Digital-Rock-Physics Modelling of Carbonates and Sandstones

This thesis seeks to investigate the influence of porosity and pore geometry on the macroscopic parameters of a porous rock saturated with fluid. These macroscopic parameters, also known as Biot's parameters, include the drained and undrained bulk moduli which characterize the rock’s resistance to compression (or expansion), the pressure parameter needed to increase the fluid content by a unit value at constant total dilatation, and the so-called Biot-Willis coefficient. This study also seeks to examine the effects of porosity and pore geometry on the stored solid elastic energy in the rock. To achieve these goals, I develop numerical simulations of compression tests of digital rock models. These simulations allow me to calculate Biot’s parameters for samples with known pore geometries. The numerical model results are shown to be in good agreement with an analytical model for a spherical rock sample with a single spherical pore. I investigate the variation of the macroscopic parameters as a function of the porosity and of the solid and fluid material properties. In particular, I show that, apart from the Biot-Willis coefficient, the other macroscopic parameters, as well as the total and compression solid energy densities, decrease with an increase in porosity. Whereas Biot's parameters are generally influenced by both porosity and pore geometry, the pressure parameter is only influenced by porosity but remains the same regardless of changes in pore geometry. Also, the results reveal that the carbonate pore geometries have some similarity to the simple pore geometries but are generally softer, while sandstone pore geometries are even softer than carbonate ones

ASSESSMENT OF THE POTENTIAL HEAT STORED IN THE DEEP AQUIFERS OF THE WILLISTON BASIN FOR GEOTHERMAL ENERGY PRODUCTION

As the world shifts from fossil based energy generation towards renewable energy, it is important to consider the role geothermal energy can play in Saskatchewan. The deep reservoirs of the Williston Basin possess some geothermal qualities that can be harnessed for direct purpose (heating and cooling of buildings) and for electrical power generation. Previous studies have looked at this potential at a large scale, however, this research focused on the moderate temperature geothermal resources (80-150oC) within two deep reservoirs, one formed by the Deadwood and Winnipeg formations of the upper Cambrian to Mid-Ordovician age and another consisting of the Red River and its stratigraphic equivalent, the Yeoman Formation of the Upper Ordovician age. This thesis uses the production and injection data acquired from the numerous hydrocarbon and waste disposal wells within Saskatchewan to quantify the probable heat and thermal power associated with hot waters historically produced at the basin scale. The research quantified electrical geothermal power within the reservoirs using three different techniques: 1) observed production rates; 2) maximum production rates (using well hydraulics); and 3) rock thermal volume. For the first technique, the production or injection rate for each well within the reservoirs of Deadwood-Winnipeg and Red River-Yeoman was extracted from well production or injection history data. A simple thermal equation was used to estimate the thermal power that could be generated from each well. The results show that, on average, each well within the DeadwoodWinnipeg reservoir and Red River-Yeoman reservoirs can generate thermal power valued at 0.4 MWt and 10 MWt respectively. The second technique used the well hydraulics, core analysis data and literature values to calculate the maximum possible values for production rates using the Cooper-Jacob empirical equation. The Gringarten and Sauty model was used in conjunction with these results to determine the required well spacing. The results show that the average well within Deadwood-Winnipeg and Red River-Yeoman reservoirs can generate thermal power of about 101 and 105 MWt respectively. The final method estimated the geothermal power by calculating the volumetric heat capacity of the geothermal reservoir with respect to the area of the reservoir between the production and injection wells, thermal properties and the thickness of the reservoir. The results show that, on average, the entire reservoir based on the Gringarten and Sauty estimate for well spacing has the capability of generating geothermal power of about 170 MWt for sandstone (Deadwood-Winnipeg) and 286 MWt for the carbonate (Red River-Yeoman) reservoirs. This method overestimated the geothermal power that can be generated from the entire volume of the reservoir based on well spacing. However, when a recovery factor is added into the equation, it gives values that are reasonable and comparable to those estimated from theoretical production

Continuity of Care for Chronic Non-Communicable Diseases Among Refugees: Challenges and Opportunities

Purpose: To review and document the challenges faced by different stakeholders - refugees, humanitarian organizations and host countries of refugees in accessing and providing continuity of care (management, informational and relational) for chronic non-communicable diseases among refugees. Method: A scoping review of the literature was conducted. Grey literature sources and academic databases such as PubMed, CINAHL, Web of Science, PsycINFO, Global Health, ELDIS Gateway to Development Information, Canadian Health Research Collection were searched from January 2006 to July 2016, focusing on refugees (and other key words) and chronic non-communicable diseases. Thematic analysis of the articles was conducted inductively. Results: The search yielded a total of 3,771 articles, of which, 40 articles met the inclusion criteria and were included in the final review. The emergent themes were categorized under the three areas of continuity of care for each stakeholder in the humanitarian context. Some emergent themes or challenges include language barriers, low socio-economic status, lack of sustainable financing and international aid, clinical management failures, competing priorities, low education and literacy levels, lack of research and robust data. An awareness of these challenges provides opportunities for reform of research, policy and clinical practice to ensure the prompt, optimal and sustained care of chronic non-communicable diseases among the refugee population. Conclusion: The findings of this review highlights the interconnected challenges of accessing and providing continuity of care for chronic non-communicable diseases among refugees. Further and more contextualized research of the topic and actions are to be taken to overcome the identified challenges and gaps in order to create a more holistic approach to the effective planning, implementation and delivery of health care services to refugees with chronic non-communicable diseases

Yam production in some South East and North Central zones of Nigeria beyond COVID-19 for acceleration towards inclusive sustainable development

This study evaluated the effect of socio-economic characteristics of small-scale yam farmers on the productivity and income levels of yam farmers beyond COVID-19 in some part of yam producing areas of South East and North Central zones (Benue, Ebonyi, Enugu and Kogi States) of Nigeria. Respondents (200) were selected by random sampling using a structured questionnaire. Data were analyzed using descriptive and correlation analysis. Majority of the respondents (71.7%) were male. COVID-19 will have serious negative impacts on the productivity and income of the yam farmers due to sex difference in angiotensin converting enzyme (ACE) 2 receptor and transmembrane serine protease 2 TMPRSS2 regulations. Majority (34.8%) of the respondents were within the age range of 55-64 years which might place them at increased risk of severe impact from COVID-19. Most of the respondents (37.9%) were with First School Leaving Certificate (FSLC) which will be aggravated by global lockdown of education institutions. COVID-19 pandemic has created the largest disruption of education systems due to closure of schools and other learning spaces as well as inability of many parents to work making financing of education to face big challenges. Most of the respondents (35.4%) had farm size of three hectares. Most of the respondents (37.9%) earned between ₦151,000 and ₦200,000 per hectare. This income informal economy will be affected by COVID-19 control measures. Majority of the respondents (70.2%) had between 21 to 30 years of yam farming experience. At this length of experience, it is expected that they will be within the age range that is more vulnerable to COVID-19 pandemic. Using Pearson correlation coefficient to assess the relationship between socio-economic factors farm characteristics of small-scale yam farmers establishes that farm experience significantly (p < 0.05) correlated with age of the respondents. Marital status was significantly (p < 0.05) correlated with age (0.548) and farm experience (0.932) of the respondents. Key words: yam farmers, socio-economic factors, productivity, small-scal

The Effects of Childhood Social Support and Family Resiliency on Mental Health in Adulthood

The effect of social support on the overall health and quality of life in adulthood has been well documented particularly in chronic disease populations. Very few studies examined the relationships between childhood social support, family resiliency and mental health in adulthood in the community and among disadvantaged minority populations. We examined the role of social support and family resilience during childhood on subsequent mental health-related quality of life (HRQoL) in adulthood among racial/ethnic minorities. A needs assessment survey which was designed to explore health determinants and quality of life indicators using a community-based participatory research (CBPR) approach in a low-income community in Tampa was analyzed. Participants were predominantly low-income non-Hispanic black and Hispanic population (n=187). The outcome mental HRQoL was measured using the validated Centers for Disease Control and Prevention’s (CDC) “Healthy Days Measure” instrument. We utilized sequential multivariable logistic regression models to examine the independent effects of childhood social support and family resiliency on mental HRQoL in adulthood. Approximately 12.3% of study participants reported poor mental HRQoL (i.e. ≥14 unhealthy days due to mental health). Childhood social support and family resiliency were significant predictors of mental HRQoL in adulthood, after controlling for sociodemographic characteristics. Sleep and composite health issues in adulthood were also associated with mental HRQoL. Our analyses highlight an opportunity to promote mental health through support of interventions that improve positive family relationships and reduce the burden of chronic health issues among non-Hispanic black and Hispanic children

Cognitive competencies of TVE students as correlates of entrepreneurial intentions

In the face of the global economic challenges facing countries in the world and considering the fact that Nigeria is in a very critical phase of its development, it is imperative to produce graduates with high entrepreneurial intentions so as to salvage the already comatose economy. The study attempts to ascertain the relationship between cognitive competencies of Technology and Vocational Education (TVE) students and their entrepreneurial intentions. Six hypotheses were tested. The study adopts a survey design and 350 TVE students from tertiary institutions across the South-East region of Nigeria are studied. Purposive sampling method is used in selecting the sample for the study while a structured questionnaire is used for data collection. The instrument for data analyses is the Bivariate Pearson Correlation matrix and the simple linear regression tools. The study found out the creative skills, critical thinking skills and problem solving skills are significantly correlated to entrepreneurial intentions of TVE students

Inculcating Digital Contents, Technological Tools: Agents for Enhancing Business Education Curriculum for Skill Acquisition in Nigerian Universities

This study was on inculcating digital contents, technological tools as agents for enhancing business education curriculum for Skill Acquisition in Universities in Anambra State. Two research questions and null hypotheses were tested at a 0.05 level of significance. The study adopted a descriptive survey research design. A population of 34 business educators in Universities in Anambra state were used for the study. No sample was drawn for the study since the size of the population is manageable. The instrument used to collect data for the study was a structured questionnaire with two parts; part A contained items on the demography of respondents and part B contained items on the two research questions under the study.  The questions were structured on a 5 point rating scale of Strongly Agree (SA); Agree (A), Moderately Agree (MA), Disagree (D) and Strongly Disagree. The instrument was validated b three experts, two from the Department of Business Education and one from Measurement and Evaluation. Cronbach Alpha reliability coefficient was used to test consistency of the instrument and a general coefficient of 0.81.  Data collected was analyzed using arithmetic mean and standard deviation while t- test was used to test the hypotheses at 0.05 level of significance. When the p value was found to be equal or less than 0.05 alpha levels, the noted difference was said to be significant, therefore, the null hypothesis was be rejected. However, a p value found to be greater than 0.05, the noted difference was insignificant, therefore, the null hypothesis will be accepted. The findings of the study revealed that business education lecturers in universities in Anambra state agree that provision of instructional technology, inculcating digital contents can enhance business education curriculum for skill acquisition. These findings were discussed and conclusion was drawn. Relevant recommendations were made based on the findings of the study part of which included that Management of business education programme should incorporate digital tools and platforms that are relevant to various business disciplines, such as data analytics software, marketing automation platforms, project management tools, or simulation software. Provide hands-on training and practical exercises using these tools to develop students' proficiency in digital technologies applicable to the business contex

Energy Poverty and the Security Challenges in Northern Nigeria-Incidence and the Potential for Renewables

A Multidimensional Energy Poverty Index (MEPI) has been used to study the incidence of energy poverty in Nigeria. Secondary data from the United States Agency for International Development was collated from over 44,000 households, from which calculated MEPI for the various regions of Nigeria show that the southwest had the least incidence of energy poverty, while the northeast region had the highest energy poverty. Cogent connections have been made between recent security challenges in the northeast with energy poverty. Reports taken from studies and the mass media show that vast majority of attacks occur in the geopolitical region. Thus, renewables such as solar and wind energies abundant in northeast Nigeria have been identified as potential solutions to ending energy poverty and hence a strategic pathway to arresting the current security challenges

Gender variations in specialties among medical doctors working in public healthcare institutions in Bayelsa State, Nigeria

Background: Gender variations exist in the choice of specialties among doctors globally. This variation is of public health importance as it affects the distribution of doctors in public health institutions and patient care. In Bayelsa, Nigeria,no such study had been undertaken.This study aimed to examine gender variations in specialties among medical doctors working in public healthcare institutions in Bayelsa State.Methods: Cross-sectional study design was adopted for this study. Information about doctors working in public healthcare institutions in Bayelsa were collected via data extraction from the register of doctors at Niger Delta University Teaching Hospital (NDUTH) and at Hospital Management Board (HMB) of State Ministry of Health, and with self-completed questionnaires from doctors at Federal Medical Centre (FMC). In this paper, statistical analyses were restricted to data from FMC (n=91) and NDUTH (n=100) because they have multiple specialties. All available data were analyzed by gender and data analyses were carried out using SPSS statistical software.Results: Out of the191 doctors included in the analysis, 135(70.7%) were males. The median age was 32 years for male doctors and 29 years for female doctors.The top three specialty choices for males were obstetrics and gynaecology (14.8%),internal medicine (11.1%) and surgery (8.9%). For female doctors,pediatrics was the topmost specialty (25%) followed by obstetrics and gynaecology (10.7%) and internal medicine (8.9%). There were no female doctors in 14 specialties. Female doctors had higher proportions of house officers compared to males (45.5% versus 32.3% respectively). Conversely, male doctors had higher proportions of consultants/specialists than females (24.1% versus 9.1% respectively).Conclusion: Specialty distribution of doctors in Bayelsa is gendered and some specialties appear not to attract female doctors. These findings call for further studies to investigate the factors responsible for this gender variation, and to identify and address any barriers.Keywords: Gender variation,Specialties,Doctors,Public healthcare,Health workforc

Characteristics of medical doctors working in public healthcare institutions in a southern Nigerian state

Objective: This study assessed the characteristics of medical doctors working in public healthcare institutions and examined differences in some of the characteristics by geographical (urban versus rural) location.Methods: A cross-sectional study of doctors working in public healthcare institutions using data obtained from 3 centres in Bayelsa, Nigeria.Results: Three-quarters (75.4%) of the 280 medical doctors were males. Most of the doctors (68.6%) were working at tertiary healthcare level, 16.1% at primary and 15.4% at secondary healthcare levels. In terms of their professional positions, there were more medical officers (34.5%) relative to the other cadres while 17.2% were consultants. When their places of practice were dichotomised into rural and urban settings, 88.2% were practising in urban settings. A higher proportion of the 69 female doctors were practising in urban settings compared to rural settings (26.7% versus 9.1% respectively, P=0.027). There was a statistically significant relationship between residency status and place of practice (P=0.001). Specialists  (i.e. doctors who have completed residency training) were more likely to practice in urban (19.2%) than in rural settings (3.3%).Conclusion: Only a quarter of doctors in this study were females. There seemed to be more doctors at tertiary level of care and in urban areas. These findings suggest that there may be a shortage of female doctors, and that there may be unmet personnel needs at primary and secondary healthcare levels and in rural areas.Keywords: Health services, Human resources for heath, Health workforce, Geographical Distribution, Medical Doctor