Thermal distortion analysis of a deployable parabolic reflector

A thermal distortion analysis of the ATS-6 Satellite parabolic reflector was performed using NASTRAN level 15.1. The same NASTRAN finite element method was used to conduct a one g static load analysis and a dynamic analysis of the reflector. In addition, a parametric study was made to determine which parameters had the greatest effect on the thermal distortions. The method used to model the construction of the reflector is described and the results of the analyses are presented

ATS-6 flight accelerometers

Five accelerometers mounted near the adapter base of the Titan 3-C launch vehicle and three on the hub of the ATS-F spacecraft provided (1) data for verifying basic spacecraft mode shapes and frequencies during powered flight while attached to the launch vehicle; (2) failure mode detection and diagnostic information on in-flight anomalies; and (3) data to be used in the design of future spacecraft to be flown on the Titan 3-C. Because data from the instruments mounted on the spacecraft hub passed through an in-flight disconnect at the separation plane between the transtage and ATS-F, the moment this connector was broken, the signal to the telemetry system showed a step function change. By monitoring these telemetry traces on the ground at appropriate times during flight sequences, a positive indication of spacecraft separation was obtained. Flight data showing dynamic response at spacecraft launch vehicle interface and at the top of ATS spacecraft during significant launch events are presented in tables

No Racial or Gender Disparities in Cardiac Rehabilitation Attendance after CABG

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Genetic maps of Saccharum officinarum L. and Saccharum robustum Brandes & Jew ex grassl.

Genetic analysis was performed in a population composed of 100 F1 individuals derived from a cross between a cultivated sugarcane (S. officinarum La Purple) and its proposed progenitor species (S. robustum "Mol 5829'). Various types (arbitrarily primed-PCR, RFLPs, and AFLPs) of single-dose DNA markers (SDMs) were used to construct genetic linkage maps to both species. The LA Purple map was composed of 341 SDMs, spanning 74 linkage groups and 1.881 cM, white the Mol 5829 map contained 301 SDMs, spanning 65 linkage gropus and 1,189 cM, Transmission genetics in these two species showed incomplete polysomy based on the detection of 15% of SDMs linked in repulsion in LA Purple and 13% of these in Mol 5829. Because of this incomplete polysomy, multiple-dose markers could not be mapped for lack of a genetic model for their segregation. Due to inclusion of RFLP anchor probes, conserved in related species, the resulting maps will serve as useful tools for breeding, ecology, evolution, and molecular biology studies within the Andropogoneae

Secular changes in the quiescence of WZ Sge: the development of a cavity in the inner disk

We find a dimming during optical quiescence of the cataclysmic variable WZ Sge by about half a magnitude between superoutbursts. We connect the dimming with the development of a cavity in the inner part of the accretion disk. We suggest that, when the cavity is big enough, accretion of material is governed by the magnetic field of the white dwarf and pulsations from the weakly magnetic white dwarf appear. The time scale of forming the cavity is about a decade, and it persists throughout the whole quiescent phase. Such a cavity can be accommodated well by the proposed magnetic propeller model for WZ Sge, where during quiescence mass is being expelled by the magnetic white dwarf from the inner regions of the accretion disk to larger radii.Comment: 10 pages, 4 figures, accepted for publication in Astronomy and Astrophysics; following referee report, many textual changes, figures improved, more historic data added, conclusions unchange

Surface Quality of a Work Material Influence on Vibrations in a Cutting Process

The problem of stability in the machining processes is an important task. It is strictly connected with the final quality of a product. In this paper we consider vibrations of a tool-workpiece system in a straight turning process induced by random disturbances and their effect on a product surface. Basing on experimentally obtained system parameters we have done the simulations using one degree of freedom model. The noise has been introduced to the model by the Langevin equation. We have also analyzed the product surface shape and its dependence on the level of noise.Comment: 12 pages, PDF of figures can be obtained from http://archimedes.pol.lublin.pl/~raf/graf/fpic.pd

Cyclic brightening in the short-period WZ Sge-type cataclysmic variable SDSS J080434.20+510349.2

We have observed a new cataclysmic variable (CV) SDSS J080434.20+510349.2 and study the origin of a long-term variability found in its light curve. Multi-longitude time-resolved photometric observations were carried out to analyze the uncommon behavior also found recently in two newly discovered CVs. This study of SDSS J080434.20+510349.2 mainly concerns the understanding of the nature of the observed double-humped light curve and its relation to a cyclic brightening occurring during quiescence. The observations were obtained early in 2007, when the object was at about V~17.1, 0.4 mag brighter than the pre-outburst magnitude. The light curve shows a sinusoidal variability with an amplitude of about 0.07 mag and a periodicity of 42.48 min, which is half of the orbital period of the system. In addition, we have observed two "mini-outbursts" of the system up to 0.6 mag, with a duration of about 4 days each. The "mini-outburst" had a symmetric profile and repeated in about 32 days. Subsequent monitoring of the system shows a cyclical behaviour of such "mini-outbursts" with a similar recurrence period. The origin of the double-humped light curve and the periodic brightening is discussed in the light of the evolutionary state of SDSS J080434.20+510349.2.Comment: 7 pages, 6 figures, Accepted by A&A, typos added, figure correcte

Restocking Northern Bobwhites in East Texas: A Genetic Assessment

Habitat on a 610-ha study area in the Pineywoods Ecological Region of eastern Texas was enhanced for northern bobwhites ( Coli nus virginianus). In February and March 1990, 1991, and 1992, bobwhites from south Texas (C. v. texanus) and disjunct areas of east Texas (C. v. mexicanus) were captured, radio tagged, and relocated to the study area which had a small ( \u3c25 birds) resident population. Blood samples were collected from the birds relocated in 1991. Samples were also collected from birds in the resident population during 1991 and 1992; these birds were assumed to be offspring of the previous years\u27 resident and relocated bobwhites. Restriction site variation of mitochondrial DNA (mtDNA) revealed geographic subdivision between the subspecies but not between resident and east Texas relocated birds. The observed frequency differences of mtDNA haplotypes were used to assess the relative reproductive success of the 2 subspecies. Among the birds examined for mtDNA variation, offspring produced on the study area during 1990 and 1991 were genetically more similar to the east Texas subspecies than to the south Texas subspecies. These results suggest that efforts to restock northern bobwhite should involve either local birds or birds from the same subspecies. Management implications of these findings are discussed

Quantum open systems and turbulence

We show that the problem of non conservation of energy found in the spontaneous localization model developed by Ghirardi, Rimini and Weber is very similar to the inconsistency between the stochastic models for turbulence and the Navier-Stokes equation. This sort of analogy may be useful in the development of both areas.Comment: to appear in Physical Review

Sequence Dependence of Self-Interacting Random Chains

We study the thermodynamic behavior of the random chain model proposed by Iori, Marinari and Parisi, and how this depends on the actual sequence of interactions along the chain. The properties of randomly chosen sequences are compared to those of designed ones, obtained through a simulated annealing procedure in sequence space. We show that the transition to the folded phase takes place at a smaller strength of the quenched disorder for designed sequences. As a result, folding can be relatively fast for these sequences.Comment: 14 pages, uuencoded compressed postscript fil