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High-performance materials, systems, and processes have necessitated the exploration of very high-temperature environments. Materials, particularly ceramics, which can withstand these high temperatures, have been extensively studied, even though enough emphasis has not been given to clays sourced locally in Nigeria, where there is an abundance. Also, stochastic optimization techniques has been employed to improve on system or carry out experimentation with minimal spend of resources and very high accuracy. This work extensively explored the refractory properties of blends developed from locally sourced clays (Mayo Ndaga and kachalla Sembe and Kona). The Taguchi optimization technique was employed to determine the effect of various quantities of the clays on the loss on ignition (LOI), refractoriness (RF), and firing shrinkage (FS) of the blends. It was discovered that the optimum (lowest) LOI, highest RF, and lowest FS were 11%, 1333 °C, and 0.48%, respectively. Analysis of variance also proved the significance of Mayo Ndaga on the RF and FS of the blends, with P-values of 0.038 and 0.000 at a 95% confidence level.

OBJECTIVES: The novel coronavirus disease-2019 (COVID-19) that emerged in China, is a highly transmittable and pathogenic viral infection caused by the severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2); the disease has been declared by the World Health Organization as a Public Health Emergency of International Concern. The unavailability of approved therapeutic agents or vaccines is of great concern. This study performed molecular docking and absorption, distribution, metabolism, excretion and toxicity (ADMET) analysis of some compounds isolated from Neocarya macrophylla (Sabine) Prance ex F. White (Chrysobalanaceae) against three targets of SARS-CoV-2 proteins (3C-like protease, spike protein, and papain-like protease). MATERIALS AND METHODS: Phytoconstituents isolated from N. macrophylla were screened against key targets of SARS-CoV-2 using Auto Dock Vina, while the ADMET analysis was performed using swiss ADME and pkCSM ADMET descriptors algorithm protocols. RESULTS: The in silico computational studies revealed that the compounds (catechin, catechin-3-rhamnoside, quercetin, and epicatechin) isolated from N. macrophylla can effectively bind with high affinity and lower energy values to the three target proteins of SARS-CoV-2. ADMET analysis was used to predict important pharmacokinetic properties of the compounds, such as aqueous solubility, blood-brain barrier, plasma protein binding, CYP2D6 binding, intestinal absorption, and hepatotoxicity. CONCLUSION: The findings of this study have shown that N. macrophylla contains potential leads for SARS-CoV-2 inhibition and thus, should be studied further for development as therapeutic agents against COVID-19.

The last four decades have witnessed extraordinary volatility in crude oil prices, and this has severe implications for the race toward achieving a net-zero carbon emission target by 2050. This thesis attempts to understand the dynamic behaviour of crude oil prices through four interrelated essays on the flipping behaviour of crude oil prices between contango and backwardation market conditions. The thesis revealed interesting findings by employing robust econometric estimation techniques and innovative ideas on weekly and monthly Brent and WTI spot and futures prices spanning from January 1986 to April 2021. The first research essay reveals that price discovery takes place in Brent spot and WTI futures markets, and volatility spillovers from spot to futures market in the Brent market whereas, in the WTI market, volatility spillovers from futures to spot market. The second essay reveals that WTI stays longer in the backwardation market state, but the contango market state has a more profound impact on the crude oil market. The third essay reveals that six major oil price structural breaks significantly impact the contango and backwardation market conditions. The essay also shows that on April 20, 2020, the oil price shock flipped the oil market from backwardation to contango. Finally, the fourth essay reveals that convenience yield and inventory have a significant asymmetric nonlinear impact on crude oil prices, in line with the central prediction of the theory of storage. Overall, the thesis has four main contributions. First, it is the first research work to systematically explore the theory and evidence of the flipping behaviour of crude oil prices between contango and backwardation. Second, it is one of the pioneering research works in using Markov Regime-switching models and in harvesting the information content of crude oil futures curves. Third, it is also the first research work to analyse the impact of oil price structural breaks on contango and backwardation market states. Finally, the thesis uses econometric estimation techniques to bridge existing research voids on price discovery, volatility spillovers, and lead-lag relationships in Brent and WTI crude oil markets.

Small scale poultry production plays a major role in bridging the protein deficit and sustain rural livelihood in Nigeria. A study was conducted to estimate the technical and scale efficiencies of quail (Cortunix coturnix japonica) production a strategy toward the provision of sustainable animal protein in Nigerian diets. Data Envelope Analysis (DEA) was used to sieve efficient and inefficient quail farmers and established optimize energy. Data were collected with the aid of structured questionnaire administered to 193 quail farmers comprising of 78 battery cage system (BCS) and 115 deep litter system (DLS) operators using a multi-stage random sampling procedure. The result showed that feed, fuels and electricity gulps 63.38, 24.53 and 7.76 % of the total energy input in BCS production unit and equally constituted 65.16, 23.97 and 5.32 % in the DLS production unit. Both BCS (65.71 %) and DLS (67.90 %) used more renewable energy compared with non-renewable component. The net energy of both quail production units were positive, hence energy were gained. The results revealed that the total energy use that could be saved by converting the present units to optimal conditions were 7.80 and 6.76 % for BCS and DLS respectively. The BCS farms thrive better compared with DLS considering the results of the three efficiency parameters. The renewable energy inputs usage must be sustain and if possible increase in both sectors in order to improve the low energy productivity and increase energy output and invariably return to quail farming.Keywords: Quail chick farmers, Battery cage system, Deep litter system, Renewable energy, Pure technical efficiency

The aim of this paper is to analyze risks in fish farming systems in Oyo and Kwara States, Nigeria. The primary data were collected using structured questionnaire with personal interview method by trained enumerators. The data collected belonged to the 2015/2016 production year. The total respondents (277) in the two states were separated to concrete pond fish farmers (123) and earthen pond fish farmers (154). Descriptive statistics, safety model and multinomial logit model were used to analyze the data. The results indicated that concrete system was more hired labour driven, relatively had higher formal education, and higher total investment and credit utilized compared to earthen system. The results of the risk preference revealed that of 123 respondents in concrete pond system, 52 % are risk preferring, 34 % are risk neutral and 16 % are risk averse, indicating better risk seeking compared with 154 respondents in earthen pond system with 21.4 % being risk preferring, 59.7 % being risk neutral and 18.8 % risk averse. The results of the estimates of the explanatory variables revealed that that the set of significant explanatory variables and their signs vary across the concrete and earthen pond systems. It would be concluded that the determinants of fish farmers’’ risk status differ considerably between concrete and earthen pond systems. Fish farmers needs to be sensitized through seminars, workshops and trainings in seeking risk by extension personnel in collaboration with agricultural insurance firms, this will go a long way in improving fish production among respondents.Keywords: Fish farming, Insurance, Marginal effect, Risk aversion, Workshops

Managing digital identities and access control for enterprise users and applications remains one of the greatest challenges facing computing today. An attempt to address this issue led to the proposed security paradigm called Identity and Access Management (IAM) service based on IAM standards. Current approaches such as Lightweight Directory Access Protocol (LDAP), Central Authentication Service (CAS) and Security Assertion Markup Language (SAML) lack comprehensive analysis from conception to physical implementation to incorporate these solutions thereby resulting in impractical and fractured solutions. In this paper, we have implemented Identity and Access Management System (IAMSys) using the Lightweight Directory Access Protocol (LDAP) which focuses on authentication, authorization, administration of identities and audit reporting. Its primary concern is verification of the identity of the entity and granting correct level of access for resources which are protected in either the cloud environment or on-premise systems. A phased approach methodology was used in the research where it requires any enterprise or organization willing to adopt this must carry out a careful planning and demonstrated a good understanding of the technologies involved. The results of the experimental evaluation indicated that the average rating score is 72.0 % for the participants involved in this study. This implies that the idea of IAMSys is a way to mitigating security challenges associated with authentication, authorization, data protection and accountability if properly deployed.

Cloud computing continues to dominate information and communication technology (ICT) strategies globally through the provision of remote access to computing resources via the internet. With its inherent pay-per usage model, flexibility, scalability and other features, cloud computing is also set to transform economic activities around the world. This paper analyses and compares the challenges facing the adoption of cloud computing from a geo-regional context; Europe and sub-Saharan Africa. An institutional theory perspective is used as framework for analysis. Findings from Norway in Europe and Nigeria in sub-Saharan Africa show that there are several challenges to cloud computing adoption in both places that are similar but impact on adoption decisions in different ways. For instance, the key adoption issues used as bases for comparison in Norway viz. security, privacy and trust, cost, Service Level Agreements (SLAs), government policies and regulations, and loss of control over data can all inhibit or pose as hindrances to cloud computing adoption. Contrarily, in Nigeria, these issues are not seen as inhibiting cloud computing adoption. Furthermore, the findings show the profound effect of normative and coercive pressures in Norway that can impact negatively on adoption decisions and theabsence of such pressures in Nigeria which seem to have a positive influence on adoption at present.Keywords: Cloud Computing; Adoption; Europe; Sub-saharan Africa; Institutional Theory

This study tests and measures the usability of mudah.my mobile application in terms of its efficiency, effectiveness, and satisfaction. Ten participants conscripted for the study performed five tasks on the application’s interface. A summative usability evaluation based on user performance and perception was carried out. The usability testing was conducted at Universiti Utara Malaysia (UUM) and the results obtained show that the Mudah.my mobile application is easy to use and consistent as seen from the analysis and observations made. However, the app is laden with some usability issues that should necessitate improvement. The study’s outcome will benefit developers and usability engineers in providing a user-friendly and usable application that meets users’ needs.