2694 research outputs found
Sort by
Synthesis of Acid Leached Diatomaceous Earth/ Amine-Functionalized Activated Carbon Composite and its Potential Application in Oily Wastewater Treatment
No full textMENVSCDepartment of Geography and Environmental SciencesDue to the expanding worldwide oil exploration, a significant amount of oily wastewater is being produced. Oily wastewater lowers the diversity of aquatic life and plants by changing the structure of aquatic communities and food chains, among other ecological disturbances. Therefore, the overall aim of this project is to synthesize acid-leached diatomaceous earth (DE) and amine-functionalized activated carbon composite adsorbent for the treatment of oily wastewater. Acid leached diatomaceous earth was synthesized by leaching the raw diatomaceous step-wisely in a 120 mL volume of 2.2 M Nitric acid (HNO3) for three hours on a hotplate set to 60°C at a speed of 300 rpm. Thereafter, the mixture was filtered and the residue was washed with 1.5 L of deionized water. The residue was oven-dried at 50°C for 12 hours. The acid leached DE was then ground with mortar and pestle and then kept in a zip lock bag for further use in oily wastewater treatment. Activated carbon was synthesized from raw macadamia nutshell using of Orthophosphoric acid (H3PO4). Response surface methodology was used to determine the optimum conditions for synthesizing activated where 3 parameters (activation time, impregnation ratio, and activation temperature) were varied. Furthermore, 13 runs were completed at diverse conditions from the response surface methodology. To modify the synthesized activated carbon, hydroxylamine hydrochloride was used as a chemical agent to enhance the adsorption efficiency on the surface of the activated carbon and the amine-functionalized activated carbon was used in the removal of oil from oily wastewater. Lastly, a composite was prepared using both the synthesized acid leached diatomaceous earth and amine functionalized activated carbon and further evaluate its adsorption capacity and oil removal efficiency. All the synthesized adsorbents were applied in oily wastewater treatment and response surface methodology was used to optimize the variable parameters (adsorbent dosage, initial oil concentration and contact time) and to determine the optimum conditions for the oil removal efficiency. Therefore, this study was divided into 3 sections of results as discussed below.
The first section of results is focused on the preparation of acid leached diatomaceous earth and its application in oily wastewater treatment. The results showed that acid treatment does not alter the physical structure of the diatomaceous earth significantly although there was an increase of silica content, its surface area, and pore volume from 78.98 to 91.57%, 15.02 to 22.40 m2/g, and 60.88 to 68.71 Å, respectively. The maximum adsorption capacity of 124.16 mg/g and oil removal efficiency of 78.55% were achieved at initial oil concentration of 3229.69 using 0.05 g adsorbent dosage and 119.20 mins contact time. The adsorption kinetics data fitted
better to pseudo-second order model (R2=0.98) of reaction kinetics indicating that adsorption occurred through chemisorption. The adsorption isotherms were descried better by the Freundlich isotherms model (R2=0.87) indicating that adsorption occurred in a heterogeneous and multilayer surface.
The second section focused on the synthesis of amine functionalized activated carbon for oily wastewater treatment. Activated carbon was prepared from macadamia nutshells (MNS) using H3PO4 as activating agent and further modified with amine groups using hydroxylamine hydrochloride. Amine-functionalization increases the adsorption capacity and removal efficiency due to expansion of the adsorbent’s particles. The oil removal experiment using amine-functionalized activated carbon showed a maximum percentage removal of 82.93% with adsorption capacity of 167.96 mg/g when initial oil concentration of 10 000 mg/L, adsorbent dosage of 0.1 g adsorbent dosage and contact time of 60 mins were used. The adsorption kinetics data fitted to pseudo-second order model (R2=0.92) of reaction kinetics indicating that adsorption occurred via chemisorption. The adsorption isotherm data fitted Freundlich adsorption isotherms (R2=1) model indicating that adsorption took place on heterogeneous and multilayer surface.
The last section of the study focused on the preparation of the acid leached diatomaceous earth/amine-functionalized activated carbon composite adsorbent and its application in treatment oily wastewater. Due to challenges associated with synthesizing an ideal adsorbent for oily wastewater treatment, this composite adsorbent was synthesized to overcome the activated carbon drawbacks which include low thermal conductivity affecting the regeneration efficiency leading to a reduced adsorption capacity after being used for a certain period. Consequently, the advantages of the diatomaceous earth which include excellent heat resistance and its high porosity can improve the physicochemical properties such as surface area and thermal conductivity on the composite adsorbent. The SEM micrographs showed the presence of pores and rough surface with some particles of varying sizes on the surface of the composite material due to the addition of some functional groups which allowed the transfer of the oil molecules into the inner surface of the composite adsorbent. The prepared composite adsorbent showed a maximum oil removal percentage of 90.02% with maximum adsorption capacity of 416.67 mg/g at initial oil concentration of 5250 mg/L, an adsorbent dosage of 0.3 g, and contact time of 60 mins. The adsorption kinetics data showed a better fit to the pseudo-second order model (R2=0.98) showing that adsorption took place via chemisorption.
Freundlich adsorption isotherm model descried the adsorption better showing that adsorption occurred on a heterogeneous and multilayer surface.
Based on these findings, both materials prepared in this study has potential for use in treatment of oily wastewater. However, the composite displayed higher affinity towards treatment of oily wastewater compared to the acid leached diatomaceous earth and amine-functionalized activated carbon. Based on the conclusions, the main recommendations made from this study were to: 1) test the feasibility of adsorbent in field application and 2) conduct the cost-benefit analysis for this adsorbent.National Research Foundation (NRF
The Right to Sustainable Development for Women in South Africa: A Critical Analysis of Article 19 of the Protocol to the African Charter on Human and Peoples’ Rights on the Rights of Women in Africa
No full textLLMDepartment of Public LawThe Protocol to the African Charter on Human and Peoples’ Rights on the Rights of Women in Africa (hereinafter referred to as the Maputo Protocol) highlights the importance of sustainable development for women in Article 19. This research delves into an analysis of this article. Section 9 of the Constitution ensures that everyone is treated equally under the law. This provision serves as a basis for supporters of women's rights to advocate for progress, in South Africa by focusing on initiatives that empower women. Various laws have been put in place to uphold this entitlement. The question remains; are they adequate, in addressing the challenges faced by women concerning equality and sustainable development? The focus of this study is to examine the existing framework aimed at promoting women’s rights to development. The doctrinal research approach is utilised in this study. The current legal framework concerning the right to sustainable development may not be comprehensive enough to tackle the obstacles encountered by women. The objective is to evaluate the legal framework surrounding this clause and provide recommendations based on research findings.National Research Foundation (NRF
Managing Teaching and Learning of Social Sciences by Departmental Heads in the General Education and Training (GET) Band in North-West Rural Primary Schools, Ganyesa Circuit
No full textM.Ed. (Educational Management)Department of Educational ManagementThe major purpose of this study was to investigate how to manage the teaching and learning of Social Sciences by Departmental Heads in the General Education and Training Band in North-West rural primary schools, Ganyesa Circuit. During the period 2004-2012 in the National Curriculum Statements (NCS), there were two separate subjects History and Geography however the new Curriculum and Assessment Policy Statement (CAPS), has combined those two subjects known as “Social Sciences”. This study examined the managing of teaching and learning of Social Sciences in the GET band. The assumptions of the study are the SMTs members face challenges in managing the teaching of Social Sciences in the GET band and SMTs lack knowledge and understanding of optimal management strategies/approaches on how Social Sciences should be taught in the GET band. Furthermore teachers are not well trained in the teaching of Social Sciences.
This study was qualitative, using a case study approach and purposive sampling was used to select participants for data collection. The sample comprised of 4 principals (2 males, 2 females), 4 departmental heads (DHs) (2 males, 2 females), 8 educators (4 males, 4 females) from the selected schools; in-depth interviews were used to gather data from the participants. A thematic approach guided by Tesch’s 8 steps model was employed to identify themes and sub-themes on management strategies for the subject.
It is believed that the results would assist in identifying the difficulties that school stakeholders are having in managing the teaching and learning of social sciences, which has prevented them from achieving favourable educational outcomes. The findings showed that the DHs are not giving full support to the educators which hampers learner’s performance, DHs and the educators are not qualified to teach Social Sciences which show that there is a problem with recruitment and subject allocation. Furthermore, most of the educators are not getting full support from their DHs due to them not having enough content knowledge therefore DHs need proper trainings to empower them. The researcher identified the management strategies for the teaching and learning of Social
Sciences which were subsequently utilized to develop a framework for efficiently and effectively managing Social Sciences, not only in the Ganyesa Circuit, but in other schools in South Africa. It is anticipated that the findings will be published in accredited journals and disseminated in the form of reports to all school stakeholders and the Provincial Department of Basic Education (PDBE).NR
Probabilistic renewable energy modelling in South Africa
No full textPhD (Statistics)Department of Mathematical and Computational SciencesThe variability of solar power creates problems in planning and managing
power system operations. It is critical to forecast accurately in order to maintain
the safety and stability of large-scale integration of solar power into the
grid. Accurate forecasting is vital because it prevents transmission obstruction
and maintains a power equilibrium. This thesis uses robust models to
solve this problem by addressing four main issues. The first issue involves
the construction of quantile regression models for forecasting extreme peak
electricity demand and determining the optimal number of units to commit
at minimal costs for each period using the forecasts obtained from the developed
models. The bounded variable mixed-integer linear programming
(MILP) model solves the unit commitment (UC) problem. This is based
on priority constraints where demand is first met from renewable energy
sources followed by energy from fossil fuels. Secondly, the thesis discusses
the modelling and prediction of extremely high quantiles of solar power.
The methods used are a semi-parametric extremal mixture (SPEM), generalised
additive extreme value (GAEV) or quantile regression via asymmetric
Laplace distribution (QR-ALD), additive quantile regression with covariate
t (AQR-1), additive quantile regression with temperature variable (AQR-2)
and penalised cubic regression smoothing spline (benchmark) models. The
predictions from this study are valuable to power utility decision-makers
and system operators in knowing the maximum possible solar power which
can be generated. This helps them make high-risk decisions and regulatory
frameworks requiring high-security levels. As far as we know, this is the first
application to conduct a comparative analysis of the proposed robust models
using South African solar irradiance data. The interaction between global
horizontal irradiance (GHI) and temperature helps determine the maximum
amount of solar power generated. As temperature increases, GHI increases
up to the point that it increases at a decreasing rate and then decreases.
Therefore, system operators need to know the temperature range in which
the maximum possible solar power can be generated. The study used the
multivariate adaptive regression splines and extreme value theory to determine
the maximum temperature to generate the maximum GHI ceteris
paribus. Lastly, the study discusses extremal dependence modelling of GHI
with temperature and relative humidity (RH) using the conditional multivariate
extreme value (CMEV) and copula modes. Due to the nonlinearity
and different structure of the dependence on GHI against temperature and
RH, unlike previous literature, we use three Archimedean copula functions:
Clayton, Frank and Gumbel, to model the dependence structure. This work
was then extended by constructing a mixture copula model which combined
the Frank and Gumbel models. One of the contributions of this thesis is the
construction of additive quantile regression models for forecasting extreme
quantiles of electrical load, which are then used in solving the UC problem
with bounded MILP with priority constraints. The other contribution is developing
a modelling framework that shows that GHI converges to its upper
limit if temperature converges to the upper bound. Another contribution is
constructing a mixture of some copulas for modelling the extremal dependence
of GHI with temperature and RH. This thesis reveals the following key
findings:
(i) the additive quantile regression model is the best-fitting model for
hours 18:00 and 19:00. In contrast, the linear quantile regression model is
the best-fitting model for hours 20:00 and 21:00. The UC problem results
show that using all the generating units, such as hydroelectric, wind power,
concentrated solar power and solar photovoltaic is less costly.
(ii) the AQR-2 was the best-fitting model and gave the most accurate
prediction of quantiles at τ = 0.95, 0.97, 0.99 and 0.999, while at 0.9999-
quantile, the GAEV model had the most accurate predictions.
(iii) the marginal increases of GHI converge to 0.12 W/m2 when temperature
converges to 44.26 ◦C and the marginal increases of GHI converge
to −0.1 W/m2 when RH converges to 103.26%. Conditioning on GHI, the
study found that temperature and RH variables have a negative extremal
dependence on large values of GHI.
(iv) the dependence structure between GHI and variable temperature
and RH is asymmetric. Furthermore, the Frank copula is the best-fitting
model for variable temperature and RH, implying the presence of extreme
co-movements.
The modelling framework discussed in this thesis could be useful to decisioniii
makers in power utilities, who must optimally integrate highly intermittent
renewable energies on the grid. It could be helpful to system operators that
face uncertainty in GHI power production due to extreme temperatures and
RH, including maintaining the minimum cost by scheduling and dispatching
electricity during peak hours when the grid is constrained due to peak load
demand.NR
Hydrothermal synthesis of nano-scaled pure, Sn-doped, and Zn-doped Co3O4 structures and their gas sensing applications
No full textM. Sc. (Chemistry)Department of ChemistryDepartment of Science and Innovation CSIR Inter - Programme Bursary CSIR, Minte
Assessing climatic and non-climatic impacts on smallholder maize production in Tshimapha Irrigation Scheme, Limpopo Province.
No full textMENVSCDepartment of Geography and Environmental SciencesGlobally, climatic extremes and non-climatic factors are a major concern due to their emerging
and expected impacts on maize production. Climatic extremes come through drought and floods,
whilst non-climatic factors include lack of education, poor management, and lack of support. The
study evaluated the impacts of climatic extremes and non-climatic factors on the production of
maize yield and further examined measures for sustainable production of maize yield in
Tshimapha Irrigation Scheme, Limpopo Province of South Africa. The irrigation scheme was
established in the 1960s, and today has 115 smallholder farmers, each having 1.5 hectares.
Climate data was obtained from the Agricultural Research Council (ARC), South African Weather
Services (SAWS) and from literature. Questionnaires were administered among the 115
smallholder farmers. The key informant interviews were conducted among the farmer’s leaders,
community leaders and extension officers. The extension officer and smallholder farmers assisted
with generating maize yield data. For the first objective, rainfall data was analysed using Mann-
Kendall test analysis in R-Studio. Furthermore, Sen’s slope was also done to determine the
magnitude of the trend of the rainfall, monthly, seasonal, and yearly and questionnaires were
analysed using Microsoft Excel Version 2310. For the second objective, the Standardized
Precipitation Index (SPI) was analysed using rainfall data in Microsoft Excel, and the last
objectives were analysed using Statistical Package for the Social Sciences (SPSS) by looking at
the percentage distribution. The findings of this study indicated an increase in the intensity and
amount of rainfall received during flood years, with floods peaking in January and February. The
SPI indicated that the area is not prone to severe drought as it is mountainous. The highest
production of maize yield was 3.4 tons, with the least being 1 ton per year (based on the available
data). Water and land for farming in the scheme were sufficient before the establishment of the
Mutshedzi dam, which restricts access to dam water, and the land taken for some of the farmers
during the establishment of the dam. This study is in response to national, regional, and global
demand for knowledge on how smallholder farmers can adapt to erratic climates and in support
of achieving the Sustainable Development Goal (SDG) Number 2. This study can be useful the in
working towards alleviating challenges experienced by smallholder farmers in South Africa to
ensure sustainability in smallholder production.National Research Foundation (NRF
Iphungwa Ngezithebe: Exploring Umaskandi in The Fourth Industrial Revolution Threats and Opportunities
No full textPh. D. (African Studies)Department of Indigenous Knowledge System and Heritage StudiesThe phenomenon of umaskandi, which was the adaptation and continuation of a deep-seated Indigenous Isizulu culture of music-making, has become a commodity over several decades and has been monetised. Social advancement has meant that cultural industries, such as umaskandi, could not resist technological advances that have determined its production, dissemination, and reception. The production side of umaskandi has seen the introduction of new technologies that created entirely new ways of serving existing needs. The acceleration of innovations and the velocity of disruption are hard to comprehend or anticipate. However, umaskandi's inception and subsequent development can be traced back to several previous periods of industrialisation. Currently, the world is in the midst of the Fourth Industrial Revolution's perceived state that it will not spare any industry, including umaskandi. While these far-reaching developments have been taking place, scholarship on the critical role of stakeholders, such as the music industry value chain, in bringing umaskandi to the present state has been mute. This study explores umaskandi and The Fourth Industrial Revolution depending on the appropriate phenomenological research approach. Potential threats and opportunities to the survival of umaskandi in the Fourth Industrial Revolution have been identified during this exploration. Interviews, conversations, literature reviews, action research, focus meetings, analysis of diaries and other personal texts were the main modes of data gathering. It is envisaged that this study will generate and arm the music industry with an informed outlook on the state of umaskandi genre, which is more pressing as we move through the Fourth Industrial Revolution. Furthermore, it is anticipated that, through this study, detailed and comparative insight into the survival and
the appreciation of opportunities presented by the Fourth Industrial Revolution will promote the genre. Therefore, it is hoped that this study will benefit umaskandi, its practitioners, music education, and the music business.National Research Foundation (NRF
Strategies to improve support for children heading families in Limpopo Province, South africa
No full textPh.D. (Nursing Science)Department of Advanced Nursing ScienceBackground: The nonexistence of parents or adult caregivers in children’s lives is experienced by many children worldwide. Basic needs such as food, shelter, clothing, medical care, and protection from harm are among the many challenges faced by children heading families. Children heading families can be supported and live a quality life beyond the hardships they experience. A holistic approach can alleviate the hardships experienced by children heading families, through embarking on the identification of strategies to improve support for children heading families.
Purpose: The purpose of this study was to develop strategies to improve support for children heading families in Limpopo province, South Africa.
Setting: The study was conducted at the homes of children heading families and chief’s kraal of Vhembe and Mopani districts in Limpopo province, South Africa.
Phase 1: Research methodology: This study employed a qualitative, exploratory, and descriptive design. The population consisted of children heading families, children’s relatives, and community members. A non-probability purposive convenience sampling was used to select children heading families and snowball technique was used to select children’s relatives. Unstructured in-depth interview using an interview guide was used to collect data from children heading families and children’s relatives. Central questions were used to collect data from children heading families and children’s relatives. Focus group discussions were used to collect data from community members. The sample size of participants was determined by data saturation. Data was analyzed using Tech’s eight-step method. Data was transcribed verbatim, translated into English, and kept safe. A clearance certificate was obtained from the University of Venda Research Ethics Committee. Permission to conduct the study was requested from the traditional leaders of the villages. Ethical considerations and measures to ensure trustworthiness were considered. Children who agreed to participate voluntarily signed an assent form, and children’s relatives and community members signed consent forms.
Findings: The findings of the study revealed psychological, financial, social, and educational support challenges for children heading families, relatives, and community members. Children’s relatives and community members inadequately support children heading families.
Phase 2: Development of strategies
The researcher's 2020 study on the experiences of children heading families, revealed that children heading families were not receiving enough support from their relatives and community members. The findings prompted the researcher to conduct a study on the development of strategies to improve support for children heading families.
Phase 3: Validation of strategies
As stated in Chapter One, the study's objective guided the development of strategies. Validation of the strategy employed a qualitative approach using unstructured in-depth interviews. A group of expert panelists validated the results using the e=Delphi method. The expert panelists were retired registered nurses, retired educators, curriculum advisers, psychologists, social workers, pastors, self-employed, registered nurses, educators, traditional leaders, and ex-police. All experts had extensive experience and knowledge of taking care with children.
Findings: The study revealed that children heading families face numerous challenges without adequate support from their relatives and community members. The study focused on the development of strategies to improve support for children heading families.
Recommendations: Constant monitoring by children’s relatives and community members on the safety of children heading families. Protecting the safety of children heading families should be the Government's top priority and responsibility, especially in villages. Social workers are to visit the homes of children’s heading families regularly to constantly monitor the challenges faced by children. The traditional leaders play a crucial role in the communities and should be more involved in matters involving children heading families in their villages, and ought to have more authority over their roles and responsibilities. Educators should be provided with training on how to deal with children who come from families with no parent or caregiver.
Conclusion: The findings of this study revealed that children heading families experience ineffective psycho-social, educational, financial, religious and spiritual challenges.NR
The Effects of the Foster-care Backlog on Prospective Beneficiaries in Thulamela Municipality, Vhembe District: Limpopo Province
No full textM. A. (Social Work)Department of Social WorkThe goal of foster care is to ensure that children are provided with the necessary care and protection they are entitled to as children which is intended to allow them to , grow and develop in a safe and healthy environment. However, there is a backlog of applications presenting a severe challenge to the Department of Social Development, thus, negatively impacting the lives of its intended beneficiaries.
The aim of the study was to explore the effects of the foster-care backlog on prospective beneficiaries in the Thulamela Municipality, Vhembe District of the Limpopo Province. A qualitative research approach was employed to achieve the above aim and to understand the participants’ perceptions. The objectives of the study were to explore the contributory factors for the non-placement of prospective beneficiaries on the foster-care grant system; to describe the views of prospectivebeneficiaries on foster-care applications’ backlog; to describe the effects of foster-care applications’ backlog on prospective beneficiaries; to recommend solutions that could address the foster-care backlog. The study employed an exploratory qualitative research design to understand the phenomenon under study. Data was collected through semi structured and unstructured interviews. Non-probability sampling was utilized as a sampling procedure in the study. Data was analyzed thematically guided by Creswell (2017). The study employed the systems theory as the theoretical framework, based on that it is preceded on the fact that individuals and families do not exist in isolation but within broader societal relationships; if one part of the system is interrupted; it affects the whole system. If children are not taken care of, it destabilizes society’s fabric, which might exacerbate social ills.
The findings as per the participants responses highlighted that there is a lack of supervision on the other end leading to a backlog of unattended cases, It is evident that the social workers are not visible in supervision. Their difficulties to manage the foster care cases seems to be associated with a lack of resources, high caseload, and quality versus quantity in social services.
The participants maintained that they relied largely on their other grants such as old age grant to make a living.National Research Foundation (NRF
Unpacking community participation in the Integrated Development Planning process in Mbombela Local Municipality, Mpumalanga Province, South Africa
No full textM.A. (Political Science)Department of Arts and Social SciencesDuring the apartheid era in South Africa, most black people were banned from participating in government planning processes. After 1994, the black democratic government took power and sought to address apartheid practices by enacting key policies to transform local government. As a planning instrument for local government, the integrated development plan (IDP), was seen as one of the mechanisms for including residents in policy and decision making. This research unpacked the participation of the community in the integrated development planning process. The study objectives were to conceptualize the understanding of community participation by the participants, examine the knowledge of the participants about the IDP process in the local municipality of Mbombela, identify factors that hinder participation in community meetings, and recommend strategies to improve the effectiveness of community participation in the IDP. The qualitative approach was used to collect data from 16 participants through semi-structured interviews. The data in this study were analysed using thematic analysis. The study found that one of the main issues that made it difficult for community members to engage successfully during IDP sessions was the use of English and political jargon. Based on this finding, it is recommended that the local language be used extensively during IDP meetings. Furthermore, it is necessary to simplify and unpack complex development concepts for residents, to facilitate their understanding of the issues discussed and the challenges at hand.NR