97,902 research outputs found
Solubility data are compiled for metals in liquid zinc
Available data is compiled on the solubilities of various metals in liquid zinc. The temperature dependence of the solubility data is expressed using the empirical straight line relationship existing between the logarithm of the solubility and the reciprocal of the absolute temperature
Gravity stabilized flying vehicle Patent
Hovering type flying vehicle design and principle mechanisms for manned or unmanned us
Model for Estimating the Probability of Crop Production for Ginkgo biloba L.
Mature female Maidenhair trees (Ginkgo biloba L.)have been observed to produce seed dispersal units in some years and none in other years. A temperature and/or photoperiod flowering threshold is suggested. Daily temperatures and daylengths at five Ginkgo sites in continental U.S. for January-April 1964-1974 were evaluated. A computer program was designed to estimate daily photothermal equivalent (PTE = temperature and photoperiod), and the magnitude and duration of the PTE in relation to a series of photothermal constants. Use of the data from production and nonproduction years provided a mathematical model for prediction of dispersal unit production. The model was tested with environmental data for additional sites recorded in the botanical literature
Training vehicle for controlling attitude Patent
Attitude control training device for astronauts permitting friction-free movement with five degrees of freedo
Aiming for ultra-scalable ePortfolio distribution using peer-to-peer networks
In this paper the authors discuss how peer-to-peer technology offers a practical solution to building highly scalable Europe-wide and worldwide ePortfolio networks over existing network infrastructures.This solution also offers the effect of empowering individuals through moving the management and storage responsibilities onto the portfolio owners, decoupling users from any single institutional ePortfolio service provider The authors do not present this solution as the single way forward, but as an alternative to what is seen as a mainly client-server and Web-based approach to ePortfolio development, and to encourage developers to explore the possibilities for ePortfolio integration with emerging and relatively immature technologies. A prototype implementation is reported and future developments described
Subgravity simulator Patent
Apparatus for training astronaut crews to perform on simulated lunar surface under conditions of lunar gravit
Demographic Trends in National Forest, Recreational, Retirement, and Amenity Areas
Those who live near national forests are both potential forest visitors and neighbors who feel the impact of many forest management decisions. This paper provides some insights about those proximate populations. It does so by measuring the proportion of national forest land within each county and then combining that with an analysis of the patterns of demographic change over the past several decades. Because there is considerable overlap between counties that contain national forests and those designated as recreational, high amenity, and retirement destination counties, demographic trends in such counties are compared. A total of 757 of the 3,141 U.S. counties contain national forest land. More than 66.1 million people resided in these counties in 2000, some 24% of the U.S. total. The population in national forest counties grew by 19% between 1990 and 2000 compared to 13% for the nation as a whole. Most of the population gain in national forest areas resulted from net in-migration. Population gains in national forest counties were slightly smaller than those in recreational and natural amenity counties and significantly less than those in retirement destination counties; however, the gains were considerably larger than those in other counties. National forest counties that are metropolitan have significantly more Hispanics than other metropolitan counties but fewer Blacks and Whites. Nonmetropolitan national forest counties contain a much larger proportion of non-Hispanic Whites than their metropolitan counterparts, a finding consistent with that for nonmetropolitan counties in general. Knowledge about the changing size and demographic structure of the population in national forest counties has particular relevance to Forest Service planners and policymakers
Oxygen and Sodium Abundances in M13 (NGC 6205) Giants: Linking Globular Cluster Formation Scenarios, Deep Mixing, and Post-RGB Evolution
We present O, Na, and Fe abundances, as well as radial velocities, for 113
red giant branch (RGB) and asymptotic giant branch (AGB) stars in the globular
cluster M13. The abundances and velocities are based on spectra obtained with
the WIYN-Hydra spectrograph, and the observations range in luminosity from the
horizontal branch (HB) to RGB-tip. The results are examined in the context of
recent globular cluster formation scenarios. We find that M13 exhibits many key
characteristics that suggest its formation and chemical enrichment are
well-described by current models. Some of these observations include: the
central concentration of O-poor stars, the notable decrease in [O/Fe] (but
small increase in [Na/Fe]) with increasing luminosity that affects primarily
the "extreme" population, the small fraction of stars with halo-like
composition, and the paucity of O-poor AGB stars. In agreement with recent
work, we conclude that the most O-poor M13 giants are likely He-enriched and
that most (all?) O-poor RGB stars evolve to become extreme HB and AGB-manqu\'e
stars. In contrast, the "primordial" and "intermediate" population stars appear
to experience standard HB and AGB evolution.Comment: Accepted for publication in The Astrophysical Journal Letters. 18
pages; 3 figures; 1 tabl
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