Physical Sciences and Mathematics | Open Access Articles

Distributions Of Nobel Metal Pd And Pt In Mesoporous Silica, J. Arbiol, A. Cabot, J. R. Morante, Fanglin Chen, Meilin Liu

Faculty Publications

Mesoporous silicananostructures have been synthesized and loaded with Pd and Pt catalytic noble metals. It is found that Pd forms small nanoclusters (3–5 nm) on the surface of the mesoporous structure whereas Pt impregnation results in the inclusion of Pt nanostructures within the silica hexagonal pores (from nanoclusters to nanowires). It is observed that these materials have high catalyticproperties for CO–CH₄CO–CH₄CO–CH₄combustion, even in a thick film form. In particular, results indicate that the Pt and Pd dispersed in mesoporous silica are catalytically active as a selective filter for gas sensors.

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Volcanic Mound Fields On The East Pacific Rise, 16˚-19˚S: Low Effusion Rate Eruptions At Overlapping Spreading Centers For The Past 1 Myr, Scott M. White, Ken C. Macdonald, John Sinton

Faculty Publications

Volcanic mound fields identified on SeaMARC II and HMR1 12 kHz side-scan data from the southern East Pacific Rise (SEPR) occur near overlapping spreading centers (OSCs) and migration traces of OSCs. The volcanic mound fields appear as a distinctive hummocky seafloor fabric due to side-scan backscatter reflections from clusters of moundshaped reflectors. The lack of growth of the mound fields away from the ridge axis, and their occurrence in association with OSC traces, suggests that mound fields form along the ridge crest near OSCs. Volcanic mound fields are found where 120 kHz side-scan and visual observations find fields of pillow …

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Seismic Experiments Target Earthquake-Prone Region In Romania, F Hauser, C Prodehl, M Landes, A Bala, V Raileanu, J Bribach, James H. Knapp, Camelia C. Diaconescu, C Dinu, V Mocanu, W Fielitz, S Harder, G. Randy Keller, E Hegedues, R A. Stephenson

Faculty Publications

No abstract provided.

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An Extension Of Elton's L(1)(N) Theorem To Complex Banach Spaces, S J. Dilworth, Joseph P. Patterson

Faculty Publications

No abstract provided.

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Correlation Between Volcanic And Tectonic Segmentation Of Fast-Spreading Ridges: Evidence From Volcanic Structures And Lava Flow Morphology On The East Pacific Rise At 9˚-10˚N, Scott M. White, Rachel M. Haymon, D J. Fornari, Michael R. Perfit, Ken C. Macdonald

Faculty Publications

Combined analyses of volcanic features in DSL-120 sonar data and Argo I images along the ridge crest of the East Pacific Rise, 9_090–540N reveal a consistent decrease in inferred lava effusion rate toward the ends of third-order segments. The correlation of tectonic segmentation and volcanic style suggests that third-order segmentation corresponds to the volcanic segmentation of the ridge. Along-axis changes in volcanic structures (from collapse troughs to basaltic lava domes) and lava morphology (from sheet to pillow flows) coincide with the boundaries of morphologically defined third order tectonic segments of the ridge crest visible in shipboard multibeam bathymetry. Pillow lava …

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Electronic Transport Through A Nuclear-Spin-Polarization-Induced Quantum Wire, Yuriy V. Pershin Dr, S. N. Shevchenko, I. D. Vagner, P. Wyder

Faculty Publications

Electron transport in a low-dimensional structure—the nuclear-spin-polarization-induced quantum wire is theoretically studied. In the proposed system the local nuclear-spin polarization creates the effective hyperfine field that confines the electrons with the spins opposite to the hyperfine field to the regions of maximal nuclear-spin polarization. The influence of the nuclear-spin relaxation and diffusion on the electron energy spectrum and on the conductance of the quantum wire is calculated and the experimental feasibility is discussed.

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Volcanic Eruptions On Mid-Ocean Ridges: New Evidence From The Superfast Spreading East Pacific Rise, 17˚-19˚S, John Sinton, Eric Bergmanis, Ken Rubin, Rodey Batiza, Tracy K P Gregg, Karl Gronvold, Ken C. Macdonald, Scott M. White

Faculty Publications

Side-scan sonar, submersible observations and sampling of lava flows from the East Pacific Rise, 17_–19_S constrain the character and variability of submarine volcanic eruptions along mid-ocean ridges. Nine separate lava sequences were mapped using relative age and lithological contrasts among recovered samples. Axial lengths activated during eruptive episodes range from _1 to >18 km; individual flow field areas vary from <1 to >19 km2. Estimated erupted volumes range from <1 to >200 _ 106 m3. The largest unit is the chemically uniform Animal Farm lava near 18_370S. The youngest lava is the Aldo-Kihi flow field, 17_240–340S, probably erupted in the early 1990s from a …

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Geochemistry Of Atmospheric Aerosols Generated From Lava-Seawater Interactions, Francis J. Sansone, Claudia R. Benitez-Nelson, Joseph A. Resing, Eric H. Decarlo, Sue M. Vink, Jacqueline A. Heath, Barry J. Huebert

Faculty Publications

[1] Trace elements were measured in the aerosol plume produced by lava‐seawater interactions along the shoreline of Kilauea volcano, Hawaii. Plume concentrations were normalized relative to Hawaiian basalt composition and showed a linear log‐log co‐variation with their emanation coefficient (an indicator of element volatility). Normalized aerosol concentrations also consistently covaried with corresponding normalized concentrations in dilute fumarolic gas from Kilauea volcano and fumarolic gas condensates from Kudryavy and Merapi volcanoes, despite different mechanisms of element volatilization. Conservatively estimated regional ocean deposition rates of Cu, Cd, Ni, Pb, Mn, Zn, Fe and P were >50 times background rates. Thus, upper ocean …

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De Haas-Van Alphen Oscillations In The Quasi-Two-Dimensional Organic Conductor Κ-(Et)2cu(Ncs)2: The Magnetic Breakdown Approach, V. M. Gvozdikov, Yuriy V. Pershin Dr, E. Steep, A. G. M. Jansen, P. Wyder

Faculty Publications

We present both experimental data and an analytic theory for the de Haas–van Alphen ~dHvA! effect in the two-dimensional organic single-crystal conductor k -(ET)2Cu(NCS)2. We show that the magnetization oscillation pattern and the fast Fourier transform (FFT) spectrum of our measurements are well described theoretically within the coherent magnetic breakdown (MB) model for a two-dimensional Fermi surface consisting of two open sheets and closed pockets connected by magnetic breakdown centers. The spectrum of Landau quantized energy levels changes substantially due to the MB. Landau bands develop whose bandwidth and relative distance between them oscillate in inverse magnetic field. These oscillations …

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Anomalous Conductance Distribution In Quasi-One-Dimensional Gold Wires: Possible Violation Of The One-Parameter Scaling Hypothesis, Pritiraj Mohanty, Richard A. Webb

Faculty Publications

We report measurements of conductance distribution in a set of quasi-one-dimensional gold wires. The distribution includes the second cumulant or the variance which describes the universal conductance fluctuations, and the third cumulant which denotes the leading deviation. We have observed an asymmetric contribution—or, a nonvanishing third cumulant—contrary to the expectation for quasi-one-dimensional systems in the noninteracting theories in the one-parameter scaling framework, which include the perturbative diagrammatic calculations and the random matrix theory.

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A Post-Amadori Inhibitor Pyridoxamine Also Inhibits Chemical Modification Of Proteins By Scavenging Carbonyl Intermediates Of Carbohydrate And Lipid Degradation, Paul A. Voziyan, Thomas O. Metz, John W. Baynes, Billy G. Hudson

Faculty Publications

Reactive carbonyl compounds are formed during autoxidation of carbohydrates and peroxidation of lipids. These compounds are intermediates in the formation of advanced glycation end products (AGE) and advanced lipoxidation end products (ALE) in tissue proteins during aging and in chronic disease. We studied the reaction of carbonyl compounds glyoxal (GO) and glycolaldehyde (GLA) with pyridoxamine (PM), a potent post-Amadori inhibitor of AGE formation in vitro and of development of renal and retinal pathology in diabetic animals. PM reacted rapidly with GO and GLA in neutral, aqueous buffer, forming a Schiff base intermediate that cyclized to a hemiaminal adduct by intramolecular …

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Role Of A Phase: Change Moho In Stabilization And Preservation Of The Southern Uralide Orogen, Russia, Camelia C. Diaconescu, James H. Knapp

Faculty Publications

Geophysical (URSEIS experiment) and geological data from the Southern Uralides of central Russia provide the basis for a geodynamic model involving eclogitization of the Uralian crustal root in Late Triassic to Early Jurassic time as a mechanism for stabilization and preservation of this Paleozoic orogen. The crustal structure of the orogen implies eastward subduction of the East European continental crust, and balanced restoration implies a significant volume of crust (comprised of ~70% European crust, and ~30% accreted terranes) was carried to sub-Moho depths of up to 70 km. The lack of a clearly defined near-vertical incidence reflection Moho corroborated by …

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Crustal Fissuring On The Crest Of The Southern East Pacific Rise At 17˚15'-40'S, Dawn J. Wright, Rachel M. Haymon, Scott M. White, Ken C. Macdonald

Faculty Publications

Fissure densities and widths have been mapped along the axial zone of the superfast spreading southern East Pacific Rise (EPR) at 17_150–400S with the near-bottom DSL-120 and Argo II imaging systems. We observe that the youngest lava flows (on a relative age scale) are sparsely fissured and that there is a cumulative increase in fissure abundance with time that produces a strong positive correlation between fissure density and relative age of lava flows. Average fissure widths were used to estimate fissure depths. In the 17_150–400S area, calculated fissure depths are estimated to extend below the seismic layer 2A/2B boundary, and …

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Full-Text Articles in Physical Sciences and Mathematics

Distributions Of Nobel Metal Pd And Pt In Mesoporous Silica, J. Arbiol, A. Cabot, J. R. Morante, Fanglin Chen, Meilin Liu

Faculty Publications

Volcanic Mound Fields On The East Pacific Rise, 16˚-19˚S: Low Effusion Rate Eruptions At Overlapping Spreading Centers For The Past 1 Myr, Scott M. White, Ken C. Macdonald, John Sinton

Faculty Publications

Seismic Experiments Target Earthquake-Prone Region In Romania, F Hauser, C Prodehl, M Landes, A Bala, V Raileanu, J Bribach, James H. Knapp, Camelia C. Diaconescu, C Dinu, V Mocanu, W Fielitz, S Harder, G. Randy Keller, E Hegedues, R A. Stephenson

Faculty Publications

An Extension Of Elton's L(1)(N) Theorem To Complex Banach Spaces, S J. Dilworth, Joseph P. Patterson

Faculty Publications

Correlation Between Volcanic And Tectonic Segmentation Of Fast-Spreading Ridges: Evidence From Volcanic Structures And Lava Flow Morphology On The East Pacific Rise At 9˚-10˚N, Scott M. White, Rachel M. Haymon, D J. Fornari, Michael R. Perfit, Ken C. Macdonald

Faculty Publications

Electronic Transport Through A Nuclear-Spin-Polarization-Induced Quantum Wire, Yuriy V. Pershin Dr, S. N. Shevchenko, I. D. Vagner, P. Wyder

Faculty Publications

Volcanic Eruptions On Mid-Ocean Ridges: New Evidence From The Superfast Spreading East Pacific Rise, 17˚-19˚S, John Sinton, Eric Bergmanis, Ken Rubin, Rodey Batiza, Tracy K P Gregg, Karl Gronvold, Ken C. Macdonald, Scott M. White

Faculty Publications

Geochemistry Of Atmospheric Aerosols Generated From Lava-Seawater Interactions, Francis J. Sansone, Claudia R. Benitez-Nelson, Joseph A. Resing, Eric H. Decarlo, Sue M. Vink, Jacqueline A. Heath, Barry J. Huebert

Faculty Publications

De Haas-Van Alphen Oscillations In The Quasi-Two-Dimensional Organic Conductor Κ-(Et)2cu(Ncs)2: The Magnetic Breakdown Approach, V. M. Gvozdikov, Yuriy V. Pershin Dr, E. Steep, A. G. M. Jansen, P. Wyder

Faculty Publications

Anomalous Conductance Distribution In Quasi-One-Dimensional Gold Wires: Possible Violation Of The One-Parameter Scaling Hypothesis, Pritiraj Mohanty, Richard A. Webb

Faculty Publications

A Post-Amadori Inhibitor Pyridoxamine Also Inhibits Chemical Modification Of Proteins By Scavenging Carbonyl Intermediates Of Carbohydrate And Lipid Degradation, Paul A. Voziyan, Thomas O. Metz, John W. Baynes, Billy G. Hudson

Faculty Publications

Role Of A Phase: Change Moho In Stabilization And Preservation Of The Southern Uralide Orogen, Russia, Camelia C. Diaconescu, James H. Knapp

Faculty Publications

Crustal Fissuring On The Crest Of The Southern East Pacific Rise At 17˚15'-40'S, Dawn J. Wright, Rachel M. Haymon, Scott M. White, Ken C. Macdonald

Faculty Publications