High Pressure Hydraulic Supply System Model

A mathematical model is derived to provide quasi-steady state predictions of the performance of a high pressure hydraulic supply system, using equations which govern the physical processes as opposed to equations which match input-output characteristics. Model equations are developed to describe the operation of the power source, control valves, energy source, gas side of the system, hydraulic accumulator, the motorpump, and hydraulic side of the system. The accuracy of the model is then checked by inserting known parameters from a previously developed control system and comparing model predictions with performance data from this system

Positron annihilation spectroscopy with magnetically analyzed beams

Lifetime measurements with magnetically analyzed positron beams were made in condensed media with uniform and non-uniform properties. As expected, the lifetime values with magnetically analyzed positron beams in uniform targets are similar to those obtained with conventional positron sources. The lifetime values with magnetically analyzed beams in targets which have non-uniform properties vary with positron energy and are different from the conventional positron source derived lifetime values in these targets

Positron lifetime studies in thermoplastic polyimide test specimens

Positron lifetime measurements were made in two thermoplastic polyimide materials recently developed at Langley. The long component lifetime values in polyimidesulfone samples are 847 + or - 81 Ps (dry) and 764 + or - 91 Ps (saturated). The corresponding values in LARC thermoplastic imides are 1080 + or - 139 Ps (dry) and 711 + or - 96 Ps (saturated). Clearly, the presence of moisture has greater effect on positron lifetime in LARC thermoplastic imides than in the case of polyimidesulfones. This result is consistent with the photomicrographic observations made on frozen water saturated specimens of these materials

Improved Apparatus for the Measurement of Fluctuations of Air Speed in Turbulent Flow

This report describes recent improvements in the design of the equipment associated with the hot-wire anemometer for the measurement of fluctuating air speeds in turbulent air flow, and presents the results of some experimental investigations dealing with the response of the hot wire to speed fluctuations of various frequencies. Attempts at measuring the frequency of the fluctuations encountered in the Bureau of Standards' 54-inch wind tunnel are also reported. In addition, the difficulties encountered in the use of such apparatus and the precautions found helpful in avoiding them are discussed

Bobcat Predation on Quail, Birds, and Mesomammals

We reviewed 54 scientific articles about bobcat (Lynx rufus) food habits to determine the occurrence of quail, birds, and mesopredators including red (Vulpes vulpes) and gray fox (Urocyon cinereoargenteus), raccoon (Procyon lotor), skunk (Mephitis spp.), and opossum (Didelphis virginianus). Quail (Colinus virginianus, Cyrtonyx montezumae, Callipepla squamata, C. gambelii, C. californica, Oreortyx pictus) were found in 9 diet studies and constituted 3% of the bobcat diet in only 2 of 54 studies. Birds occurred in 47 studies, but were also a minor dietary component in most studies. Although mesopredators were represented as bobcat prey in 33 of 47 studies, their percent occurrence within bobcat diets was low and showed regional patterns of occurrence. Bobcats are a minor quail predator, but felid effects on mesopredators and secondary impacts on quail need to be studied

Variability of alkaloid content in Papaver somniferum L.

A total of 300 accessions of opium poppy (Papaver somniferum L., Papaveraceae) of the IPK genebank collection from nearly all over the world were cultivated under field conditions in Gatersleben for morphological and phytochemical characterisation. Altogether 35 morphological and agronomic characters were collected for all accessions. Determination of chromosome numbers with flow cytometry showed that the accessions of subspecies setigerum are tetraploid whereas all accessions of the other subspecies are diploid. Composition and content of the five main alkaloids (morphine, codeine, thebaine, papaverine and noscapine) were analysed by high performance liquid chromatography (HPLC). Total alkaloid content varied between 683.32 and 25,034.84 μg/g dry matter (first year) and 1,799.49 and 25,338.55 μg/g dry matter in the second year of cultivation. There is a highly significant correlation between total content of alkaloids and morphine in both years (r=0.926/P=0.000; r=0.918/P=0.000). In contrast, the other four main alkaloids show less or no correlation with each other or the total alkaloid content. This analysis demonstrated that the amount and composition of the main alkaloids are highly variable. Additionally, there is no important correlation between morphological characters and alkaloid content. So it is not possible to use these characters as a prediction tool of alkaloid content during breeding process