bluuebunny/crossref_metadata_2025 huggingface dataset:
Challenges of anticipating the 2011 Tohoku earthquake and tsunami using coastal geology
Authors: Sawai Yuki , Namegaya Yuichi , Okamura Yukinobu , Satake Kenji , Shishikura Masanobu
Published: October 2012

Can the magnitude of a giant earthquake be estimated from paleoseismological data alone? Attempts to estimate the size of the Jogan earthquake of AD 869, whose tsunami affected much of the same coast as the 2011 Tohoku tsunami, offers an excellent opportunity to address this question, which is fundamental to assessing earthquake and tsunami hazards at subduction zones. Between 2004 and 2010, examining stratigraphy at 399 locations beneath paddy fields along 180 km of coast mainly south of Sendai, we learned that a tsunami deposit associated with the AD 869 Jogan earthquake had run inland at least 1.5 km across multiple coastal lowlands, and that one of the lowlands had subsided during the Jogan earthquake and an earlier earthquake as well. Radiocarbon ages just below/above sand deposits left by the pre‐Jogan tsunamis suggested recurrence intervals in the range of 500 to 800 years. Modeling inundation and subsidence, we estimated size of the Jogan earthquake as moment magnitude 8.4 or larger and a fault rupture area 200 km long. We did not consider a longer rupture, like the one in 2011, because coastal landform and absence of a volcanic ash layer make any Jogan layer difficult to identify along the Sanriku coast. Still, Sendai tsunami geology might have reduced casualties by improving evacuation maps and informing public‐awareness campaigns.
Emission ratio of carbonaceous aerosols observed near crop residual burning sources in a rural area of the Yangtze River Delta Region, China
Authors: Pan X. L. , Kanaya Y. , Wang Z. F. , Taketani F. , Tanimoto H. , Irie H. , Takashima H. , Inomata S.
Published: October 2012

Intensive open crop residue burning (OCRB) has a great impact on regional air quality and climate. A field observation campaign in a rural area of the Yangtze River Delta Region (YRDR) was performed during the harvest season, and Elemental carbon (ECa), organic carbon (OC), black carbon (BCe), carbon monoxide (CO), carbon dioxide (CO2) and PM2.5mass were concurrently measured. During the observation period, urban pollution and OCRB‐impact episodes were classified. The emission ratio of ECamass (defined as the ΔECa/ΔCO ratio) from OCRB was estimated to be 18.2 ± 4.6 ng/m3/ppbv, much higher than that (3.0 ± 0.3 ng/m3/ppbv) of urban pollution from the YRDR. A significant amount of OC was emitted from OCRB with ΔOC/ΔCO ratio of 101.3 ± 41.6 ng/m3/ppbv. The value found in the present study was near the upper limit of OC emission ratios in the literature, implying great impacts from combustion conditions, types of biomass burned and subsequent evolution. Regarding urban pollution episodes, the ΔOC/ΔCO ratio was found to be 23.7 ± 2.4 ng/m3/ppbv, and secondary organics accounted for the major fraction of OC mass. Combustions phases of OCRB were classified according to a modified combustion efficiency (MCE, defined as ΔCO2/(ΔCO + ΔCO2)). Our results support the view that ECatend to be produced in flaming combustions (MCE > 0.95) than in smoldering combustions (MCE < 0.95), whereas OC is emitted preferentially from smoldering combustions. Based on our observed carbonaceous aerosol correlations, we estimate that the ECaand OC emissions from OCRB in East Asia might be underestimated by at least 50%.
Suspended sediment properties and suspended sediment flux estimates in an inundated urban environment during a major flood event
Authors: Brown Richard , Chanson Hubert
Published: October 2012

During a major flood event, the inundation of urban environments leads to some complicated flow motion most often associated with significant sediment fluxes. In the present study, a series of field measurements were conducted in an inundated section of the City of Brisbane (Australia) about the peak of a major flood in January 2011. Some experiments were performed to use ADV backscatter amplitude as a surrogate estimate of the suspended sediment concentration (SSC) during the flood event. The flood water deposit samples were predominantly silty material with a median particle size about 25 μm and they exhibited a non‐Newtonian behavior under rheological testing. In the inundated urban environment during the flood, estimates of suspended sediment concentration presented a general trend with increasing SSC for decreasing water depth. The suspended sediment flux data showed some substantial sediment flux amplitudes consistent with the murky appearance of floodwaters. Altogether the results highlighted the large suspended sediment loads and fluctuations in the inundated urban setting associated possibly with a non‐Newtonian behavior. During the receding flood, some unusual long‐period oscillations were observed (periods about 18 min), although the cause of these oscillations remains unknown. The field deployment was conducted in challenging conditions highlighting a number of practical issues during a natural disaster.
Genetics and Hearing Loss
Authors: Schaefer G. Bradley
Published: October 2012

The primary goal of infant hearing screening is, of course, the improved outcome of speech and language in those identified early. There is, however, another major advantage in the early detection of hearing loss. Hearing loss identified by newborn screening can prompt an early investigation into the etiology of the loss. Most cases of hearing loss detected by newborn screening have a genetic etiology. A genetics evaluation can provide the family and providers with several critical pieces of information. For many families, simply knowing the “why” is an important question. Identifying an etiology can also answer questions about recurrence risks for the immediate and extended family. In addition, many of the causes of childhood hearing loss have associated medical conditions, some of which can be medically serious. Knowledge of these risk factors can lead to interventions that prevent morbidity and mortality. All health care providers who work with children with a hearing loss should be aware of the details of a genetic evaluation. They should be prepared to share with the family information regarding the process, the diagnostic yield, and the risks and benefits of such an evaluation.
The Basics of Velopharyngeal Function: A Brief Review for the Practicing Clinician
Authors: Jones David L.
Published: October 2012

In this article, I will provide a basic overview of the normal anatomy and physiology of velopharyngeal function. I will address topics such as the gross anatomy of the velopharyngeal mechanism, identification of the anatomy and function of the velopharyngeal musculature, and patterns of velopharyngeal closure that occur. I will also summarize the role of the velopharyngeal mechanism as it relates to aero-acoustic aspects of speech. Although the focus of this article is normal anatomy, I do include references to abnormal anatomy (e.g. cleft palate). I will include key points to an oral mechanism examination as it pertains to velopharyngeal function.
Key Terms and Concepts Associated With Genetic Analysis Techniques
Authors: Collins Dana R.
Published: October 2012

In order to provide the best care for clients, speech language pathologists and audiologists working with other health care professionals need at least a basic understanding of genetic terms and concepts associated with current genetic analysis techniques. We provide a brief review of some of those key terms and concepts, as well as descriptions of common genetic tests. Along with the references provided in the text, we suggest additional sources of information for the reader.
Viscous heating in large-amplitude oscillatory shear flow
Authors: Giacomin A. J. , Bird R. B. , Aumnate C. , Mertz A. M. , Schmalzer A. M. , Mix A. W.
Published: October 2012

When measuring rheological properties in oscillatory shear flow, one worries about experimental error due to the temperature rise in the sample that is caused by viscous heating. For polymeric liquids, for example, this temperature rise causes the measured values of the components of the complex viscosity to be systematically low. For such linear viscoelastic property measurements, we use an analytical solution by Ding et al. [J. Non-Newtonian Fluid Mech. 86, 359 (1999)10.1016/S0377-0257(99)00004-X] to estimate the temperature rise. However, for large-amplitude oscillatory shear flow, no such analytical solution is available. Here we derive an analytical solution for the temperature rise in a corotational Maxwell fluid (a model with just two parameters: η0 and λ) subject to large-amplitude oscillatory shear flow. This result can then be generalized to a superposition of corotational Maxwell models for a quantitative estimate of the temperature rise. We chose the corotational Maxwell model because, when generalized for multiple relaxation times, it gives an accurate prediction for molten plastics in large-amplitude oscillatory shear flow. We identify three relevant pairs of thermal boundary conditions: (i) both plates isothermal, (ii) with heat loss by convection from both plates, and (iii) one plate isothermal, the other with heat loss by convection. We find that the time-averaged viscous heating increases as an even power series of the dimensionless shear rate amplitude (Weissenberg number), and that it decreases with the dimensionless imposed frequency (Deborah number). We distinguish between the dimensionless time-averaged temperature rise, $\bar \Theta $Θ¯, and the oscillating part, $\tilde \Theta $Θ̃, where $\Theta \equiv \bar \Theta + \tilde \Theta $Θ≡Θ¯+Θ̃. We solve analytically for the $\bar \Theta $Θ¯ profile through the sample thickness for all three pairs of thermal boundary conditions. For the worst case, two adiabatic walls, we derive an expression for the oscillating part of the temperature rise, $\tilde \Theta $Θ̃. We find this $\tilde \Theta $Θ̃ to be a Fourier series of even harmonics whose contribution to the temperature rise can be as important as $\bar \Theta $Θ¯. If both plates are adiabatic, then the sample temperature rises without bound. Otherwise, it does not.
Thin film growth by deposition of randomly shaped clusters
Authors: Ebrahiminejad Zh. , Masoudi S. F. , Dariani R. S. , Jahromi S. S.
Published: October 2012

We have investigated the growth of a porous thin surface film by deposition of randomly shaped clusters with different sizes over an initially flat linear substrate in (1 + 1) dimensions. In analogy with the ballistic deposition process, our approach results in aggregation of clusters with a porous bulk and a rough surface that obeys the Family-Vicsek dynamic scaling. The scaling exponents are calculated and found to agree with the ballistic deposition model. Moreover, the bulk porosity and its dependence on time and cluster size are also investigated. We have also studied the influence of the cluster size on the scaling exponents and the stationary porosity.
Statistical spatio-temporal properties of the Laser MegaJoule speckle
Authors: Le Cain A. , Riazuelo G. , Sajer J. M.
Published: October 2012

This paper investigates a statistical model to describe the spatial and temporal properties of hot spots generated by the superimposition of multiple laser beams. In the context of the Laser MégaJoule design, we introduce the formula for contrasts, trajectories and velocities of the speckle pattern. Single bundle of four beams, two-cones and three-cones configurations are considered. Statistical properties of the speckle in the zone where all the beams overlap are studied with different configurations of polarizations. These properties are shown to be very different from the case of one single bundle of four beams. The configuration of polarization has only a slight effect in the two-cones or three cones configuration. Indeed, the impact of the double polarization smoothing is reduced in the area in which all the beams overlap, while it is much more significant when they split. Moreover, the size of the hot-spots decreases as the number of laser beams increases, but we show that their velocity decreases. As a matter of fact, the maximal velocity of hot spots is found to be only about 10−5 of the velocity of light and the integrated contrast is about 15% when the beams overlap.
Shape analysis using fractal dimension: A curvature based approach
Authors: Backes André R. , Florindo João B. , Bruno Odemir M.
Published: October 2012

The present work shows a novel fractal dimension method for shape analysis. The proposed technique extracts descriptors from a shape by applying a multi-scale approach to the calculus of the fractal dimension. The fractal dimension is estimated by applying the curvature scale-space technique to the original shape. By applying a multi-scale transform to the calculus, we obtain a set of descriptors which is capable of describing the shape under investigation with high precision. We validate the computed descriptors in a classification process. The results demonstrate that the novel technique provides highly reliable descriptors, confirming the efficiency of the proposed method.
Second virial coefficients of H2 and its isotopologues from a six-dimensional potential
Authors: Garberoglio Giovanni , Jankowski Piotr , Szalewicz Krzysztof , Harvey Allan H.
Published: October 2012

We employ path-integral Monte Carlo techniques to compute the second virial coefficient as a function of temperature for molecular hydrogen (H2), deuterium (D2), and tritium (T2), along with the mixed isotopologues HD, HT, and DT. The calculations utilize a new six-dimensional (6D) potential, which is derived by combining our previous high-quality ground-state 4D potential for the H2 dimer with the 6D potential of Hinde. This new 6D potential is reduced to a set of 4D potentials by fixing the intramolecular coordinates at their expectation values for each temperature and isotopic combination. The results for H2 are in good agreement with experimental data; the effect of the temperature dependence of the average bond length is only significant above approximately 1000 K. For D2 and HD, the available experimental data are much more limited; our results agree with the data and provide reliable values at temperatures where no experimental data exist. For the species containing tritium, our results provide the only data available.
High-velocity estimates and inverse scattering for quantum N-body systems with Stark effect
Authors: Valencia Gerardo Daniel , Weder Ricardo
Published: October 2012

In an N–body quantum system with a constant electric field, by inverse scattering, we uniquely reconstruct pair potentials, belonging to the optimal class of short-range potentials and long-range potentials, from the high-velocity limit of the Dollard scattering operator. We give a reconstruction formula with an error term.
Attractiveness of periodic orbits in parametrically forced systems with time-increasing friction
Authors: Bartuccelli Michele , Deane Jonathan , Gentile Guido
Published: October 2012

We consider dissipative one-dimensional systems subject to a periodic force. As a model system, particularly suited for numerical analysis, we investigate the driven cubic oscillator in the presence of friction, and study numerically how time-varying friction affects the dynamics. We find that, if the damping coefficient increases in time up to a final constant value, then the basins of attraction of the leading resonances are larger than they would have been if the coefficient had been fixed at that value since the beginning. From a quantitative point of view, the scenario depends both on the final value and the growth rate of the damping coefficient. The relevance of the results for the spin-orbit model is argued and discussed in some detail.
Lagrangian evolution of the invariants of the velocity gradient tensor in a turbulent boundary layer
Authors: Atkinson C. , Chumakov S. , Bermejo-Moreno I. , Soria J.
Published: October 2012

Lagrangian mean evolution of the invariants of the velocity gradient tensor in different regions of a turbulent boundary layer is investigated using data from a direct numerical simulation of a zero pressure gradient turbulent boundary layer. Conditional mean trajectories (CMTs) are calculated for the evolution of invariants based on their mean rate of change, conditioned on their location in the (RA, QA) plane, which determines the focal or non-focal nature of flow at that point. CMTs are calculated over a larger range of gradients than previously reported boundary layer measurements and show a distinct difference in topological evolution depending on the resolution and the range of invariants considered. In the present case, CMTs for strong gradients in all regions of the boundary layer pass around a focus at the origin and asymptote towards the right-hand side of a saddle point located near the right-hand side of the line dividing unstable focal and unstable nodal structures, consistent with viscous diffusion dominated evolution. Closer to the origin, weaker gradients follow an almost periodic clockwise spiraling evolution from stable-focus stretching to unstable-focus contraction, unstable-node saddle/saddle, and stable-node saddle/saddle topology, similar to that observed in homogeneous isotropic turbulence. Mean time-scales associated with the spiraling evolution in terms of inner scales are estimated at 67.9 \documentclass[12pt]{minimal}\begin{document}$\nu /u^2_\tau$\end{document}ν/uτ2 in the viscous layer, 151 \documentclass[12pt]{minimal}\begin{document}$\nu /u^2_\tau$\end{document}ν/uτ2 in the buffer layer, and 658 \documentclass[12pt]{minimal}\begin{document}$\nu /u^2_\tau$\end{document}ν/uτ2 in the log and wake region. Iso-contours of coherent vortices indicate that these structures typically involve stronger gradients beyond that of the spiraling evolution.
Absence of subcritical instabilities and global nonlinear stability for porous ternary diffusive-convective fluid mixtures
Authors: Rionero Salvatore
Published: October 2012

Porous convection in horizontal layers, heated from below and salted from above and below, is studied. In closed forms, conditions necessary and sufficient for the linear stability of the thermal conduction solution—guaranteeing also the global nonlinear L2 −energy stability—are obtained.
A new potential energy surface for OH(A 2Σ+)–Kr: The van der Waals complex and inelastic scattering
Authors: Chadwick H. , Brouard M. , Chang Y.-P. , Eyles C. J. , Perkins T. , Seamons S. A. , Kłos J. , Alexander M. H. , Aoiz F. J.
Published: October 2012

New ab initio studies of the OH(A2Σ+)–Kr system reveal significantly deeper potential energy wells than previously believed, particularly for the linear configuration in which Kr is bound to the oxygen atom side of OH(A2Σ+). In spite of this difference with previous work, bound state calculations based on a new RCCSD(T) potential energy surface yield an energy level structure in reasonable accord with previous studies. However, the new calculations suggest the need for a reassignment of the vibrational levels of the electronically excited complex. Quantum mechanical and quasi-classical trajectory scattering calculations are also performed on the new potential energy surface. New experimental measurements of rotational inelastic scattering cross sections are reported, obtained using Zeeman quantum beat spectroscopy. The values of the rotational energy transfer cross sections measured experimentally are in good agreement with those derived from the dynamical calculations on the new adiabatic potential energy surface.
Explicit isospectral flows associated to the AKNS operator on the unit interval. II
Authors: Amour Laurent
Published: October 2012

Explicit flows associated to any tangent vector fields on any isospectral manifold for the AKNS operator acting in L2 × L2 on the unit interval are written down. The manifolds are of infinite dimension (and infinite codimension). The flows are called isospectral and also are Hamiltonian flows. It is proven that they may be explicitly expressed in terms of regularized determinants of infinite matrix-valued functions with entries depending only on the spectral data at the starting point of the flow. The tangent vector fields are decomposed as ∑ξkTk where ξ ∈ ℓ2 and the Tk ∈ L2 × L2 form a particular basis of the tangent vector spaces of the infinite dimensional manifold. The paper here is a continuation of Amour [“Explicit isospectral flows for the AKNS operator on the unit interval,” Inverse Probl. 25, 095008 (2009)]10.1088/0266-5611/25/9/095008 where, except for a finite number, all the components of the sequence ξ are zero in order to obtain an explicit expression for the isospectral flows. The regularized determinants induce counter-terms allowing for the consideration of finite quantities when the sequences ξ run all over ℓ2.
Volumes of aqueous hydrogen and hydroxide ions at 0 to 200 °C
Authors: Marcus Yizhak
Published: October 2012

The electrostriction of aqueous hydrogen and hydroxide ions at infinite dilution was calculated by the shell-by-shell method over the temperature range 0 to 200 °C. The calculation required an estimate of the ionic radius of these ions, and comparison with data for aqueous lithium, sodium, and fluoride ions provided values for the nominal sizes of the hydrogen and hydroxide ions in solution. From the volumetric standpoint, these sizes are surprisingly smaller than the size of a water molecule.
On the modified constrained Kadomtsev–Petviashvili equations
Authors: Wu Zhiwei
Published: October 2012

Three reduction sub-hierarchies in constrained KP hierarchies are studied. The corresponding matrix integrable systems are presented. Furthermore, Bäcklund transformations, bi-Hamiltonian structures, and τ-functions are formulated.
Martensitic and magnetic transformation in Mn50Ni50−xSnx ferromagnetic shape memory alloys
Authors: Ma L. , Wang S. Q. , Li Y. Z. , Zhen C. M. , Hou D. L. , Wang W. H. , Chen J. L. , Wu G. H.
Published: October 2012

A martensitic transformation (MT) from a body-centered-cubic austenitic phase to a tetragonal martensitic phase has been found in Mn50Ni50−xSnx (0 ≤ x ≤ 11) alloys. The martensitic transformation temperature can be decreased by about 71.6 K by increasing the Sn concentration by 1 at. %. For 9 ≤ x ≤ 11, Mn50Ni50−xSnx ferromagnetic shape memory alloys are obtained. Due to the large magnetization difference (ΔM = 60 emu/g) and small thermal hysteresis (ΔT = 6 K) in the Mn50Ni40Sn10 alloy, a two-way magnetic-field-induced martensitic transformation is observed with dT/dH = 2 K/T.
Conservation laws of surfactant transport equations
Authors: Kallendorf Christina , Cheviakov Alexei F. , Oberlack Martin , Wang Yongqi
Published: October 2012

Equations of the interfacial convection and convection-diffusion describing the transport of surfactants, and more general interfacial balance laws, in the context of a three-dimensional incompressible two-phase flow are considered. Here, the interface is represented implicitly by a zero level set of an appropriate function. All interfacial quantities and operators are extended from the interface to the three-dimensional domain. In both convection and convection-diffusion settings, infinite families of conservation laws that essentially involve surfactant concentration are derived, using the direct construction method. The obtained results are also applicable to the construction of the general balance laws for other excess surface physical quantities. The system of governing equations is subsequently rewritten in a fully conserved form in the three-dimensional domain. The latter is essential for simulations using modern numerical methods.
Atomic structure of closely stacked InAs submonolayer depositions in GaAs
Authors: Niermann T. , Kießling F. , Lehmann M. , Schulze J.-H. , Germann T. D. , Pötschke K. , Strittmatter A. , Pohl U. W.
Published: October 2012

The atomic structure of multiple buried InAs depositions with a nominal thickness below one monolayer, separated by thin GaAs spacer layers, was investigated using Cs-corrected high-resolution transmission electron microscopy. InAs composition maps were obtained with sub-nanometer resolution by local evaluation of the {200}-Fourier coefficients of the lattice images. A strong segregation behavior of the InAs depositions is found, which leads to significant intermixing with the spacer layers. The segregation coefficient R≈0.7 is found to be independent of the spacer thickness, even for thin spacers with a thickness near the segregation length of about 3 monolayers.
Magnetic hardness features and loop shift in nanostructured CuO
Authors: Bianchi A. E. , Stewart S. J. , Zysler R. D. , Punte G.
Published: October 2012

Nanostructures of cupric oxide (CuO) obtained by ball milling show drastic changes in its magnetic behavior that cannot be only associated to a size effect. While sample of average size D = 29 nm presents a magnetic behavior that resembles that of bulk material with a Néel temperature of 195 K, another sample with D = 24 nm displays a departure from the magnetic features typical of bulk CuO and has magnetic hardness characteristics at low temperatures. Both samples show irreversibility above room temperature and shifts in their hysteresis loops along magnetization and field axis when field cooled in a HFC = 50 kOe to 10 K. At this temperature, an apparent exchange bias like field, “HEB”, 0.17 and 1.06 kOe were estimated for 29 and 24 nm CuO samples, respectively. Magnetic behavior differences observed in samples subjected to distinct milling times are explained as due to a proposed model for milled CuO consisting of a multilayer configuration where interfaces comprise uneven structural disorder and oxygen deficiencies, which generate a peculiar antiferromagnetic/ferromagnetic interface configuration.
Experimental investigation of photonic band gap influence on enhancement of Raman-scattering in metal-dielectric colloidal crystals
Authors: Guddala Sriram , Kamanoor Shadak Alee , Chiappini Andrea , Ferrari Maurizio , Desai Narayana Rao
Published: October 2012

A simple chemical technique is implemented to fabricate a metal-dielectric colloidal crystal structure (MDCS) in order to enhance the otherwise weak Raman signals by combining the effects of localized surface plasmon resonance (LSPR) enhancement due to gold nanoparticles, precise field confinement of dielectric and air bands in the periodic dielectric structure and field enhancements at the photonic band gap (PBG) edges. The higher density of electromagnetic modes (DOS) near these band edges is explained as due to the reduced group velocity at the photonic band gap edges. Intense electric field strength due to the excitation of high DOS at the edges of PBG of MDCS and the LSPR excitation through field confinement in the dielectric medium of MDCS are employed to study the Raman-scattering signals of adsorbed benzenethiol (BT) molecule on the MDCS. Large enhancement for the Raman signal in MDCS in comparison to the Raman spectra observed for BT molecule dispersed on sputtered gold film shows the effectiveness of MDCS for the micro-level detection of the analyte.
A mirage study of CdSe colloidal quantum dot films, Urbach tail, and surface states
Authors: Guyot-Sionnest Philippe , Lhuillier Emmanuel , Liu Heng
Published: October 2012

Thermal deflection spectroscopy allows to measure very small absorption and uncovers absorption tails extending well below the bulk bandgap energy for CdSe quantum dots films after ligand exchange by sulfide. In this monodispersed system, the redshift, the broadening, and the absorption tails cannot be solely attributed to electronic coupling between the dots. Instead, mixing of hole states from the quantum dot and surface is proposed to dominate the changes of the interband spectra at the absorption edge.
A theoretical study of SnF2+, SnCl2+, and SnO2+ and their experimental search
Authors: de Lima Batista Ana Paula , de Lima José Carlos Barreto , Franzreb Klaus , Ornellas Fernando R.
Published: October 2012

We present a detailed theoretical study of the stability of the gas-phase diatomic dications SnF2+, SnCl2+, and SnO2+ using ab initio computer calculations. The ground states of SnF2+, SnCl2+, and SnO2+ are thermodynamically stable, respectively, with dissociation energies of 0.45, 0.30, and 0.42 eV. Whereas SnF2+ dissociates into Sn2+ + F, the long range behaviour of the potential energy curves of SnCl2+ and SnO2+ is repulsive and wide barrier heights due to avoided crossing act as a kind of effective dissociation energy. Their equilibrium internuclear distances are 4.855, 5.201, and 4.852 a0, respectively. The double ionisation energies (Te) to form SnF2+, SnCl2+, and SnO2+ from their respective neutral parents are 25.87, 23.71, and 25.97 eV. We combine our theoretical work with the experimental results of a search for these doubly positively charged diatomic molecules in the gas phase. SnO2+ and SnF2+ have been observed for prolonged oxygen (16O−) ion beam sputtering of a tin metal foil and of tin (II) fluoride (SnF2) powder, respectively, for ion flight times of about 10−5 s through a magnetic-sector mass spectrometer. In addition, SnCl2+ has been detected for 16O− ion surface bombardment of stannous (tin (II)) chloride (SnCl2) powder. To our knowledge, SnF2+ is a novel gas-phase molecule, whereas SnCl2+ had been detected previously by electron-impact ionization mass spectrometry, and SnO2+ had been observed before by spark source mass spectrometry as well as by atom probe mass spectrometry. We are not aware of any previous theoretical studies of these molecular systems.
Thermodynamically consistent description of the hydrodynamics of free surfaces covered by insoluble surfactants of high concentration
Authors: Thiele Uwe , Archer Andrew J. , Plapp Mathis
Published: October 2012

In this paper, we propose several models that describe the dynamics of liquid films which are covered by a high concentration layer of insoluble surfactant. First, we briefly review the “classical” hydrodynamic form of the coupled evolution equations for the film height and surfactant concentration that are well established for small concentrations. Then we re-formulate the basic model as a gradient dynamics based on an underlying free energy functional that accounts for wettability and capillarity. Based on this re-formulation in the framework of nonequilibrium thermodynamics, we propose extensions of the basic hydrodynamic model that account for (i) nonlinear equations of state, (ii) surfactant-dependent wettability, (iii) surfactant phase transitions, and (iv) substrate-mediated condensation. In passing, we discuss important differences to most of the models found in the literature.
Ortho–para-H2 conversion by hydrogen exchange: Comparison of theory and experiment
Authors: Lique François , Honvault Pascal , Faure Alexandre
Published: October 2012

We report fully-quantum time-independent calculations of cross sections and rate coefficients for the collisional (de)excitation of H2 by H. Our calculations are based on the H3 global potential energy surface of Mielke et al. [J. Chem. Phys. 116, 4142 (2002)10.1063/1.1432319]. The reactive hydrogen exchange channels are taken into account. We show that the ortho-para and para-ortho conversion of H2 are significant processes at temperatures above ∼300 K and for the last process we provide the first comparison with available experimental rate coefficients between 300 and 444 K. The good agreement between theory and experiment is a new illustration of our detailed understanding of the simplest chemical reaction. The importance of the ortho–para-H2 conversion by hydrogen exchange in astrophysics is discussed.
Evaluation of physiologic complexity in time series using generalized sample entropy and surrogate data analysis
Authors: Eduardo Virgilio Silva Luiz , Otavio Murta Luiz
Published: October 2012

Complexity in time series is an intriguing feature of living dynamical systems, with potential use for identification of system state. Although various methods have been proposed for measuring physiologic complexity, uncorrelated time series are often assigned high values of complexity, errouneously classifying them as a complex physiological signals. Here, we propose and discuss a method for complex system analysis based on generalized statistical formalism and surrogate time series. Sample entropy (SampEn) was rewritten inspired in Tsallis generalized entropy, as function of q parameter (qSampEn). qSDiff curves were calculated, which consist of differences between original and surrogate series qSampEn. We evaluated qSDiff for 125 real heart rate variability (HRV) dynamics, divided into groups of 70 healthy, 44 congestive heart failure (CHF), and 11 atrial fibrillation (AF) subjects, and for simulated series of stochastic and chaotic process. The evaluations showed that, for nonperiodic signals, qSDiff curves have a maximum point (qSDiffmax) for q≠1. Values of q where the maximum point occurs and where qSDiff is zero were also evaluated. Only qSDiffmax values were capable of distinguish HRV groups (p-values 5.10×10−3, 1.11×10−7, and 5.50×10−7 for healthy vs. CHF, healthy vs. AF, and CHF vs. AF, respectively), consistently with the concept of physiologic complexity, and suggests a potential use for chaotic system analysis.
Influences of lattice vibration and electron transition on thermal emissivity of Nd3+ doped LaMgAl11O19 hexaaluminates for metallic thermal protection system
Authors: Liu Hong-Zhi , Liu Zhan-Guo , Ouyang Jia-Hu , Wang Ya-Ming
Published: October 2012

Normal spectral emissivity of La1−xNdxMgAl11O19 (x = 0.05, 0.10, 0.15, 0.25) ceramics has a maximum value at the Nd3+ content of x = 0.10 in the wavelength range of 3–6 μm. The difference in emissivity at short wavelengths of 3–6 μm is tightly linked to the absorption transitions from 4I9/2 to 4F3/2, 4I15/2, and 4I13/2 and the intensities of radiation transitions from 4F3/2 to 4I11/2 and 4I13/2 of Nd3+ in LaMgAl11O19 ceramics. However, in the wavelength range of 6–14 μm, the emissivity is quite similar for all the samples, which can be ascribed to the stretching vibration of Al-O tetrahedron and Al-O octahedron.
Energy dynamics in a simulation of LAPD turbulence
Authors: Friedman B. , Carter T. A. , Umansky M. V. , Schaffner D. , Dudson B.
Published: October 2012

Energy dynamics calculations in a 3D fluid simulation of drift wave turbulence in the linear Large Plasma Device [W. Gekelman et al., Rev. Sci. Instrum. 62, 2875 (1991)] illuminate processes that drive and dissipate the turbulence. These calculations reveal that a nonlinear instability dominates the injection of energy into the turbulence by overtaking the linear drift wave instability that dominates when fluctuations about the equilibrium are small. The nonlinear instability drives flute-like (k∥=0) density fluctuations using free energy from the background density gradient. Through nonlinear axial wavenumber transfer to k∥≠0 fluctuations, the nonlinear instability accesses the adiabatic response, which provides the requisite energy transfer channel from density to potential fluctuations as well as the phase shift that causes instability. The turbulence characteristics in the simulations agree remarkably well with experiment. When the nonlinear instability is artificially removed from the system through suppressing k∥=0 modes, the turbulence develops a coherent frequency spectrum which is inconsistent with experimental data. This indicates the importance of the nonlinear instability in producing experimentally consistent turbulence.
Plasma-filled diode based on the coaxial gun
Authors: Zherlitsyn A. A. , Kovalchuk B. M. , Pedin N. N.
Published: October 2012

The paper presents the results of studies of a coaxial gun for a plasma-filled electron diode. Effects of the discharge channel diameter and gun current on characteristics of the plasma and pulse generated in the diode were investigated. The electron beam with maximum energy of ≥1 MeV at the current of ≈100 kA was obtained in the experiments with a plasma-filled diode. The energy of ≈5 kJ with the peak power of ≥100 GW dissipated in the diode.
Role of the Ge surface during the end of range dissolution
Authors: Boninelli S. , Impellizzeri G. , Alberti A. , Priolo F. , Cristiano F. , Spinella C.
Published: October 2012

We investigated the structure of end-of-range (EOR) defects in Ge and the role played by the surface during their dissolution caused by annealing. Ge samples were amorphized with Ge+ ions at two different energies (30 and 100 keV) in order to induce, after solid phase epitaxial regrowth, the formation of EOR band at different depths. High resolution x-ray diffraction and transmission electron microscopy showed that the EOR population consists mainly on small defects and few dislocation loops lying on 〈001〉 planes. The deepest EOR defects are more stable during thermal annealing demonstrating the role of the surface during their dissolution.
Generation and storage of 360° domain walls in planar magnetic nanowires
Authors: Geng Liwei D. , Jin Yongmei M.
Published: October 2012

360° domain walls in planar magnetic nanowires are studied by micromagnetic simulations. It is shown that a nanowire loop with a shape-isotropic wall generator at one end and a shape-anisotropic wall stopper at the other end functions like a data storage stack: 360° domain walls are generated and pushed into stack under rotating field before overflow while popped out and annihilated when field rotating direction is inverted until underflow. The stack capacity is determined by total nanowire loop length. This simple nanowire structure can be integrated into magnetic circuits as an operation unit for 360° domain wall generation and storage.
Improved electrical properties of PbZrTiO3/BiFeO3 multilayers with ZnO buffer layer
Authors: Dutta Shankar , Pandey Akhilesh , Yadav I. , Thakur O. P. , Laishram R. , Pal Ramjay , Chatterjee Ratnamala
Published: October 2012

In this study, the effect of ZnO buffer layer on the electrical properties of PbZrTiO3/BiFeO3 (PZT/BFO) multilayers has been reported. For this, PZT/BFO multilayers were spin-coated with and without ZnO buffer layer on platinized silicon wafers. X-ray diffraction results of both the films showed polycrystalline phase pure perovskite structure. Both the films show a dense and homogeneous grain structure. The electric properties of the films were measured. The ZnO buffered multilayer thin film showed ∼3 times improvement in remnant polarization compared to the multilayer thin film with no buffer. The buffered samples were found to have higher dielectric constant (1000 at 100 Hz) compared to that of sample (580 at 100 Hz)) with no buffer. Dielectric constants of both the films were found to be ∼30% tunable at 5 V. The buffered film also showed low leakage current density and higher dielectric breakdown compared to the multilayer thin film without buffer.
Sb concentration dependent structural and resistive properties of polycrystalline Bi-Sb alloys
Authors: Malik K. , Das Diptasikha , Mondal D. , Chattopadhyay D. , Deb A. K. , Bandyopadhyay S. , Banerjee Aritra
Published: October 2012

Polycrystalline Bi1−xSbx alloys have been synthesized over a wide range of antimony concentration (0.08 ≤ x ≤ 0.20) by solid state reaction method. In depth structural analysis using x-ray diffraction (XRD) and temperature dependent resistivity (ρ) measurement of synthesized samples have been performed. XRD data confirmed single phase nature of polycrystalline samples and revealed that complete solid solution is formed between bismuth and antimony. Rietveld refinement technique, utilizing maud software, has been used to perform detailed structural analysis of the samples and lattice parameters of polycrystalline Bi1−xSbx alloys have been estimated. Lattice parameter and unit cell volume decreases monotonically with increasing antimony content. The variation of lattice parameters with antimony concentration depicts a distinct slope change at x = 0.12. Band gap (Eg) has been estimated from the thermal variation of resistivity data, with the 12% Sb content sample showing maximum Eg. It has been observed that with increasing antimony concentration the transition from direct to indirect gap semiconductor is intimately related to the variation of the estimated lattice parameters. Band diagram for the polycrystalline Bi1−xSbx alloy system has also been proposed.
An accurate characterization of interface-state by deep-level transient spectroscopy for Ge metal-insulator-semiconductor capacitors with SiO2/GeO2 bilayer passivation
Authors: Wang Dong , Kojima Shuta , Sakamoto Keita , Yamamoto Keisuke , Nakashima Hiroshi
Published: October 2012

For Ge metal-insulator-semiconductor (MIS) capacitors with a GeO2 interfacial layer, interface-state density (Dit) was accurately characterized using deep-level transient spectroscopy. Elimination of the influence of slow-traps in the gate dielectric film on Dit characterization is described in detail. This was achieved by optimizing the injection pulse and quiescent reverse-bias voltages at each temperature. Dit values of approximately 5 × 1010 cm−2 eV−1 were observed at around mid-gap for both the n- and p-Ge-MIS capacitors with a TiN-gate, for which an asymmetric U-shape energy distribution in Dit was also observed. Furthermore, the effects of post-metallization annealing (PMA) on Dit improvement and slow-trap passivation were also investigated for Al-gated p-Ge-MIS capacitors, on which the defect passivation mechanism in Al-PMA is discussed. A reasonable correspondence was also observed between gate-film quality for Al-gated p-Ge-MIS capacitors and channel mobility in Ge-p-MIS field effect transistors with the gate fabricated by the same process as for p-Ge-MIS capacitors.
Reconstruction of polar magnetic field from single axis tomography of Faraday rotation in plasmas
Authors: Flacco A. , Rax J.-M. , Malka V.
Published: October 2012

An integral back-transform has been developed to retrieve the polar magnetic component in a cylindrically symmetric plasma from a single projection. The formula is derived from parallel forward Radon transform (Abel transform) of a source-free vector field. Two numerical schemes are proposed to solve the backward transform. These schemes have been tested successfully with predefined plasma parameters. The practical application to the analysis of experimental Faraday rotation measurements is also presented, leading to the reconstruction of the transverse profile of the magnetic field.
Continuum resonance induced electromagnetic torque by a rotating plasma response to static resonant magnetic perturbation field
Authors: Liu Yueqiang , Connor J. W. , Cowley S. C. , Ham C. J. , Hastie R. J. , Hender T. C.
Published: October 2012

A numerical study is carried out, based on a simple toroidal tokamak equilibrium, to demonstrate the radial re-distribution of the electromagnetic torque density, as a result of a rotating resistive plasma (linear) response to a static resonant magnetic perturbation field. The computed electromagnetic torque peaks at several radial locations even in the presence of a single rational surface, due to resonances between the rotating response, in the plasma frame, and both Alfvén and sound continuum waves. These peaks tend to merge together to form a rather global torque distribution, when the plasma resistivity is large. The continuum resonance induced net electromagnetic torque remains finite even in the limit of an ideal plasma.
Controlling the current flux in magnetic-barrier induced graphene waveguide
Authors: Villegas Cesar E. P. , Tavares Marcos R. S.
Published: October 2012

We theoretically propose a simple model to control the charge-density flux in graphene waveguides produced by either magnetic or electrostatic barriers. We carefully study the lowest energy guided mode and find unexpected extended states for small reflected angles contributing to flux that might be related to the superposition of surface and bound states. We also show possible manipulation of the charge carrier density, and so of the current flux, by simply changing the magnetization intensity or the waveguide width. Our results indicate how to reassess previous current flux by changing the magnetization parameter only.
Carrier mobility in strained Ge nanowires
Authors: Niquet Yann-Michel , Delerue Christophe
Published: October 2012

We present fully atomistic calculations of the electron and hole mobilities in Ge nanowires with diameter up to 10 nm. We show that the phonon-limited mobility is strongly dependent on the diameter and on the orientation of the nanowire, and is also very responsive to unaxial strains. The similarities and differences with the case of Si nanowires are highlighted. In strained Ge nanowires, the mobility can reach >3000 cm2/V/s for electrons and 12000 cm2/V/s for holes. Ge nanowires are therefore promising nanostructures for ultimate electronic devices.
Short wavelength ion temperature gradient turbulence
Authors: Chowdhury J. , Brunner S. , Ganesh R. , Lapillonne X. , Villard L. , Jenko F.
Published: October 2012

The ion temperature gradient (ITG) mode in the high wavenumber regime (kyρs>1), referred to as short wavelength ion temperature gradient mode (SWITG) is studied using the nonlinear gyrokinetic electromagnetic code GENE. It is shown that, although the SWITG mode may be linearly more unstable than the standard long wavelength (kyρs<1) ITG mode, nonlinearly its contribution to the total thermal ion heat transport is found to be low. We interpret this as resulting from an increased zonal flow shearing effect on the SWITG mode suppression.
Graphene mode-locked femtosecond Yb:KLuW laser
Authors: Ugolotti Elena , Schmidt Andreas , Petrov Valentin , Wan Kim Jun , Yeom Dong-Il , Rotermund Fabian , Bae Sukang , Hee Hong Byung , Agnesi Antonio , Fiebig Christian , Erbert Götz , Mateos Xavier , Aguiló Magdalena , Diaz Francesc , Griebner Uwe
Published: October 2012

Large-area monolayer graphene, synthesized by chemical vapor deposition, was transferred to a 1-in. quartz substrate. The high-quality monolayer graphene has been subject to characterization of the nonlinear properties near 1 μm and was successfully applied as saturable absorber for passive mode-locking of a femtosecond Yb:KLuW laser. The diode-pumped mode-locked Yb:KLuW laser was tunable around 1.04 μm and delivered pulses as short as 160 fs. The maximum output power of 160 mW was demonstrated for 203 fs pulse duration. The mode-locked laser results are comparable to those demonstrated with the same laser gain medium using single-walled carbon nanotubes as saturable absorbers.
Size-dependent radiative decay processes in graphene quantum dots
Authors: Kim Sung , Hee Shin Dong , Oh Kim Chang , Seok Kang Soo , Min Kim Jong , Choi Suk-Ho , Jin Li-Hua , Cho Yong-Hoon , Won Hwang Sung , Sone Cheolsoo
Published: October 2012

Radiative decay processes have been studied in graphene quantum dots (GQDs) by varying their size. The photoluminescence (PL) decay traces are well fitted to a biexponential function with lifetimes of τ1 and τ2, indicating their fast and slow components, respectively. The τ1 is almost constant, irrespective of the average GQD size (da) for two excitation wavelengths of 305 and 356 nm. In contrast, the τ2 decreases as da increases for da ≤ ∼17 nm, but da > ∼17 nm, it increases with increasing da for both the excitation wavelengths, similar to the size-dependent behaviors of the time-integrated PL peak energy. We propose that the τ1 and τ2 originate from size-independent fast band-to-band transition and size-dependent slow transition resulting from the edge-state variation at the periphery of GQDs, respectively.