Orientador: Carlos Gilberto Raetano / Resumo: Fungicidas multi-sítio, a exemplo do mancozebe tem sido cada vez mais utilizados no controle da ferrugem da soja (Phakopsora pachyrhizi) e como estratégia anti-resistência aos fungicidas de sítio de ação único, amplamente utilizados na agricultura. Dessa maneira, buscou-se entender como a tecnologia de aplicação por meio da redução da taxa de aplicação e pelo uso de adjuvantes podem influenciar no controle da doença causada por Phakopsora pachyrhizi, quando associada ao fungicida mancozebe. Para isso, no capitulo 1, o objetivo foi avaliar a retenção foliar do fungicida de contato mancozebe em diferentes formulações na interação com adjuvantes em folhas de soja. No capítulo 2, o objetivo foi avaliar o controle da ferrugem da soja sob variação da taxa de aplicação de mancozebe em mistura com adjuvantes. Para a superfície adaxial a formulação GD apresenta maiores volumes de líquido retido enquanto que para a superfície abaxial, em geral, a formulação não apresenta interferência significativa. No geral, maior retenção da calda foi constatada na superfície abaxial do folíolo de soja, com destaque para caldas fungicidas contendo o polímero natural J-S e o óleo mineral Argenfrut. A redução da taxa de aplicação para 50 L ha-1 e a associação do fungicida mancozebe com adjuvantes pode influenciar a severidade da ferrugem da soja, contudo, de maneira geral, se considerar apenas a redução da taxa de aplicação, de 120 L ha-1 para 50 L ha-1, não há interferência no controle da doença, prin... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Multi-site fungicides as mancozebe has been increasingly used to control soybean rust (Phakopsora pachyrhizi) and as an anti-resistance strategy to single-site fungicides, widely used on agriculture. Thus, this study aimed a better understanding on how the application technology through the reduction of application rate and the use of adjuvants can influence on the control of the disease caused by Phakopsora pachyrhizi, in association with the fungicide mancozeb. To do so, on chapter 1 the study aimed to evaluate the foliar retention of mancozeb fungicide, in the WP and WG formulations, mixed with adjuvants on soybean leaves. On chapter 2, the aim of this study was to evaluate the soybean rust control under different volume rates of mancozeb spraying mixed with adjuvants. On the adaxial surface, the WG formulation has higher volumes of liquid retained while for the abaxial surface, in general, the formulation does not present significant interference. In most cases, greater retention of the spray mixture was found on the abaxial surface of the soybean leaflet, with emphasis on those containing the natural polymer J-S and the mineral oil Argenfrut. The reduction of the application rate to 50 L ha-1 and the association of the fungicide mancozebe with adjuvants can influence the severity of soybean rust, however, in general, if we consider only the reduction of the application rate, of 120 L ha-1 to 50 L ha-1, there is no interference in disease control, especially in early stag... (Complete abstract click electronic access below) / Mestre

For this master thesis, two methods to apply a pattern with a controlled amount of moisture to hand sheets were evaluated. The two methods evaluated were spraying and pressing. Spraying moisture onto the sheets was deemed the easiest method to control and was chosen for further studies. The sheets were sprayed with four spray times and patterns to create different moisture content variations (4.2, 8.0, 14.2 and 26.9 pp moisture content difference). The moisture patterns were designed so the sheets had either moist spots with drier surroundings or reversibly, drier spots with moist surroundings. The sprayed sheets were dried unrestrained or fully restrained to study how in-plane moisture variations could affect paper properties and out-of-plane deformation. Unrestrained drying resulted in out-of-plane deformation around the areas where moisture had been applied. Restrained drying resulted in no out-of-plane deformation but instead changes in opacity, permeance, grammage and thickness occurred. The severity of cockling and difference in paper properties after drying were found to increase with greater moisture content variation before drying. However all effects could be obtained even at the lowest moisture content variation. The resulting out-of-plane deformation varied between ±100 μm for 4.2 pp moisture content difference and ±250 μm for 14.2 pp moisture content difference

There is lack of evidence on which of the two highly recommended malaria prevention methods, insecticide treated bednets and indoor residual spraying, is more effective than the other. There is also limited peer reviewed literature that compares the characteristics of people who use the two malaria prevention methods. Based on the Health Belief Model, the research questions tested whether there is any relationship between the use of mosquito bednet or the use of indoor residual spraying and contracting malaria, and whether there is any relationship between sociodemographic and socioeconomic factors and the use of malaria prevention methods. Using a quantitative research design, secondary data from the 2011 Angola malaria indicator survey were analyzed. Chi-square for association, logistic regression, and multinomial logistic regression tests were used. There was no statistically significant association between the use of mosquito bednet and having malaria. However, the use of indoor residual spraying significantly reduced the likelihood of getting malaria. There was also a statistically significant association between place of residence, wealth index, level of education, and number of household members and using mosquito bednet and between wealth index and using indoor residual spraying. In conclusion, the malaria prevention programs should focus on indoor residual spraying. It is recommended that all households in southern Africa malaria prone areas should be regularly sprayed. The findings of this study contribute to positive social change in the sense that by using more effective malaria prevention method, individuals will be able to function normally on daily basis, save on expenses related to employment loses or treatment and care of the sick, as well as loss of life and improve own economic status.

A method is described for ultrasonically spraying thin films of carbon nanotubes that have been suspended in organic solvents. Nanotubes were sonicated in N-Methyl-2-pyrrolidone or N-Cyclohexyl-2-pyrrolidone and then sprayed onto a heated substrate using an ultrasonic spray nozzle. The solvent quickly evaporated, leaving a thin film of randomly oriented nanotubes. Film thickness was controlled by the spray time and ranged between 200-500 nm, with RMS roughness of about 40 nm. Also described is a method for creating thin (300 nm) conductive freestanding nanotube/polymer composite films by infiltrating sprayed nanotube films with polyimide.

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No description available.

No / This study investigates the effect of heat treatment on changes in microstructure and wear behaviour of WC-NiCr coatings. Two feedstock powders with a similar chemical composition and different particle sizes (near nano-structured WC-17NiCr and microstructured WC-15NiCr) were used. High-velocity oxyfuel spraying technique was used to deposit coatings on to a mild steel substrate using identical spraying parameters. Coated samples were then heat treated in a nitrogen atmosphere at 500 and 700°C. The effect of heat treatment on changes in hardness and wear performance of the coatings was studied using microstructural analysis, micro-hardness indentation and abrasive wear tests. The results showed that the heat treatment increased the hardness of both coatings and a corresponding increase in wear resistance was recorded. The formation of a brittle CrWO4 phase in the microstructured coating resulted in brittle fracture of the coating and this gave lower wear resistance compared to the nanostructured coatings.

M.S.

The research work performed in this thesis has been carried out at the Production Tech-nology Centre where the Thermal Spray research group of University West has its work-shop and labs. This research work has been performed in collaboration with the International Advanced Research Centre for Powder Metallurgy and New Materials (ARCI), Hyderabad, India. First of all, I would like to express my sincere thanks and gratitude to my supervisors Dr. Nicolaie Markocsan and Dr. Nicholas Curry for their guidance, great support and valuable suggestions without which this work could not have been possible. I would also like to thanks Prof. Per Nylén for keeping faith in me and providing me an opportunity to work at PTC, which is a great place to perform research. It is my pleasure being their student and I wish I would keep learning from all of them, both on academic and personal grounds. I would also like to thank my colleagues at PTC Mr. Mohit Gupta and Mr. Stefan Björklund, for their help and support during this work. I would like to acknowledge the H.C. Starck Company for its financial support for the pro-ject; Dr. Filofteia-Laura TOMA at Fraunhofer IWS, Dresden to help us in spraying suspen-sion sprayed YSZ top coats, G Shivkumar from ARCI to help us in spraying solution pre-cursor sprayed top coats and Toni Bogdanoff, Jönköping University to help us in conduct-ing the LFA experiment

Thermal barrier coating (TBC) systems are widely used on gas turbine components to provide thermal insulation and oxidation protection. TBCs, incombination with advanced cooling, can enable the gas turbine to operate at significantly higher temperatures even above the melting temperature of the metallic materials. There is a permanent need mainly of environmental reasons to increase the combustion turbine temperature, hence new TBC solutions are needed.By using a liquid feedstock in thermal spraying, new types of TBCs can be produced. Suspension plasma/flame or solution precursor plasma spraying are examples of techniques that can be utilized for liquid feedstock thermal spraying.This approach of using suspension and solution feedstock, which is an alternative to the conventional solid powder feed stock spraying, is gaining increasing research interest, since it has been shown to be capable of producing coatings with superior coating performance.The objective of this research work was to explore relationships between process parameters, coating microstructure, thermal diffusivity and thermal conductivity in liquid feedstock thermal sprayed TBCs. A further aim was to utilize this knowledge to produce a TBC with lower thermal diffusivity and lower thermal conductivity compared to state-of-the-art in industry today, i.e. solid feed stock plasma spraying. Different spraying techniques, suspension high velocity oxy fuel,solution precursor plasma and suspension plasma spraying (with axial and radialfeeding) were explored and compared with solid feedstock plasma spraying.A variety of microstructures, such as highly porous, vertically cracked and columnar, were obtained. It was shown that there are strong relationships between the microstructures and the thermal properties of the coatings.Specifically axial suspension plasma spraying was shown as a very promising technique to produce various microstructures as well as low thermal diffusivity and low thermal conductivity coatings.