LAUTECH Journal of Engineering and Technology (LAUJET)
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PROPOSAL OF NEW TWO-PARAMETER ESTIMATOR FOR GAMMA REGRESSION MODEL WITH CORRELATED REGRESSORS
Get PDFMulticollinearity among the explanatory variables in the gamma regression model, make the usual maximum likelihood estimator (MLE) for estimating regression parameters in the multiple regression analysis inefficient as the variance of MLE is high and unstable. In recent times, some researchers have proposed estimator based on ridge and Liu biasing parameters to handle the problem of multicollinearity. This paper proposes new two parameter estimators in gamma regression models when there is collinearity among the explanatory variables. Conditions under which the proposed Gamma Modified New Two-Parameter (GMNTP) has better performance are established theoretically and simulation studies were also conducted. Both simulation and real life application results show that, GMNTP estimator with shrinkage parameter has better performance than the existing estimators in terms of MSE.
 
Production and purification of biogas from poultry dropping at mesophilic temperature
No full textBiogas is a mixture of gases produced during the breakdown of biodegradable organic matter in the absence of oxygen. Problems of impurities such as Carbon dioxide (CO2), Hydrogen sulphide (H2S) and moisture have to be removed in order to improve the quality of biogas. This study aimed at upgrading the biogas produced from poultry dropping. The Poultry Dropping (PD) used as substrate was collected from Ladoke Akintola University of Technology, Ogbomoso (LAUTECH) poultry farm. The Continuously Stirred Tank Reactor (CSTR) available in the Agricultural Engineering Laboratory LAUTECH was used for biogas production. The biogas produced was analyzed using Gas chromatography, AGILENT 6890 before and after purification. The produced biogas was purified using chemical absorption. Distilled water, Silica gel and Iron fillings were used as the scrubbers to remove CO2, moisture and H2S, respectively. The CH4, CO2 and H2S of biogas production before and after purification were 61.42%, 35.83% and 0.67 %; and 89.81 %, 8.22 % and 0.54 %, respectively. The results revealed that the purified biogas has better advantage for cooking over the raw biogas.
 
Optimization of the effects of process parameters on nutritional and microbial qualities of canned snail meat using Taguchi method
Get PDFSnail farming being a low cost farming process that requires minimal professional skill requirements has gained more attention in recent times. Snail meats are rich in protein but are vulnerable to microbial contamination due to their habitat. Smoking and drying are the most common method of preserving snail meat in Africa, especially Nigeria. The quest to retain the nutritional value of snail meat while preserving it fresh has necessitated further investigation. Fresh snail meats were preserved by canning in three packaging media (brine, vinegar, brine-vinegar). The effects of canning time, temperature, nitrite concentration and packaging media on protein content, fat content, moisture content, ash and pH were investigated using Taguchi model. Statistical analysis was carried out. Process parameters were also optimized and validated for effective snail meat canning. Temperature was discovered to be the most controlling parameter for the variation in protein, fat and moisture content. Carbohydrate and ash content were not significantly affected by the process parameters. The optimum canning process parameters, 50 mins, 121?, brine and 100 ppm sodium nitrite concentration gave 18.98% ±0.11 protein content, 1.51% ±0.09 ash content, 1.40% ±0.04 fat content, 1.88% ±0.13 carbohydrate content, 76.23% ±0.08 moisture content and pH of 5.93 ±0.06. The absence of heterotrophic bacteria, fungi, coliform and Staphylococci in the validation experiment confirmed the efficiency of the optimum conditions and its suitability in the commercial preservation of canned fresh snail meat
Optimization of process parameters for adsorption of chromium (VI) from tie and dye industry waste water using banana peels activated carbon: response surface methodology approach.
Get PDFTopical researches have related the use of synthetic adsorbent for treatment of waste water with some neurotoxic and neurodegenerative diseases. With reference to this, the current study focused on the use of an agricultural by product and eco – friendly natural activated adsorbent, banana peels for the treatment of tie and dye industrial waste water. In a bid to obtain an optimum percentage amount of chromium (VI) adsorbed by the adsorbent and permissible level of chromium (VI) that should be discharged to environment, optimization of process variables affecting the adsorption of chromium (VI) was undertaken using a response surface methodology (RSM). Four parameters were carried out viz; mass of adsorbent, pH of solution, temperature and contact time and their effects on the adsorption of chromium (VI) on the tie and dye waste water were established. The obtained experimental data was fitted to a quadratic model that was also validated. The model predicted 95.496 % of chromium (VI) adsorbed with optimal conditions of 71.0 oC, 5.41, 76.58 minutes and 1.009 g for temperature, pH, contact time, and mass of adsorbent respectively. These conditions were validated in triplicates with 96.5 % chromium (VI) adsorbed. The results acquired from this work can be applied to industrial scale for waste water treatment.  
The Corrosion inhibitory performance of hybridized rice-husk extract and biopolymer waste on food-compatible mild steel in acidic media
No full textMetal corrosion is frequently the outcome of the reactive interaction between food's corrosive components and metal alloy during processing and packaging. This study used gravimetric and depth of attack methodologies to examine performance of hybridized rice husk extract and chitosan, as a corrosion inhibitor for mild steel in 1 M HCl. Rice husk was subjected to phytochemical screening in order to choose the best material combination. Gas chromatography–mass spectrometry was then used to characterize the extract. Fourier transform infrared spectroscopy was used to characterize the corrosion film solution and chitosan synthesized from residual biopolymer fish scale. The rate at which the coupon corroded with and without rice husk extract and chitosan was assessed in relation to temperature, concentration, and time. The formation of a film over the metal surface was facilitated by the presence of polycyclic chemicals, tannins, and cellulose, thus aiding corrosion. Inhibition efficiency increased with increase in temperature and concentration of rice husk extract. Kinetic parameters showed that Langmuir isotherm is the best fit because the R2 value is close to unity. The addition of 5:1 ratio of rice husk to chitosan shows a great difference as the inhibition efficiency increase with increasing temperature to 80% inhibition efficienc
Construction of ternary diagram for liquid-liquid extraction process using computer-based program
Get PDFThe Liquid-Liquid Extraction (LLE) is a liquid-liquid phase mass transfer process in which solute chemicals are transferred between two immiscible or partially miscible liquids due to difference in solubility of the solutes in the two liquids. The phase equilibrium relationships are generally inconvenient to handle algebraically, therefore, LLE computational analyses are usually made graphically. Manual construction of ternary diagram becomes cumbersome, tedious and time consuming when used for a process that requires large number of stages. Therefore, the aim of this work was to develop a customized computer package for the ternary diagram. The customized computer package for the ternary diagram construction was achieved with the use of fuzzy inference system toolbox and primitive line function in MATLAB. The computer program was test-run using data from literature to determine theoretical number of stages for a given LLE separation process. The result compared well with the existing literature result. 
Affordable and sustainable clean energy generation potentials from municipal dumpsites: case study of Oke saje dumpsite, Abeokuta, Ogun State, Nigeria
Get PDFThe operating method of final waste disposal in Oke saje area of Abeokuta is direct open dumping and burning. This study was conducted at a major dumpsite in Abeokuta, to investigate the existing waste management systems, characterize solid wastes generated, and estimate for the sustainable energy generation potentials.
Exploratory study design was adopted for a period of six (6) months, May to November, 2023. Seven (7) randomly selected plots of 1sq.m were located on Oke saje dumpsite, from where solid wastes were collected from top to the depth of 300 mm. Waste components were weighed to obtain the weight-based characterizations. Sorting into major waste components was in accordance with College and University Recycling Council (CURC) grouping system with modifications to accommodate peculiar waste stream generated in Oke saje dumpsite. Waste samples were taken to laboratory to carry our necessary physical, chemical and proximate analyses.
Estimated total solid waste generation in Oke- saje, dumpsite was 3,718,832.03 kg (3718.83 tonnes). Estimated energy content of solid wastes was 46370.47MJ. This implies that there is possibility of electricity generation up to 12.881MWh from daily steam production. An integrated solid waste management concept adoptable to Oke- saje, dumpsite, has zero waste concept of about 46 % waste material recyclable (from composting, bio-fuel production and recyclables), with electricity generating potential of 5.923 KWh and 56 % energy recovery (from electricity generation, incineration-derived ash and residual ash for landfilling or soil enhancement), of about 6.956 KWh.
Considering the high material recyclability, reusability and energy recovery potentials from solid wastes generated from Oke saje dumpsite, it was recommended that the Ogun State Waste Management Authority adopts affordable, sustainable and integrated waste management options of waste minimization and sorting from the source, reuse, recycling, and incineration of solid waste generated from the large communities within the state
Characterization and acid leaching beneficiation studies of Anka (Zamfara State, Nigeria) copper ore deposit
No full textThe chemical and mineralogical characterization of the Anka copper was examined and its susceptibility to H2SO4 acid leaching was assessed. A crude sample of the ore, weighing 5 kg, was sourced from the mines, communiated, homogenized, and characterised the crude sample. A 100 g fraction of the crushed sample was subjected to fractional sieve analysis and each sieve retained was chemically analysed. The leaching process was carried out on 100 g of -125+90 µm sieve size fraction using H2SO4 acid and the resulting product was chemically analyzed. The characterization result reveals 42.271% CuO using the energy dispersive x-ray fluorescence spectrometer and the x-ray diffractometer shows that the ore is mainly composed of Cu-carbonate hydroxide in the form of malachite mineral. The scanning electron microscope micrograph suggests that the ore contains dispersed grains of sodium aluminium silicate and copper carbonate hydroxide in a silica-dominated matrix. The ore's liberation size was determined to be at the sieve size of -125+90 ?m. Finally, the ore was discovered to be responsive to the H2SO4 acid leaching operation, leading to an enrichment of the feed from 42.27% Cu to a pregnant solution of 52.51% Cu and the residue from the leaching was analyzed to be 4.69% Cu
Development of an IOT based mobile robot for hazardous gas detection
Get PDFThe escalating concerns regarding environmental safety and the potential hazards posed by poisonous gases necessitate innovative approaches for efficient detection and monitoring. This paper introduces a novel solution in the form of a remote-controlled mobile robot equipped with advanced gas-sensing technologies. The robotic system aims to autonomously navigate hazardous environments, identifying and quantifying the presence of poisonous gases in real time. The methodology involves the integration of state-of-the-art gas sensors on the four wheeled mobile robot, enabling it to perform comprehensive gas detection while being remotely controlled for optimal safety. The paper details the design and implementation of the mobile robot sensors and navigational controls, emphasizing its adaptability to various terrains and its ability to transmit real-time data to an Internet of Things (IOT) application. Results from experimental trials demonstrate the efficiency and effectiveness of the proposed system in detecting and mapping poisonous gas concentrations, providing a valuable tool for environmental monitoring and emergency response
REBOUND RESILIENCE AND HEAT BUILD-UP OF HYBRID CARBON BLACK/SILICA-REINFORCED SOLID TIRE TREAD COMPOUND CONTAINING GROUND TIRE RUBBER OF DIFFERENT PARTICLE SIZES
Get PDFThe effect of addition of 20 phr ground tire rubber (GTR) of 40, 60, 80 and 100 mesh sizes in hybrid carbon black/silica (CB/SiO2) reinforced solid tire tread compound on the rebound resilience and heat build-up was investigated. The hybrid filler reinforcement was in the ratio of 50/10. Two-step mixing utilizing an internal mixer and two-roll mill was employed for the mixing, while vulcanization was carried out at 150. Results show that additional GTR lowered the rebound resilience and increased the heat build-up of the vulcanizates with the 100 mesh size GTR impacting the most adverse effect on the vulcanizates. The use of hybrid CB/SiO2 reinforcement helped in the recovery of some of the lost rebound due to the addition of GTR in the matrix. The use of hybrid CB/SiO2 reinforcement contributed to only a slight reduction in the heat build-up of solid tire tread compound containing 20 phr of GTR