Research Articles, Department of Geosciences
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Cell adhesion of Shewanella oneidensis to iron oxide minerals: Effect of different single crystal faces
(American Institute of Physics, 2005-12-30)The results of experiments designed to test the hypothesis that near-surface molecular structure of iron oxide minerals influences adhesion of dissimilatory iron reducing bacteria are presented. These experiments involved ... -
Nanotechnology: Nature's Gift or Scientists' Brainchild?
(The Royal Society of Chemistry, 2014-12-02)In the field of environmental nanotechnology, opinions on the novelty of engineered nanomaterials vary; some scientists believe that many engineered nanomaterials are indeed unique, while others are convinced that we are ... -
Texture and structural refinement using neutron diffraction data from molybdite (MoO3) and calcite (CaCO3) powders and a Ni-rich Ni50.7Ti49.30 alloy
(Cambridge University Press, 2009-12)Preferred orientation or texture is a common feature of experimental powder patterns. The mathematics of two commonly used models for preferred orientation-the March-Dollase and the generalized spherical-harmonic models-is ... -
In situ structural and texture analyses of monoclinic phase for polycrystalline Ni-rich T49.86Ni50.14 alloy from neutron diffraction data
(Cambridge University Press, 2008-03)Phase transformation temperatures of a polycrystalline Ni-rich Ti49.86Ni50.14 shape memory alloy were investigated using a differential scanning calorimeter. In situ structural and texture analyses of the monoclinic ... -
Structural refinement of neutron powder diffraction data of two-stage martensitic phase transformations in Ti50.75Ni47.75Fe1.50 shape memory alloy
(Cambridge University Press, 2007-09)Transformation behaviors of the technologically important polycrystalline Ti50.75Ni47.75Fe1.50 shape memory alloy were investigated using differential scanning calorimeter (DSC) and powder diffraction techniques. DSC ... -
Stability of zircon u-pb systematics in a greenschist-grade mylonite - an example from the rockfish valley fault zone, central Virginia, USA
(University of Chicago Press, 1992-09)The mid-Paleozoic, greenschist-grade Rockfish Valley Fault Zone (RVFZ) of central Virginia cuts the Grenville-aged Pedlar River Charnockite Suite (PRCS) and contains zircons that underwent brittle failure during ductile ... -
New Ediacara fossils preserved in marine limestone and their ecological implications
(Nature Publishing Group, 2014-02)Ediacara fossils are central to our understanding of animal evolution on the eve of the Cambrian explosion, because some of them likely represent stem-group marine animals. However, some of the iconic Ediacara fossils have ... -
Climate model boundary conditions for four Cretaceous time slices
(Copernicus Publications, 2007)General circulation models (GCMs) are useful tools for investigating the characteristics and dynamics of past climates. Understanding of past climates contributes significantly to our overall understanding of Earth's climate ... -
Cell adhesion of Shewanella oneidensis to iron oxide minerals: Effect of different single crystal faces
(American Institute of Physics, 2005-12)The results of experiments designed to test the hypothesis that near-surface molecular structure of iron oxide minerals influences adhesion of dissimilatory iron reducing bacteria are presented. These experiments involved ... -
Pressure impact on the structure, elasticity, and electron density distribution of CaSi2O5
(American Physical Society, 2013-05)Ab initio molecular dynamics simulations were used to reveal the mechanism of the fivefold to sixfold transition in Si coordination numbers of CaSi2O5. The longest first-neighbor Si-O distance drops from 2.8 to 1.8 angstrom ... -
Structural state of relaxor ferroelectrics PbSc0.5Ta0.5O3 and PbSc0.5Nb0.5O3 at high pressures up to 30 GPa
(American Physical Society, 2011-11-07)The pressure-induced structural changes in perovskite-type (ABO(3)) Pb-based relaxor ferroelectrics are studied on the basis of in situ single-crystal synchrotron x-ray diffraction and Raman scattering experiments on ... -
Pressure-induced structural transformations in pure and Ru-doped 0.9PbZn(1/3)Nb(2/3)O(3)-0.1PbTiO(3) near the morphotropic phase boundary
(American Physical Society, 2012-01-17)Pressure-induced structural transformations in relaxor-based perovskite-type (ABO(3)) 0.9PbZn(1/3)Nb(2/3)O(3)-0.1PbTiO(3) single crystals which have a very high piezoelectric response were studied by single-crystal x-ray ... -
First-principles study of several hypothetical silica framework structures
(American Physical Society, 1995-09-15)Several hypothetical silica structures have been generated using a simulated-annealing strategy with an ab initio based covalent-bonding potential. First-principles total-energy pseudopotential methods have been used to ... -
Effect of Ba incorporation on pressure-induced structural changes in the relaxor ferroelectric PbSc0.5Ta0.5O3
(American Physical Society, 2009-09-28)Pressure-induced structural changes in the canonical relaxor Pb0.78Ba0.22Sc0.5Ta0.5O3 were studied with both in-house and synchrotron single-crystal x-ray diffraction as well as Raman spectroscopy at pressures up to 9.8 ... -
Effect of La doping on the ferroic order in Pb-based perovskite-type relaxor ferroelectrics
(American Physical Society, 2011-04-07)The structural alteration induced by the substitution of three-valent cations with an isotropic electronic outermost shell for Pb2+ in perovskite-type relaxors was investigated in the solid solutions Pb1-xLaxSc(1+x)/2Ta(1-x)/2O3, ... -
A-site doping-induced renormalization of structural transformations in the PbSc0.5Nb0.5O3 relaxor ferroelectric under high pressure
(American Physical Society, 2010-05-01)The effect of A-site incorporated Ba2+ and Bi3+ on the pressure-driven structural transformations in Pb-based perovskite-type relaxor ferroelectrics has been studied with in situ x-ray diffraction and Raman scattering of ... -
Constraints on the S wave velocity structure in a continental shield from surface wave data: Comparing linearized least squares inversion and the direct search Neighbourhood Algorithm
(American Geophysical Union, 2002-05)[1] In their study of upper mantle structure beneath the Parana Basin of SE Brazil, Snoke and James [1997] concluded, on the basis of a linearized least squares inversion (LLSI) of surface wave dispersion data, that a ... -
Lithospheric structure of the Chaco and Parana Basins of South America from surface-wave inversion
(American Geophysical Union, 1997-02)Surface-wave data from a portable broadband array have been used to invert for the velocity structure of the crust and upper mantle beneath the Chaco and Parana Basins of central South America. The upper-mantle velocity ... -
Crustal thicknesses in SE Brazilian Shield by receiver function analysis: Implications for isostatic compensation
(American Geophysical Union, 2002-01)[1] The Brazilian Lithosphere Seismic Project (BLSP, a joint project by University of Sao Paulo and Carnegie Institution, 1992-1999) operated more than 20 temporary broadband stations in the southeastern Brazilian shield. ... -
Location of the southern edge of the Gorda slab and evidence for an adjacent asthenospheric window: Results from seismic profiling and gravity
(American Geophysical Union, 1998-12)As the Mendocino Triple Junction migrates northward along the California margin it is widely presumed to leave a "slab-free" or "asthenospheric" window in its wake. A 250-km-long south-north seismic refraction-reflection ...
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