288 research outputs found

    Performance and health of dairy calves fed limited amounts of acidified milk replacer

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    To compare growth performance of Brown Swiss calves fed acidified milk replacer (AMR) at 8% of birth weight, 20 newborn calves were reared under a new calf-feeding programme. Body weights, total weight gains and gains in body measurements, feed intake and feed efficiency values determined at different stages of growth of AMR-fed calves were comparable to those of calves fed sweet milk replacer (SMR). Faecal consistency scores and percent days with diarrhoea of calves offered AMR from four to 35 days of age were respectively 0.4 and 19.1% lower than those fed SMR. Most of the behavioural parameters studied were not unfavourably influenced by acidification of the replacer. In conclusion, growth, feed intake and feed efficiency characteristics of Brown Swiss calves fed AMR or SMR were not different from each other. However, incidence of diarrhoea of the young calves was decreased and health status of the calves was improved with the feeding of acidified milk. South African Journal of Animal Science Vol. 36(3) 2006: 149-15

    Effects of shading and covering material application for delaying harvest on gray mold disease severity

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    To delay the harvest of Sultani Cekirdeksiz grape variety and to reduce pre and post-harvest botrytis bunch rot severity, shading and covering material application were tested in 2009 to 2010 growing periods. In this study, grape vines were shaded with shading materials which had three different shading densities (35, 55, and 75% shading density) from veraison period to harvest. The grape vines were also covered with four different covering materials (transparent polyethylene, mogul, polypropen cross-stich and lifepack) before rainfall, at the end of August until harvest. The gray mold severity was recorded three times (before shading at unriped grape stage, veraison period, shortly after shading and twice at 20 day interval) during growing period. Based on the results of this study, the highest gray mold (Botrytis cinerea) severity was obtained in the control (uncovered and unshaded) treatment and the lowest disease severity was observed in lifepack treatment with or without shading. Since gray mold disease of grape was the main factor affecting harvest date of the crop lifepack, + 35 or 55% shading could be recommended to delay harvest and reduce the gray mold severity of grape in Manisa province-Turkey.Key words: Sultani seedless, table grape, shading, cover material, delaying harvest disease severity, Botrytis cinerea

    Polaronic effects in a Gaussian quantum dot

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    The problem of an electron interacting with longitudinal-optical (LO) phonons is investigated in an N-dimensional quantum dot with symmetric Gaussian confinement in all directions using the Rayleigh-Schrödinger perturbation theory, a variant of the canonical transformation method of Lee-Low-Pines, and the sophisticated apparatus of the Feynman-Haken path-integral technique for the entire range of the coupling parameters and the results for N = 2 and N = 3 are obtained as special cases. It is shown that the polaronic effects are quite significant for small dots with deep confining potential well and the parabolic potential is only a poor approximation of the Gaussian confinement. The Feynman-Haken path-integral technique in general gives a good upper bound to the ground state energy for all values of the system parameters and therefore is used as a benchmark for comparison between different methods. It is shown that the perturbation theory yields for the ground state polaron self-energy a simple closed-form analytic expression containing only Gamma functions and in the weak-coupling regime it provides the lowest energy because of an efficient partitioning of the Gaussian potential and the subsequent use of a mean-field kind of treatment. The polarization potential, the polaron radius and the number of virtual phonons in the polaron cloud are obtained using the Lee-Low-Pines-Huybrechts method and their variations with respect to different parameters of the system are discussed. © 2007 Elsevier Ltd. All rights reserved

    Effects of slaughter age and muscle type on meat quality characteristics of Eastern Anatolian Red bulls

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    The effects of slaughter age and muscle type on meat quality properties of Eastern Anatolian Red (EAR) bulls (n=46) were investigated in the present study. Forty-six EAR bulls were slaughtered at 15, 17, 19, 25 and 27 months. Meat samples were taken from longissimus dorsi (LD) and gluteus medius (GM) muscles obtained from the carcasses at 24&thinsp;h post-mortem. Meat color parameters were significantly affected by slaughter age. Older animals (19, 25 and 27 months of age) possessed higher L*, a* and H values than those of younger animals (15 and 17 months of age). LD muscle had higher L* and a* values than those of GM muscles. The influences of slaughter age and muscle type on the proportions of dry matter, ether extract, crude ash and crude protein were not significant in the present study. The influence of slaughter age on the tenderness, acceptability, juiciness, number of chews and Warner–Bratzler shear (WBS) values were found to be significant. Tenderness, juiciness, flavor intensity and acceptability increased until 19 months of age, and then increase in age resulted in lower tenderness, flavor intensity and acceptability scores. Cooking yield significantly increased depending on the increase of age. WBS and cooking yield values from the LD were higher than that of the GM muscle. Textural characteristics such as hardness, springiness, cohesiveness, gumminess, chewiness and resilience were not affected by slaughter age, but muscles had a significant influence on hardness, gumminess, chewiness and resilience. In conclusion, most eating quality characteristics and color parameters were positively influenced by slaughter age.</p

    Multi-layered Ruthenium-modified Bond Coats for Thermal Barrier Coatings

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    Diffusional approaches for fabrication of multi-layered Ru-modified bond coats for thermal barrier coatings have been developed via low activity chemical vapor deposition and high activity pack aluminization. Both processes yield bond coats comprising two distinct B2 layers, based on NiAl and RuAl, however, the position of these layers relative to the bond coat surface is reversed when switching processes. The structural evolution of each coating at various stages of the fabrication process has been and subsequent cyclic oxidation is presented, and the relevant interdiffusion and phase equilibria issues in are discussed. Evaluation of the oxidation behavior of these Ru-modified bond coat structures reveals that each B2 interlayer arrangement leads to the formation of α-Al 2 O 3 TGO at 1100°C, but the durability of the TGO is somewhat different and in need of further improvement in both cases

    Fireside Corrosion in Oxy-Fuel Combustion of Coal

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    Oxy-fuel combustion is based on burning fossil fuels in a mixture of recirculated flue gas and oxygen, rather than in air. An optimized oxy-combustion power plant will have ultra-low emissions since the flue gas that results from oxy-fuel combustion consists almost entirely of CO2 and water vapor. Once the water vapor is condensed, it is relatively easy to sequester the CO2 so that it does not escape into the atmosphere. A variety of laboratory tests comparing air-firing to oxy-firing conditions, and tests examining specific simpler combinations of oxidants, were conducted at 650-700 C. Alloys studied included model Fe-Cr and Ni-Cr alloys, commercial ferritic steels, austenitic steels, and nickel base superalloys. The observed corrosion behavior shows accelerated corrosion even with sulfate additions that remain solid at the tested temperatures, encapsulation of ash components in outer iron oxide scales, and a differentiation between oxy-fuel combustion flue gas recirculation choices
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