The linke turbidity factor based on improved values of the integral Rayleigh optical thickness

Spectral data on extraterrestrial solar radiation, Rayleigh scattering, ozone absorption and absorption by the uniformly mixed gases are critically evaluated and used for computing the integral Rayleigh optical thickness of the clean and dry atmosphere for a given relative optical air mass or solar elevation angle. The results are compared to the corresponding values calculated with the help of the three parameterization formulae. Based on the comparison, the formula of Louche et al., slightly adjusted to the new values, may be recommended for general use. Equations are given for converting the earlier into the new values of the integral Rayleigh optical thickness and of the Linke turbidity factors based thereom. Both the earlier and the new algorithms yield identical values of the direct solar irradiance.     

High glycolytic potential does not predict low ultimate pH in pork

Extent of postmortem pH decline influences meat quality development. To better understand physiological determination of ultimate pH (pH_u), we utilized female and castrated male pigs from a line whose selection index includes differentiated pH_u. All genotypes of AMP-activated protein kinase γ3 subunit (AMPKγ3) V199I site were present. The mutant 199II genotype increased pH_u, but only in castrated males. Genotype affected glycolytic potential (GP), but GP was weakly associated with pH_u. A subset of animals was selected based on low (− Gly) and high (+ Gly) residual glycogen content, and compared with AMPKγ3 200Q, which is associated with low pH_u. Both + Gly and 200Q muscle contained glycolytic substrate at 24 h; however, 200Q muscle generated low pH_u and greater lactate compared to + Gly. Additionally,− Gly and + Gly groups exhibited similar pH_u despite a large difference in GP. In conclusion, high GP does not appear to directly impact the extent of postmortem pH decline.     

Einfluss einer gezielt aufgeprägten Mikrogeometriestreuung auf das Anregungsverhalten von Kegelradverzahnungen

In the design process of transmissions, one major criterion is the resulting noise emission of the powertrain due to the gear excitation. Within the past years, a lot of investigations have shown that the noise emission can be correlated to the quasi-static transmission error. Therefore, the transmission error can be used as a characteristic value for quality assurance by experimental inspections as well as for a tooth contact analysis in the design process.The noise behavior of gearboxes is mainly caused by the excitation in the tooth mesh. The standardized design and calculation methods for gears concentrate on the reduction of the excitation level. But often the physical sound characteristics do not fit in with the human noise perception. Thus gear design rules are required that are able to rate the excitation according to the perception.The effect of the targeted topography scatter generally described is the reduction of the gear mesh amplitudes with an increase of the background noise. The objective of the report is to develop an understanding of the influence of different micro geometry scatters on the excitation behavior.Finally, it is the aim to design an aurally-accurate micro geometry scattering for the optimization of ground bevel gears in terms of tonality reduction and increased background noise. By means of a variant calculation and weighted target variables, psychoacoustic optimized micro geometry scattering is designed. At the same time, attention is also focused on a simple production of mixed topographies.     

Partial discharge measurements in air and argon at low pressures with and without a dielectric barrier

Partial discharge (PD) characteristics in air and argon under low pressures down to 13.3 Pa (0,1 Torr) and 60 Hz AC energization are studied in an energized needle-plane electrode arrangement. The electrode configuration, vacuum chamber, facilities, and electrical connections for the experimental setup are described. Two cases are studied for each of two gases, air and argon, with 20 mm spacing between the two electrodes: (1) with and (2) without a Teflon/spl reg/ cap (dielectric barrier). Results for the four series of experiments and analysis of the discharge current pulse waveforms are presented. Topics discussed are the typical waveforms of the discharge current pulses at different pressures, and discharge current pulse rise time vs. pressure relationships.     

An expression for the calculation of grounding resistance in uniform soil

This paper introduces an expression to calculate the resistance of a ground grid in uniform soil. This expression is derived from the analysis of a series of numerical results given by a computer program based on the boundary element method. A comparison with results from other analytical techniques is given.     

Serologic survey of Toxoplasma gondii in grizzly bears (Ursus arctos) and black bears (Ursus americanus), from Alaska, 1988 to 1991

We tested 644 serum samples from 480 grizzly bears and 40 black bears from Alaska (USA), collected between 1988 and 1991, for Toxoplasma gondii antibodies, using a commercially available latex agglutination test (LAT). A titer > or = 64 was considered positive. Serum antibody prevalence for T. gondii in grizzly bears (Ursus arctos) was 18% (87 of 480). Prevalence ranged from 9% (seven of 77) on Kodiak Island to 28% (15 of 54) in northern Alaska. Prevalence was directly correlated to age. No grizzly bears < 2-year-old had T. gondii antibody. High antibody titers were found mainly in grizzly bears captured north of the Arctic Circle. Antibody prevalence in black bears (Ursus americanus) from Interior Alaska was 15% (six of 40), similar to the prevalence in grizzly bears from the same area (13%; five of 40).     

Lack of protection against avian cholera by vaccination with recombinant P6-like protein from Pasteurella multocida

The gene encoding the P6-like protein of Pasteurella multocida was cloned in the baculovirus expression system. Baculovirus-expressed recombinant protein was used to parenterally immunize 6-wk-old Nicholas broad-breasted white turkeys. Turkeys developed significant antibody titers to the recombinant protein as measured by enzyme-linked immunosorbent assay. Two weeks after the last immunizing injection, vaccinated turkeys were placed in contact with turkeys infected with P. multocida strain P1059, as were nonvaccinated control birds. No differences occurred in percent mortality between the two groups. We conclude that parenterally administered recombinant P6-like protein does not protect turkeys from avian cholera.