911 resultados para Grain Refining
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Incluye Bibliografía
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Includes bibliography
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Our objective was to investigate the effects of rehydration with acid whey or water at three moisture levels, as well as the effects of bacterial inoculation, on the fermentation, chemical composition and aerobic stability of corn grain silages. The trial was conducted in a completely randomized design with four replicates in a factorial arrangement as follows: 3 (rehydration with three different moisture levels: 300,350 and 400 mL/kg of corn grain)x 2 (silage inoculated with bacteria or not inoculated (control))x 2 (liquid used in the rehydration: acid whey or water). Overall, corn grain silages rehydrated with acid whey produced more lactic acid than the silages rehydrated with water (13.8 vs. 12.6 g/kg of dry matter (DM), respectively). In addition, increases in the rehydration of corn grain silages promoted decreases (linear) in lactic acid concentration as well as in production of total acids. Although inoculated silages had higher pH as consequence of the rehydration using water at the three levels, these treatments presented high DM recovery. In general, neutral detergent fiber (aNDFom) decreased if inoculant was applied in corn grain silages rehydrated with acid whey. After silos opening, silages rehydrated with 350 or 400 mL/kg (independent of the liquid) had lower aerobic stability than silages rehydrated with 300 mL/kg. Overall, we found that the inoculant did not promote significant changes in the composition of the corn grain silage. In contrast, the potential of the use of acid whey in ensiling corn grain is high, as its addition leads to improvements in the fermentation process and aerobic stability of the silages. (C) 2014 Elsevier B.V. All rights reserved.
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For a lamb feedlot system became competitive it is essential that an equilibrate nutrition and functional feeding management happens naturally. Therefore, this experiment has the objective to evaluate the efficiency of whole corn grain diet on lambs performance and carcass quality parameters and ruminal papillae development. During the experiment twenty Dorper/Santa Inescrossbred lambs were used, divided randomly in two treatments: control diet and whole grain diet. The experimental design was completely randomized design and data analysis done by SISVAR using the Tukey test at 5% of probability. No statistical differences were observed on the characteristics evaluated for performance and carcass as well as the length and width of ruminal papillae. The composition of the diet together with the weight gain potential of the lambs can explain the good average daily weight gain of 0.284 kg. The initial body condition average was 2.1 (thin) and improved at the end of the trial period achieving3.15 (normal). Carcass yield reached 46.24%, the results is between the range ideal for specialty meat breeds ranging from 40 to 50%. The carcass conformation, fat cover conformation and the thickness of subcutaneous fat found can be classified as medians. Also there was no difference in the characteristics of ruminal papillae. Thus, it is concluded that the use of whole grain diet did not influence the characteristics evaluated; and the choice of diet should be made with regard to profitability, simplicity of use and availability of forage in feedlot. (C) 2014 Elsevier B.V. All rights reserved.
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The AA356 alloy is an alloy widely used in the automotive industry and aerospace due to its excellent mechanical properties. Refining the structure of eutectic silicon aluminum alloys is a fairly common practice in the foundry through treatment known as modification. This can be achieved by modifying agent adding chemicals such as contained in groups I and IIa of the periodic table and rare earths (europium, céreioi, praseodymium, neodymium, etc.). Has the ability to modify the structure of the eutectic, but only sodium and strontium produce an action modifier strong when used in low concentrations. The modifying effect of the shafts turn silicon into a fibrous form and branched surrounded by metallic matrix in the form of a composite structure that has the highest limit of tensile strength, ductility and machinability. In this work will be obtained ingots with and without the modifier type Al-10% Sr, made in sand molds and are generated and analyzed cooling curves and also the study of the macrostructure and microstructure of the solidified material. It was found that by adding the Al-Sr made shorten the solidification time and lower the grain size
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The study of mechanical properties of high-alloy special steels is of great interest of the steel industry due to the great demand by companies that manufacture automotive components of high criticality, and also because of its high commercial value. However, the development of this type of alloy metals demand highly technical knowledge. Among these extremely important kinds of steel, the subject which is the interest of this study is the special steel modified by niobium. The manganese and niobium are the main alloying elements in the composition of these steels, both of them increase the stability of the austenite region, however, manganese increases the hardenability and tensile yield strength, and niobium increases the mechanical strength and promotes refining the grain. The mechanical characterization of steel SAE 1312 modified the niobium was made in order to gain a better understanding of the influence on the mechanical properties caused by aging at different temperatures and for different reductions in the drawing of gauge material. This characterization was made by means of tensile test and hardness. This material showed an increase in yield strength and hardness when gauge with large reductions during the wiredrawing, but when subjected to aging temperatures higher than 300 ° C had a slight loss of these properties
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SnO2-based varistors are strong candidates to replace the ZnO-based varistors due to ordering fewer additives to improve its electrical behavior as well as by showing similar nonlinear characteristics of ZnO varistors. In this work, SnO2-nanoparticles based-varistors with addition of 1.0 %mol of ZnO and 0.05 %mol of Nb2O5 were synthesized by chemical route. SnO2.ZnO.Nb2O5-films with 5 μm of thickness were obtained by electrophoretic deposition (EPD) of the nanoparticles on Si/Pt substrate from alcoholic suspension of SnO2-based powder. The sintering step was carried out in a microwave oven at 1000 °C for 40 minutes. Then, Cr3+ ions were deposited on the films surface by EPD after the sintering step. Each sample was submitted to different thermal treatments to improve the varistor behavior by diffusion of ions in the samples. The films showed a nonlinear coefficient (α) greater than 9, breakdown voltage (VR) around 60 V, low leakage current (IF ≈ 10-6 A), height potential barrier above 0.5 eV and grain boundary resistivity upward of 107 Ω.cm.
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Pós-graduação em Engenharia Mecânica - FEG
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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The effects of the dietary substitution of dry corn by high-moisture corn grain silage (HMCGS) were evaluated on the performance, nutrient digestibility and serum biochemical parameters of broilers reared in an alternative production system and submitted to different environmental temperatures. A total of 288 one-day-old male Cobb chicks were distributed according to a randomized block design in a 3x4 factorial arrangement: three environmental temperatures (hot, thermoneutral or cold) and four levels of HMCGS in substitution of dry corn (0%, 20%, 40% or 60%). The acid analysis showed that the evaluated HMCGS contained average percentage values of ethanol, lactic acid, and acetic acid (expressed in 100% of dry matter) of 0.7690, 2.7320 and 0.0249%, respectively. Propionic and butyric acids were not detected. Dry corn and HMCGS presented pH values of 5.8 and 3.3, respectively. The inclusion of HMCGS reduced dietary pH, as shown by the values of 5.7, 5.4, 5.1 and 4.8 recorded for the diets containing 0%, 20%, 40% and 60% of HMCGS, respectively. There was no significant interaction between diets and environmental temperature. HMCGS may replace up to 40% dry corn in broiler diets when performance, triglyceride levels, and HDL-cholesterol ratio is considered, and up to 60% when nutrient digestibility is evaluated. High environmental temperature impairs broiler performance, nutrient digestibility, and serum biochemistry, demonstrating the influence of environmental temperature on broiler metabolism and performance.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Periodically, when necessary, standard documents are revised in order to analyze inconsistencies and to include considerations according new realities verified. In this sense, aiming to quantify the wood moisture content influence on modulus of elasticity, it was applied tension tests parallel to the grain for six specimens of different strength classes of wood, considering nominal moisture of 12, 20, 25, and 30% in Brazil. The present paper examine the adequacy of the current Brazilian standard ABNT NBR7190:1997, in review, about the adoption of a first degree equation to describe the influence of wood moisture content for timber structures design. It was obtained a new first degree equation which leads to statically equivalent estimations when compared with results by ABNT NBR7190:1997 equation. However, as recommendations it could be maintain the current expression for the next text of the referred document review, without prejudice to statistical significance of the estimates.