2,012 research outputs found
Strategic Interaction and Trade Policymaking: Formal Analysis and Simulation
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73499/1/j.1467-9701.2006.00797.x.pd
Real Time Data Acquisition: Recommendations for the Medical Information Bus (MIB)
journal articleBiomedical Informatic
Observations of Hierarchical Solar-Type Multiple Star Systems
Twenty multiple stellar systems with solar-type primaries were observed at
high angular resolution using the PALM-3000 adaptive optics system at the 5 m
Hale telescope. The goal was to complement the knowledge of hierarchical
multiplicity in the solar neighborhood by confirming recent discoveries by the
visible Robo-AO system with new near-infrared observations with PALM-3000. The
physical status of most, but not all, of the new pairs is confirmed by
photometry in the Ks band and new positional measurements. In addition, we
resolved for the first time five close sub-systems: the known astrometric
binary in HIP 17129AB, companions to the primaries of HIP 33555, and HIP
118213, and the companions to the secondaries in HIP 25300 and HIP 101430. We
place the components on a color-magnitude diagram and discuss each multiple
system individually.Comment: Accepted to Astronomical Journa
NORMALITY VERSUS COUNTABLE PARACOMPACTNESS IN PERFECT SPACES
This is the published version, also available here: http://www.dx.doi.org/10.1090/S0002-9904-1976-14150-X. First published in Bull. AMS. in 1976, published by the American Mathematical Society
Anodic Dissolution Of Zinc In Potassium Nitrate
The apparent valence of pure zinc dissolving anodically in 3% KNO3 was determined as a function of current density, temperature, and ultrasonic agitation. The apparent valence of zinc dissolving anodically at 24°C diminishes from 2.01 ± 0.01 at low current densities to 1.86 at about 50 ma and remains fairly constant up to about 80 ma cm−2. This valence is affected to some extent by the preparation, e.g., polishing of the electrode, but is independent of its structure (mono- or polycrystal). Ultrasonic vibrations do not influence the apparent valence at high current densities. In all cases a black film (corrosion product) spalls off the anode but to a larger extent with ultrasonics. The apparent valence decreases with increasing temperature (measurements between 25° and 68°C) and again with increasing current density, and appears to vary as a function of metal history. Fine metallic Zn particles are found in the dark corrosion product. The average size of the particles increases with increasing temperature. On the basis of the above, it is concluded that the normal valency of zinc ions, +2, does not change during anodic dissolution in nitrate solutions, but the apparent valence of less than 2 arises as a consequence of increased local corrosion and of surface disintegration of the anode. Both occur outside the electrical circuit thus accounting for the lower coulombic equivalent. A mechanism for the disintegration phenomenon is presented. © 1967, The Electrochemical Society, Inc. All rights reserved
The Mechanism Of The Electrooxidation Of Acetylene On Gold
Acetylene has been oxidized anodically in aqueous solutions at 80 °C on gold electrodes. It was found that the partial oxidation to CO2 was accompanied by a polymer formation. Effects of potential, acetylene partial pressure, pH, and temperature on the rate (current) were measured. A discontinuity in the Tafel curves was noted that indicated a change in the reaction mechanism with potential. The discontinuity was also pH dependent. A mechanism involving the discharge of H2O and/or OH− has been proposed that is consistent with the experimental results. © 1967, The Electrochemical Society, Inc. All rights reserved
Know the Star, Know the Planet. III. Discovery of Late-Type Companions to Two Exoplanet Host Stars
We discuss two multiple star systems that host known exoplanets: HD 2638 and
30 Ari B. Adaptive optics imagery revealed an additional stellar companion to
both stars. We collected multi-epoch images of the systems with Robo-AO and the
PALM-3000 adaptive optics systems at Palomar Observatory and provide relative
photometry and astrometry. The astrometry indicates that the companions share
common proper motion with their respective primaries. Both of the new
companions have projected separations less than 30 AU from the exoplanet host
star. Using the projected separations to compute orbital periods of the new
stellar companions, HD 2638 has a period of 130 yrs and 30 Ari B has a period
of 80 years. Previous studies have shown that the true period is most likely
within a factor of three of these estimated values. The additional component to
the 30 Ari makes it the second confirmed quadruple system known to host an
exoplanet. HD 2638 hosts a hot Jupiter and the discovery of a new companion
strengthens the connection between hot Jupiters and binary stars. We place the
systems on a color-magnitude diagram and derive masses for the companions which
turn out to be roughly 0.5 solar mass stars.Comment: Accepted to Astronomical Journal, 16 pages, 5 Figure
Managing fire-prone forests in the western United States
The management of fire-prone forests is one of the most controversial natural resource issues in the US today, particularly in the west of the country. Although vegetation and wildlife in these forests are adapted to fire, the historical range of fire frequency and severity was huge. When fire regimes are altered by human activity, major effects on biodiversity and ecosystem function are unavoidable. We review the ecological science relevant to developing and implementing fire and fuel management policies for forests before, during, and after wildfires. Fire exclusion led to major deviations from historical variability in many dry, low-elevation forests, but not in other forests, such as those characterized by high severity fires recurring at intervals longer than the period of active fire exclusion. Restoration and management of fire-prone forests should be precautionary, allow or mimic natural fire regimes as much as possible, and generally avoid intensive practices such as post-fire logging and planting
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