EFFECT OF PARTIAL METAL REDUCTION ON THE CATALYTIC PROPERTY OF FE/SIO2 IN CO HYDROGENATION

Effect of partial metal reduction on the property of supported iron catalysts has been studied using 9.1 wt% Fe/SiO2 as a model catalyst and CO hydrogenation as a test reaction. The extent of iron reduction does not alter the intrinsic activity of iron nor distribution of the hydrocarbon products with specific carbon numbers, but significantly changes the olefin/paraffin ratio among the products. This kinetic behavior agrees with the result of gas chemisorption that the H2/CO adsorption ratio decreases as the catalyst is reduced poorly. Well-reduced iron catalysts deactivate during the reaction because the carbon species deposited on the surface gradually transform into less-reactive ones as observed in the TPSR experimentsclose1

Substituição parcial de silagem de milho por farelo de glúten de milho desidratado na alimentação de vacas holandesas em lactação Partial replacement of corn silage by corn gluten feed in the feeding of dairy Holstein cows in lactation

Objetivou-se estudar o efeito da substituição de parte da silagem de milho por farelo de glúten de milho (FGM-21) desidratado na produção e composição do leite e nos parâmetros sangüíneos de vacas em lactação e avaliar economicamente essa substituição. Foram avaliados os níveis 0, 8 e 16% de inclusão de FGM-21 (% MS) nas dietas. Trinta vacas foram utilizadas no estudo da produção e composição do leite e 15 vacas no estudo dos parâmetros sangüíneos. O delineamento experimental foi quadrado latino 3 <FONT FACE=Symbol>&acute;</FONT> 3 com dez replicações. Houve diferença entre as dietas para a produção de leite e a produção de leite corrigida para 3,5% de gordura. As demais características estudadas não diferiram entre as dietas. Para produção de leite, foram obtidos os valores de 22,44; 23,69 e 23,88 kg/vaca/dia; para produção de leite corrigida para 3,5% de gordura, 23,25; 24,71 e 24,44 kg/vaca/dia; para porcentagem de gordura, 3,69; 3,76 e 3,65%; para proteína no leite, 3,22; 3,20 e 3,25%; lactose, 4,29; 4,32 e 4,31%; sólidos totais, 12,12; 12,23 e 12,14%; N-uréico no leite, 16,57; 16,50 e 14,96 mg/dL; N-uréico plasmático, 19,92; 21,17 e 20,21 mg/dL; e para glicose sérica, 55,69; 56,50 e 54,78 mg/dL nos níveis 0, 8 e 16% de FGM-21, respectivamente. A dieta com 16% de FGM-21 resultou em maior lucro.<br>The objective was to study the effects of partial replacing of corn silage by corn gluten feed (CGF-21) dehydrated on milk production and composition of milk and in the blood parameters of dairy cows, beyond the economic evaluation. Inclusion levels of 0, 8 and 16% of CGF-21 (% DM) to the diets were evaluated. Thirty cows were used for study of milk production and composition and fifteen cows for blood parameters study. A 3 x 3 Latin Square experimental design with ten replications was used. There was difference among diets for milk yield and for 3.5% fat correct milk. No difference among diets was observed for the other studied characteristics. The results obtained for milk yield were: 22.44, 23.69 and 23.88 kg/anim.d and for 3.5% fat correct milk were: 23.25, 24.71 and 24.44 kg/anim.d, respectively, for the inclusionj levels of CGF-21 for the inclusion levels of 0, 8 and 16% of CGF-21 in the diet. The results obtained for the composition of milk were: percentage of fat, 3.69, 3.76 and 3.65%; milk protein, 3.22; 3.20 and 3.25%; lactose, 4.29, 4.32 and 4.31%; total solids, 12.12, 12.23 and 12.14%; N-ureic milk, 16.57, 16.50 and 14.96mg/dL, and for blood parameters were: plasma N ureic, 109.92, 21.17 and 20.21 mg/dL, seric glucose, 55.69, 56.50 and 54.78 mg/dL, respectively, for the inclusion levels of 0, 8 and 16% of CGF-21 in the diet. The diet with the inclusion of 16% of CGF-21 result on a greater profit