Influence of hydrodynamics on carbon steel erosion-corrosion and inhibitor efficiency in simulated oilfield brines

Corrosion within the oil and gas sector is an ongoing concern for operators. The challenging nature of extraction and processing fluids is an unavoidable cause of severe metallic corrosion. With modern emphasis on health, safety and the environment, the case for managing corrosion has become an imperative agenda. Whilst new and more effective methods of mitigation are key, an interim solution is improving the value of current methods. A literature survey carried out within this project has revealed CO2 corrosion as contributing to most corrosion related failures within the industry. The corrosion behaviour in CO2 containing environments is complex partly due to the wide range of prevailing conditions such as temperature, CO2 concentration and flow conditions. For oil and gas transportation pipelines, internal corrosion mitigation can be achieved by the use of chemical inhibitors. Inhibitors have been established to be effective but are by no means a complete solution. Issues such as their effectiveness in high velocity and high shear flow are a main consideration for their function. The hydrodynamic nature of the flowing fluids can affect inhibitor efficiency by either slowing the rate of formation of the inhibitive layer or causing degradation of well-formed inhibitive layers. A combined effect may also be active. The corrosion behaviour of carbon steel in simulated oilfield conditions is investigated in this project with emphasis on conditions of varying velocity, impinging flow and consequently shear stress. Since inhibition is the main mitigation technique for fluid related corrosion, the efficiency of a commercially used inhibitor is, in this case assessed in the abovementioned conditions. To simulate both impingement and flow, a jet impingement apparatus is used in conjunction with a segmented-electrode specimen set up to separately study the erosion-corrosion behaviour of different hydrodynamic zones under the jet. Corrosion rates are measured by gravimetric analysis and results are also evaluated with electrochemistry. Additionally, galvanic interactions between the different hydrodynamic zones have been investigated. Visual and light-optical microscopic examinations are also used to assess variable effects within the zones. Under such conditions, the corrosion rates have been found to be significantly higher in impingement zones. Aerated conditions have shown a significant variation in corrosion behaviour between impingement and non-impingement zones. The results in CO2 saturated brines are consistent but with evidence of different relations between hydrodynamics and the corrosion rate. The inhibitor has been shown to be effective in CO2 saturated brines and significantly influenced by both inhibitor concentration and hydrodynamic conditions. Inhibitor efficiency has also shown a complex dependence on concentration and establishes a need to evaluate optimum inhibitor concentrations before field application. Evaluation of the mass loss results against electrochemistry has shown a large discrepancy between the two methods. This rather surprising result suggests solid-free flow is not entirely free of erosion and synergistic effects. This comprehensive study has not only improved current knowledge on the relation between hydrodynamics and inhibitor efficiency but also indicates a critical need to evaluate suitability of current monitoring methods. Electrochemical methods are increasingly used as a method of choice and while they contribute significant monitoring data, they are observed to be unable, alone, to monitor erosion and synergy. An industry review on their suitability to monitor solid-free flow corrosion is recommended

Hydatidiform mole

A CAJM article on recent clinical research findings pertaining to the Hydatidiform mole.This article critically reviews the current understanding of the origin of hydatidiform mole. The pathogenesis, clinical presentation and diagnosis is discussed. Suction curettage and close patient follow up reduces the mortality and morbidity of the patients with this disease

Strategic Church Planting in the Central Zimbabwe Conference: Towards a Paradigm Shift in Church Growth

Problem This dissertation focuses on church planting in the Central Zimbabwe Conference. While impressive results have been achieved in evangelizing the lower classes of the society, there has been meager success in reaching the upper classes of the Black community as well as the White, the Indian, and the Colored minorities. A strategic church-planting approach to church growth hopes to not only target the least promising population segments served by the Central Zimbabwe Conference, but also to increase the effectiveness of the other church methods currently being employed to reach the more responsive classes in that conference. Method A diachronic analysis of the various church-growth methods that have been and are currently being used in the Central Zimbabwe Conference is conducted, highlighting their strengths and weaknesses. Data gathered from interviews and a survey sent to the Central Zimbabwe Conference authenticate the need for a paradigm shift in church growth that is driven by a church-planting consciousness. Conclusion The Central Zimbabwe Conference has much to gain by embracing a strategic church-planting approach to church growth. Placing church planting at the core of the conference\u27s mission enhances lay participation in evangelism and is cost effective

Perceptions of Board Effectiveness in Selected Institutions of Higher Education in Zimbabwe

Problem The purpose of this study was to identify the level of board effectiveness in selected private and public universities in Zimbabwe as perceived by board members. Also, the study sought to determine the influence of such demographic variables as age, education level, and years of service on the seven factors of university functioning: institutional mission, institutional planning, physical plant, financial management, board membership, board organization and performance, and board/vice chancellor relations. Method The survey method was used to collect data. Respondents were asked to complete a 47-item questionnaire and indicate their level of agreement on each of the questions (3 = yes, 2 = uncertain, and 1 = no). The sample for the study was made up of 29 university council members from each of the three selected universities giving a total of 87. Out of 87 survey forms mailed, a total of 55 respondents returned usable survey forms. The data were analyzed using mean scores and one-way analysis of variance (ANOVA). Results The respondents at University Council A perceived the board to be effective in four of the seven areas of university functioning. There were significant differences in perception on institutional planning based on education level (p = .000). Board members with bachelor’s and master’s degrees revealed that they were better at institutional planning than those with a doctorate. Respondents at University Council B perceived the board to be effective in six of the seven areas of university functioning. Significant differences in perception on institutional planning based on education level were noted (p = .016). Those with a doctorate regarded institutional planning more highly than board members with master’s degrees. Finally, respondents from University Council C perceived the board to be effective in six out of seven areas of university functioning. Differences in perception occurred on institutional mission based on age differences (p = .001), board membership based on age (p - .010), board organization and performance based on age (p = .007), and board organization and performance based on education level {p = .034). Newman- Keuls post hoc tests revealed that older members regarded institutional mission, board membership, and board organization and performance more highly than the younger members. Further, at University C, data reveal that those with doctorate degrees tended to be more organized and to perform better on board matters than those with master’s degrees. Conclusions There is a great deal of consensus in perception among university council members at the three selected universities in Zimbabwe regarding their effectiveness in accomplishing the seven areas of university functioning. However, all three university councils need to emphasize diversity in regard to board composition to include gender in the selection process. Universities in the study should develop an orientation and continuing education program in order to gain an in-depth knowledge of the institutions they serve. Fund-raising for the institutions should not be left to the CEO alone, but should also be the duty of every board member

Teachers’ experiences of the principal’s instructional leadership styles in primary schools in Gauteng Province

This study explores teachers’ experiences with the principals’ instructional leadership styles in primary schools in Gauteng province. A qualitative research design was employed in the study to answer the research question. Data was generated by means of semi structured interviews which involved the three HODs and nine ordinary teachers from the three sampled schools so as to provide a rich description, explanation, experiences, challenges and barriers that instructional leadership brings into the teaching and learning process in their particular schools contexts. The interest in the phenomenon emerged on the perspective of principals’ instructional leadership as often seen as the contributor to the challenges that are experienced by Primary school teachers during the learning process. Principals are viewed as contributing to South Africa’s education crisis and the overall ineffectiveness of the school system resulting in poor academic results. The instructional leaders who are not doing their jobs competently because of their leadership styles and lack of supervision skills, have caused this. This includes proper knowledge of how to run the schools and motivating staff to work, to enhance classroom instruction. Sometimes they do not involve the community and other stakeholders in the decision making process. Teachers who provide moral support and professional growth in the schools are also ignored.Educational Leadership and ManagementM. Ed. (Education Management

A strategy to facilitate transition from masters degree nursing studies to PhD/doctoral thesis proposal writing

Background: Challenges in thesis proposal writing have resulted in doctoral students dropping from research studies resulting in the shortage of doctoral prepared nurses. Impediments include lack of human and non-human resources. Benner’s theory of novice to expert formed the basis for the development of the strategic intervention and action plan to address the challenges and strengths experienced by master’s prepared doctoral students during thesis proposal writing Purpose: The purpose of this research was to develop a strategic intervention and action plan that can be used to assist doctoral students to succeed in thesis proposal writing. Methods: An exploratory mixed-methods approach combining qualitative and quantitative data collection and analysis in four phases was used. In Phase 1 qualitative data from two open-ended questions were used to gather data, combined with literature to develop a questionnaire for Phase 2. A questionnaire was developed from data obtained from Phase 2 as well as a thorough literature review to develop the strategic intervention and Action plan. In Phase 4 the strategic intervention and action plan was validated using the Delphi technique and experts acted as panellists for the validation. Framework: Benner’s novice to expert theoretical framework was adopted for the study because of the assumption that doctoral students need a change of perception and assistance in order to develop critical thinking skills that will enhance the development of research competencies. This framework was used because of its relevance to the study. Research Findings: Competence in doctoral thesis proposal writing is affected by human resources as well as non-human resources. The identified strategic interventions that were included in the action plan were: recruitment of competent supervisors, training and mentoring of new supervisors, achieving of a realistic student/supervisor ratio for supervision of students, timely allocation of supervisors, recruiting of subject librarians and employment of adequate library support, provision of peer support programmes, implementation of a student recruitment and selection plan, provision of student support programmes to enhance research skills and competencies, binding contracts to stipulate students responsibility, provision of adequate research resources, and implementation of a bursary system among others. Conclusion: The strategic intervention and action plan was developed using the input of doctoral nursing students who were in the process of completing their thesis proposal and a thorough literature review. The inclusion of the deans of nursing of universities and universities of technology of South Africa (FUNDISA) will enhance the possibility for the implementation of the strategic intervention and action plan which can contribute to assisting the master’s prepared doctoral students to successfully transition from novice students with little or no research knowledge to competent thesis proposal writers.Health StudiesD. Litt. et Phil. (Health Studies

The concept of sin in the theologies of Ellen G White and Leonardo Boff : a comparative study

The aim of this thesis is to compare the concept of sin in the theologies of Ellen G. White and Leonardo Boff. Chapter 1 examines Ellen G. White's concept of sin. White's historical and theological backgrounds coupled with her use of the "great controversy" motif provide a better grasp of her understanding of sin. White defines sin as the transgression of God's Law. She views sin to comprise at least two dimensions, namely, the individual and the social. White regards these two aspects of sin to have equal significance. White's detailed treatment of the sanctuary teaching also highlights the two dimensions of sin. In Chapter 2 Boff' s idea of sin is investigated. Boff' s historical background, which exposed him to the poor, influenced his perception of sin. Boff's theological background together with his familiarity with Karl Marx's social analysis prompted Boff to define sin as the negation of God's love in a human history bedevilled by class conflict. Boff views sin to have the individual and social dimensions. Yet, in terms of importance, Boff believes that the social dimension of sin is more consequential than the individual one. In Chapter 3 White's and Boff s views on sin are compared. From this comparison it is evident that both White and Boff recognize the bipolarity of sin. Both seem to agree that christians should take an active role in correcting social evils because love for God is manifested by how we relate to our neighbor. Boff devotes less space to the individual aspect of sin than White. Chapter 4 shows that White's theological tradition has a lot to learn from Boff and his tradition and also vice versa. An awareness of the current priestly ministry of Christ evident in White's theology could help Boff to bring some balance to his stance on the social and the individual dimension of sin. Boff' s use of Marx's social analysis should also help Seventh-day Adventists, the inheritors of White's theology, not to interpret White's theology of sin only along individualistic lines while overlooking its social dimension.Philosophy, Practical and Systematic TheologyD.Th. (Systematic Theology

Ellen G. White and Gustavo Gutierrez on christians and involvement in politics : a comparative study

Ellen G. White and Gustavo Gutierrez make significant contributions on the issue of christians and involvement in politics. A knowledge of their backgrounds and theological orientations is helpful. White was born in 1827. She is accepted as a prophet in the Seventh-day Adventist church. Central to her theology is the sanctuary doctrine which also influences her views on politics. White holds that christians may participate in the "broad" but not the "narrow" aspect of politics. A Roman Catholic priest, Gutierrez was born in 1928. Many regard him as the pioneer of liberation theology. The starting point for his theology is the situation of poverty in Latin America. This influences his views on politics. He also argues for christians' participation in the "broad" but not the "narrow" aspect of politics. White and Gutierrez have more points of agreement than disagreement. Comparing their views on politics provides useful insights on christians' participation in politics. "I declare that: ELLEN G. WHITE AND GUSTAVO GUTIERREZ ON CHRISTIANS AND INVOLVEMENT IN POLITICS: A COMPARATIVE STUDY is my own work and that all the sources that I have used or quoted have been indicated and acknowledged complete references'Philosophy, Practical and Systematic TheologyM.Th. (Systematic Theology

Induction of labour with titrated oral Misoprostol suspension: a comparative study with vaginal Misoprostol

A CAJM journal article comparing the effectiveness of titrated orally and vaginally administered misoprostol for induction of labour administered at the University of Zimbabwe Teaching Hospital..Objective: To compare the effectiveness of titrated orally and vaginally administered misoprostol for induction of labour. Study Design: Unmasked randomized controlled trial. Setting: Department of Obstetrics and Gynaecology University of Zimbabwe, Harare. Subjects: Pregnant women with singleton foetus in cephalic presentation booked for induction of labour, were randomized to receive titrated orally or vaginally administered misoprostol. Main Outcome Measures: The main outcomes were the duration of labour and induction to delivery interval. The secondary outcomes were neonatal and maternal complications. Methods: 134 women were recruited into the study; 69 and 65 were randomized into orally and vaginally administered misoprostol respectively. Results: The baseline characteristics in the two groups were similar. Women induced with titrated oral misoprostol suspension had a shorter interval from administration of the drug to initiation of uterine contractions (OR = 0.94 .95% Cl 0.42 to 2.12 ) and a longer duration of labour (OR = 0.36; 95% Cl 0.16 to 0.79). Labour was augmented with oxytocin in the oral group. The mean drug dose was 28mcg in the oral group. There was no difference in the mode of delivery between the two groups. Hypertonic uterine contractions were not detected. Ruptured uterus did not occur in the study population. There were more neonatal admissions in the vaginal than the oral group (OR = 1.03 .95% Cl 0.29 to 1.39). Conclusion: Titrated oral misoprostol suspension is as effective and safe as vaginal misoprostol for induction of labour even in poor resource countries where intrapartum monitoring is inadequate

Lipid-soluble Vitamins A, D, and E in HIV-Infected Pregnant women in Tanzania.

There is limited published research examining lipid-soluble vitamins in human immunodeficiency virus (HIV)-infected pregnant women, particularly in resource-limited settings. This is an observational analysis of 1078 HIV-infected pregnant women enrolled in a trial of vitamin supplementation in Tanzania. Baseline data on sociodemographic and anthropometric characteristics, clinical signs and symptoms, and laboratory parameters were used to identify correlates of low plasma vitamin A (<0.7 micromol/l), vitamin D (<80 nmol/l) and vitamin E (<9.7 micromol/l) status. Binomial regression was used to estimate risk ratios and 95% confidence intervals. Approximately 35, 39 and 51% of the women had low levels of vitamins A, D and E, respectively. Severe anemia (hemoglobin <85 g/l; P<0.01), plasma vitamin E (P=0.02), selenium (P=0.01) and vitamin D (P=0.02) concentrations were significant correlates of low vitamin A status in multivariate models. Erythrocyte Sedimentation Rate (ESR) was independently related to low vitamin A status in a nonlinear manner (P=0.01). The correlates of low vitamin D status were CD8 cell count (P=0.01), high ESR (ESR >81 mm/h; P<0.01), gestational age at enrollment (nonlinear; P=0.03) and plasma vitamins A (P=0.02) and E (P=0.01). For low vitamin E status, the correlates were money spent on food per household per day (P<0.01), plasma vitamin A concentration (nonlinear; P<0.01) and a gestational age <16 weeks at enrollment (P<0.01). Low concentrations of lipid-soluble vitamins are widely prevalent among HIV-infected women in Tanzania and are correlated with other nutritional insufficiencies. Identifying HIV-infected persons at greater risk of poor nutritional status and infections may help inform design and implementation of appropriate interventions