Este trabalho tem por objetivo desenvolver um método de controle de distorção adequado ao design de superfície de produto industrial, com forma tridimensional não planificável, produzido em larga escala, de modo a minimizar as distorções gráficas procedentes da aplicação de uma imagem bidimensional em um objeto tridimensional com superfície não planificável, considerando, principalmente, a complexidade da geometria do objeto. Essa pesquisa justifica-se quando se verifica o aumento de produtos com formas não planificáveis no mercado e a visível dificuldade dos profissionais em resolver problemas de distorções das imagens quando o objeto tem uma geometria complexa. Além disso, o estudo visa contribuir também com a redução de custos de desenvolvimento desse tipo de produto, já que estuda um método que possibilita a verificação digital, eliminando os custos físicos de tentativa e erro. O método utiliza recursos de representação paramétrica de superfícies, que viabilizam a manipulação de objetos tridimensionais complexos no meio computacional e que são definidos por equações que relacionam um domínio paramétrico plano e o espaço tridimensional. Para cada uma das dimensões (x, y e z) do espaço tridimensional, existe uma equação que faz a relação com o espaço paramétrico bidimensional de coordenadas u e v. Dentre esses recursos, os mais utilizados são: mapeamento de textura e render to texture. A indústria de desenhos animados e games tridimensionais costuma utilizar com frequência estes recursos computacionais para melhorar o realismo de suas imagens. Nesta pesquisa, estudase a possibilidade de direcionar essas ferramentas computacionais para a indústria de produtos físicos manufaturados produzidos em série. A pesquisa propõe-se estudar três casos de produtos com superfícies não planificáveis de materiais distintos e processos de produção diferentes entre si. A partir dos três estudos de casos é proposto o método que visa permitir a solução sistematizada dessa classe de problema relacionado às distorções. A verificação do método é realizada, com resultados significativos, em conjunto com três grandes empresas nacionais localizadas da região sul do Brasil. O primeiro estudo de caso consiste em uma tigela de cerâmica da empresa Oxford®; o segundo, uma chaleira de metal da empresa Tramontina®, e o terceiro, uma sandália de polímero da empresa Grendene®. Assim, por meio desta pesquisa, espera-se ampliar a área do conhecimento que circunscreve o design de superfície, ampliando os meios que facilitem a atividade projetual e apontando para a necessidade de instrumentos tecnológicos que venham facilitar os projetos de superfícies de objetos com formas não planificáveis. / This work aims to develop a distortion control method adequate for surface design of mass-produced industrial products with non-planable tridimensional shape, so as to minimize the graphic distortions resulting from the application of a bidimensional image onto a tridimensional object with non-planable surface, taking into consideration mainly the complexity of the object’s geometry. The justification for this research lies in the increase of products with nonplanable shapes available on the market and in the clear difficulty of professionals to solve image distortion problems when the object presents complex geometry. Besides, this research aims to contribute to the reduction of costs of developing this kind of product, seeing that it studies a method that enables digital verification so eliminating the physical costs of trial and error. The method uses resources of parametric representation of surfaces, which enable the manipulation of complex 3D objects in the computational environment, and which are defined by equations that relate one plane parametric domain and the tridimensional space. For each dimension (x, y e z) of the tridimensional space there is an equation that makes the relation with the bidimensional parametric space with coordinates u and v. The most frequently used computational resources are texture mapping and render to texture, which are often used by the industry of 3-D animation to improve the realism of their images. In this work we study the possibility to apply these computational tools in the industry of manufactured products. This research contemplates three case studies of products with non-planable surfaces of different materials and different manufacturing processes. We then propose a method that allows a systematized solution for distortion-related problems. The verification of the method, which showed meaningful results, was carried out together with three large national enterprises located in the southern region of Brazil. The first case study consists in a ceramic bowl by Oxford®; the second, a metal kettle by Tramontina®; and the third, a polymer sandal by Grendene®. With this research we expect to expand the field of knowledge in which surface design is inserted thus extending the resources for the projectual activity and pointing to the need for technological tools that may help with the projects of surfaces of objects with non-planable shape.

Este trabalho tem por objetivo desenvolver um método de controle de distorção adequado ao design de superfície de produto industrial, com forma tridimensional não planificável, produzido em larga escala, de modo a minimizar as distorções gráficas procedentes da aplicação de uma imagem bidimensional em um objeto tridimensional com superfície não planificável, considerando, principalmente, a complexidade da geometria do objeto. Essa pesquisa justifica-se quando se verifica o aumento de produtos com formas não planificáveis no mercado e a visível dificuldade dos profissionais em resolver problemas de distorções das imagens quando o objeto tem uma geometria complexa. Além disso, o estudo visa contribuir também com a redução de custos de desenvolvimento desse tipo de produto, já que estuda um método que possibilita a verificação digital, eliminando os custos físicos de tentativa e erro. O método utiliza recursos de representação paramétrica de superfícies, que viabilizam a manipulação de objetos tridimensionais complexos no meio computacional e que são definidos por equações que relacionam um domínio paramétrico plano e o espaço tridimensional. Para cada uma das dimensões (x, y e z) do espaço tridimensional, existe uma equação que faz a relação com o espaço paramétrico bidimensional de coordenadas u e v. Dentre esses recursos, os mais utilizados são: mapeamento de textura e render to texture. A indústria de desenhos animados e games tridimensionais costuma utilizar com frequência estes recursos computacionais para melhorar o realismo de suas imagens. Nesta pesquisa, estudase a possibilidade de direcionar essas ferramentas computacionais para a indústria de produtos físicos manufaturados produzidos em série. A pesquisa propõe-se estudar três casos de produtos com superfícies não planificáveis de materiais distintos e processos de produção diferentes entre si. A partir dos três estudos de casos é proposto o método que visa permitir a solução sistematizada dessa classe de problema relacionado às distorções. A verificação do método é realizada, com resultados significativos, em conjunto com três grandes empresas nacionais localizadas da região sul do Brasil. O primeiro estudo de caso consiste em uma tigela de cerâmica da empresa Oxford®; o segundo, uma chaleira de metal da empresa Tramontina®, e o terceiro, uma sandália de polímero da empresa Grendene®. Assim, por meio desta pesquisa, espera-se ampliar a área do conhecimento que circunscreve o design de superfície, ampliando os meios que facilitem a atividade projetual e apontando para a necessidade de instrumentos tecnológicos que venham facilitar os projetos de superfícies de objetos com formas não planificáveis. / This work aims to develop a distortion control method adequate for surface design of mass-produced industrial products with non-planable tridimensional shape, so as to minimize the graphic distortions resulting from the application of a bidimensional image onto a tridimensional object with non-planable surface, taking into consideration mainly the complexity of the object’s geometry. The justification for this research lies in the increase of products with nonplanable shapes available on the market and in the clear difficulty of professionals to solve image distortion problems when the object presents complex geometry. Besides, this research aims to contribute to the reduction of costs of developing this kind of product, seeing that it studies a method that enables digital verification so eliminating the physical costs of trial and error. The method uses resources of parametric representation of surfaces, which enable the manipulation of complex 3D objects in the computational environment, and which are defined by equations that relate one plane parametric domain and the tridimensional space. For each dimension (x, y e z) of the tridimensional space there is an equation that makes the relation with the bidimensional parametric space with coordinates u and v. The most frequently used computational resources are texture mapping and render to texture, which are often used by the industry of 3-D animation to improve the realism of their images. In this work we study the possibility to apply these computational tools in the industry of manufactured products. This research contemplates three case studies of products with non-planable surfaces of different materials and different manufacturing processes. We then propose a method that allows a systematized solution for distortion-related problems. The verification of the method, which showed meaningful results, was carried out together with three large national enterprises located in the southern region of Brazil. The first case study consists in a ceramic bowl by Oxford®; the second, a metal kettle by Tramontina®; and the third, a polymer sandal by Grendene®. With this research we expect to expand the field of knowledge in which surface design is inserted thus extending the resources for the projectual activity and pointing to the need for technological tools that may help with the projects of surfaces of objects with non-planable shape.

Through empirical research the researcher gained an in-depth knowledge regarding the growth trends in the South African manufactured export industry as well as the factors determining the patterns of growth and champion industries. Finally, recommendations that may be used by relevant authorities and scholars were made. To researchers, a study at disaggregated level into the growth trends of each manufactured export sub-sector should be central to future research. / Dissertation (MA (Economics))--University of Pretoria, 2005. / Economics / unrestricted

Magister Commercii - MCom / The purpose of this study was to evaluate econometrically the effects of real exchange rate misalignment on South African exports between the period 1994 and 2015 using quarterly time-series data. Cointegration tests were done using the Johansen and Juselius approach. The study examined the effects of real exchange rate misalignment of the rand on South Africa’s exports, namely manufactured goods exports, automotive and chemical exports, mining exports, machinery and transport equipment exports and agricultural exports, on both an aggregate and a sectoral level. The long run impact of real exchange rate misalignment on total exports was found to be negative and significant, implying that real exchange rate misalignment negatively affects exports. In the short run, misalignment of the currency was found to enhance export growth and is not sustainable in the long run. On the sectoral level, the study found that in the long run exports are influenced by real exchange rate misalignment with varying sensitivity. Manufactured goods exports, automotive and chemical exports and machinery and transport equipment exports are all negatively affected by real exchange rate misalignment. On the contrary, mining exports and agricultural exports are positively affected by real exchange rate misalignment. Therefore, if an export-led growth path is envisaged for the South African economy, it is important for monetary and fiscal policy to be conducted in such a manner that ensures stability in the real exchange rate at an appropriate level. This will ultimately aid export competitiveness for South Africa. Based on the findings of this study, the researcher recommends that misalignment of the currency should be avoided at all costs.

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SammanfattningDet här projektet behandlar området Additiv Tillverkning (AM) för metalliska material och undersöker om det är lämpligt att använda vid produktion inom flygindustrin. AM är en relativt ny tillverkningsmetod där föremål byggs upp lager för lager direkt ifrån en datormodell. Teknikområdet tillåter i många fall större konstruktionsfriheter som möjliggör tillverkning av mer viktoptimerade och funktionella artiklar. Andra fördelar är materialbesparing och kortare ledtider vilket har ett stort ekonomiskt värde.En omfattande litteraturstudie har gjorts för att utvärdera alla tekniker som finns på marknaden och karakterisera vad som skiljer de olika processerna. Även maskiners prestanda och kvalité på tillverkat material utvärderas, och för varje teknik listas möjligheter och begränsningar. Teknikerna delas grovt upp i pulverbäddsprocesser och material deposition-processer. Pulverbäddsteknikerna tillåter större friheter i konstruktion, medan material deposition-processerna tillåter tillverkning av större artiklar. Den vanligaste energikällan är laser som ger ett starkare men mer sprött material än de alternativa energikällorna elektronstråle och ljusbåge.Två specifika tekniker har valts ut för att undersöka närmare i detta projekt. Electron Beam Melting (EBM) från Arcam och Wire fed plasma arc direct metal deposition från Norsk Titanium (NTiC). EBM är en pulverbäddsprocess som kan tillverka färdiga artiklar i begränsad storlek då låga krav ställs på toleranser och ytfinhet. NTiC använder en material deposition-process med en ljusbåge för att smälta ner trådmaterial till en nära färdig artikel. Den senare metoden är mycket snabb och kan tillverka stora artiklar, men måste maskinbearbetas till slutgiltig form. En materialundersökning har genomförts där Ti6Al4V-material från båda teknikerna har undersökts i mikroskop och testats för hårdhet. För EBM-material har även ytfinhet och svetsbarhet undersökts då begränsad byggvolym i många fall kräver fogning. Materialen har egenskaper bättre än gjutet material med avseende på styrka och duktilitet, men inte lika bra som valsat material. Provning visar att skillnaden på mekaniska egenskaper i olika riktningar är liten även fast materialet har en inhomogen makrostruktur med kolumnära korn i byggriktningen. EBM ger en finare mikrostruktur och ett starkare material och, tillsammans med de ökade konstruktionsfriheterna, så är det den tekniken som är bäst lämpad för flygplansartiklar då svetsbarheten är god och det finns möjlighet att bearbeta ytan till slutgiltigt krav.Nyckelord: Additiv Tillverkning, Flygteknik, Titan / AbstractThis project treats Additive Manufacturing (AM) for metallic material and the question if it is suitable to be used in the aeronautics industry. AM is a relatively new production method where objects are built up layer by layer from a computer model. The art of AM allows in many cases more design freedoms that enables production of more weight optimized and functional articles. Other advantages are material savings and shorter lead times which have a large economic value.An extensive literature study has been made to evaluate all techniques on the market and characterize what separates the different processes. Also machine performance and material quality is evaluated, and advantages and disadvantages are listed for each technique. The techniques are widely separated in powder bed processes and material deposition processes. The powder bed techniques allow more design freedom while the material deposition techniques allow production of large articles. The most common energy source is laser that gives a harder and more brittle material than the alternative energy sources electron beam and electric arc.Two specific techniques have been selected to investigate further in this project. Electron Beam Melting (EBM) from Arcam and Wire fed plasma arc direct metal deposition from Norsk Titanium (NTiC). EBM is a powder bed process that can manufacture finished articles in limited size when no requirements are set on tolerances and surface roughness. NTiC uses a material deposition process with electric arc to melt wire material to a near-net shape. The latter method is very fast and can produce large articles, but have to be machined to finished shape. A material investigation have been made where Ti6Al4V-material from both techniques have been investigated in microscope and tested for hardness. For the EBM-material have also surface roughness and weldability been investigated since the limited building volume often requires welding. The materials have mechanical properties better than cast material with respect to strength and ductility, but not as good as wrought material. Test results show that the difference in mechanical properties in different directions is small, even though the material has an inhomogeneous macrostructure with columnar grains in the building direction. The EBM-material has a finer microstructure and a stronger material and, in combination with improved design freedom, this technique is most suitable for aerospace articles when the weldability is good and it is possible to surface work where requirements of the surface roughness are set.Keywords: Additive Manufacturing, Aeronautics, Titanium

Properly dried sweet cream buttermilk, because of its high fat and lecithin contents, should make superior ice cream. Its use as a source of serum solids in ice cream. Its use as a source of serum solids in ice cream mix would open an outlet for this butter by-product and would serve the needs of ice cream manufacturers during nonfat dry milk solids shortage and it may make a higher score ice cream. The demand for milk solids shortage and it may make a higher score ice cream. The demand for milk solids has been increasing so rapidly that today the by-products of the dairy industry are being utilized as sources of human food to a much greater extent than before. In past years the greater bulk of creamery buttermilk has been utilized as animal feeds. Attempts are being made to convert more of this by-product into channels of human consumption. As the manufacture of sweet cream butter is increasing at a rapid pace, a larger supply of buttermilk product of high quality which is fit for human consumption is available in the market. Many previous investigators have used buttermilk products as a source of serum solids in ice cream mix with favorable results. The advantage claimed has been that it tends to improve the whipping ability of ice cream mixes and to impart richer flavor to the product. These beneficial qualities have been attributed to the butterfat and the phospholipids, of which lecithin is predominant. The work of Chapman and Supplee shows that buttermilk and cream contins several times as much licithin as skimmilk. The amounts of total phospholipids reported by Holm et al and Wright et al are approximately 1.77 per cent in dry buttermilk and 1.06 per cent in dry skim milk.

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No description available.

A detailed code verification study of an unstructured finite volume Computational Fluid Dynamics (CFD) code is performed. The Method of Manufactured Solutions is used to generate exact solutions for the Euler and Navier-Stokes equations to verify the correctness of the code through order of accuracy testing. The verification testing is performed on different mesh types which include triangular and quadrilateral elements in 2D and tetrahedral, prismatic, and hexahedral elements in 3D. The requirements of systematic mesh refinement are discussed, particularly in regards to unstructured meshes. Different code options verified include the baseline steady state governing equations, transport models, turbulence models, boundary conditions and unsteady flows. Coding mistakes, algorithm inconsistencies, and mesh quality sensitivities uncovered during the code verification are presented. In recent years, there has been significant work on the development of algorithms for the compressible Navier-Stokes equations on unstructured grids. One of the challenging tasks during the development of these algorithms is the formulation of consistent and accurate diffusion operators. The robustness and accuracy of diffusion operators depends on mesh quality. A survey of diffusion operators for compressible CFD solvers is conducted to understand different formulation procedures for diffusion fluxes. A patch-wise version of the Method of Manufactured Solutions is used to test the accuracy of selected diffusion operators. This testing of diffusion operators is limited to cell-centered finite volume methods which are formally second order accurate. These diffusion operators are tested and compared on different 2D mesh topologies to study the effect of mesh quality (stretching, aspect ratio, skewness, and curvature) on their numerical accuracy. Quantities examined include the numerical approximation errors and order of accuracy associated with face gradient reconstruction. From the analysis, defects in some of the numerical formulations are identified along with some robust and accurate diffusion operators. / Ph. D.