Development and application of a novel approach to sand production prediction

Sand production is a complex problem that has plagued the oil and gas industry for decades, leading to reduced productivity, wellbore instability, equipment failure and expensive sand control and management techniques. Therefore, a reliable prediction of the potential of a formation to produce sand as well as the mass and volume of the sand produced is required for an appropriate and economically effective sand management. In this thesis a novel approach (yield energy model) to predict the potential of formation to produce sand and to quantify the mass of sand produced around yielded wellbore region based on energy dissipation is presented. During drilling and hydrocarbon production, yield and fragmentation of rock around a wellbore may occur when the rock is exposed to stresses which exceed its failure criterion, creating yield zone and hence the potential for instability and sand production. Generally, in brittle rocks, grains are deformed elastically with increasing stress, storing strain energy in the process. The stored strain energy is dissipated during failure, some of which is available for the fragmentation of the rock along failure surfaces. It is argued that the major source of sand production in competent rock is associated with the debris created by slippage along shear fractures in the yielded zone along perforation wall. The potential for sand production and the mass or volume of the sand created around the yield zone is predicted by quantifying the reduction in strain energy stored in the rock as its yields around a completion on removal of completion fluid and the imposition of drawdown. The resultant sand then becomes available as a source for sand production. The yield energy model has been applied to assess the potential of several reservoir samples to produce sand and also quantify the mass of the sand produced as a result of formation instability caused by drilling and hydrocarbon production in a field specific manner. Results from laboratory testing of representative samples and field data has been utilised as input parameters. The extent of the failed zone, the sand production potential and the mass of debris have been analysed as a function of mud weights, drawdown pressures and production rates. The impact of unique production performance of different horizons on formation stability has been accounted for by employing deliverability expressions. The results have been assessed with regards to field observations and were found to be consistent

Role of Exercise as a Residue for Maintaining Non-Communicable Diseases

The focus of this paper is on low regular, moderate- intensity exercise activities can benefits and have side effects on non-communicable diseases such as osteoporosis, diabetes, arthritis, hypertensions (BP) and so on, while these diseases are no infections, they nonetheless can occur in epidermis proportions. The global increase in chronic disease is drive largely by globalization, urbanization and rapid aging of populations. These determinants contribute to the three primary risk factors common to most chronic disease-unhealthy diet, inactivity and tobacco/alcohol use. Prevention and management of certain non-communicable diseases through a well-planned exercise programme were highlighted; conclusion and recommendations were also made

EFFECTS OF EXAMINATION ANXIETY ON UNIVERSITY STUDENTS’ ACADEMIC PERFORMANCE IN NORTHWEST UNIVERSITY, KANO, NIGERIA

This study examined the effects of examination anxiety on university students’ academic performance in Northwest University, Kano State, Nigeria. Descriptive survey design was employed. Purposive sampling techniques were used to select 350 respondents comprising of 203 male and 147 female students in the study area respectively. Data collection was carried out using Effects of Examination Anxiety Questionnaire (EEAQ) for students. The instrument was subjected to face and content validity by experts. Cronbach Alpha reliability was used to obtain 0.83 reliability index. To achieve the purpose of the study, two null hypotheses were formulated and tested. Data collected was analyzed using Mean Score, Standard Deviation and t-test Statistics at 0.05 level of significance using SPSS v16. Results obtained revealed that there is no significant difference between male and female students on causes as well as effects of examination anxiety regarding their academic performance. Based on the findings, the study recommended that counsellors as well as other educators should create enabling learning environment for students free of tension and unnecessary stress so as to minimize anxiety and amongst others.  Article visualizations

Electrochemical reduction of CO₂ to oxalic acid and other valuable C₂ chemicals

In recent years, there has been a growing interest and widespread adoption of electrochemical methods to address many of the energy and environmental challenges we encounter in modern society. This electrochemical approach encompasses a variety of highly adaptable techniques that often eliminate the need for harmful chemicals and extreme temperatures, aiming to offer an alternative to fossil-based compounds. In this thesis, we explore how electrochemistry can be harnessed for the development of a sustainable process based on electro-reduction. By showcasing the versatility of these techniques, our work covers a broad spectrum of approaches and analytical methods, with potential implications ranging from providing alternative pathways for industrially relevant chemical production to reducing reliance on fossil resources. Chapter 1 introduces the electrochemical reduction of CO2 to oxalic acid and other C2 chemicals. It explains the fundamental concepts of this approach, discusses the parameters affecting its efficacy, and provides an extensive account of its application in previous and recent years. Chapter 2 delves into the experimental techniques underpinning the research in this thesis. Chapter 3 details the application of benzonitrile as a catalyst to enhance the electrochemical reduction of CO2 to oxalic acid on the Pb electrode in propylene carbonate. Our findings indicate that the inclusion of benzonitrile in the electrolyte enhances the faradaic and reaction yields of oxalate/oxalic acid production, along with an improved area-normalized rate of formation. This achievement sets a record rate for oxalate/oxalic acid formation. Chapter 4 explores the electrochemical reduction of oxalic acid to glyoxylic and glycolic acids on a Ti-based electrode. Our findings reveal that the direct electrochemical reduction of oxalic acid to these compounds of industrial importance (glyoxylic and glycolic acids) can be achieved with a high yield at room temperature, facilitated by the native oxides of titanium (Ti/TixOy). Chapter 5 highlights the combined impacts of ultrasound and electrochemistry in the sonoelectrochemical reduction of CO2 on a copper electrode, aiming to produce valuable products. The findings reveal a compelling outcome, which tackles the issue of bubble formation on the electrode surface and mitigates charge transfer resistance by amplifying the mass transport of electroactive species through acoustic streaming and cavitation phenomena

Development of Quality Standards of Prosopis africana (Fabaceae) Stem-Bark

Prosopis africana (Guill. & Perr.) Taub. (Fabaceae) is the only known species of its genus found in Africa. Almost all parts of the tree are used in medicine namely as remedies for skin diseases, caries, fevers, gonorrhoea, tooth and stomach-ache, dysentery and bronchitis. It is therefore considered worthwhile to establish quality standard for the stem bark. Pharmacognostic standardization was carried out on the pulverized stem-bark and its anatomical section, by using standard experimental procedures to determine the macro and micro morphological characters, as well as other quantitative and qualitative parametres. The results of this study produced vital data that could be useful in setting some diagnostic indices that could be included in the preparation of a monograph of the plant stem bark. Keywords: Quality standards, development, stem-bark, Mimosoida

Assessment of municipal solid waste disposal options using analytical hierarchy process and life cycle analysis

Disposal of municipal solid waste (MSW) generated in the city of Johor Bahru has been one of the challenges to the authorities and the public. Population sizes and MSW generation rates are increasing every year. The two existing landfills which are located at Seelong and Tanjung Langsat, can no longer cope with the amount of the MSW. This imposes more negative burden on the environment and public health; thus calling for better MSW disposal alternatives. However, local authorities are confronted with problems, protests and resistance as well as financial constraints in choosing and implementing waste disposals facilities. Solving the problem involves a complex evaluation procedure because compromises and tradeoffs among stakeholders and other interest groups are difficult to reach. In the current study, two concepts, analytical hierarchy process (AHP) and life cycle assessment (LCA) were used. The objectives are to identify stakeholders’ opinion on MSW disposal (through visits, meetings, conferences and symposia sessions) and use AHP to structure those opinions in proposing disposal alternatives (landfilling, recycling, incineration, composting) along environmental, economic and social implications. LCA was finally conducted to assess environmental impacts of the disposals so that informed and sustained disposal decisions can be implemented. AHP results showed that habitat depletion, land use, stream ecology, air quality and flora & fauna dominated environmental concerns of the stakeholders. Capital cost, operation and maintenance cost, landfill capacity and regulation influence were the most critical criteria in economic factors. Concern for public health and safety, public awareness, cooperation among others were found to dominate the social factors. The four alternative disposal options (i.e. landfilling, recycling, incineration, composting) were assessed and ranked according to the preferences of the stakeholders. Incineration and composting were most preferred to landfilling and recycling. Landfilling was not preferred and was perceived to be most environmentally polluting, economically unsustainable and socially unacceptable by the stakeholders. LCA results showed that Landfill has the highest impacts among the selected environmental impact categories namely, global warming (992 kg Carbon dioxide eq), acidification (0.104 moles of Nitrogen or Sulphur-eq), photochemical ozone formation (0.686 kg Non-Methane Volatile Organic Compounds) (MNVOC) and eutrophication (0.104 moles of Nitrogen or Sulphureq); except for ozone depletion potential having the highest impacts (0.686 kg Chlorofluorocarbon 11-eq) in the incineration plan due to the presence of Chlorofluorocarbon-based chemicals utilized in flue gas purification. Incineration with energy recovery and composting with stable organic compost were found to have least environmental impacts. Finally, views of concerns of stakeholder on MSW disposal in Johor Bahru city were identified and modelled with AHP. Practical environmental performance of the disposal alternatives were demonstrated through the LCA. Combination of the concepts (i.e. AHP and LCA) revealled better information in sustainability of disposing MSW by incineration and composting. This can aid more guided information on selecting better MSW disposal alternatives. Thus it will be possible to avoid misunderstandings on MSW treatments e.g. incineration since the public are involved in the decision making processes

Growth and Development of Entrepreneurship in Nigeria: An Investigation of Microfinance from the Rural Settings

This study focused on the significance of microfinance to growth and development of entrepreneurship in rural settings of Nigeria. The study determined the role of microfinance on the economic development of the rural areas of Nigeria. For these purposes, survey research was explored, using well structured questionnaires. The universe of the study (80 respondents) consisted of 55 selected SMEs and 25 will-be entrepreneurs in some rural areas of Nigeria, particularly, Kogi State; and the sample size (67) was determined using Taro Yamane sampling method. Bowler’s proportional allocation method was further employed to ensure objective questionnaires distribution process. This study analyzed the data collected in tables with percentage method, and used Chi-Square for hypotheses testing. Findings revealed that microfinance is significant to the growth and development of entrepreneurship, and equally, economic development in the rural settlements of Nigeria. It was concluded that small scale agricultural practice and micro-small scale enterprises are developing in the rural settlements. This makes microfinance significant to the growth and development of entrepreneurship, and equally the economic development in the rural settings of Nigeria. The study therefore recommends that the government should design and implement policies and programmes that are capable of serving as road map for effective and efficient microfinance services in the rural settlements of Nigeria, and that entrepreneurs should carefully manage microfinance facilities to combat peculiar challenges facing their entrepreneurial activities and economic development. Keywords: Rural Entrepreneurs, Microfinance, Economic Development, Financial Products, Small Scale Enterprise

Isolation and Characterization of Palmitic Acid from Ethyl Acetate Extract of Root Bark of Terminalia Glaucescens

The aim of this study is to identify and characterized the bioactive compounds from the root bark of the plant. Preliminary phytochemical screening of the root bark extract of Terminalia glaucescens revealed the presence of steroids, terpenoids, saponins, flavonoids, tannins and cardiac glycoside. The plant has wide folk medicinal use in traditional medicine. The air dried root bark was pulverized to powder, subjected to hot extraction (soxhlet) with methanol, and fractionated into n-hexane, ethyl acetate, and n-butanol fractions. Ethyl acetate as bioactive fraction based on sensitivity test was subjected to TLC and column chromatography. The isolated compound was colourless powder, which was further subjected to IR, UV, 13CNMR and 1HNMR for proper characterization and elucidation of the structure. The compound was concluded as palmitic acid

Moderating effect of access to finance on total quality management, market orientation, entrepreneurial orientation of small and medium entreprises performance in Nigeria

Past literature reported a mixed influence of total quality management, market orientation, entrepreneurial orientation, and performance of small and medium enterprises (SMEs). Thus, suggesting the need for the incorporation and testing of the effect of a moderating variable due to the inconsistency in the research findings. To address this theoretical gap, the present study used resource-based view and pecking order theory to examine the moderating role of access to finance on the relationships between total quality management, market orientation, entrepreneurial orientation, and SME performance. The study employed stratified random sampling and self-administered questionnaire techniques in collecting data from SMEs operating in the Kano, Kaduna, and Sokoto states in the north-west geopolitical zone of Nigeria. Based on the response rate of 302 questionnaires, hypotheses were tested using Partial Least Squares Structural Equation Modelling (PLS-SEM). The findings of the study showed that total quality management, market orientation, and entrepreneurial orientation were significant predictors of SME performance. The results of the study also indicated that access to finance moderated the relationship between total quality management and SME performance. Also, access to finance moderated the relationship between market orientation and SME performance. A similar result was also found for the relationship between entrepreneurial orientation and SME performance. The study may benefit SME owners/managers, small and medium enterprises development agency of Nigeria (SMEDAN), manufacturers association of Nigeria (MAN), as well as governments at various levels. The study may also serve as a reference for future studies. Finally, the limitations, implications, and suggestions for future research are discussed

Investigating the Effect of Entrepreneurship Development on the Relationship between Market Orientation, Total Quality Management and SMEs Performance in Kano

This paper investigates the effect of entrepreneurship development on the Small and Medium Enterprises (SMEs) performance in Kano. The issue of Market Orientation (MO), Total Quality Management (TQM) on the Small and Medium Enterprises (SMEs) performance in Kano state will be an interesting area of research as a centre of commerce in Nigeria. The paper sample consists of 8,286 of all the SMEs operating in Kano state. Out of which 367 questionnaires were administered to respondents concerning the MO and TQM to SMEs performance, 297 were returned. The numbers of the valid questionnaires are 291. The data were analyzed using Partial Least Square Structural Equation Modelling (PLS-SEM) to determining the effect of the variables of the study. The findings of the paper indicated that entrepreneurship development factors: MO and TQM promoting SMEs performance in Kano state. The results showed a statistically significant positive influence of both MO and TQM to SMEs performance. The finding provides the government, policy maker, SMEDAN and SMEs owners/ managers with the important variables of this MO and TQM to SMEs performance in Nigeria. This paper also made some recommendations for future research