Low Pressure Die Casting (LPDC) process is one the most common casting process to produce structural automotive components, such as alloy wheels and suspension components. It has been identified that cavity filling and solidification process are two most critical aspects to produce premium quality casting components.During the solidification process of casting alloy, it is a well known phenomenon that metal experiences volumetric shrinkage due to its density difference between liquid and solid phase. When this volumetric shrinkage is not properly compensated, then a casting defect commonly known as solidification shrinkage occurs. The solidification shrinkage has very detrimental effects on structural integrity required for premium quality casting such as aluminium alloy wheels.Literature and practical experiences of foundry men show that it is critical to achieve unidirectional solidification pattern by avoiding an isolated hot spot in order to minimise the solidification shrinkage. However, it is found that the geometry of industrial casting applications is often constrained by other design factors that would not naturally avoid these isolated hot spots. The subject of this research, aluminium alloy wheels, is not excluded from this constraint.In aluminium alloy wheels, an isolated hot spot is commonly observed in an area known as rim and spoke junction due to its geometry constraints. Consequently, the solidification shrinkage is commonly experienced, which is undesirable due to its detrimental effects for the structural integrity of alloy wheels. In order to minimise the solidification shrinkage, forced cooling method is applied to avoid an isolated hot spot. The control of this forced cooling is achieved by cooling media, flow rate of cooling media and duration cooling circuit. Foundry experiments in industrial environment were conducted producing aluminium alloy wheels using commercially treated A356 (Al-Si) alloy, where different durations of cooling circuit were used to understand the sensitivity of solidification shrinkage formation to the duration of cooling circuit. This was followed by metallurgical structure analysis and numerical modelling to suggest the sensitivity of cooling circuit duration in controlling solidification shrinkage.The major finding conclusion of this research is that control of the shrinkage formation is not very sensitive to the duration cooling circuit. It is suggested that as casting solidifies initially from the mould wall, it retracts away from the cast-mould interface due to thermal contraction. Consequently, air gap is formed between casting and mould interface, creating an effective thermal resistance layer. Thereafter, heat transfer across the cast-mould interface is not sensitive to the change in the cooling channel which is a distance to the cast-mould interface.Some limitations of numerical modelling and metallurgical analysis were also identified during this research and recommendations were made to improve the accuracy of local hot spot prediction in production of aluminium alloy wheels. More specifically, numerical modelling of the effect of grain refinement and use of non homogeneous material property (particularly fraction of solid) for rapidly chilled area. Fraction of eutectic rather than secondary dendrites arm spacing is a proper microstructure parameter that can be used to locate the hot spot.

Thesis (MA)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: Image classification has long been used in earth observation and is driven by the need for accurate maps to develop conceptual and predictive models of Earth system processes. Synthetic aperture radar (SAR) imagery is used ever more frequently in land cover classification due to its complementary nature with optical data. There is therefore a growing need for reliable, accurate methods for using SAR and optical data together in land use and land cover classifications. However, combining data sets inevitably increases data dimensionality and these large, complex data sets are difficult to handle. It is therefore important to assess the benefits and limitations of using multi-temporal, dual-sensor data for applications such as land cover classification. This thesis undertakes this assessment through four main experiments based on combined RADARSAT-2 and SPOT-5 imagery of the southern part of Reunion Island. In Experiment 1, the use of feature selection for dimensionality reduction was considered. The rankings of important features for both single-sensor and dual-sensor data were assessed for four dates spanning a 6-month period, which coincided with both the wet and dry season. The mean textural features produced from the optical bands were consistently ranked highly across all dates. In the two later dates (29 May and 9 August 2014), the SAR features were more prevalent, showing that SAR and optical data have complementary natures. SAR data can be used to separate classes when optical imagery is insufficient. Experiment 2 compared the accuracy of six supervised and machine learning classification algorithms to determine which performed best with this complex data set. The Random Forest classification algorithm produced the highest accuracies and was therefore used in Experiments 3 and 4. Experiment 3 assessed the benefits of using combined SAR-optical imagery over single-sensor imagery for land cover classifications on four separate dates. The fused imagery produced consistently higher overall accuracies. The 29 May 2014 fused data produced the best accuracy of 69.8%. The fused classifications had more consistent results over the four dates than the single-sensor imagery, which suffered lower accuracies, especially for imagery acquired later in the season. In Experiment 4, the use of multi-temporal, dual-sensor data for classification was evaluated. Feature selection was used to reduce the data set from 638 potential training features to 50, which produced the best accuracy of 74.1% in comparison to 71.9% using all of the features. This result validated the use of multi-temporal data over single-date data for land cover classifications. It also validated the use of feature selection to successfully inform data reduction without compromising the accuracy of the final product. Multi-temporal and dual-sensor data shows potential for mapping land cover in a tropical, mountainous region that would otherwise be challenging to map using single-sensor data. However, accuracies Stellenbosch University https://scholar.sun.ac.za iv generally remained lower than would allow for transferability and replication of the current methodology. Classification algorithm optimisation, supervised segmentation and improved training data should be considered to improve these results. / AFRIKAANSE OPSOMMING: Beeld-klassifikasie word al ‘n geruime tyd in aardwaarneming gebruik en word gedryf deur die behoefte aan akkurate kaarte om konseptuele en voorspellende modelle van aard-stelsel prosesse te ontwikkel. Sintetiese apertuur radar (SAR) beelde word ook meer dikwels in landdekking klassifikasie gebruik as gevolg van die aanvullende waarde daarvan met optiese data. Daar is dus 'n groeiende behoefte aan betroubare, akkurate metodes vir die gesamentlike gebruik van SAR en optiese data in landdekking klassifikasies. Die kombinasie van datastelle bring egter ‘n onvermydelike verhoging in data dimensionaliteit mee, en hierdie groot, komplekse datastelle is moeilik om te hanteer. Dus is dit belangrik om die voordele en beperkings van die gebruik van multi-temporale, dubbel-sensor data vir toepassings soos landdekking-klassifikasie te evalueer. Die waarde van gekombineerde (versmelte) RADARSAT-2 en SPOT-5 beelde word in hierdie tesis deur middel van vier eksperimente geevalueer. In Eksperiment 1 is die gebruik van kenmerk seleksie vir dimensionaliteit-vermindering toegepas. Die ranglys van belangrike kenmerke vir beide enkel-sensor en 'n dubbel-sensor data is beoordeel vir vier datums wat oor 'n tydperk van 6 maande strek. Die gemiddelde tekstuur kenmerke uit die optiese lae is konsekwent hoog oor alle datums geplaas. In die twee later datums (29 Mei en 9 Augustus 2014) was die SAR kenmerke meer algemeen, wat dui op die aanvullende aard van SAR en optiese data. SAR data dus gebruik kan word om klasse te onderskei wanneer optiese beelde onvoldoende daarvoor is. Eksperiment 2 het die akkuraatheid van ses gerigte en masjien-leer klassifikasie algoritmes vergelyk om te bepaal watter die beste met hierdie komplekse datastel presteer. Die random gorest klassifikasie algoritme het die hoogste akkuraatheid bereik en is dus in Eksperimente 3 en 4 gebruik. Eksperiment 3 het die voordele van gekombineerde SAR-optiese beelde oor enkel-sensor beelde vir landdekking klassifikasies op vier afsonderlike datums beoordeel. Die versmelte beelde het konsekwent hoër algehele akkuraathede as enkel-sensor beelde gelewer. Die 29 Mei 2014 data het die hoogste akkuraatheid van 69,8% bereik. Die versmelte klassifikasies het ook meer konsekwente resultate oor die vier datums gelewer en die enkel-sensor beelde het tot laer akkuraathede gelei, veral vir die later datums. In Eksperiment 4 is die gebruik van multi-temporale, dubbel-sensor data vir klassifikasie ge-evalueer. Kenmerkseleksie is gebruik om die data stel van 638 potensiële kenmerke na 50 te verminder, wat die beste akkuraatheid van 74,1% gelewer het. Hierdie resultaat bevestig die belangrikheid van multi-temporale data vir grond dekking klassifikasies. Dit bekragtig ook die gebruik van kenmerkseleksie om data vermindering suksesvol te rig sonder om die akkuraatheid van die finale produk te belemmer. Stellenbosch University https://scholar.sun.ac.za vi Multi-temporale en dubbel-sensor data toon potensiaal vir die kartering van landdekking in 'n tropiese, bergagtige streek wat andersins uitdagend sou wees om te karteer met behulp van enkel-sensor data. Oor die algemeen het akkuraathede egter te laag gebly om vir oordraagbaarheid en herhaling van die huidige metode toe te laat. Klassifikasie algoritme optimalisering, gerigte segmentering en verbeterde opleiding data moet oorweeg word om hierdie resultate te verbeter.

Made available in DSpace on 2014-06-11T19:35:45Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-12-10Bitstream added on 2014-06-13T19:25:21Z : No. of bitstreams: 1 mattos_lpv_dr_botfca.pdf: 1675965 bytes, checksum: 3faf029e6aef13589d4485a2b0a651ee (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Penicillium digitatum, agente causador do bolor verde, e Guignardia citricarpa, agente causador da mancha preta, depreciam os frutos citricos. O controle desses patógenos em frutos é realizado com fungicidas sintéticos. Devido a preocupação da sociedade com os riscos de contaminação ambiental, intoxicação humana principalmente infantil e animal e ao surgimento de isolados fúngicos resistentes aos fungicidas sintéticos, estão em desenvolvimento técnicas alternativas aos fungicidas para uma agricultura mais sustentável. O objetivo do trabalho foi avaliar os efeitos de óleos essenciais e fixos e dos agentes de biocontrole no controle de P. digitatum e G. citricarpa em frutos laranja Pêra em pós- colheita. Assim, foram testados os óleos fixos de Allium sativum, Copaifera langsdorffii, Azadirachta indica; e os óleos essenciais de Pogostemon cablin, Mentha arvensis, Eucalyptus spp., Cymbopogon citratus, Ocimum basilicum var. Maria bonita, Romarinus officinalis, Lippia sidoides, Zingiber officinale, Citrus aurantifolia, Piper aduncum e Ocimum basilicum. Além dos óleos, também foram estudados os seguintes agentes de biocontrole: Bacillus subtilis (Serenade®), Bacillus subtilis e Bacillus lichiniformes (Nemix®), Pichia guilliermondii (L29), Sporobolomyces roseus (L41), Rhodotorula mucilagenosa (L17), Sporodiobolus pararoseus, Pichia sp. (L4-1), Debaryomyces hansenii (L62), Pichia membranifaciens (L21) e uma bactéria isolada da laranja. Tanto os agentes de biocontrole, quanto os óleos foram testados in vivo e in vitro contra os dois patógenos. Para a avaliação da atividade dos óleos essenciais e dos antagonistas in vivo, no controle de P. digitatum, foram utilizadas laranjas Pêra. Cada fruto foi ferido em dois pontos opostos, na região equatorial, atingindo a região do albedo. Após o ferimento, os frutos foram inoculados com 20 μL da suspensão de conídios... / Penicillium digitatum, causal agent of green mold, and Guignardia citricarpa causal agent of black spot. Detracts the citrus fruit, the control of these pathogens is made with synthetic fungicides. Due to concern about the risks of environmental contamination, human, mainly children and animal toxicity and the emergence of fungal isolates resistant to fungicides, various researches has been development to obtain alternative techniques for a fungicides. The objectives of this work was to evaluate the effetives fix and essencial oils and biocontrol agents for the control of P. digitatum and G. citricarpa on Pera orange fruits in postharvest. Thus, were tested the fixed oils from Allium sativum, Copaifera langsdorffii, Eucalyptus spp. Azadirachta indica,and the essential oils of Pogostemon cablin, Mentha arvensis, Cymbopogon citratus, Ocimum basilicum var. Maria bonita, Romarinus officinalis, Lippia sidoides, Zingiber officinale, Citrus aurantifolia, Piper aduncum and Ocimum basilicum. In addition were also studied the following biocontrol agents: Bacillus subtilis (Serenade ®), Bacillus subtilis and Bacillus lichiniformes (Nemix ®), Pichia guilliermondii (L29), Sporobolomyces roseus (L41), Rhodotorula mucilagenosa (L17), Sporodiobolus pararoseus, Pichia spp. (L4-1), Derbaryomyces hansenii (L62), Pichia membranifaciens (L21) and a bacterium isolate of the orange. Both biocontrol agents as the oils, were tested in vivo and in vitro against both pathogens. For the assessment of activity of essential oils and antagonists in vivo in controlling P. digitatum were used Pera orange. Each fruit was wounded in two opposite points in the equatorial region, reaching the albedo. After the injury, the fruits were inoculated with 20 mL of conidial suspension of P. digitatum (105 conidia / mL), followed by immersion in a suspension of cells of each biocontrol agent in the concentration: ...(Complete abstract click electronic access below)

Temperature is one of the parameters that limits the output torque and reduces the lifespan of electrical machines. Models that can provide accurate estimation of the temperature field in the most critical components (e.g. windings) at lower computational effort can be useful to improve the design process and reduce the time to market. Depending on the application, engineers usually rely on hi-fidelity models, e.g. based on the finite elements method (FEM), or lower order models, e.g. thermal equivalent circuits (TECs). The aim of the present work is to provide new tools and methodologies to obtain the temperature distribution within the windings using reduced order hi-fidelity models or improved TEC that could account for any working condition, including AC effects. A new methodology, based on the multiple scales method (MSM), is introduced which homogenises the complex windings domain and allows for the estimation of its effective thermal properties. The homogenisation through the MSM is performed solving a single elementary cell. The MSM also allows for the reconstruction of the actual thermal field. Extensive numerical and experimental validation is provided, in particular for the case of electrical windings encapsulated with epoxy. The thermal homogenisation is then combined with an electromagnetic homogenisation technique to estimate winding losses including AC effects, such as proximity and skin effects. The coupled analysis is validated numerically on reference test problems, and experimentally, on a suitably built "motorette". The method is proven to correctly predict losses including thermal effects and to estimate magnitude and location of the temperature hotspot within the winding domain. This work also introduces a new approach for building thermal equivalent circuits that represents the most commonly employed modelling technique for electrical machine thermal analysis. Here the TEC approaches are thoroughly analysed, highlighting limitations. The proposed new technique extends the range of numerical accuracy, accounting for high Biot numbers (up to Bi = 2) and internal heat generation. The result of this approach is higher spatial resolution about the temperature field within the winding domain and thus enables improved information on hotspot location and magnitude. The method is experimentally validated and also applied to model an electrical machine for full-electric in-wheel vehicle propulsion.

In the past two decades a new barley threat has emerged as the disease Ramularia leaf spot (RLS) became more prevalent in temperate regions worldwide. This disease, first identified in the late 19th century, is caused by the filamentous fungus Ramularia collo-cygni (Rcc) and can cause substantial yield losses as well as reduce grain quality. RLS typically occurs late in the growing season and characteristic disease symptoms are usually seen after the crop has flowered. Expression of RLS lesions is thought to be associated with the action of fungal secondary metabolism products. The one group of secondary metabolites (SMs) characterised to date from Rcc, the anthraquinone toxins rubellins, are known to cause necrosis to plant tissues in a non-host specific manner. Therefore, it appears that fungal secondary metabolism might be a key component in understanding the interaction between Rcc and its host. In this study, more than 23 core genes involved in the biosynthesis of SMs belonging to the polyketide and non-ribosomal peptide pathways were identified in the genome of Rcc. Putative clusters containing genes with a predicted function relating to secondary metabolism were identified by in silico genome walking in the genetic loci adjacent to Rcc SM core genes. Two gene clusters containing no SM core gene were also identified. Five of the putative SM clusters exhibited similarity to the known fungal SM biochemical pathways involved in gliotoxin, monodictyphenone, ferricrocin, betaenone and chaetoglobosins biosynthesis. Several gene clusters exhibited similarity to SM clusters from fungal species where the SM pathway is uncharacterised. Changes in transcript abundance of selected SM core genes during RLS development in artificially inoculated barley seedlings were tested. Transcript levels were found to be the highest at an early stage of disease development, typically during the asymptomatic and early lesions formation stages and declined over time, suggesting that the associated SMs in Rcc, may not necessarily be involved in symptoms appearance. The in planta mode of action of the non-host specific photoactivated toxin rubellin D was studied in the model plant Arabidopsis thaliana. Rubellin-induced cell death appeared phenotypically reminiscent of programmed cell death (PCD). Full expression of rubellin D-induced cell death required the host salicylic acid (SA) pathway and the host proteasome supporting the PCD response to this fungal SM. However, a clear correlation between toxin sensitivity and disease susceptibility could not be found, suggesting a potential alternative role for rubellin in disease symptom development.

Resumo: A mancha marrom de alternaria, causada pela Alternaria alternata f. sp. citri, afeta o tangor murcote causando lesões em folhas, ramos e frutos, acarretando em desfolha e manchas que depreciam o fruto comercialmente. Os objetivos deste trabalho foram verificar o efeito do meio de cultura no isolamento, da temperatura e do fotoperíodo no crescimento micelial do patógeno, avaliar a sensibilidade do patógeno à fungicidas in vitro e estabelecer o melhor produto e dose para o controle da doença no campo. As avaliações laboratoriais constaram de avaliações de crescimento micelial, medição do tamanho de conídios, concentração de conídos/mL e avaliação de meios de culturas para isolamento do patógeno. Os resultados do teste in vitro mostraram que os ingredientes ativos trifloxystrobin, iprodione, azoxystrobin, difenoconazole, pyraclostrobin, trifloxystrobin + propiconazole e trifloxystrobin + tebuconazole inibiram completamente o crescimento micelial do patógeno. No ensaio de campo todos os tratamento foram superiores a testemunha quanto a produtividade. Concluindo que o controle da doença é recomendado independente do produto utilizado. Entre os produtos utilizados o tratamento com trifloxystrobin + propiconazole foi rentável comparando-se custo e produtividade. / Abstract: The brown spot caused by Alternaria alternata f. sp. citri, affects the Murcott tangor causing lesions in leaves, branches and fruits, defoliation and depreciating the fruit commercially. The objectives of this work went to determine the influence of temperature, media culture and sensibility several fungicides and rates in vitro and in the field. The results showed that: In in vitro test the ingredients active trifloxystrobin, iprodione, azoxystrobin, difenoconazole, pyraclostrobin, trifloxystrobin + propiconazole and trifloxystrobin + tebuconazole inhibited the micelial growth of the pathogen completely. In the field all fungicides treatments were effectives with productivity. Among the used products the treatment trifloxystrobin + propiconazole was profitable being compared cost and productivity. / Orientador: Edson Luiz Furtado / Coorientador: Wilson Story Venâncio / Banca: Nilton Luiz de Souza / Banca: Maristella Dalla Pria / Mestre

El objetivo general del presente trabajo es poder interpretar un subconjunto del lenguaje de programación AmbientTalk en un dispositivo móvil liviano que sea capaz de interactuar con otros programas desarrollados en AmbientTalk alojados en otros dispositivos que no sean necesariamente del mismo tipo de equipo. El dispositivo móvil liviano usado para esta memoria es un Sun SPOT. El intérprete oficial de AmbientTalk está desarrollado para Java ME CDC, mientras que los Sun SPOT poseen como plataforma de desarrollo Java ME CLDC. Una de las diferencias importantes entre ambos es que tanto reflexión como serialización no están presentes en CLDC, mientras que si lo están en CDC. Ambas son características muy usadas y muy imprescindibles para el intérprete oficial, por lo que se hace necesario replantear un nuevo intérprete para los Sun SPOT. Debido a las capacidades de cómputo limitadas de un Sun SPOT, se decidió separar la plataforma en dos aplicaciones que corren en máquinas distintas: un compilador que lea código fuente AmbientTalk y que genere un archivo binario, y un intérprete AmbientTalk que lea ese archivo binario e interprete el programa almacenado en él en un Sun SPOT. A cada una de las aplicaciones se le realizó un diseño de arquitectura lógica, separando los componentes en módulos semi desacoplados. Luego se realizó una validación al intérprete, realizando para tal efecto una aplicación ejemplo de programación distribuida consistente en un sistema controlador de luces remotas. Se realizó esta aplicación tanto para Java ME CLDC, como para AmbientTalk, mostrando que mientras la aplicación en Java ME CLDC es más eficiente, la aplicación en AmbientTalk fue más simple de desarrollar. Finalmente se concluye que esta plataforma es un paso para tener una implementación de AmbientTalk en toda la gama de dispositivos con Java y que AmbientTalk permite disminuir el tiempo de programación para aplicaciones distribuidas en un Sun SPOT.

O presente trabalho estuda uniões entre chapas de aço DP600 e chapas das ligas de alumínio AA 6181–T4 e AA 5754–H22, obtidas através do processo Friction Spot Welding (FSpW). A soldagem de materiais dissimilares é um dos grandes desafios para a engenharia, pois as propriedades de distintos materiais são muito diferentes na maioria das vezes, o que dificulta a realização deste tipo de união pelos métodos convencionais de soldagem com fusão. O processo FSpW requer menos energia que os processos de soldagem convencionais, não produz fumos, radiação ou resíduos. Permite obter a união de materiais no estado sólido, sendo, portanto potencialmente indicado para uniões dissimilares. Por ser um processo muito mais “limpo” que os usados convencionalmente, pode contribuir significativamente com uma grande preocupação mundial que é a sustentabilidade. A influência de um revestimento galvanizado nas chapas de aço para a qualidade das uniões resultantes foi avaliada realizando-se as operações de soldagem com as chapas de aço nas condições com e sem a camada galvanizada. O método estatístico de Taguchi foi utilizado para definir os parâmetros de soldagem que maximizassem a resistência das juntas para cada condição de ensaio, sendo a qualidade das juntas obtidas definida pela resistência da união ao ensaio de cisalhamento. Durante a soldagem, a temperatura em pontos específicos foi adquirida e, posteriormente, as juntas foram submetidas à análise metalográfica e de composição química por EDS. A partir da análise das macro e microestruturas dos corpos de prova com melhor resistência ao cisalhamento, foi possível associar diferentes parâmetros de processo e mecanismos de união para cada tipo de junta. O estudo comprovou a possibilidade de obtenção de uniões dissimilares entre o aço e as duas ligas de alumínio através do processo FSpW, especialmente quando utilizou-se o aço com a camada galvanizada que apresentou modo de união mais eficaz. / This work aims at the study of welding DP600 steel to AA6181-T4 and AA5754-H22 aluminum alloys plates by Friction Spot Welding (FSpW). Welding of dissimilar materials is a great challenge for engineering due to the diverse properties of different materials, that difficult welding by conventional methods of fusion. FSpW is a joining method that requires lower energy than conventional welding processes and produces no hazard gases or radiation. It allows solid state joining that is potentially indicated to dissimilar materials joining, and contributes significantly to sustainability, because the process can be considered “cleaner” that those used conventionally. The influence of the galvanized layer on the joint performance with the steel plates on was tested using steel plates with and without this coating. The Taguchi statistic method was employed to define the welding process parameters that produce higher shear stress resistance to each test condition, so the welding joints quality was defined based on the union resistance to shear. During the welding operation the temperature at given positions was acquired and the resulting joints were submitted to metallographic and chemical composition analysis. From the analysis of specimen that showed best stress test performance to each joint condition, it was possible to associate different process parameters and joint mechanisms to each condition. The study demonstrates the feasibility of joining the steel to both aluminum alloys using FSpW. The best shear test results were obtained with the presence of a galvanized layer.

Made available in DSpace on 2015-03-26T13:37:45Z (GMT). No. of bitstreams: 1 texto completo.pdf: 704373 bytes, checksum: cce9ca57dac417c0fb3d6c8baa3a4af9 (MD5) Previous issue date: 2010-12-15 / An investigation was carried on observing the potential antagonism of 324 resident bacteria in the phylloplane of collards, grouped in: those producing fluorescent pigments; those forming endospores; and other antagonists. They were tested against alternaria leaf spot, caused by Alternaria brassicicola, and black rot, caused by Xanthomonas campestris pv. campestris. The selection was based on screening tests by means of in vitro and in vivo experiments in a greenhouse using mass selection and confirmation of the potential of biocontrol agents. Ten isolated one were selected for the control of each pathogen. In order to study the mechanism involved in biocontrol, 20 isolated ones were characterized using different mechanisms of antagonism to reduce black rot and alternaria leaf spot. The strain UFV-215 gave the control for Alternaria leaf spot and the isolate UFV-247 for black rot. Both strains were consistent in vitro tests and to reduce both diseases on cabbage. Both bacteria showed efficiency as biocontrol agents against the diseases in greenhouse experiments, showing great potential for utilization under field conditions. / Investigou-se o potencial antagônico de 324 bactérias residentes do filoplano da couve, agrupadas em produtoras de pigmentos fluorescentes, formadoras de endósporo e outras como antagonistas contra Alternaria brassicicola, agente causal da alternariose e Xanthomonas campestris pv. campestris, agente causal da podridão negra das brássicas. A seleção baseou-se em testes de seleção in vitro e experimentos in vivo em casa de vegetação, em duas etapas: seleção massal e confirmação da potencialidade dos agentes de biocontrole. Selecionaram-se dez isolados para o controle de cada patógeno. Para estudar o mecanismo envolvido no biocontrole, caracterizaram-se os 20 isolados em relação a diferentes mecanismos de antagonismo para controlar a alternariose e a podridão negra. Como mais promissores no experimento em casa de vegetação, destacaram-se o isolado UFV-215 para o controle da alternariose e o UFV-247 para o controle da podridão negra. Observou-se que os dois isolados foram compatíveis em testes in vitro e no controle das duas doenças em plantas de couve. Ambas as bactérias selecionadas apresentaram eficiência como agentes de biocontrole contra as doenças em estudo, em experimentos em casa de vegetação, demonstrando grande potencial para utilização no campo.

Trabalho sobre precificação e administração de riscos de derivativos cambiais do mercado brasileiro. / Submitted by Daniel França (danielmusfra@globo.com) on 2010-08-11T21:13:53Z No. of bitstreams: 1 Tese_Daniel_Mussi_100911.pdf: 712586 bytes, checksum: 52ceaf8ea2919c76aead9d97613f6842 (MD5) / Rejected by Gisele Gammaro(gisele.gammaro@fgv.br), reason: Daniel, A cidade e a data é no rodapé da capa e da folha de rosto e não no cabeçalho. on 2010-08-12T18:01:12Z (GMT) / Submitted by Daniel França (danielmusfra@globo.com) on 2010-08-13T17:56:26Z No. of bitstreams: 1 Tese_Daniel_Mussi_100911.pdf: 676227 bytes, checksum: bd55aa471671063df411c7c9a2d1f1a6 (MD5) / Approved for entry into archive by Gisele Gammaro(gisele.gammaro@fgv.br) on 2010-08-13T18:31:52Z (GMT) No. of bitstreams: 1 Tese_Daniel_Mussi_100911.pdf: 676227 bytes, checksum: bd55aa471671063df411c7c9a2d1f1a6 (MD5) / Made available in DSpace on 2010-08-16T13:29:07Z (GMT). No. of bitstreams: 1 Tese_Daniel_Mussi_100911.pdf: 676227 bytes, checksum: bd55aa471671063df411c7c9a2d1f1a6 (MD5) Previous issue date: 2010-05-24 / O objetivo dessa dissertação é apresentar uma documentação detalhada sobre a precificação e administração de riscos dos principais derivativos cambiais negociados no mercado brasileiro. Serão abordadas algumas particularidades desse mercado e serão propostos alguns ajustes à literatura tradicional visando fornecer uma modelagem que seja capaz de quantificar e qualificar corretamente os riscos inerentes a uma carteira de derivativos.