82,279 research outputs found
Fatigue failure load indicator
An indicator for recording the load at which a fatigue specimen breaks during the last cycle of a fatigue test is described. A load cell is attached to the specimen which is alternately subjected to tension and compression loads. The output of the load cell which is proportional to the load on the specimen is applied to the input of a peak detector. Each time the specimen is subjected to a compression load, means are provided for applying a positive voltage to the rest of the peak detector to reset it. During the last cycle of the tension load the peak detector measures the maximum load on the specimen. Means are provided for disconnecting the load cell from the peak detector when there is a failure in the specimen
Determination of impact sensitivity of materials at high pressures
Compact device is used to determine impact sensitivity of material in static, high pressure, gaseous environment. It can also be instrumented to monitor and record pressure, temperature, and striker impact force. Device is used in conjunction with commercially available liquid oxygen impact tester which provides impact energy
A rocket-borne data-manipulation experiment using a microprocessor
The development of a data-manipulation experiment using a Z-80 microprocessor is described. The instrumentation is included in the payloads of two Nike Apache sounding rockets used in an investigation of energetic particle fluxes. The data from an array of solid-state detectors and an electrostatic analyzer is processed to give the energy spectrum as a function of pitch angle. The experiment performed well in its first flight test: Nike Apache 14.543 was launched from Wallops Island at 2315 EST on 19 June 1978. The system was designed to be easily adaptable to other data-manipulation requirements and some suggestions for further development are included
Mariner Mars 1971 spacecraft destruct unit
Shaped charge destruct unit for Mariner Mars 1971 spacecraf
Configurations of Handles and the Classification of Divergences in the String Partition Function
The divergences that arise in the regularized partition function for closed
bosonic string theory in flat space lead to three types of perturbation series
expansions, distinguished by their genus dependence. This classification of
infinities can be traced to geometrical characteristics of the string
worldsheet. Some categories of divergences may be eliminated in string theories
formulated on compact manifolds.Comment: 24 pages, DAMTP-R/94/1
The Effects of Private Self-Consciousness and Perspective Taking on Satisfaction in Close Relationships.
131 heterosexual student couples, aged 17–32 yrs, 30 of whom were married or engaged answered questions concerning themselves and their relationships. It was predicted that individual differences in private self-consciousness would be positively related to relationship satisfaction because of the greater self-disclosure resulting from that heightened self-attention. It was further predicted that individual differences in perspective taking would foster relationship satisfaction, independent of any influence of self-disclosure. Both expectations were confirmed. Scores on the private self-consciousness scale were predictive of reported self-disclosure, and self-disclosure was predictive of satisfaction in the relationship. Once the influence of self-disclosure was removed, no effect of self-consciousness on satisfaction remained. In contrast, after disclosure was controlled, perspective-taking scores were significantly related to satisfaction and were in fact unrelated to disclosure at all. Findings indicate that 2 personality characteristics having to do with habitual attention to behavioral tendencies, emotions, and motivations significantly enhance the quality of close heterosexual relationships in different ways
Chiral approach to antikaon s- and p-wave interactions in dense nuclear matter
The properties of the antikaons in nuclear matter are investigated from a
chiral unitary approach which incorporates the s- and p-waves of the interaction. To obtain the in-medium meson-baryon amplitudes we include,
in a self-consistent way, Pauli blocking effects, meson self-energies corrected
by nuclear short-range correlations and baryon binding potentials. We pay
special attention to investigating the validity of the on-shell factorization,
showing that it cannot be applied in the evaluation of the in-medium
corrections to the p-wave amplitudes. In nuclear matter at saturation energy,
the and develop an attractive potential of about -30 MeV,
while the pole remains at the free space value although its width
gets sensibly increased to about 80 MeV. The antikaon also develops a moderate
attraction that does not support the existence of very deep and narrow bound
states, confirming the findings of previous self-consistent calculations.Comment: 29 pages, 12 figures, published in Physical Review
Introduction to orbital flight planning (1)
This workbook is designed for students interested in space flight planning, who after training, may serve as flight planning aides. Routine flight planning activities requiring engineering-type calculations and analysis are covered. Practice exercises and brief instructions are given for the programming and use of the hand calculator as well as the calculation of position and velocity in the orbital plane. Calculation of relative orbital position is also covered with emphasis upon celestial coordinates and time measurement
A Catalog of Galaxy Clusters Observed by XMM-Newton
Aims: We present a uniform catalog of the images and radial profiles of the
temperature, abundance, and brightness for 70 clusters of galaxies observed by
XMM-Newton.
Methods: We use a new "first principles" approach to the modeling and removal
of the background components; the quiescent particle background, the cosmic
diffuse emission, the soft proton contamination, and the solar wind charge
exchange emission. Each of the background components demonstrate significant
spectral variability, several have spatial distributions that are not described
by the photon vignetting function, and all except for the cosmic diffuse
emission are temporally variable. Because these backgrounds strongly affect the
analysis of low surface brightness objects, we provide a detailed description
our methods of identification, characterization, and removal.
Results: We have applied these methods to a large collection of XMM-Newton
observations of clusters of galaxies and present the resulting catalog. We find
significant systematic differences between the Chandra and XMM-Newton
temperatures.Comment: Accepted for publication in A&A, 55 pages with 42 figure
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