As cidades, notadamente aquelas identificadas como de porte médio, acabam absorvendo mudanças de qualidade e passam a centralizar atividades econômicas. Se, por um lado, a urbanização traz oportunidades para o desenvolvimento social e econômico, de outro, resulta em significativa perda nas funcionalidades básicas e exerce pressão sobre as infraestruturas e recursos naturais. As Tecnologias da Informação e Comunicação (TIC) surgem como aliadas no enfrentamento a estes desafios. Baseadas no uso das TIC, iniciativas de Cidades Inteligentes exploram a instrumentalização das infraestruturas da cidade. Na tentativa de unificar a gestão dos diversos aspectos das cidades, por meio do monitoramento e análise em tempo real de dados públicos, diversas capitais estaduais do Brasil já contam com o suporte de centros de controle integrados. Dado o exposto, o presente trabalho propõe um modelo para a estruturação de Centros de Controle Integrados (CCI), compatíveis com a realidade de municípios de médio porte. Para tanto, por meio da revisão da literatura e de uma entrevista junto ao Centro Integrado de Comando da Cidade de Porto Alegre (CEIC), realizou-se o levantamento das melhores práticas a respeito da implantação de centros de controle. Complementarmente, entrevistaram-se os responsáveis de quatro prefeituras municipais para a determinação dos modelos de controle instituídos em cidades de médio porte. Para fins de validação, deu-se a avaliação do modelo por três especialistas da área de estudo. O modelo proposto – composto pelas dimensões de (i) coordenação, (ii) design, (iii) gerenciamento, (iv) comunicação, (v) práticas e rotinas de trabalho e (vi) processamento e gerenciamento de evidências, resulta do cruzamento destas informações e contribui, como ferramenta de gestão, para o desenvolvimento estruturado das cidades de médio porte. / The cities, especially those identified as medium-sized cities, end up absorbing quality changes and begin to centralize economic activities. If, on the one hand, urbanization brings opportunities for social and economic development, on the other hand, it results in a significant loss of basic functionalities, jeopardizing infrastructure and natural resources. In this way, Information and Communication Technologies (ICT) emerge as an alliy in face of these challenges. Based on the use of ICT, Smart Cities initiatives explore the instrumentalization of the city's infrastructures. In an attempt to unify the management of the various aspects of cities through real-time monitoring and analysis of public data, several state capitals in Brazil already rely on the support of Integrated Control Centers. Thus, the present work proposes a model for structuring the Integrated Control Centers (ICC), compatible with the reality of medium-sized municipalities. Through a literature review and an interview with the Centro Integrado de Comando of Porto Alegre (CEIC), the best practices regarding the implementation of control centers were surveyed. Complementarily, the heads of four city halls were interviewed to determine the control models established in medium-sized cities. Furthermore, the model was also assessed by three specialists in the study area. The proposed model - composed by the dimensions of (i) coordination, (ii) design, (iii) management, (iv) communication, (v) practices and work routines and (vi) processing and management of evidence, results from the cross-referencing of this information and contributes as a management tool to the structured development of medium-sized cities.

Baculoviruses are arthropod-specific DNA viruses that are highly virulent to most lepidopteran insects. Their host specificity and compatibility with IPM programmes has enabled their usage as safe microbial insecticides (biopesticides). Two baculovirus-based biopesticides, Cryptogran and Cryptex, which have been formulated with Cryptophlebia leucotreta granulovirus (CrleGV) have been registered for the control of false codling moth (FCM), Thaumatotibia (=Cryptophlebia) leucotreta (Meyrick) (Lepidoptera: Tortricidae) in South Africa and have been successfully incorporated into IPM programmes. However, several studies have indicated that insects can develop resistance to baculovirus-based biopesticide as was shown with field populations of codling moth (CM), Cydia pomonella (L.), which developed resistance to the biopesticide Cydia pomonella granulovirus (CpGV-M) in Europe. Other studies have shown that, under laboratory conditions, FCM populations differ in their susceptibility to Cryptogran and Cryptex. In order to investigate difference in susceptibility as well as protect against any future resistance by FCM to Cryptogran and Cryptex, a search for novel CrleGV-SA isolates from diseased insects from different geographic regions in South Africa was performed. Six geographic populations (Addo, Citrusdal, Marble Hall, Nelspruit, Baths and Mixed colonies) of FCM were established and maintained in the laboratory. Studies on the comparative biological performance based on pupal mass, female fecundity, egg hatch, pupal survival, adult eclosion and duration of life cycle of the Addo, Citrusdal, Marble Hall, Nelspruit and Mixed colonies revealed a low biological performance for the Citrusdal colony. This was attributed to the fact that FCM populations found in the Citrusdal area are not indigenous and may have been introduced from a very limited gene pool from another region. When insects from five colonies, excluding the Baths colony, were subjected to stress by overcrowding , a latent baculovirus resident in the Addo, Nelspruit, Citrusdal, Marble Hall and Mixed colonies was brought into an overt lethal state. Transmission electron micrographs revealed the presence of GV occlusion bodies (OBs) in diseased insects. DNA profiles obtained by single restriction endonuclease analysis of viral genomic DNA using BamH 1, Sa/1, Xba1 , Pst1, Xh01 , Kpn1, Hindlll and EcoR1 revealed five CrleGV-SA isolates latent within the insect populations. The new isolates were named CrleGV-SA Ado, CrleGV-SA Cit, CrleGV-SA Mbl, CrleGVSA Nels and CrleGV-SA Mix isolates. The novelty of the five CrleGV-SA isolates was confirmed by the presence of unique submolar bands, indicating that each isolate was genetically different. PCR amplification and sequencing of the granulin and egt genes from the five isolates revealed several single nucleotide polymorph isms (SNPs) which, in some cases, resulted in amino acid substitutions. DNA profiles from RFLPs, as well as phylogenetic analysis based on granulin and egt sequencing showed the presence of two CrleGV-SA genome types for the CrleGV-SA isolate. Cryptex and CrleGV-SA Ado, CrleGV-SA Cit, CrleGV-SA Mbl and CrleGV-SA Mix were placed as members of Group one CrleGV-SA, and Cryptogran and CrleGV-SA Nels isolate were placed into Group two CrleGV-SA. In droplet feeding bioassays, the median survival time (STso) for neonate larvae inoculated with Group one and two CrleGV-SA were determined to range from 80 - 88 hours (3.33 - 3.67 days), for all five colonies. LDso values for Group one and two CrleGV-SA against neonates from the Addo, Citrusdal, Marble Hall, Nelspruit and Mixed colonies varied between some populations and ranged from 0.80 - 3.12 OBs per larva, indicating some level of variation in host susceptibility. This is the first study reporting the existence of genetically distinct CrleGV baculovirus isolates infecting FCM in different geographical areas of South Africa. The results of this study have broad-ranging implications for our understanding of baculovirus-host interactions and for the application of baculovirus basedbiopesticides.

As cidades, notadamente aquelas identificadas como de porte médio, acabam absorvendo mudanças de qualidade e passam a centralizar atividades econômicas. Se, por um lado, a urbanização traz oportunidades para o desenvolvimento social e econômico, de outro, resulta em significativa perda nas funcionalidades básicas e exerce pressão sobre as infraestruturas e recursos naturais. As Tecnologias da Informação e Comunicação (TIC) surgem como aliadas no enfrentamento a estes desafios. Baseadas no uso das TIC, iniciativas de Cidades Inteligentes exploram a instrumentalização das infraestruturas da cidade. Na tentativa de unificar a gestão dos diversos aspectos das cidades, por meio do monitoramento e análise em tempo real de dados públicos, diversas capitais estaduais do Brasil já contam com o suporte de centros de controle integrados. Dado o exposto, o presente trabalho propõe um modelo para a estruturação de Centros de Controle Integrados (CCI), compatíveis com a realidade de municípios de médio porte. Para tanto, por meio da revisão da literatura e de uma entrevista junto ao Centro Integrado de Comando da Cidade de Porto Alegre (CEIC), realizou-se o levantamento das melhores práticas a respeito da implantação de centros de controle. Complementarmente, entrevistaram-se os responsáveis de quatro prefeituras municipais para a determinação dos modelos de controle instituídos em cidades de médio porte. Para fins de validação, deu-se a avaliação do modelo por três especialistas da área de estudo. O modelo proposto – composto pelas dimensões de (i) coordenação, (ii) design, (iii) gerenciamento, (iv) comunicação, (v) práticas e rotinas de trabalho e (vi) processamento e gerenciamento de evidências, resulta do cruzamento destas informações e contribui, como ferramenta de gestão, para o desenvolvimento estruturado das cidades de médio porte. / The cities, especially those identified as medium-sized cities, end up absorbing quality changes and begin to centralize economic activities. If, on the one hand, urbanization brings opportunities for social and economic development, on the other hand, it results in a significant loss of basic functionalities, jeopardizing infrastructure and natural resources. In this way, Information and Communication Technologies (ICT) emerge as an alliy in face of these challenges. Based on the use of ICT, Smart Cities initiatives explore the instrumentalization of the city's infrastructures. In an attempt to unify the management of the various aspects of cities through real-time monitoring and analysis of public data, several state capitals in Brazil already rely on the support of Integrated Control Centers. Thus, the present work proposes a model for structuring the Integrated Control Centers (ICC), compatible with the reality of medium-sized municipalities. Through a literature review and an interview with the Centro Integrado de Comando of Porto Alegre (CEIC), the best practices regarding the implementation of control centers were surveyed. Complementarily, the heads of four city halls were interviewed to determine the control models established in medium-sized cities. Furthermore, the model was also assessed by three specialists in the study area. The proposed model - composed by the dimensions of (i) coordination, (ii) design, (iii) management, (iv) communication, (v) practices and work routines and (vi) processing and management of evidence, results from the cross-referencing of this information and contributes as a management tool to the structured development of medium-sized cities.

The interaction between farmers, agricultural scientists and extension workers is sometimes overlooked in agricultural entomology. In an attempt to respond to this reality this study examines some foundation of this interaction in relation to the pest management practices of subsistence and small-scale farmers and also highlights the problems that might arise in the implementation of IPM. Problems involving pests occurrence; language barriers; beliefs, knowledge and perception about insects, and visual literacy are examined. The thesis has a two-fold focus, firstly the study of pests on cabbages of subsistence farmers in Grahamstown and secondly a broader focus on other aspects such as cultural entomology, perception of insects and visual literacy specifically in relation to Xhosa speaking people in the Eastern Cape. The most important crop for emergent farmers in the Eastern Cape are cabbages, which have a variety of pests of which diamondback moths and are the most important. Traditional pest management practices tend to influence the development of IPM programmes adopted by these farmers. Eastern Cape farmers apply periodic cropping systems, which had an effect on the population densities of diamondback moth (DBM), other lepidopteran pests and their parasitoids. Considering the maximum population densities of DBM, which were 0.2 - 2.9 larvae/plant, there were no major pest problems. The availability of parasitoids, even in highly disturbed and patchy environments, showed good potential for biological control. Since some extension officers cannot speak the local farmers’ language, a dictionary of insect names was formulated in their language (isiXhosa) to assist communication. Response-frequency distribution analysis showed that the dictionary is essentially complete. The literal translations of some names show that isiXhosa speakers often relate insects to people, or to their habitat or classify them according to their behaviour. Farmers from eight sites in the Eastern Cape were interviewed regarding their knowledge and perception of insect pests and their control thereof. To some extent, farmers still rely on cultural control and have beliefs about insects that reflected both reality and superstition. There is no difference between the Ciskei and Transkei regions regarding insect-related beliefs. Farmers generally lack an understanding of insect ecology. There is a need for farmers to be taught about insects to assist with the implementation of IPM. Leftover pesticides from commercial farms or detergents are sometimes used to manage the pests. When training illiterate or semi-literate farmers, it is important to understand their media literacy so as to design useful graphic and object training media. Generally farmers showed that they either understand graphic or object media depending on the features of the insects being looked at. These findings are discussed with regard to the potential development of IPM training material for subsistence and small-scale farmers in a community.

Les nématodes gastro-intestinaux sont l’une des contraintes majeures pour la santé des petits ruminants mis en pâture, entraînant de nombreuses pertes de production. Leur contrôle au moyen de traitements anthelminthiques est de moins en moins efficace à cause du développement de la résistance larvaire. De nombreuses recherches ont mené à l’étude de différentes stratégies complémentaires à l’utilisation massive de ces traitements chimiques : nutrition de l’hôte, gestion des pâtures, sélection génétique. Une approche de modélisation permet de simuler de multiples scénarios en minimisant l’effort expérimental, et notamment le recours à des infestations coûteuses en animaux, afin de trouver la meilleure stratégie de lutte intégrée du parasitisme. Le modèle épidémio-génétique précédemment développé par le Roslin Institute modélisant un troupeau d’agneaux en croissance infecté par le parasite T. circumcincta permet d’étudier l’impact d’une utilisation raisonnée des traitements, de la nutrition et de la résistance de l’hôte sur le niveau d’infection et de production du troupeau. Les travaux de la présente thèse consistaient à modifier ce modèle afin de modéliser des brebis adultes, notamment autour de la période d’agnelage où les besoins nutritionnels sont très importants. Cette modélisation a été complétée par la prise en compte du renouvellement d’un troupeau afin de considérer un troupeau durable, avec des accouplements, des réformes et des reproductions. Ainsi, notre modèle permet d’étudier les différentes stratégies de contrôle du parasite sur le long terme. Afin de s’assurer de la cohérence des sorties de cette modélisation avec des données réelles, le niveau d’infection a été comparé à celui de femelles infestées autour de l’agnelage. Cependant, comme de nombreux paramètres sont propres à la modélisation et donc non estimables à partir d’expérimentations, une analyse de sensibilité a aussi été mise en place pour dégager les paramètres qui contribuaient le plus à la variation du niveau d’infection. Parmi les parasites les plus fréquents chez le mouton, on trouve deux parasites majeurs T. circumcincta et H. contortus. Le parasite H. contortus est le plus virulent dans des climats chauds et humides, il nous paraissait donc utile de développer un nouveau modèle prenant en compte ce parasite. Préalablement, une méta-analyse des études utilisant des infections par le parasite H. contortus a été réalisée afin d’estimer les traits de vie du cycle parasitaire de ce parasite. Ces estimations ont ensuite été utilisées pour adapter le modèle épidémio-génétique à des infections par H. contortus. Cependant certains paramètres restent inconnus car ils ne sont pas estimables directement. C’est pourquoi nous avons réalisé l’estimation des trois paramètres inconnus principaux de notre modèle (précédemment soulignés par l’analyse de sensibilité sur T. circumcincta) en minimisant les écarts entre le niveau de charge parasitaire reportée dans une étude considérant des infestations successive par H. contortus ([25]) et nos simulations correspondantes. Dans cette thèse nous avons développé des modèles permettant d’évaluer sur le long terme les différentes stratégies de contrôle de deux nématodes gastro-intestinaux (T. circumcincta et H. contortus) dans les troupeaux ovins. Notamment, le modèle prenant en compte H. contortus pourra être utilisé pour prédire l’impact à l’échelle de l’élevage (nombre de traitements nécessaire, niveau d’infection des animaux) d’une sélection génétique sur la résistance au parasitisme dans une race. Les nématodes gastro-intestinaux sont l’une des contraintes majeures pour la santé des petits ruminants mis en pâture, entraînant de nombreuses pertes de production. Leur contrôle au moyen de traitements anthelminthiques est de moins en moins efficace à cause du développement de la résistance larvaire. ... / Gastro-intestinal parasitism is one of the most pervasive challenge for health and welfare in grazing small ruminants, leading to consequent production loss. Its control through the use of anthelminthic treatments is no longer sustainable due to the development of parasitic resistance to anthelmintics, but also due to environmental and consumer concerns. A substantial research effort proposed different supplementary control strategies to the massive use of anthelmintics: host nutrition, pasture management, breeding for resistance. Modelling approach allows for multiple scenarios to be considered without having to resort to experimentation in order to find the best integrated control strategies of parasitism. The epidemio-genetic model previously developed by the Roslin Institute modelling a growing lamb flock infected by the parasite T. circumcincta help to study the impact of rational use of anthelmintics, host nutrition and resistance on the flock level of infection and production. The researches of the current PhD thesis aimed to modify this model in order to add adult ewes modelling, especially around parturition where the nutritional requirements are very high. This modelling was improved by taking into account flock replacement in order to have a persistent flock with matings, reforms and reproductions. In this way, our model allows to study several control strategies of parasitism on long term perspective. In order to ensure adequacy of the model outputs to data, the infection level was compared to published data of ewes infected around parturition. However, some parameters were idiosyncratic to the modelling and then they were not be directly estimated from experiments. So a sensitivity analysis was also performed to highlight the parameters which mostly contribute to the infection level variations. Among the most prevalent parasites in sheep, T. circumcincta and H. contortus are the two main parasites. H. contortus is the most virulent parasite est le plus virulent parasite in hot and wet climates, so it is helpful to develop a similar model for this parasite. Beforehand, a meta-analysis of the published studies on infections with the H. contortus parasite was performed to estimate the main life history traits of its parasitic phase. Then, these estimations were used to change the epidemio-genetic model with H. contortus infections. However, some parameters remained unknown because they were not directly estimable. So, the three main unknown parameters (previously highlighted by the sensitivity analysis of the model with T. circumcincta infections) were estimated by minimizing the worm burden differences between published data of H. contortus trickle infection ([25]) and the corresponding model outputs. In this PhD thesis, models were developed in order to evaluate, in a long term perspective, several control strategies of two gastro-intestinal nematodes (T. circumcincta et H. contortus) infections in sheep flock. Notably, the model on H. contortus infections could be used to predict the impact of breeding for resistance to parasitism at the flock level (number of necessary treatments, infection level of the sheep).

Three sampling methods for estimating abundance of alfalfa weevil (AW) larvae (Hypera postica Gyllenhal) were evaluated for both accuracy and precision. Calibration equations were developed to convert intensity estimates of AW larvae among sampling methods. Greenhouse experiments evaluating the interaction of moisture stress and defoliation by AW larvae indicated that yield response of alfalfa to AW feeding is dependent on moisture stress levels. Field studies on the influence of AW feeding on alfalfa confirmed the importance of moisture stress in alfalfa tolerance to weevil feeding. Quadratic regression models are presented to predict yield loss and changes in stem density as a function of weevil intensity. A sequential sampling plan was developed and validated for use in pest management decision making. Validation of the plan indicated an average error rate of 1.8%, with the number of samples needed reduced by 55% in 1980, 53% in 1981, and 28% in 1982. A net benefit analysis the Virginia Alfalfa IPM program indicated that growers participating in the program during 1981-84 realized an estimated average increase in net revenue of $8.80 per hectare from the alfalfa weevil scouting program, and $28.13 per hectare from the potato leafhopper scouting program. / Ph. D. / incomplete_metadata

Thesis (MScConsEcol (Conservation Ecology and Entomology))--University of Stellenbosch, 2009. / ENGLISH ABSTRACT: Pseudococcus viburni (Signoret) (Hemiptera: Pseudococcidae) (obscure mealybug), is a common and serious pest of apples and pears in South Africa. Consumer and regulatory pressure to produce commodities under sustainable and ecologically compatible conditions has rendered chemical control options increasingly limited. Information on the seasonal occurrence of pests is but one of the vital components of an effective and sustainable integrated pest management system needed for planning the initiation of monitoring and determining when damage can be expected. It is also important to identify which orchards are at risk of developing mealybug infestations while development of effective and early monitoring tools for mealybug populations will help growers in making decisions with regards to pest management and crop suitability for various markets. It is also essential to determine the presence and efficacy of naturally occurring biological control agents in orchards so as to ascertain the potential of biological control as a viable alternative in orchards. However, under the current integrated pest management protocol, it has been difficult to determine this, due to the sporadic and relatively low incidence of mealybug infestations in some orchards, or by simply relying on naturally occurring field populations of biocontrol agents. Knowledge of the environmental conditions under which P. viburni population levels may become destructive is also essential for timing the release of insectary reared natural enemies as well as understanding the population ecology of this pest and its natural enemies. Information was gathered regarding the seasonal phenology of P. viburni and its natural enemies in pome fruit orchards in the Western Cape Province during the 2007/08 and 2008/09 growing seasons. Seasonal population studies showed that P. viburni has multiple overlapping generations with all life stages present throughout the year. The highest orchard infestations occurred during the summer period until early winter (January to early June). This was followed by a decrease in population from late June to November, before another increase in December. Presence-absence sampling of mealybugs on the host plant revealed that woody parts of the tree, such as the trunk and old stems were the most preferred sites for mealybug habitation, due to the availability of protected refuge sites. Migration of mealybug populations to newer growth and the upper sections of the tree crown, such as the new stems, leaves and eventually the fruit, was observed from December throughout the summer period until the early winter in June. Fruit colonization in both apples and pears commenced in January, when the fruit had developed a size sufficient for P. viburni to penetrate and occupy spaces such as the fruit core, calyx and stem end. There was no evidence of P. viburni occurring beneath the soil surface or on the roots of host trees. Two natural enemies of mealybugs, namely Pseudaphycus maculipennis (Mercet) and Coccidoxenoides perminutus (Girault), were found to be active in apple and pear orchards in the Western Cape. However, the status of C. perminutus as a parasite of P. viburni still needs to be verified despite evidence of emergence from P. viburni mummies, which was not sufficient enough to suggest that it is a useful biological control agent. Seasonal abundance trends of the two natural enemies revealed that their lifecycle is synchronized with that of the host. However, there was no evidence of P. maculipennis activity in Ceres. No predators were found during the course of this study. The rate of P. viburni parasitism at harvest was 46.52%, with P. maculipennis and C. perminutus constituting 98.966% and 1.034% of the parasitoids recovered from mealybug mummies, respectively. Studies on the use of pheromone traps as early monitoring tools for P. viburni showed that there was a positive and significant relationship between the fruit infestation and number of P. viburni adult males caught in pheromone-baited traps (r2 = 0.454). The action threshold level was estimated to be 2.5 male P. viburni caught per trap per fortnight at an economic threshold of 2% fruit infestation. / AFRIKAANSE OPSOMMING: Pseudococcus viburni (Signoret) (Hemiptera: Pseudococcidae) (ligrooswitluis), is ‘n algemene en ernstige plaag van appels en pere in Suid-Afrika. Druk deur verbruikers en regulasies om kommoditeite onder volhoubare en ekologies verenigbare toestande te produseer het chemiese beheeropsies toenemend beperk. Inligting oor die seisoenale voorkoms van plae is een van die essensiële komponente van ‘n effektiewe en volhoubare geïntegreerde plaagbestuurprogram. Dit is in die aanvanklike beplanning van monitering en om te bepaal wanneer skade verwag kan word. Dit is ook belangrik om boorde vroegtydig te identifiseer wat die risiko het om witluisbesmettings te ontwikkel. Die ontwikkeling van effektiewe en vroeë moniteringstegnieke vir witluisbevolkings sal produsente help met besluitneming rakende plaagbestuur en die geskiktheid van gewasse vir verskeie markte. Dit is ook noodsaaklik om die teenwoordigheid en effektiwiteit van biologiese beheer agente wat natuurlik in boorde voorkom te bepaal ten einde die potensiaal van biologiese beheer as ‘n lewensvatbare alternatief vas te stel. Onder die huidige geïntegreerde plaagbestuurprotokol was dit egter moeilik om laasgenoemde te bepaal weens die sporadiese en relatiewe lae voorkoms van witluisbesmettings in sommige boorde of deur bloot staat te maak op die veldpopulasies van biologiese beheer agente wat natuurlik voorkom. Kennis van die omgewingstoestande waaronder P. viburni bevolkingsvlakke skadelik raak is ook noodsaaklik vir die beplanning van vrylating van biologiese beheer agente, asook om die bevolkingsekologie van hierdie plaag en sy natuurlike vyande te verstaan. Inligting oor die seisoenale fenologie van P. viburni en sy natuurlike vyande in sagtevrugte boorde in die Westelike Kaapprovinsie is gedurende die 2007/08 en 2008/09 groeiseisoene versamel. Seisoenale bevolkingstudies het getoon dat P. viburni verskeie oorvleuelende generasies het met alle stadia teenwoordig regdeur die jaar.

<p>This doctoral thesis presents new ideas and research results on control of marine electric power system.</p><p>The main motivation for this work is the development of a control system, power management system (PMS) capable to improve the system robustness to blackout, handle major power system faults, minimize the operational cost and keep the power system machinery components under minimal stress in all operational conditions.</p><p>Today, the electric marine power system tends to have more system functionality implemented in integrated automation systems. The present state of the art type of tools and methods for analyzing marine power systems do only to a limited extent utilize the increased knowledge available within each of the mechanical and electrical engineering disciplines.</p><p>As the propulsion system is typically consisted of the largest consumers on the vessel, important interactions exists between the PMS and vessel propulsion system. These are interacted through the dynamic positioning (DP) controller, thrust allocation algorithm, local thruster controllers, generators' local frequency and voltage controllers. The PMS interacts with the propulsion system through the following main functions: available power static load control, load rate limiting control and blackout prevention control (i.e. fast load reduction). These functions serve to prevent the blackout and to ensure that the vessel will always have enough power.</p><p>The PMS interacts with other control systems in order to prevent a blackout and to minimize operational costs. The possibilities to maximize the performance of the vessel, increase the robustness to faults and decrease a component wear-out rate are mainly addressed locally for the individual control systems. The solutions are mainly implicative (for e.g. local thruster control, or DP thrust allocation), and attention has not been given on the interaction between these systems, the power system and PMS. Some of the questions that may arise regarding the system interactions, are as follows: how the PMS functionality may affect a local thruster control, how the local thruster control may affect the power system performance, how some consumers may affect the power system performance in normal operations and thus affect other consumers, how the power system operation may affect the susceptibility to faults and blackout, how various operating and weather conditions may affect the power system performance and thus propulsion performance though the PMS power limiting control, how propulsion performance may affect the overall vessel performance, which kind of faults can be avoided if the control system is re-structured, how to minimize the operational costs and to deal with the conflicting goals. This PhD thesis aims to provide answers to such questions.</p><p>The main contributions of this PhD thesis are:</p><p>− A new observer-based fast load reduction system for the blackout prevention control has been proposed. When compared to the existing fast load reduction systems, the proposed controller gives much faster blackout detection rate, high reliability in the detection and faster and more precise load reduction (within 150 miliseconds).</p><p>− New advanced energy management control strategies for reductions in the operational costs and improved fuel economy of the vessel.</p><p>− Load limiting controllers for the reduction of thruster wear-out rate. These controllers are based on the probability of torque loss, real-time torque loss and the thruster shaft</p><p>accelerations. The controllers provide means of redistributing thrust from load fluctuating thrusters to less load fluctuating ones, and may operate independently of the thrust allocation system. Another solution is also proposed where the load limiting controller based on thrust losses is an integrated part of DP thrust allocation algorithm.</p><p>− A new concept of totally integrated thrust allocation system, local thruster control and power system. These systems are integrated through PMS functionality which is contained within each thruster PLC, thereby distributed among individual controllers, and independent of the communications and dedicated controllers.</p><p>− Observer-based inertial controller and direct torque-loss controller (soft anti-spin controller) with particular attention to the control of machine wear-out rate. These controller contribute to general shaft speed control of electrical thrusters, generators and main propulsion prime movers.</p><p>The proposed controllers, estimators and concepts are demonstrated through time-domain simulations performed in MATLAB/SIMULINK. The selected data are typical for the required applications and may differ slightly for the presented cases.</p>

This doctoral thesis presents new ideas and research results on control of marine electric power system. The main motivation for this work is the development of a control system, power management system (PMS) capable to improve the system robustness to blackout, handle major power system faults, minimize the operational cost and keep the power system machinery components under minimal stress in all operational conditions. Today, the electric marine power system tends to have more system functionality implemented in integrated automation systems. The present state of the art type of tools and methods for analyzing marine power systems do only to a limited extent utilize the increased knowledge available within each of the mechanical and electrical engineering disciplines. As the propulsion system is typically consisted of the largest consumers on the vessel, important interactions exists between the PMS and vessel propulsion system. These are interacted through the dynamic positioning (DP) controller, thrust allocation algorithm, local thruster controllers, generators' local frequency and voltage controllers. The PMS interacts with the propulsion system through the following main functions: available power static load control, load rate limiting control and blackout prevention control (i.e. fast load reduction). These functions serve to prevent the blackout and to ensure that the vessel will always have enough power. The PMS interacts with other control systems in order to prevent a blackout and to minimize operational costs. The possibilities to maximize the performance of the vessel, increase the robustness to faults and decrease a component wear-out rate are mainly addressed locally for the individual control systems. The solutions are mainly implicative (for e.g. local thruster control, or DP thrust allocation), and attention has not been given on the interaction between these systems, the power system and PMS. Some of the questions that may arise regarding the system interactions, are as follows: how the PMS functionality may affect a local thruster control, how the local thruster control may affect the power system performance, how some consumers may affect the power system performance in normal operations and thus affect other consumers, how the power system operation may affect the susceptibility to faults and blackout, how various operating and weather conditions may affect the power system performance and thus propulsion performance though the PMS power limiting control, how propulsion performance may affect the overall vessel performance, which kind of faults can be avoided if the control system is re-structured, how to minimize the operational costs and to deal with the conflicting goals. This PhD thesis aims to provide answers to such questions. The main contributions of this PhD thesis are: − A new observer-based fast load reduction system for the blackout prevention control has been proposed. When compared to the existing fast load reduction systems, the proposed controller gives much faster blackout detection rate, high reliability in the detection and faster and more precise load reduction (within 150 miliseconds). − New advanced energy management control strategies for reductions in the operational costs and improved fuel economy of the vessel. − Load limiting controllers for the reduction of thruster wear-out rate. These controllers are based on the probability of torque loss, real-time torque loss and the thruster shaft accelerations. The controllers provide means of redistributing thrust from load fluctuating thrusters to less load fluctuating ones, and may operate independently of the thrust allocation system. Another solution is also proposed where the load limiting controller based on thrust losses is an integrated part of DP thrust allocation algorithm. − A new concept of totally integrated thrust allocation system, local thruster control and power system. These systems are integrated through PMS functionality which is contained within each thruster PLC, thereby distributed among individual controllers, and independent of the communications and dedicated controllers. − Observer-based inertial controller and direct torque-loss controller (soft anti-spin controller) with particular attention to the control of machine wear-out rate. These controller contribute to general shaft speed control of electrical thrusters, generators and main propulsion prime movers. The proposed controllers, estimators and concepts are demonstrated through time-domain simulations performed in MATLAB/SIMULINK. The selected data are typical for the required applications and may differ slightly for the presented cases.

The first serious outbreak of brown rust of sugarcane caused by Puccinia melanocephala Syd. & P. Syd. was reported in India in 1907. It was first reported in South Africa (SA) in 1941 on the variety Co301 and is now present in almost all the sugarcane growing areas of the world. In SA, it is now described as an important disease of sugarcane, causing yield losses of up to 26% in susceptible varieties. Within the SA sugar industry, rust is controlled through the use of resistant varieties as it is the most economical method of control. However, most of the newer varieties that are being released have an intermediate resistance rating for rust. An integrated management approach for the control of rust is therefore being investigated. Aspects investigated in this study included environmental conditions required for development of the disease i.e. epidemiology, the use of silicon (Si) as a cultural control method against brown rust and identification of gene sequences expressed in response to brown rust infection. For the epidemiology study, inoculated plants were incubated in a dew chamber at different temperatures and leaf wetness periods. The choice of leaf wetness duration and temperature was based on urediniospore germination studies. The optimum temperature for urediniospore germination and disease development at > 98% relative humidity was found to be between 20 and 25°C with nine hours of leaf wetness. Silicon has been shown to reduce the incidence of diseases and pests in a number of crops. The ability of sugarcane to accumulate Si and the location of Si deposition was established using two uptake and deposition trials. Different concentrations of Si were applied to the plant and accumulation in the roots, stalks, old leaves and young leaves was determined using inductively coupled plasma optical emission spectrometry, with accumulation found to be roots > old leaves > stalks > young leaves. Silicon deposition in the leaves was determined using energy dispersive X-ray mapping on freeze dried specimens and significant differences were found between the upper epidermis, lower epidermis and mesophyll with the most Si being deposited in the lower epidermis. For disease severity, plants were naturally infected with rust and rated weekly. A significant decrease in disease severity and area under disease progress curve was noted when the Si concentration increased, indicating that Si has potential in reducing rust incidence. Currently, the most reliable and economical method of managing brown rust is with the use of resistant varieties. Identification of resistance within breeding lines is therefore important. For this part of the study, suppression subtractive hybridization was used as a tool to identify differentially expressed genes between a susceptible and resistant variety and a susceptible and intermediate variety, in response to brown rust infection. Two efficient subtracted cDNA libraries were generated and differentially expressed sequences were identified within each library. The results of this study show potential for the development of molecular markers which could be used for the early identification of brown rust resistance during the breeding process. This study forms a firm basis on which an integrated management strategy, for the management of brown rust in the SA sugar industry, could be designed. The cDNA sequences identified could be further investigated and used to develop molecular markers to select for rust resistant varieties, the epidemiology results together with further field data could be used to develop a disease prediction model and Si has potential in the field to reduce brown rust severity. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2009.