Search

The effect of systematic and continuous environmental factors on milk performance traits over standard lactations in 2805 Simmental cows was evaluated using the general linear model. The systematic factors included the effect of farm or breeding area, calving season, year of birth, season of birth, lactation group and their interactions. The continuous factor analysed was the effect of age at first conception. The effect of farm, lactation group and calving season on standard lactation milk performance was found to be highly significant (P<0.01), excepting the effect of calving season on milk fat percent in standard lactations which showed statistical significance (P<0.05). The interactions between year and season of birth, farm and calving season, and farm and lactation group had a highly significant effect (P<0.01) on all performance traits studied. Age at first conception, as a continuous factor, had a highly significant effect (P<0.01) on milk yield and milk fat percent, and a non-significant effect on milk fat yield. The model used to correct the performance traits over standard lactations for the effect of systematic factors was highly significant (P<0.01). The variance of the model accounted for 20.06 and 37.31% of the total variance of milk fat yield and milk fat percent, respectively. The resulting coefficients of determination (R2) ranged from 0.20 for milk fat yield to 0.37 for milk fat percent. [ABSTRACT FROM AUTHOR]

High-quality polyaniline with conductivity reaching 5 S cm−1 has been prepared catalytically in acetonitrile using aniline, HCl, hydrogen peroxide, and 2 mol% of the copper catalyst methyl[tris(3-mesityl-1-pyrazolyl)borato]copper(ii) chloride ([MeB(3-(Mes)Pz)3]CuCl). The use of CuCl2·2H2O catalyst instead of [MeB(3-(Mes)Pz)3]CuCl and the solvent effects were also investigated. Polyaniline samples were characterized using CHN analysis, UV-visible spectroscopy, FT-IR spectroscopy, bulk conductivity measurements, cyclic voltammetry and electrochemical impedance spectroscopy. Results of these mutually independent techniques are consistent and indicate the formation of good quality emeraldine form of polyaniline from the [MeB(3-(Mes)Pz)3]CuCl catalyzed reaction in acetonitrile. The conductivity of the polymer prepared using [MeB(3-(Mes)Pz)3]CuCl catalyst depends strongly on the medium of preparation which follows the order acetonitrile > 1 : 1 acetonitrile–water mixture > water. The polymer prepared using CuCl2·2H2O instead of [MeB(3-(Mes)Pz)3]CuCl in a 1 : 1 acetonitrile–water mixture is of relatively poor quality and has a lower conductivity. HCl is also important for the formation of better quality polyaniline and higher yield. [ABSTRACT FROM AUTHOR]