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81.
Horan John J.; Baker Stanley B.; Hoffmann Alan M.; Shute Robert E. 《Canadian Metallurgical Quarterly》1975,43(1):68
Assigned 40 overweight female Ss to 1 of 8 treatment combinations in a 2 * 2 * 2 matrix. The use of positive coverants produced significantly (p 相似文献
82.
Development of an implantable automatic defibrillator is dependent on achieving a reduction in the energy required for defibrillation, which is related to an optimal electrode configuration. This study investigated the use of a transvenous catheter electrode utilizing the damped sinusoidal waveform; compared the defibrillation effectiveness of varying the configuration of the four electrode units and of using a catheter/subcutaneous metal plate combination; and determined the lowest energy level necessary for near consistent transvenous defibrillation. 相似文献
83.
The effect of longitudinal mixing on nitrification was evaluated in two bench scale activated sludge reactors of equal volume, one approximating complete mixing (∂ = 0.62) and one approximating plug-flow mixing (∂ = 0.07). The onset of nitrification was more rapid under plug-flow conditions and a higher rate constant for nitrification was observed. Both the numbers and species of nitrifying bacteria were the same in both reactors and thus this did not contribute to the observed differences. Lower reaction rates in the complete mix reactor were shown to result from a high concentration of free ammonia in the mixed liquor, which gave rise to inhibition of nitrifying bacteria. Over an extended operating period, the plug flow reactor produced a sludge which demonstrated superior settling properties to that of the complete mix reactor. In addition incidences of sludge bulking were absent, whereas they were a regular feature of the complete mix system. 相似文献
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The primary objective of the study was to quantify the effect of genetic improvement using the Irish total merit index (Economic Breeding Index) on dry matter intake and feed efficiency across lactation and to quantify the variation in performance among alternative definitions of feed efficiency. Three genotypes of Holstein-Friesian dairy cattle were established from within the Moorepark dairy research herd: 1) low Economic Breeding Index North American Holstein-Friesian representative of the Irish national average dairy cow, 2) high genetic merit North American Holstein-Friesian, and 3) high genetic merit New Zealand Holstein-Friesian. Animals from within each genotype were randomly allocated to 1 of 2 possible intensive pasture-based feed systems: 1) the Moorepark pasture system (2.64 cows/ha and 500 kg of concentrate supplement per cow per lactation) and 2) a high output per hectare pasture system (2.85 cows/ha and 1,200 kg of concentrate supplement per cow per lactation). A total of 128 and 140 spring-calving dairy cows were used during the years 2007 and 2008, respectively. Each group had an individual farmlet of 17 paddocks, and all groups were managed similarly throughout the study. The effects of genotype, feed system, and the interaction between genotype and feed system on dry matter intake, milk production, body weight, body condition score, and different definitions of feed efficiency were studied using mixed models with factorial arrangements of genotypes and feed systems accounting for the repeated cow records across years. No significant genotype-by-feed-system interactions were observed for any of the variables measured. Results showed that aggressive selection using the Irish Economic Breeding Index had no effect on dry matter intake across lactation when managed on intensive pasture-based systems of milk production, although the ranking of genotypes for feed efficiency differed depending on the definition of feed efficiency used. Performance of animals grouped on alternative definitions of feed efficiency showed that conventional definitions such as feed conversion efficiency or residual feed intake may be inappropriate measures of efficiency for lactating dairy cows. An alternative definition, residual solids production, is proposed. This definition of feed efficiency identifies animals that produce greater volumes of milk solids at similar levels of feed intake without excessive body tissue mobilization and with improved fertility performance. The results also suggest that although there are differences in feed efficiency between strains of Holstein-Friesian, there is also variation within genotypes so that improvements in feed efficiency can be realized if the appropriate definition of feed efficiency is incorporated into breeding programs. 相似文献
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The authors report on arrays of normally on asymmetric Fabry-Perot modulator (AFPM) devices which exhibit a high degree of uniformity between devices, with a thickness variation across an array of 0.07%. The devices in one array have a mean insertion loss of 1.8 dB and have off reflectivities of less than 3%, giving a mean contrast ratio of 22:1. These characteristics are measured at a single operating wavelength of 857 nm. The spatial light modulators show promise for the use of AFPM devices in optical processing 相似文献
89.
The first part of this article, which appeared in the June issue, described the nature of infrared scanners and the results of some satellite IR experiments. In this concluding installment, the parametric relationships between the scanner and the spacecraft are set forth. The suborbital velocity/altitude ratio is fixed for a satellite in a circular orbit. Thus, such parameters as coverage, resolution, and scan rate can be expressed in terms of altitude. Since the signal-to-noise ratio of the sensor output is also a function of many of these same parameters, an evaluation of the IR system performance can be made. Equations are developed for relating the sensor, the mission, and the spacecraft in terms of an overall IR system. 相似文献
90.
Cynthia Horan 《Journal of Urban Affairs》2002,24(1):19-33
This article considers in what ways Clarence Stone’s urban regime paradigm is a useful framework for analyzing African American politics in cities. The article begins with a critical appraisal by Jeffrey Edwards that largely dismisses Stone’s study of Atlanta. It then offers a different interpretation of Stone’s scholarship, showing where Edwards shortchanges Stone’s framework and where his criticisms seem appropriate. The article then discusses how Adolph Reed Jr.’s black urban regime paradigm enhances Stone’s regime politics approach. 相似文献