A Review of Optimization Approach to Power Flow Tracing in a Deregulated Power System

Power Flow Tracing (PFT) is known to be the best method in the allocation of charges to users of transmission systems, generators and loads, in a deregulated environment. The optimization approach to PFT produced better results than other methods because it considers the physical power flow results and electrical constraints of the system. A brief review of the optimal power flow concept, PFT techniques, and the deterministic and non-deterministic optimization methods applied to PFT are presented. The paper also highlighted the future trends of hybrid optimization approach to PFT. It is recommended that more research work should be directed on the hybrid optimization methods to solve PFT problems

Analysis of Conduct and Performance of Dried Fish Market in Maiduguri Metropolis of Borno State, Nigeria

The study analyzed conduct and performance of dried fish markets in Maiduguri Metropolis of Borno State, Nigeria. Data were obtained using structured questionnaire. Three (3) major dried fish markets were purposely selected out of the seven (7) markets in the study area to reflect areas where dried fish is predominantly sold. A total of 100 respondents from the three (3) markets were randomly selected for the study. Descriptive statistics and budgetary techniques were used as analytical tools. The finding of the study reveals that (44.82%) and (33.33%) were obtained as market margin from sales of Grade C and Grade A dried fish respectively. The result of marketing cost and returns also reveals that capital invested constitutes (96.08%) of the total fixed cost, while transportation accounts for (30.55%) of the total variable cost. The result of market return (net returns) reveals that N25, 013,440.04 was obtained as net returns per week. The finding on marketing efficiency reveals (67.33%) was obtained per cartoons of dried fish sold. The result further indicates the efficiency ratio of 95.54 which is positive. The result of the market conduct reveals that about (40%) of the marketers get information on market situation through personal contact, (72%) price haggling, while (56%) said prices were set by both the sellers and the agents. It was recommended that local fish marketers should be organized into cooperative groups and government should adequately provide infrastructural facilities such as good roads and market facilities to dried fish marketers in the study area. Key words: Market Conduct, Market Performance, Dried Fish Market, Borno State,  Nigeri

Analysis of Marketing Channel and Market Structure of Dried Fish in Maiduguri Metropolis of Borno State, Nigeria

The study examined channel and market structure of dried fish in Maiduguri Metropolis of Borno State, Nigeria. Data were obtained using structured questionnaire. Three (3) major dried fish markets were purposely selected out of the seven (7) markets in the study area to reflect areas where dried fish sellers are predominantly found. A total of 100 respondents from the three (3) markets were randomly selected for the study. Descriptive statistics, Ginni coefficient, least square simple regression and budgetary techniques were used as analytical tools. The result reveals that marketing channel is divided into wholesalers and retailers of fresh and processed fish (dried fish). The finding also indicates that the values of Ginni coefficient were (0.5478) and (0.5252) for wholesalers and retailers, respectively. And the dried fish market had non competitive behaviour with monopolistic nature. The finding also reveals that (82%) of the marketers engaged in marketing Grade C dried fish products. The result of economies of scale reveals that the coefficient of wholesalers was (-0.005) while that of retailers was (-0.741) and are all negative but, statistically significant at 1% and 5%, respectively. It was recommended that local dried fish marketers should be organized into cooperative groups and government should provide adequate infrastructural facilities such as good road net work and market facilities. Keywords: Marketing channel, Market Structure, Dried fish, Borno State, Nigeria

A case of pericardial effusion: Aid of bedside ultrasound in clinical decision making

Background: In life-threatening conditions, such as cardiac tamponade, we need to recognize signs of impending decompensation in a timely manner. Point of care ultrasound is non-invasive and is readily available, particularly in a resource limited setting. In this case, we present a patient with worsening pericardial effusion and the importance of bedside cardiac ultrasound. Case presentation: A 76-year-old male with stage IV adenocarcinoma of the lung was admitted for worsening dysphagia for 3 days and decreased oral intake. He was normotensive but was tachycardic with muffled heart sounds. CT of the chest demonstrated a significant pericardial effusion. Bedside ultrasound to evaluate the extent of pericardial effusion revealed significant circumferential effusion, right systolic atrial collapse, and non-variable IVC, signs of pre-tamponade physiology. Given these findings, cardiology was emergently consulted who recommended transfer to a higher level of care facility. Thus, point of care ultrasound helped in making an immediate decision prior to clinical decompensation of the patient. Conclusion: Point of care ultrasound can help in making critical decisions in resource-limited settings. In this patient, a large effusion with pre-tamponade physiology was identified on bedside ultrasound. Early recognition during bedside ultrasound can help reach a diagnosis before clinical deterioration. Our case highlights the importance of point of care ultrasound as a tool to reinforce critical thinking and help expedite rational decision-making processes

Hybrid algorithm for NARX network parameters' determination using differential evolution and genetic algorithm

A hybrid optimization algorithm using Differential Evolution (DE) and Genetic Algorithm (GA) is proposed in this study to address the problem of network parameters determination associated with the Nonlinear Autoregressive with eXogenous inputs Network (NARX-network). The proposed algorithm involves a two level optimization scheme to search for both optimal network architecture and weights. The DE at the upper level is formulated as combinatorial optimization to search for the network architecture while the associated network weights that minimize the prediction error is provided by the GA at the lower level. The performance of the algorithm is evaluated on identification of a laboratory rotary motion system. The system identification results show the effectiveness of the proposed algorithm for nonparametric model development

PRELIMINARY STUDIES ON RED BELLY TILAPIA COPTODON ZILLII CAUGHT FROM OYAN DAM, OGUN STATE, NIGERIA

The study was carried out on the biological aspect of Redbelly Tilapia, Coptodon zillii collected from Oyan Lake, Abeokuta North Local Government Area, Ogun State, Nigeria, with the aim of contributing to the baseline data for carrying out further studies on its ecology, conservation and development. A total of two hundred and fifty four fish (254) specimens were caught from the Ibaro landing site of the Lake between March and July, 2015. The total length (cm), standard length (cm), head length (cm), body width (cm), body depth (cm), snout length (cm), eye diameter (cm) and body weight (g) were measured. The stomach content was also assessed in order to determine its food and feeding habit. The mean total-length, standard-length, head-length, eye-diameter, snout-length, body-depth, body-width and body-weight during the study were 10.98±0.61cm, 8.56±0.14cm, 2.5±0.08cm, 3.67±0.15cm, 1.52±0.11cm,1.37±0.17cm, 4.05±0.07cm, 34.25±3.02g respectively and their ranges were (4.5-18.7cm), (3.2-15.2cm), (1.1-5.8cm), (2.0-6.8cm), (0.8-3.0cm), (1.1-4.8cm), (1.4-7.3cm) and (6.0-132.0g). A negative allometric (b<3) growth pattern was observed for the stock. The meristic characteristics of C. zillii were (DFR) XIV 10 – XVI 14; PVR, AFR III 8 –III 9; PFR 10 – 13 respectively. Stomach analysis showed that diatoms were the most abundant food items in the diet of C. zillii numerically, 29.98%, while desmids were the most abundant food items in terms of frequency occurrence, 27.82%. This study concluded that C. zillii is not morphometrically and meristically different from the already classified from previous studies. Also, C. zillii thrives well on available plants and detritus.   &nbsp

Origin and residence time of groundwater in the shallow coastal aquifer of eastern Dahomey Basin, Southwestern Nigeria, using δ18O and δD isotopes

This study employed stable isotopes of δ18O and δ2H in conjunction with other hydrological parameters to understand the origin, inferred residence time, and seasonal effect of groundwater in the shallow aquifers of the eastern Dahomey Basin. A total of 230 groundwater samples (97 in the wet season and 133 in the dry season) were collected from the borehole and shallow aquifer between May 2017 and April 2018. Groundwater analysis included major ions and δ18O and δ2H, isotopes data in precipitation from three selected Global Network of Isotope in Precipitation (GNIP) stations across West Africa, Douala in Cameroon, Cotonou in Republic of Benin, and Kano in Nigeria were used in comparative analysis. Results of the hydrochemical model revealed Ca-HCO3 and Na-Cl as dominant water types with other mixing water types such as Ca–SO4, Ca–Cl, Na–SO4, and K–Mg–HCO3, which characterised early stage of groundwater transformation as it infiltrates through vadose zone into the aquifer. δ18O and δ2H precipitation data from the three stations plotted along with the groundwater samples indicate recent meteoric water origin, with little effect of evaporation during the dry season. The plot of Total Dissolved Solids (TDS) against δ18O showed clustering of the water samples between the recharge and the evaporation zone with dry season samples trending towards increased TDS, which is an indication of the subtle effect of evaporation during this period. Tracing groundwater types along the flow paths within the basin is problematic and attributed to the heterogeneity of the aquifer with anthropogenic influences. Moreover, a comparison of the δ18O and δ2H isotopic compositions of groundwater and precipitation in the three selected stations, with their respective deuterium excess (D-excess) values established low evapotranspiration induced isotope enrichment, which could be due to higher precipitation and humidity in the region resulting in low isotope fractionation; hence, little effect of seasonal variations. The study, therefore, suggested groundwater recharge in the shallow aquifer in the eastern Dahomey Basin is of meteoric origin with a short residence time of water flows from soils through the vadose zone to the aquifers

HELMET USE AS A SAFETY TOOL AMONG MOTORCYCLE RIDERS IN IBADAN, OYO STATE, NIGERIA

This work studies helmets use as a safety tool among motorcycle riders in Ibadan, Oyo state, Nigeria. The instrument of data collection was a structured interviewer administered questionnaire on 400 motorcycle riders at Mokola and Sango areas, Ibadan. 330 responses were obtained to give a return rate of 82.5%. The analysis of the results showed that the frequency of helmet use in the study areas is 77.6% and that of non-user is 22.4%. 80% of the respondents felt that helmet use should be mandatory while only 20% felt that it should be at the discretion of riders. 150 (45.5%) respondents have ever been involved in motorcycle accidents out of which 94 (62.7%) were involved in head injury accidents. Up to 86 (91.5%) of these were involved in head injury accident before the introduction of legislation for compulsory crash helmet wear by motorcyclists in Nigeria while only 8(8.5%) were involved in the accident after the legislation of the law. This shows a decrease in head injury accidents after implementation of crash helmet law. Hence, there is need to strengthen existing legal enforcement of helmet use and ensure the availability of quality helmet to non-user both the commercial and private motorcyclists

Response of Guinea Grass (\u3cem\u3ePanicum maximum\u3c/em\u3e Jacq) to Application of Cow Dung in South West Nigeria

The yield of forage species from the world\u27s grazing land is limited by poor soil and unproductive species (Jones & Wild, 1975; Cooke, 1982). The use of manure on pasture land not only represents a low cost disposal method but also a means of recycling nutrients for plant growth and counteracting the decreasing organic matter content in most agricultural soils. In agro-pastoral production systems, the interaction between crops and livestock is important. Manures are used mainly to complement inorganic fertiliser in the production of food crops. There is a dearth of information on the response of pasture grass to application of cow dung and so the response of two Panicum maximum ecotypes to cow dung was evaluate