Risk Management Assessment of Production in Granite Stone: A Case Study of Quarries in Ondo, Ogun and Oyo States, Nigeria
Author(s): M.M. Melodi, A.A. Adeyemo, V.I. Oluwafemi
Abstract: This study was on the risk management analysis of labour and equipment for effective production output in quarries, in Ondo, Oyo and Ogun States of Nigeria with aim of identifying the work hazards encountered by quarry workers, assessing the level of risk faced by quarry worker’s, examining the likelihood of occurrence of hazards at quarry workplace and precautionary measures put in place. Sixty quarry workers were randomly selected across both skilled and unskilled division and were administered with a structured questionnaire to know the various hazards and hazard management during their operations in quarry. Data collected were analysed using descriptive statistics, frequency tables and charts. Potential Hazards faced by respondents according to the analysis are electric shocks (69.23%), noise pollution (86.15%), dusts impact (86.15%), fly rocks during blasting (52.31%), excessive workload (73.85%), long hours of work (80.00%), slips and trips (93.85%) and wet floors/road (50.77%). Victims include the community people (64.62%), operators (69.23%), visitors (56.92%) and new workers (63.08%). Risk control measure mostly used was first aid facilities and this was adequate. Workers are also likely to experience fly rocks (26.2%), long hours of work (49.2%), wet floors/road (33.8%), hydrocarbon fuel spillage (52.3%), runoff from sites (33.8%) and soil erosion to farmlands (32.3%), dust impact on visuals (55.4%). Quarry workers (64.6%) attest they do not attend safety seminars because they are not given by the management. A proportion of 24.6% of the quarry workers has not been involved as causalities of any hazard despite the regular (always) breakdown of workers (40.0%) at the workplace. The results of the water analysis revealed the level of heavy metals like Lead (Pb), Cadmium (Cd), Magnesium (Mg) and Chromium (Cr) are higher than the permissible limit recommended by WHO; hence the water sources pose a great threat to the health of the people and workers.
Influence of Physical Properties of Cassava Tubers on the Performance of an Automated Cassava Peeler
Author(s): Olufemi Adeyemi ADETOLA
Abstract: Cassava peelers have not been fully developed due to irregularity in shape, size and weight of cassava tubers. The key objective of the study was to determine the impact of physical properties of cassava tubers on the performance of a cassava peeler. Eight tillage treatments were used, namely: ploughing + harrowing; ploughing + harrowing + ridging; manual ridging; flat manual clearing; ploughing + harrowing + manual digging to a depth of 30 cm + 10 cm saw-dust placed at the base; ploughing + harrowing + ridging +10 cm saw-dust placed at the base; manual ridging + 10 cm saw-dust placed at the base and manual digging to a depth of 30 cm + 10 cm saw-dust placed at the base. One improved cassava variety, one nutrient dosage and two soil conditions were used. Statistical Package for Social Science window 21 versions was used to analyze the data. Peeling efficiency, percentage broken tubers, percentage flesh loss, machine throughput capacity, mass of unpeeled patches and material recovery ranged from 28.05-92.88 %, 15.00-46.69 %, 8.78-42.88 %, 0.48-0.58 tons/h, 0.46-1.82 % and 69.56-92.55 % respectively. The physical properties of cassava tubers had influence on the performance evaluation parameters of an automated cassava peeler.
The Development of a Web-based Application of Examination Seating Arrangement for Student
Author(s): Sunday ADETONA, Edison HASSAN, Raifu SALAWU, Samuel OMOLOLA
On the Performance Analysis of Yagi-Uda at Wide Range Operational Frequencies
Author(s): Akeem Abimbola RAJI
Abstract: This paper evaluated the performance of Yagi-Uda antenna at High Frequency (HF), Very High Frequency (VHF) and Ultra High Frequency (UHF) communications. By employing popular method of moments algorithm for transforming electric field integral equation into a matrix equation, the current amplitude on the antenna emerged after matrix inversion of impedance matrix and multiplication by the voltage. The far zone field expression was developed by taking an integral of known current amplitude and green’s function. Using radiation far zone pattern as the performance metric, it was found that, the antenna was characterized by significant main lobe radiation along the axis of the antenna with small minor lobe radiation. This characteristic remains unchanged over all frequencies utilized as candidates for investigation. It was revealed through the study that varying operational frequency has negligible effect on the radiation characteristics exhibited by Yagi-Uda antenna and this lends credence to its usage for a number of applications over a wide frequency range.
Synthetic Generation of Daily Rainfall Amounts of Gombe Town
Author(s): A. O. Ibeje
Abstract: Usually the length of a rainfall record is insufficient to contain extreme values and critical sequences required for the design of water resources system components. Stochastic rainfall model which has to do with the occurrence of wet day and depth of rainfall is developed for Gombe town located in semi-arid region of Nigeria, which depends on rainfall as the main source of irrigated agriculture but has limited rainfall record for the design of irrigation system. The first-order Markov-chain model was used to generate the sequence of rainfall occurrence using the method of transitional probability matrices, while daily rainfall amount was generated using a gamma distribution. The model parameters were estimated from 1991-2001 historical rainfall records. When the observed rainfall and the synthetically generated ones were compared, the statistical characteristics were satisfactorily preserved with a correlation coefficient of 0.99. Evidently results obtained have shown that the model could be used to generate rainfall data satisfactorily for the design of irrigation facilities in Gombe, Nigeria.
Impact of Installation of Static Var Compensator on Available Transfer Capability on Electric Power Grid
Author(s): Sunday ADETONA, Olatunde OGUNDEJI, Ayangbenjo ADEYEYE
Abstract: This contribution analyses the impact of installation of Static Var Compensator (SVC) on Available Transfer Capability (ATC) on Electric Power Grid (EPG). The state Bifurcation Criteria (sBC) was used to evaluate the ATC of the EPG, and also to establish optimal location for the injection of the SVC on EPG; whereas, N-1 contingency analysis (N-1CA) was utilized in identifying the most severe transmission line in the EPG. The ATCs of the grid were evaluated under normal situation and contingency with and without the injection of SVC at the identified optimal location. The Western System Coordinating Council (WSCC) 9-bus network was used as the test bed; which was modelled in PSAT in the MATLAB environment. During the simulation exercises, the ATC obtained without the injection of the SVC in the grid was 3.4380 pu to 3.6319 pu gotten with the same condition but with the injection of SVC at the identified optimal location of the same grid. When the EPG was subjected to a critical constraint, the ATC of the same grid during contingency without SVC at the optimal location was found to be 0.5372 pu; whereas with SVC injected, it was 0.6692 ??. The result reveals that ATC of the grid is significantly improved by 5.64% when the grid is under normal conditions and when SVC is injected. The result obtained when the EPG was subjected to severe contingency also shows that the ATC of the EPG is significantly improved by 24.57%.
Application of the Shrinking Core Models to Hydrochloric Acid Dissolution of Alumina from Clay
Author(s): Henry Oghenero ORUGBA, Okechukwu Dominic ONUKWULI, Babayemi AKINPELU, Umeuzuegbu JONAH
Abstract: The steady depletion of bauxite which is the major source of alumina from which aluminium is produced has prompted the need to seek for means of obtaining alumina from other materials like clays that are relatively high in alumina content. Acid leaching has been found to be a viable means of obtaining the ore from clays. In order to design alumina dissolution process from clays, the influence of process parameters as well as values of the relevant thermodynamic parameters on the yield of alumina must be determined. In this research, the local clay was characterized to ascertain its viability for alumina production. The influence of particle size of clay, stirring speed, leaching temperature, acid-to-clay weight ratio and acid concentration on the yield of alumina from the local clay were studied. In order to develop a kinetic model for the dissolution process, the different forms of the shrinking core model were tested with the experimental data. The characterization result revealed that the clay having 33.9% of alumina is a viable source of producing alumina. With the exception of particle size of clay, increasing all the parameters tested showed increase in the percentage of alumina leached from the clay. The results of the model testing showed that the liquid film diffusion controlled model gave the best fits for the experimental data and based on the Arrhenius equation, the activation energy for the dissolution process was calculated to be 35.32 kJ/mol.
Development of a Low Cost Smart PIG and Wireless Sensor for the Detection of Pipeline Defects and Anomalies
Author(s): Oluwafemi OLUGBOJI, Mathew ABOLARIN, O. Adedipe, Gbenga ATOLAGBE, Adinoyi SADIQ, O. Ajayi
Abstract: Inspecting the inside or outside circumstances of a buried pipeline is very difficult, as visual inspection is overwhelming and costly; also the procurement cost of most conventional Pipeline Inspection Gauges (PIGs) are usually overbearing; and they usually come in huge sizes, making it too heavy to install. This study aimed at developing a low-cost smart PIG for defects (leakage) detection in pipelines. The smart PIG was developed using locally sourced materials and off-the-shelf sensors and electronics to provide a low-cost alternative to traditional Intelligent PIGs. The major components used in the design includes: SparkFun Pressure Sensor Breakout: MS5803-14BA, Motion Sensor (SparkFun 9DoF IMU Breakout: LSM9DSI), the wireless communicator (ESP-01S ESP8266 WiFi module) and Arduino MicrocontrollerA no-load test was carried out on the pig by conveying inside a 160mm diameter pipeline of length 6.7m using a 0.125hp D.C motor and a gearbox attachment to pull from end to end. Data were retrieved using a WiFi module and PuTTY software. Pressure irregularities (spikes) were observed at the points of obstruction, based on the pressure values plotted. The higher pressure pulses (spikes) which were observed at the points of defects created along the pipeline was an indication that the Smart PIG was capable of detecting the created defects. This was an indication that the low-cost smart pig was capable of detecting leakages and can serve as a suitable alternative for the traditional In-line Inspection tools.
Design and Construction of a Two Channel Microcontroller Based Remote Control for switching Electrical Appliances
Author(s): Mobolaji Aduramo SODUNKE, Adeyemi Idris, OLATEJU, Yusuf Babatunde LAWAL, Joseph Ogheneruemu ODIETE, Taiwo Titus ABATAN, Waliu Mufutau OLAYEMI
Abstract: This paper presents the design and development of a system that can switch off andon Electrically poweredappliances or wall sockets at user’s will remotely. This research is aimed at increasing the accessibility as well as response rate to prevent appliances from damage due transient, intermittent and fluctuations in power supply. This system uses a wireless telemetry technique through an infra red (IR) transmitter and receiver to control the switching state home and laboratory/industrial electrical or electronic devices through the electrical sockets.The entire circuit is built around ATMEGA-328P microcontroller which was programmed to interpret a digital signal sent from the IR transmitter (remote control) to the IR receiver. As the microcontroller receives a real time signal from the Ir transmitter through the Ir receiver module, command is being sent to the relay switching unit which either activates or deactivates either a single channel or both channels as embedded in the software code. The normally open ( N/O) and normally closed (N/C) of the relay are connected to the live terminals of AC sockets for automation. The Liquid Crystal Display (LCD) displays the status of the sockets in any of the two channels (points) as instructed by the microcontroller. The system is cost effective, durable and versatile as it can be applied to any devices connected to electrical socket outlet.
Investigating the Rate of Uptake of TPH, TOC, Organic Matter and Some Heavy Metals By Melon Grass in a Crude Oil Polluted Soil in the Tropical Region
Author(s): M.C. Uwazie, O.D. Onukwuli, A.K. Babayemi, J.C. Umezuegbu
Abstract: This research was aimed at finding the rate at which melon grass take up TPH (total petroleum hydrocarbons), TOC (total organic carbon) and heavy metals like lead, zinc, nickel, potassium, calcium, from a petroleum contaminated soil. Four wooden boxes were made and 7.5kg of soil was added in each of the boxes. These two boxes were also polluted with 150g of crude oil, one out of these two boxes was amended with 150g of cow dung. The other two boxes were also polluted with 75g of crude oil, also one box out of these two was amended with 150g of cow dung. A control box which has no crude oil contamination was also grown to aid comparisons. At the end of the three months growth period, melon grass was able to remediate TPH from an initial 6.784µg/g (for 75g pollution) to 6.356µg/g, and from an initial 9.109µg/g (for 150g pollution) to7.713µg/g. Lead was reduced from 0.699mg/kg to 0.002mg/kg, zinc was reduced from 0.851mg/kg to 0.506mg/kg. It was discovered that a close corresponding value of what was remediated from the soil was found in plant. Nickel however did not show any significant change in value. A predictive mathematical model was developed to predict how long it will take to remediate TPH and the heavy metals and bring the soil back to its original state.
Experimental Investigation of Greenzyme Adsorption on Sand Surface
Author(s): Tinuola H. UDOH, Victor EKANEM
Abstract: Greenzyme applications in oil reservoir is an emerging enhanced oil recovery process but its adsorption on the rock surface may result in the loss and reduction of its concentration during flooding hence, rendering it less efficient in practical application. This paper presents experimental study on greenzyme adsorption on sand surfaces of different grain sizes at varied temperatures. The concentration depletion method that accounts for the difference in enzyme concentrations in solutions before and after contacting the sand surface was used to determine the enzyme adsorption on relevant surface. The results show that adsorption of greenzyme on sand surface increases with increase in its concentrations and when small sand particles are used. Increase in system temperatures however resulted in reduction of its adsorption on the sand surface irrespective of the sand size and the concentration. Finally, the experimental data were fitted with Langmuir and Freundlich adsorption models and the results show that adsorption of greenzyme on the sand surface is better modelled with Langmuir isotherm.
Assessment of Three Selected Locations in Nigeria as Offshore Windfarms Using Multi-criteria Decision Procedure
Author(s): Ezekiel Asuku MAYAKI, Oyewole ADEDIPE, Uzoma Gregory OKORO, Rabiu Onoruoiza MAMMAN, Sunday Albert LAWAL
Abstract: The continuous rise in carbon footprints arising from industrial and domestic activities has placed urgent need on renewable energy sources globally. Wind as a renewable energy source is gaining global prominence because it can be harnessed in small and commercial quantities. Several studies have been carried out on the subject of wind energy. However, this paper is focused on multi-criteria evaluation of three Nigerian coastal locations (Lagos, Port-Harcourt and Warri) for consideration for installation of offshore wind farm to improve energy availability in the country. In this paper, attributes for offshore wind farm location were collected for three locations in Nigeria; Victoria Island (VI) in Lagos, Abbonema area of River State and Koko area of Warri. Ten-year wind speed data for the three locations were also collected from the archive of Nigeria Metrological Agency (NIMET) while other required factors were collected with the use of a well-structured Questionnaire and the respondents were senior staff of the Nigerian Airspace Management Agency (NAMA) and NIMET. Collected data were analyzed using Multi-Criteria analysis tool (TOPSIS). Average of a ten-year wind speed data for Lagos (VI), Koko (Warri) and Abonemma (Rivers) were 6.251m/s, 7.294m/s and 7.347m/s respectively. Analytical Hierarchy Process (AHP) gave a Consistency Index of 0.123029264 and Consistency Ratio of 0.084266619. The consistency ratios from the AHP were used to calculate the required Criteria Weight (Cw) for the TOPSIS analysis. From the cumulative value of the analysed factors, Victoria Island (Lagos) has the highest figure of 233.6677 with a consideration rate of 38% and this places it above Koko (Warri) and Abonnema (Rivers) with a value of 187.7704 (30%) and 195.4377844 (32%). Based on the analysis carried out, Victoria Island Lagos appears to be the best option for offshore wind farm consideration.
Proximate and Ultimate Analysis of Municipal Solid Waste for Energy Generation
Author(s): Oluwasina L. ROMINIYI and Bernard A. ADARAMOLA
Abstract: Municipal Solid Waste (MSW) has become a burden globally. Solid wastes, if not properly managed is an eyesore, contaminate the environment and lead to outbreak of diseases. This work focuses on the determination of MSW composition in Ado-Ekiti metropolis. A laboratory procedure known as proximate and ultimate analyses was used to determine the composition. The samples of the MSW used in this research were sorted, sundried, pulverized and sieved. The average waste generated per day in Ado-Ekiti is 300 tonnes as shown in table 5. With 2015 as the base year, the per capita waste generation was computed using equation (1) as 0.67 kg/day within the metropolis. The energy content of the combustible MSW was evaluated using Cal 2k-Eco Calorimeter (electronic bomb calorimeter). The energy content generated from MSW ranges from 47,272.87 MJ/day to 1,361,407.74 MJ/day in table 6, while the total energy content is 4,449,426.14 MJ/day. The mean specific energy content is 17.57 MJ/kg. Polythene products waste can be used to generate 15.76 MW of electricity while the combustible components of the MSW can be used to produce steam to generate 51.5 MW of electricity in Ado-Ekiti.
An Innovative Production of a Sustainable Termite Resistance Sandcrete Block Using Jimson Weeds (Datura stramonium)
Author(s): Stephen Adeyemi ALABI, Olawale Bidemi AJAYI
Abstract: The problem of termite attacks is very common in sub-Saharan Africa region and this makes components of building structures such as timber very vulnerable to attacks. In an attempt to effectively protect these construction materials from termite attack, it is more effective to deal with the pathway through which termites gain access into the building structures. The toxicity of available synthetic chemicals to human health and the environment calls for the use of alternative natural plants as insecticides and developed them as termite-repellent materials. One of such plants identified is Jimson weed (Datura stramonium, DS). Metal analysis was carried out on both its seeds and leaves, the seed were identified to be more acidic and repelled termites. The aqueous seed extract with 0.2 mg/l concentration was added to the potable water used to prepare sandcrete block at varying percentage. The effect of termite on the piece of wood in sandcrete blocks placed on earthen and concrete surfaces were studied. It was observed that as the percentage of Jimson extract increases, the termite activity reduces. The results showed that DS extract is found to be acidic, making it very toxic to termite. The compressive strength and water absorption of sandcrete hollow block made from DS extract increases with increasing curing time. The results showed that the Jimson weeds can effectively reduce the termite activities on the building components. It can be recommended that the extract be effectively applied after laying the foundation before laying the block walls so as to ensure long time sustainability of the whole building.
Synthesis of Zeolite A from Aloji Kaolin to Investigate Its Performance in Hard Water Softening
Author(s): Elizabeth O. OKPONG, Patience O. SEDEMOGUN and Abdulsalami S. KOVO
Abstract: Aloji Kaolin was used as a combined sourced of silica and alumina to synthesize Zeolite A in this study. The raw Aloji kaolin was purified via sedimentation process to get rid of the underlying impurities such as quartz and this was then followed by metakaolinization at 800oC for 2h to incur reactive metakaolin phase. The purified and calcined kaolin were used to synthesize Zeolite A through conventional hydrothermal crystallization method. The synthesized Zeolite A was characterised by Scanning Electron Microscopy and X-ray diffraction methods. The synthesis parameters of Zeolite A synthesized through conventional hydrothermal route was 1M NaOH, crystallization temperature of 100oC and crystallization time of 6h after aging for 6h at room temperature. The synthesized Zeolite A was used for softening of hard water containing 76ppm of calcium ions for Gidan Kwano water sample and 178ppm of calcium ions for Maitumbi water sample, the synthesized zeolite A was able to reduce the hardness to 4ppm and 6ppm respectively for both water samples within 40 minutes of treatment. Zeolite A was successfully synthesized from Aloji kaolin and can be used for water softening.