the main winding in the motor circuit for normal operation

Voltage Collapse and the Nigerian National Grid

A modern electric power system network (PSN) is typically a large and complex engineering system whose healthy existence is crucial to industrial and socio-economic development of Nations. Voltage instability and collapse contribute to large extent to system collapse or blackouts and it is one of the major concerns for today’s electric power system operations. The Nigerian National grid (NNG) experiences on an average of thirty-five (35) system collapse every year over the past ten (10) years. This paper presents an overview and classification of system collapse on the NNG. Keywords — Voltage collapse, Voltage instability, and Nigerian National Grid (NNG

Automatic Electrical Appliances Control Panel Based on Infrared and Wi-Fi: A Framework for Electrical Energy Conservation

-Today, proprietary home automation targets very specific applications which operate mostly on a cable based infrastructure. In contrast to that, our implementation builds on a wireless platform for the automatic control of house hold electrical appliances. The nodes gather sensor readings in a home and transmit them to a central automation server. There, the readings are matched against a list of script statements. When there is a match, a specific action is performed. An important property of the system is that the control of all home appliances is done by means of the ubiquitous Infrared and Wi-Fi wireless technologies. This way, the co-operation between manufacturers is not a necessity in order to connect devices to the home automation network

Compact QED3 with theta term and axionic confining strings

We discuss three dimensional compact QED with a theta term due to an axionic field. The variational gauge invariant functional is considered and it is shown that the ground state energy is independent of theta in a leading approximation. The mass gap of the axionic field is found to be dependent upon theta, the mass gap of the photon field and the scalar potential. The vacuum expectation of the Wilson loop is shown to be independent of theta in a leading approximation, to obey the area law and to lead to confinement. We also briefly discuss the properties of axionic confining strings.Comment: 35 pages, LaTex, typing error correcte

Nomadic Base Station (NBS): a Software Defined Radio (SDR) based Architecture for Capacity Enhancement in Mobile Communications Networks

In this research work, the problem of congestion that leads to dropped calls at GSM cell sites and drastic reduction in network capacity is addressed. We designed a novel GSM base station architecture named Nomadic Base Station (NBS) which is based on Software Defined Radio (SDR) architecture and simulated the LNA for its receiver front-end. The NBS receiver LNA selects and amplifies GSM signal bursts operating at 900MHz and 1800MHz Radio Frequency Band. The later stages translate the Radio Frequency (RF) signal to Intermediate Frequency (IF) signal. This implements the SDR technology by digitizing the IF signal into bit streams that can be processed on generic Central Processing Unit (CPU) using custom written signal processing software

Development of a Prototype Robot Manipulator for Industrial Pick-and-Place Operations

In the industry today, continuous attempts to realize optimal efficiency and increased productivity have spawned much progress in the use of intelligent automated devices and machines to perform various operations and tasks. The thrust of this work is to present the development of a three-degree-of-freedom revolute robot manipulator amenable to pick-and-place operations in the industry. Appropriate kinematic equations of the manipulator are obtained, and then used to develop algorithms for locating predetermined positions of a small object in a customized workspace. An Arduino-based controller circuit is built to implement the algorithms, and servomotors are used to carry out independent joint control of the manipulator. The positions of the object are identified with the aid of light-dependent resistors (LDR). Besides, in order to aid easy fabrication of links and overall system assembly, a 3D model of the manipulator is designed. The results of the work, showing effective and satisfactory operation of the manipulator, are presented

Shared values and organizational citizenship behavior of generational cohorts: A review and future directions

The literature implies that in the contemporary workforce, one of the interesting and challenging tasks of the management is to effectively handle different generations who possess various value systems. Hence, the foremost aspiration of the current study is to present the empirical evidence on the diverse characteristics and values of generational cohorts; the interests of HR specialists, managers and researchers in dealing with multigenerational workforce and their impact on work-related outcomes, the responsibility of management; the influence of values on behavior (especially, in-role and extra-role behaviours) and various positive outcomes to employees and organizations. This article also reviewed the previous studies related to shared values or P-O fit, OCB and highlighted that very little research was conducted in academic institutions. This study shows the generational categories from the Western context and the Indian context. It also intends to identify the gaps in the generational research and pave the way for further investigation. Finally, based on the research gaps identified, this article suggests and discusses the importance of generational difference on shared values and OCB in academic field in the Indian context as well as reframes the list of shared values from academic perspective for further investigation. Moreover, academic field is one of the predominant workplaces where intergenerational communication is at a high rate. Thus, the more attention needs to be given to the behaviours of generational cohorts in order to attain the goal of the institution

Shared values and organizational citizenship behavior of generational cohorts: A review and future directions

The literature implies that in the contemporary workforce, one of the interesting and challenging tasks of the management is to effectively handle different generations who possess various value systems. Hence, the foremost aspiration of the current study is to present the empirical evidence on the diverse characteristics and values of generational cohorts; the interests of HR specialists, managers and researchers in dealing with multigenerational workforce and their impact on work-related outcomes, the responsibility of management; the influence of values on behavior (especially, in-role and extra-role behaviours) and various positive outcomes to employees and organizations. This article also reviewed the previous studies related to shared values or P-O fit, OCB and highlighted that very little research was conducted in academic institutions. This study shows the generational categories from the Western context and the Indian context. It also intends to identify the gaps in the generational research and pave the way for further investigation. Finally, based on the research gaps identified, this article suggests and discusses the importance of generational difference on shared values and OCB in academic field in the Indian context as well as reframes the list of shared values from academic perspective for further investigation. Moreover, academic field is one of the predominant workplaces where intergenerational communication is at a high rate. Thus, the more attention needs to be given to the behaviours of generational cohorts in order to attain the goal of the institution

Fault Tree-Based Reliability Assessment of a 132-kV Transmission Line Protection Scheme

The reliability of a power system network depends greatly on the performance of the protection system. Improving the reliability of the protection scheme of the transmission lines will enhance the overall reliability of the power system network. The focus of this paper is the improvement of the reliability of a power system transmission line using fault tree analysis (FTA). The paper considers the development of fault tree diagrams for the protection scheme of the 150km-long 132-kV transmission line in Northern Nigeria. The existing protection scheme is analyzed and compared with a proposed scheme equipped with a redundancy arrangement. And the result shows that the new scheme offers significant improvement (about 51%) in the availability of the line