LAUTECH Journal of Engineering and Technology (LAUJET)
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PERFORMANCE EVALUATION OF ABESAN WASTEWATER TREATMENT PLANT
Get PDFThe performance of the Abesan wastewater treatment plant situated at the Abesan Low Cost Housing Estate, Abesan, Lagos had been evaluated. The treatment plant operates on biological treatment method (Activated Sludge Process) with an average wastewater inflow of 6 MLD has been considered for the case study. Thirty – six (36) grab samples of wastewater influent and effluent were collected over a period of six weeks during the dry and rainy seasons. The samples were analyzed for different wastewater quality variables. Average removal efficiencies of the measured parameters from the treated effluents were 96.3% for Chemical Oxygen Demand (COD), 93.3% for Biological Oxygen Demand (BOD), 92.4% for Total Suspended Solids (TSS), and 41.6% for Total Dissolved Solids (TDS) for the dry season. The rainy season average removal efficiency of the measured parameters were 96.8% for COD, 94.6% for BOD, 95.9% for TSS, and 38.6% for TDS. The values obtained for the dry season are lower than that obtained in the rainy season except for TDS. Most of the values of the effluent parameters exceeded the regulatory requirement of the Federal Environmental Protection Agency guideline for effluent limitation. The results obtained from this research conclude that regular routine de-silting and maintenance works of the plant be carried out to allow effective running of the plant
ANALYSES OF THE MOTION OF A PIPE CONVEYING A FLUID WITH AN INVISCID FLOW
Get PDFThe transverse motion of a fluid-conveying pipe with an inviscid flow was considered in this work. A comprehensive governing differential equation for the transverse vibration of a fluid-conveying pipe system was derived according to the principles of conservation of mass and momentum of fluid in a pipe. The derived equation was then analyzed and solved for an inviscid flow using the integral Fourier-Laplace Transformations. Effect of some flow parameters like mass ratios, damping coefficient and velocity of flow were investigated. Results revealed that the first natural frequency increased with increase in mass ratio for low velocities and reverse was the case for relatively high velocities. First natural frequency also increased with damping coefficients. Similar profiles can be observed about the second natural frequency. The response increased with increase in velocity. The study concluded that damping coefficient and mass ratio played significant roles in the motion of a fluid-conveying pipe with an inviscid flow
KNOWLEDGE OF ERGONOMICS AND ERGONOMIC RISK FACTORS FOR WORKERS IN THE CONSTRUCTION INDUSTRY
Get PDFConstruction is a physically demanding and potentially hazardous profession. The construction industry is characterized by fragmentation, multiplicity of operation, multiplicity of crews and industry culture. Ergonomics is still a relatively new theme for the construction industry. Understanding the ergonomic issues in construction can play a critical role in ameliorating its risks among the construction workers. Sustained physical work can be the cause of bodily injury to workers, which in turn entails enormous losses to the industry in terms of money, time, and productivity. Each of these however contributes to unforeseen and unfamiliar hazards or the unsafe behavior of workers. Several safety and health organizations have proposed rules and regulations that limit workers’ efforts in order to mitigate possible bodily injuries. Despite the advancement in technology the ergonomic knowledge has been slow in construction industry, however, physical efforts continue to cause serious damage to workers’ health and, as a result, efforts are being directed towards a more ergonomic and safe working environment. The aim of the paper is to discuss various ergonomic risks encountered by construction workers on construction sites and develop various interventions to reduce those risks. The paper also advocate for participatory research ergonomics as an effective health and safety policy in the construction industry so as to achieve the positive safety culture in the workers daily operations
GROUNDWATER QUALITY ASSESSMENT USING WATER QUALITY INDEX IN SOME PARTS OF ODEDA, SOUTH-WESTERN NIGERIA
Get PDFGroundwater quality samples were collected from boreholes and hand-dug wells located in some parts of the study area and were assessed for some physico-chemical parameters including pH, Electrical Conductivity, Total Dissolved Solids, total hardness, chloride, sulphate, nitrate, calcium hardness, magnesium hardness, potassium, iron and alkalinity. The results showed that most of the water quality parameters fell below the WHO maximum permissible limits with a few exceptions in about three locations. The quality indices were determined for each location and the values were found to be 20.86 – 57.40 indicating that about 75% of representative samples of the locations were good while about 15% was classified as poor. This can be attributed to high concentration of nitrates, EC, sulphates and total hardness in a few sample locations. The general low water quality index may have resulted from better sanitary conditions and improved living standards as well as the fact that the study was conducted at the peak of the rainy season. This type of assessment could be used as a powerful tool for making decisions and implementing water related policies as it documents water quality results that is easily understood by stake holders
ESTIMATES OF COST OF ACCIDENTS IN SOME SELECTED INDUSTRIES IN SOUTHWEST NIGERIA
Get PDFThe manufacturing industry is one of the most dangerous branches in light of the frequency of occupational accident. Direct and indirect losses generated by major manufacturing accidents reduce profit and cause management crises. Such losses significantly impact manufacturing business owners, workers, clients and the public. This research evaluated the effect of safety practices on operational performance of some selected manufacturing companies in Nigeria. Ten-year data were collected on yearly basis from four (4) manufacturing industries in Nigeria which are chemical, oil/gas, food/beverages, and metal/fabrication industries on annual record of accidents and annual expenditure on safety intervention programmes. The data were analyzed using existing mathematical models. The probability of each class of accidents has highest values estimated as: 0.19, 0.52, and 0.68 for fatal, serious and minor accidents, respectively while the lowest was estimated as: 0.03, 0.2, and 0.32 for fatal, serious and minor accidents, respectively. The highest accidents cost of potential consequences of accidents were estimated as N94,701,700, N13,339,567and N2,969,210 for fatal, serious and minor accidents, respectively while the least accidents cost was estimated as N541,072, N1,834,120 and N341,562 for fatal, serious and minor accidents, respectively. However, minor and fatal accidents in metal/fabrication industry has the highest (0.68) and the least (0.03) values of probabilities of occurrence of accident, respectively, while fatal accident in oil and gas industry has the highest cost of accident estimated as N94,701,700 (fatal accident) which is 93.21% of the total cost of accidents in the industry
BIO-BASED POLYURETHANE PREPARED FROM RENEWABLE FEEDSTOCKS
Get PDFNon-isocyanate polyurethane (NIPU)s were prepared by reacting carbonated soybean oil with kraft lignin using two pot reactions. In the first stage, epoxidized soybean oil (ESBO) reacted with carbon dioxide to form carbonated soybean oil (CSBO) with tetra-butylammonium bromide (TBAB) as the catalyst. In the second stage, urethane monomer was formed from the reaction of CSBO with 3-aminopropyltriethoxylsilane (APES) and was reacted with the kraft lignin. The reaction was catalyzed by lithium chloride and the NIPU was cured both at room temperature and at 70 oC. Effects of lignin composition (20 – 50 wt%) on the NIPU mechanical properties were studied. Fourier transform infrared spectroscopy (FTIR) analysis was used to determine the structure of the lignin, CSBO, and lignin polyurethane. Tensile strength of the NIPU was much more improved when the polymer was cured at elevated temperature compared to when cured at room temperature. On the other hand, room temperature curing favoured high elongation at break
INTELLIGENT TECHNIQUE FOR ELECTRICITY THEFT IDENTIFICATION USING AUTOREGRESSIVE MODEL
Get PDFVarious studies have investigated electricity theft, an illegally act, perpetrated to the detriment of the electricity power providers, however, less attention has been given to identification of the types of electricity theft. Data were acquired from the Consumer Load Prototype developed at two different levels using Sensor-A connected to the Pole Terminal Unit and Sensor-B connected to the Consumer Terminal Unit. The output of the sensors were connected to BNC-2110 device and linked to the PCI 6420E channel, which log the data in the computer for further analysis. LABVIEW (2012) software was programmed to acquires data at a sampling frequency of 500Hz and decimated at 10s interval before logging into the computer hard disk. The feature extraction of the data acquired was achieved using autoregressive technique and model order selectionwas based on minimum description length. The model coefficient AR (20), data acquired and predicted data were used for theft identification. Meter-bypassing theft was identified when the energy consumption from sensor A and sensor B are different, however sensor B reads zero value and there are disparities in the model coefficients. Illegal connection before the meter theft was identified whenever there is difference in energy consumption as evaluated form sensor A and sensor B and there is no zero value recorded from sensor B, while Meter tampering was detected when the energy consumption as evaluated form sensor A and sensor B are different and there are no disparities in the model coefficients
DESIGN, CONSTRUCTION AND PERFORMANCE STUDY OF AN ELECTRONIC BODY MASS INDEX INSTRUMENT
Get PDFThe design and construction of an electronic Body Mass Index (BMI) has been carried out in this study. The design calculates the BMI automatically by overcoming marginal errors. The design incorporates the functions of PING))) sensor, digital weight sensor into the system. C programming code was writing in programming a microcontroller that controls the whole design. The measured height and weight are processed by the programmed microcontroller which then generates BMI being display on a Liquid Crystal Display (LCD). The designed system was used to estimate the BMI of eight individuals of different gender. The performance evaluation of the system was compared with the four groups category cited by World Health Organization in the BMI chart
MODELING THE AIR FLOW RESISTANCE OF BULK SPONGE GOURD (LUFFA CYLINDRICA) SEEDS
Get PDFThe knowledge of airflow resistant of agricultural materials is important to the design of drying and aeration systems and enhances proper fan selection for these systems. This study investigated the pressure drop across a bed of sponge gourd (Luffa cylindrica) seeds at moisture contents in the range of 9.98 to 16.5% (w.b), airflow rate of 0.11 to 0.32 m3s-1m-2, material bed depth (0.2 to 0.8 m) and bulk density (loose, medium, and high). Pressure drop data was fitted to three common airflow resistance models (Shedd’s, Hukill and Ives’s, and Ergun’s models). An empirical equation comprised bulk density, moisture content, and airflow rate was also developed to predict the pressure drop of sponge gourd seeds. Results obtained indicated that the airflow resistance of sponge gourd seeds increased with increase in airflow rate, bed depth but decreased with moisture content. Increased bulk density resulting from loose to densely filled resulted in an increase in resistance to airflow. Shedd model was selected to be the best for predicting pressure drop across bulk sponge gourd seeds for all the condition studied due to its high value for Coefficient of Determination (R2) of 0.996 and a low root mean square error value (0.0279) compared to other models. The empirical equation developed predicted well the pressure drop with R2 and RMSE values of 0.950 and 0.264 respectively
PERFORMANCE EVALUATION OF AN IMPROVED ITU-R RAIN ATTENUATION PREDICTION MODEL OVER MALAYSIA EQUATORIAL REGION
Get PDFAttenuation due to rainfall is one of the most fundamental constraints on the performance of satellite links above 10 GHz. This work presents the results of rain attenuation measurement using radar data collected from MMD and DIDM Malaysia. The results were compared with newly improved ITU-R P530-16 and four other selected tropical rain attenuation prediction models. The statistical analysis showed that ITU-R P 530-16 has significantly addressed the problem of rain attenuation underestimation prediction as presented by older version of the recommendatio