ASSESSMENT OF JEBBA HYDROPOWER DAM OPERATION FOR IMPROVED ENERGY PRODUCTION AND FLOOD MANAGEMENT

One of the reservoir management options for flood moderation and energy production is the operation of Hydropower Dams to protect people and their socio-economic activities in flood plain areas. This study focuses on assessing Jebba Hydropower Dam Operation for improved energy production and flood management. Available Data for 27-year period (1984 - 2011) such as inflow, elevation, turbine release, generating head, energy generation, tailrace water level and plant coefficient was obtained from Jebba Dam Station. The present reservoir-operating rule was investigated using statistical analysis to model the operation of the multi-purpose reservoir. Statistical tests carried out in accordance with standard procedure include chi-square (χ2), probability plot coefficient of correlation (r), and coefficient of determination (R2). The results show that the optimal solution at operating performance of 50% reservoir inflow reliability has the total annual energy generation of 42105.63MWH with adequate water supply for downstream users and for irrigation throughout the year with annual optimal evaporation losses averaged at 58.16Mm3. Average optimal energy generation obtained is 19% of the observed energy generation but with adequate water supply for downstream users and for irrigation throughout the year. It is, therefore, essential to develop a decision-making framework capable of handling the conflicting demand

Adaptive dual-comb spectroscopy in the green region

Dual-comb spectroscopy is extended to the visible spectral range with a set-up based on two frequency-doubled femtosecond ytterbium-doped fiber lasers. The dense rovibronic spectrum of iodine around 19240 cm-1 is recorded within 12 ms at Doppler-limited resolution with a simple scheme that only uses free-running femtosecond lasers

Analysis of Independence of Available Infrastructure on Geographical Location of Public Secondary Schools in Ondo State, Nigeria

This paper has attempted to study the availability of infrastructural facilities in public secondary schools in Ondo State, Nigeria. Six local government areas (LGAs) were randomly selected with due consideration to the geo-political set-up of the State. Quantitative methods of analysis that were used include both descriptive and inferential statistics. The descriptive statistical techniques were tabular presentation and bar chart while the inferential statistical technique applied is chi-square analysis. The inferential statistics revealed that enrollment of students in secondary schools depends on gender and on Local Government Area. Also, the level of equipping of laboratories, availability of information technology facilities,  portable water supply and supply of electricity depend on Local Government Area while availability of library in secondary schools is independent of Local Government Area. Conclusively, much still need to be done in the area of infrastructural development in public primary and secondary schools in Ondo State towards the achievement of the vision 20: 2020 goal of Nigeria as one of the 20 most developed economy of the world in terms of education. Keywords:  education, infrastructure, information technology, chi-square, enrollment

Impact of Credit Demand on the Productivity of Rice Farmers in South West Nigeria

Employing cross-sectional data from 360 rice farmers selected from three states in South West Nigeria, the study analyzes the impact of credit demand on the productivity of rice farmers. An Endogenous Switching Regression Model (ESRM) that accounts for both heterogeneity and sample selection biases were used to estimate the impact of credit demand on rice productivity in South West Nigeria. In addition, a Tobit regression model was employed to measure the level of participation of rice farmers in the credit market. The result of the first stage (probit model) of the ESRM revealed that household assets, access to service, climate variables, regional variables, and transaction cost are statistically significant in influencing farmers’ credit demand decision. The results of the second stage of the ESRM indicate factors such as household assets and access to service were statistically significant in explaining variations in rice productivity among participants and non-participants in the credit market. Furthermore, the results of the Tobit model showed that the farmers’ location income from rice farming experience, interest rate, and distance to the source of credit are statistically significant determinants of the amount of credit received. These findings suggest that facilitating farmers’ access to credit will improve rice productivity. Therefore, it is imperative for government and development partner to work together in order to improve the conditions for suitable agricultural credit access to rice farmers, especially a review of interest rates. A necessary addition should be developed to the assistance already being provided under Nigeria Incentive-Based Risk Sharing System for Agricultural Lending (NIRSAL) in the form of loan guarantees and other risk-sharing incentives, such as a regulatory environment that supports the modern contractual obligations that are characteristic of well-functioning agricultural financing. This would not only contribute to the intensification of rice production in Nigeria to meet its increasing rice demand, but also improve rice farmers’ productivity and their households’ incomes

Nano-mechanical properties and structural of a 3D-printed biodegradable biomimetic micro air vehicle wing

The biomimetic micro air vehicles (BMAV) are unmanned, micro-scaled aircraft that are bio-inspired from flying organisms to achieve the lift and thrust by flapping their wings. The main objectives of this study are to design a BMAV wing (inspired from the dragonfly) and analyse its nano-mechanical properties. In order to gain insights into the flight mechanics of dragonfly, reverse engineering methods were used to establish three-dimensional geometrical models of the dragonfly wings, so we can make a comparative analysis. Then mechanical test of the real dragonfly wings was performed to provide experimental parameter values for mechanical models in terms of nano-hardness and elastic modulus. The mechanical properties of wings were measured by nanoindentre. Finally, a simplified model was designed and the dragonfly-like wing frame structure was bio-mimicked and fabricated using a 3D printer. Then mechanical test of the BMAV wings was performed to analyse and compare the wings under a variety of simplified load regimes that are concentrated force, uniform line-load and a torque. This work opened up the possibility towards developing an engineering basis for the biomimetic design of BMAV wings

Abundance and Distribution of Large Mammals in the Upper Ogun Game Reserve, Oyo State, Nigeria

Three different methods for estimating wild animal populations were used to assess the density of different species in a game reserve in the Sahel region of Nigeria. Hunting for bushmeat by local communities living around the reserve was identified as one of the threats to wildlife populations. Bushmeat was an essential resource for communities around the reserve

Abundance and Distribution of Large Mammals in the Upper Ogun Game Reserve, Oyo State, Nigeria

In this study, three indirect methods [counts of animal droppings, footprints, and tracks) were used as indices to estimate the abundance and distribution of large mammals in the Upper Ogun Game Reserve, which is located in a typical Southern Guinea savanna zone of Nigeria. Thirteen animal species were recorded; kob, bushbuck, hartebeest, roan antelope and duicker were the most abundant. The distribution of large mammals appears to be controlled by several factors: accessibility to the River Ogun [the main source of water in the reserve), availability of food and cover, and the extent of illegal hunting. An analysis of questionnaires distributed to various people living in villages around the reserve revealed that these people depend heavily on bushmeat for their animal protein requirements. They also use other wildlife products to meet their economic, social, and cultural needs. It is recommended that adequate protection should be accorded to the game reserve for at least 5 years. After that time, the area could be opened up to tourism, and controlled hunting could be permitted in the buffer zone around the reserve

Two case reports on Mandibular metastases

Metastatic tumours of the oral cavity are not common. The most common site for bone metastases in the head and neck region is the mandible. Metastatic lesion of the mandible most commonly originate from the lungs in men and breast in women, and these lesions (or tumours) usually are carcinomas rather than sarcomas. We report two cases of metastatic lesions in the mandible: (1) A 19year old male with right mandibular swelling and a nodular swelling in the distal two–third of the right tibia. Radiograghs revealed sclerotic lesion with a sunburst appearance in both the jaw and tibia. Histology of the jaw lesion confirmed a metastatic osteosarcoma of the mandible. (2) A 51year old female with a right mandibular swelling with associated swelling in the anterior neck, right shoulder and right parietal region of the skull. Computerised tomography scan (CT) of the jaws showed an osteolytic lesion of the right mandible. CT scan of the brain also showed a large lytic lesion seen in the posterior aspect of the right parietal bone. Histology of the jaw mass confirmed a metastatic follicular carcinoma from the thyroid. Mandibular metastasis may be the first presenting feature of underlying occult malignancy of another primary site. Therefore, clinicians should maintain a high level of suspicion while evaluating patients with a history of cancer presenting with oral lesions. Keywords: metastatic tumours, mandible, tibia, thyroi

Chrysophyllum Albidum Accelerates Delayed Gastric Ulcer Healing in Rats Through Oxidative Stress Reversal and Proton Pump Inhibition

Background: Chrysophyllum albidum has been documented to exert its gastric ulcer (GU) healing activities by modulating blood inflammatory mediators, however, other probable in-vivo underlying mechanisms are still vague which this study sought to investigate.Materials and Methods: Male Wistar rats (120-130g) divided into 9 groups (n=15 for groups I-VII; n=5 for groups VIII & IX) viz: Groups I- positive control (DUnA); II and III–250 and 500mg/kg methanolic extract of C. albidum (MeCaB) bark respectively; IV, V and VI-100mg/kg fractions A, B and C respectively; VII–30mg/kg omeprazole; VIII-ulcerated untreated (baseline), IX-negative control. Chronic GU was induced experimentally and delayed using indomethacin with 14 days simultaneous drug treatment. Gastric ulcer score, mucin content, antioxidant and proton pump activities were evaluated by days 3, 7 and 14 of treatment. Data were expressed as Mean+SEM and P<0.05 was significant.Results: C. albidum and fractions treated groups significantly decreased gastric ulcer scores and lipid peroxidation compared with DUnA. Negative control, C. albidum and fraction treated groups significantly increased superoxide dismutase, catalase, glutathione levels and mucin content compared with DUnA group by days 3 and 7. C. albidum, Negative and baseline control groups significantly decreased H+K+ATPase activities compared with DUnA by day14.Conclusion: C. albidum and its fractions facilitated the healing of gastric ulcer, probably by enhanced antioxidant levels, mucin content and decreased gastric H+K+ATPase activity. Keywords: C. albidum and chromatographic fractions, gastric ulcer healing, mucin , antioxidant, H+/K+ATPase pump

Prediction of dry ice mass for firefighting robot actuation

The limitation in the performance of electric actuated firefighting robots in hightemperature fire environment has led to research on the alternative propulsion system for the mobility of firefighting robots in such environment. Capitalizing on the limitations of these electric actuators we suggested a gas-actuated propulsion system in our earlier study. The propulsion system is made up of a pneumatic motor as the actuator (for the robot) and carbon dioxide gas (self-generated from dry ice) as the power source. To satisfy the consumption requirement (9cfm) of the motor for efficient actuation of the robot in the fire environment, the volume of carbon dioxide gas, as well as the corresponding mass of the dry ice that will produce the required volume for powering and actuation of the robot, must be determined. This article, therefore, presents the computational analysis to predict the volumetric requirement and the dry ice mass sufficient to power a carbon dioxide gas propelled autonomous firefighting robot in a high-temperature environment. The governing equation of the sublimation of dry ice to carbon dioxide is established. An operating time of 2105.53s and operating pressure ranges from 137.9kPa to 482.65kPa were achieved following the consumption rate of the motor. Thus, 8.85m3 is computed as the volume requirement of the CAFFR while the corresponding dry ice mass for the CAFFR actuation ranges from 21.67kg to 75.83kg depending on the operating pressure