Effects of selenium and vitamin E on incidence of retained placenta

In a series of experiments over 3 yr, relatively low doses of selenium and vitamin E were injected intramuscularly 3 wk prepartum to pregnant Israeli-Holstein dairy cows in a high-producing herd (9000 kg milk/yr) with a history of retained placenta in 17% of the primiparous and 28% of the multiparous animals, as recorded for the 12 mo preceding the study. Selenium ranged from .035 to .109 ppm in the prepartum diet and from .160 to .200 ppm in the postpartum diet. Doses of selenium ranging from 2.3 to 23.0 mg reduced the incidence of retained placenta in 186 primiparous and in 428 multiparous to 7 and 15%, which was half of that of controls. Low doses of selenium (2.3 to 4.6 mg) tended to be more effective than higher ones. Selenium alone was at least as effective as a combination of selenium and vitamin E. Dosage, timing, mechanism, and interactions of selenium with other factors in reducing the incidence of retained placenta need clarification.     

Video tape manufacture by high vacuum evaporation—aspects of machine technology

The next generation of video tapes will use evaporated thin films with their superior properties such as recording density, output level, frequency characteristics and signal-to-noise ratio. This paper describes the metal layer formation by a simple model for the growth of microcolumns at oblique incidence deposition. The most relevant process parameters are discussed. The layout of a production coater is described.     

V. Yeast sequencing reports. Identification of a gene encoding a new Ypt/Rab-like monomeric G-protein in Saccharomyces cerevisiae

A Saccharomyces cerevisiae sequence cloned by serendipity was found to encode a protein that is a new member of the Ypt/Rab monomeric G-protein family. This sequence shows high homology to the yeast genes SEC4 and YPT1 and, like SEC4 and YPT1, is essential for viability. The sequence was localized to chromosome V based upon hybridization to pulse-field gel-separated yeast chromosomes. The sequence has been deposited in the GenBank data library under Accession Number L17070.     

Numerische Simulation der Faserbewegung beim Strangpressen kurzfaserverstärkter Glasschmelzen

Numerical Simulation of the Fibre-Motion during the Extrusion of Short-Fibre-Reinforced Glass-Melts Fibre-reinforced materials are characterized by an anisotropic behaviour of the mechanical properties, which is caused by the alignment of the embedded fibres. In the case of short-fibre-compounds this behaviour is strongly influenced by the mechanism of flow during the manufacturing process. Numerical simulation Methods are preferentially used to get informations about the orientation of the reinforced fibres at the end of the molding-process and to improve the properties of the compound. For that, a model is developed, which calculates the motion of the short-fibres in the area of flow, basing on a three-dimensional finite-element-computation. Thereby the interaction between the Particular fibres during the orientation process is considered by using an interaction coefficient. Examplified at the extrusion of short fibre reinforced glass-melts, the fibre orientation is determined at models with different geometries of the pressing tool and variable boundary conditions. This procedure allows to determine the influence of the process-parameters On the expected quality of the composite. The represented simulation-model can also be used for other molding- and extrusion-processes of fibre reinforced materials.     

Reliability of MDOF-systems

To estimate the safety and reliability of nonlinear structural (MDOF)-systems subjected to random dynamic loading the response surface methodology (RSM) and Monte Carlo Simulation (MCS) respectively appear to be the most general approaches to calculate the failure probabilities of such systems. In an effort to reduce the number of computational time consuming simulations as generally required for direct MCS, only a small part of which is important for the assessment of failure rates, a new selective MCS technique named ‘Double and Clump’ (D&C) is suggested. The main idea of this procedure is to increase for each time step the relatively low number of response samples containing higher mechanical energy. The selective MCS procedure is tested by analysing nonlinear SDOF oscillators, for which exact analytical solutions exist. A good agreement between the distributions F(x) in the tails is obtained covering a wide range, i.e. 10⁻⁷ < F(x) < 1·0–10⁻⁷. The efficiency of selective MCS is demonstrated by applying it to a six-storey frame structure subjected to earthquake excitation. A comparison with results obtained by using the RSM is presented and discussed.     

The Determination of the Level of Bicarbonate, Carbonate, or Carbon Dioxide in Aqueous Solutions

A rapid and convenient method for the measurement of bicarbonate, carbonate, or carbon dioxide in water was developed using fourier transform infrared spectroscopy (FTIR). Bicarbonate and carbonate are converted to carbon dioxide by lowering the pH of the solution, then the absorbance of the dissolved carbon dioxide at 2345 wavenumbers is measured using a liquid sample cell. If the measurement of dissolved carbon dioxide is the objective, the pH is not adjusted, and the carbon dioxide in the free form can be measured without interference from low levels of carbonates. The method is linear from 10.48 ppm to a minimum of 366.8 ppm carbon dioxide (r squared = 0.9996). The coefficient of variation at 10.48 ppm (LOD 3 signal/noise), 52.4 ppm, and 262 ppm is 45.6, 4.0, and 3.9, respectively. The average percent recovery at 10.48 ppm, 52.4 ppm, and 262 ppm is 74.5, 104.2, and 104.0, respectively.