The generation of compressed air comprises 20% of the total electricity usage in the mining industry, although compressed air is often seen as a free source of energy. There are however significant costs associated with generating compressed air and maintaining a compressed air system. There are several methods to optimise the electricity used to generate compressed air. The focus of this study is on one of these methods – the implementation of a dynamic air compressor selector. A Dynamic Compressor Selector (DCS) system was developed to fulfil this purpose. DCS is a system that combines demand- and supply-side management of a compressed air network. DCS calculates a pressure set point for compressors and schedules the compressors according to the demand from the end-users. End-users include shafts, plants, workshops and smelters. DCS takes all of the compressors and end-users into consideration while doing the calculations. This dissertation focuses on the DCS implementation process and on the problems encountered by previous authors while implementing the DCS technology. Additional problems were encountered while the DCS technology was implemented. DCS was however still successfully implemented. This study will expand the implementation procedure to ensure that the technology can be implemented successfully in the future. DCS was implemented at a platinum mine in South Africa where it was able to calculate pressure set points for the compressors. DCS was able to accurately match the supply of, and demand for compressed air closely, resulting in lower overall compressed air usage. DCS improved compressor scheduling and control, limiting compressor cycling. Improved compressor scheduling and control resulted in significant decreases in the electricity used to generate compressed air at the mine. A target average evening peak clip of 2.197 MW was simulated, set and achieved. Evening peak clip power savings in excess of an average of 3 MW were achieved. / MIng (Mechanical Engineering), North-West University, Potchefstroom Campus, 2015

The generation of compressed air comprises 20% of the total electricity usage in the mining industry, although compressed air is often seen as a free source of energy. There are however significant costs associated with generating compressed air and maintaining a compressed air system. There are several methods to optimise the electricity used to generate compressed air. The focus of this study is on one of these methods – the implementation of a dynamic air compressor selector. A Dynamic Compressor Selector (DCS) system was developed to fulfil this purpose. DCS is a system that combines demand- and supply-side management of a compressed air network. DCS calculates a pressure set point for compressors and schedules the compressors according to the demand from the end-users. End-users include shafts, plants, workshops and smelters. DCS takes all of the compressors and end-users into consideration while doing the calculations. This dissertation focuses on the DCS implementation process and on the problems encountered by previous authors while implementing the DCS technology. Additional problems were encountered while the DCS technology was implemented. DCS was however still successfully implemented. This study will expand the implementation procedure to ensure that the technology can be implemented successfully in the future. DCS was implemented at a platinum mine in South Africa where it was able to calculate pressure set points for the compressors. DCS was able to accurately match the supply of, and demand for compressed air closely, resulting in lower overall compressed air usage. DCS improved compressor scheduling and control, limiting compressor cycling. Improved compressor scheduling and control resulted in significant decreases in the electricity used to generate compressed air at the mine. A target average evening peak clip of 2.197 MW was simulated, set and achieved. Evening peak clip power savings in excess of an average of 3 MW were achieved. / MIng (Mechanical Engineering), North-West University, Potchefstroom Campus, 2015

The Department of Correctional Services (Johannesburg Management Area) is established in the South of Johannesburg in Gauteng Province. It was founded in 1982. According to the Annual Report of the Department of Correctional Services 2009, the institution was initially developed to house 2630 offenders. Presently it accommodates 10130 offenders. These offenders are dependent on the number of facilities and officials for rehabilitation purpose. The discrepancy in the number of officials to that of offenders is a challenge within the Department of Correctional Services with regard to skills development. The study was based on the hypothesis that “effective implementation of skills development within Johannesburg Management Area may lead to a successful social reintegration of offenders”. The empirical research was conducted to support the hypothesis. Questionnaire was distributed and interviews were conducted to obtain responses. the findings reveal that offenders who are skilled are easy to be reintegrated and at the same time skilled officials are able to play a vital role in facilitating the social reintegration of offenders Study further reveals that skilled officials are able to network on behalf of offenders with ease and are able to increase job opportunities for offenders who are already on social reintegration programme. The study recommends that the Johannesburg Management area need to restructure its human resource development office, ensure that experienced and qualified facilitators are employed. Each correctional centre should have qualified facilitators who are experienced in adult education to skill offenders in various areas of development. The study leaves a scope for future research stating that Department of Correctional Services do further analysis on skills development and Social reintegration of offenders nationally to find a common and standard approach that will assist in the full reintegration of offenders / M, Development and Management, North-West University, Vaal Triangle Campus, 2011

This work attempts to offer an insight into the problematic of the genus Elettariopsis Baker, the last unrevised genus in the subfamily Alpinioideae (Zingiberaceae). Phylogenetic analyses are performed on ITS, matK and DCS sequence data and correlated with absolute genome size and biogeographical distribution of the samples. Elettariopsis as a genus is found to be weakly supported and strongly supported only with the addition of some species of Amomum Roxb., including the type species A. subulatum. The absolute genome size in this group is greater than in the outgroup represented by members of the Zingiberoideae subfamily. The evidence given by sequence data further suggests that Elettariopsis is divided into two well-supported groups, the "E. curtisii" group and the "E. triloba/E. unifolia" group, each of which contains several well-supported clades. In the analysis of absolute genome size it is shown that the absolute genome size in the "E. triloba/E.unifolia" group is higher than in the "E. curtisii" group. These two groups also differ slightly in their biogeographical distribution, the group G being distributed in only in Vietnam, Laos, and Thailand, while members of group H are also occurring in Singapore and Indonesia (Borneo). Keywords: Zingiberaceae, Elettariopsis, South-East Asia, ITS,...

O objetivo principal deste trabalho de Mestrado é avaliar compensadores que tentam diminuir o efeito do atrito estático existente em válvulas de controle. Os compensadores de atrito utilizados neste trabalho foram: CR1, CR2 Knocker, Two-move, controle por modos deslizantes e controle por modos deslizantes integrador. Estes compensadores são implementados em um ambiente industrial (SDCD). Devido ao atrito, o sistema tem um comportamento não-linear, o qual pode afetar o bom rendimento de um controlador PID, sendo que o sistema em malha fechada pode ter oscilações. Então, para obter uma diminuição do efeito do atrito, empregam-se compensadores de atrito. Para implementá-los, é necessário conhecer os parâmetros do atrito existente. Portanto, a primeira parte deste trabalho consiste em uma explicação dos diferentes modelos e métodos que se vai usar neste trabalho. Também foram realizadas simulações das estratégias de controle utilizadas. Após estes tópicos, vai se identificar o modelo do sistema que conta com uma malha de controle de vazão, com o objetivo de auxiliar na sintonia do controlador PID. Depois, introduzem-se os compensadores de atrito, os quais tentam minimizar os índices ITAE (Integrated Time Absolute Error) e IAE (Integrated Absolute Error), bem como o desgaste que se produz nos equipamentos, devido ao uso (excessiva movimentação da haste das válvulas). O objetivo assumido é implementar as estratégias de controle em um software industrial. Os resultados mostraram que os compensadores CR1 e CR2 obtiveram os melhores índices de desempenho e conseguiram compensar o atrito na haste da válvula de controle. / The main objective of this work is to evaluate compensators that try to decrease the static friction effect existent in control valves. The friction compensaters used in this work were: CR1, CR2, Knocker, Two-move, sliding mode control and sliding mode control with integrator. These compensators are implemented in an industrial environment (DCS). Due to friction, the system has a nonlinear behavior, which may affect the good performance of a PID controller, wherein the closed loop system can have oscillations. So to get a decrease in the effect of friction, friction compensators are employed. To implement them, it is necessary to know the parameters of the friction existent. So the first part of this work consists of an explanation of the different models and methods that will be use in this work. Also, simulations were made of the control strategies used. After these topics, it will be identify the system model which has a own control loop, in order to help the PID controller tuning. Then it will be introduced friction compensators, which attempt to minimize the ITAE (Integral Time Absolute Error) and IAE (Integrated Absolute Error), and wear that occurs on the equipment due to the use (excessive movement of the valve stem). The assumed objective is to implement control strategies in industrial software. The results show that the compensators CR1 and CR2 have the best performance indexes and they compensate for the friction in the control valve stem.

Bacillus anthracis produces lethal toxin (LT) and edema toxin (ET) and they suppress the function of LPS-stimulated dendritic cells (DC). Because DCs respond differently to various microbial stimuli, we compared toxin effects in bone marrow DCs stimulated with either LPS or Legionella pneumophila (Lp). DCs were enriched with GM-CSF for 9 days, purified by positive selection, and treated with toxins for 6h; cells were then stimulated with either LPS or Lp-infection for 24h. DC cytokine production and maturation marker expression varied depending upon cell stimulus and the mouse strain used. LT but not ET was more toxic for cells from BALB/c than from C57BL/6 (B6) as measured by 7-AAD uptake; however, ET suppressed CD11c expression. LT suppressed IL-12, IL-6, and TNF-a in cells from BALB/c and B6 mice but increased IL-1ß in LPS-stimulated cultures. ET also suppressed IL-12 and TNF-a but increased IL-6 and IL-1ß in Lp-stimulated cells from B6. Regarding maturation marker expression, LT increased MHCII and CD86 while suppressing CD40 and CD80; ET, on the other hand, generally decreased marker expression across all groups. We conclude that the modulation of cytokine production by anthrax toxins is dependent on variables including the source of the DCs, the type of stimulus and cytokine measured, and the individual toxin tested. However, LT and ET enhancement or suppression of maturation marker expression is more related to the marker studied than the cell stimulus or cell source. Anthrax toxins are not uniformly suppressive of DC function but instead can increase function under defined conditions.

It is clear that dendritic cells (DCs) are essential for priming of T cell responses against tumors. However, the distinct roles DC subsets play in regulation of T cell responses in vivo are largely undefined. In this study, we investigated the capacity of ovalbumin (OVA)-presenting CD48, CD4+8, or CD48+ DCs (OVA-pulsed DC (DCOVA)) from mouse spleen in stimulation of OVA-specific T cell responses. Our data show that each DC subset stimulated proliferation of allogeneic and autologous OVA-specific CD4+ and CD8+ T cells in vitro, but that the CD48 DCs did so only weakly. Both CD4+8 and CD48+ DCOVA induced strong tumor-specific CD4+ Th1 responses and fully protective CD8+ cytotoxic T lymphocyte (CTL)-mediated antitumor immunity, whereas CD48 DCOVA, which were less mature and secreted substantial transforming growth factor (TGF- ) upon coculture with T cell receptor (TCR)-transgenic OT II CD4+ T cells, induced the development of interleukin-10 (IL-10)-secreting CD4+ T regulatory 1 (Tr1) cells. Transfer of these Tr1 cells, but not T cells from cocultures of CD48 DCOVA and IL-10/ OT II CD4+ T cells, into CD48+ DCOVA-immunized animals abrogated otherwise inevitable development of antitumor immunity. Taken together, CD48 DCs stimulate development of IL-10-secreting CD4+ Tr1 cells that mediated immune suppression, whereas both CD4+8 and CD48+ DCs effectively primed animals for protective CD8+ CTL-mediated antitumor immunity. <p> Different DC subsets play distinct roles in immune responses. CD4-8- DCs secreting TGF-â stimulate CD4+ regulatory T type 1 (Trl) cell responses leading to inhibition of CD8 CTL responses and antitumor immunity. In this study, we explored the potential effect of three stimuli CpG, lipopolysaccharide (LPS) and anti-CD40 antibody in conversion of CD4-8- DC-induced tolerance. We demonstrated that when CD4-8- DCs were isolated from overnight culture and cultured for another 8 hrs in AIM-V plus recombinant mouse granulocyte-macrophage colony-stimulating factor (rmGM-CSF) (15-20 ng/ml) and OVA (0.1 mg/ml) with CpG (5 ug/ml), LPS (2 ug/ml) and anti-CD40 antibody (10 ug/ml), their phenotype became more mature compared with the freshly isolated ones. CpG is the only agent that stimulates the DCs to secrete significant level of interleukin-6 (IL-6) and interleukin-15 (IL-15); DNA array analyses also indicate that CpG stimulates higher expression of IL-6 and IL-15 mRNA. CpG treatment most efficiently converts the tolerogenic DCs into immunogenic ones which stimulated the OTII CD4+ T cell to become T helper type 1 (Th1) and T helper type 17 (Th17) rather Tr1, while the other two stimulator-treated DCs could not induce Th17 response. Their vaccination also induced the strongest antitumor CTL responses and protective immunity against tumor cell challenge. When CD4-8- DCs were isolated from IL-6 knock out (IL-6-/-) mice, CpG-treated DCOVA vaccination almost completely lost their animal protection capacity. Wild type B6 DCOVA-vaccinated IL-15 receptor knock out (IL-15R-/-) mice can only provide up to 30% protection against tumor challenge. Those results indicate that IL-6/ IL-l5-induced Th17 plays a critical role in their conversion. Taken together, our findings indicate that CpG treatment is the most efficient agent that can convert tolerogenic DCs into immunogenic ones and induce long-lasting antitumor immunity. We previously demonstrated that the nonspecific CD4+ T cells can acquire antigen-specific DC-released exosomes (EXO) and these CD4+ T cells with acquired exosomal MHC I peptide complex (pMHC I) can stimulate antigen-specific CD8+ CTL responses. In my project we have found that CD4-8-DCs could induce regulatory T cell type 1(Tr1) response, thus it would be very necessary to know whether regulatory T cells would change their antigen specificity if they got the membrane complex from DC through coculture or DC-derived exosome pulsing. During the beginning of my regulatory T cell project, we found that CD8+CD25+ Tr were much more easily expanded, while CD4+CD25+ Tr usually began to die just after 3 days in vitro culture and its very hard to get enough cells for further research. Therefore, CD8+CD25+ were used as a model Tr cells in the following project. To assess whether the nonspecific CD8+CD25+ Tr cells can acquire antigen-specificity via acquired exosomal pMHC I, we purified CD8+CD25+ Tr cells from wild-type C57BL/6 mice and OVA-pulsed DCOVA-released EXOOVA expressing pMHC I complexes. We demonstrated that the nonspecific CD8+CD25+ Tr cells expressing forkhead box P3 (Foxp3), cytotoxic T-Lymphocyte Antigen 4 (CTLA-4), glucocorticoid-induced tumor necrosis factor receptor (GITR), perforin and granzyme B inhibited in vitro T cell proliferation and in vivo OVA-specific CD4+ T cell-dependent and independent CD8+ CTL responses and antitumor immunity. CD8+CD25+ Tr cells suppressive effect is possibly mediated through its inhibition of DC maturation, down-regulation of secretion of Th1 polarization cytokines by DCs and its induction of T cell anergy via cell-to-cell contact. The nonspecific CD8+CD25+ Tr cells acquired antigen specificity by uptake of DCOVA-released EXOOVA expressing pMHC I and enhanced its effect on inhibition of OVA-specific CD8+ T cell responses and antitumor immunity by 10-folds. The principles elucidated in this study may have significant implications not only in antitumor immunity, but also in other sectors of immunology (e.g, autoimmunity and transplantation).

It is clear that dendritic cells (DCs) are essential for priming of T cell responses against tumors. However, the distinct roles DC subsets play in regulation of T cell responses in vivo are largely undefined. In this study, we investigated the capacity of ovalbumin (OVA)-presenting CD48, CD4+8, or CD48+ DCs (OVA-pulsed DC (DCOVA)) from mouse spleen in stimulation of OVA-specific T cell responses. Our data show that each DC subset stimulated proliferation of allogeneic and autologous OVA-specific CD4+ and CD8+ T cells in vitro, but that the CD48 DCs did so only weakly. Both CD4+8 and CD48+ DCOVA induced strong tumor-specific CD4+ Th1 responses and fully protective CD8+ cytotoxic T lymphocyte (CTL)-mediated antitumor immunity, whereas CD48 DCOVA, which were less mature and secreted substantial transforming growth factor (TGF- ) upon coculture with T cell receptor (TCR)-transgenic OT II CD4+ T cells, induced the development of interleukin-10 (IL-10)-secreting CD4+ T regulatory 1 (Tr1) cells. Transfer of these Tr1 cells, but not T cells from cocultures of CD48 DCOVA and IL-10/ OT II CD4+ T cells, into CD48+ DCOVA-immunized animals abrogated otherwise inevitable development of antitumor immunity. Taken together, CD48 DCs stimulate development of IL-10-secreting CD4+ Tr1 cells that mediated immune suppression, whereas both CD4+8 and CD48+ DCs effectively primed animals for protective CD8+ CTL-mediated antitumor immunity. <p> Different DC subsets play distinct roles in immune responses. CD4-8- DCs secreting TGF-â stimulate CD4+ regulatory T type 1 (Trl) cell responses leading to inhibition of CD8 CTL responses and antitumor immunity. In this study, we explored the potential effect of three stimuli CpG, lipopolysaccharide (LPS) and anti-CD40 antibody in conversion of CD4-8- DC-induced tolerance. We demonstrated that when CD4-8- DCs were isolated from overnight culture and cultured for another 8 hrs in AIM-V plus recombinant mouse granulocyte-macrophage colony-stimulating factor (rmGM-CSF) (15-20 ng/ml) and OVA (0.1 mg/ml) with CpG (5 ug/ml), LPS (2 ug/ml) and anti-CD40 antibody (10 ug/ml), their phenotype became more mature compared with the freshly isolated ones. CpG is the only agent that stimulates the DCs to secrete significant level of interleukin-6 (IL-6) and interleukin-15 (IL-15); DNA array analyses also indicate that CpG stimulates higher expression of IL-6 and IL-15 mRNA. CpG treatment most efficiently converts the tolerogenic DCs into immunogenic ones which stimulated the OTII CD4+ T cell to become T helper type 1 (Th1) and T helper type 17 (Th17) rather Tr1, while the other two stimulator-treated DCs could not induce Th17 response. Their vaccination also induced the strongest antitumor CTL responses and protective immunity against tumor cell challenge. When CD4-8- DCs were isolated from IL-6 knock out (IL-6-/-) mice, CpG-treated DCOVA vaccination almost completely lost their animal protection capacity. Wild type B6 DCOVA-vaccinated IL-15 receptor knock out (IL-15R-/-) mice can only provide up to 30% protection against tumor challenge. Those results indicate that IL-6/ IL-l5-induced Th17 plays a critical role in their conversion. Taken together, our findings indicate that CpG treatment is the most efficient agent that can convert tolerogenic DCs into immunogenic ones and induce long-lasting antitumor immunity. We previously demonstrated that the nonspecific CD4+ T cells can acquire antigen-specific DC-released exosomes (EXO) and these CD4+ T cells with acquired exosomal MHC I peptide complex (pMHC I) can stimulate antigen-specific CD8+ CTL responses. In my project we have found that CD4-8-DCs could induce regulatory T cell type 1(Tr1) response, thus it would be very necessary to know whether regulatory T cells would change their antigen specificity if they got the membrane complex from DC through coculture or DC-derived exosome pulsing. During the beginning of my regulatory T cell project, we found that CD8+CD25+ Tr were much more easily expanded, while CD4+CD25+ Tr usually began to die just after 3 days in vitro culture and its very hard to get enough cells for further research. Therefore, CD8+CD25+ were used as a model Tr cells in the following project. To assess whether the nonspecific CD8+CD25+ Tr cells can acquire antigen-specificity via acquired exosomal pMHC I, we purified CD8+CD25+ Tr cells from wild-type C57BL/6 mice and OVA-pulsed DCOVA-released EXOOVA expressing pMHC I complexes. We demonstrated that the nonspecific CD8+CD25+ Tr cells expressing forkhead box P3 (Foxp3), cytotoxic T-Lymphocyte Antigen 4 (CTLA-4), glucocorticoid-induced tumor necrosis factor receptor (GITR), perforin and granzyme B inhibited in vitro T cell proliferation and in vivo OVA-specific CD4+ T cell-dependent and independent CD8+ CTL responses and antitumor immunity. CD8+CD25+ Tr cells suppressive effect is possibly mediated through its inhibition of DC maturation, down-regulation of secretion of Th1 polarization cytokines by DCs and its induction of T cell anergy via cell-to-cell contact. The nonspecific CD8+CD25+ Tr cells acquired antigen specificity by uptake of DCOVA-released EXOOVA expressing pMHC I and enhanced its effect on inhibition of OVA-specific CD8+ T cell responses and antitumor immunity by 10-folds. The principles elucidated in this study may have significant implications not only in antitumor immunity, but also in other sectors of immunology (e.g, autoimmunity and transplantation).

A numerical analysis scheme has been developed to extract dynamic information from experimental images by the three-dimensional sliced fluorescence imaging method. The present scheme is based on a generalized framework in analyzing fluorescence images from the photo-initiated dynamic process. Specifically, image quality optimization, noise reduction and numerical fitting codes have been implemented in the present scheme to determine differential cross sections of the state-to-state inelastic collisions between CN(A 2£S) and He. These codes are indispensable in extracting state-to-state dynamic information from experimental images in any photo-initiated collision experiment, no matter it is executed in the beam or bulb environment.

Studies of the optimum isolation in a multi-mode PDA phone are presented in this thesis. Firstly, we analyze the optimum isolation between the DCS and GPS antennas embedded in a dual-mode PDA phone. Then, we change the antenna types of the DCS system to study again the behavior of the optimum isolation. Secondly, we analyze the optimum isolation between a DCS antenna and a WLAN antenna embedded in a dual-mode PDA phone. Finally, we propose a multi-mode PDA phone for DCS, GPS, and WLAN operations with good isolation among the three internal antennas.