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These publications showcase the significant science conducted in our Science Centers.

Filter Total Items: 16727

Bauxite and alumina Bauxite and alumina

The article discusses the latest developments in the bauxite and alumina industry, particularly in the U.S., as of June 2011. It claims that the U.S. mainly relies on imports for its bauxite consumption. Several states, including Alabama, Arkansas and Georgia, however, produce small amounts of bauxite and bauxitic clays for nonmetallurgical purposes. The major exporters of alumina to the...
Authors
E.L. Bray

Diatomite Diatomite

The United States continues to be the world's leading producer and consumer of diatomite. Production of diatomite in the United States during 2010 was estimated to be 550 kt (606,000 st), a 4-percent decrease compared with 2009 production.
Authors
R.D. Crangle

Methane hydrates and contemporary climate change Methane hydrates and contemporary climate change

As the evidence for warming climate became better established in the latter part of the 20th century (IPCC 2001), some scientists raised the alarm that large quantities of methane (CH4) might be liberated by widespread destabilization of climate-sensitive gas hydrate deposits trapped in marine and permafrost-associated sediments (Bohannon 2008, Krey et al. 2009, Mascarelli 2009). Even if...
Authors
Carolyn D. Ruppel

Mineral resource of the month: indium Mineral resource of the month: indium

Geologically, the occurrence of indium minerals is rare. The element most often occurs as a sulfide inclusion or substitutes in other base-metal minerals, including cassiterite, chalcopyrite, sphalerite and stannite. Indium’s abundance in the crust is estimated to be 0.05 parts per million, which makes it more abundant than silver, but it is so widely disseminated that it does not occur...
Authors
Amy C. Tolcin

Glacial influence on the geochemistry of riverine iron fluxes to the Gulf of Alaska and effects of deglaciation Glacial influence on the geochemistry of riverine iron fluxes to the Gulf of Alaska and effects of deglaciation

Riverine iron (Fe) derived from glacial weathering is a critical micronutrient source to ecosystems of the Gulf of Alaska (GoA). Here we demonstrate that the source and chemical nature of riverine Fe input to the GoA could change dramatically due to the widespread watershed deglaciation that is underway. We examine Fe size partitioning, speciation, and isotopic composition in tributaries...
Authors
A.W. Schroth, John Crusius, F. Chever, B.C. Bostick, O.J. Rouxel

Water chemistry and its effects on the physiology and survival of Atlantic salmon Salmo salar smolts Water chemistry and its effects on the physiology and survival of Atlantic salmon Salmo salar smolts

The physiological effects of episodic pH fluctuations on Atlantic salmon Salmo salar smolts in eastern Maine, U.S.A., were investigated. During this study, S. salar smolts were exposed to ambient stream‐water chemistry conditions at nine sites in four catchments for 3 and 6 day intervals during the spring S. salar smolt migration period. Plasma chloride, plasma glucose, gill aluminium...
Authors
T. Liebich, S. D. McCormick, D. Kircheis, Kevin Johnson, R. Regal, T. Hrabik

Sensitivity of Pliocene ice sheets to orbital forcing Sensitivity of Pliocene ice sheets to orbital forcing

The stability of the Earth's major ice sheets is a critical uncertainty in predictions of future climate and sea level change. One method of investigating the behaviour of the Greenland and the Antarctic ice sheets in a warmer-than-modern climate is to look back at past warm periods of Earth history, for example the Pliocene. This paper presents climate and ice sheet modelling results...
Authors
A.M. Dolan, A.M. Haywood, D.J. Hill, H.J. Dowsett, S.J. Hunter, D.J. Lunt, S.J. Pickering

Rayleigh-based, multi-element coral thermometry: A biomineralization approach to developing climate proxies Rayleigh-based, multi-element coral thermometry: A biomineralization approach to developing climate proxies

This study presents a new approach to coral thermometry that deconvolves the influence of water temperature on skeleton composition from that of “vital effects”, and has the potential to provide estimates of growth temperatures that are accurate to within a few tenths of a degree Celsius from both tropical and cold-water corals. Our results provide support for a physico-chemical model of...
Authors
G.A. Gaetani, A.L. Cohen, Z. Wang, John Crusius

Using a semi-natural stream to produce young sturgeons for conservation stocking: Maintaining natural selection during spawning and rearing Using a semi-natural stream to produce young sturgeons for conservation stocking: Maintaining natural selection during spawning and rearing

Young sturgeons used for conservation stocking are presently produced using the same methods used for commercial culture. To determine if young sturgeons could be produced without relaxing natural selection factors, we developed a semi‐natural stream where we annually studied mating of wild shortnose sturgeon (Acipenser brevirostrum) observed movement of gametes released freely during...
Authors
B. Kynard, D. Pugh, T. Parker, Micah Kieffer

Structural stability of methane hydrate at high pressures Structural stability of methane hydrate at high pressures

The structural stability of methane hydrate under pressure at room temperature was examined by both in-situ single-crystal and powder X-ray diffraction techniques on samples with structure types I, II, and H in diamond-anvil cells. The diffraction data for types II (sII) and H (sH) were refined to the known structures with space groups Fd3m and P63/mmc, respectively. Upon compression, sI...
Authors
J. Shu, X. Chen, I-Ming Chou, W. Yang, Jiawen Hu, R.J. Hemley, Ho-kwang Mao

Comparative performance of CO2 measuring methods: marine aquaculture recirculation system application Comparative performance of CO2 measuring methods: marine aquaculture recirculation system application

Many methods are available for the measurement of dissolved carbon dioxide in an aqueous environment. Standard titration is the typical field method for measuring dissolved CO2 in aquaculture systems. However, titrimetric determination of dissolved CO2 in marine water aquaculture systems is unsuitable because of the high dissolved solids, silicates, and other dissolved minerals that...
Authors
T.J. Pfeiffer, S.T. Summerfelt, B.J. Watten

Large-scale flow experiments for managing river systems Large-scale flow experiments for managing river systems

Experimental manipulations of streamflow have been used globally in recent decades to mitigate the impacts of dam operations on river systems. Rivers are challenging subjects for experimentation, because they are open systems that cannot be isolated from their social context. We identify principles to address the challenges of conducting effective large-scale flow experiments. Flow...
Authors
Christopher P. Konrad, Julian D. Olden, David A. Lytle, Theodore S. Melis, John C. Schmidt, Erin N. Bray, Mary Freeman, Keith B. Gido, Nina P. Hemphill, Mark J. Kennard, Laura E. McMullen, Meryl C. Mims, Mark Pyron, Christopher T. Robinson, John G. Williams
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