Circular economy ownership models : a view from South Africa industry
- Mativenga, Paul T., Agwa-Ejon, John, Mbohwa, Charles, Sultan, Al Amin Mohamed, Shuaib, Norshah Aizat
- Authors: Mativenga, Paul T. , Agwa-Ejon, John , Mbohwa, Charles , Sultan, Al Amin Mohamed , Shuaib, Norshah Aizat
- Date: 2017
- Subjects: Circular economy ownership models , Composites , Recycling
- Language: English
- Type: Conference proceedings
- Identifier: http://ujcontent.uj.ac.za8080/10210/387361 , http://hdl.handle.net/10210/248487 , uj:25828 , Citation: Mativenga, P.T. et al. 2017. Circular economy ownership models : a view from South Africa industry. Procedia Manufacturing, 8:284-291. 14th Global Conference on Sustainable Manufacturing, GCSM 3-5 October 2016, Stellenbosch, South Africa. doi: 10.1016/j.promfg.2017.02.036 , ISSN: 2351-9789
- Description: Abstract: The world is neither globally successful in remanufacturing and re-use of products nor recycling of waste materials. This requires a combination of circular economy management systems, business models and novel technologies. There are contrasting views in literature regarding models for a circular economy. The main views are built on extended producer responsibility and on the role of end users. This paper is based on a study of the South African industry’s view of circular economy models, drivers and sustainers, with particular focus on composite waste. Cost reduction was found to be the strongest driver and sustainer for recycling of composites. Thus, maximizing opportunities to reduce cost is a key factor in encouraging South African companies to embrace the circular economy. This is important in developing appropriate national models for managing the transition to a circular economy.
- Full Text:
- Authors: Mativenga, Paul T. , Agwa-Ejon, John , Mbohwa, Charles , Sultan, Al Amin Mohamed , Shuaib, Norshah Aizat
- Date: 2017
- Subjects: Circular economy ownership models , Composites , Recycling
- Language: English
- Type: Conference proceedings
- Identifier: http://ujcontent.uj.ac.za8080/10210/387361 , http://hdl.handle.net/10210/248487 , uj:25828 , Citation: Mativenga, P.T. et al. 2017. Circular economy ownership models : a view from South Africa industry. Procedia Manufacturing, 8:284-291. 14th Global Conference on Sustainable Manufacturing, GCSM 3-5 October 2016, Stellenbosch, South Africa. doi: 10.1016/j.promfg.2017.02.036 , ISSN: 2351-9789
- Description: Abstract: The world is neither globally successful in remanufacturing and re-use of products nor recycling of waste materials. This requires a combination of circular economy management systems, business models and novel technologies. There are contrasting views in literature regarding models for a circular economy. The main views are built on extended producer responsibility and on the role of end users. This paper is based on a study of the South African industry’s view of circular economy models, drivers and sustainers, with particular focus on composite waste. Cost reduction was found to be the strongest driver and sustainer for recycling of composites. Thus, maximizing opportunities to reduce cost is a key factor in encouraging South African companies to embrace the circular economy. This is important in developing appropriate national models for managing the transition to a circular economy.
- Full Text:
Design of a 10-digit inventory codification system for a tube and pipe manufacturing company in Zimbabwe
- Nyemba, Wilson R., Mbohwa, Charles
- Authors: Nyemba, Wilson R. , Mbohwa, Charles
- Date: 2017
- Subjects: Inventory control , Manufacturing , Maintenance
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/224997 , uj:22714 , Citation: Nyemba, W.R. & Mbohwa, C. 2017. Design of a 10-digit inventory codification system for a tube and pipe manufacturing company in Zimbabwe. 14th Global Conference on Sustainable Manufacturing, GCSM 3-5 October 2016, Stellenbosch, South Africa. DOI: 10.1016/j.promfg.2017.02.064. , ISSN: 2351-9789
- Description: Abstract: Lack of proper inventory control usually leads to high stock-outs resulting in ‘firefighting’. This paper looks at the engineering and technical services required to maintain smooth production with the aim of developing an inventory control system for the efficient utilization of resources. A work study was carried out at a tube and pipe manufacturing company in Zimbabwe followed by an analysis outlining the operations, limitations and process flows. An inventory audit provided some insights on the company’s inventory control status. A 10-digit inventory codification system was designed based on 7 rules for generic application and capability for ‘make or buy’ decisions on spare parts. A cost benefit analysis revealed that although the project would initially be costly, a reduction in inventory can be realized through removal of slow moving and obsolete stock, realizing some annual savings in the long run, coupled with an improvement in record keeping and accountability.Lack of proper inventory control usually leads to high stock-outs resulting in ‘firefighting’. This paper looks at the engineering and technical services required to maintain smooth production with the aim of developing an inventory control system for the efficient utilization of resources. A work study was carried out at a tube and pipe manufacturing company in Zimbabwe followed by an analysis outlining the operations, limitations and process flows. An inventory audit provided some insights on the company’s inventory control status. A 10-digit inventory codification system was designed based on 7 rules for generic application and capability for ‘make or buy’ decisions on spare parts. A cost benefit analysis revealed that although the project would initially be costly, a reduction in inventory can be realized through removal of slow moving and obsolete stock, realizing some annual savings in the long run, coupled with an improvement in record keeping and accountability.
- Full Text:
- Authors: Nyemba, Wilson R. , Mbohwa, Charles
- Date: 2017
- Subjects: Inventory control , Manufacturing , Maintenance
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/224997 , uj:22714 , Citation: Nyemba, W.R. & Mbohwa, C. 2017. Design of a 10-digit inventory codification system for a tube and pipe manufacturing company in Zimbabwe. 14th Global Conference on Sustainable Manufacturing, GCSM 3-5 October 2016, Stellenbosch, South Africa. DOI: 10.1016/j.promfg.2017.02.064. , ISSN: 2351-9789
- Description: Abstract: Lack of proper inventory control usually leads to high stock-outs resulting in ‘firefighting’. This paper looks at the engineering and technical services required to maintain smooth production with the aim of developing an inventory control system for the efficient utilization of resources. A work study was carried out at a tube and pipe manufacturing company in Zimbabwe followed by an analysis outlining the operations, limitations and process flows. An inventory audit provided some insights on the company’s inventory control status. A 10-digit inventory codification system was designed based on 7 rules for generic application and capability for ‘make or buy’ decisions on spare parts. A cost benefit analysis revealed that although the project would initially be costly, a reduction in inventory can be realized through removal of slow moving and obsolete stock, realizing some annual savings in the long run, coupled with an improvement in record keeping and accountability.Lack of proper inventory control usually leads to high stock-outs resulting in ‘firefighting’. This paper looks at the engineering and technical services required to maintain smooth production with the aim of developing an inventory control system for the efficient utilization of resources. A work study was carried out at a tube and pipe manufacturing company in Zimbabwe followed by an analysis outlining the operations, limitations and process flows. An inventory audit provided some insights on the company’s inventory control status. A 10-digit inventory codification system was designed based on 7 rules for generic application and capability for ‘make or buy’ decisions on spare parts. A cost benefit analysis revealed that although the project would initially be costly, a reduction in inventory can be realized through removal of slow moving and obsolete stock, realizing some annual savings in the long run, coupled with an improvement in record keeping and accountability.
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Equipment maintenance challenges and solutions for capacity building and sustainability in the training of engineers : the case for the University of Zimbabwe
- Nyemba, Wilson R., Mashamba, Able, Mbohwa, Charles
- Authors: Nyemba, Wilson R. , Mashamba, Able , Mbohwa, Charles
- Date: 2016
- Subjects: Industrial capacity , Engineering equipment - Maintenance and repair , Engineers - Training of - Zimbabwe
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/223373 , uj:22459 , Citation: Nyemba, W.R., Mashamba, A. & Mbohwa, C. 2016. Equipment maintenance challenges and solutions for capacity building and sustainability in the training of engineers : the case for the University of Zimbabwe. International Conference on Sustainable Materials Processing and Manufacturing, SMPM 2017, 23-25 January 2017, Kruger National Park. , ISSN: 2351-9789
- Description: Abstract: Engineering equipment in some Higher Education Institutions (HEIs) in Sub-Saharan Africa is underutilized, obsolete or in poor working condition owing to lack of expertise, aging or maintenance-related challenges respectively. A research initiated by the Network of Users of Scientific Equipment in Eastern and Southern Africa (NUSESA) and funded by the Swedish International Development Cooperation Agency (Sida) was carried out by 4 faculties of engineering in Southern Africa to establish common challenges, their causes and to propose solutions. The study revealed that the faculties shared similar problems such as no proper maintenance documentation, no local suppliers for spares and inadequate expertise. The importation of spares usually leads to prolonged lead times and delays in timely repairs to malfunctioning equipment and thus obsolescence. This paper proposes smart procurement partnerships between industry and HEIs, based on the findings from the University of Zimbabwe (UZ). Following the survey and analysis of data obtained, recommendations were made and implemented and have assisted in building capacity in acquisition, maintenance and management of laboratory equipment and sustaining these in the training of engineers.
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- Authors: Nyemba, Wilson R. , Mashamba, Able , Mbohwa, Charles
- Date: 2016
- Subjects: Industrial capacity , Engineering equipment - Maintenance and repair , Engineers - Training of - Zimbabwe
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/223373 , uj:22459 , Citation: Nyemba, W.R., Mashamba, A. & Mbohwa, C. 2016. Equipment maintenance challenges and solutions for capacity building and sustainability in the training of engineers : the case for the University of Zimbabwe. International Conference on Sustainable Materials Processing and Manufacturing, SMPM 2017, 23-25 January 2017, Kruger National Park. , ISSN: 2351-9789
- Description: Abstract: Engineering equipment in some Higher Education Institutions (HEIs) in Sub-Saharan Africa is underutilized, obsolete or in poor working condition owing to lack of expertise, aging or maintenance-related challenges respectively. A research initiated by the Network of Users of Scientific Equipment in Eastern and Southern Africa (NUSESA) and funded by the Swedish International Development Cooperation Agency (Sida) was carried out by 4 faculties of engineering in Southern Africa to establish common challenges, their causes and to propose solutions. The study revealed that the faculties shared similar problems such as no proper maintenance documentation, no local suppliers for spares and inadequate expertise. The importation of spares usually leads to prolonged lead times and delays in timely repairs to malfunctioning equipment and thus obsolescence. This paper proposes smart procurement partnerships between industry and HEIs, based on the findings from the University of Zimbabwe (UZ). Following the survey and analysis of data obtained, recommendations were made and implemented and have assisted in building capacity in acquisition, maintenance and management of laboratory equipment and sustaining these in the training of engineers.
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Experimental investigation of ceramic substrates in standing wave thermoacoustic refrigerator
- Alcock, A. C., Tartibu, L. K., Jen, T. C.
- Authors: Alcock, A. C. , Tartibu, L. K. , Jen, T. C.
- Date: 2016
- Subjects: Thermoacoustic , Refrigeration , Ceramic substrates
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/223682 , uj:22499 , Citation: Alcock, A.C., Tartibu, L.K. & Jen, T.C. 2016. Experimental investigation of ceramic substrates in standing wave thermoacoustic refrigerator. International Conference on Sustainable Materials Processing and Manufacturing, SMPM 2017, 23-25 January 2017, Kruger National Park. DOI: 10.1016/j.promfg.2016.12.021. , ISSN: 2351-9789
- Description: Abstract: This work experimentally investigates the performance of ceramic substrates used as stacks in standing wave thermoacoustic coolers. Thermoacoustic technology is proposed in this study as an alternative sustainable solution to current issues with vapour compression refrigerators because of its environmentally friendlier attributes. However, the main hindrance to the expansion of this technology is its current lack of efficiency. Hence, an experimental investigation is conducted in this study. The influence of the geometrical configuration of the stack, described as the heart of the device, is investigated. The device was equipped with different selected low-cost porous materials (ceramic substrates) for performance testing and studies. Porosity, length and position of the ceramic substrates are variables that are considered in order to investigate the performance of the cooler. Eight cordierite honeycomb ceramic substrates with square cross sections and of four different lengths (26 mm, 48 mm, 70 mm and 100 mm) were considered. Five different stack positions, measured from the hot ends of the stack to the pressure antinode in increments of 100 mm, were investigated. Measurement of temperature difference at steady state was used to determine the performance of a particular configuration. Guidance on the design of this sustainable solution for refrigeration and selection of the best geometrical configuration of ceramic substrates are provided. In addition, clarity on the relation between the geometrical configurations and the frequencies of the sound wave is highlighted.
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- Authors: Alcock, A. C. , Tartibu, L. K. , Jen, T. C.
- Date: 2016
- Subjects: Thermoacoustic , Refrigeration , Ceramic substrates
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/223682 , uj:22499 , Citation: Alcock, A.C., Tartibu, L.K. & Jen, T.C. 2016. Experimental investigation of ceramic substrates in standing wave thermoacoustic refrigerator. International Conference on Sustainable Materials Processing and Manufacturing, SMPM 2017, 23-25 January 2017, Kruger National Park. DOI: 10.1016/j.promfg.2016.12.021. , ISSN: 2351-9789
- Description: Abstract: This work experimentally investigates the performance of ceramic substrates used as stacks in standing wave thermoacoustic coolers. Thermoacoustic technology is proposed in this study as an alternative sustainable solution to current issues with vapour compression refrigerators because of its environmentally friendlier attributes. However, the main hindrance to the expansion of this technology is its current lack of efficiency. Hence, an experimental investigation is conducted in this study. The influence of the geometrical configuration of the stack, described as the heart of the device, is investigated. The device was equipped with different selected low-cost porous materials (ceramic substrates) for performance testing and studies. Porosity, length and position of the ceramic substrates are variables that are considered in order to investigate the performance of the cooler. Eight cordierite honeycomb ceramic substrates with square cross sections and of four different lengths (26 mm, 48 mm, 70 mm and 100 mm) were considered. Five different stack positions, measured from the hot ends of the stack to the pressure antinode in increments of 100 mm, were investigated. Measurement of temperature difference at steady state was used to determine the performance of a particular configuration. Guidance on the design of this sustainable solution for refrigeration and selection of the best geometrical configuration of ceramic substrates are provided. In addition, clarity on the relation between the geometrical configurations and the frequencies of the sound wave is highlighted.
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Investigation of the parameters governing the performance of jet impingement quick food freezing and cooling systems – a review
- Marazani, Tawanda, Madyira, Daniel M., Akinlabi, Esther Titilayo
- Authors: Marazani, Tawanda , Madyira, Daniel M. , Akinlabi, Esther Titilayo
- Date: 2017
- Subjects: Jet impingement , food , freezing
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/247095 , uj:25648 , Citation: Marazani, T., Madyira, D.M. & Akinlabi, E.T. 2017. Investigation of the parameters governing the performance of jet impingement quick food freezing and cooling systems – a review. Procedia Manufacturing 8:754–760. 14th Global Conference on Sustainable Manufacturing, GCSM 3-5 October 2016, Stellenbosch, South Africa. doi: 10.1016/j.promfg.2017.02.097 , ISSN: 2351-9789
- Description: Abstract: Jet Impingement Technology (JIT) is a heat transfer enhancement technique. Available literature soundly confirm its wide applications in the cooling of combustion chambers, critical parts of turbines, glass technology, electronic components, drying of paper and textile materials, drying of biomaterials and food preservation. The technology has interesting fluid dynamics and heat transfer properties. Its relative simplicity and low cost, abundance of air, generation of high heat transfer and faster freezing rates have made it a subject of extensive investigations. Several investigations on jet impingement quick food freezing and cooling systems which range from visualization, experimental, computational simulations and or numerical analysis, factorial and mathematical models have been studied. This paper reviews the governing parameters of the jet impingement quick food freezing and cooling systems.
- Full Text:
- Authors: Marazani, Tawanda , Madyira, Daniel M. , Akinlabi, Esther Titilayo
- Date: 2017
- Subjects: Jet impingement , food , freezing
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/247095 , uj:25648 , Citation: Marazani, T., Madyira, D.M. & Akinlabi, E.T. 2017. Investigation of the parameters governing the performance of jet impingement quick food freezing and cooling systems – a review. Procedia Manufacturing 8:754–760. 14th Global Conference on Sustainable Manufacturing, GCSM 3-5 October 2016, Stellenbosch, South Africa. doi: 10.1016/j.promfg.2017.02.097 , ISSN: 2351-9789
- Description: Abstract: Jet Impingement Technology (JIT) is a heat transfer enhancement technique. Available literature soundly confirm its wide applications in the cooling of combustion chambers, critical parts of turbines, glass technology, electronic components, drying of paper and textile materials, drying of biomaterials and food preservation. The technology has interesting fluid dynamics and heat transfer properties. Its relative simplicity and low cost, abundance of air, generation of high heat transfer and faster freezing rates have made it a subject of extensive investigations. Several investigations on jet impingement quick food freezing and cooling systems which range from visualization, experimental, computational simulations and or numerical analysis, factorial and mathematical models have been studied. This paper reviews the governing parameters of the jet impingement quick food freezing and cooling systems.
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Modelling, simulation and optimization of the materials flow of a multi-product assembling plant
- Nyemba, Wilson R., Mbohwa, Charles
- Authors: Nyemba, Wilson R. , Mbohwa, Charles
- Date: 2017
- Subjects: Arena® , Materials flow , Modelling
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/225005 , uj:22715 , Citation: Nyemba, W.R. & Mbohwa, C. 2017. Modelling, simulation and optimization of the materials flow of a multi-product assembling plant. 14th Global Conference on Sustainable Manufacturing, GCSM 3-5 October 2016, Stellenbosch, South Africa. DOI: 10.1016/j.promfg.2017.02.007. , ISSN: 2351-9789
- Description: Abstract: Various dynamic factors impact the movement of materials within a manufacturing environment, increasingly becoming complex for multi-product assembling plants owing to the multiplicity and interconnectedness of these factors. Analyzing these factors can be equally complex, requiring modelling and simulation tools. This paper looks at the modelling and simulation of the materials flow of a multi-product furniture assembling plant to develop an efficient system that accomplishes timely product deliveries at minimal cost. Generic simulation models based on 2 products were developed and constructed using Arena® Simulation Software. Following the simulation experiments and implementation of the results, the average hourly throughput was significantly increased and additional space to store materials prior to processing at workstations was created. The generic models were compatible with the company's other products and hence useful for the company’s production planning and scheduling.
- Full Text:
- Authors: Nyemba, Wilson R. , Mbohwa, Charles
- Date: 2017
- Subjects: Arena® , Materials flow , Modelling
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/225005 , uj:22715 , Citation: Nyemba, W.R. & Mbohwa, C. 2017. Modelling, simulation and optimization of the materials flow of a multi-product assembling plant. 14th Global Conference on Sustainable Manufacturing, GCSM 3-5 October 2016, Stellenbosch, South Africa. DOI: 10.1016/j.promfg.2017.02.007. , ISSN: 2351-9789
- Description: Abstract: Various dynamic factors impact the movement of materials within a manufacturing environment, increasingly becoming complex for multi-product assembling plants owing to the multiplicity and interconnectedness of these factors. Analyzing these factors can be equally complex, requiring modelling and simulation tools. This paper looks at the modelling and simulation of the materials flow of a multi-product furniture assembling plant to develop an efficient system that accomplishes timely product deliveries at minimal cost. Generic simulation models based on 2 products were developed and constructed using Arena® Simulation Software. Following the simulation experiments and implementation of the results, the average hourly throughput was significantly increased and additional space to store materials prior to processing at workstations was created. The generic models were compatible with the company's other products and hence useful for the company’s production planning and scheduling.
- Full Text:
Performance evaluation of ceramic substrates for cooling applications in thermo-acoustic refrigerators
- Balonji, S., Tartibu, L. K., Jen, T. C.
- Authors: Balonji, S. , Tartibu, L. K. , Jen, T. C.
- Date: 2016
- Subjects: Thermo-acoustic , DeltaEc , Ceramic substrate
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/223689 , uj:22500 , Citation: Balonji, S., Tartibu, L.K. & Jen, T.C. 2016. Performance evaluation of ceramic substrates for cooling applications in thermo-acoustic refrigerators. International Conference on Sustainable Materials Processing and Manufacturing, SMPM 2017, 23-25 January 2017, Kruger National Park. DOI: 10.1016/j.promfg.2016.12.035. , ISSN: 2351-9789
- Description: Abstract: Thermo-acoustic refrigerators have recently drawn more attentions because of its eco-friendlier potential to address the current environmental issues resulting from the use of traditional vapour compression refrigerators. This paper aims at evaluating different selected ceramic substrates, with square pores, from the point of view of their performance as stack materials in the design of thermo-acoustic standing wave refrigerators. A 465 mm standing wave thermo-acoustic refrigerator was designed using numerical approximation provided by a modeling code called DELTAEC (Design Environment for Low-amplitude ThermoAcoustic Energy Conversion). The design developed focuses, in particular, on the effects of different ceramic substrate configurations (diameter, length, porosity and position) on the performance of the device. Meaningful comparison on the effect of the ceramic substrates configuration is provided in order to assess the performance of the device. Guidance on the identification and the selection of the best geometrical configurations of ceramic substrates are the main contributions of this work.
- Full Text:
- Authors: Balonji, S. , Tartibu, L. K. , Jen, T. C.
- Date: 2016
- Subjects: Thermo-acoustic , DeltaEc , Ceramic substrate
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/223689 , uj:22500 , Citation: Balonji, S., Tartibu, L.K. & Jen, T.C. 2016. Performance evaluation of ceramic substrates for cooling applications in thermo-acoustic refrigerators. International Conference on Sustainable Materials Processing and Manufacturing, SMPM 2017, 23-25 January 2017, Kruger National Park. DOI: 10.1016/j.promfg.2016.12.035. , ISSN: 2351-9789
- Description: Abstract: Thermo-acoustic refrigerators have recently drawn more attentions because of its eco-friendlier potential to address the current environmental issues resulting from the use of traditional vapour compression refrigerators. This paper aims at evaluating different selected ceramic substrates, with square pores, from the point of view of their performance as stack materials in the design of thermo-acoustic standing wave refrigerators. A 465 mm standing wave thermo-acoustic refrigerator was designed using numerical approximation provided by a modeling code called DELTAEC (Design Environment for Low-amplitude ThermoAcoustic Energy Conversion). The design developed focuses, in particular, on the effects of different ceramic substrate configurations (diameter, length, porosity and position) on the performance of the device. Meaningful comparison on the effect of the ceramic substrates configuration is provided in order to assess the performance of the device. Guidance on the identification and the selection of the best geometrical configurations of ceramic substrates are the main contributions of this work.
- Full Text:
Process evaluation of a domestic biogas digester
- Authors: Madushela, Nkosinathi
- Date: 2017
- Subjects: Biogas digesters , Life Cycle Assessment
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/218682 , uj:21807 , Citation: Madushela, N. 2017. Process evaluation of a domestic biogas digester. International Conference on Sustainable Materials Processing and Manufacturing, SMPM 2017, 23-25 January 2017, Kruger National Park. , ISSN: 2351-9789
- Description: Abstract: Africa has launched a Life Cycle Assessment (LCA) network in conjunction with the Society of Environment Toxicology and Chemistry (SETAC), and this points to a recognized gap in LCA initiatives between developed and developing countries. Although South Africa does not have legislation on carrying-out LCA initiatives, there is a huge drive on preserving our environment, and that is evidenced through the carbon tax bill already proposed. It is due to such developments that the authors initiated an LCA initiative in the design phase of a Biogas Plant for domestic applications. Thorough LCA initiatives are notorious for being time consuming and often manipulated by organizations to “greenwash” their products. These challenges have been a stumbling block for the acceptance of LCA initiatives. The paper looked at the operation of a biogas digester process, for a biogas digester that has been developed in the University of Johannesburg. From the aforementioned process fundamental Life Cycle computation was carried out to identify the environmental impact of the product.
- Full Text:
- Authors: Madushela, Nkosinathi
- Date: 2017
- Subjects: Biogas digesters , Life Cycle Assessment
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/218682 , uj:21807 , Citation: Madushela, N. 2017. Process evaluation of a domestic biogas digester. International Conference on Sustainable Materials Processing and Manufacturing, SMPM 2017, 23-25 January 2017, Kruger National Park. , ISSN: 2351-9789
- Description: Abstract: Africa has launched a Life Cycle Assessment (LCA) network in conjunction with the Society of Environment Toxicology and Chemistry (SETAC), and this points to a recognized gap in LCA initiatives between developed and developing countries. Although South Africa does not have legislation on carrying-out LCA initiatives, there is a huge drive on preserving our environment, and that is evidenced through the carbon tax bill already proposed. It is due to such developments that the authors initiated an LCA initiative in the design phase of a Biogas Plant for domestic applications. Thorough LCA initiatives are notorious for being time consuming and often manipulated by organizations to “greenwash” their products. These challenges have been a stumbling block for the acceptance of LCA initiatives. The paper looked at the operation of a biogas digester process, for a biogas digester that has been developed in the University of Johannesburg. From the aforementioned process fundamental Life Cycle computation was carried out to identify the environmental impact of the product.
- Full Text:
Repair of cracks in metals : a review
- Marazani, Tawanda, Madyira, Daniel M., Akinlabi, Esther Titilayo
- Authors: Marazani, Tawanda , Madyira, Daniel M. , Akinlabi, Esther Titilayo
- Date: 2017
- Subjects: Cracks , Crack repair techniques , Metals
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/247138 , uj:25656 , ISSN: 2351-9789 , Citation: Marazani, T., Madyira, D.M. & Akinlabi, E.T. 2017. Repair of cracks in metals : a review. Procedia Manufacturing 8:673-679. 14th Global Conference on Sustainable Manufacturing, GCSM 3-5 October 2016, Stellenbosch, South Africa. doi: 10.1016/j.promfg.2017.02.086
- Description: Abstract: Cracks are surface or subsurface fissures that develop in a material. Propagation energy derived from mechanical, thermal, chemical, and metallurgical effects, or a combination of these may influence crack initiation and growth. Various types of cracks exist in metals and can be categorised as cooling, solidification, centreline, crater, grinding, pickling, heat treatment, machining tears, plating, fatigue, creep, stress corrosion and hydrogen cracks. Cracks can grow and lead to complete fracture of the component posing significant threats to component life and may lead to serious injuries or loss of life. Brittle fracture in metals occurs with little or no visible warning. Discovery of any cracks warrants immediate interventions to arrest the cracks before they propagate to the point of fracture. Several crack detection and repair methods in metals have been developed, characterised and validated through research. This paper reviews the repair techniques of cracks in metals.
- Full Text:
- Authors: Marazani, Tawanda , Madyira, Daniel M. , Akinlabi, Esther Titilayo
- Date: 2017
- Subjects: Cracks , Crack repair techniques , Metals
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/247138 , uj:25656 , ISSN: 2351-9789 , Citation: Marazani, T., Madyira, D.M. & Akinlabi, E.T. 2017. Repair of cracks in metals : a review. Procedia Manufacturing 8:673-679. 14th Global Conference on Sustainable Manufacturing, GCSM 3-5 October 2016, Stellenbosch, South Africa. doi: 10.1016/j.promfg.2017.02.086
- Description: Abstract: Cracks are surface or subsurface fissures that develop in a material. Propagation energy derived from mechanical, thermal, chemical, and metallurgical effects, or a combination of these may influence crack initiation and growth. Various types of cracks exist in metals and can be categorised as cooling, solidification, centreline, crater, grinding, pickling, heat treatment, machining tears, plating, fatigue, creep, stress corrosion and hydrogen cracks. Cracks can grow and lead to complete fracture of the component posing significant threats to component life and may lead to serious injuries or loss of life. Brittle fracture in metals occurs with little or no visible warning. Discovery of any cracks warrants immediate interventions to arrest the cracks before they propagate to the point of fracture. Several crack detection and repair methods in metals have been developed, characterised and validated through research. This paper reviews the repair techniques of cracks in metals.
- Full Text:
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