Assessment of Pre-Stressed Concrete Electric Poles for Rural Electrification Projects

Rural electrification is the process of bringing electrical power to rural and remote areas in a country in order to improve the living conditions of the people. In accordance with the extant electricity regulation act chapter 106 Laws of the Federal Republic of Nigeria (1990) Part VI No 47 (i), every support carrying electric lines shall be made of treated wood, steel or reinforced concrete or any combination of such materials or other approved materials. Regulation No 47, (2)(1990), further stipulates that every support shall be so constructed to withstand the transverse, horizontal and vertical loads. Hence, in order to confirm that any pre-stressed concrete electric pole is acceptable and fit with adequate strength for rural electrification projects, a test or assessment was carried out. After the test, a safety factor of above 2.0 units was obtained and the cube test result satisfied the minimum strength of 40N/mm2 for the pre-stressed concrete pole

Food Expenditure Patterns Among Urban Households In Ibadan Southwest Local Government Area, Oyo State

This study examines food expenditure patterns among urban households in Ibadan South West Local Government Area of Oyo State. The primary data used for the study were obtained through structured questionnaire using random sampling technique. Descriptive statistics and least square regression model were used to analyse the data collected from respondents. Descriptive analysis showed that 82.5% of the household heads were males, 65% of them were married, and 55% fell within the age bracket of 30 and 39 years, while 65% were salary-earners. Most of the respondents (79.2%) had tertiary education and the average household size was found to be 5. Furthermore, 49.2% bought foodstuffs from the market for home consumption on a monthly basis and 52.5% spent less than N10, 000 monthly on food.  The result of the least square regression model showed that the age of respondents, level of education and occupation (salary-earner or self-employed) of the household head, as well as the household income were significantly influenced by household’s monthly food expenditure in the study area. The study recommends among other things enlightenment programmes that will    educate the urban dwellers on the  need to eat good quality and hygienic food.   &nbsp

Numerical and experimental assessment of the modal curvature method for damage detection in plate structures

This paper is concerned with the use of numerically obtained modal curvatures for damage detection in both isotropic and composite laminated plates. Numerical simulations are carried out by using COMSOL Multiphysics as FEM solver of the governing equations, in which a Mindlin-Reissner plate model is assumed and defects are introduced as localized smoothed variations of the baseline (healthy) configuration. Experiments are also performed on steel and aluminum plates using scanning laser vibrometry. This study confirms that the central difference method greatly amplifies the measurement errors and its application leads to ineffective predictions for damage detection, even after denoising. As a consequence, different numerical techniques should be explored to allow the use of numerically obtained modal curvatures for structural health monitoring. Herein, the Savitzky-Golay filter (or least-square smoothing filter) is considered for the numerical differentiation of noisy data

Numerical and experimental assessment of the modal curvature method for damage detection in plate structures

Use of modal curvatures obtained from modal displacement data for damage detection in isotropic and composite laminated plates is addressed through numerical examples and experimental tests. Numerical simulations are carried out employing COMSOL Multiphysics as finite element solver of the equations governing the Mindlin-Reissner plate model. Damages are introduced as localized non-smooth variations of the bending stiffness of the baseline (healthy) configuration. Experiments are also performed on steel and aluminum plates using scanning laser vibrometry. The obtained results confirm that use of the central difference method to compute modal curvatures greatly amplifies the measurement errors and its application leads to unreliable predictions for damage detection, even after denoising. Therefore, specialized ad hoc numerical techniques must be suitably implemented to enable structural health monitoring via modal curvature changes. In this study, the Savitzky-Golay filter (also referred to as least-square smoothing filter) is considered for the numerical differentiation of noisy data. Numerical and experimental results show that this filter is effective for the reliable computation of modal curvature changes in plate structures due to defects and/or damages

POWER SYSTEMS OPERATION IMPROVEMENT CONSIDERING LOSS MINIMIZATION AND VOLTAGE STABILITY ENHANCEMENT

The challenge of energy and power losses during electrical energy transmission from generation plants to users is a major problem that cannot be over-emphasized. These Losses are inevitable because they are inherent in the conduction of electrical energy through physical means but can be minimized. This paper presents a VSC-PSO method for optimizing the power system operation by simultaneously minimizing the loss and enhancing the voltage stability which are the objective functions. The optimal power flow (OPF) was performed on IEEE 30-bus system with Newton Raphson algorithm implemented in MATLAB simulation software. The simulation results showed that the VSC-PSO approach performed more excellently with concurrent consideration of line loss reduction and voltage stability improvement when compared with other methods in literatur

Distribution, prevalence, and severity of damages caused by nematodes on yam (Dioscorea rotundata) in NIssathme30igeria

Nigeria is the main yam-growing country of the world. In the country, various plant-parasitic nematodes have been reported constraining yam production and the storability of tubers. This study established the damage level of nematodes on white yam tubers (Dioscorea rotundata) across the major production areas in the country for management purposes. Incidence and severity of symptoms (cracking, dry rot, and galling) associated with nematodes were assessed on 1,114 yam heaps (181 vendors) from 23 markets and on 2,502 tubers from 26 farmer storage areas (yam barns) in the Humid Forest (HF), Derived Savanna (DS) and Southern Guinea Savanna (SGS) agro-ecological zones (AEZ). On yam heaps, the symptom incidence averaged 55%, 35%, and 6% for galls, dry rot, and for cracks, respectively. Only the incidence of dry rot was significantly different (P<0.0001) across the AEZ. On yam tubers, the incidence averaged 24%, 8%, and 2% for galls, dry rot, and for cracks, respectively. The incidence for galls was higher in the SGS than in the DS (P=0.0018) whereas the incidence of cracks was higher in the DS than in the SGS (P=0.0080). The actual values of symptom severity were, in general, low in the AEZ compared with the predicted values except for dry rot. A significant positive correlation was found between galls and Meloidogyne and between dry rot and Scutellonema. Pratylenchus was also recovered from a few yam tubers; however, no link with symptoms on yam tubers could be established. Vendors and farmers, based on the answers from a questionnaire, were very familiar with nematode symptoms on yam tubers, but awareness of nematodes was low. This study shows that Meloidogyne and Scutellonema are the major nematode constraints to yam production in the three AEZ of Nigeria and calls for effective yam nematode management in Nigeria and in other yam-producing countries

Comparative Analysis of Production Efficiency of Government-Assisted and Unassisted Pig Farmers in Lagos State

This study comparatively examined the efficiency of pig production among government-assisted and non-assisted farmers in Lagos State, Southwest, Nigeria. The study was based on primary data obtained in a cross-section survey of 120 pig farmers, 60 each drawn purposively from among the government-assisted (GAPF) and unassisted pig farmers (UAPF) in the state. The data were analysed by descriptive, budgetary and econometric (Stochastic Production Frontier) methods. The study revealed that, most of the pig farmers (67.7% of GAPF and 95.0% of UAPF) are men. Majority of the pig farmers (65.0% of GAPF and 55.0% of UAPF) are within 30 - 50 years age bracket; with as much as 83.3% of GAPF and 60.0% of UAPF, having no more than six years of experience in pig farming. However, most (95.0% of GAPF and 75.0% of UAPF) of the pig farmers had some tertiary education. Budgetary analysis revealed that an average GAPF incurred a total cost of N987,682 in producing N1,360,050 worth of pigs with a net farm income of N372,368 yielding 33.67% rate of returns on their investment during the 2008/2009 production season. His UAPF counterpart incurred a total cost of N727,860 in producing N938,000 worth of pigs with a net farm income of N210,140 yielding 31.73% rate of returns on during the same production season. The technical, allocative and overall economic efficiency estimates computed based on estimated Stochastic Production and Conditional Revenue Frontier models of the two categories of pig farmers revealed that GAPF are generally more efficient (with mean technical, allocative and overall economic efficiency index of 0.66, 0.68 and 0.48, respectively) than their UAPF counterparts (with mean technical, allocative and overall economic efficiency index of 0.53, 0.60 and 0.35, respectively). The differences in the production efficiency of the two categories of farms were found to be as a result of the institutional and infrastructural support received by GAPF which is not available to the UAPF. &nbsp

Epidemiological profile of the Ebola virus disease outbreak in Nigeria, July-September 2014

Introduction: In July 2014, Nigeria experienced an outbreak of Ebola virus disease following the introduction of the disease by an ill Liberian Traveler. The Government of Nigeria with the support of Technical and Development Partners responded quickly and effectively to contain the outbreak. The epidemiological profile of the outbreak that majorly affected two States in the country in terms of person, place and time characteristics of the cases identified is hereby described. Methods: Using field  investigation technique, all confirmed and probable cases were identified, line-listed and analysed using Microsoft Excel 2007 by persons, time and place. Results: A total of 20 confirmed and probable cases; 16 in Lagos (including the index case from Liberia) and 4 in Port Harcourt were  identified. The mean age was 39.5 ± 12.4 years with over 40% within the age group 30-39 years. The most frequent exposure type was direct physical contact in 70% of all cases and 73% among health care workers. The total case-fatality was 40%; higher among healthcare workers (46%) compared with non-healthcare workers (22%). The epidemic curve initially shows a typical common source outbreak, followed by a propagated pattern. Conclusion: Investigation revealed the size and spread of the outbreak and provided information on the characteristics of persons, time and place. Enhanced surveillance measures, including contact tracing and follow-up proved very useful in early case detection and containment of the outbreak