Central University of Technology
Central University Of Technology Free State - LibraryCUT, South AfricaNot a member yet
2545 research outputs found
Sort by
Optimization of a Real Time Web Enabled Mixed Model Stochastic Assembly Line to Reduce Production Time
No full textPublished ArticleThe role of assembly lines has never been more critical as it is now
with the world entering the 4th Industrial Revolution, commonly referred to as
Industry 4.0. If the focus of the previous industrial revolution was on mass production,
the focus of Industry 4.0 is on mass customization. One of the major
changes mass customization brings about to an assembly line is the need for them
to be autonomous. An autonomous assembly line needs to have the following key
features; ability to provide a ubiquitous input, the ability to optimize the model in
real time and achieve product variety. Product variety, in this context, refers to
different variants of the same product as determined by the user. Assembly lines
that make provision for introducing product variety are termed as mixed-model
assembly lines. Mixed-model assembly lines become stochastic in nature when
the inputs are customized as time cannot be predetermined in a stochastic process.
The challenge, as it stands, is that there are limited discussions on real-time
optimization of mixed model stochastic assembly lines. This paper aims to
highlight this challenge by considering the case study of optimizing a mixed
model assembly line in the form of a water bottling plant. The water bottling plant,
which needs to produce two variants of the bottled water, 500 ml, and 750 ml,
takes customer inputs through a web interface linked to the model, thereby making
it stochastic in nature. The paper initially details how the model replicating the
functioning of the water bottling plant was developed in MATLAB. Then, it
proceeds to show how the model was optimized in real time with respect to certain
constraints. The key results of the study, among others, showcase how the optimization
of the model is able to significantly reduce production time
Improving Occupational Health And Safety (OHS) In Construction Using Training-Within-Industry Method
Get PDFResearch PaperPurpose – The manufacturing industry is a well-known source of interventions adapted to solve problems
in the construction industry. The use of Training-Within-Industry (TWI) is one such intervention adopted in
the construction industry to solve the construction problem relating to occupational health and safety (OHS).
The objectives of TWI are to help the industry to transfer knowledge and skills from management to the
employees. Therefore, the purpose of this paper was to investigate whether TWI can reduce OHS problems by
promoting “learning by doing” on construction sites.
Design/methodology/approach – A case-based-research method was used to investigate the reported
OHS problems in the construction industry in South Africa. The data were quantitative and qualitative in
nature; the questionnaire survey, semi-structured interview and focus group interview techniques were used
to collect data in the study.
Findings – The findings provide a better understanding of the human contributions influencing the
behaviour of people causing accidents on construction sites. The data show that construction project leaders
struggle to promote “learning by doing” because of inappropriate behaviour, lack of communication and
inadequate training provided to new workers on construction sites. Also, there is significant scope for TWI
deployment in construction because of the inability of supervisors or management to promote “learning by
doing” on construction sites.
Practical implications – Based on the research findings, it is discovered that OHS is a serious concern in
the construction industry. Therefore, the adoption of learning by doing on a construction site would help to
improve OHS outcome.
Originality/value – The study highlights the need to introduce TWI on construction sites to reduce
human failure causing accidents. TWI could lead to improving the knowledge- and skills-transfer
programmes for construction workers in favour of better safety performance
Assessing Strategies For Improving The Social Security Of Construction Workers In Zimbabwe
No full textPublished ArticlePURPOSE OF RESEARCH:
The aim of this research is to propose corporate social
responsibility strategies that can improve social security
of construction workers in Zimbabwe.
METHOD:
A questionnaire survey obtained perceptions from site/
project managers and skilled and semi-skilled workers
from construction companies and thirteen building
projects, respectively, in Harare, Bulawayo and Shurugwi.
FINDINGS:
Site and project managers prioritised training workers
on effects and the need for minimisation of consumption
of natural resources within the communities while the
workers considered outplacement services, retraining and
severance benefits as most essential to them. RESEARCH LIMITATIONS:
Responses were generated from site/project managers
who may not be owners of construction companies, but
have considerable influence on ways to improve the
productivity and welfare of workers.
PRACTICAL IMPLICATIONS:
The study encourages inclusive and well-resourced social
responsibility programmes for construction workers.
ORIGINALITY/VALUE:
The corporate social responsibility strategies identified
will positively enhance the welfare of workers
Strategic Priorities for Cultivating Commitment Amongst Academic Staff: The Militating Effect of Workplace Spirituality
Get PDFOrientation: Organisational commitment remains an ongoing concern for organisations,
especially universities that often struggle to retain academic staff. Universities cannot operate
or fulfil their mandate to society without the critical competencies of academic staff.
Research purpose: This investigation focused on workplace spirituality as a militating factor
in enhancing the commitment of academic staff.
Motivation for the study: As organisational commitment remains a challenge for universities,
this article contributes to a theoretical and empirical understanding of the militating influence
of workplace spirituality. The study is underpinned by social learning theory and proposes
strategic priorities to universities – informed by an empirical study conducted amongst
academic staff members at a South African university.
Research approach/design and method: The study employed a quantitative research approach
and a structured questionnaire was administered to 285 academic staff members (ranging
from junior lecturers to professors) of a South African university. The research design was a
survey and, as a single university formed part of the study, regression analysis was used to
establish the relationship between workplace spirituality and organisational commitment.
Main findings: The empirical findings showed a strong linear relationship between workplace
spirituality and organisational commitment. A regression formula was developed to
statistically calculate the commitment score of individuals.
Practical/managerial implications: The study proposed strategic priorities that may be useful
to university management and human resource practitioners to cultivate increased commitment
amongst academic staff.
Contribution/value-add: The study contributed empirical evidence of the militating effect of
workplace spirituality on organisational commitment, implying that workplace spirituality is
a predictor for organisational commitment
A Health and Safety Model for Occupational Exposure to Radiofrequency Fields and Static Magnetic Fields from 1.5 and 3 T MRI scanners
Get PDFOriginal PaperThe exposure ofMRI staff to SMFs and RF fields in theMRI units happen as a result of their induced movement in theMRI room
during patients’ examination. Exposure to SMFs among health care workers has been associated with vertigo, nausea, increased
heart rate, hypothermia and metallic taste in the mouth. The only known adverse effects associated with RF fields’ exposure
include induced tissue heating, and the scientific arguments regarding non-thermal effects are inconclusive. The emission of
MRI-related electromagnetic fields and exposure of workers to RF energy and SMFs can be reduced through implementation of
reasonably practicable control measures. This study attempts to recommend the hierarchy of controls that can be implemented in
the MRI units to reduce emissions and exposure of MRI staff to RF energy and SMFs. The controls are recommended based on
exposure assessment conducted to quantify the exposure levels and self-reported priori-related and unrelated health consequences.
In the MRI units, elimination is an impractical measure, hence, the implementation of engineering and administrative
control measures as well as the utilisation of personal protective equipment (PPE) are recommended to mitigate exposure.
Engineering controls include modification of MRI scanners to reduce emissions while administration controls include the design
of work schedules and processes to be adaptive by MRI staff. PPE is recommended as a last resort and include protective
equipment that are fit to reduce exposure arriving to workers. In South Africa, there is no legislation to assist in enforcing
exposure limits and as a result, exposure levels are not monitored. The model of this kind could assist in reducing exposure levels
in the MRI units and substantially reduce exposure-related effects amongst workers
A Multi Institutional Comparison of Imaging Dose and Technique Protocols for Neonatal Chest Radiography
Get PDFPublished ArticleIntroduction: The focus on paediatric radiation dose reduction supports reevaluation of paediatric imaging
protocols. This is particularly important in the neonates where chest radiographs are frequently
requested to assess respiratory illness and line placement. This study aims to assess the impact of
neonatal chest radiographic protocols on patient dose in four hospitals in different countries.
Methods: Exposure parameters, collimation, focus to skin distance (FSD) and radiation dose from 200
neonatal chest radiographs were registered prospectively. Inclusion criteria consisted of both premature
and full-term neonates weighing between 1000 and 5000 g. Only data from the examinations meeting
diagnostic criteria and approved for the clinical use were included. Radiation dose was assessed using
dose area product (DAP).
Results: The lowest DAP value (4.58 mGy cm2) was recorded in the Norwegian hospital, employing a high
kVp, low mAs protocol using a DR system. The Canadian hospital recorded the highest DAP (9.48), using
lower kVp and higher mAs with a CR system, including the addition of a lateral projection. The difference
in the mean DAP, weight, field of view (FOV) and kVp between the hospitals is statistically significant
(p < 0.001).
Conclusion: Use of non-standardised imaging protocols in neonatal chest radiography results in differences
in patient dose across hospitals included in the study. Using higher kVp, lower mAs and reducing
the number of lateral projections to clinically relevant indications result in a lower DAP measured in the
infant sample studied. Further studies to examine image quality based on exposure factors and added
filtration are recommended.
Implications for practice: Reevaluation of paediatric imaging protocols presents an opportunity to reduce
patient dose in a population with increased sensitivity to ionising radiation.
© 2019 The College of Radiographers. Published by Elsevie
In Vitro Antibacterial, Antioxidant and Anti-Inflammatory Effects of Senecio Asperulus and Gunnera Perpensa from Mohale’s Hoek, Lesotho
Get PDFOriginal ArticleBackground: Traditional medicinal plants have been widely used to treat or manage various
ailments for centuries in Lesotho. With an increase in multi drug resistance and undesired
adverse events to current drugs challenges, there is a need for alternative drugs. Aim: In
this study we aimed at the investigation of antibacterial, antioxidant and anti-inflammatory
effects of Senecio asperulus and Gunnera perpensa roots extracted in three solvents of
different polarities. Materials and Methods: Antibacterial activity was determined using
the disc diffusion method, while antioxidant activity was determined using free radical
scavenging of 2,2-diphenyl-1-picrylhydrazyl and the ferric reducing antioxidant power assay.
The Lipopolysaccharide (LPS) stimulated RAW 264.7 mouse macrophage in vitro model was
used to evaluate the anti-inflammatory activity of both plants. Resveratrol was used as a
positive control. Results: Methanol extracts of Senecio asperulus inhibited microbial growth
even at the lowest concentration of 50 μg/ml. Senecio asperulus dichloromethane extract was
active on most bacteria with MIC’s between 50 μg/ml and 500 μg/ml. However, the water and
methanol extracts of Gunnera perpensa had no activity against all organisms tested. Aqueous
extracts of Senecio asperulus and Gunnera perpensa showed free radical scavenging activity
yielding EC50 values of 100 μg/ml and 25 μg/ml, respectively. The aqueous extracts of Senecio
asperulus showed moderate anti-inflammatory activity from 50 to 200 μg/ml. while the
methanol extract was at 200 μg/ml and with no cytotoxicity. No anti-inflammatory activity was
observed from all Gunnera perpensa extracts using LPS-induced macrophages, this suggests
that this species may be using other mechanisms for anti-inflammatory activity. Conclusion:
The antibacterial, antioxidant and anti-inflammatory activities observed from water extracts
of Senecio asperulus support its ethnomedicinal use for the management of inflammation
related diseases
Isothermal Crystallization Kinetics and Morphology of Double Crystalline PCL/PBS Blends Mixed with a Polycarbonate/MWCNTs Masterbatch
Get PDFPublished 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
A Rapid and Convenient Synthesis of Acridine Derivatives Using Camphor Sulfonic Acid Catalyst
Get PDFPublished Articl
Student Perspectives of a Peer Mentorship Programme Introduced at a University of Technology in South Africa
Get PDFPublished ArticleStudent peer mentorship programmes have been implemented at many higher education institutions to combat high attrition and failure rates among first-year students. Despite the many perceived benefits of such programmes, key challenges to its implementation and sustainability remain. The purpose of this article is to present students’ perspectives of a student peer mentorship programme that was introduced at a university of technology in South Africa in 2013, so as to validate its viability for African students. Focus group interviews were conducted with senior students registered in the Faculties of Management and Engineering. The results point to five key benefits; namely, better adaption to higher education, an impact on learning and understanding, social support, the acquisition of graduate attributes, and personal development. Two key challenges were identified; namely, poor attendance of mentees at planned events and a lack of support from senior students at the university. It is recommended that such programmes be incorporated into the curriculum of all academic programmes, and especially engineering ones, so as to improve academic student support