Placement of Distributed Generation and Shunt Capacitor in Distribution Network using Cuckoo Search Algorithm

This work aims at reduction in active and reactive power loss reduction in distribution networks as well as to improve the voltage stability of the networks. Optimum Distributed Generation (DG) placement and sizing is carried out in conjunction with shunt capacitor placement and sizing to determine the appropriate sizes of DG units and Capacitor banks to be placed in the networks so as not to violate certain constraints. The optimal sizes of the DG units and capacitor banks were obtained on application of a Cuckoo Search Optimization Algorithm while computations for Voltage stability was performed using the Voltage Stability Index (VSI). The obtained optimal sizes of DG units and Capacitors were individually and simultaneously placed on the distribution networks to ascertain the behaviour of the networks prior to and after their placements. The performance factors considered are power loss and voltage stability. A comparison of these performance factors under separate and simultaneous placement method was demonstrated using IEEE 33 and 69 test buses. Result show that power loss (active and reactive) reduced by 63.29% and 59.38% respectively for 33 bus system, with a 74.29% and 79.19% reduction on 69 bus system. Voltage stability also increased by 7.89% and 3.79% respectively for 33 and 69 bus system relative to values obtained for base case and separate DG and shunt capacitor placement. Keywords: Distributed generation, shunt capacitor, Cuckoo Search Algorithm (CSA), power loss and voltage stability

Household Waste Disposal Laws in the Federal Republic of Nigeria

This capstone analyzes the public health problem of a lack of waste disposal and trash collection in major cities in Nigeria. It describes the waste disposal problem and how it affects the health of the environment, as well as the magnitude of the problem. Then, the capstone investigates the land use laws in Nigeria that address or should address the issue of lacking waste disposal. Finally, the capstone explores feasible policy interventions to remedy the negative effects of inadequate waste disposal in Nigeria

The role of biofortification in the reduction of micronutrient food insecurity in developing countries

Micronutrient malnutrition is a global public health problem, especially in developing countries. Hunger and starvation which are causative agents of malnutrition are occasioned by poor food supply and low income purchasing power for the expensive animal sources of micronutrients. Access to adequate, safe and nutritious food required for a healthy and active life by all people at all times is limited, resulting in micronutrient food insecurity. The quantity and quality of food available for consumption to people determine their micronutrient security level. Inadequate quantity and quality of food available for consumption are causative agents for macronutrient and micronutrient deficiencies. Bio-fortification is an emerging method to increase the micronutrient values of crops in order to eradicate hidden hunger in developing nations. This paper therefore describes the contribution of biofortification in fighting micronutrient malnutrition in developing countries.Keywords: Micronutrient food insecurity, biofortification, developing nations, Micronutrients.African Journal of Biotechnology Vol. 12(37), pp. 5559-556

Ameliorative effect of hydroalcoholic extracts of Nigella sativa seed against CCl4-induced acute liver injury in rats

Objective:  The aim of this study is to investigate the ameliorative effect of hydroalcoholic extract of Nigella sativa (HANS) against CCl4-induced hepatotoxicity in albino rats. Methods: Twenty five (25) albino rats, with average weight (105±5g), were randomly grouped into five groups: A-E, of five (5) rats per group. Group A rats served as normal control, Group B (Negative Control) received intraperitoneal administration of carbon tetrachloride CCl₄ (0.4ml/kg, i.p.) only, Group C received CCl₄ and low dose HANS (400mg/kg, oral), Group D received CCl₄ and high dose HANS (800mg/kg, oral), and Group E (Positive control), received CCl₄ and Vitamin C (200mg/kg, oral), for 3 days. Hepatotoxicity was assessed by measuring serum levels of total bilirubin, alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) using standard methods.  Histopathological analysis of the liver was also carried out. Results: The extracts significantly stablized biochemical markers of hepatic injury, and preserved the histoarchitecture of the liver tissues against CCl4 damage. The protective effect was not dose-dependent, as low dose HANS (400mg/kg), showed better protection than the high dose HANS (800mg/kg). Conclusion: Hydroalcoholic extracts of Nigella sativa has antihepatotoxic effects. Keywords: carbon tetrachloride, hepatotoxicity, medicinal plants, Nigella sativa, hydroalcoholic extrac

Motivational Strategies and Possible Influence on Secondary School Teachers’ Teaching Performance

This study investigated the influence of motivational strategies on teachers’ teaching performance in public secondary schools in Uyo – Urban, Akwa Ibom State. One hypothesis was formed to guide the study and Expo Facto design was adopted for the study. A sample of three hundred and sixty (360) teachers were randomly selected from the population of all the secondary school teachers in the 18 public schools in the Area. A questionnaire based on four point likert-type scale was developed and administered to the 360 teachers. The data collected were subjected to statistical analyses using ANOVA. The test yielded significant influence of motivational strategies on teachers’ work performance. Based on the findings, recommendations were made.KEY WORDS: Motivational Strategies, Teaching Performance

Evaluation of gully erosion sites inselected rainforest and derived savannah ecosystem in Abia State, south east Nigeria

A study of gully erosion sites in selected Rainforest and derived savannah ecosystem was undertaking. Two single factor experiments in Randomized Complete Block Design (RCBD) with three replications were utilized separately to determine the dimensions of gullies in erosion sites. Result revealed that gully dimension in rainforest area of Abia State were highest in length in Ahiaeke Ntigbu at 1436.67m and lowest in Ossah Ibeku at 400m, width were highest in Amigbo Ubakala at 52m and lowest at 30m, depth were highest inAmigbo Ubakala at 31.67m and lowest in Ossah Ibeku at 16m. In derived savannah were seen highest in lentgh in Oruruala Amayi at 1450m and lowest in Amaekpu at 440m,width were highest in Oruruala Amayi at 92m and lowest in Akanu at 31.67m and depth were highest Oruruala Amayiin 33.33m and lowest in Akanu at 18.33m. Result of the study revealed gully erosion are more active in derived savannah area than the rainforest area of Abia State due to the type of soil in the region. Observation revealed that soil erosion in some communities was aggravated by human activities, such as deforestation and bush burning/removal of vegetation cover, mining activities, urban development and sand excavation. This problem is affecting the development because infrastructures such as houses, roads and many others are being destroyed yearly and this in turn constitutes an environmental menace. The services of competent professionals for design, construction and supervision of erosion control and soil conservation measures should be ensured and utilized.Keywords: Soil degradation, Soil erosion, rainforest, derived savanna

Extracellular Calcium and Induction of Uterine Muscle Contraction by Aqueous Ethanolic Leaf Extract of Mucuna pruriens

Calcium (Ca2+) serves as an essential signaling molecule in biological systems, regulating a wide range of cellular processes of which uterine smooth muscle contraction is among. The present study was designed to evaluate the involvement of Ca2+ on isolated uterine muscle contraction induced by aqueous ethanolic leaf extract of Mucuna pruriens (M. pruriens). Uterine muscle contraction induced by the extract was concentration-dependent and was completely abolished (100%; P<0.05) in nominally Ca2+ -free physiological salt solution and in solutions containing (EGTA 1.5 mmol), lanthanium chloride (1.5 and 3 mmol), caffeine (3and 4.4 mmol) and verapamil (0.007-0.14 μmol). It is concluded that the inability of the extract to produce contractions in Ca2+ -free media, indicates that it lacks the ability to mobilize calcium from intracellular storage sites. Hence, its uterine stimulatory property is therefore solely dependent on extracellular Ca2+. Keywords: Calcium, Mucuna pruriens, Uterus, Contraction

SIMULATION AND CONTROL OF A REACTIVE DISTILLATION COLUMN FOR THE HYDROGENATION OF BENZENE IN A REFORMATE STREAM

The Dynamic models of an N stage reactive distillation column for the hydrogenation of benzene in a reformate feed was developed. The developed models were simulated to obtain optimum number of trays (74), a benzene mass fraction in the bottom product (0.0056) and feed entry point (24th tray) as process conditions of the column. The developed models were tested using industrial plant data from Charkrabaty, (2004) and a benzene mass fraction from the first tray (bottom) of 0.00589 (0.0061 vol. %) was obtained compared to 0.00599 (.0062 vol. %) obtained by Charkrabaty, (2004). Open loop response of the column to step changes (±) in disturbances such as feed composition, flowrate and temperature showed fluctuations and linear response/relationship between the outputs (re-boiler mass fraction of benzene, condenser liquid hold-up, re-boiler liquid holdup) and the disturbances with stability attained over a long time. Column control was studied by performing Closed loop response of the column to a multiple input-multiple output (MIMO) feedback control configuration with proportional controllers using the re-boiler heat duty, reflux and distillate flow rates as manipulated variables. Results showed a great reduction in fluctuations with stability attained in 30 and 900 seconds respectively for the condenser liquid hold up and re-boiler benzene mass fraction compared to 8750 seconds obtained for both variables in the open loop response. Keywords: Reactive Distillation model, Hydrogenation of reformate, open and close loop response