Communities in DSpace

Select a community to browse its collections.

Recent Submissions

No Thumbnail Available
Item
Open Access
Development of an Adsorption Solar Drying with Internet of Things- Based Control System.
(Department of Agricultural and Environmental Engineering, Faculty of Technology, Obafemi Awolowo University., 2023) Olagunju, Titilope Modupe
This study investigated the effect of different adsorbent filters on the relative humidity of air and selected the most appropriate filter. This study also developed and evaluated an IoT-based control system for possible use in solar dryers. An existing solar dryer was modified by introducing the selected adsorbent filter and the developed IoT control system. The performance of the modified solar dryer was evaluated and optimised by determining the effect of the drying kinetics of ginger slices on the quality of the dried products. These were with a view to enhancing the efficiency and effectiveness of the operation of solar dryers. The optimum specification of moisture adsorbent filter was obtained for four adsorbent materials (activated clay, activated charcoal, calcium sulphate, and silica gel). The data obtained for the effect of pack thickness, suction fan speed, and inlet air temperature on the air desiccation performance of the adsorbents was fit in polynomial models and optimised to select the best moisture filter. IoT-based control unit was designed using the Arduino Uno microcontroller, which was interfaced with temperature, humidity, and weight sensors, which were programmed to detect and transmit sensors data to cloud server. The selected absorbent filter as well as the developed control system were then incorporated into the existing mixed-mode solar dryer, and the effect of this modification on the drying kinetics of ginger slices was investigated using response surface methodology. Responses such as total time of active drying and equilibrium moisture content were used as performance indicators of the modified dryer. The optimal conditions for the operation of the dryer, was established and the quality (proximate, phytochemicals and colour) of ginger dried at optimum condition was also determined using standard experimental procedures. The results obtained indicate that silica gel was the most effective adsorbent filter under optimal conditions of 2.03 cm layer thickness, with no requirement for the suction fan. The temperature and relative humidity sensors of the control system were effective, with average accuracies of 98.84% and 96.23%, respectively. However, the weight sensor had an average accuracy of 80.04%. This indicated that the load cell used in the study was sensitive to heat, which adversely affected its accuracy. The performance of the modified solar drying system indicates that the modification significantly aided the drying process of ginger slices, with the best drying conditions being an adsorbent layer thickness of 0.5–1.5 cm and an air velocity of 0.5–2.5 m/s. These conditions resulted in the shortest drying time and a final moisture content of 9.83 to 12.14% wb, which is recommended for safe storage of dried ginger. Nevertheless, the most desirable optimum condition for operating the modified solar dryer was found to be an air velocity of 2.5 m/s and an adsorbent thickness of 1.22 cm, which resulted in a final moisture content of 10.72%. The modification of the dryer significantly influenced the proximate and phytochemical composition of ginger slices. This study concluded that the use of an optimised adsorbent filter and an IoT-based control system can significantly improve the drying process, reduce postharvest losses, and enhance the quality of dried agricultural products.
No Thumbnail Available
Item
Open Access
The challenges of eradicating diseases under sustainable development goals in Nigeria.
(Faculty of Administration, Obafemi Awolowo University,Ile Ife,Nigeria., 2024) Akinmameji, Ebunoluwa Omolola
The study examined the challenges militating against the implementation of Sustainable Development Goal (SDG) 3.3 in Nigeria. It also interrogates the ways in which international health partners are contributing to Nigeria’s ongoing policy thrust of goal 3.3 of the SDGs; and further analyses the implications of the challenges of Millennium Development Goals (MDGs) for the implementation of goal 3.3 of the SDGs. These were with a view to providing informations on the implications for Nigeria`s SDGs` pursuit and international health partners have been contributing towards this policy thrust. The study utilized both primary and secondary sources of data. Primary data were collected through the conduct of thirteen in-depth interviews with purposively selected strategic informants who were drawn from the Federal Ministry of Health,w Abuja; Office of the Senior Special Assistant to the President, Abuja; National Agency for the Control of AIDS (NACA), Abuja; World Health Organization (WHO), Abuja; World Health Organization (WHO), Akure; Ministry of Urban and Regional Planning, Oyo State; Ministry of Urban and Physical Planning, Ondo State; Ondo State Agency for the Control of AIDS (ODSACA); Oyo State Agency for the Control of AIDS (OYSACA); Sustainable Development Goals Office, Lagos State; Ministry of Health, Lagos; Ministry of Health, Oyo State; and Ministry of Health, Ondo. Secondary data were obtained from textbooks, reports, articles, journals, internet sources, and relevant internet materials that contribute meaningfully to the overall objective of this research work. Data collected were analysed using content analysis. The study reveals that there are several critical factors militating against the eradication of HIV/AIDS, tuberculosis, and malaria in Nigeria, and these are majorly categorized under human, capital, and technical factors. These factors include resource inadequacy, lack of proper monitoring and documentation, poor environmental sanitation and control, low level of awareness, and socioeconomic status. While the human factors are majorly attributable to citizens’ actions and inactions, the capital factor is largely a derivative of government actions, while the technical factors stem from the institutions involved in the implementation of goal 3.3. Likewise, the study discovered that international bodies such as the World Health Organization (WHO), United Nations’ Children Fund (UNICEF), the Joint Nations Programme on HIV/AIDS (UNAIDS), and President’s Emergency Plan for AIDS Relief (PEPFAR) are agencies that actively contribute in areas such as funding, support structure, and technical assistance in the eradication of HIV/AIDS, tuberculosis and malaria. The study further reveals that although the challenges that faced the implementation of the MDGs are still much in place, the SDG has achieved a substantial rate of progress as compared to the MDGs. Likewise, it was discovered that efforts have increased in ensuring that the challenges faced by the MDGs serves as a leverage for the implementation of The study therefore concludes that challenges to the successful eradication of communicable diseases in Nigeria are weaved around human, capital, and technical factors. However, there has been no significant progress in reducing the prevalent rate of communicable diseases except for HIV and also the inability of early detection and treatment results in a slow rate of progress in combating tuberculosis.
No Thumbnail Available
Item
Open Access
Fiscal dominance and economic performance in Nigeria (1980-2020)
(Department of Economics, Faculty of Social Sciences, Obafemi Awolowo University., 2023) Idowu, Ajayi olanike
The study examined the nature and extent of fiscal and monetary policy dominance in Nigeria as well as the degree of fiscal dominance or monetary effectiveness in Nigeria. The study also examined the sustainable level of fiscal deficit with respect to the economic performance in Nigeria within the period of 1980-2020. These are with a view to examining the relationship between fiscal dominance and economic performance in Nigeria. Annual time series secondary data for the period of 1980-2020 were employed in the study. Data on fiscal deficit, public debt, government expenditure, money supply, interest rate, and real Gross Domestic Product (GDP) for the study period were obtained from the Central Bank of Nigeria (CBN, 2020), and the World Development Indicators (WDIs, 2020) sourced from the World Bank. The study used descriptive statistics in form of tables, charts and graphs for the trend analysis. The study also adopted Dynamic Ordinary Least Squares (DOLS) for long run analysis, while threshold regression was also conducted for the measurement of sustainable level of fiscal deficit in Nigeria. It was established in the study that government expenditure and outstanding debt have significant positive relationship with money supply. Specifically, N1 billion increase in public debt is expected to increase money supply by N1.2 billion (t = 8.2446, p < 0.01). Similarly, N1 billion increase in government spending will cause money supply to increase by N1.36 billion (t = 4.2850, p < 0.01). Conversely, interest rate exhibited negative effect on money supply, such that one percent increase in interest rate will bring money supply down by 150 percent (t = -2.0113, p < 0.05). The study also revealed the sustainable level of fiscal deficit in relation to economic performance in Nigeria. Specifically, the results showed that when fiscal deficit is lower than N34.4072 billion, it will decrease economic output by N34.7001 billion. (t = 3.21, p < 0.01) and that when fiscal deficit is higher than N34.4072 billion and lower than N1,923.637 billion, it will not only have a positive impact on economic performance but it will also increase economic output by N4.0023 billion (t = 3.69, p < 0.01). The study concluded that, though there is co-movement between fiscal and monetary authority variables, there is no fiscal dominance in Nigeria.
No Thumbnail Available
Item
Open Access
Isolation, characterization and bioactivity studies of the extract from aerial part of hilleria latifolia (LAM)
(Department of Chemistry, Faculty of Science, Obafemi Awolowo University, Ile-Ife., 2023) Arowosegbe, Sunday Micheal
This study screened the crude extract of Hilleria latifolia for its phytochemical constituents and evaluated the extract and fractions for their antioxidant and antibacterial activities. It also isolated compound from its active fraction and elucidated the structure of the compound. The antioxidant and antibacterial potential of the isolated compound were also determined. These were with a view to finding novel bioactive compound from this medicinal plant. The aerial parts of the plant was air-dried and pulverized. The pulverized plant was extracted with 90% methanol/water for 96 hours and filtered. The filtrate obtained was concentrated to dryness in vacuo at 40 ℃. This afforded the crude extract which was subjected to solvent partitioning using solvents of varying polarities: n-hexane, dichloromethane and ethyl acetate in turn. This yielded four solvent fractions, and the aqueous MeOH fraction inclusive. The crude and the solvent fractions were tested for antibacterial activity, Total Phenolic Content (TPC), Total Flavonoid Content (TFC), and antioxidant activities using a number of antioxidant assays namely: 2,2-Diphenyl-1-picrylhydrazyl (DPPH), Nitric Oxide (NO) Scavenging, Metal Chelating Ability (MCA), Ferric Reducing Antioxidant Power (FRAP) and Total Antioxidant Capacity (TAC). The antibacterial activity was evaluated using the Agar diffusion method. The results showed that of all the solvent fractions obtained, the ethyl acetate fraction was the most active in the DPPH, TAC, MCA, and FRAP assays. One compound was isolated from the aqueous fraction using column chromatography. The isolated compound, HLA-1 was characterized by Nuclear Magnetic Resonance (NMR) and Infrared (IR) spectroscopy. Compound HLA-1 was identified as 8 – methyl – 1, 4 – oxazo – 2 – enine – 5, 7, 9 – trione. The n–hexane and dichloromethane fraction obtained from the crude extracts of Hilleria latifolia exhibited significant biological and antioxidant activities. These fractions were subjected to GC – MS analyses and a total of 27 compounds were identified in both fractions. Most of the identified constituents have been reported to possess various biological activities such as antioxidant, anticancer, anti-inflammatory and antibacterial activities. The study concluded that the extracts and isolated compound from Hilleria latifolia exhibited varying degree of antibacterial and antioxidant activities and could be effective in the management of infectious and oxidative stress related diseases. These observed activities could justify the ethnomedicinal uses of the plant.
No Thumbnail Available
Item
Open Access
Viability of online guidance and counseling service at the Obafemi Awolowo University, Ile-Ife
(Department of Educational Foundations and Couselling Service, Obafemi Awolowo University, 2013) Adebowale, Olusegun Fatai
The study examined the disposition of students toward online guidance and Counseling services in the Obafemi Awolowo University. It investigated the students' preference for online counselling in terms of media of communication. It also examined the students' preferred mode of entry into online counselling, the prevalent concerns presented by them as well as the problems confronted during online counselling sessions.