In this theoretical investigation, a mathematical model is developed to study the effect of multiple stenoses on flow characteristics of streaming blood through the atherosclerotic artery. The Bingham plastic fluid model of blood has been utilized in the study to represent the non-Newtonian character of blood. The geometry of the asymmetric shape of the stenosis assumed to be manifested in the arterial segment is given due consideration in the analysis. An extensive quantitative analysis is performed through numerical computations on flow resistance, wall shear stress and their variations are presented graphically for different stenotic and other rheological parameters. It is observed that the stenotic and physical parameters have considerable effect in the flow behaviour. Some important observations having medical interest on the flow of blood in the stenosed arteries are presented. The investigation bears the potential to explore a variety of information regarding some phenomenological aspects of the physiological problem. The output of the investigation may provide supplementary support to the physician in the treatment of the fatal disease.

The operational status of a hydropower dam is described as either satisfactory or unsatisfactory. The ability of existing and proposed hydropower dams to operate satisfactorily under wide range of possible future demands and hydrologic conditions is an important system characteristic that can be assessed by estimating the reliability (the probability that a system will remain in a non-failure state), resilience (the ability of a system to return to non-failure state after a failure has occurred) and vulnerability (the likely damage of a failure event) of the system. The main sources of the data and other useful information for this research were previous research works, government documents, bulletins and gazettes from hydropower related ministries, agencies and organizations. Desktop analysis was carried out to estimate the water requirement to generate power by various combinations of units at the Jebba hydroelectric dam. Linear programming was used to obtain the monthly reservoir releases that maximized annual total energy generation. Both monthly and annual simulations were carried out using the operation policies from the LP optimization algorithm and the generated inflow series. Duration of the failure event (d(j)), the total number of failure events (M) and the deficit volume of the failure event (v(j)) were obtained from the simulation processes and used to evaluate the reliability, resilience and vulnerability of the Jebba dam. The results obtained showed that the performance of Jebba hydropower dam when three or more units are in use is generally poor. The reliability obtained over the period of historical record varied from 0.024 for six units to 0.994 for one unit in use. Reliability based on the optimized operation policy was not less than 60% and was as high as77%. The resilience was 0.292 and vulnerability was 3298.19 Mm3 at 60% reliability. These results confirm that the operational status of the dam can be improved by adopting real time reservoir release policies obtained by optimization of the reservoir operation.

Groundwater is a natural resource that is of immense importance to life and its characteristics are greatly determined by the properties of the immediate geologic formations. Generally, the development of groundwater resource involves three main stages: exploration, evaluation and exploitation. This study focuses on the evaluation stage, which generally encompasses measurement of hydrologic parameters, and estimation of aquifer yield. The analysis of pumping test data collected for 17 wells spread across Kogi state was used to determine the hydraulic parameters of the aquifers within the study area. Transmissivity values ranged from 0.751 – 8.92 m2/day, hydraulic conductivity ranged from 0.0867–1.33 m/day, pumping rates ranged from 1.13 – 8 l/s, while the borehole depths ranged from 11.3 – 202 m. Groundwater maps of the hydraulic parameters were also developed for the study area. These results show that the aquifers within the study area can provide between 5000 to 40,000 litres of water per day. The aquifers can therefore serve as sustainable and dependable sources of water all year round with sufficient water to meet the domestic needs in many small rural communities of Kogi state.

A single cylinder, 4-stroke spark ignition engine type Prodit; fueled with supplementary Natural gas to liquefied petroleum gas (LPG) was used in this paper to investigate the emitted CO pollutants. The effect of equivalence ratio, spark ignition timing, engine speed, and the added NG volumetric ratio on CO emissions were tested experimentally. The study outcomes revealed that CO levels depend mainly on the equivalence ratio, as the maximum value of CO concentrations existed at the very rich equivalence ratios and it low at lean side. Retarding spark timing increased the CO concentrations by a significant percentage. The CO levels became higher at high speeds and reduced at medium speeds. Increasing natural gas volumetric ratio in the mixture caused a reduction in CO levels.

The study aimed to determine the radioactivity concentration and radiological assessment in Soil samples around Abu Jubayha, Eastern Nuba Mountains was made by gamma spectrometry technique equipped with NaI (Tl). The result of activity concentration of 226Ra, 232Th and 40K were varied from 23.58 ±7.86 (18.02-29.14), 36.14 ± 5.17 (32.48 -39.79) and 381.88± 127.43 (291.78 - 417.99) Bqkg-1 respectively. Absorbed dose rate and annual effective dose were estimated to evaluate radiological hazards and were varied from 39.47±8.6 (33.38-45.55) nGyh- 1and 38.43±10.56 (40.97-55.9)µSvy-1, respectively .Upon comparing the results with global data, they were found to be within the recommended limits. The result will be serving as a base line for future studies. GIS apocalyptic map was originated and has shown that there were some hot spots with high activity distribution and concentrations of the measured radionuclide and similarly Dose Rate.