Space environmental effects: Construction and utilization of a system to measure low thermal strain in one meter graphite epoxy tubes

A system for measuring the expansion of low coefficient of thermal expansion (CTE) materials was constructed around a H.P. 5526-A laser measuring system. The vacuum CTE measurements in the -150 F to +120 F range were made over a 6 month period on a graphite epoxy tube yielding CTE values of 2.5 to one fifty-millionth/F above ambient and 2 + or - one ten-millionth F below ambient temperature. To assure that the below ambient, approximately 10 microns high open loop nature of the delta L/L vs. T curves was not apparatus related, similar size quartz tubes (A and B) were checked and found to have only a 2 micron (negligable for quartz) open loop component. These two quartz tubes, A and B, had ambient CTE values 20% and 45% respectively higher than the average handbook value. The overnight microcreep diminished an order of magnitude during the first several cycles after the system had been reopened

Chemical treatment makes aromatic polyamide fabric fireproof in oxygen atmosphere

Organic fabric is reacted first with vapors of a phosphorus oxychloride, phosphorus oxybromide solution and then with bromine vapor, after neutralization it is flameproof in pure oxygen atmosphere. Soaking the fabric with mixture of ammonium polyphosphates increases flame resistance, but the polyphosphates are leached out during laundering

LDEF solar cell radiation effects analysis

Because of the extended time that the Long Duration Exposure Facility (LDEF) mission stayed in space, the solar cells on the satellite experienced greater environments than originally planned. The cells showed an overall degradation in performance that is due to the combined effects of the various space environments. The purpose of this analysis is to calculate the effect of the accumulated radiation on the solar cells, thereby helping Marshall Space Flight Center (MSFC) to unravel the relative power degradation from the different environments

Gender And Executive Pay In The S&P Mid-Cap And Small-Cap Companies

Gender pay equity among all levels of workers is a topic of interest to the public as well as to business researchers. Catalyst, a non-profit group devoted to the advancement of women in management, noted that women executives were paid only 68% of the earnings of their male counterparts in 1997. In this current study of the S&P Mid-Cap and Small-Cap companies, we find that variations in annual and long-term executive pay are generally not associated with gender, but rather with the size of the company, CEO pay (a control for pay-scale strategy), and whether the executive is in a line position. While women appear to be earnings equal amounts of total remuneration in these smaller companies, it should be noted that only 3.6% of the S&P Mid-Cap and Small-Cap five top-paid executives were female in 1998

A technique for improving the germinability of grape seeds for breeding purposes

A method, using bunches from pre-rooted cuttings which are defoliated very early during bud burst, allows the cultivation of fruiting plants in the glasshouse. The germinability of the seeds obtained in this way is improved, which permits, in particular, progenies of an early mutant of the cultivar "Cot", the seeds of which obtained in the field do practically never germinate.Une technique pour améliorer la germinabilité des graines de vigne pour les besoinsde l'améliorationUne technique, consistant à obtenir des grappes sur des boutures préenracinées puis soumises à un effeuillage très précoce au débourrement, permet de cultiver des plantes fructifères en serre. Les graines ainsi obtenues ont une proportion de germination meilleure, ce qui a permis en particulier d'obtenir des descendants d'un mutant précoce du Cot dont les graines obtenues au champ ne germent pratiquement jamais.

Estrategias, estilos de dirección, compromiso de los trabajadores, responsabilidad social y desempeño de las pequeñas y medianas empresas de economía social de la región de Murcia

In the Region of Murcia are located about three thousand five hundred companies of Social Economy (U.S.), mostly small and medium enterprises (SMEs). The aim of this study was to determine their level of professionalism and efficiency in the regional context. The analysis of the data generated by a survey of a hundred company´s managers in the region, allows us to describe relevant aspects of their internal and external operations, including: leadership styles, level of worker commitment, entrepreneurial skills, competitive strategies, levels of social responsibility or results of each company. The classification of the surveyed companies meeting their results in recent years marked by the economic crisis and the improvement in the performance of various organizational aspects, allows us to propose an entrepreneurial typology and to check the relationship between business accomplishments and leadership styles, the level of commitment of workers or monitoring of certain innovative business strategies.En la Región de Murcia se localizan cerca de tres mil quinientas empresas de Economía Social (ES), en su mayor parte Pequeñas y Medianas Empresas (PYMEs). El objetivo de este trabajo es conocer el nivel de profesionalización y eficacia de las mismas. El análisis de los datos generados con una encuesta realizada a un centenar de gerentes de empresas de la Región, permite describir aspectos relevantes de su funcionamiento interno y externo, como son: estilos de liderazgo, nivel de compromiso de los trabajadores, capacidades empresariales, estrategias competitivas, niveles de responsabilidad social o resultados de cada empresa. La realización de una clasificación de las empresas encuestadas atendiendo a sus resultados en los últimos años de crisis económica y mejoras en el desempeño de distintos aspectos organizacionales, permite plantear una tipología empresarial, comprobándose la relación que existe entre sus logros empresariales y los estilos de liderazgo, el nivel de compromiso de los trabajadores o el seguimiento de determinadas estrategias empresariales más innovadoras

Rank-(n – 1) convexity and quasiconvexity for divergence free fields

The CAST experiment at CERN (European Organization of Nuclear Research) searches for axions from the sun. The axion is a pseudoscalar particle that was motivated by theory thirty years ago, with the intention to solve the strong CP problem. Together with the neutralino, the axion is one of the most promising dark matter candidates. The CAST experiment has been taking data during the last two years, setting an upper limit on the coupling of axions to photons more restrictive than from any other solar axion search in the mass range below 0.1 eV. In 2005 CAST will enter a new experimental phase extending the sensitivity of the experiment to higher axion masses. The CAST experiment strongly profits from technology developed for high energy physics and for X-ray astronomy: A superconducting prototype LHC magnet is used to convert potential axions to detectable X-rays in the 1-10 keV range via the inverse Primakoff effect. The most sensitive detector system of CAST is a spin-off from space technology, a Wolter I type X-ray optics in combination with a prototype pn-CCD developed for ESA's XMM-Newton mission. As in other rare event searches, background suppression and a thorough shielding concept is essential to improve the sensitivity of the experiment to the best possible. In this context CAST offers the opportunity to study the background of pn-CCDs and its long term behavior in a terrestrial environment with possible implications for future space applications. We will present a systematic study of the detector background of the pn-CCD of CAST based on the data acquired since 2002 including preliminary results of our background simulations.Comment: 11 pages, 8 figures, to appear in Proc. SPIE 5898, UV, X-Ray, and Gamma-Ray Space Instrumentation for Astronomy XI

Using a zoom lens in monocular vision for 3D reconstruction

Using a zoom Zens in monocular vision seems to be an interesting idea. The principal aim of this article is to prove that it is possible to infer 3D information from a set of images tak'en with a zoom lens . In the first part of this article, a precise study of the optical properties of such a lens gives the two following major results - The intersection between the optical axis and the image plane can be independently and accurately determined, - the pin-hole model can be used for the zoom lens only if the object-toimage distance is not considered as fixed .Then, ta explain the optical phenomena occurring during a focal length change, we show that a thick optical model must be considered. Finally, experimental results of reconstruction, from a set of real images, are given .L'utilisation d'un zoom en vision monoculaire, en vue de la reconstruction tridimensionnelle d'un univers observé, nous paraît une idée intéressante. En effet les propriétés optiques d'un objectif à focale variable permettent de déterminer, facilement et avec précision, les coordonnées de l'intersection de l'axe optique et du plan image, mais également de concevoir une reconstruction par triangulation. Dans cet article, nous montrons que l'approximation de cet objectif par le modèle sténopé nécessite de ne plus considérer la distance entre l'objet et le plan image comme un paramètre fixe. Afin d'appréhender plus globalement les phénomènes optiques mis en jeu par la variation de distance focale, il est alors nécessaire de recourir au modèle optique épai