Two-plane balance and slip-ring design

A 3.25 cm (1.28 in.) two plane balance and eight channel slip ring assembly has been designed to measure and transmit the thrust (667-N;150-lb) and torque (135-N-m;100-lb-ft) components produced by wind tunnel model turboprops and drive motors operating at 300 Hz

The use of Planetary Nebulae precursors in the study of Diffuse Interstellar Bands

We present the first results of a systematic search for Diffuse Interstellar Bands in a carefully selected sample of post-AGB stars observed with high resolution optical spectroscopy. These stars are shown to be ideal targets to study this old, intriguing astrophysical problem. Our results suggest that the carrier(s) of these bands may not be present in the circumstellar environments of these evolved stars. The implications of the results obtained on the identification of the still unknown carrier(s) are discussed.Comment: 4 pages, 2 figures, proceedings of the conference 'Planetary Nebulae as Astrophysical Tools', held in Gdansk, Poland (June 28 - July 2, 2005

Spherical orbit closures in simple projective spaces and their normalizations

Let G be a simply connected semisimple algebraic group over an algebraically closed field k of characteristic 0 and let V be a rational simple G-module of finite dimension. If G/H \subset P(V) is a spherical orbit and if X is its closure, then we describe the orbits of X and those of its normalization. If moreover the wonderful completion of G/H is strict, then we give necessary and sufficient combinatorial conditions so that the normalization morphism is a homeomorphism. Such conditions are trivially fulfilled if G is simply laced or if H is a symmetric subgroup.Comment: 24 pages, LaTeX. v4: Final version, to appear in Transformation Groups. Simplified some proofs and corrected minor mistakes, added references. v3: major changes due to a mistake in previous version

Constraining the Accretion Geometry of the Intermediate Polar EX Hya Using NuSTAR, Swift, and Chandra Observations

In magnetically accreting white dwarfs, the height above the white dwarf surface where the standing shock is formed is intimately related with the accretion rate and the white dwarf mass. However, it is difficult to measure. We obtained new data with NuSTAR and Swift that, together with archival Chandra data, allow us to constrain the height of the shock in the intermediate polar EX Hya. We conclude that the shock has to form at least at a distance of about one white dwarf radius from the surface in order to explain the weak Fe Kα 6.4 keV line, the absence of a reflection hump in the high-energy continuum, and the energy dependence of the white dwarf spin pulsed fraction. Additionally, the NuSTAR data allowed us to measure the true, uncontaminated hard X-ray (12-40 keV) flux, whose measurement was contaminated by the nearby galaxy cluster Abell 3528 in non-imaging X-ray instruments.Fil: Luna, Gerardo Juan Manuel. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Mukai, K.. National Aeronautics and Space Administration; Estados UnidosFil: Orio, M.. Università di Padova; ItaliaFil: Zemko, P.. Università di Padova; Itali

Experiments with metallic and ceramic porous media

Work in the area of mechano-caloric phenomena was initiated during 1988 with startup in the Summer 1988 period. The ideal system utilizing He-II super-phenomena is modeled readily, within the frame of thermodynamics energetics, using the concept of an ideal superleak. The real system however uses porous media of non-ideal pore-grain ingredients. The early phase of experimental and related modeling studies is outlined for the time period from Summer 1988 to the end of 1988

Designing materials for electrochemical carbon dioxide recycling

Electrochemical carbon dioxide recycling provides an attractive approach to synthesizing fuels and chemical feedstocks using renewable energy. On the path to deploying this technology, basic and applied scientific hurdles remain. Integrating catalytic design with mechanistic understanding yields scientific insights and progresses the technology towards industrial relevance. Catalysts must be able to generate valuable carbon-based products with better selectivity, lower overpotentials and improved current densities with extended operation. Here, we describe progress and identify mechanistic questions and performance metrics for catalysts that can enable carbon-neutral renewable energy storage and utilization

Multi-wavelength study of the star-formation in the S237 H II region

We present a detailed multi-wavelength study of observations from X-ray, near-infrared to centimeter wavelengths to probe the star formation processes in the S237 region. Multi-wavelength images trace an almost sphere-like shell morphology of the region, which is filled with the 0.5--2 keV X-ray emission. The region contains two distinct environments - a bell-shaped cavity-like structure containing the peak of 1.4 GHz emission at center, and elongated filamentary features without any radio detection at edges of the sphere-like shell - where {\it Herschel} clumps are detected. Using the 1.4 GHz continuum and $^{12}$CO line data, the S237 region is found to be excited by a radio spectral type of B0.5V star and is associated with an expanding H{\sc ii} region. The photoionized gas appears to be responsible for the origin of the bell-shaped structure. The majority of molecular gas is distributed toward a massive {\it Herschel} clump (M$_{clump}$ $\sim$260 M$_{\odot}$), which contains the filamentary features and has a noticeable velocity gradient. The photometric analysis traces the clusters of young stellar objects (YSOs) mainly toward the bell-shaped structure and the filamentary features. Considering the lower dynamical age of the H\,{\sc ii} region (i.e. 0.2-0.8 Myr), these clusters are unlikely to be formed by the expansion of the H\,{\sc ii} region. Our results also show the existence of a cluster of YSOs and a massive clump at the intersection of filamentary features, indicating that the collisions of these features may have triggered cluster formation, similar to those found in Serpens South region.Comment: 21 pages, 14 figures, 1 table, Accepted for publication in The Astrophysical Journa

Changes in pain-related beliefs, coping, and catastrophizing predict changes in pain intensity, pain interference, and psychological functioning in individuals with myotonic muscular dystrophy and facioscapulohumeral dystrophy

The primary aim of this study was to test hypothesized associations between changes in psychological variables (i.e., pain beliefs, catastrophizing and coping strategies) and changes in pain intensity and related adjustment (i.e., pain interference and psychological functioning) in individuals with Myotonic Muscular Dystrophy (MMD) and Facioscapulohumeral Muscular Dystrophy (FSHD). Methods: A sample of 107 adults with a diagnosis of MMD or FSHD, reporting pain in the past three months, completed assessments at two time-points, separated by about 24 months. Results showed that changes in pain-related psychological variables were significantly associated with changes in psychological functioning, pain intensity and pain interference. Specifically, increases in the belief that emotion influences pain, and catastrophizing were associated with decreases in psychological functioning. Increases in the coping strategies of asking for assistance and resting, and the increases of catastrophizing were associated with increases in pain intensity. Finally, increases in pain intensity and asking for assistance were associated with increases in pain interference. Discussion: The results support the utility of the biopsychosocial model of pain for understanding pain and its impact in individuals with MMD or FSHD. These findings may inform the design and implementation of psychosocial pain treatments for people with muscular dystrophy and chronic pain