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Itapetininga, Brazil

Rangel M.D.C.,Federal University of Bahia | Khodakov A.,Lille University of Science and Technology | Cadete Santos Aires F.J.,CNRS Research on Catalysis and Environment in Lyon | De Souza M.O.,Federal University of Rio Grande do Sul | And 4 more authors.
Studies in Surface Science and Catalysis | Year: 2010

The structure of cobalt nanoparticles on alumina and carbon nanotube supports, prepared by a simple and fast method, is investigated using a wide range of characterization techniques (TG, DTA, XRD, nitrogen adsorption, XPS, EXAFS and (HR)TEM). The samples were obtained by several cobalt impregnation steps and are expected to be efficient catalyts for Fischer-Tropsch synthesis. Cobalt nanoparticles ranging from 3 to 5 nm, forming small clusters of 10 to 20 nm, were successfully prepared on alumina and carbon nanotube, the morphology depending on the support. © 2010 Elsevier B.V. All rights reserved. Source


Argolo L.S.,Zootecnia UESB | Pereira M.L.A.,DEBI UESB | Dias J.C.T.,State University of Santa Cruz | da Cruz J.F.,DFZ UESB | And 2 more authors.
Revista Brasileira de Zootecnia | Year: 2010

The objective of this study was to evaluate the effect of adding mesquite pod meal (0, 33.3, 66.7 and 100%) to substitute corn meal on purin derivative the excretion, estimated by total urine collection, and on the ruminal parameters (pH, ammonia and volatile fatty acids). Eight lactating goats were used and distributed in a 4 × 4 Latin square and fed iso-protein diets consisting of 40% elephant grass silage and 60% concentrate. There was no significant effect from adding mesquite pod meal on the ruminal parameters. The pH ranged from 6.85 to 7.03 and the ruminal ammonia concentration averaged 6.97 mg/100 mL. The acetate and propionate concentrations ranged from 9.47 to 10.54 and 4.79 to 6.58 mM, respectively. The excretion (mmol/day) of allantoin, uric acid and xanthine-hypoxanthine, the quantity of absorbed purines, the nitrogen microbial intestinal flow (g/day), microbial nitrogen synthesis (g/day) and efficiency of microbial protein synthesis efficiency, expressed in g of microbial crude protein/kg of the total digestible nutrients, presented linear negative response to corn replacement with mesquite pod meal. Microbial synthesis in goats must be estimated by the purine derivatives excretion using equations obtained from goats. © 2010 Sociedade Brasileira de Zootecnia. Source


Santana H.A.,UESPI | Silva R.R.,DEBI UESB | Carvalho G.G.P.,Federal University of Bahia | Cardoso E.O.,DEBI UESB | And 7 more authors.
Archivos de Zootecnia | Year: 2013

The study was conducted to evaluate the effects of compensatory nutrition on supplemented pasture heifers on ingestive behavior. The experiment was conducted on the farm Princesa do Mateiro, Ribeirão do Largo, Bahia. Twenty 5/8 Guzera Dairy 3/8 Hostein heifers, with an average of 18 months of age and body weight of 187 ± 13.07 kg were used. The experiment lasted 224 days and the animals were maintained in pasture production, rotational grazing Brachiaria brizantha 'Marandu'. The animals were randomly assigned to each of the treatments: control (T100): Animals fed concentrate to supply 100% of the requirement of nutrients to gain 750 g/day; compensatory nutrition (CN): animals that alternated the feed level periodically being restricted fed concentrate to meet the requirement of 80% total digestible nutrients of the control treatment (T80) and refeeding fed concentrate to supply 120% of the total digestible nutrient requirements of the control treatment (T120). In periods of restriction, the average grazing time was greater for NC (533 vs. 426 minutes) (p<0.05). The grazing time and ruminating in feedback periods were lower than those of group NC (p<0.05). During refeeding, the number of periods spent at the trough and period of time for other activities were higher in animals of treatment NC (p<0.05). In the restricted period, there was no statistical differences between control and compensatory nutrition for the variables of bits and swallowing (p>0.05). During refeeding, the number of bits by swallowing, swallowing time and number of bites per day were lower (p<0.05) in animals of NC group when compared to control. The number of chews per day and the number of ruminating bolus per day were different between the control and NC (p<0.05). Compensatory nutrition alters the feeding behavior of crossbred heifers on pasture. Source


da Silva D.P.,DEBI UESB | Pruski F.F.,DEBI UESB | da Silva J.M.A.,Federal University of Vicosa | Filho W.D.M.M.,DEBI UESB
Revista Brasileira de Engenharia Agricola e Ambiental | Year: 2012

Unpaved roads are of great importance for the economic and social development of a country. Water erosion provoked by the concentration of runoff along the road is a principle cause of its degradation. The construction of infiltration basins for runoff retention on unpaved roads is a usually alternative for the problem solution. The use of more coherent methodologies for designing infiltration basins is fundamental for the appropriate road degradation processes control. Therefore, the objective of this work was to perform a comparative analysis of a methodology for the design of infiltration basins that consider an intense rainfall associated to a determined return period, with a methodology that use all events of a determined precipitation series, and overlapping effects of their respective runoff volumes. According to the obtained results, it was found that the volume calculated for the infiltration basin by the model which considers all events of the precipitation series is greater when the rate of water infiltration into the soil at the basin bottom is lowest. Source

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