Eskom-ZESA interconnected power system modelling

A research report submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree of Master of Science in Engineering, 2016The power system frequency must be kept as close as possible to the nominal value. This is due to the inherent design of electrical equipment to operate efficiently at the nominal frequency. Frequency regulation in an interconnected power system is the duty of all members of the interconnection. However, in the Eskom-ZESA interconnected power system Eskom engineers ignore the contribution of the ZESA system to primary frequency control. This is mainly due to the prevalent assumption that the ZESA control area is small relative to the Eskom control area and its contribution to primary frequency control of the interconnected power system is negligible. This document presents a project that examines the validity of this assumption via determination of the contribution of the ZESA system to the interconnected power system’s primary frequency control. The interconnected power systems background was studied to understand the theory behind the operation of two or more interconnected power systems. System frequency disturbances deemed to be a good representation of the Eskom-ZESA interconnected power system’s performance were selected and analysed to validate the current assumption. The results show that there is a significant support from ZESA during a system frequency disturbance. This proves that the existing assumption is not valid anymore. Furthermore; the generator model that mimics the Eskom-ZESA tie-line governing behaviour was developed. Two different types of governor models were employed; firstly the IEEEG1 governor was tuned to control generator output to match the tie-line performance and then the TGOV5 governor model was used. The IEEEG1 governor model is a simplified governor representation; as a result, it is not easy to tune the parameters to match tie-line response. However, the performance is acceptable and it can be used to represent the tieline governor response. The TGOV5 governor model is very complex as discussed in section 4.2. The model includes boiler dynamics, and this improves performance such that it is possible to tune the parameters to follow the tie-line performance as close as necessary.GR201

Food consumption patterns, socio- demographic status and nutritional risks of women in low and middle income communities in Kwandengezi, KwaZulu-Natal, South Africa

Food consumption patterns have changed dramatically in recent times. Traditional diets are replaced by “westernised diets” causing nutritional risks like malnutrition. Unemployment and lack of nutrition education have an impact on communities, in terms of the foods being purchased and consumed. This research seeks to establish a true reflection of the nutritional status, food intake patterns of the communities participating in the study and influencing factors. This is to estimate if the low income community, the north section is in a more disadvantaged situation when compared to the middle income community, the south section. The objective was to determine the socio-demographic status, food consumption patterns and nutritional risk of a lowincome and middle-income community that reside in KwaNdengezi Township in KwaZulu-Natal, South Africa.The research being undertaken consists of descriptive and theoretical studies. Upon consention, participants data were collected by means of an interview setting. A set of questionnaires included, Socio-demographic, Food Frequency and 24-Hour Recall questions. The anthropometric measurements were taken in order to determine the body mass index status. Both sections of the township were affected by unemployment. The education status of the participants showed concern as both sections had fewer graduates. The mean Food Variety Scores (FVS) (±SD) for all items consumed from various food groups during seven days, indicated a medium where both sections had a good dietary diversity score ranging from 7-9 food groups, which summarize the food group diversity as being in the majority in the north section. The results of energy distribution of macronutrients from the average of the 24-hr recall when compared to the WHO dietary factor goals showed that the participants’ diet was well balanced, in relation to macronutrient intake for both sections but was lacking in micronutrient intake. Overweight and obesity tests showed disturbing results with majority of women caregivers in both sections found to be obese, showing risks of obesity related illnesses (NCDs). More nutrition knowledge should be geared towards educating the most vulnerable and poverty stricken communities. The micronutrient intake must be promoted at lower and middle income communities.. The government should devise and implement projects that empower women so that they are not codependent.&nbsp

Evaluating Implementation of revised (post 2010) World Health Organisation Guidelines on Prevention of Mother to Child Transmission of HIV using Routinely Collected Data in Zambia.

The Joint United Nations Program on HIV/AIDS (UNAIDS) over the past two decades has documented the heavy burden and impact of HIV on mothers and infants living in resource-limited settings. The sub-Saharan Africa (SSA) region still faces a challenge of significant numbers of pregnant women who acquire HIV infection during pregnancy or postpartum but who are not diagnosed and offered antiretroviral medicines. The achievement of the UNAIDS goal relies on a successful implementation of a set of prevention of mother-to-child transmission (PMTCT) of HIV interventions called the PMTCT cascade. The goal of elimination of new paediatric infections has not been met, so there is a need to investigate why some programs are not effective. Routinely collected clinic data can provide much needed information on the prevalence of HIV among pregnant women and the uptake of services for PMTCT of HIV. In Zambia there is a substantial amount of data that has been collected through the SmartCare electronic health record system over the years, but the database has never been used to analyse the implementation of PMTCT programs. A mixed method study design was used which included a systematic review of literature, quantitative and qualitative methods. A systematic review of literature was conducted to identify, evaluate and summarise the findings from analysis of quantitative retrospective and prospective cohort studies that utilised routinely collected data with a focus on provision and utilisation of post 2010 PMTCT services in SSA. The quantitative analysis of SmartCare routinely collected data provided an overview of PMTCT coverage and the performance of early infant diagnosis (EID) services. Qualitative data was collected using in-depth interviews, observations and focus groups discussions (FGD) to understand the implementation procedures of SmartCare. The findings from the systematic review of literature showed a decrease in the mother to child transmission (MTCT) rate but poor quality routinely collected data. The quantitative analysis of 104, 155 pregnant women seeking antenatal care (ANC) services in 886 health facilities indicated an increase from 2010 to 2015 in the proportion of HIV- infected women who were already on treatment. The analysis of data comprising 32, 593 HIV-infected infants born in the pre (2006-2009) and post (2010-2016) Option B+ periods revealed that there has been progress in the EID program implementation. The results from the two quantitative studies were characterised by missing data which introduced bias and affected the external validity of the findings. The findings from SmartCare data analysis were triangulated with the Health Management Information System (HMIS), which further confirmed the conclusion drawn. The SmartCare database has structural challenges which can be traced to its development and in addition it has faced a lot of implementation challenges which include funding gaps, lack of feedback from the system and the absence of uniform data collection and verification procedures. The thesis is the first study to have attempted to evaluate the implementation of PMTCT guidelines using routinely collected data from the SmartCare electronic health record (EHR) system database. Recommendations arising from the thesis include upgrading of SmartCare into a networked Open Medical Record System. The Zambia MoH with its partners could also implement a SmartCare performance-based financing initiative in order to improve the implementation of EHR system. Further studies are needed to investigate the impact of implementing PMTCT guidelines particularly on the retention in care and adherence to treatment and EID

Descriptive analysis of World Health Organization-recommended second-line antiretroviral treatment: A retrospective cohort data analysis

Background. World Health Organization guidelines recommend that HIV patients who do not achieve viral suppression on efavirenz-based first-line antiretroviral therapy (ART) should be changed to a protease inhibitor (PI)-based regimen. In South Africa (SA), ~200 000 people are on second-line treatment, but little is known about these patients.Objectives. To describe second-line black African patients in a large urban area.Methods. A quantitative retrospective study of 825 second-line patients in central Johannesburg, SA (subdistrict F), was performed with data extracted from government databases. Demographic characteristics, treatment status and laboratory information were gathered, then analysed with CD4+ cell count, viral load (VL) and retention-in-care data as outcome variables.Results. The average recorded time to VL measurement after the switch to a PI-based ART regimen was 20 months, and 83.1% (570/686) of patients with a recent VL achieved viral suppression while on second-line treatment. The most recent median CD4+ cell count for the cohort was 286 cells/µL (interquartile range 160 - 478), which represented a 177 cells/µL increase from the baseline count at the start of first-line ART. Slightly less than three-quarters (72.4%) of the population remained active in care in the study clinics from initiation on first-line ART. Demographic characteristics such as being <25 years of age, male sex and geographical transfer (started initial treatment in a different region) independently predicted low CD4+ cell counts and virological failure on second-line treatment. Patients with virological failure were most likely (odds ratio (OR) 3.13, 95% confidence interval (CI) 1.50 - 6.56) to be lost to follow-up after the switch, while patients from Hillbrow Community Health Centre (OR 0.27, 95% CI 0.16 - 0.44), South Rand Hospital (OR 0.24, 95% CI 0.12 - 0.47) and Jeppe Clinic (OR 0.38, 95% CI 0.16 - 0.88), three larger sites, were most likely to remain active in care.Conclusions. VL suppression was high in patients on second-line treatment, but one-fifth of patients were lost to follow-up. Younger age, male sex and transfer from other treatment sites predicted poor treatment outcomes, highlighting opportunities for prioritisation of adherence interventions.

Isothermal Crystallization Kinetics and Morphology of Double Crystalline PCL/PBS Blends Mixed with a Polycarbonate/MWCNTs Masterbatch

In this work, the 70/30 and 30/70 w/w polycaprolactone (PCL)/polybutylene succinate (PBS) blends and their corresponding PCL/PBS/(polycarbonate (PC)/multiwalled carbon nanotubes (MWCNTs) masterbatch) nanocomposites were prepared in a twin-screw extruder. The nanocomposites contained 1.0 and 4.0 wt% MWCNTs. The blends showed a sea-island morphology typical of immiscible blends. For the nanocomposites, three phases were formed: (i) The matrix (either PCL- or PBS-rich phase depending on the composition), (ii) dispersed polymer droplets of small size (either PCL- or PBS-rich phase depending on the composition), and (iii) dispersed aggregates of tens of micron sizes identified as PC/MWCNTs masterbatch. Atomic force microscopy (AFM) results showed that although most MWCNTs were located in the PC dispersed phase, some of them migrated to the polymer matrix. This is due to the partial miscibility and intimate contact at the interfaces between blend components. Non-isothermal differential scanning calorimetry (DSC) scans for the PCL/PBS blends showed an increase in the crystallization temperature (Tc) of the PCL-rich phase indicating a nucleation effect caused by the PBS-rich phase. For the nanocomposites, there was a decrease in Tc values. This was attributed to a competition between two effects: (1) The partial miscibility of the PC-rich and the PCL-rich and PBS-rich phases, and (2) the nucleation effect of the MWCNTs. The decrease in Tc values indicated that miscibility was the dominating effect. Isothermal crystallization results showed that the nanocomposites crystallized slower than the neat blends and the homopolymers. The introduction of the masterbatch generally increased the thermal conductivity of the blend nanocomposites and affected the mechanical properties.Thandi P. Gumede was financially supported by the National Research Foundation and the Sasol Inzalo Foundation in South Africa, while the POLYMAT/UPV/EHU team was funded by the following projects: “UPV/EHU Infrastructure: INF 14/38”; “Mineco/FEDER: SINF 130I001726XV1/Ref: UNPV13–4E–1726” and MINECO MAT2017-83014-C2-1-P. The publication of this article was funded by the Qatar National Library

Malaria control – two years' use of insecticide treated bednets compared with insecticide house spraying in Kwazulu-Natal

Objectives_ The objective of this study was to produce data indicating whether insecticide-treated bednets should replac insecticide house spraying as a malaria control method in South Africa_ We report 2 years of preliminary data on malaria incidence comparing areas receiving insecticidetreated bednets and those subjected to house spraying in northern KwaZulu-Natal.Design, setting and subjects. In order to measure significant reductions in malaria incidence between the two interventions, a geographical information system (GIS) was used to identify and create seven pairs of geographical blood ; (areas) in the malaria high-risk areas of Ndumu and Makani in Ingwavuma magisterial district, KwaZulu-Natal, Individual blocks were then randomly allocated to either insecticide-treated bednets or house spraying with deltamethrin. Malaria cases were either routinely recorded by surveillance agents at home or were reported to the nearest health facility_Results and conclusions. The results show that 2 years' use of insecticide-treated bednets by communities in Ndumu and Makanis, KwaZulu-Natal, significantly reduced the malaria incidence both in 1997 (rate ratio (RR) =0_879, 95% confidence interval (Cn 0.80 - 0.95, P =0.04) and in 1998 (RR = 0.667, Cl 0_61 - 0.72, P = 0.0001). Using a t-test, these significant reductions were further confirmed by an assessment of the rate of change between 1996 and 1998, showing a 16% reduction in malaria incidence in blocks using bednets and an increase of 45% in sprayed areas (t = 2.534, P = 0.026 (12 df». In order to decide whether bednets : should replace house spraying in South Africa, we need more : data on the efficacy of treated bednets, their long-term acceptability and the cost of the two interventions

Isothermal Crystallization Kinetics and Morphology of Double Crystalline PCL/PBS Blends Mixed with a Polycarbonate/MWCNTs Masterbatch

Published ArticleIn this work, the 70/30 and 30/70 w/w polycaprolactone (PCL)/polybutylene succinate (PBS) blends and their corresponding PCL/PBS/(polycarbonate (PC)/multiwalled carbon nanotubes (MWCNTs) masterbatch) nanocomposites were prepared in a twin-screw extruder. The nanocomposites contained 1.0 and 4.0 wt% MWCNTs. The blends showed a sea-island morphology typical of immiscible blends. For the nanocomposites, three phases were formed: (i) The matrix (either PCL- or PBS-rich phase depending on the composition), (ii) dispersed polymer droplets of small size (either PCL- or PBS-rich phase depending on the composition), and (iii) dispersed aggregates of tens of micron sizes identified as PC/MWCNTs masterbatch. Atomic force microscopy (AFM) results showed that although most MWCNTs were located in the PC dispersed phase, some of them migrated to the polymer matrix. This is due to the partial miscibility and intimate contact at the interfaces between blend components. Non-isothermal di erential scanning calorimetry (DSC) scans for the PCL/PBS blends showed an increase in the crystallization temperature (Tc) of the PCL-rich phase indicating a nucleation e ect caused by the PBS-rich phase. For the nanocomposites, there was a decrease in Tc values. This was attributed to a competition between two e ects: (1) The partial miscibility of the PC-rich and the PCL-rich and PBS-rich phases, and (2) the nucleation e ect of the MWCNTs. The decrease in Tc values indicated that miscibility was the dominating e ect. Isothermal crystallization results showed that the nanocomposites crystallized slower than the neat blends and the homopolymers. The introduction of the masterbatch generally increased the thermal conductivity of the blend nanocomposites and a ected the mechanical properties

Nigeria’s fiscal health: an analysis of budget process, systems and trends [2014 – 2016]

Nigeria is an oil dependent economy which faced a lot of economic and political challenges between the periods under review, such as increased broad money supply, fall in the value of money market assets, decline in the unpaid FGN Bonds, unfavorable exchange rates, fall in oil prices, and the May 2015 general elections, amongst others. Nigeria’s fiscal stance was thus threatened, and it is in light of these that the paper, uses interactions between expenditure, revenue, debts, and deficits trends, to compute indices that capture its fiscal health. The study found that using compounded annual growth rates (CAGR), certain sectors with high CAGRs (Interior, Transport, Finance, Science & Technology, and Health) seemed to be prone to high fiscal mismanagement. Also, conservativeness in applying debt instruments are unavailable, and such measures are not tied to growth; revenue from increased taxation are not matched with requisite infrastructure; and debts are not adequately tied to capital projects, as established in Fiscal Responsibility Act. Amidst several, few recommendations are undoubtedly notable mainly; that overhead costs revealed in several line-items and are marked up should be eradicated; and huge recurrent expenditure, mainly personnel cost (about 75% of the total budget) mostly visible as remuneration “in kind” should be strictly removed from the line items and programmes at MDA level. Thus, Nigeria’s government should maintain expenditure ceilings; create solidified link between policy and budget; establish realistic fiscal targets and indicators; and allow more public participation in budget process

Poverty and 'Second Economy' in South Africa: An Attempt to Clarify Applicable Concepts and Quantify Extent of Relevant Challenges

In brief, the paper firstly summarises old and new theoretical and technical issues on measuring poverty, secondly analyses poverty from different perspectives and highlights various research findings on poverty trends in South Africa and thirdly clarifies the notion of "second economy" and attempts to "measure" it

Exploring adolescents and young people's candidacy for utilising health services in a rural district, South Africa.

BACKGROUND: We use the 'candidacy framework' to describe adolescents' and young people's (AYP) experiences of health services in a rural KwaZulu-Natal district, South Africa. METHODS: A qualitative approach was used including group discussions, in-depth and key informant interviews with a purposive sample of AYP (n = 70), community leaders (n = 15), school health teams (n = 10), and health service providers (n = 6). RESULTS: Findings indicate tacit understanding among AYP that they are candidates for general health services. However, HIV stigma, apprehensions and misconceptions about sexual and reproductive health, and socio-cultural views which disapprove of AYP pre-marital sex undermine their candidacy for sexual and reproductive services. CONCLUSION: Consideration and understanding of the vulnerabilities and reasons AYP exclude themselves will inform interventions to address their health needs. AYP's participation in the design of health services will increase their acceptability and encourage uptake of services