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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

An integrated energy efficiency strategy for deep mine ventilation and refrigeration / Abraham Jacobus Schutte

Schutte, Abraham Jacobus January 2014 (has links)
South Africa’s electricity supply is under pressure. Mining is one of South Africa’s largest electricity consumers with electricity-intensive services such as compressed air, cooling, ventilation, etc. More than 40% of mine electricity consumption is used for cooling and ventilation. There is a need to reduce the operational cost on a mine as electricity prices are set to increase at least 2% above South Africa’s inflation target. The mine-cooling and ventilation system was investigated for energy cost-saving. No clear energy and cost-saving strategy for the entire mine-cooling and ventilation system was found. Projects are implemented ad hoc and scattered throughout the system. A strategy is needed to help realise the total saving available on the entire mine-cooling and ventilation system. An implementation strategy for load-management and energy-saving projects on a mine-cooling and ventilation system was developed. A peak clip project on the surface BAC was developed and added to the strategy. The resultant strategy attains all savings throughout the entire mine-cooling and ventilation system. A peak clip project on the surface BAC of a typical mine results in an annual saving of R1.4 million. Implementing this new project on other mines could save R11 million annually. Implementing the sequenced combination of cooperative projects on a typical mine results in a saving of R30 million. That is a saving of 38% on the ventilation and cooling cost and 16% on the total mine electricity bill. / PhD (Mechanical Engineering), North-West University, Potchefstroom Campus, 2014
2

An integrated energy efficiency strategy for deep mine ventilation and refrigeration / Abraham Jacobus Schutte

Schutte, Abraham Jacobus January 2014 (has links)
South Africa’s electricity supply is under pressure. Mining is one of South Africa’s largest electricity consumers with electricity-intensive services such as compressed air, cooling, ventilation, etc. More than 40% of mine electricity consumption is used for cooling and ventilation. There is a need to reduce the operational cost on a mine as electricity prices are set to increase at least 2% above South Africa’s inflation target. The mine-cooling and ventilation system was investigated for energy cost-saving. No clear energy and cost-saving strategy for the entire mine-cooling and ventilation system was found. Projects are implemented ad hoc and scattered throughout the system. A strategy is needed to help realise the total saving available on the entire mine-cooling and ventilation system. An implementation strategy for load-management and energy-saving projects on a mine-cooling and ventilation system was developed. A peak clip project on the surface BAC was developed and added to the strategy. The resultant strategy attains all savings throughout the entire mine-cooling and ventilation system. A peak clip project on the surface BAC of a typical mine results in an annual saving of R1.4 million. Implementing this new project on other mines could save R11 million annually. Implementing the sequenced combination of cooperative projects on a typical mine results in a saving of R30 million. That is a saving of 38% on the ventilation and cooling cost and 16% on the total mine electricity bill. / PhD (Mechanical Engineering), North-West University, Potchefstroom Campus, 2014
3

Assessment of the indoor air quality at the corporate offices of a South African mining company / Marius Meintjes

Meintjes, Marius January 2013 (has links)
Abstract: The aim of the study was to evaluate the indoor air quality (IAQ) of a semi-airtight (the building only utilises mechanical means to ventilate the occupied spaces however an airtight seal is not established as a result of infiltration due to building design) office building that is situated in central Johannesburg that exclusively uses a heating, ventilation and air-conditioning (HVAC) system for ventilation. This implies a system that only utilises mechanical ventilation to heat, cool, humidify and clean the air for comfort, safety and health of employees. This includes the control of odour levels, and also the maintenance of carbon dioxide (CO2) below stipulated levels. Methods: The building is divided into two sections; west and east. Each section has its own ventilation supply. A randomisation process was used to ascertain which offices needed to be sampled, in which section as well as on which floor. For this study, five offices per section were measured. Thus, ten offices per floor were measured and measurements were taken on every second floor. All measurements were done in accordance with the specific requirements of the manufacturer of any specific instrument used and measurements were taken over an eight hour period (full work shift). Results were compared to the available standard, as well as compared to the ambient concentrations. Results: None of the monitored contaminants’ concentration were above the provided standards (ASHRAE or ACGIH). Where standards were unavailable, the HVAC system maintained an indoor contaminant concentration that is substantially lower when compared to the outdoor air concentrations. Conclusion: The buildings’ HVAC system maintains indoor air quality at a healthy level it is unlikely that any one of these contaminants may lead to SBS amongst the employees. / MSc (Occupational Hygiene), North-West University, Potchefstroom Campus, 2014
4

Assessment of the indoor air quality at the corporate offices of a South African mining company / Marius Meintjes

Meintjes, Marius January 2013 (has links)
Abstract: The aim of the study was to evaluate the indoor air quality (IAQ) of a semi-airtight (the building only utilises mechanical means to ventilate the occupied spaces however an airtight seal is not established as a result of infiltration due to building design) office building that is situated in central Johannesburg that exclusively uses a heating, ventilation and air-conditioning (HVAC) system for ventilation. This implies a system that only utilises mechanical ventilation to heat, cool, humidify and clean the air for comfort, safety and health of employees. This includes the control of odour levels, and also the maintenance of carbon dioxide (CO2) below stipulated levels. Methods: The building is divided into two sections; west and east. Each section has its own ventilation supply. A randomisation process was used to ascertain which offices needed to be sampled, in which section as well as on which floor. For this study, five offices per section were measured. Thus, ten offices per floor were measured and measurements were taken on every second floor. All measurements were done in accordance with the specific requirements of the manufacturer of any specific instrument used and measurements were taken over an eight hour period (full work shift). Results were compared to the available standard, as well as compared to the ambient concentrations. Results: None of the monitored contaminants’ concentration were above the provided standards (ASHRAE or ACGIH). Where standards were unavailable, the HVAC system maintained an indoor contaminant concentration that is substantially lower when compared to the outdoor air concentrations. Conclusion: The buildings’ HVAC system maintains indoor air quality at a healthy level it is unlikely that any one of these contaminants may lead to SBS amongst the employees. / MSc (Occupational Hygiene), North-West University, Potchefstroom Campus, 2014
5

The environmental monitoring and quantification of M. tuberculosis occupational exposure risk in various occupational settings in a platinum mine / H.L. Badenhorst

Badenhorst, Hendrik Louis January 2010 (has links)
Tuberculosis is a disease that has a detrimental effect on the economic growth of South Africa. The country’s TB mortality rate is amongst the highest in the world, and the worst affected industry is mining. Effective environmental controls of tuberculosis in mining areas remain a challenge, mainly because there is a lack of quantitative data to guide the implementation of these controls. No occupational exposure limits exist for bio–aerosols, particularly Mycobacterium tuberculosis. This makes it difficult to distinguish between high– and low risk areas. It is believed that a single inhaled M. tuberculosis particle can cause the tuberculosis disease, and as this disease can deteriorate all major systems of the body, great care should be taken in the classification of an area. Aim: This study aimed to quantify the environmental presence of the M. tuberculosis bacilli in various occupational settings of a platinum mine. Method: The monitored areas are all structures above ground, and include high TB risk areas, such as the hospital TB Ward, and low TB risk areas, such as an office area. Personal monitoring of the staff in high TB risk areas has also been conducted. Monitoring was done via the PTFE filter sampling method and the SKC Bio–Sampler impinger method. The results of these two methods were compared to determine which method is more effective. The environmental variables, such as carbon dioxide and -monoxide levels, temperature (both ambient and wet– bulb), and relative humidity, were also monitored in order to identify any possible correlations between these variables and the levels of ambient TB particles. The effectiveness of the Ultraviolet Germicidal Irradiation (UVGI) system, which is in place in some of the monitored areas, was also indirectly assessed, i.e. to see if there are any M. tuberculosis particles present in an area that makes use of an UVGI system. The PCR analytical method was used to quantify the number of M. tuberculosis bacilli sampled, and the results were statistically analysed. Results: M. tuberculosis was found to be present in the office area, the laundry room, the hospital’s waiting area, the training facility, the dining room, and the mobile clinic. No M. tuberculosis particles were found in the hospital’s TB Ward and the change houses of the mine. The results showed that the PTFE filter method had a greater efficiency than the SKC Bio– Sampler in monitoring environmental M. tuberculosis particles, as the PTFE filter method yielded positive samples where the SKC Bio–Sampler did not. There is a practical significant difference between the two methods. No viable correlations between the environmental variables and M. tuberculosis prevalence were established due to the low number of samples taken. Conclusion: It seems that the effectiveness of a UVGI system is dependent on the number of people crowded into that specific area and the ventilation thereof. A UVGI system is only a precautionary measure and not a solution. There are too many factors that still need better understanding before the risk of contracting environmental TB in high risk areas of a mine can be determined. The high risk areas seem to be occupational settings that have poor ventilation, but accommodate a large number of people. The highest risk of TB infection remains close contact with infected individuals, as the results of the employee monitoring testified. / Thesis (M.Sc. (Occupational Hygiene))--North-West University, Potchefstroom Campus, 2011.
6

The environmental monitoring and quantification of M. tuberculosis occupational exposure risk in various occupational settings in a platinum mine / H.L. Badenhorst

Badenhorst, Hendrik Louis January 2010 (has links)
Tuberculosis is a disease that has a detrimental effect on the economic growth of South Africa. The country’s TB mortality rate is amongst the highest in the world, and the worst affected industry is mining. Effective environmental controls of tuberculosis in mining areas remain a challenge, mainly because there is a lack of quantitative data to guide the implementation of these controls. No occupational exposure limits exist for bio–aerosols, particularly Mycobacterium tuberculosis. This makes it difficult to distinguish between high– and low risk areas. It is believed that a single inhaled M. tuberculosis particle can cause the tuberculosis disease, and as this disease can deteriorate all major systems of the body, great care should be taken in the classification of an area. Aim: This study aimed to quantify the environmental presence of the M. tuberculosis bacilli in various occupational settings of a platinum mine. Method: The monitored areas are all structures above ground, and include high TB risk areas, such as the hospital TB Ward, and low TB risk areas, such as an office area. Personal monitoring of the staff in high TB risk areas has also been conducted. Monitoring was done via the PTFE filter sampling method and the SKC Bio–Sampler impinger method. The results of these two methods were compared to determine which method is more effective. The environmental variables, such as carbon dioxide and -monoxide levels, temperature (both ambient and wet– bulb), and relative humidity, were also monitored in order to identify any possible correlations between these variables and the levels of ambient TB particles. The effectiveness of the Ultraviolet Germicidal Irradiation (UVGI) system, which is in place in some of the monitored areas, was also indirectly assessed, i.e. to see if there are any M. tuberculosis particles present in an area that makes use of an UVGI system. The PCR analytical method was used to quantify the number of M. tuberculosis bacilli sampled, and the results were statistically analysed. Results: M. tuberculosis was found to be present in the office area, the laundry room, the hospital’s waiting area, the training facility, the dining room, and the mobile clinic. No M. tuberculosis particles were found in the hospital’s TB Ward and the change houses of the mine. The results showed that the PTFE filter method had a greater efficiency than the SKC Bio– Sampler in monitoring environmental M. tuberculosis particles, as the PTFE filter method yielded positive samples where the SKC Bio–Sampler did not. There is a practical significant difference between the two methods. No viable correlations between the environmental variables and M. tuberculosis prevalence were established due to the low number of samples taken. Conclusion: It seems that the effectiveness of a UVGI system is dependent on the number of people crowded into that specific area and the ventilation thereof. A UVGI system is only a precautionary measure and not a solution. There are too many factors that still need better understanding before the risk of contracting environmental TB in high risk areas of a mine can be determined. The high risk areas seem to be occupational settings that have poor ventilation, but accommodate a large number of people. The highest risk of TB infection remains close contact with infected individuals, as the results of the employee monitoring testified. / Thesis (M.Sc. (Occupational Hygiene))--North-West University, Potchefstroom Campus, 2011.
7

A program to prepare children for grommet insertion and adenoidectomy : a Gestalt therapy approach

Birkenstock, Jeannette Dorothy 30 November 2005 (has links)
The aim of this study was to develop a Gestalt play therapy based hospital preparation program for children undergoing the surgical procedures of grommet insertion, or grommet insertion and adenoidectomy, at Tygerberg Hospital. Literature was reviewed according to relevant topics, namely otitis media in children, Gestalt play therapy, theories of child development, and children's experience of illness and hospitalisation. Semi-structured interviews were conducted with four subject groups and the data obtained was qualitatively analysed. Research findings were discussed and integrated with reference to the literature. This information was applied in the development of the proposed program. The aim, underlying principles, objectives and components of the program were discussed and guidelines for implementation were provided. The program was implemented and evaluated in a single subject pilot study, which yielded a positive response. Recommendations for both practical implementation in a therapeutic context and further study in a research context were made. OPSOMMING Die doel van hierdie studie was om `n Gestalt spelterapie-gebaseerde hospitaalvoorbereidingsprogram te ontwikkel vir kinders wat die chirurgiese prosedures van ventilasiebuis-plasing of ventilasiebuis-plasing en adenoïdektomie by Tygerberg-hospitaal ondergaan. `n Literatuurstudie is uitgevoer rakende relevante onderwerpe; naamlik, otitis media in kinders, Gestalt spelterapie, kinderontwikkelingsteorieë, en kinders se ervaring van siekte en hospitalisasie. Semi-gestruktureerde onderhoude is met vier subjekgroepe uitgevoer en die data wat verkry is, is kwalitatief geanaliseer. Navorsingsbevindinge is bespreek en geïntegreer met verwysing na die literatuur. Hierdie inligting is toegepas in die ontwikkeling van die voorgestelde program. Die doel, onderliggende beginsels, doelstellings en komponente van die program is bespreek en riglyne vir die implementering daarvan is verskaf. Die program is geïmplimenteer en geëvalueer in `n enkelsubjek loodsstudie, waar `n positiewe respons verkry is. Aanbevelings vir beide praktiese implementering in `n terapeutiese konteks en verdere studie binne navorsingskonteks is gemaak. / Social Work / M.Diac.
8

A program to prepare children for grommet insertion and adenoidectomy : a Gestalt therapy approach

Birkenstock, Jeannette Dorothy 30 November 2005 (has links)
The aim of this study was to develop a Gestalt play therapy based hospital preparation program for children undergoing the surgical procedures of grommet insertion, or grommet insertion and adenoidectomy, at Tygerberg Hospital. Literature was reviewed according to relevant topics, namely otitis media in children, Gestalt play therapy, theories of child development, and children's experience of illness and hospitalisation. Semi-structured interviews were conducted with four subject groups and the data obtained was qualitatively analysed. Research findings were discussed and integrated with reference to the literature. This information was applied in the development of the proposed program. The aim, underlying principles, objectives and components of the program were discussed and guidelines for implementation were provided. The program was implemented and evaluated in a single subject pilot study, which yielded a positive response. Recommendations for both practical implementation in a therapeutic context and further study in a research context were made. OPSOMMING Die doel van hierdie studie was om `n Gestalt spelterapie-gebaseerde hospitaalvoorbereidingsprogram te ontwikkel vir kinders wat die chirurgiese prosedures van ventilasiebuis-plasing of ventilasiebuis-plasing en adenoïdektomie by Tygerberg-hospitaal ondergaan. `n Literatuurstudie is uitgevoer rakende relevante onderwerpe; naamlik, otitis media in kinders, Gestalt spelterapie, kinderontwikkelingsteorieë, en kinders se ervaring van siekte en hospitalisasie. Semi-gestruktureerde onderhoude is met vier subjekgroepe uitgevoer en die data wat verkry is, is kwalitatief geanaliseer. Navorsingsbevindinge is bespreek en geïntegreer met verwysing na die literatuur. Hierdie inligting is toegepas in die ontwikkeling van die voorgestelde program. Die doel, onderliggende beginsels, doelstellings en komponente van die program is bespreek en riglyne vir die implementering daarvan is verskaf. Die program is geïmplimenteer en geëvalueer in `n enkelsubjek loodsstudie, waar `n positiewe respons verkry is. Aanbevelings vir beide praktiese implementering in `n terapeutiese konteks en verdere studie binne navorsingskonteks is gemaak. / Social Work / M.Diac.

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