Absorption of volatile organic compounds into polydimethylsiloxane : phase equilibrium computation at infinite dilution
- Muzenda, Edison, Mateescu, Corina M.
- Authors: Muzenda, Edison , Mateescu, Corina M.
- Date: 2011
- Subjects: Volatile organic compounds , Polydimethylsiloxane , UNIFAC group contribution methods
- Type: Article
- Identifier: uj:5318 , ISSN 2010-3778 , http://hdl.handle.net/10210/8183
- Description: Group contribution methods such as the UNIFAC are very useful to researchers and engineers involved in synthesis, feasibility studies, design and optimization of separation processes. They can be applied successfully to predict phase equilibrium and excess properties in the development of chemical and separation processes. The main focus of this work was to investigate the possibility of absorbing selected volatile organic compounds (VOCs) into polydimethylsiloxane (PDMS) using three selected UNIFAC group contribution methods. Absorption followed by subsequent stripping is the predominant available abatement technology of VOCs from flue gases prior to their release into the atmosphere. The original, modified and effective UNIFAC models were used in this work. The thirteen selected VOCs that have been considered in this research are: pentane, hexane, heptanes, trimethylamine, toluene, xylene, cyclohexane, butyl acetate, diethyl acetate, chloroform, acetone, ethyl methyl ketone and isobutyl methyl ketone. The computation was done for solute VOC concentration of 8.55x10-8 which is well in the infinite dilution region. The results obtained in this study compare very well with those published in literature obtained through both measurements and predictions. The phase equilibrium obtained in this study show that PDMS is a good absorbent for the removal of VOCs from contaminated air streams through physical absorption.
- Full Text:
- Authors: Muzenda, Edison , Mateescu, Corina M.
- Date: 2011
- Subjects: Volatile organic compounds , Polydimethylsiloxane , UNIFAC group contribution methods
- Type: Article
- Identifier: uj:5318 , ISSN 2010-3778 , http://hdl.handle.net/10210/8183
- Description: Group contribution methods such as the UNIFAC are very useful to researchers and engineers involved in synthesis, feasibility studies, design and optimization of separation processes. They can be applied successfully to predict phase equilibrium and excess properties in the development of chemical and separation processes. The main focus of this work was to investigate the possibility of absorbing selected volatile organic compounds (VOCs) into polydimethylsiloxane (PDMS) using three selected UNIFAC group contribution methods. Absorption followed by subsequent stripping is the predominant available abatement technology of VOCs from flue gases prior to their release into the atmosphere. The original, modified and effective UNIFAC models were used in this work. The thirteen selected VOCs that have been considered in this research are: pentane, hexane, heptanes, trimethylamine, toluene, xylene, cyclohexane, butyl acetate, diethyl acetate, chloroform, acetone, ethyl methyl ketone and isobutyl methyl ketone. The computation was done for solute VOC concentration of 8.55x10-8 which is well in the infinite dilution region. The results obtained in this study compare very well with those published in literature obtained through both measurements and predictions. The phase equilibrium obtained in this study show that PDMS is a good absorbent for the removal of VOCs from contaminated air streams through physical absorption.
- Full Text:
Design of an innovative accelerant detector
- Akinlabi, Esther Titilayo, Akinlabi, Stephen A., Isvarial, Milan
- Authors: Akinlabi, Esther Titilayo , Akinlabi, Stephen A. , Isvarial, Milan
- Date: 2012
- Subjects: Accelerant detectors
- Type: Article
- Identifier: uj:5338 , ISSN 2010-3778 , http://hdl.handle.net/10210/8898
- Description: Today, canines are still used effectively in acceleration detection situation. However, this method is becoming impractical in modern age and a new automated replacement to the canine is required. This paper reports the design of an innovative accelerant detector. Designing an accelerant detector is a long process as is any design process; therefore, a solution to the need for a mobile, effective accelerant detector is hereby presented. The device is simple and efficient to ensure that any accelerant detection can be conducted quickly and easily. The design utilizes Ultra Violet (UV) light to detect the accelerant. When the UV light shines on an accelerant, the hydrocarbons in the accelerant emit florescence. The advantages of using the UV light to detect accelerant are also outlined in this paper. The mobility of the device is achieved by using a Direct Current (DC) motor to run tank tracks. Tank tracks were chosen as to ensure that the device will be mobile in the rough terrain of a fire site. The materials selected for the various parts are also presented. A Solid Works Simulation was also conducted on the stresses in the shafts and the results are presented. This design is an innovative solution which offers a user friendly interface. The design is also environmentally friendly, ecologically sound and safe to use.
- Full Text:
- Authors: Akinlabi, Esther Titilayo , Akinlabi, Stephen A. , Isvarial, Milan
- Date: 2012
- Subjects: Accelerant detectors
- Type: Article
- Identifier: uj:5338 , ISSN 2010-3778 , http://hdl.handle.net/10210/8898
- Description: Today, canines are still used effectively in acceleration detection situation. However, this method is becoming impractical in modern age and a new automated replacement to the canine is required. This paper reports the design of an innovative accelerant detector. Designing an accelerant detector is a long process as is any design process; therefore, a solution to the need for a mobile, effective accelerant detector is hereby presented. The device is simple and efficient to ensure that any accelerant detection can be conducted quickly and easily. The design utilizes Ultra Violet (UV) light to detect the accelerant. When the UV light shines on an accelerant, the hydrocarbons in the accelerant emit florescence. The advantages of using the UV light to detect accelerant are also outlined in this paper. The mobility of the device is achieved by using a Direct Current (DC) motor to run tank tracks. Tank tracks were chosen as to ensure that the device will be mobile in the rough terrain of a fire site. The materials selected for the various parts are also presented. A Solid Works Simulation was also conducted on the stresses in the shafts and the results are presented. This design is an innovative solution which offers a user friendly interface. The design is also environmentally friendly, ecologically sound and safe to use.
- Full Text:
Effect of scanning speed on material efficiency of laser metal deposited Ti6Al4V
- Akinlabi, Esther Titilayo, Mahamood, Rasheedat M., Shukla, Mukul, Pityana, Sisa
- Authors: Akinlabi, Esther Titilayo , Mahamood, Rasheedat M. , Shukla, Mukul , Pityana, Sisa
- Date: 2012
- Subjects: Laser Metal Deposition Process , Material efficiency , Titanium alloy , Laser scanning speed
- Type: Article
- Identifier: uj:5337 , ISSN 2010-3778 , http://hdl.handle.net/10210/8880
- Description: The study of effect of laser scanning speed on material efficiency in Ti6Al4V application is very important because unspent powder is not reusable because of high temperature oxygen pick-up and contamination. This study carried out an extensive study on the effect of scanning speed on material efficiency by varying the speed between 0.01 to 0.1m/sec. The samples are wire brushed and cleaned with acetone after each deposition to remove un-melted particles from the surface of the deposit. The substrate is weighed before and after deposition. A formula was developed to calculate the material efficiency and the scanning speed was compared with the powder efficiency obtained. The results are presented and discussed. The study revealed that the optimum scanning speed exists for this study at 0.01m/sec, above and below which the powder efficiency will drop.
- Full Text:
- Authors: Akinlabi, Esther Titilayo , Mahamood, Rasheedat M. , Shukla, Mukul , Pityana, Sisa
- Date: 2012
- Subjects: Laser Metal Deposition Process , Material efficiency , Titanium alloy , Laser scanning speed
- Type: Article
- Identifier: uj:5337 , ISSN 2010-3778 , http://hdl.handle.net/10210/8880
- Description: The study of effect of laser scanning speed on material efficiency in Ti6Al4V application is very important because unspent powder is not reusable because of high temperature oxygen pick-up and contamination. This study carried out an extensive study on the effect of scanning speed on material efficiency by varying the speed between 0.01 to 0.1m/sec. The samples are wire brushed and cleaned with acetone after each deposition to remove un-melted particles from the surface of the deposit. The substrate is weighed before and after deposition. A formula was developed to calculate the material efficiency and the scanning speed was compared with the powder efficiency obtained. The results are presented and discussed. The study revealed that the optimum scanning speed exists for this study at 0.01m/sec, above and below which the powder efficiency will drop.
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Friction stir welding process : a green technology
- Akinlabi, Esther Titilayo, Akinlabi, Stephen A.
- Authors: Akinlabi, Esther Titilayo , Akinlabi, Stephen A.
- Date: 2012
- Subjects: Friction stir welding , Green technology
- Type: Article
- Identifier: uj:5335 , ISSN 2010-3778 , http://hdl.handle.net/10210/8878
- Description: Friction Stir Welding (FSW) is a solid state welding process invented and patented by The Welding Institute (TWI) in the United Kingdom in 1991 for butt and lap welding of metals and plastics. This paper highlights the benefits of friction stir welding process as an energy efficient and a green technology process in the field of welding. Compared to the other conventional welding processes, its benefits, typical applications and its use in joining similar and dissimilar materials are also presented.
- Full Text:
- Authors: Akinlabi, Esther Titilayo , Akinlabi, Stephen A.
- Date: 2012
- Subjects: Friction stir welding , Green technology
- Type: Article
- Identifier: uj:5335 , ISSN 2010-3778 , http://hdl.handle.net/10210/8878
- Description: Friction Stir Welding (FSW) is a solid state welding process invented and patented by The Welding Institute (TWI) in the United Kingdom in 1991 for butt and lap welding of metals and plastics. This paper highlights the benefits of friction stir welding process as an energy efficient and a green technology process in the field of welding. Compared to the other conventional welding processes, its benefits, typical applications and its use in joining similar and dissimilar materials are also presented.
- Full Text:
Treatment of acid mine drainage using un-activated bentonite and limestone
- Nkonyane, Thembelihle, Ntuli, Freeman, Muzenda, Edison
- Authors: Nkonyane, Thembelihle , Ntuli, Freeman , Muzenda, Edison
- Date: 2012
- Subjects: Acid mine drainage , Bentonite , Limestone , Heavy metal removal
- Type: Article
- Identifier: uj:6045 , ISSN 2010-3778 , http://hdl.handle.net/10210/10453
- Description: Please refer to full text to view abstract
- Full Text:
- Authors: Nkonyane, Thembelihle , Ntuli, Freeman , Muzenda, Edison
- Date: 2012
- Subjects: Acid mine drainage , Bentonite , Limestone , Heavy metal removal
- Type: Article
- Identifier: uj:6045 , ISSN 2010-3778 , http://hdl.handle.net/10210/10453
- Description: Please refer to full text to view abstract
- Full Text:
Employee empowerment to improve organizational effectiveness at South African Universities
- Motebele, M., Mbohwa, Charles
- Authors: Motebele, M. , Mbohwa, Charles
- Date: 2013
- Subjects: Employee empowerment , Organizational effectiveness , Colleges and universities - South Africa
- Type: Article
- Identifier: uj:6169 , ISSN 2010-3778 , http://hdl.handle.net/10210/13776
- Description: This paper scrutinizes employee empowerment and seeks to provide a model for its implementation which addresses needs identified in the literature but inadequately addressed previously in the context of South Africa. Empowerment is a process whereby a culture of empowerment is developed, information is shared, competency is developed, and resources and support are provided. The benefits of employee empowerment are noted, and objections to it are addressed. Theoretical foundations of employee empowerment are examined in practice. A model for understanding and implementing employee empowerment is discussed. Employees in universities in South Africa are viewed first as apprentices while their skills and knowledge within a given task set are developing, then journey persons through continued development, and finally as leaders of their craft. An assessment of organizational empowerment is provided and training responses based upon this assessment are suggested.
- Full Text:
- Authors: Motebele, M. , Mbohwa, Charles
- Date: 2013
- Subjects: Employee empowerment , Organizational effectiveness , Colleges and universities - South Africa
- Type: Article
- Identifier: uj:6169 , ISSN 2010-3778 , http://hdl.handle.net/10210/13776
- Description: This paper scrutinizes employee empowerment and seeks to provide a model for its implementation which addresses needs identified in the literature but inadequately addressed previously in the context of South Africa. Empowerment is a process whereby a culture of empowerment is developed, information is shared, competency is developed, and resources and support are provided. The benefits of employee empowerment are noted, and objections to it are addressed. Theoretical foundations of employee empowerment are examined in practice. A model for understanding and implementing employee empowerment is discussed. Employees in universities in South Africa are viewed first as apprentices while their skills and knowledge within a given task set are developing, then journey persons through continued development, and finally as leaders of their craft. An assessment of organizational empowerment is provided and training responses based upon this assessment are suggested.
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Improving company throughput at a South African company
- Motebele, Makhala Mpho, Mbohwa, Charles
- Authors: Motebele, Makhala Mpho , Mbohwa, Charles
- Date: 2013
- Subjects: Customer loyalty , Consumer satisfaction , Branding (Marketing)
- Type: Article
- Identifier: uj:6171 , ISSN 2010-3778 , http://hdl.handle.net/10210/13778
- Description: Research has largely concentrated on customer responses to the products they have received from tiger brands. The present study sheds light on the determinants of customer loyalty to a content-based service, improving company business processes and optimum productivity in a manufacturing company. General fundamentals of productivity must build a loyal customer base in order to attract repeat business and have a competitive advantage over competitors. Need fulfillment, responsiveness, security and technical functionality of the company are shown to influence productivity. Managerial implications are provided.
- Full Text:
- Authors: Motebele, Makhala Mpho , Mbohwa, Charles
- Date: 2013
- Subjects: Customer loyalty , Consumer satisfaction , Branding (Marketing)
- Type: Article
- Identifier: uj:6171 , ISSN 2010-3778 , http://hdl.handle.net/10210/13778
- Description: Research has largely concentrated on customer responses to the products they have received from tiger brands. The present study sheds light on the determinants of customer loyalty to a content-based service, improving company business processes and optimum productivity in a manufacturing company. General fundamentals of productivity must build a loyal customer base in order to attract repeat business and have a competitive advantage over competitors. Need fulfillment, responsiveness, security and technical functionality of the company are shown to influence productivity. Managerial implications are provided.
- Full Text:
Wellness programs with a view to improvement in operational performance at a South African food manufacturer
- Motebele, Makhala Mpho, Mbohwa, Charles
- Authors: Motebele, Makhala Mpho , Mbohwa, Charles
- Date: 2013
- Subjects: Food industry and trade - Employees - Health and hygiene , Shift work - Health aspects , Employee health promotion
- Type: Article
- Identifier: uj:6179 , ISSN 2010-3778 , http://hdl.handle.net/10210/13786
- Description: This study betters understanding and provides an outline of the negative effects that shift work has on employee health and wellness in food manufacturing company in South Africa. Given the realities of the modern day employee rights and well-being there is need to consider how these can be achieved whilst concurrently improving organisational effectiveness and performance. It is imperative that we understand the health effects at the work place and more importantly determine what can be done to reduce the negative health impact that shift work has on employee’s wellness. To this end, the objectives of this paper is to: Highlight the negative effects that night shift or irregular shift patterns have on employee health and wellness; Establish what programs can be developed by the employer to reduce the above negative effects; Establish if improved employee health and wellness for shift workers could lead to improved business performance. The paper establishes the relationship between shift work and the negative health effects on employees in a South African Food Manufacturing Company, and determines if programs can be implemented to counteract or limit these negative effects, thereby resulting in an improvement in operational performance.
- Full Text:
- Authors: Motebele, Makhala Mpho , Mbohwa, Charles
- Date: 2013
- Subjects: Food industry and trade - Employees - Health and hygiene , Shift work - Health aspects , Employee health promotion
- Type: Article
- Identifier: uj:6179 , ISSN 2010-3778 , http://hdl.handle.net/10210/13786
- Description: This study betters understanding and provides an outline of the negative effects that shift work has on employee health and wellness in food manufacturing company in South Africa. Given the realities of the modern day employee rights and well-being there is need to consider how these can be achieved whilst concurrently improving organisational effectiveness and performance. It is imperative that we understand the health effects at the work place and more importantly determine what can be done to reduce the negative health impact that shift work has on employee’s wellness. To this end, the objectives of this paper is to: Highlight the negative effects that night shift or irregular shift patterns have on employee health and wellness; Establish what programs can be developed by the employer to reduce the above negative effects; Establish if improved employee health and wellness for shift workers could lead to improved business performance. The paper establishes the relationship between shift work and the negative health effects on employees in a South African Food Manufacturing Company, and determines if programs can be implemented to counteract or limit these negative effects, thereby resulting in an improvement in operational performance.
- Full Text:
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