13 research outputs found
Hazards Assessment Analyses of Fossil-fuel Generators: Holistic-study of Human Experiences and Perceptions in South-Southern Nigeria
Get PDFUsers of fossil-fuel generators for electricity-supply to households/buildings/premises/apartments in Port-Harcourt, Uyo & Calabar metropolitan-cities [and environs] of Nigeria, with their Neighbours were repeatedly engaged for three (3) consecutive years, to determine their subjective-perceptions and experiences of the associated environmental, health, psycho-social, financial, security and safety hazards/issues etc. Field surveys/investigations were conducted on the study-area, which was segmented into three-hundred (300) settlement-clusters; then, tailor-suited questionnaires were administered to generator-users and their neighbours [as "˜respondents']. After analyzing the data, research-findings revealed that: There is an overwhelming dependence on, and a prevalent/predominant use [80.1% of all 68,400 households/buildings/premises/apartments surveyed in 3 years] of fossil-fuel generators in these cities and environs. Some generator-users are fully-aware and "˜strongly-agree' that, there are related: Environmental-hazards [air-pollution (50.9%) and noise-pollution (48.8%) etc.]; Health-hazards [sleep-disturbance (84.6%), hearing-loss (67.1%), ophthalmic-problems (45.0%) & difficulty in mental-concentration (88.8%) etc.]; Psycho-social issues [quarrels/verbal confrontations (89.4.0%), reports to local-authority(ies)/mediation (6.4%), revenge-attempts (2.6%), forced-relocations (1.3%), arrests (0.2%) & litigation (0.1%) etc.]; Financial-implications [purchase-costs ranging from US60,606.06 etc.]; Security concerns/challenges [the 5,500 reported cases of gunshot-violence i.e. 41.8% of all 13,158 generator-related crimes committed etc.]; and Safety-hazards [fire-incidences, fuel-ingestions and deaths accounting for 5.6%, 60.5% and 2.2% resp. of all 8,928 reported-cases of generator-use related accidents]
Post-Project Environmental Impact Evaluation of Ota Industrial Housing Estate on the Localized Environment and Environs in Ogun State, Nigeria
No full textIn this research paper, twelve (12) consecutive weekly field-studies were carried-out within a study-period of three (3) months to determine the current baseline environmental data of the study-area—'Ota Industrial Housing Estate and Environs' by conducting a Post-Project Environmental Impact Evaluation (EIE) of the Estate's industrial wing on its residential wing—which was divided into three Catchments (Catchment 1, Catchment 2 and Catchment 3) in addition to Catchment 4 (i.e. its Environs) which is a proximal neighbouring community to the study-area called ‘Obasanjo locality’. Consequently, standard experimental procedures were engaged to determine the baseline data values of the selected biophysiochemical environmental parameters of the study area, which were then compared with the values obtained at the Control-environment [i.e. ‘Atan locality’ which is a distant community located about 15km from the study-area] and/or with the benchmark values/limits recommended by global and national standardizing bodies (organizations) [such as the' ' WHO , ' ' ISO , ' ' OSHA , ' ' ASTM , ' ' APHA , ' ' DPR ,' ' SON and ' ' FMEnv] for human safety. Based on the experimental results obtained, some of the inferences made are summarily stated below. Majority of the measured microclimatic, acoustic and outdoor air quality parameters are higher than the standard recommended limits and the control environment’s values. The Soil Nutrients' and Heavy metals' concentrations are randomly distributed. The predominant land-use type is 'Residential' while the least is 'Educational'. The predominantly occurring vegetation is 'Elephant grass (Botanical name: Permisetum Purpuretum)'. Apart from pH, Electrical Conductivity, Temperature, Dissolved Oxygen( ) DO and Biochemical Oxygen Demand( ) BOD , all the other Groundwater quality assessment parameters are higher than the standards’ recommended limits. Thus, the industrial wing of ‘Ogun State Industrial Housing Estate’ environmentally impacts its residential wing and environs negatively
Experimental Evaluation of Radiological Hazards in Ceramic Tiles Used in the Jos-South, Area of Plateau State, Nigeria
Get PDFRadiological hazards resulting from 5 different brands of ceramic tiles commonly used in homes and offices in Jos-south area ofplateau state were assessed in this study by carrying out radioactivity measurement of natural radionuclides (40K, 226Ra and 232Th) in them using a NaI(Tl) gamma ray spectrometer. The ceramic tiles had mean activity concentrations of 44.5, 59.6 and 417.4 Bq kg-1 for 226Ra, 232Th and 40K respectively. The average radium equivalent is within the recommended limit of 370 Bq kg-1 for building materials. The radiological hazard indices such as the gamma absorbed dose rate, annual effective dose, external radiation index (Hex), internal radiation hazard index (Hin), Alpha index (Iα), Gamma index (Iγ), excess lifetime cancer risk, and annual gonadal dose equivalent were evaluated. The results obtained show that the radiological parameters do not exceed the recommended safety limits and hence pose no significant radiological hazard when used as building material
AN INVESTIGATION OF THE INFLUENCE OF FEMTOCELLS NETWORK ON A SMALL SIZE INDOOR ENVIRONMENT USING ITU-R AND WINNER II PATH LOSS MODELS
Get PDFThe rapid integrations of wireless controls in mechatronics, the broadening applications of
wireless radio communications in aviation, and the exponential increase in the growth of
mobile phone users in the last decade have made it necessary to expand the capacity of
GSM users and ultimately increase the system performance. It has also become imperative
for service providers to ensure adequate coverage is provided for all mobile users in areas
with poor or no service. Even though many solutions such as distributed antenna system,
relays, macrocells, and picocells were developed but they could not proffer the needed
solution to indoor users. In this perspective, researchers were of the opinion that femtocells
have a gifted technology to enhance indoor coverage because of properties such as short
power, short coverage area, reduced distance between device and user and being a plug
and play device. It was however discovered that research findings on large deployment of
femtocells does not corroborate when a handful is deployed. This study therefore examines
the influence of femtocells network on a small size indoor environment using ITU-R and
WINNER II path loss models. To accomplish this, femtocells were modeled in six
apartments of a building and parameters such as path loss, received power and signal to
interference plus noise ratio were determined to ascertain the performance of a particular
femtocell under the influence of co-tier interference. Results show that the ITU-R model
was found to experience lower path losses which produced higher received powers than
WINNER II (-57.0445dBm on the average)
Performance Evaluation of Developed Mathematical Models of Hot Air Balloon for Drone Application
Get PDFdesigning a hot air balloon necessitates an accurate model of its dynamics. In many of these applications, control of the balloons
is important and requires proper mathematical modelling of the mechanical and thermal dynamics of the balloon. Although
complex thermodynamic models have been developed, this research would address the use of simple heat transfer and
performance relationship to develop a comprehensive hot-air balloon model for drone applications. The mathematical model
comprises of a heat transfer model and a performance model, considering that the motion of the system is governed by heat
transfer between the system and the surroundings. For the heat transfer, two models were developed (model 1 and model 2).
Model 2 proved to be more accurate than Model 1 upon simulation. The simulation runs of the first and second model were
compared using the simulation data inspector on Simulink to determine the difference between the signals graphically. The result
shows that the second model (orange) is more responsive to heat loss than the first model (green)
Experimental Determination of Drinking Water Quality in Abeokuta Metropolis, South-western Nigeria
Get PDFIn this study, fifty (50) randomly selected drinking water sources in Abeokuta metropolitan city in Ogun state, south-western Nigeria; were experimentally studied to determine their suitability to be designated as “Safe Drinking Water Sources”. Thus, water samples collected from each of these fifty(50) drinking water sources [comprising of ten (10) Taps, fifteen(15) Hand-dug wells and twenty(25) Bore-holes] were repeatedly subjected to one(1) microbiological and twenty-five(25) physico-chemical analytical tests, in accordance with the standard test procedures specified by ASTM, APHA and USEPA, under laboratory conditions. This was done, in order to determine whether/not the fifty (50) tested drinking water samples conformed to the global (WHO) and national (NSDWQ, SON) standards’ requirements for potable (safe drinking) water. Consequent upon testing, it was observed that, 100% i.e. all fifty(50) drinking water samples showed conformity to the standards’ requirements with respect to Alkalinity, Salinity, Total hardness, Turbidity, Electrical-conductivity, Temperature, Total Dissolved Solids, BOD, Sodium, Potassium, Calcium, Magnesium, Chloride, Sulphate, Nitrate, Zinc, Chromium and Manganese contents. With exception to the Iron content, in which all the water-samples exceeded the standard’s limits, [although, no adverse health conditions are associated with this]; 78% (39 samples), 12% (6 samples), 84% (42 samples) and 10% (5 samples) of the water samples failed to conform to the standard’s requirements in terms of pH, Lead, Cadmium and Zero-count of Total coliforms; with values ranging from 4.336.77 , 0.000 0.074mg / L , 0.001 0.081mg / L and 1.04.0 counts /100mL respectively.The respective health implications of these cases of non-conformity include disequilibrium in the body’s alkalinity-acidity balance, cancer, nervous system dysfunction, kidney-related problems and low-risk total-coliforms contamination
Reverse Engineering Approach for the Design of Gear-box for a Hand-guided Vibratory Roller Soil-Compactor
No full textSoil compaction is one of the most critical components in the construction of roads, airfields, embankments and foundations. For a developing country like Nigeria, the equipment needed to compact soil for the above-mentioned purposes especially in the rural areas needs to be readily available. However, this is usually not the case as most of the available equipment like Roller compactors are imported. A cheaper and faster way to make them available is by reproducing the existing ones through ‘Reverse Engineering’. Reverse Engineering (RE) can be defined as the process of discovering the technological principles of a device, object or system through analysis of its structure, function and operation usually for the purpose of reproducing it or for a more competitive procurement. In this project, the Reverse Engineering design (mechanical) of a parallel shaft gearbox for use in a hand roller compactor was carried-out. Its entire functionality was outlined and the engine capacity to be coupled to the gear box in order to provide the required energy for an acceptable soil compaction was determined. The energy required according to Standard Compaction Test AS 1289 – E1.1 ranges from 595 KJ/m3 to 2072 KJ/m3 according to the Modified Compaction Test AS 1289 – E2.1. Therefore, the energy required for various levels of compaction, ranges between these two values. Four different soil types were considered and the energy required for different ‘Compacted lift thicknesses’ using the parameters of the hand roller compactor were found to fall within the above values (595 – 2072 KJ/m3), thus, justifying the viability of this design procedure
City-wide Quality Assessment of Sandcrete Masonry Blocks Produced in Lagos, Ibadan and Abeokuta Metropolitan-cities in South-western Nigeria
Get PDFIn this research work, a total of nine thousand (9,000) numbers of Sandcrete masonry blocks and another total of nine thousand (9,000) numbers of Sandcrete masonry blocks were collected as Test-samples from three hundred (300) Sandcrete block-making factories, which are randomly sited in thirty (30) rapidly developing towns/localities located within three (3) highly-populated and state-capital metropolitan-cities—i.e. ‘Lagos’, ‘Ibadan’ and ‘Abeokuta’ in South-Western Nigeria. Thus, from the cumulative total number of eighteen thousand (18,000) Sandcrete block test-samples, each of the thirty (30) numbers of ‘block test-samples’ and each of the thirty (30) numbers of ‘block test-samples’ which were collected from each of the ten (10) Block-making factories per town/locality was subjected to two (2) critical quality-evaluation tests—i.e. Compressive-strength test [using a compression-testing machine] and Water absorption coefficient test [in accordance with standard established procedures and then, the mean values were computed and adopted as the representative/characteristic data for each Block-making factory. Consequently, the obtained results/data were then comparatively analyzed using the Standards Organization of Nigeria ‘SON’standard specified (recommended) values to empirically evaluate the Block-making/production quality of each of town/locality per city and of each city. Amongst other things, the comparative analysis of the obtained results/data showed that: while all of the tested Sandcrete masonry blocks produced in Lagos city and Ibadan city are classified as substandard—having failed to meet (fulfill) the standard requirements; just of the Sandcrete masonry blocks, and as much as of the Sandcrete masonry blocks produced in Abeokuta city are classified as standard—having successfully met (satisfied) the Standard requirements—thus, making them the most ideal for construction purposes
Performance enhancement using appropriate mass charge of R600a in a developed domestic refrigerator
Get PDFThis paper presents performance analysis of a domestic refrigeration system using
R600a as refrigerant. Investigation was conducted experimentally to select an appropriate
refrigerant mass charge for the system and to compute the cooling system performance
characteristics under ambient temperature of 29 oC. The choice of the hydrocarbon refrigerant
(R600a) became so imperative due to notable influence of chlorofluorocarbons (CFCs),
hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs) on global warming and
ozone depletion. UNFCCC and Montreal Protocol regulation have banned the use of
halogenated refrigerants in cooling and heating systems. The paper reveals that the power
consumed by the system using mass charge of 15 g refrigerant was reduced by 9.3 and 10.9%
compared with the 10 and 25 g refrigerant mass charges respectively. In addition, the results
show that the coefficient of performance (COP) of the refrigeration system while working with
15 g is 24.7 and 20.2% higher than when the system worked with 10 and 25 g refrigerants
mass charge respectively. More so, the system attained an evaporator air temperature of -12 oC
in 2 hours, which makes 15 g charge refrigerant appropriate for the running of the developed
system that has a volume capacity of 68 liters
Noise-level Characterization of Portable Electric-power Generators in North-Central Nigeria: A Brand-by-Brand Comparative-study
No full textThis two-year study presents the average experimental results/data obtained from twelve (12) scientific investigations sequentially conducted on the noise-levels of electric-power generators used in seven (7) major cities—[Abuja, Makurdi, Lokoja, Ilorin, Lafia, Minna and Jos] of North-Central Nigeria. Fifty (50) popular models of electric-power generators produced by ten (10) leading generator-brands which were imported to, and used within the study-area were first identified. Then, using the CR C 811 Noise meter, the Perceived Noise Level (Lpn), Sound Pressure Level (Lp) and Sound Power Level (SWL) of each of the fifty electricpower generator-models were obtained twelve times through field measurements and computation; in addition to recording the ‘Usage time-periods’ and ‘Rated electric-powers’ during each investigation. After which, a collation and graphical illustration of the respective average values obtained, showed that: majority (80%), two-thirds (66%) and below half (42%) of the total number of tested electric-power generator-models used (operated) in the study area did not conform to three (3) international noise emission requirements [i.e.' 85 ' L dB P , ' 87 ' L dB P and ' 90 ' L dB P ], since most of the generators exceeded the standard 8-hour Recommended Noise Level (RNL) specified by ‘NIOSH’, ‘IOSH’ and ‘ OSHA’ for human safety respectively. Without doubts, this poses a serious health risk to the millions of people presently living in these North-Central Nigerian cities
