Cape Peninsula University of Technology
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Numerical study of non-linear spectroscopy and four-wave-mixing in two and multi-level atoms
No full textThesis (MTech (Electrical Engineering))--Cape Peninsula University of Technology, 2018.In this research, we undertake a numerical study of the interaction between
laser beams and two as well as multi-level atoms. The main aim of this
research is to obtain a deeper understanding of laser-atom interactions and
non-linear processes such as optical four-wave mixing. This work will supplement
experiments to be conducted by other members of the group, who
are involved in generating entangled photons via four-wave mixing in cold
rubidium atoms.
We begin by performing a basic study of the interaction between laser
beams and two-level atoms as an aid to gain knowledge of numerical techniques,
as well as an understanding of the physics behind light-atom interactions.
We make use of a semi-classical approach to describe the system where
the atoms are treated quantum mechanically and the laser beams are treated
classically. We study the interaction between atoms and laser beams using
the density matrix operator and Maxwell's equations respectively. By solving
the optical Bloch equations for two-level atoms we examine the atomic
populations and coherences and present plots of the density matrix elements
as a function of time. The e ects of various parameters such as laser intensity,
detuning and laser modulation have been tested. The behaviour of
the laser beam as it propagates through the atomic sample is also studied.
This is determined by Maxwell's equation where the atomic polarization is
estimated from the coherence terms of the density matrix elements.French South African Institute of Technology
National Research Foundatio
Poultry slaughterhouse wastewater treatment using a static granular bed reactor (Sgbr) coupled with a hybrid sidestream membrane bioreactor
No full textThesis (MTech (Chemical Engineering))--Cape Peninsula University of Technology, 2017.An increase in the demand for poultry products coupled with the potable water shortages
currently experienced in South Africa (SA), attributed to climate change among other factors,
makes it crucial for SA to develop water conservation strategies to minimize potable water
consumption by water-intensive industries, such as the poultry industry. The development of
innovative wastewater treatment processes is therefore paramount in attempting to
counteract the large quantity of wastewater generated as well as to manage the
environmental health concerns arising from poultry slaughterhouse wastewater (PSW)
discharge into the environment. Moreover, increasing wastewater treatment costs and the
implementation of increasingly stringent government legislation to mitigate environmental
pollution whilst minimizing fresh water source contamination, requires that wastewater such
as PSW, be adequately treated prior to discharge.
This study, investigated the feasibility of treating PSW from a poultry slaughterhouse to: 1) a
water quality standard compliant with industrial wastewater discharge standards and 2) for
possible re-use purposes. The performance of a lab-scale PSW treatment system consisting
of an anaerobic static granular bed reactor (SGBR) followed by single stage nitrificationdenitrification
(SSND) bioreactor and sidestream ultrafiltration membrane module (ufMM)
post-treatment systems, were evaluated, with the objective being to: assess the treatment
efficiency of the individual treatment systems namely; the SGBR, SSND bioreactor, and
ufMM, under varying operational conditions, as well as to determine the performance of the
overall designed PSW treatment system.
The down-flow SGBR (2 L) was used to reduce the organic matter (COD, BOD5, and FOG)
and total suspended solids (TSS) in the PSW. Anaerobic granules from a full-scale
mesophilic anaerobic reactor treating brewery wastewater were used to inoculate the SGBR,
and the PSW used as feed was obtained from a local poultry slaughterhouse (Western Cape,
South Africa). The SGBR was operated continuously at mesophilic temperature (35-37 °C)
without pH modification and under varying HRTs (24, 36, 48, 55, and 96 h) and OLRs (0.73
to 12.49 g COD/Lday), for a period of 138 days. The optimization of the SGBR, with regard to
a suitable HRT and OLR, was determined using response surface methodology (RSM) and
Design Expert® 10.0.3 statistical software. Periodic backwashing of the SGBR system was
performed using stored effluent, i.e. treated PSW
Emergent literacy and agency among disadvantaged parents and caregivers
No full textThesis (MEd)--Cape Peninsula University of Technology, 2017.A qualitative investigation into the emergence of literacy among five adult socio-economically disadvantaged subjects in a semi-rural setting complements concerns that a lack of specific forms of cognitive input during pre-school years has a negative impact on later progress in formal schooling. The subjects achieved levels of literacy that enabled them to play leadership roles in their communities although they had experienced limited or no formal education during their formative years.
Using a GTM process the researcher identifies seven common themes that emerge from analysis of data from interviews and focus groups that explore the subjects’ perceptions of conditions that had promoted their literacy. These themes suggest that the subjects’ competence in literacy was facilitated by non-cognitive conditions including personal aspirations; resilience; disciplinary regimes in the home; voice; a nurturing mentor; community resources and ability to exercise agency.
The researcher concludes that these themes could be important in contributing towards an understanding that developing children’s agency during early childhood may be more significant to achieving effective levels of literacy than the current focus on attaining academic skills at standards that disadvantaged children have difficulty in achieving
The effects of gentrification and sustainable cultural tourism development in the Bo-Kaap, Cape Town
No full textThesis (MTech (Tourism and Hospitality Management))--Cape Peninsula University of Technology, 2017.The study site is the Bo-Kaap area in Cape Town. Negative and positive changes within interrelated physical, social and economic spheres have resulted from gentrification, an urban development phenomenon. These changes need to be managed responsibly. This study problem sought to establish whether the traditional inhabitants of the Bo-Kaap are being replaced by a ‘new generation’ of inhabitants because of gentrification, and how negative and positive changes in the Bo-Kaap could be minimised and maximised respectively, through gentrification, by adopting a sustainable cultural tourism approach.
A historical background of the Bo-Kaap reveals the history, culture and religion of this area, and highlights the special customs and traditions within the Bo-Kaap as potential areas of sustainable cultural tourism development to mitigate gentrification. A comprehensive literature review on gentrification and tourism as separate and interrelated development processes is presented. The literature review investigates gentrification and its effects as a phenomenon; the relative forms of gentrification across an international, national and local setting, refined to the Bo-Kaap; tourism and the nature of the industry and its development; and finally, tourism gentrification as an interconnected system
An evaluation of access to health care : Gugulethu Community Health Clinic
No full textThesis (MTech (Public Management))--Cape Peninsula University of Technology, 2017.The purpose of this study was to examine the problem of access to health care centres in the Western Cape and to forward recommendations that will improve access to health care facilities in the Western Cape. The first objective of the study was to identify trends in primary health care looking at Nigeria, with the view of learning lessons of experience. Secondly, the study provided an overview of the South African health care system. The study further examined the problems around access to Gugulethu Community Health Clinic. The research objectives were directly linked to the composition of chapters.
The study utilised a mixed-method approach of quantitative and qualitative approaches. This method is called multi-method approach. The purpose of combining the two approaches was to understand the research problem from a subjective and objective point of view, as well as to provide an in-depth understanding of a research topic, which led to more reliable research results. Data collection was acquired by utilising a structured questionnaire and personal observations. Two groups of respondents participated in the study inter alia: the patients and the staff of Gugulethu Community Health Clinic
Optimisation of solid rocket motor blast tube and nozzle assemblies using computational fluid dynamics
No full textThesis (MTech (Mechanical Engineering))--Cape Peninsula University of Technology, 2017.A framework for optimising a tactical solid rocket motor nozzle is established and investigated
within the ANSYS Workbench environment. Simulated results are validated
against thrust measurements from the static bench firing of a full-scale rocket. Grid independence
is checked and achieved using inflation based meshing. A rocket nozzle contour
is parametrized using multiple control points along a spline contour. The design of experiments
table is populated by a central composite design method and the resulting response
surfaces are used to find a thrust optimised rocket nozzle geometry. CFD results are based
on Favre-mass averaged Navier-Stokes equations with turbulence closure implemented with
the Menter SST model. Two optimisation algorithms (Shifted Hammersley Sampling and
Nonlinear Programming by Quadratic Lagrangian) are used to establish viable candidates
for maximum thrust. Comparisons are made with a circular arc, Rao parabolic approximation
and conical nozzle geometries including the CFD simulation there-off. The effect
of nozzle length on thrust is simulated and optimised within the framework. Results generally
show increased thrust as well as demonstrating the framework's potential for further
investigations into nozzle geometry optimisation and off-design point characterisation
An evaluation of communication tools in a hierarchical training institution : the case of a police academy in the Western Cape
No full textThesis (MTech (Business Administration))--Cape Peninsula University of Technology, 2017.Communication in a multi campus organization has always proven to be difficult (Coiera, 2006: 95). The research problem emanates from bad use or non-existent communication strategies in one of the SAPS Academies. The objective of this research was to examine how the management and staff in the Police Academy can break the communication barriers created by hierarchy and bureaucracy; develop guidelines for the management and staff members on how they can create effective communication channels in the Academy, examine how poor communication impacts negatively on the operations at a police academy, highlight how proper and timely communication can improve operation in the Academy and to identify and make recommendations on the ways the management and staff at the SAPS Academy can improve communication. The research was conducted to, critically evaluating the existing communication strategies applied in the SAPS Basic Training Academy; determine strengths and weaknesses of these strategies; consider the alternative strategies that can be utilised to manage communication in the Academy; identify, highlight, assess and explain the importance of effective communication in a Police Academy and draw attention to how effective communication can be used to improve projects. The methods employed in this research include qualitative and quantitative research, where open ended questions were utilised in obtain information and closed ended questions to fill in the gaps on the information obtained from open ended questions. The study adopted the qualitative and quantitative research method to answer the research question and data interpretation was based on Microsoft Excel. This method was deemed to be the most effective for collection of the kind of data and numerical (quantifiable) data is considered objective. On Section B, a Likert-type questionnaire comprising closed-ended questions was the measurement instrument. Answer choices were graded from 1 to 5, being strongly agree, agree, indifferent, disagree and strongly disagree. Based on the different models that were studied, the researcher then suggested a tentative model that could be used.
The population comprised of all the 147 employees of one of the SAPS Academies in the Western Cape, and questionnaires were distributed to all the 84 employees that were on duty on a particular day in this academy. The findings indicated that organisation communicate yields better results than those that do not communicate.
The study highlighted the communication problems at the academy and came up with model/ solution to the current situation. The respondents used in the study gave a lot of suggestions that could be used in the academy. The frequency tables utilised will be useful as the reader could see the favourite suggestions or preferences by the people
Implementation of a reverberation chamber for electro-magnetic compatibility measurements
No full textThesis (MTech (Electrical Engineering))--Cape Peninsula University of Technology, 2017.This research project focuses on the implementation of a Reverberation Chamber (RC) by the transformation of an existing electromagnetically shielded room. The reverberation chamber is a kind of shielded room designed to create a statistically random internal electromagnetic environment. The reverberating environment makes it possible to obtain high field strengths from a relatively low input power. The electric fields in the chamber have to be stirred to achieve a statistically uniform field.
The first part of this thesis presents an overview of reverberation chamber principles and preliminary calculations are done: the lowest usable frequency is estimated to be close to 300 MHz from empirical criteria. Modelling of the statistical environment is then presented, where electromagnetic quantities are characterised by probability density functions (Gaussian, Rayleigh and exponential); correlation issues are also presented.
Measurements are performed in the frequency range of 800 MHz – 4 GHz, dictated by the antennas available for this research study. An investigation of cable losses is conducted, followed by a discussion on measurement accuracy.
Mechanical stirrers are designed and manufactured. Electromechanical components are selected based on the literature study. Measurements are obtained through an automated setup using MATLAB®.
To verify that the RC, with its in-house designed mechanical stirrers, is well-operated, the stirring ratio is experimentally determined. After this first test, an exhaustive investigation of probability density functions is conducted, taking into account correlation issues. Measurements show that the quality factor of the chamber is close to 2000 at 3 GHz, and that 60 independent stirrer positions at 4 GHz can be used for statistical analyses.
Finally, the uniformity test is performed with an improved accuracy using frequency stirring. In conclusion, the CPUT RC passes the validation procedure according to the IEC 61000-4-21 standard by generating the required field uniformity within the accepted uncertainty level
The feasibility of high synthesis gas conversion over ruthenium promoted iron-based Fischer Tropsch catalyst
No full textThesis (MTech (Chemical Engineering))--Cape Peninsula University of Technology, 2017.One of the very promising synthetic fuel production strategies is the Fischer-Tropsch
process, founded on the Fischer-Tropsch Synthesis, which owes its discovery to the
namesake researchers Franz Fischer and Hans Tropsch. The Fischer-Tropsch Synthesis
(FTS) converts via complex polymerisation reaction a mixture of CO and H2 over
transition metal catalysts to a complex mixture of hydrocarbons and oxygen containing
compounds with water as major by-product. The mixture of CO and H2 (termed syngas)
may be obtained by partial oxidation of carbon containing base feedstocks such as coal,
biomass or natural gas via gasification or reforming. The Fischer-Tropsch (FT) process
thus presents the opportunity to convert carbon containing feedstocks to liquid fuels,
chemicals or hydrocarbon waxes, which makes, for instance, the monetisation of
stranded gas or associated gas a possibility.
The FT-process is typically carried out in two modes of operation: low temperature
Fischer-Tropsch (LTFT) and high temperature Fischer-Tropsch (HTFT). LTFT is
normally operated at temperatures of 200 – 250 °C and pressures of 10 – 45 bar to target
production of high molecular weight hydrocarbons, while HTFT is operated at 300 –
350 °C and 25 bar to target gasoline production.
The catalytically active metals currently used commercially are iron and cobalt, since
product selectivity over nickel is almost exclusively to methane and ruthenium is highly
expensive in addition to requiring very high pressures to perform optimally. Fe is much
cheaper, but tends to deactivate more rapidly than Co due to oxidation in the presence of
high H2O partial pressures. One of the major drawbacks to using Fe as FT catalyst is
the requirement of lower per pass conversion which necessitates tail gas recycle to
extend catalyst life and attain acceptable overall conversions. A more active or similarly
active but more stable Fe-catalyst would thus be advantageous. For this reason
promotion of a self-prepared typical LTFT Fe-catalyst with Ru was investigated.
A precipitated K-promoted Fe-catalyst was prepared by combination of co-precipitation
and incipient wetness impregnation and a ruthenium containing catalyst prepared from
this by impregnation with Ru3(CO)12. The catalysts, which had a target composition of
100 Fe/30 Al2O3/5 K and 100 Fe/30 Al2O3/5 K/3 Ru, were characterised using XRD, SEMEDX,
ICP-OES, TPR and BET N2-physisorption, before testing at LTFT conditions of
250 °C and 20 bar in a continuously stirred slurry phase reactor
Molecular characterisation of Mycobacterium Tuberculosis, clinical isolates obtained in the Khomas region, Windhoek, Namibia
No full textThesis (MSc (Biomedical Technology))--Cape Peninsula University of Technology, 2017.According to the Namibia National Tuberculosis Control Programme (NTCP) report of 2008, Namibia has one of the highest TB infection rates in the world with a case notification rate of 748/100,000. Rapid, specific and sensitive diagnosis of Mycobacterium tuberculosis (MTB) is needed for correct TB patient management. One of the aims of this study was thus to compare direct microscopy with two rapid molecular diagnostic tools (viz. GeneXpert MTB/RIF and Hain Genotype® MTBDR plus assay) for the identification of MTB from samples collected from the Khomas Region, Windhoek, Namibia. Only patients with positive TB sputum collected at the clinics and health facilities in the Khomas Region, Windhoek were eligible for the study. Three hundred and eighty-four samples were confirmed acid-fast positive by utilising the auramine staining method. The rifampicin (RIF) resistance profile detected by both molecular techniques was then compared for characterisation of the samples as drug resistant. Lastly, participants completed a survey, which included questions related to demographic and epidemiological data. Demographic data included patient age, gender, region of residence and history of treatment. The data was collected using a structured questionnaire and was captured in an Excel spreadsheet. It was then imported into Statistical Package for Social Sciences (SPSS) Version 25 for data analysis. A memorandum of understanding was also signed with the Namibia Institute of Pathology (NIP) to obtain permission to use their samples and the equipment at their site