Search

Enhancing heat and mass transfer efficiency is crucial for reducing energy consumption and mitigating environmental impact in various industries, including power generation, electronics cooling, and chemical processing. This study explores the impact of solar radiation, bioconvection, micropolar fluid properties, and nanoparticle and chemical reactions on a stretching surface. The research uses mathematical modeling and analysis to solve the 2-dimentional laminar bioconvection boundary layer flow of micropolar based nanofluids. The study concludes that bioconvection significantly enhances heat transfer and fluid flow characteristics, with heat generation and chemical reactions playing a crucial role. The thermophysical properties of the fluid, bioconvection parameters, and chemical reaction rates also have a significant impact on flow and heat transfer characteristics. The analysis reveals that increased heat generation leads to increased temperature, while chemical reactions decrease concentration flow. Unsteadiness parameters also impact velocity, energy, concentration, and microorganism. The findings can provide valuable insights for researchers and engineers in designing and optimizing heat transfer systems involving micropolar nanofluids with bioconvection, heat generation, and chemical reactions.

Cities in developing countries experience rapid expansion, which has a negative effect on the aesthetic value of the city. This paper thus examined urban metamorphosis and development control with the specific objectives of assessing the physical development between 1986 and 2018 and assessing residents' perceptions of development control regulation and challenges of development control enforcement as regards to road setbacks in Ile-Ife, Osun State. Landsat images were used to examine changes in the physical development (built-up) in Ile-Ife. A questionnaire and key informant interview were used to examine residents' perceptions of development control regulation and the challenges of development control enforcement. The result showed that built-up area increased from 2760.05ha (94.81%) between 1986 and 2002 to 6843.41ha (120.67%) between 2002 and 2018, and 9603.46ha (329.87%) between 1986 and 2018. Between 1986 and 2018, a recorded annual magnitude and frequency of 9603.46ha and 600.22 ha were built up. The study revealed that 60% of the informants confirmed that the planning authorities were grappling with inadequate funds and inadequate technical and manpower, which had resulted in their inability to undertake planning activities. The study concluded that rapid development had negatively affected development control in the study area. It is therefore recommended that the government strengthen the planning authority, subsidize the cost of plan approval, and provide easy access to building permits. [ABSTRACT FROM AUTHOR]

Planting espacement is a vital process which affects the quality of tree's growth and development but this information is lacking in Monodora tenufolia (a multipurpose species). This study aimed at obtaining the appropriate espacement for plantation of this species by subjecting seedlings to three (3) different espacement on field trial. Forty five (45) seedlings were selected and planted in 1m x 1m, 2m x 2m and 3m x 3m spacing. Randomized Complete Block Design was the experimental design used. Tending operations were carried out. Morphological parameters such as seedling height, diameter, number of leaves and number of branches and physiological parameters [Relative Growth Rate (RGR) and Absolute Growth Rate (AGR)] were assessed. Data collected was subjected to analysis of variance and descriptive statistics. Seedlings subjected to 1m x 1m spacing (77.01±4.7 cm) were significantly taller than in 2m x2m and 3m x3m spacing and had highest mean diameter at base (9.02±0.6), mean number of leaves (63.6±7.7) and number of branches with 6.89±0.9. Seedlings in 2m x 2m had highest values for both RGR (0.22 gg-1 wk-1) which was followed by 3m x3m (0.15 gg-1 wk-1) while least was observed in 1m x 1m (0.13 gg-1 wk-1) while highest mean value (1.55 g-1 wk-1) was observed in 3m x 3m while 2m x 2m had the least (1.22 g-1 wk-1). In conclusion, closer spacing (1m x1m) favoured the morphological parameters but wider spacing supported the physiological parameters (2m x2m and 3m x 3m). Therefore, wider spacing is recommended when seed production is the management objective but for ornamental, closer spacing can be considered with proper maintenance. [ABSTRACT FROM AUTHOR]

Cities in developing countries experience rapid expansion, which has a negative effect on the aesthetic value of the city. This paper thus examined urban metamorphosis and development control with the specific objectives of assessing the physical development between 1986 and 2018 and assessing residents' perceptions of development control regulation and challenges of development control enforcement as regards to road setbacks in Ile-Ife, Osun state. Landsat imageries were used to examine changes in the physical development (built up) in Ile-Ife. A questionnaire and key informant interview were used to examine residents' perceptions of development control regulation and challenges of development control enforcement. The result showed that built-up area increased from 2760.05ha (94.81%) between 1986 and 2002 to 6843.41ha (120.67%) between 2002 and 2018, and 9603.46ha (329.87%) between 1986 and 2018. Between 1986 and 2018, built up recorded annual magnitude and frequency of 9603.46ha and 600.22ha. The study revealed that 60% of the informants confirmed that the planning authorities were grappling with inadequate funds and inadequate technical and manpower which had resulted in their inability to undertake planning activities. The study concluded that rapid development had negatively affected development control in the study area. It is therefore recommended that the government should strengthen the planning authority, subsidize the cost of plan approval, and provide easy access to building permits. [ABSTRACT FROM AUTHOR]

Wood is hygroscopic and is considered dimensionally unstable materials when exposed to wet conditions. To increase the hydrophobicity of wood, this study focused on the modification of tropical hardwood (Triplochiton scleroxylon) along different positions of the stem using acetic anhydride The weight percent gain (WPG) was determined and acetylation reaction was confirmed with FTIR. The dimensional stability of the wood was characterized by water absorption (WA), volumetric swelling (VS), anti-swelling efficiency (ASE), and water repellent efficiency (WRE). Data obtained were subjected to analysis of variance at α0.05. It was observed that the weight gain (WG) by acetylation increases along the axial position (base to top) of T. scleroxylon wood. IR-spectra confirmed properly the substitution of the acetyl group. The treatment resulted in a marked improvement in the WA and VS, ASE, and WRE of acetylated T. scleroxylon wood were also found to improve considerably from base to top of the wood. It could be said that the WPG and hydrophobicity increased, but the percentage of water absorption and volumetric swelling diminished. Hence, the modified wood showed good hydrophobicity and improved dimensional stability. [ABSTRACT FROM AUTHOR]

Since commercial motorcycle and tricycle have become a recognized means of transportation in Nigeria, it has generated research interest among scholars with different focuses and findings. This paper examines the activities of commercial motorcycle and tricycle riders as a means of livelihood and their vulnerability to hazards associated with their works. The study was carried out in Orile-Iganmu Area, Lagos State, Nigeria. Twentyfive identified terminals for motorcycle and tricycle riders were purposively used for this study. Out of 250 registered motorcycle riders and 134 registered tricycle riders, 25% were randomly selected across the terminals. Thus, sixty-three motorcycle riders and thirty-five tricycle riders were sampled. Data collected were analysed using appropriate statistical packages. The findings also show that motorcycle and tricycle operators earn above 1.90 dollar per day but this does not escape them out of extreme poverty as the average number of household that depend on their income is high. This study infers that there is significant positive relationship between level of hazard risk, and vulnerability to accident. Hazard vulnerability can be minimized through construction of good roads, regular traffic control, compliance to traffic rules, and regular rest and medical check-up. [ABSTRACT FROM AUTHOR]