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Appraisal Of Production Practices Of Goat Farmers In Selected District Of The Kwazulu-Natal Province
Get PDFDissertationThe study was conducted to assess management practices by goat farmers in uMgungundlovu of the KwaZulu-Natal province. A total of 70 farmers were interviewed by means of structured questionnaires. The average farm size in the uMgungundlovu district is 108.3 hectares. Most farmers farm with indigenous veld goats (78.6%). A considerable number of respondents have a low level of education n= 28 (40%). Management activities performed by respondents included control of internal and external parasites which was done by 94% and 96% respectively. The diseases most vaccinated for were Pulpy kidney (61.5%) and Pasteurella (51.9%). n = 58 respondents (78.6%) grazed their animals on natural veld. An insubstantial percentage of respondents had cultivated pastures (15.7%) n=11. Respondents provided winter and summer supplementary feed (46%) and supplementary lick (83%). A total of 17 farmers (24.3%) had a specific breeding season. Breeding management activities were done by farmers, and 5.7% of respondents were testing bucks for fertility, while 18.6% were provided flush feeding and 11.4% performed pregnancy diagnoses.
Farmers culled animals that did not measure up to standard (39%), while 61% did not have a culling programme. A number of 57 farmers (81.4%) farmers had made an average amount of R33 614.29 from selling goats in the uMgungundlovu district, but 12.9% respondents were not willing to share their sales records. A small percentage of farmers (5.7%) did not keep financial records at all. The majority of the farmers (60%) sold their goats to private buyers (individuals). The majority of the farmers (36.2%) obtained their information from farmers’ days.
To discover what influence various management practices had on the production of goats, the following four production variables were investigated: conception rate, kidding percentage, mortality rate and weaning percentage. Management practices investigated were: internal parasite control, external parasite control, provision of supplementary feed during winter and summer, provision of supplementary lick, fertility testing of bucks before mating; provision of flush feed before breeding season starts; the presence of specific breeding seasons and pregnancy diagnosis. There was a statistical significance (P<0.05) in the conception rate where flush feeding was provided and a specific breeding season existed. A statistically significant higher kidding percentage with the control of internal parasites, provision of supplementary feed, flush feeding and the existence of a specific breeding season was obtained. There was a statistically higher weaning percentage with the provision of supplementary feed (P<0.05), flush feeding, the existence of a specific breeding season and pregnancy diagnosis
Comparative Genomics Of Mycobacteria: Identification Of Novel Anti-Tubercular Drug Targets
Get PDFThesisMycobacteria are aerobic, unicellular, highly pathogenic organisms, responsible for lethal diseases in humans and other animals. One of the most investigated of the Mycobacteria is Mycobacterium tuberculosis (M. tuberculosis), a deadly pathogen causing tuberculosis in humans, a continuously growing threat to mankind. The development of multidrug-resistant, extensively drug-resistant, and totally drug-resistant strains of M. tuberculosis, combined with the scarcity of new drug targets, suggests that new research is needed to explore the biology of M. tuberculosis to investigate new therapeutic measures against tuberculosis and set forth novel potential drug targets.
The genome sequence of M tuberculosis has been available for a while now on public databases, and a genome-based method can be used to help understand the adaptation/evolution of this pathogen. Comparative genomics provides us with the opportunity to attempt to understand the mechanism of pathogenesis, including pathways and functions shared among species, and also the physiologic differences, which can help address the pathogenic properties of M. tuberculosis. Comparing the genome of the pathogenic M.tuberculosis to that of a non-pathogenic mycobacterium, e.g. M. vanbaalenii, can shedsome light on what unique characteristic it is that makes M. tuberculosis more virulent and prone to developing resistance. Recognising any such uniqueness that can possibly be a drug target may ultimately lead to the development of a new drug in the fight against tuberculosis.
This study was performed to see if the use of comparative genomics can be used to identify unique genes that can possibly become novel drug targets. The whole genomes of 8 mycobacterial species belonging to six different niches (M. tuberculosis H37Rv, M.africanum GM041182, M. bovis AF2122/97, M. abscessus ATCC 19977, M. avium 104, M. leprae TN, M. marinum, and M. vanbalenii) were downloaded from TB database and compared using BLAST software. Genes unique to each of the species were identified.
The genome comparison of 8 different mycobacterial species belonging to 6 different niches revealed 200 genes unique to M. tuberculosis H37Rv. The uniqueness of 200 genes identified for M. tuberculosis H37Rv by genome comparison were further investigated by comparing the genes with available amino acid sequences to the genomes of 96 mycobacterial species. Functional classification of these genes was done using genome mapping with each of these genes with 5 upstream and 5 downstream proteins.
The study results indicated that genome comparison is a viable method to identify unique genes that in the quest to identify novel potential drug targets
High velocity impact properties of as-built and heat treated ti6al4v (eli) specimens built through direct metal laser sintering
Get PDFThesis (Master: Engineering: Mechanical Engineering)--Central University of TechnologyDirect metal laser sintering (DMLS) is a metal additive manufacturing (AM) technology specific to the company Electro Optical Systems (EOS). Generally, this technology is known as selective laser melting (SLM) and it fits in the broad category of powder bed fusion (PBF) (ASTM F2792-12a). The process is a laser-based technique that uses the digital input of CAD models to create three-dimensional (3D) parts from metallic powders. In the Centre for Rapid Prototyping and Manufacturing (CRPM), an EOSINT M280 system was used for building the DMLS parts for this study. The term, high velocity, is used to describe speeds in the range of 50 to 1500 m/s in ballistics. In general, the mechanisms that are activated in ballistic impact depend on the thickness, ductility, strength, stiffness, hardness, toughness, strain rate, density of the target, and velocity of the projectile. In order to get insight on the high velocity impact behaviour of the Ti6Al4V alloy, preliminary testing was conducted on wrought Ti6Al4V as a prelude to considerations of the as-built and stress relieved DMLS Ti6Al4V (ELI) alloy as an alternative to Rolled Homogeneous Armour steel (RHA) and aluminium alloy AA 5083 for high velocity impact applications. Preliminary ballistic impact testing of wrought Ti6Al4V involved the manufacturing of test plates of different thicknesses, and thereafter ballistic impact testing using 7.62 x 39 mm (.30 calibre) bullets travelling at an average velocity of 702 m/s. The preliminary testing of the wrought Ti6Al4V revealed that its minimum thickness to prevent through penetration was above 14 mm. This value was found to lie between 14 mm and 18 mm. Based on the foregoing, the value falls between that of RHA and AA 5083 at 11.43 mm and 19.8 mm, respectively. Fractographic analysis of the wrought Ti6Al4V plates further revealed that, although Ti6Al4V is usually classified as a ductile metal under normal loading conditions, when exposed to high velocity impact, the alloy exhibits both brittle and ductile behaviour. Microstructural analysis of the wrought Ti6Al4V revealed that the high strain rate imposed on the plates, brought about alteration of the microstructure during high velocity ballistic impact. This was clear from the gradually increasing refinement of grains and decreasing measured average values of the widths of -laths, radially away from the edges of the penetration holes of the projectiles. Both the refinement of grains and the decreasing average measured values of the widths of grains were a function of the high rise in temperature followed by cooling. The effect of impact on the plates tested was to create a compressive stress wave in the direction of impact (longitudinal axis of the penetration hole) and tensile stress waves in the radial and circumferential directions with respect to the penetration hole. These induced stresses tended to lengthen and widen the grains along the radial and circumferential directions, respectively. It was noted, however, that the predominant change in grains towards the edge of the hole was a reduction of size (refinement of grains). This suggested that the effect of grain refinement due to exposure to high temperatures overrode that of the induced stresses. In addition, the high strain rate and attendant high rise in temperature arising from high velocity impact was enough to cause the formation of adiabatic shear bands (ASBs), whose incidence reduced with distance away from the edge of the projectile hole. The ASBs were seen in this work to be sites in which cracks propagated and therefore formed paths for failure of the material. After the preliminary ballistic impact testing of wrought Ti6Al4V, a justification was formulated for investigation of the high velocity impact properties of as-built and stress relieved DMLS Ti6Al4V (ELI). The justification yielded values of optimum thickness for the DMLS alloy of 13.64 mm and 10.40 mm, based on the V50 ballistic limit and shear strain energy theories, respectively, which were lower than the respective values for wrought Ti6Al4V of 15.38 mm and 14 mm. Ballistic impact testing of as-built and stress relieved DMLS Ti6Al4V (ELI) also revealed a minimum thickness to prevent through penetration greater than 14 mm. This value fell short of the estimated value of 10.40 mm in the justification for testing the alloy, which can be attributed to the assumption made in the calculations of normal deformation with the usual high plastic deformation encountered at low strain rates. Visual inspection of the as-built and stress relieved DMLS Ti6Al4V (ELI) ballistically impacted plates unveiled plastic deformation, induced bulging and spalling on the entry side of the penetration holes for all the plate thicknesses. Furthermore, apart from the 8 mm thick plate, all the plates exhibited ductile failure on the exit side of the penetration hole, evidenced by the existence of petals there. Fractographic analysis of the as-built and stress relieved DMLS Ti6Al4V (ELI) plates revealed brittle behaviour at the entry points of the penetration holes and ductile behaviour at the exit points of the penetration holes for all the plate thicknesses. Microstructural analysis of the as-built and stress relieved DMLS Ti6Al4V (ELI) plates further revealed that the high strain rates imposed on the plates, also brought about alteration of the microstructure during high velocity ballistic impact, as was observed for wrought Ti6Al4V. This was evidenced by a gradual increase of the phase fraction towards the edge of the projectile hole. There was an attendant decrease in hardness towards the edge of the projectile hole as evidenced by the Vickers hardness measurements. It was posed that due to the low thermal conductivity of Ti6Al4V (ELI) of 6.7 W/m-K, the heat generated by the high induced strain rates during high velocity impact, could not be conducted away effectively from the point where it was generated. This retention of heat is thought to have led to softening of the material and the formation of ASBs near the edge of the projectile hole. Moreover, the average velocity of the projectiles and the related primary and secondary penetrations in the present work was high enough to induce a temperature rise above the beta transus temperature over the period of impact. Though the time periods of impact (typically is about 2 – 5 ms) are much shorter than the normal heat treatment periods typified by heating and soaking, cooling in the present case occurred at ambient conditions and may thus be considered as fast cooling. Therefore, while there was not enough time to support whole scale transformation of to grains upon impact, there was adequate time for grains to transform back to grains after impact to form lamellae. This effect was observed to reduce with distance away from the edge of the penetration hole. The results obtained from the studies here revealed that as-built and stress relieved DMLS Ti6Al4V (ELI) manufactured through the DMLS process using an EOSINT M280 system with standard process parameters, can be used for high velocity impact applications, such as in the military and the aerospace industry
Are Lower Preoperative Serum Sodium Levels Associated With Postoperative Surgical Site Infection? Results From A Propensity Matched Case-Control Study
Get PDFArticleBackground: We previously reported a statistical trend toward a harmful association between lower preoperative serum sodium
levels and surgical site infection (SSI) in South African (SA) laparotomy patients. Serum sodium tests are widely available and could
serve as a cost-effective method for preoperatively identifying patients at risk for SSI who might benefit from additional preventative
strategies. We sought to investigate the possible association between lower serum sodium levels and SSI further, in a larger sample of
SA patients undergoing various surgical procedures.
Objective: To determine if lower preoperative serum sodium levels are associated with SSI in SA surgical patients.
Method: This was a propensity matched case-control study involving data from 729 surgical patients who attended a quaternary
SA hospital between 01 January 2012 and 31 July 2016. Cases were defined as patients who developed SSI. Controls were defined as
patients who did not develop SSI. Multivariate logistic regression was used to investigate the association between preoperative serum
sodium levels (in mmol/L) and SSI.
Results: Lower preoperative serum sodium levels were associated with a higher risk of SSI (odds ratio per 1.0 mmol/L decrease in
serum sodium: 1.051, 95% confidence interval: 1.007–1.097; p = 0.026).
Conclusion: Although we report a statistically significant association between lower preoperative serum sodium levels and a higher
risk of SSI, the magnitude of this effect size (odds ratio) is minimal and clinically insignificant. Preoperative serum sodium levels are
unlikely to be useful for SSI risk stratification in our setting
Local Diagnostic Reference Levels (Ldrls) For Routine Chest X-Ray Examinations At A Government Hospital In The Northern Cape
Get PDFDissertationBACKGROUND
The use of ionising radiation in the medical field accounts for the largest contribution of radiation exposure to the human population. The extent of radiation received by patients undergoing X-ray examinations needs to be quantified to estimate the possibility of harm.
The focal point of the research is chest X-ray examinations since these examinations are the most commonly performed worldwide. The chest contains two radiosensitive organs, namely the thyroid and breast tissue. This research study is deemed critical because it demonstrates how dose optimisation can be achieved. Dose optimisation is achieved when the local diagnostic reference levels (LDRLs) of chest X-ray examinations of the research site are less than the international values.
The Directorate of Radiation Control (DRC) has not yet established LDRLs for radiological examinations. The data generated by this research could assist the organisation to baseline diagnostic reference levels (DRLs) for adult chest X-ray examinations in the Northern Cape.
RESEARCH QUESTION
The research question is:
What are the LDRLs for routine chest X-ray examinations at a government hospital in the Northern Cape?
OVERALL GOAL OF THE STUDY
The overall goal of this study was to determine LDRLs values for adult chest X-ray examinations. AIM OF THE STUDY
The aim of the study was to determine LDRLs for routine chest X-ray examinations in a diagnostic radiology department at a government hospital in the Northern Cape, in the absence of published values about this important concept in Republic South Africa.
OBJECTIVES OF THE STUDY
The objectives of this study were:
To calculate the entrance surface air kerma (ESAK) for routine chest X-ray examinations’ postero-anterior (PA) and lateral (LAT) images.
To establish LDRLs for routine chest X-ray examinations (PA and LAT images) at the research site.
To compare LDRLs and the typical dose of chest X-ray examinations with relevant international organisations and values cited in the literature.
To propose changes to the specific research site to optimise and justify patient dose if there are significant differences in LDRLs compared to the values from cited literature.
METHOD
This research study was a cross-sectional study, which is used to examine data at a point in time, that is, the data at/on one occasion only with different participants. It was also a quantitative research study. Quantitative data are numerically measurable, for example, how many, how much or how often. This method determined how much radiation dose a patient receives for each projection. An indirect method was utilised to determine patients’ dose.
The research site was a radiology department in the Northern Cape. Three general radiographic rooms were used, namely, two x-ray rooms equipped with computed radiography (CR) and the third room utilised digital radiography (flat panel detector) [(DR (FPD)].
The methodology was divided into three phases, namely quality control, imaging procedure and ESAK calculation. The quality control was performed by a medical physicist. Radiographers executed the imaging procedure at the research site. The radiographers adhere to the Declaration of Helsinki with regard to ethical standards and behaviour. The radiographers had to obey the International Declaration of Helsinki to select patients, obtain chest X-ray radiographs and data for the research. The data recorded by the radiographers were kilo-voltage peak (kVp), focus film distance (FFD), patients’ weight and patients’ thickness at the centring point. These data were used to determine the ESAK of each projection of the participating patients. The indirect method recommended by International Atomic Energy Agency (IAEA) was used to determine the ESAK. A statistician used a statistical application (SAS version 9.2) to determine the LDRLs for chest X-ray examinations of the three X-ray rooms, radiographic systems and the research site.
The first sixty patients referred for chest X-ray examinations who met the inclusion criteria participated in this study. The patients selected were 18 years and above, accepted to sign the consent form, were referred for chest X-ray examinations, weighed 60 kilograms (kg) to 80 kg and the exposure index of chest X-ray images were within the prescribed manufacturer range.
The ESAK were measured using the indirect method recommended by the IAEA. A statistical application (SAS Version 9.2) was used to determine the LDRLs for chest X-ray examinations of three X-ray rooms, radiographic systems, and the research site.
The instruments that were used for this research were valid because weighing scale measures the weight of a patient in kilograms and a calliper measures the thickness of the patient at the centring point in centimetres (cm). The formula and procedure that were used to estimate dose to patients are recommended by IAEA and other researches have successfully used this formula and procedure to estimate patient dose.
This research study utilised instruments that were reliable. A known weight of 70 kg was placed on the weighing scale. The reading on the weighing scale and the value of the known weight correlated; the weighing scale was deemed reliable. The calliper measurement was compared to a measuring meter. The measurements were the same; the calliper was deemed reliable. Quality assurance (QA) and quality control (QC) were performed on the X-ray machines at regular intervals as per the QA guidelines to ensure the exposure parameters were reliable. The specific tests were: accuracy and reproducibility of kVp, accuracy and reproducibility of exposure time and linearity of the output with milli-ampere (mA) and time.
RESULTS AND DISCUSSION
The following LDRLs for chest X-ray examinations were established; Room 1, postero-anterior projection (PA) (0.3 milli-Gray (mGy) and lateral projection (LAT) (0.8 mGy), Room 2, PA (0.3 mGy) and LAT (0.7 mGy), Room 3, PA (0.2 mGy) and LAT (0.8 mGy), computed radiography (CR), PA (0.3 mGy) and LAT (0.8 mGy), digital radiography (DR), PA (0.2 mGy) and LAT (0.8 mGy) and research site, PA (0.3 mGy) and LAT (0.8 mGy).
The results showed that there were wide ranges for exposure parameters and ESAK for chest examinations at the research site. These wide ranges could be attributed to patients’ weight range and thickness, radiographer skill, knowledge and training and the use of automatic and manual exposure settings. CONCLUSION
The LDRLs for chest X-ray examinations were established at this research site. The LDRLs for chest X-ray examinations were lower than the published international diagnostic reference levels. The recommendation is LDRLs for routine chest X-ray examinations should be repeated after three years according to ICRP. The latest results should then be compared with the results of this research study.
This study did not demonstrate the LDRLs for routine chest X-ray examinations of patients whose weights are less than 60 kg or more than 80 kg. As a result, many patients had to be excluded from this research study because their weight was not within the required weight range of this research study. This is the significant limitation of the research study
The Nature, Prevalence And Perceived Effects Of Sexual Harassment On Girls In Thabo Mofutsanyana District Secondary Schools In The Free State
Get PDFThesisThe study investigated the nature, prevalence and perceived effects of sexual harassment on girls in Thabo Mofutsanyana District secondary schools in the Free State. Secondary school girl leaners are faced with the scourge of sexual harassment in school premises. The focus was to highlight the existence, nature, perpetrators of such acts and the effects that are perceived to exist on affected girl learners in all the five local municipalities in the district. The study is informed by the feminism theory because it deals with gender discrimination. Several gender theories, such as the gender schema theory, social learning theory, social role theory, psychoanalysis theory and cognitive development theory, were explored. The exploration considered gender theories’ impact on how adolescents learn gender roles and stereotypes, and ultimately acting them out in society. The study adopted the mixed methods to gather data. The Sexual Experiences Questionnaire (SEQ) which is a standardised questionnaire was adopted, customised and administered to a sample of 200 girl learners from 26 Thabo Mofutsanyana District secondary schools and interviews were conducted with 5 Thabo Mofutsanyana District officials representing 5 units. The Sexual Experiences Questionnaire revealed the nature and prevalence of sexual harassment while the interviews provided the study with the perceived effects of sexual harassment on girls as opposed to their general wellbeing and their health together with the role that should be played by principals and school governing bodies in curbing sexual harassment in schools. The results confirmed that girl learners are being sexually harassed in secondary schools of Thabo Mofutsanyana District. The study revealed that 96, 2% of the 165 girl participants have been sexually harassed either verbally or in a non – verbal form. These acts are perpetrated by fellow boy learners, educators, principals and parents. The study further revealed that the wellbeing of the victims is negatively affected by these incidents. Principals and SGBs are found wanting in terms of their roles with regards to dealing decisively with sexual harassment in secondary schools. A Sexual Harassment Reporting Model (SHRM) was developed by the researcher and is recommended for use by the Department of Education when dealing with sexual harassment cases. Further studies focussing on the boy learners and the perpetration of sexual harassment at secondary schools of Thabo Mofutsanyana District is recommended
Investigating Alternative Power Generation Strategies For Local Municipalities That Are Tied To The National Grid
Get PDFThe demand for electricity keeps on increasing every year, and this puts pressure on municipalities that are supplying electricity to their communities. Once the demand for electricity goes up, municipalities consume a lot of electricity from national energy suppliers, putting a lot of pressure on the National Grid. Furthermore, some municipalities are struggling to pay off debt owed to national energy suppliers, such as Eskom, due to low revenue collection from electricity, because of non-paying customers, faulty meters and electricity theft. Under this condition, local municipalities may have to consider alternative power generation strategies to continue functioning to a limited degree.
The challenge exists in identifying viable alternative power generation strategies for local municipalities to reduce pressure on the National Grid during the months of high energy demand and to provide limited power to their communities when disconnected from the National Grid, due to load-shedding. The first objective of this research was to conduct an energy audit of two towns in the Free State Province of South Africa, which is Koffiefontein and Petrusburg and correlate it to their electrical bill. Secondly, it was to identify various alternative power generation strategies, based on the energy audit and weather data for the two towns. Thirdly, it was to apply the HOMER simulation tool to evaluate the viability of the proposed strategies and then recommend the most appropriate strategy for the two identified towns. The payback period for the alternative power generation systems was also determined.
The results of the audit indicated that Koffiefontein consists of a total of 2 038 houses, with 1 246 in the township and 792 in town. This town also has 113 businesses, with 36 in the township and 77 in town. Electricity sale statistics from the municipality indicated that Koffiefontein houses consume more electricity than businesses, with June 2016 having the highest electricity consumption of 1 135 572.98 kWh. For Petrusburg, the audit was conducted in town only, as the township is being supplied directly by Eskom. Petrusburg consists of 606 houses and 63 businesses in town. Businesses in Petrusburg town consume more electricity than houses, with August 2016 having the highest electricity consumption of 1 002 048 kWh.
After conducting an energy audit, the HOMER program was used to simulate the output of the two identified potential strategies, which is solar and wind. HOMER indicated that solar energy is the best renewable energy strategy to supplement the current energy source of both Koffiefontein and Petrusburg town, due to it being cost effective and having high yearly energy production. The cost of energy for the battery-based solar PV system, suggested for Koffiefontein houses is R 6.10 /kWh, while the cost of energy for the battery-based wind turbine system is R 776.490 /kWh. For Petrusburg town, the cost of energy for the battery-based solar PV system suggested for Petrusburg businesses is R 4.04 /kWh, while the cost of energy for the battery-based wind turbine system is R 840.4 /kWh. The results revealed that the utilization of a battery-based solar PV system may lead to a payback period of 11.5 years and 7.6 years, for Koffiefontein and Petrusburg respectively.
Municipalities should consider doing an energy audit at least every two years to make sure that they are aware of any energy loses, due to tampered meters and faulty meters so that it can be addressed before it affects revenue collection of the municipality. Towns in the Western Free State should consider installing battery-based solar PV systems for businesses and houses so that they can have access to electricity during load-shedding and reduce the pressure placed on the National Grid during high energy demanding hours. The battery-based wind turbine system is more expensive than the battery-based solar PV system and has a longer payback period. Furthermore, wind speed data collected at Fauresmith indicates that a battery-based wind turbine system would suffer poor performance, due to the low annual wind speed
Extraction Of Cellulose From Agricultural Waste For Water Purification
Get PDFDissertationThe escalating demand for clean water and rising water shortages due to population growth, improper use, and expanding urbanisation have become a global issue. In most parts of the world freshwater contains of contaminants such as heavy metal ions that are detrimental to human health. Water treatment has thus become important for the removal of any contaminants in water to render it safe for consumption. Continuous membrane and/or filter processes have been shown to be effective in water treatment. In this study, agricultural residue in the form of cellulose based maize stalks was used to extract cellulose which is a renewable and environmentally friendly adsorbent material that contains nano- and micro cellulose membranes. The membranes were prepared from cellulose nanofibers and CNT in the absence and presence of sodium lauryl sulfate (SLS) via vacuum filtration process. To Improve the stability and absorption of contaminants, carbon nanotubes were added into the cellulose membranes. Furthermore, to enhance the dispersion of SWCNTs into the cellulose membranes, SLS was used, and the resultant composite was “termed” the modified composites. The membranes were analysed by means of SEM, transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier Transform Infrared spectroscopy (FTIR), UV-vis spectroscopy (UV), and thermogravimetric analysis (TGA). The ratios of the investigated cellulose membranes were categorized as follows: cellulose: non-SLS SWCNT 1:0.3, 1:0.5 and 1:1, as well as: cellulose: CNT: SLS 1:0.3:1, 1:0.5:1 and 1:1:1. SEM and TEM images showed that the presence of sodium lauryl sulfate (SLS) resulted in a better dispersion of the carbon nanotubes within the cellulose matrix with few agglomerates of carbon nanotubes being visible. According to the XRD, the incorporation of carbon nanotubes in the form of single-walled carbon nanotubes (SWCNT) and their modification in the form of SLS seemed to cause little or no change in the peak positions. However, the addition of SWCNTs decreased the crystallinity index of the cellulose i.e. 71.5% to 67.1% for cellulose: CNT 1:0.3. The presence of SLS in the composites was demonstrated by symmetric stretching 2843 cm-1 and asymmetric stretching 2910 cm-1 as became evident using FTIR. Generally, as much as the SLS modified system for cellulose (CNT 1:0.3 composites) showed high removal efficiency, the presence of the SLS-based system seemed to hinder the formation of porous structure in the cellulose membrane and, as a result, reduced the adsorption of the dye. The removal efficiency showed that bromophenol blue dye (46.9%) was most adsorbed by cellulose when compared with dylon dye (2.6%). All investigated samples were found to be resistant to calcium carbonate (CaCO
3), sodium hydroxide (NaOH), and nitric acid (HNO3)
Comparison Of Alkaline Hydrolysis And Newster Sterilizing Alternative Treatment Technologies And Cultural Beliefs On Placenta Management In Gauteng, South Africa
Get PDFThesisThe history and development of a health care risk management legal framework in South Africa has come a long way since the 1500s. A historical overview has shown that continuous development of legal requirements took precedence and that legislative promulgations were typically followed by systems development.
The aim of the study was twofold. First, the study aimed to compare the feasibility of two types of alternative technologies for the treatment of placentas, namely the Alkaline Hydrolysis treatment technology and the NEWster® steriliser system. Various concerns have been raised regarding the operational handling, management, maintenance, and optimal treatment efficiency of these two systems. It was found that the volumes of generated waste in terms of generation versus treatment play a role in the choice of the plant that should be installed. Moreover, based on a comparative evaluation of the two systems, it is evident that the NEWster®, which is the smaller of the two units, is more suitable for small scale operators such as district hospitals, clinics, and community health establishments. This is because the cycle time of the NEWster® is shorter, the space needed to install a unit is less, and the capacity of this unit in terms of generation rates is more in line with international requirements than that of the Alkaline Hydrolysis system.
The second study was to determine the prevalence of traditional beliefs in the management and disposal of placentas. Health professionals were recruited from health establishments in the Department of Health in Gauteng, South Africa. A quantitative investigation was conducted. A questionnaire was used to obtain the required data from health professionals in governmental hospitals in Gauteng. These professionals were selected from five categories, namely matron/nursing supervisor/operational manager, professional nurse, nursing assistant, medical practitioner (doctor), and health care risk waste officer/environmental health practitioner. The envisaged study site would have consisted of the obstetrics and maternity wards of 27 hospitals, but 15 hospitals were ultimately included in the study. The highest district participation rate was from hospitals in the Tshwane district (50.7%), while the lowest participant rate was medical practitioners at 11.11%.
It was determined that the placentas of all the birth mothers (100%) were individually packed in small red plastic bags after giving birth. However, a splash risk was identified.
Differences in timeframes were detected for the placement of placentas after birth into Specicans due to theatre procedures, and this could take up to 30 minutes. The placentas were stored in freezers that were not equipped with a thermometer or mechanism to verify freezer temperatures. There was a 50% chance that a mother who was not aware of the procedures regarding her placenta would request it after it had already been disposed of in a Specican. Moreover, it was evident that health professionals were unsure which procedures to follow should various religious practices associated with a patient’s right to take the placenta home needed to be addressed.
Family members generally collected patients using their own vehicles and it was reported that the placenta would be buried at home as quickly as possible. It is noteworthy that a small percentage of the respondents indicated that placentas would be given to traditional healers.
Taking religion (which is central to the cultural diversity discussion) into account, the most dominant group that tended to take the placentas home was the Indian group. The Zulu population group was the secondary most likely group to take the placenta home. The traditional rituals followed at home were not well defined or described by the participants, which suggests that many Health Professionals may not be aware of customs to dispose of placentas in the traditional manner.
It was also found that there was no standardised record form for placenta handling, and thus a trustworthy data base for placenta management procedures was a challenge. Most of the health professionals (84.13%) had been trained. The study revealed that medical practitioners (i.e., doctors) felt that health care risk waste management was not their responsibility
Industrial Augmented Reality As An Approach For Device Identification Within A Manufacturing Plant For Property Alteration Purposes
Get PDFThesisThe introduction of 3D computer graphics has led to an increase in the processing capacity of the computational units monumentally, along with speed, memory and transmission bandwidth. Augmented Reality (AR) has modelled remarkable progress towards real-world consumer applications. Considering the fact that mass production occurs daily in the manufacturing plants with large sums of wastage, caused either by human error, load-shedding (power outage), machine malfunction, or the time it takes the engineers to identify and fix the problem, are observed in high volumes.
Therefore, the need to identify strategies and solutions to reduce such problems on-site with accurate data, rather than outsourcing or depending solely on the Supervisory Control and Data Acquisition (SCADA) system data, which might damage the integrity and economy of the manufacturing plant, needs to be developed and implemented.
In a controlled network, identification and detection of a component in the process are difficult without prior knowledge and background in the design and implementation process.
Thus, the concept of device identification with the aid of augmented reality, utilising markerless identifiers, such as machine vision, other than Quick Response Codes (QR codes) or Radio Frequency Identification (RFID), needs to be investigated.
It is because of such reasons that the deployment of new types of technologies, such as “augmented reality” and “machine vision” need to further be investigated to obtain the device details, based on their positions and features within the indoor manufacturing plant to procure and commercialise this solution technology.
This study proposes an optimal and efficient model, utilising machine vision application to detect and identify devices, based on their positions and features within the manufacturing plant with the aid of an augmented reality application for extending the device details.
The study has outlined a machine vision application developed for object detection, based on colour and shape. Additionally, another method based on the augmented reality application was developed for the identification and augmentation of device details, based on the feature and position of the device within the indoor manufacturing plant. The study proved to be very successful in the identification and detection of objects, making use of machine vision algorithms, namely colour, shape and Canny Edge detection and the identification of devices (robotic arm and motors), based on their features and position within an indoor manufacturing environment set-up.
For the optimal efficiency of this model, the Simultaneous Localisation and Mapping (SLAM) algorithm (ORB-SLAM) was used, in conjunction with the bundle adjustment algorithm as an alternative solution in the absence of the user built-in maps for the calculation of the device positions, based on the uncertainties of the exact locations within the indoor manufacturing environment set-up.
However, some of the shortcomings were identified and addressed, such as the communication speed and the room’s light conditions, which impacted the sensing of the camera to detect the correct objects. These shortcomings were, however, addressed by conducting two studies, namely the day and night study to compare the best light settings and also to reduce the distance between the devices and the AR application to compensate for the communication speed issues.
The scientific contribution of this study is the recognition of components by means of vision identification within such a process within an indoor manufacturing set-up. By means of identification, the user will have the capability to view and adjust the parameters of the process in a scaled plant. This contribution makes use of a modelled JPEG image. An AR image that the user can identify the devices apart from, relying on the SCADA system alone, was physically modelled on Blender3D for utilisation in Unity3D, as opposed to utilisation of any image and referencing it which would make the process tedious and reduce the processing speed. Subsequently, it has been depicted as part of a new knowledge contribution, that the identification of the devices can be achieved by placing the smartphone at any angle of the device (robotic arm or motor), and the detection and augmentation will be achieved without any change in the settings.
As part of result validation, a video was taken and uploaded on YouTube to receive a user perspective on the developed AR application. After the video upload, a survey was shared with 20 individuals, together with the YouTube link to indicate a broader base evaluation. However, the results came back positive with the majority of the sample individuals recommending the adoption of the application and its utilisation in the scaled manufacturing plant.
In addition to the results verification, a SCADA model was developed in National InstrumentsTM LabviewTM and was integrated with the AR application for evaluation purposes. The results showed that the AR application doesn’t require any alteration, despite utilising a different SCADA model in different software applications, provided that the array index is the same. Only when the array index differs, is it that alterations are necessary utilising the AR application in order to have the same array elements and avoid having a null index that might cause the application to crash or not to debug. It is therefore noted that the AR application is compatible and reliable for integration with other SCADA models without alteration requirements.
The entire work outlined in this thesis was validated by two sets of physical experiments, namely GPS-based detection, and the ORB-SLAM, integrated with the Bundle Adjustment algorithm for feature and position detection. However, despite the prior knowledge of the GPS's inconsistent operation within a scaled indoor environment, it was necessary to perform the test to obtain more insight into this inconsistency and inaccurate data results