Noise Level Investigation and Control of Household Electric Power Generator

Electric power generator is an essential household facility particularly in developing countries. It exists in various capacities and makes in shops, offices, workshops and factories. The attendant environmental risks of this source of power supply are major challenges to users both at household and industrial level. Efforts through research and development are still on-going to mitigate the prevailing health hazards. This study investigates noise level of typical portable generator (2 kW/220 V) and the sound absorbance capacity of an acoustic enclosure developed from a multilayer panel made of locally sourced galvanized metal sheet (0.90 mm), Polyurethane acoustic foam (7.50 mm), Particle board (35.0 mm) and plywood (10.0 mm). The noise produced by the generator when on load and no load were considered for cases of it being placed inside and outside the enclosure and compared with acceptable OSHA safe thresholds noise level for the school environment where the study was carried out. The result shows a significant reduction of noise produced indicating a shift from very laud threshold (average of 86.23 dB (A)) for no load and no enclosure to moderately low region (average of 69.34 dB (A)) for the case of no load using enclosure. Likewise considering loaded scenario similar trend was recoded with average acoustic capacity of the enclosure of 23.20 dB (A). The effect of the enclosure is positive and the potential benefits of improved noise absorption panels to enhance better performance of the developed enclosure for office and household generators was established. Keywords: Electric Generator, Enclosure Panel, Noise control, Load, Household

Interpretation of Airborne Magnetic Data of Upper Benue Trough, Northeastern Nigeria

Compilation of the airborne magnetic data was conducted by digitizing along the flight line, picking the contour values across each flight line over the upper Benue Trough, Northeastern Basement complex Nigeria. It shows complicated arrangement of long wavelength anomalies, with significant magnetic low. The study of airborne magnetic data revealed some features that are interpreted in terms of deep geologic structures with variation in susceptibility of the basement rocks of thick Cretaceous sediments. The NE-SW trending of the lineament map identifies the same trending of the Benue Trough. Such same trending may be inferred to have the same subsurface structural control. The residual magnetic anomaly map towards the SW region which is the location of Dong and Numan is smoother, which is masked off by the effect of the stronger magnetic basement likely to be a sedimentary basin. The NE-SW revelation shows that this basement region is polygenetic and has experienced magmatism, metamorphism, and structural deformations caused by Pan-Africa Orogeny

LIFE AVERAGE DAILY DOSE OF RADIUM-226 ON SOME WATER SAMPLES COLLECTED AT GIRI AND KUJE AREA OF ABUJA, NORTH-CENTRAL NIGERIA

226Ra concentrations were studied to represent the radiological risk of groundwater of the Giri and Kuje areas of Abuja, North-Central Nigeria. Two borehole water samples were collected from the Giri and Kuje areas of Abuja with a hand-dug well and Abuja Water Board as control. Inductively Coupled Plasma Mass Spectrometry (ICP-MS) was used to measure the concentrations of radionuclide of 226Ra exposed to the dwellers. The activity concentrations of 226R in groundwater supplies for drinking and domestic purposes ranges from 44

ASSESSMENT OF DOSE INTAKE OF TOXIC ELEMENTS IN GROUNDWATER SAMPLES FROM ABUJA, NORTH CENTRAL NIGERIA

This study measured the concentrations of toxic carcinogenic and non-carcinogenic elements present in groundwater using Inductively Coupled-Plasma Mass Spectrometry (ICP-MS). The concentration values obtained were used to calculate the life average daily dose (LADD) exposure of the people whom rely on groundwater for consumption in Abuja, Nigeria. The highest LADD for the carcinogenic toxic element chromium (Cr) was 2.7 x 10-5 μg kg‒1 day‒1, whereas it was 3.3 x 10-4 μg kg‒1 day‒1 for the non-carcinogenic toxic element lead (Pb), identified in water samples collected by the Water Board. These LADD magnitudes of 10-5 and 10-4 for both carcinogenic and noncarcinogenic toxic elements in groundwater are far below the International Reference Dose according to the United States Environmental Protection Agency (USEPA) in 2008, which has a value of 10-1. The low magnitudes found in water samples may not pose significant health risks to the local population. The relevant authorities should, therefore, continue to monitor the impact of human activities on metal pollution in this area and take effective measures to control contamination of the public water suppl

Computational analysis of conductive heat transfer in a rectangular slab of stable boundary using Monte Carlo method

Heat transfer is of immense importance in many engineering studies. Monte Carlo technique are broadly utilized in the operation research fields and atomic physics in which difficult problems above the existing tools of theoretical mathematics were resolved. The target of this study is to confirm the short duration in which heat transfer occurs in a quadrilateral slab where the temperature is provided throughout the borderline. An effort was made towards providing appropriate condition for the explanation of the heat transfer in a substance. The Shrinking Periphery Monte Carlo technique was utilized to obtain heat transfer in a helical pattern, upward and downward movement, which was compared with the standard Monte Carlo technique. The result of the study showed that the dimension of the quadrilateral slab determines the duration to calculate temperature dissemination in the system. The study revealed that the helical pattern is the shortest route in computing run time for temperature dispersal in a slab. The helical pattern is paramount in determining temperature distribution in a quadrilateral slab of stable state. The application of this technique to examine the conduction of heat in quadrilateral slabs produced good outcomes

Dust pollution and its potential health risk exposure to inhabitants of Covenant University and canaanland, Ogun state, Nigeria

Understanding the background concentration of heavy metals in dust samples is so much important for identifying and managing pollution. Thus, these concentrations in dust can be distributed indoors and outdoors in order of magnitudes. This study demonstrates the risk analysis of dust samples collected from selected buildings in both Covenant University and Canaanland using Atomic Absorption Spectrometer (AAS). The obtained concentrations were used to determine the Geoaccumulation, Contaminant Factor and the Pollution Loading Index (PLI). The highest geo-accumulation index and pollution loading index of 3.108 and 0.5836 due to chromium (Cr) contents in the dust samples were noted in Lecture Theatre 2 (LT2). The higher values found in LT2 may be due to the wide open of both doors and windows. Both the Geo-accumulation Index and Pollution Load Index were found to be lower than the permissible level suggested by World Health Organization (WHO) and United State Environmental Protection Agency (USEPA). Significantly, these observations from this study will provide the basis for the background concentrations and potential risks of some important heavy metals of environmental concer

Determination of a spark ignition engine's performance parameters using response surface methodology

combustion engines are concerned, emission is the important parameters for which the other design and operating parameters have to be optimized. This paper studies the use of RSM (Response Surface Methodology) to optimize the performance parameters of a 4-stroke spark ignition engine. In this work, a description of the facilities developed for conducting experimental work on the test engine experiment was conducted. Theoretical evaluation, experimental evaluation, prediction of performance parameters using RSM and statistical evaluation of SI engine were performed. The study also explained how to build an analytical model for the complicated problem. The development of the incombustible gases concentration (part per million-ppm) as a function of engine speed (rpm), loading condition (%) and operating time (seconds) was done via 23 factorial designs of the experiment (DoE )and RSM. The results obtained from HC, CO and NOx emission models showed that the engine speed, loading condition and time were found to have significant influence on the emission. The HC, CO and NOx emission models have also proved positive response from the regression analysis of actual and predicted responses. In the error estimation with 95% confidence interval the equations are within the ranges. Thus, the response surface methodology provides useful informatio

Potential Health Risks of Heavy Metal Contents in Bottled Water from Lagos State and Its Environs, Nigeria

The concentrations of lead (Pb), Cadmium (Cd), Chromium (Cr), Nickel (Ni), B and Fe in twenty (20) different brands of bottled water samples were investigated to ascertain the risk exposure to consumers using Atomic Absorption Spectrometry (AAS). The concentrations of the heavy metals analyzed varied from bottled water to bottled water samples. The BE bottled water sample was found to contain the least concentration of Pb with a value of 0.0232 mg/l. The risk of chronic daily intake (CDI) was determined based on the United State Environmental Protection Agency (USEPA) model for health risk. It was observed that Fe, Mg and Ca reported in all the bottled water samples. The estimated Chronic Daily Intake (CDI) of different metals from the water samples is found to be in order of magnitude of Pb> Fe>Cd>Ni. The highest CDI found in VA, SO, SO, LAT water samples are higher than the International Reference Dose Level according to WHO and USEPA respectively. This study suggest that some bottled water factories should be sited in zones that are safer from these heavy metals if Reverse Osmosis machine for proper removal of these trace elements from the raw water is not in use for water treatment