Publications
These publications showcase the significant science conducted in our Science Centers.
Filter Total Items: 16904
Mineral resource of the month: nickel Mineral resource of the month: nickel
Together with chromium, nickel makes steel more resistant to corrosion. Stainless steel thus accounts for more than 65 percent of primary nickel consumption in the world. One of the more common grades of stainless steel is Type 304, which contains 18 to 20 percent chromium and 10.5 to 12 percent nickel. Owing to their high corrosion resistance, nickel-bearing stainless steels are widely...
Authors
Peter H. Kuck
Mineral resource of the month: beryllium Mineral resource of the month: beryllium
Beryllium metal is lighter than aluminum and stiffer than steel. These and other properties, including its strength, dimensional stability, thermal properties and reflectivity, make it useful for aerospace and defense applications, such as satellite and space-vehicle structural components. Beryllium’s nuclear properties, combined with its low density, make it useful as a neutron...
Authors
Kim B. Shedd
Mineral resource of the month: barite Mineral resource of the month: barite
Also called barytes, barite forms in various geologic environments and is frequently found with both metallic and nonmetallic minerals. Most barite is produced by open-pit mining techniques, and most crude barite requires some upgrading to meet minimum purity or specific gravity levels.
Authors
M. Michael Miller
Kaolin Kaolin
In 2005, 22 companies mined kaolin in nine US states. Production in Georgia declined to 6.19 Mt down from 6.78 Mt in 2004. Despite the decline, Georgia remained the leading producer state followed by Alabama, South Carolina, Arkansas, Texas, Nevada, California, North Carolina and Florida. In the next year or two, domestic and export sales of kaolin for paper application are not expected...
Authors
R.L. Virta
Water Resources Data, Pennsylvania, Water Year 2005, Volume 1. Delaware River Basin Water Resources Data, Pennsylvania, Water Year 2005, Volume 1. Delaware River Basin
Water resources data for the 2005 water year for Pennsylvania consist of records of discharge and water quality of streams; contents and elevations of lakes and reservoirs; and water levels and water quality of ground-water wells. This report, Volume 1 contains (1) discharge records for 75 continuous-record streamflow-gaging stations, 5 partial-record stations, 41 special-study and...
Authors
R.R. Durlin, W.P. Schaffstall, M.R. Beaver
Assessing recreation impacts to cliffs in Shenandoah National Park: Integrating visitor observation with trail and recreation site measurements Assessing recreation impacts to cliffs in Shenandoah National Park: Integrating visitor observation with trail and recreation site measurements
The rock outcrops and cliffs of Shenandoah National Park provide habitat for several rare and endangered plant and animal species, including the federally endangered Shenandoah Salamander (Plethodon shenandoah; Ludwig et al., 1993). The location of the well-known park tour road, Skyline Drive, along the ridgeline provides exceptional access to many outcrops and cliffs throughout the park...
Authors
K.T. Wood, S.R. Lawson, J. L. Marion
Assessing tiger population dynamics using photographic capture-recapture sampling Assessing tiger population dynamics using photographic capture-recapture sampling
Although wide-ranging, elusive, large carnivore species, such as the tiger, are of scientific and conservation interest, rigorous inferences about their population dynamics are scarce because of methodological problems of sampling populations at the required spatial and temporal scales. We report the application of a rigorous, noninvasive method for assessing tiger population dynamics to...
Authors
K. U. Karanth, J.D. Nichols, S. Kumar, J.E. Hines
A new species of the genus Centrolene (Amphibia : Anura : Centrolenidae) from Ecuador with comments on the taxonomy and biogeography of Glassfrogs A new species of the genus Centrolene (Amphibia : Anura : Centrolenidae) from Ecuador with comments on the taxonomy and biogeography of Glassfrogs
We describe a new species of Glassfrog, Centrolene mariaelenae n. sp., from the Contrafuerte de Tzunantza, southeastern Ecuador. The new species is assigned to the Centrolene gorzulai species group, a clade previously known only from the Guayana Shield region, because the parietal peritoneum is transparent and the hepatic peritoneum is covered by guanophores. We analyze the diversity...
Authors
D.F. Cisneros-Heredia, R.W. McDiarmid
Variation in probability of first reproduction of Weddell seals Variation in probability of first reproduction of Weddell seals
Summary 1. For many species, when to begin reproduction is an important life-history decision that varies by individual and can have substantial implications for lifetime reproductive success and fitness. 2. We estimated age-specific probabilities of first-time breeding and modelled variation in these rates to determine age at first reproduction and understand why it varies in a...
Authors
G.L. Hadley, J.J. Rotella, R.A. Garrott, J.D. Nichols
Variation in Bachman's Sparrow home-range size at the Savannah River Site, South Carolina Variation in Bachman's Sparrow home-range size at the Savannah River Site, South Carolina
Using radiotelemetry, we studied variation in home-range size of the Bachman's Sparrow (Aimophila aestivalis) at the Savannah River Site (SRS), South Carolina, during the 1995 breeding season. At SRS, sparrows occurred primarily in two habitats: mature pine habitats managed for Red-cockaded Woodpecker (Picoides borealis) and pine plantations 1 to 6 years of age. The mean 95% minimum...
Authors
J.M. Stober, D.G. Krementz
Nest fate and productivity of American Oystercatchers, Cumberland Island National Seashore, Georgia Nest fate and productivity of American Oystercatchers, Cumberland Island National Seashore, Georgia
The American Oystercatcher (Haematopus palliatus) is listed as a species of high priority by the U.S. Shorebird Conservation Plan and is state-listed as rare in Georgia; however, biologists have not focused on identifying the causes of egg and hatchling losses. In 2003 and 2004, continuous video monitoring was used to document reproductive success of American Oystercatchers and identify...
Authors
J. B. Sabine, Sara H. Schweitzer, J.M. Meyers
A new species of arboreal toad (Anura : Bufonidae : Chaunus) from Madidi National Park, Bolivia A new species of arboreal toad (Anura : Bufonidae : Chaunus) from Madidi National Park, Bolivia
A new arboreal species of the Chaunus veraguensis group is described for the humid montane forest of Madidi National Park, in northern Bolivia. The new species differs from other species in the group by the combination small size, long and slender extremities, webbed hands, conspicuous tympanic membrane, well developed parotoid glands, absence of large glands on dorsum and extremities...
Authors
J.M. Padial, S. Reichle, R. McDiarmid, I. De la Riva