Voltage Stability Assessment Using Modal Analysis

Voltage instability incidence has of recent been a major threat to the optimum operation of a modern power system due to continuous increase in load demand and insufficient reactive power to meet the demand. Thus, it becomes imperative to carry out voltage stability assessment in a power system to prevent the catastrophe of voltage collapse. This work present voltage stability assessment using a technique based on modal analysis of the reduced Jacobian. The modal analysis method makes use of the power system Jacobian matrix to find the eigenvalues essential for the evaluation of the voltage stability of a power system. The bus with the smallest value of eigenvalue is taken as the critical mode of the system. The participation factor (PF) of each load node is then determined to evaluate the bus which contributes most to the critical mode identified. The bus with the highest value of PF is taken as the critical bus of the system. The effectiveness of the methodology presented is tested on the IEEE 30 bus power system. Result obtained shows that voltage stability assessment using modal analysis method could be of a great importance to power system operators in the identification of critical nodes that are liable to voltage collapse in power system. Keywords: Power flow, modal analysis, power system, voltage stability, participation facto

Assessment of Compliance with Development Regulations in Abeokuta-West Zonal Planning Area, Nigeria

Development control is a medium through which the land use is licensed for building and other purposes backed-up by planning laws and regulations. Despite the importance of development control measures in physical and environmental balancing, a series of factors still hinder its effectiveness. The paper examines the compliance with development regulations in Abeokuta-West Zonal Planning Area, Nigeria. Primary and secondary sources of data were used. A questionnaire and personal interview were both used. Multi-stage sampling method was adopted because the buildings in the planning area are numerous and spatially located. The planning area was divided into nine zones which were classified into three; from which Obada-Oko, Oke-Ata, and Bode-Olude areas were considerably selected. The number of buildings in the selected areas was 668 buildings, and 40% was used to select the sample for each area, the research then had a sample size of 267 buildings The selection of sample size was carried out systematically for the administration of questionnaires by the residents (building owners). The data collected were presented and analysed through the use of descriptive statistics. The findings indicated that 78.7% of the residents were aware of the existence of penalties for building without permission; 68.5% of the resident did not obtain a development permit, while 15.6% out of the 31.5% that obtained a development permit deviated from the approved building plan; and 58.3% of the residents were not satisfied with the procedures involved in obtaining development permit, because it is cumbersome and expensive.  Regulatory measures were recommended for the improvement of development control practice in the study area. These include the provision of the framework as a guide for physical development; effective public awareness; and enlightenment programmes. Also, various socio-economic classes (high, medium, and low classes), especially the low-income earners, should be given considerate attention in the course of policy formulation and planning implementation

Perceived Benefits of Improved Practices in Pre Harvest Tomato Production among Farmers in Afijio Local Government Area, Oyo State

This study was designed to investigate the perceived benefits of improved practices in pre-harvest tomato production among farmers in Afijio Local Government Area of Oyo State. Multistage sampling techniques were used to select respondents in the study area, with the aid of structured questionnaire. Descriptive and inferential (PPMC) statistics were used to analyze the data. Majority of the respondents (88.5%) perceived that it has lots of benefits. Also, 82.7% perceived that improved practices minimize post-harvest losses on a medium scale.  Furthermore, 85.6% perceived that improved practices minimize disease infestation on a medium scale, while 84.6% perceive it protects tomato from decaying. Also, 76.9% of the respondents perceive that improve practices helps to retain nutritional content of tomato on a medium scale.  Also, the category of the respondents that had high awareness considered the improved practices to be highly beneficial to them.  The study further concluded that the benefits derived by minority of the respondents influenced most of the respondents to have favorable perception to derivable benefits embedded in improved practices of tomato in the study area.  In addition, the result also revealed significant relationship between awareness and perceived benefits of improved practices in pre-harvest tomato production (r=0.280, p=0.004).  The study therefore recommended that the extension agents should properly train the farmers on the benefits and use of these improved practices. Adequate information should be made available to the tomato farmers on the most recent developments in tomato farming and production (pre harvest and post-harvest). The government should be able to provide adequate and glitch free loan to the farmers to enable them utilize the information and training

Gas Chromatography-Mass Spectrometric (GC-MS) Analysis of Ethanolic Extract of the Peel of Dioscorea bulbifera Linn (Air Potatoe)

The bioactive chemical compounds in the ethanolic extracts of the peel of Dioscorea bulbifera Linn, native to Nigeria was investigated and characterized using gas chromatography-mass spectrometric (GC-MS) analysis. The relatively high concentration of the phytochemicals in the peel of this tuber; saponin (32.28mg/g), terpenoid (22.90mg/g), cardiac glycoside (15.90mg/g), flavonoid (9.17mg/g), tannin (4.79mg/g) and phlobatannin (1.87mg/g), was the most attractive factors that triggered the present study. The GC-MS analysis of the ethanolic extract of the peel of D. bulbifera shows 4 prominent peaks as R-(-)-1,2-Propanediol (C3H8O2) with retention time of 6.103min and the highest peak area of 86.05%; 1-Methylhexylhydroperoxide (C7H16O2) with retention time of 42.567min and peak area of 5.57%; Cis-3-hexenyllactate (C9H16O3) with retention time of 45.395min and peak area of 5.01%; and Pyrrole (C4H5N) showed peak of 3.37% with retention time of 45.508min. Other less prominent peaks at other retention times included; 2-Nitro-Dimethylnitromethane (C3H7NO2) with retention time of 37.355min, Ethylenimine (C2H5N) with retention time of 42.665min, N-Formyl-N-Methyl-formamide (C3H5NO2) with retention time of 44.225min, and Guanidine (CH5N3) with retention 44.225min. This work which is the first-time report on the bioactive compounds in the organic crude extracts of Dioscorea bulbifera native to Nigeria, using the GC-MS, has however established the presence of quite number of chemical compounds in the peel of the tuber, to which their pharmacological activities could be attributed. The presence of these secondary metabolites in the peel of Dioscorea bulbifera, is hence, the major contributing factors behind its antimicrobial potential. Keywords: GC-MS, Dioscorea bulbifera, antimicrobial properties, bioactive compounds, ethanolic extrac

Analyses of Willingness to Practice Agriculture as Enterprise among Students of Tertiary Institutions in Ibadan, Oyo State

This study investigated willingness to practice agriculture as enterprise among students of tertiary institutions in Oyo State. A Multi-stage sampling technique was used to elicit data from 112 selected respondents in the study area. Data were collected using a well structured questionnaire and analyzed with the use of descriptive (frequency counts, percentages, and mean) and inferential statistic (Chi-square and Pearson Product Moment Correlation). The results showed that majority of the respondents were within the age range of 21-25 years, with majority males, whom were single in the study area. Furthermore, results revealed that majority of the respondents had low interest in agricultural enterprise preference and high constraint associated with respondents willingness to engage in agricultural enterprise in the study area. Majority of the respondents had positive willingness to practice agricultural enterprise in the study area. There was significant relationship between selected socio-economic characteristics of the respondents except Gender and Marital status. It is therefore recommended that government should motivate agricultural students by providing Youth Empowerment programmes and services directed to improve their willingness to engage in agricultural enterprises

Pattern of abdominal wall herniae in females: a retrospective analysis

Background: Gender differences are expected to influence the pattern and outcome of management of abdominal wall hernias. Some of these are left to speculations with few published articles on hernias in females.Objectives: To describe the clinical pattern of abdominal wall hernias in females.Method: A 5 year retrospective review.Result: There were 181 female patients with 184 hernias representing 27.9% of the total number of hernia patients operated. Mean age was 41.66±24.46 years with a bimodal peak in the 1st and 7th decades. Inguinal hernia accounted for majority (50.5%) but incisional hernia predominated in the 30-49 age group, while only inguinal and umbilical hernias were seen in the first two decades (p=0.04). There was no side predilection in the cases of inguinal hernia. There were 12 (6.6%) emergency presentations, most of which occurred in the 6th decade and above and none below 30 years (p=0.02). Umbilical (4 cases) and femoral hernias (3cases) accounted for most of these cases. Incisional hernia was the commonest cause of recurrent hernias.Conclusion: Inguinal hernia is the commonest hernia type in females followed by incisional hernias which also accounteds for most recurrent cases. Age appears to be a risk factor for developing complications.Keywords: Female, herni

Awareness of Cassava Peel Utilization Forms among Cassava Processors in Rural Communities of Southwest, Nigeria

Significant quantities of generated peels are been thrown on dumping sites in southwest, Nigeria thereby constituting a source of environmental pollution. This study assessed the awareness of cassava peel utilization forms among cassava processors in rural communities of southwest, Nigeria. Interview guide was used to elicit information from 200 cassava processors through a multistage sampling technique. Data were analyzed with both descriptive and inferential statistics. Result revealed that majority of the cassava processors were women (76.5%), married (75.0%), and members of cassava processing associations (89.5%) with 73.0% having at least primary education. The mean age and cassava processing experience were 53.01 and 22.76 years respectively. About 23.0% of the processed cassava tubers constituted peels. The study also revealed that 50% of the cassava processors discarded peels as waste, 26% sold generated peels while 24% fed the peels to their livestock. Also 93.5% of the cassava processors were not aware of any cassava peel utilization technology. Chi-square analysis revealed that significant association existed between existing practice on cassava peel utilization (χ2=17.341, p<0.05) and cassava processors’ awareness of cassava peel utilization forms. The study concluded that substantial quantity of peel been generated is discarded as waste due to lack of awareness of cassava peel utilization technologies in the study areas. The study therefore recommended that improved technologies on the utilization of cassava peel should be popularized through result demonstration among cassava processors in southwest, Nigeria

COVID-19 Pandemic: Perception, Practices and Preparedness in Nigeria

Since Coronavirus disease 19 (COVID-19) pandemic was declared a public health emergency of international concern by the World Health Organization (WHO) on the 30th of January, 2020. Nigeria, with 343 cases and 10 deaths as at April 14, 2020 is classified as one of the countries at high risk of importation of the disease from China. The ability to limit and control local transmission after importation depends on the application and execution of strict measures of detection, prevention and control. The initial response of some percentage of the population was of doubt due to the ignorance of the far-reaching effect of the virus. More than 1,700 leaders of religious groups and communities in all 36 States and FCT were therefore sensitized to increase awareness level and consequences of COVID-19 among the populace. Major response activities were initiated before the first case was reported and were upgraded within weeks after the number of cases began to rise. Based on previous experience of perception, and awareness of other viral disease outbreaks, COVID-19 infection prevention and control interventions recommended by WHO are yet to be fully entrenched in the Nigerian public health system in order to reduce the general risk of contracting SARS-CoV-2 from infected individuals. There is therefore the need to execute strict measures of detection, prevention and control and drive compliance with the Nigeria Centre for Disease Control (NCDC) and WHO guidelines in Nigeria

Mathematical investigation of normal and abnormal wound healing dynamics:local and non-local model

The movement of cells during (normal and abnormal) wound healing is the result of biomechanical interactions that combine cell responses with growth factors as well as cell-cell and cell-matrix interactions (adhesion and remodelling). It is known that cells can communicate and interact locally and non-locally with other cells inside the tissues through mechanical forces that act locally and at a distance, as well as through long non-conventional cell protrusions. In this study, we consider a non-local partial differential equation model for the interactions between fibroblasts, macrophages and the extracellular matrix (ECM) via a growth factor (TGF-β) in the context of wound healing. For the non-local interactions, we consider two types of kernels (i.e., a Gaussian kernel and a cone-shaped kernel), two types of cell-ECM adhesion functions (i.e., adhesion only to higher-density ECM vs. adhesion to higher-/lower-density ECM) and two types of cell proliferation terms (i.e., with and without decay due to overcrowding). We investigate numerically the dynamics of this non-local model, as well as the dynamics of the localised versions of this model (i.e., those obtained when the cell perception radius decreases to 0). The results suggest the following: (i) local models explain normal wound healing and non-local models could also explain abnormal wound healing (although the results are parameter-dependent); (ii) the models can explain two types of wound healing, i.e., by primary intention, when the wound margins come together from the side, and by secondary intention when the wound heals from the bottom up.</p