Consider uniform flow past an oscillating body. Assume that the resulting far-field flow consists of both steady and time periodic components. The time periodic components can be decomposed into a Fourier expansion series of time harmonic components. The form of the steady component in terms of the steady oseenlet is well-known. However, the time-harmonic components in terms of the oscillatory oseenlet do not yet appear to be in the literature.

In the AC/DC transfer mode the converter works as a rectifier with near sinusoidal input currents (RNSIC), while in the DC/AC transfer mode it works as a square-wave pulse switching inverter. Some suggestions for the converter design are given and a comparison with two–quadrant PWM converter is made.

This paper deals with the problem of delay-dependent stability criterion of discrete-time recurrent neural networks with time-varying delays. Based on quadratic Lyapunov functional approach and free-weighting matrix approach, some linear matrix inequality criteria are found to guarantee delay-dependent asymptotical stability of these systems. And one example illustrates the exactness of the proposed criteria.

Electrical discharge machining (EDM) is widely used process in the production of mould / dies, aerospace, automobile and electronics industries where intricate complex shapes need to be machined in very hard materials. The selection of the AISI 64430 was made taking into account its wide range of applications in the industrial field: defense, pharmaceutical, aerospace, shipbuilding industries etc. In this paper an attempt has been made to develop the mathematical model for predicting die-sinking electrical discharge machining of AISI 64430 (HE 30) aluminum alloy characteristics such as the metal removal rate (MRR), the tool wear rate (TWR), the surface roughness (Ra value) and the hardness(HRB) using fuzzy mathematical method. The process parameters taken in to consideration were the current (I), the open-circuit voltage (V), the servo (Sv) and the duty cycle (η). A fuzzy rule base characterizing the relationship between input and output parameters was built through experiments. The design of experiments technique has been used to conduct the experiments, which in turn reduced the number of experiments. The prediction of metal removal rate, the tool wear rate, the surface roughness and the hardness was achieved under the condition of given input parameters by rule-based fuzzy reasoning. The predicted results were analyzed through experimental verification. The model predicted values and measured values were fairly close to each other. To have more precise investigation into the model, a regression analysis of experimental and predicted outputs was performed. It was found that the R² (R: coefficient of determination) values are 0.9015, 0.9702, 0.9932 and 0.844 for the metal removal rate, the tool wear rate, the surface roughness and the hardness, respectively.

One of the primary needs for socio-economic development in any nation in the world is the provision of reliable electricity supply systems. This work is a development of an indigenous technology hybrid Solar -Wind Power system that harnesses the renewable energies in Sun and Wind to generate electricity. Here, electric DC energies produced from photovoltaic and   wind turbine systems are transported to a DC disconnect energy Mix controller. The controller is   bidirectional connected to a DC-AC float charging-inverter system that provides charging current to a heavy duty storage bank of Battery and at the same time produces inverted AC power to AC loads. The 2002-2009, 8years wind velocity data for Abeokuta and its environs were collected. The two parameters Wielbull distribution was used to simulate power in W/m² densities for the 8-years period. The step by step design of 1000W solar power supply system’s was done as a sample case. Load estimates of a typical rural community and for rural ICT infrastructures were estimated. Simulation of wind power capacity in W/m²   in Abeokuta, Ogun State Nigerian   was done based on the obtained wind data. The results showed that the average exploitable wind power density between 4W/m² and 14.97W/m² is realizable and that development of hybrid wind-solar system for off- grid communities will go a long way to improve socio-economy lives of people.

European directive (particularly the directive 97/43/EURATOM) and the various publications of Commission of European Communities (CEC) may be considered as landmarks of the new approach to the problems of dose reduction and quality in diagnostic radiology. The CEC publication includes examples of good radiographic technique for a number of common X-ray examinations, which if these guidelines are followed, compliance with dose and image quality criteria as specified in the document should be demonstrated. Studies in some countries have shown that a number of X-ray departments are not using optimum techniques. This study aimed at examining level of adherence of some selected hospitals in Nigeria to the CEC guidelines. Four hospitals were considered in the study, three of which are University Teaching Hospitals and Public Hospital. The following details on techniques and equipment were recorded for chest, abdomen, pelvis, skull and lumber spine examinations of standard sized patients: tube potential (kVp), focus-to-film distance (FFD), automatic exposure control (AEC), film-screen combination. From the study, varying level of adherence to guidelines were evident, with no hospitals demonstrating 100% compliance.

The proximate composition, ascorbic acid content and anti-nutrient composition of Chrysophyllum africanum fruits was investigated. The proximate composition analysis showed the results to be, moisture 66.67%, Carbohydrate 78.34%, protein 5.66%, fibre 4.50%, fat 9.83%, ash 2.12% and total energy value 420.42 kcal The ascorbic acid content was 19.68%.The anti-nutrients composition was observed to be oxalate 4.95mg, saponins 3.66 %, Cyanogenic glycoside 0.17%, phylate 0.02% and tannins 0.03 %.The study showed that Chrysophyllum africanum fruit contain high carbohydrate and this makes it a good source of energy for human nutrition while the high moisture content gives it a very short shelf life.

The study aims to demonstrate the role of internal audit as a pillar of support for management. The paper will present how the internal audit helps the organization to achieve its objectives by evaluating, through a systematic and methodical approach, its risk management processes, control and governance by formulating proposals for enhancing its effectiveness. In the present study are made on the conceptual concepts of internal control and internal audit highlighting the significance and role of internal audit in providing advice, counseling feedback strands within an organization. It is discussed in this paper and delineation of objectives and scope of activity of internal audit and internal public audit. During much attention is paid to the work of internal audit planning as it appears from research and case studies that incorrect or incomplete planning leads to a loss of risk-bearing activities. The practice requires careful selection of activities in high risk areas audited, based on the risks associated with these activities. It follows from the analysis of economic and financial and administrative practices of firms, the performing case studies, the effectiveness of internal audits is expected if we apply a risk management policy. Therefore in the paper, which thus completed the theoretical component applied this policy are outlined objectives, criteria for risk assessment, a model of analysis and evaluation of risk (resulting from the analysis of international good practice) guidelines for establishing criteria for prioritization risk identification procedure and risk analysis, risk assessment methodology for the preparation of internal audit plan.

The quality of leadership is one of the most important factors in determining the success and survival of groups and organizations. The purpose of this paper is to examine the leadership needs of the project leader in the Libyan construction companies. The objective was identified the most important and crucial personal and professional needs of the project manager. This study attempted to identify the needs of the project leaders in the construction industry in Libya. As results, this paper was found that the factor “concise and rational” ranked as the first personnel needs factors. Meanwhile, “versatile” was considered the first professional needs that the project leaders should possess.