ESR Endangered Species Research Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout JournalEditorsSpecials 32:533-550 (2017) - DOI: https://doi.org/10.3354/esr00834 Spatial distribution and dive behavior of Gulf Mexico Bryde’s whales: potential risk vessel strikes fisheries interactions Melissa S. Soldevilla1,*, John A. Hildebrand2, Kaitlin E. Frasier2, Laura Aichinger Dias1,3, Anthony Martinez1, Keith D. Mullin4, Patricia...

We present a Molecular Dynamics (MD) study based on Density Functional Theory (DFT) calculations for H(2) interacting with Pd-Cu(111) surface alloy low Pd coverages, Θ(Pd). Our results show, in line recent experimental data, that single isolated atoms evaporated Cu(111) significantly increase the reactivity of otherwise inert pure Cu surface. On top substitutional alloy, activation energy barrier dissociation is smaller than lowest one found by factor two: 0.25 eV vs. 0.46 eV. Also agreement...

Normal incidence scattering of hydrogen atoms off a H-covered tungsten W(110) surface is simulated via quasiclassical trajectories. A density functional theory (DFT) based multiadsorbate potential developed to model wide range coverages, θ = 0.25–1 monolayer (ML), reproducing the arrangements observed at low temperature. The competition between hot-atom (HA) and Eley–Rideal (ER) abstraction mechanisms studied for collision energies projectile atom in Ep 0.1–5.0 eV (Ep 0.1–2.0 eV) 0.25 ML (θ...

Chemisorption of H and H2 on clean W(100) W(110) surfaces is investigated from extensive density functional theory (DFT) calculations within the generalized gradient approximation (GGA). We obtain properties [e.g., well-known reconstructed structure below 200 K] as well adsorption energies geometries atoms chemisorbed both faces W in very good agreement with available experimental data. From our DFT-GGA results, we build accurate six-dimensional potential energy (PESs) which are used to...

Density functional theory was used to investigate the reaction pathways for HSCH(3) adsorption on Au(111) at low coverage. A molecular adsorbed state found with S atom bond Top sites (E approximately -0.38 eV) and is nonactivated. The H-SCH(3) dissociation process energetically less favorable becomes slightly exothermic only when surface relaxation considered (DeltaE -0.2 eV). All present a sizable activation energy barrier, lowest being 0.52 eV (0.41 taking into account slab relaxation). In...

ESR Endangered Species Research Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout JournalEditorsSpecials 33:119-125 (2017) - DOI: https://doi.org/10.3354/esr00770 Exposure of cetaceans petroleum products following Deepwater Horizon oil spill in Gulf Mexico Laura Aichinger Dias1,2,*, Jenny Litz2, Lance Garrison2, Anthony Martinez2, Kevin Barry3, Todd Speakman4,5 1Cooperative Institute for Marine and Atmospheric Studies...

The role of spin non-adiabatic effects in the reactivity O2 on metal surfaces has been a matter debate for several years. By means density functional theory with semi-local exchange-correlation functional, and classical dynamics calculations, we show that recently observed activated character adsorption Cu(111) CuML/Ru(0001), as well delicate interplay between dissociative non-dissociative sticking at different surface temperatures, can be explained by assuming an adiabatic evolution...

The energy loss of proton beams in water vapor is analyzed with a full quantum-mechanical treatment, the distorted-wave model. This model takes into account distortion effects due to long-range Coulomb potential. Projectile energies from 10 keV up 1 MeV are considered. Mean stopping power and equilibrium charge-state fractions calculated compared experimental data. validity Bragg's additivity rule investigated.

This study compares the fundamental spray characteristics, such as penetration depth, droplet diameter, velocity, and volume flux of, biodiesel diesel well their blends. Liquid jet is injected into an air crossflow with a speed of . A series experimental tests covering Weber numbers from 29–82, momentum ratios 10–133, are conducted using shadowgraph method phase Doppler particle analyzer. The images processed to find depth investigate different regimes breakup. analyzer used capture size...

The generalized continuum distorted wave-eikonal initial state (CDW-EIS II) approximation is employed to study differential cross sections (DCS) for single electron capture in H+ + He collisions at intermediate and high energies. Present results are compared with theoretical calculations obtained using the previous CDW-EIS formulation order show importance of description bound target states entrance exit channels, respectively. Both DCS also shown together other experimental data.

The authors report the growth of 6-, 9-, and 12-layer InAs∕InP quantum-dash-in-a-well (DWELL) laser structures using gas source molecular beam epitaxy. Broad area performance has been investigated as a function number layers. highest modal gain at 48cm−1 is achieved for an optimized nine-DWELL layer structure. effect stacking p-type doping on characteristic temperature also reported. Nine-DWELL single mode ridge waveguide lasers showed high slope efficiency (0.2W∕A per facet) output power...

We employ the independent-event model to study transfer-ionization (TI) process in H+, He2+ + He collisions. consider both ionization-capture and capture-ionization paths. The single-particle probabilities for all channels are calculated with continuum distorted wave eikonal initial state model. With TI we calculate doubly differential total cross sections which compared available experimental data. Our present results better agreement experiments than calculations using independent-electron...

A generalization of the continuum distorted wave eikonal initial state (CDW-EIS) approximation, for description single-electron capture in ion–atom collisions involving multielectronic targets is presented. This approximation developed within framework independent electron model taking particular care representation bound and target states. Total cross sections from K-shell He, Ne Ar noble gases by impact bare ions are calculated. Present results compared to previous CDW-EIS ones experimental data.

Dynamics of the Eley-Rideal (ER) abstraction H2 from W(110) is analyzed by means quasi-classical trajectory calculations. Simulations are based on two different molecule-surface potential energy surfaces (PES) constructed Density Functional Theory results. One PES obtained fitting, using a Flexible Periodic London-Eyring-Polanyi-Sato (FPLEPS) functional form, and other interpolation through corrugation reducing procedure (CRP). Then, present study allows us to elucidate ER dynamics...

Arbuscular mycorrhizal (AM) fungal community associated with pecan (Caryaillinoinensis) roots and rhizospheric soils was assessed by spore isolation morphological characterisation pyrosequencing of AM molecular markers. The growing in the field, always more diverse than that containers. This not observed when richness studied, suggesting soil disturbance a reduction host plant leads to less equitable distribution species, contrast natural soils. chosen primers (AMV4.5F/AMDGR) for showed high...

The continuum-distorted-wave--eikonal-initial-state model is applied to the calculation of charged charge-state electronic stopping powers. contributions from electron capture, excitation, and ionization are evaluated for p\ifmmode\bar\else\textasciimacron\fi{}, ${\mathrm{H}}^{+}$, ${\mathrm{He}}^{2+}$, ${\mathrm{Li}}^{3+}$ projectiles impinging on H targets at energies 10--1000 keV/amu. With neutral power obtained first Born approximation, fractions total mean powers ${\mathrm{H}}^{+}$...

The dissociative adsorption of molecular hydrogen on PdxRu1−x/Ru(0001) (0 ≤ x 1) has been investigated by means He atom scattering, Density Functional Theory and quasi-classical trajectory calculations. Regardless their surroundings, Pd atoms in the alloy are always less reactive than Ru ones. However, reactivity is enhanced presence nearest neighbor atoms. This environment-dependent provides a sound explanation for striking step-like dependence initial sticking probability as function...

Double electron capture by fast bare ions in helium is studied the framework of Four-Body Continuum Distorted Wave theory. It shown that experimental data well reproduced when theoretical total cross-section include both contributions from ground state and first singly excited states. In addition, cross-sections for production doubly states are also calculated. Present results call additional at higher impact energies than presently available.

The dissociation of H2 on Ti-covered Al surfaces is relevant to the rehydrogenation and dehydrogenation NaAlH4 hydrogen storage material. energetically most stable structure for a 1/2 monolayer Ti deposited Al(100) surface has atoms in second layer with c(2 × 2) structure, as been confirmed by both low-energy electron diffraction ion scattering experiments density functional theory studies. In this work, we investigate dynamics slab model Ti/Al(100) surface. Two six-dimensional potential...

The newly recognized Rice’s whale Balaenoptera ricei is among the most endangered large species in world and primarily occupies a region near continental shelf break northeastern Gulf of Mexico (GoMex). We analyzed visual line-transect survey data collected throughout northern GoMex from 2003-2019 developed spatially explicit density maps using surface modeling approach to examine relationships between bathymetric oceanographic features. identified water depth, chl concentration, bottom...