Essen, Univ., Diss., 2000. / Computerdatei im Fernzugriff.

Duisburg, Universiẗat, Diss., 1997.

Zugl.: Berlin, Techn. Univ., Diss., 2004.

Hannover, Universiẗat, Diss., 2004.

Essen, Universiẗat, Diss., 2000.

Carbon is a necessary reductant in steel production to convert iron ore to metallic iron. The use of coal and coke causes CO2 emissions to be released into the environment. Using bio-based carbon sources has the potential to offset these emissions and reduce cokemaking overall carbon footprint. The use of biomaterial in coal blends reduces the fossil fuel requirements but to what capacity and type of biocarbon can replace coal is unknown. The full effects of coal and coke characterization from the addition of biomaterial are unknown. In this work, raw biomaterials available to industrial users were evaluated for substitution at low amounts in operational coal blends. Physically, the optical properties of carbon coke forms can provide insight into the strength, reactivity, and performance in the blast furnace, resulting from coal rank and type. The interaction of the biomaterial substitutions with coal during the coking process is evaluated to better understand the reduction in coke strength after reaction (CSR). For this purpose, a series of the pilot oven and sole heated oven tests were performed. When coal was substituted with low amounts of raw biomaterials, the most notable changes in coke texture analysis were to incipient and circular textures. In this work, data from a series of pilot oven and sole heated oven tests showed that fine coke textures and overall inerts increased. The changes in coke textures can be linked to decreases in coke strength after reaction (CSR). / Thesis / Master of Applied Science (MASc) / Metallurgical coke remains the main fuel and reductant source for ironmaking by blast furnace operation. Quality metallurgical coal, a fossil fuel, is required to produce coke. This work continues ongoing steel industry research investigating biomaterial substitution of coal as a more sustainable option. Coal is considered a new release of greenhouse gas (GHG) emissions when used in the steelmaking process compared to a biomaterial which is regarded as a GHG neutral replacement. Three raw biomaterials, available to industrial users, were evaluated for substitution at low amounts and compared to an operational coal blend. The substitution could allow for GHG emissions of the cokemaking processes to be reduced if quality coke can be produced. The interaction of the biomaterial substitutions with coal during the coking process is evaluated in this work to better understand the resultant coke textures related to reduction in coke strength from the substitution.

Blend recognition and suppression from a tessellated model is important in applications such as model simplification in analysis and collaborative design where tessellated models are being used. This could also be used to pre-process the model before attempting to recognize form features in it. A procedure is described for recognizing and subsequently suppressing blends (fillets/rounds) in a tessellated model of a part. Earlier efforts on recognizing secondary features such as blends have used the boundary representation (B-Rep) of the part as input. Blend recognition and suppression from a tessellated model has not been addressed to the best of our knowledge. There has been work reported on the related problem of segmentation of tessellated surfaces. Segmentation refers to the decomposition of the object into regions where the underlying surfaces having similar characteristics. The segmented surface may be of any of surface like plane surface. There are two broad approaches to segmentation - vertex-based and edge-based. The vertex-based method clusters triangles consisting of connected vertices having the same attribute. One drawback of this method is that the boundaries of the clustered regions are not clearly defined due to difference in the labels of contiguous vertices. The edge-based method is based upon the dihedral angle at each edge in the tessellated model. The main drawback of this method is that edges in the boundary of the segmented patches are disconnected. This will result in an incomplete bounding loop when used for recognizing features. Smooth transitions at the boundary of features cannot be trapped with this approach. These techniques cannot be therefore used for recognizing blends. There have been efforts to recognize and suppress blends in a B-Rep model. Suppressing blend features in a B-Rep model is easier (compared to suppression from tessellated model) because smooth edges provide a clue to presence of blends. In the case of a tessellated model, the bounding loop of blends will not consist of smooth edges and no explicit signature is available for blends. In B-Rep model, information about the radius of blend is also available while this is not directly available in a tessellated model. Constant radius blends meet the requirements of most blending features encountered in mechanical part design. The surfaces forming a constant radius blend may be classified as cylindrical, spherical and toroidal surfaces. Spherical blend is formed by a blending operation at a vertex at which either three concave linear edges or three convex linear edges are incident. Blending operation on a linear edge forms cylindrical blend. Toroidal blend is formed by a blending operation on a circular edge. This circular edge may be closed (end vertices are identical) or open. Toroidal blend is also formed at a vertex at which at least one convex and one concave edge is incident. So toroidal blend can be classified into closed toroidal blend, open toroidal blend and vertex toroidal blend. In recognition process, for every triangle, cylindrical, spherical and toroidal surface parameters are calculated. In the second step, triangles having same surface parameters are clustered. The cluster of triangles are then classified as a blend or a form feature. Finally, toroidal blends are classified as one of the three types of toroidal blend. Procedures for the suppression of edge cylindrical blend and edge toroidal blend are described. At the present time, vertex blends are not suppressed individually. Rather in the process of suppressing edge blends, vertex blends are also suppressed. The parent surfaces that were blended are identified using the bounding loops of the blends. Triangles in the blend are then deleted and the parent surfaces are extended to suppress the feature. The key issues in suppression are - identification of all the surfaces at the blend, identification of the entities that were blended (edges and vertices) and updating the tessellated model. Results of constant radius blend recognition and suppression, on benchmark parts from NIST design repository are presented. This is followed by a discussion on the correctness of the recognition procedures. The thesis concludes by summarizing the contributions and identifies the following are as recognition of variable radius blends, blends on non-linear surfaces, suppression of all small volumetric feature as areas for further research.

A indústria de pet food cresce juntamente com as pesquisas nessa área com os objetivos não apenas de atender as necessidades nutricionais, mas também, com o propósito de promover saúde, bem estar e longevidade aos animais de companhia. Portanto, objetivou-se avaliar os efeitos de suplementos promotores de saúde intestinal sobre a digestibilidade dos nutrientes, produtos fermentativos e parâmetros imunológicos em cães adultos. Foram utilizados 24 cães adultos de diferentes pesos e portes, divididos em seis blocos casualizados e, distribuídos aleatoriamente nos tratamentos [(CO) controle, sem adição de prebiótico; (GOS) inclusão de 1,0% de galactooligossacarídeos; (B1) inclusão de 0,5% de um blend de prebióticos; (B2) inclusão de 1,0% de um blend de prebióticos\"]. O experimento foi constituído de 30 dias, sendo os 20 primeiros de adaptação aos tratamentos e os últimos 10 dias de coletas de fezes e sangue. Os dados obtidos foram analisados no programa SAS. Foram previamente verificadas normalidade dos resíduos e homogeneidade das variancias, em seguida os dados foram submetidos a teste de ANOVA, por fim as médias foram comparadas pelo teste de Tukey ao nível de significância de 5%. A suplementação dos prebióticos não alterou os coeficientes de digestibilidade aparente testados, produção e escore fecal (p>0,05). Em relação aos produtos de fermentação avaliados, a adição dos promotores de saúde intestinal não alterou o pH fecal, nem as concentrações de amônia, ácido lático, ácido acético, ácido propiônico e ácido butiríco, ácidos graxos de cadeia curta (AGCC) totais, ácido valérico, ácido iso-butírico e ácidos graxos de cadeia ramificada (AGCR) totais das fezes (p>0,05). No entanto, a adição de GOS diminuiu a concentração do AGCR isovalérico (p=0,0423) em relação a B1. Quanto aos parâmetros imunológicos avaliados, a adição de GOS e B2 aumentou o número total de células polimorfonucleares, assim como o burst oxidadivo em relação aos tratamentos B1 e CO (p<0,0001). O tratamento B2 melhorou o índice de fagocitose de S. aureus em relação ao CO, porém não diferiu dos demais (p=0,011). No teste de fagocitose de E.coli, os tratamentos GOS e B2 apresentaram melhor índice do que o tratamento CO, o qual não diferiu de B1 (p=0,0067). Pode-se concluir que os tratamentos GOS e Blend Yes Golf, quando incluídos a 1,0% na formulação do alimento, aumentaram a atividade fagocitária e o burst oxidativo de cães saudáveis. / The pet food industry grows along with research in this area with the goals not only of meeting nutritional needs but also with the purpose of promoting health, well-being and longevity to companion animals. The objective of this study was to evaluate the effects of intestinal health promoting supplements on nutrient digestibility, fermentative products and immunological parameters in adult dogs. Twenty-four adult dogs were divided into six blocks and randomly assigned to the treatments [ a control treatments, without prebiotics (CO); inclusion of 0.5% a prebiotic blend Yes Golf (B1); inclusion of 1.0.% galactooligosaccharide (GOS); inclusion of 1.0% a prebiotic blend Yes Golf (B2)], following a randomized block design. The experiment consisted of 30 days, being the first 20 of adaptation to the treatments and the last 10 days of collections of feces and blood. The results were analyzed for their normality and the means were compared by the Tukey test at the significance level of 5.0%. Prebiotic supplementation had no effect on the apparent digestibility coefficients tested, yield and fecal score (p> 0.05). For the fermentation products evaluated, the addition of the intestinal health promoters did not alter the fecal pH, nor the concentrations of ammonia, lactic acid, short chain fatty acids (SCFA) and most faecal branched chain fatty acids (BCFA) (p> 0.05). The addition of GOS decreased the concentration of iso-valeric fatty acid (p = 0.0423). Regarding the immunological parameters evaluated, the addition of GOS and B2 increased the total number of polymorphonuclear cells, as well as the oxidative burst in relation to the treatments B1 and CO (p <0.0001). Treatment B2 improved the rate of S. aureus phagocytosis in relation to CO, but did not differ from the others, and treatments B1 and GOS did not differ from CO (p = 0.0111). For E.coli phagocytosis, the GOS and B2 treatments had a better index than the CO treatment, which did not differ from B1 (p = 0.0067). It can be concluded that GOS and B2, when included 1.0% in the formulation of the food, seem to present prebiotic potential regarding the immunity of healthy dogs.

We have prepared a new class of polybenzoxazine based nanocomposites through DNA-like self-complementary multiple hydrogen bonding. At first, benzoxazine containing thymine (Bz-T), PEO containing adenine (PEO-A) group and POSS containing adenine (POSS-A) have been successfully synthesized, respectively. Those chemical structures were confirmed by 1H and 13C NMR and FT-IR spectroscopies. DSC and TGA analyses showed that the Bz-T had lower cross-link temperature and higher thermostability than benzoxazine containing methyl acrylate (BZ-ac) group. Moreover, TEM and WAXD provided a new evidence for linearly structure and self-assembly polybenzoxaine through self-complementary multiple hydrogen bonding of its T units. Then, PEO-A/PBz-T and POSS-A/PBz-T hybrid materials were prepared. SAX, WAXD, TEM and AFM analyses indicated that the size of PEO domain in PBz-T matrix was significantly decreased and the new type phase separation boundary (discrete domain through non-convent bonds) was obtained. Finally, we were using WAXD, TEM, DSC and nanoindenter to study properties of POSS-A/PBz-T nanocomposite. The presence of self-assembly nano-lamellate structure and enhance the mechanical properties on thin film, because of well-dispersion of POSS in PBz-T matrix through strong hydrogen bonding between A-T interactions.

Zugl.: Dresden, Techn. Univ., Diss., 2004.