Avaliação dos parâmetros tempo, corrente e pressão na soldagem por resistência elétrica de compósitos PEI/fibras contínuas: influência na resistência mecânica

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Supercritical carbonation treatment on extruded fibre-cement reinforced with vegetable fibres

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effect of the particle size of maize, rice, and sorghum in extruded diets for dogs on starch gelatinization, digestibility, and the fecal concentration of fermentation products

The influence of rice, maize, and sorghum raw material particle size in extruded dry dog food on the digestibility of nutrients and energy and the fecal concentration of fermentation products was investigated. Three diets with similar nutrient compositions were formulated, each with 1 starch source. Before incorporation into diets, the cereals were ground into 3 different particle sizes (approximately 300, 450, and 600 mu m); therefore, a total of 9 diets were in a 3 x 3 factorial arrangement (3 cereals and 3 particle sizes). Fifty-four beagle dogs (12.0 +/- 0.1 kg BW) were randomly assigned to the diets, with 6 dogs per diet. The digestibility was measured with the chromium oxide method. The data were evaluated with ANOVA considering the carbohydrate source, grinding effect, and interactions. The means were compared with the Tukey test and polynomial contrasts (P < 0.05). With the same grinding procedure, rice was reduced to smaller particles than other cereals. The cereal mean geometric diameter (MGD) was directly related to starch gelatini-zation (SG) during extrusion. For rice diets, the MGD and SG did not change nutrient digestibility (P > 0.05); only GE digestibility was reduced at the largest MGD (P < 0.01). For maize and sorghum diets, the total tract apparent nutrient digestibility was reduced for foods with greater MGD and less SG (P < 0.01). A linear reduction in nutrient digestibility according to cereal particle size was observed for sorghum (r(2) < 0.72; P < 0.01). Higher concentrations of fecal total shortchain fatty acids (SCFA) were observed for sorghum diets (P < 0.05) than for other diets. The rice diets led to the production of feces with less lactate (P < 0.05). The increase in raw material MGD did not influence fecal SCFA for rice diets, but for the dogs fed maize and sorghum foods, an increase in propionate and butyrate concentrations were observed as MGD increased (P < 0.05). In conclusion, for dogs fed different particle sizes of the cereal starches in the extruded diets, the digestibility and fecal characteristics were affected, and this effect was ingredient dependent.

Thermal degradation and lifetime estimation of poly(ether imide)/carbon fiber composites

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Influence of water immersion and ultraviolet weathering on mechanical and viscoelastic properties of polyphenylene sulfide-carbon fiber composites

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Strategies to improve the mechanical properties of starch-based materials: plasticization and natural fibers reinforcement

Biodegradable polymers are starting to be introduced as raw materials in the food-packaging market. Nevertheless, their price is very high. Starch, a fully biodegradable and bioderived polymer is a very interesting alternative due to its very low price. However, the use of starch as the polymer matrix for the production of rigid food packaging, such as trays, is limited due to its poor mechanical properties, high hidrophilicity and high density. This work presents two strategies to overcome the poor mechanical properties of starch. First, the plasticization of starch with several amounts of glycerol to produce thermoplastic starch (TPS) and second, the production of biocomposites by reinforcing TPS with promising fibers, such as barley straw and grape waste. The mechanical properties obtained are compared with the values predicted by models used in the field of composites; law of mixtures, Kerner-Nielsen and Halpin-Tsai. To evaluate if the materials developed are suitable for the production of food-packaging trays, the TPS-based materials with better mechanical properties were compared with commercial grades of oil-based polymers, polypropylene (PP) and polyethylene-terphthalate (PET), and a biodegradable polymer, polylactic acid (PLA).

Bladder augmentation in rabbits with anionic collagen membrane, with or without urotelial preservation. Cistometric and hystologic evaluation

The use of bowel segments to perform bladder augmentation is associated with several metabolic and surgical complications. A great variety of synthetic materials, biodegradable or not, have been tested. Collagen-based biomaterials have shown effectiveness for the regeneration and obtainment of a functional bladder. Assess the functional and histological response of the rabbit bladder to anionic collagen membrane (ACM), either when it is anastomosed to the bladder or it is placed onto bladder after vesicomyectomy. In 15 male rabbit a partial cystectomy was performed. After 4 weeks they were divided in 3 groups. Group 1 (G1) - bladder augmentation with ACM. Group 2 (G2) ACM is placed onto bladder after vesicomyectomy. Group 3 (G3) control group. Maximal bladder capacity (MBC) and weight were assessed with 4 (M1), 8 (M2) and 12 (M3) weeks after partial cystectomy. In M3 was performed the sacrifice and extraction of the bladder and kidneys for anatomopathologic study. There were neither bladder stones, nor implant extrusion in M3. There was a significant increase in MBC in G1 and G2 (p<0.05), but no statistical differences in G3 (p=0.35). There is no significant difference comparing G1 and G2. In M3, both groups have shown a bigger MBC than G3 (p<0.05). The microscopic assessment showed an inflammatory reaction in the bladder augmented, with urothelium preserved. The ACM was effective for the increase of MBC. The bladders with preservation of the urothelium have shown an extensive inflammatory process.

Análise da biocompatibilidade de cones de biovidro e biovitrocerâmico (Biosilicato®) em cavidade eviscerada de coelho

OBJETIVO: Avaliar experimentalmente a biocompatibilidade de cones de biovidro e biovitrocerâmico em cavidades evisceradas de coelhos. MÉTODOS: Foram utilizados 45 coelhos albinos submetidos à cirurgia de evisceração do olho direito, seguida da inclusão de cones de biovidro e dois tipos de biovitrocerâmicos (chamados de FI e FII) na cavidade escleral. Os animais foram sacrificados em três momentos (7, 90 e 180 dias). Os parâmetros avaliados foram: peso, exame clínico diário, exames bioquímicos, avaliação histológica, exame morfométrico. RESULTADOS: Os animais mantiveram-se saudáveis durante o experimento, não tendo ocorrido extrusão do implante em nenhum animal. O exame morfológico mostrou que houve a formação de pseudocápsula ao redor dos cones, com superioridade dos cones de biovidro e biovitrocerâmico FI, os quais apresentaram menor reação inflamatória e menor formação da pseudocápsula ao redor dos cones que os demais. A reação inflamatória foi mais intensa após 7 dias da colocação dos cones, diminuindo em direção aos 180 dias, sendo menos intensa nos coelhos que receberam cones de biovidro. CONCLUSÃO: Os cones de biovidro e biovitrocerâmico FI e FII podem ser úteis para a reparação da cavidade anoftálmica, com melhor resposta quando se usa cones de biovidro e de biovitrocerâmico FI.

Estudo experimental do uso de rebolos convencionais na usinagem do aço VP-50 utilizado na retificação cilíndrica, por meio de diferentes métodos de lubri-refrigeração

Pós-graduação em Engenharia Mecânica - FEB

Características químico-mineralógicas e cerâmicas da matéria-prima utilizada pelo polo cerâmico de Rio Verde de Mato Grosso, MG

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Compósitos preparados a partir de resíduo industrial de couro com elastômeros termoplásticos obtidos através de blendas de polietileno de baixa densidade e borracha natural

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Uso do amido resistente na promoção da saúde intestinal de cães idosos: formação de produtos de fermentação e características histológicas da mucosa intestinal

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Fibra para cães: efeitos sobre o processo de extrusão, digestibilidade, fermentação microbiana, tempo de retenção intestinal e palatabilidade de rações para cães

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Multidisciplinary approach for crown-root fracture treatment after trauma: case report

The development of an accurate diagnosis and appropriate treatment plan can be a complex task, especially in cases of dentoalveolar trauma. The authors present a case report of crown-root fracture caused by trauma and highlight the importance of a multidisciplinary approach for the treatment. An eighteen year-old boy had a bicycle accident resulting in dental trauma. The upper right first molar showed a complicated crownroot fracture and the lower left second pre-molar showed an uncomplicated crown-root fracture. Endodontic treatment, controlled tooth extrusion, periodontal surgery for recovery of biological width, and porcelain crown and onlay restorations were performed. Esthetic and functional results were achieved. At the two-year follow-up it was observed that the tooth/onlay interface of the upper right first molar was stained and the onlay of the left lower second pre-molar was fractured. Therefore, the interface stained was repaired and a porcelain crown was made for the lower second premolar. The clinical case presented herein leads to the conclusion that a multidisciplinary treatment plan is extremely important for a proper resolution in cases of dentoalveolar trauma.

Caracterização dos compostos derivados de furoxano como inibidores da atividade de bombas de efluxo em Mycobacterium tuberculosis e estudo da influência do efluxo e da halotolerância nos perfis de resistência do bacilo

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)