Response in blood and urinary parameters of dairy cows to the increase in dietary cation-anion balance

Estudou-se efeito de quatro níveis de dietas catiônicas sobre os parâmetros ácido-base do sangue e o pH urinário de vacas em lactação. Para a manipulação dos níveis do balanço cátion-amônico da dieta (BCAD), foram adicionadas diferentes concentrações de bicarbonato de sódio às dietas, obtendo-se os seguintes tratamentos: +150, +250, +400 e +500mEq/kg de matéria seca. O experimento foi realizado durante o verão, por um período total de 72 dias, utilizando-se oito vacas da raça Holandesa após o pico de lactação, distribuídas em quadrado latino (4x4), replicado, em que cada período teve duração de 18 dias. O pH urinário e o bicarbonato, o pH, o CO2 total e a pCO2 do sangue aumentaram linearmente (P<0,01) com o aumento do BCAD. As concentrações de sódio e potássio do sangue não foram modificadas (P>0,05) pelo BCAD. A concentração de cloro no sangue diminuiu linearmente (P<0,01) com o aumento do BCAD. O aumento do BCAD afetou o equilíbrio ácido-base das vacas, promovendo efeito alcalinogênico, o que poderia levar a diferenças significativas no desempenho do animal.The effect of four levels of cationic diets on acid-basic parameters of blood and the urinary pH were studied in dairy cattle. In order tomanage the dietary cation-anion balance (DCAB) different concentrations of sodium bicarbonate were added to diets, obtaining the following treatments: +150, +250, +400, and +500mEq/kg dry matter. The experiment was performed during the summer, totalizing 72 days, using eight Holstein cows after the lactating peak, distributed in 4 x 4 replicated latin square, with 18 days in each period. The urinary pH and the blood parameters (bicarbonate, pH, total CO2, and pCO2) linearly increased (P<0.01) with the DCAB increase. The sodium and potassium concentrations in blood were not modified (P>0.05) by DCAB. The chloride concentration in blood linearly decreased (P<0.01) with the DCAB increase. The DCAB increase affected the acid-base status of cows, promoting an alkalinogenic effect, what could lead to significant differences on animal performance

Clinicopathological and toxicological aspects of poisoning by the clomazone herbicide in sheep

AbstractClomazone (2-[(2-chlorophenyl)methyl]-4,4-dimethyl-3-isoxazolidinone) is a herbicide which has been widely used in southern Brazil in the rice cultivation and can be toxic for humans and animals. This study reports the first outbreak poisoning due to clomazone in a flock of 103 sheep, 20 of which showed mainly neurological and respiratory signs. Clomazone was detected in soil and vegetation samples and in the liver, kidney and muscles of poisoned animals. The poisoning was experimentally reproduced in three sheep by the administration of a 134mgkg body weight dose of clomazone. In both the natural and experimental cases, the clinical signs included tachypnea, anorexia, somnolence, weakness and ataxia. Macroscopically, there were no significant changes. Histologically, vacuolization in the white matter, perineuronal vacuoles and congestion of the leptomeningeal and brain vessels were observed. Ultrastructurally, the vacuolar lesions in the brain corresponded to swelling of the dendrites and astrocytic processes. It is concluded that clomazone causes toxic neuropathy in sheep

The Cyclonic Dryer - A Numerical And Experimental Analysis Of The Influence Of Geometry On Average Particle Residence Time

Particle residence time is an extremely important variable in a cyclonic dryer project. With the goal of obtaining a device that conduces to a long particle residence time, the influence of cyclone dimensions on particle residence time and on the type of flow is discussed here. The research was based on a device with a very high ratio of cyclone diameter to other dimensions. Simulations were developed with computational fluid dynamics techniques by the use of the commercial code CFX 4.4® of AEA Technology. Particles were treated individually. The fit of a turbulence model was also discussed. Theoretical and experimental results showed that the dimensions of the conical part of the cyclone had a very important influence on flow and consequently on particle residence time. The influence of volumetric concentration and particle diameter on particle residence time were also observed.211103112Abujelala, M.T., Lilley, D.G., Limitations and empirical extensions of the k-ε model as applied to turbulent confined swirling flows (1984) Chemical Eng. Communications, 31, pp. 223-236(2000) CFX-4.4 User Guide: Solver, , AEA Technology, United KingdomCorrêa, J.L.G., Rios, M.T.T., Silva, M.A., Nebra, S.A., Study of particle residence time in cyclones (2000) Proceedings of the 28th ENEMP, Teresópolis, RJ, pp. 165-172. , (in Portuguese)Corrêa, J.L.G., Chamma, M.O., Godoy, A.L., Silva, M.A., Nebra, S.A., Experimental study of drying and residence time of sugar cane bagasse in cyclonic devices (2001) Proceedings of 2nd Inter-American Drying Conference, Boca del Rio, Veracruz, Mexico, pp. 407-414. , ISBN 968-5401-01-2Corrêa, J.L.G., Graminho, D.R., Silva, M.A., Nebra, S.A., Simulation and experimental study of gas flow in a cyclonic chamber (2001) Proceedings of the 29th ENEMP, São João del Rei, MG, on CD-ROM, , (in Portuguese)Corrêa, J.L.G., Graminho, D.R., Silva, M.A., Nebra, S.A., Cyclone as a sugar cane bagasse dryer (2002) Proceedings of the 13th International Drying Symposium (IDS 2002), Beijing, China, C, pp. 1542-1549Corrêa, J.L.G., Silva, M.A., Nebra, S.A., Experimental and theoretical study of particle residence time in a cyclonic chamber (2002) Proceedings of the 13th International Symposium on Transport Phenomena, Elsevier, Victoria, BC, Canada, pp. 63-67. , ISBN 2-84299-391-8Corrêa, J.L.G., Peres, A.P., Graminho, D.R., Pacifico, A.L., Godoy, A.L., Silva, M.A., Nebra, S.A., Anaysis of flow in a venturi particle feeder (2002) Proceedings of the 14th Brazilian Congress of Chemical Engeneering, , (in Portuguese)Corrêa, J.L.G., Graminho, D.R., Silva, M.A., Nebra, S.A., Experimental study of sugar cane bagasse in cyclone (2003) 2nd Nordic Drying Conference, Copenhagen, DenmarkCorrêa, J.L.G., Graminho, D.R., Silva, M.A., Nebra, S.A., Cyclone as a sugar cane bagasse dryer (2003) Chinese Journal of Chemical EngineeringCorrêa, J.L.G., Discussion of cyclonic dryer project parameters (2003), Ph.D.diss., State University of Campinas, Campinas - SP(in Portuguese)Dibb, A., Silva, M.A., Cyclone as a drier - The optimum geometry (1997) Proceedings of the First Inter-American Drying Conference (IADC), Itu, SP, Brazil, B, pp. 396-403Dirgo, J., Leith, D., Performance of theoretically optimized cyclones (1985) Filtration and Separation, 22, pp. 119-125Griffiths, W.D., Boysan, F., Computational fluid dynamics (CFD) and empirical modeling of the performance of a number of cyclone samplers (1996) Journal of Aerosol Science, 27 (2), pp. 281-304Heinze, C., A new cyclone dryer for solid particles (1984) Ger Chem. Eng., 7 (4), pp. 274-279Hoekstra, A.J., Derksen, J.J., Van Den Akker, H.E.A., An experimental and numerical study of turbulent swirling flow in gas cyclones (1999) Chemical Engineering Science, 54, pp. 2055-2065Iozia, D.L., Leith, D., Effect of cyclone dimensions on gas flow pattern and collection efficiency (1989) Aerosol Science and Technology, 10, pp. 491-500Ismail, K.A., Gonçalves, M.M., Benevenuto, F.J., Instrumentação básica para engenharia (1998), Editora da Unicamp, Campinas, SP. ISBN 85-900609-1-8Jackson, R., Mechanical equipment for removing grit and dust from gases (1963), Great Britain: The British Coal Utilization Research AssociationLaunder, B.E., Reece, G.J., Rodi, W., Progress in the development of a Reynolds stress turbulence closure (1975) Journal of Fluid Mechanics, 68, pp. 537-566Lede, J., The cyclone: A multifunctional reactor for the fast pyrolysis of biomass (2000) Ins. & Eng. Chem. Research, 39, pp. 893-903Lede, J., Soulignac, H.L., Li, F., Villermaux, J., Measurement of solid particle residence time in a cyclone reactor: A comparison of four methods (1987) Chem. Eng. Proc., 22, pp. 215-222Ter Linden, A.J., Investigations into cyclone dust collector (1949) Proc. Inst. Mech. Eng. J., 160, pp. 233-251Ludera, L.M., Design methods for cyclone preheaters of rotary kilns (1989) Zement-Kalk-Gips, 1, pp. 10-12Meier, H.F., Peres, A.P., Fugihara, T.J., Martignoni, W.P., Mori, M., Comparison between turbulence models for 3-D turbulent flows in cyclones (2000) Proceedings of the XXI Cilance - Iberian Latin American Congress on Computational Methods in Engineering, Rio de Janeiro, on CD-ROMMohammadi, B., Pironneau, O., Analysis of the k-epsilon turbulence model (1994) Research in Applied Mathematics, , John Wiley and Sons, ParisMori, T., Suganuma, A., Tanaka, S., On collection efficiency of gas cyclone in coarse particle range (1968) Journal of Chemical Engineering of Japan, 1, pp. 82-86Nebra, S.A., Silva, M.A., Mujumdar, A.S., Drying in cyclones - a review (2000) Drying Technology, 18, pp. 791-832Ogawa, A., Mechanical separation process and flow patterns of cyclone dust collectors (1997) American Society of Mechanical Engineers, 50, p. 97Patankar, S.V., (1980) Numerical Heat Transfer and Fluid Flow, , Washington: Hemisphere Publishing CoXiang, S.H.R., Park, S.H., Lee, K.W., Effects of cone dimension on cyclone performance (2001) Aerosol Science, 32, pp. 549-561Santana, J.D.A.M., Arnosti Jr., S., Coury, J.R., Performance of cylindrical-conical cyclones with different geometrical configurations (2001) Brazilian Journal of Chemical Engineering, 18 (3), pp. 233-241Silva, M.A., Study of drying in cyclones (1991), Ph.D. diss., State University of Campinas, Campinas, SP(in Portuguese)Yuu, S., Jotaki, T., Tomita, Y., Yoshida, K., The reduction of pressure drop due to dust loading in a conventional cyclone (1978) Chemical Engineering Science, 33, pp. 1573-158

Resposta da figueira (Ficus carica L.) ao uso da irrigação e nitrogênio na região de Ilha Solteira

The study had the purpose of evaluating the effects of irrigation and nitrogen fertilization levels upon fig-tree orchards (harvest 1991/1992). A randomized split-plot block design was installed with six irrigation levels (0, 25, 50, 75,100 and 125% of Class A Pan Evaporation) and six nitrogen levels (0, 150, 300, 450, 600 and 750 g/plant), with four repetitions. According to the statistical analysis, significant effects of water supply were verified on ripe fruit harvest, total productivity, branch lenght and ripe fruit heigth and diameter. Nitrogen fertilization effects on ripe fruit harvest and branch lenght were also detected.Com o objetivo de avaliar a resposta da cultura da figueira (safra 91/92) à aplicação de lâminas de irrigação e adubação nitrogenada realizou-se um experimento com seis lâminas de irrigação (O, 25, 50, 75,100 e 125% da evaporação do Tanque Classe A) e seis níveis de nitrogênio (0,150,300,450,600 e 750 g/planta), instalado de acordo com um delineamento de blocos casualizados, em um esquema de parcelas sub-divididas, com quatro repetições. Com base na análise estatística realizada, verificou-se efeito significativo da irrigação sobre a produtividade de frutos maduros, produtividade total, comprimento de ramos e altura e diâmetro de frutos maduros. A adubação nitrogenada mostrou efeito significativo sobre a produtividade de frutos maduros e comprimento de ramos

XPS characterization of Au (core)/SiO2 (shell) nanoparticles

Core-shell nanoparticles with ca. 15-nm gold core and 6-nm silica shell were prepared and characterized by XPS. The Au/Si atomic ratio determined by XPS is independent of the electron takeoff angle because of the concentric spherical shape of the nanoparticles. The formula given by Wertheim and DiCenzo (Phys. Rev. B 1988, 37, 844) for spherical nanoparticles and the modified one by Yang et al. (J. Appl. Phys. 2005, 97, 024303) for core-shell nanoparticles are used to correlate the XPS-derived composition with the geometry of the nanoparticles only after significantly modifying either the bulk density of the silica shell or the attenuation length of the photoelectrons. © 2005 American Chemical Society

Estudio del valor nutritivo de la melaza para cerdos.

Se presentan los resultados de 3 experimentos de alimentación de cerdos con melaza, realizados con un total de 462 animales en las Granjas Experimentales de Tibaitatá y Palmira. En el experimento 1, realizado en Tibaitatá con su replicación en Palmira, se estudia el efecto de 13, 16 y 19 por ciento de proteína de niveles de 0, 25.5 y 30 por ciento de melaza, sobre el comportamiento de cerdos en crecimiento y acabado. Los resultados indican que cuando la dieta incluye melaza, puede usarse torta de soya como suplemento proteíco para dar un nivel de 13 a 16 por ciento de proteína. La melaza se puede incluír a niveles de 22.5 a 30 por ciento sin afectar los aumentos de peso, reduciendose el costo de producción aunque se aumente la cantidad de alimento. En el experimento 2 se suministra K en la forma de acetato y carbonato en la cantidad que lo contiene un nivel de 30 por ciento de melaza. Ninguna de las formas de suministro del K produjo transtornos gastrointestinales ni afectó los aumentos de peso o la eficiencia alimenticia. En el experimento 3 se estudia cuál de 4 niveles de melaza: 0, 15, 22.5 y 30 por ciento es el más adecuado para incorporar en la dieta para cerdos en crecimiento y acabado. Los niveles de 22.5 y 30 por ciento produjeron los aumentos de peso más económicos. Además al estudiar la doble suplementación de vitaminas del Complejo B se concluye que no mejora la tasa de aumento ni de utilización del alimentoPorcicultur