This study evaluated the influence of diet and environmental conditions on intake behavior and activity of feedlot steers. Feedlot rations used were comprised of a main concentrate: (1) corn or (2) barley. A GrowSafe system measured individual animal intake and behavior and HOBO accelerometers measured steer standing time. An Onset weather station collected on site weather data. Steer daily intake displayed a diet by temperature class interaction (p ≤ 0.05). Relative temperature change had no effect on variation in intake (p = 0.60); however, diet influenced variation of intake (p < 0.01), where corn-fed steers had a greater coefficient of variation (CV) than barley-fed steers (21.89 ± 1.46 vs. 18.72 ± 1.46%). Time spent eating (min d−1) and eating rate (g min−1) both displayed a diet by temperature class interaction (p ≤ 0.05). Diet did not affect steer lying activity (p ≥ 0.12), however, time spent lying (min d−1) and frequency of lying bouts (bouts d−1) increased on relatively cold days while the duration of lying bouts (min bout−1; p < 0.01) decreased. Short-term environmental temperature changes interacted with diet influencing feedlot beef cattle intake behavior; however, they did not interact with basal diet in respect to steer activity.
Explosionproof (Ex) equipment is vital for use in explosive atmospheres. The knowledge of basic of area classification, zone, temperature class, types of protection and source of ignition is mandatory for testing, manufacturing, use, installation, inspection and maintenance of Ex equipment. The paper describes the area classification, types of protection and equipment protection level for hazardous areas.
Unresolved, spectrum or spectroscopic binaries containing F or G giant or supergiant primaries are being observed with the IUE satellite. In most cases the secondary is a B or early A star probably still on the main sequence. The temperature class of the secondary is determined accurately by UV spectral classification and/or analysis of the composite flux distribution. The flux analysis uses a large grid of intrinsic colors and yields a best trial-and-error fit for the spectral types of primary and secondary, their V magnitudes, and the interstellar reddening. From the temperature class of the secondary, its probable main-sequence luminosity leads to a luminosity estimate for the primary with an uncertainty of about one magnitude. Several single-lined spectroscopic binaries are also being observed at high dispersion (in collaboration with Ake, Fekel, Harvel, and Kondo), to get the differential velocity between components from which mass ratios can be determined and masses estimated for the supergiants.
AbstractThe classification of Of stars presents a number of problems, in part due to the small interval of the spectrum explored up to now. With J.M. Vreux an extended study has been made in the infrared region, up to 1.1μ. Be stars have been studied with L. Houziaux, The hydrogen Paschen lines and lines of helium I and II can be studied in the region and used to determine temperature class and luminosity.
In the lower main sequence, the coolest halo population stars do not appear to be particularly subluminous in either the standard HR diagram or the (MI, R-I) plane. Earlier type M subdwarf's (e.g., Kapteyn's Star) that lie one or more magnitudes below the main sequence exhibit enhanced hydride absorption bands relative to M dwarfs of the same temperature. From visual region (4500–7000 Å) low dispersion image tube spectrograms we find that the cool halo M dwarfs exhibit enhanced absorption in the CaOH 5530 Å band and Na I resonance lines. Easily noticeable changes in the strength of the CaH “B” band relative to that of the TiO bands was found to be more difficult to determine in halo dwarfs later than spectral type M4. Several M dwarfs with old disk type motions have spectral peculiarities similar to those of the halo dwarfs. In both cases, Balmer emission is not present in most stars, in the rest it is very weak. Therefore, the anomalous strength of the CaOH 5530 Å band and Na resonance lines appear to be a more conveniently utilized qualitative criterion in spectroscopically identifying very cool M dwarfs which are subluminous with respect to most main sequence stars of the same temperature class.
The Influence of Environmental Conditions on Intake Behavior and Activity by Feedlot Steers Fed Corn or Barley-Based Diets