Archives-August 2018

A four stroke spark ignition engine is a mechanical engine in which its operation completes by four strokes or movements of piston in the engine cylinder. This engine can also be called gasoline or petrol engine because its basic fuel is gasoline but nowadays, alternative fuels are being considered as the engine operating fuel. The alternative can be mixture of gasoline with other hydrocarbon products like ethanol or singly be another hydrocarbon product that can offer a better performance and lesser consumption when compared with gasoline. Though, the alternative fuels offer lesser consumption but it can also be intensified by considering the engine design specification for better performance which led to the birth of this work. Compression ratio of the engine determines the engine performance, the higher the compression ratio, the greater the efficiency of a spark ignition engine. In ordinary gasoline fuel, higher compression ratio can infer another engine problem like knocking and emission of toxic combustion product but the alternative fuels have been developed to lessen all these effects. The aim of this work was to simulate the influence of compression ratio on an alternative fueled four-stroke spark ignition engine using C# computer program. The simulation model was carried out under assumed varying compression ratio; 4.63, 5.10, 6.00, 6.88, 7.40, 8.28, 9.16, 9.94, 10.45, 10.98 and 11.44, from this, the volume relationship was determined. The mathematical engine simulation model was carried out using thermodynamics-based models. The result of the simulation showed that higher compression gives higher efficiency and the numerical values are in close agreement with experimental values. The percentage error is not more that 2% during combustion duration and efficiency as compared with experimental values. From the numerical results, it was observed that if the compression ratio is high, the crank angle will also be high and this will make the ignition delay period to be diminished. This also goes for the engine performance, power output or the efficiency, the higher the compression ratio the greater the efficiency. Therefore, an alternative fueled engine with compression ratio of 9.16 and above will have a greater efficiency.

The sustainable power source systems (RESs) are an appealing alternative to energize the group as they are condition amicable, free of cost, and all-overrunning. The effectiveness of these vitality systems is low and can be enhanced by coordinating them in parallel. In this paper, hydro (7.5?kW) and PV (10?kW) are taken as RESs and associated with the utility grid. Because of the discontinuous idea of both the hydro and photovoltaic energy sources, utility grid is associated with the system for guaranteeing the ceaseless power stream. The hydro power generation system uses the 3-phase synchronous machine and converters. The AC/DC/AC converter is used as interface to connect the hydro turbine to the utility grid to adjust the generated voltage to the utility grid voltage. The solar generation system is the combination of PV array, boost converter, and solar inverter. The control of both the hydro and solar power plants is provided through the constant current controller. The analysis has been done to verify the existence of the proposed system. Results demonstrate that the proposed system is able to be put into service and can feed the community.

Solvent extraction of lanthanum(III) and vanadium(V) from their aqueous solutions with chloroform solution of 1-phenyl-3-methyl-4-butanoylpyrazol-5-one (the ligand) was studied. The effects of ligand (extractant) concentrations and the pH of the metal aqueous solutions on the solvent extraction were evaluated in terms of their distribution coefficients (D) and the equilibrium constants (Kex) were determined. The values of the slopes of the plots of log D versus log [HBPy(org)] and that of log D versus pH showed that approximately 3 moles of the HBPy ligand reacted with one mole of La3+ while 2 moles of the same ligand reacted with VO2+ during the extraction process. The average logarithms of the equilibrium constant (Kex) values obtained for the metals at the different HBPy concentrations and buffer 4 are -7.40 (La) and -5.14 (V); while those obtained at the different pH and a constant extractant concentration of 0.02 M are La(BPy)3 = -0.49; and VO2(BPy)2 = -1.39; showing that the ligand is an efficient extractant for V(V) and La(III) ions from their aqueous solutions. The study has shown that separation of the La(III) and V(V) ions in their mixture is possible by the adjustment of the extractant concentrations and the pH of the aqueous solution of such mixture.

Honey has been used as a bio monitor to determine environmental quality in the environments which are polluted by heavy metals, radioactivity and pesticides. The study sought to determine the levels of some heavy metals (Cd, Cr, Ni, Zn, Cu, Pb, As, and Mn) in honey and assess their potential health risk to consumers. Samples of honey were harvested from within 5km of the Tamale Metropolis of Ghana. A known weight (5g) of honey samples were digested using an oxi-acidic mixture of HNO3/H2O2 and filtered into a 50ml volumetric flask. The contents of the minerals in the digests were analyzed using atomic absorption spectrometer (AAS). The analysis revealed that the concentrations of lead (79.815 ± 16.796 mg/Kg), nickel (15.785 ± 10.968 mg/Kg), copper (13.855 ± 10.213 mg/Kg) and manganese (8.215 ± 4.452 mg/Kg) in the samples exceeded the FAO/WHO maximum permissible limits. The elevated levels of these metals may be evidence of possible pollution agents (vehicular and industrial emissions, pollution of farm soils and pockets of water) in the study area. The Health Risk assessment (THQ< 1) showed no significant public health risk to consumers. However, we recommend regular monitoring of heavy metals from the natural environment of Tamale to mitigate possible future threats to public health.

The study was carried out to characterize selected conglomerates of the Banket Series of the Tarkwaian at Tarkwa area and related the textures and mineralogy to gold grade and recovery. The conglomerates contain 60-90% quartz pebbles, with the matrix being fine to medium and rarely composed of coarse-grained quartz. The gold ore also comprises of minor fine-grained ore minerals, sericite, and chlorite. The quartz pebbles were glassy, milky and partially recrystallized into sugary varieties. Primary sedimentary textural characteristics of sub-rounded to rounded pebbles of about 0.5 cm to 3.0 cm diameter are common. The quartz pebbles are moderately sorted and well packed. Gold in the ore ranges from 0.78 - 3.86 g/t such that high-grade ores had glassy quartz pebbles whiles medium to low-grade ores had sugary varieties. Gold recovery (38.66 - 95.08%), generally increased with increase in the percentage of the matrix volume. It is also higher in ore containing grey quartz and containing much ore minerals; lowest recoveries have high quartz, low matrix volume, and richer in quartz. Also, associated with lower recovery was higher chlorite content which may require more metallurgical treatment for efficient recovery.

The current interest in numerous studies focuses on deliberating the knowledge about entrepreneurship in graduating students around the world. Even the eminent role of education in the field of entrepreneurship redeem with opportunities to gain knowledge, skills and career aspiration needed for business start-up or new venture but somehow Indian education system failed on implementation. The study reveals a significant impact on graduates’ business start-up. In this study, we examine the knowledge of entrepreneurship amongst the graduating student of India. Moreover, a descriptive survey has been provided using the Chi-Square test. Further, data were analyzed with the help of descriptive statistics and logistic regression. In addition to this, testing of hypothesis is also given. Moreover, also recommend the need of role in entrepreneurship from government and tertiary institutions in shaping the strategy to assist students to start their venture while in school and after graduation through the incubator program. Hence, encouragement to aspiration towards business start-up helps in developing society towards self-employment.

Intradural disc herniation (IDH) is a rarely reported cause of radicular pain. Preoperative imaging can be useful for diagnosis, but differentiation of intra-dural tumors from large disc hernias is difficult and intraoperative findings are required for definitive diagnosis. We present here a case of IDH, which was depicted by high-resolution MRI. It is very representative of the difficulty to make the diagnosis and illustrates the added value of high-resolution MRI when an atypical disc herniation is suspected.

This paper predicted the corrosion rates of three refinery boiler components namely: Baffle wall tubes, vapourizing tube bank and the superheater coils, using a mathematical model developed from the balance equation of the refinery boiler. The results obtained were then compared those already measured by Ultrasonic Thickness Scanning Technique (UTS). The essence is to determine if the prediction equation can be useful in predicting the life expectancy of the various boiler components. The prediction was done for a period of four years. Metal loss recorded for Baffle Wall Tubes was 0.10 mm to 1.10 mm from UTS, while the one from the model was 0.11 mm to 0.98 mm. Metal loss recorded for vapourizing tube bank was 0.06 mm to 1.00 mm from UTS and that from the model was 0.05 mm to 0.98 mm. Metal loss recorded for superheater coil was 0.026 mm to 0.67 mm. The percentage deviation calculated between the model and that from UTS showed a correlation between the rates observed by the different measurement tools. The introduction of the inhibitor model indicated that inhibitor application can greatly reduce the corrosion rates of the refinery boiler’s components. The paper has also shown that the mathematical predictive model can be used to predict the corrosion rates of the internal boiler components as compared to the recorded readings of the Ultrasonic Thickness Scanning Technique.

Adherence to Antiretroviral Therapy (ART) is an important survival factor for people living with HIV/AIDS (PLWHAs). However, patients on ART in Kenya still miss routine check-ups, and get lost to follow up. Research on the factors influencing ART adherence among different populations in Kenya have yielded inconsistent results. The objective of this study was to determine the relationship between patient factors and adherence to ART by adults living with HIV/AIDS in Kisumu County, Kenya. Facility based cross-sectional survey was carried out on patients receiving ART from all the seven Sub-Counties in the County. Systematic random sampling was used to recruit a sample of 386 patients. Data collection tools were pre-tested and piloted to ensure validity and reliability. Chi-square statistic was used to analyze the data at ?=.05. Findings indicated that the relationship between age and ART adherence was statistically significant (?2= 8.064, df= 2, p = 0.034). Similarly, the relationship between alcohol use and ART adherence was statistically significant (?2 = 5.331, df = 1, p = 0.009). Knowledge of ART also had a statistically significant relationship with ART adherence (?2 = 7.799, df = 1, p = 0.0028). However, marital status, level of education, employment status, stigma, and psychosocial support did not exhibit statistically significant relationships with ART adherence. The study concludes that patient age, use of alcohol and knowledge of ART are patient factors related to ART. It is recommended that these factors should be considered in the treatment of PLWHAs to ensure ART adherence.

The aim of this study is to improve Poisson distribution for the approximation of a generalized binomial distribution and to combine the improved Poisson distribution with financial terms for the purpose of evaluating a European call and put option. It was found that the improved Poisson approximates generalized binomial when ? [ ], approximates generalized binomial sufficient enough n, B/A+B when and ? and also that the problem of option for non-dividend paying stock can be approached using an improved Poisson distribution function equipped with some financial terms. The .numerical results obtained is the same as in [4], using the numerical data. Relevant connections of our work with the earlier work is pointed out.