bluuebunny/crossref_metadata_2025 huggingface dataset:
Ensemble smoothing of land subsidence measurements for reservoir geomechanical characterization
Authors: Baù Domenico , Ferronato Massimiliano , Gambolati Giuseppe , Teatini Pietro , Alzraiee Ayman
Published: July 2014

Geomechanical models are often used to predict the impact on land surface of fluid withdrawal from deep reservoirs, as well as investigating measures for mitigation. The ability to accurately simulate surface displacements, however, is often impaired by limited information on the geomechanical parameters characterizing the geological formations of interest. In this study, we employ an ensemble smoother, a data assimilation algorithm, to provide improved estimates of reservoir parameters through assimilation of measurements of both horizontal and vertical surface displacement into geomechanical model results. The method leverages the demonstrated potential of remote sensing techniques developed in the last decade to provide accurate displacement data for large areas of the land surface.

For evaluation purposes, the methodology is applied to the case of a disk‐shaped reservoir embedded in a homogeneous, isotropic, and linearly elastic half space, subject to a uniform change in fluid pressure. Multiple sources of uncertainty are investigated, including the radius,R, the thickness,h, and the depth,c, of the reservoir; the pore pressure change,Δp; porous medium's vertical uniaxial compressibility,cM, and Poisson's ratio,ν, and the ratio,s, between the compressibilities of the medium during loading and unloading cycles. Results from all simulations show that the ensemble smoother has the capability to effectively reduce the uncertainty associated with those parameters to which the variability and the spatial distribution of land surface displacements are most sensitive, namely,R,c,cM, ands. These analyses demonstrate that the estimation of these parameters values depends on the number of measurements assimilated and the error assigned to the measurement values. Copyright © 2014 John Wiley & Sons, Ltd.
Reducing shadowing losses with femtosecond‐laser‐written deflective optical elements in the bulk of EVA encapsulation
Authors: Kuna Ladislav , Eder Gabriele C. , Leiner Claude , Peharz Gerhard
Published: July 2014

A new approach on decreasing the optical shadowing of the solar cell grid fingers is presented. The approach relies on a local change of the optical properties in the bulk of the photovoltaic module encapsulation material ethylene vinyl acetate (EVA). In particular, scattering and diffractive optical elements are locally generated within the volume of cross‐linked EVA encapsulation material by applying a femtosecond‐laser‐writing process. When these optical elements are located above the metal grid fingers, the optical shadowing of these grid fingers can be decreased. In an experimental proof of concept, the optical performance of this approach is demonstrated. The best results obtained so far indicate a decrease in optical shadowing by 17%. The material characteristics of the volume optics were investigated by applying confocal Raman microscopic characterisation, which indicates that the EVA material partially degraded upon the impact of the laser beam and is partly carbonised. Supplementary optical simulations show that the light deflection is caused by diffraction. However, parasitic absorption substantially deteriorates the optical performance of the deflective volume optics. Copyright © 2014 John Wiley & Sons, Ltd.
Core–Shell Structure of Hierarchical Quasi‐Hollow MoS2 Microspheres Encapsulated Porous Carbon as Stable Anode for Li‐Ion Batteries
Authors: Wan Zhongming , Shao Jie , Yun Jiaojiao , Zheng Huiyuan , Gao Tian , Shen Ming , Qu Qunting , Zheng Honghe
Published: July 2014

Monodisperse sulfonated polystyrene (SPS) microspheres are employed as both the template and carbon source to prepare MoS2 quasi‐hollow microspheres‐encapsulated porous carbon. The synthesis procedure involves the hydrothermal growth of MoS2 ultrathin nanosheets on the surface of SPS microspheres and subsequent annealing to remove SPS core. Incomplete decomposition of SPS during annealing due to the confining effect of MoS2 shells leaves residual porous carbon in the interior. When being evaluated as the anode materials of Li‐ion batteries, the as‐prepared C@MoS2 microspheres exhibit excellent cycling stability (95% of capacity retained after 100 cycles) and high rate behavior (560 mAh g−1 at 5 A g−1).
Complete Sequence of pABTJ2, A Plasmid from Acinetobacter Baumannii MDR-TJ, Carrying Many Phage-Like Elements
Authors: Huang He , Dong Yan , Yang Zhi-Liang , Luo Hao , Zhang Xi , Gao Feng
Published: July 2014

Acinetobacter baumannii is an important opportunistic pathogen in hospital, and the multidrug-resistant isolates of A. baumannii have been increasingly reported in recent years. A number of different mechanisms of resistance have been reported, some of which are associated with plasmid-mediated acquisition of genes. Therefore, studies on plasmids in A. baumannii have been a hot issue lately. We have performed complete genome sequencing of A. baumannii MDR-TJ, which is a multidrug-resistant isolate. Finalizing the remaining large scaffold of the previous assembly, we found a new plasmid pABTJ2, which carries many phage-like elements. The plasmid pABTJ2 is a circular double-stranded DNA molecule, which is 110,967 bp in length. We annotated 125 CDSs from pABTJ2 using IMG ER and ZCURVE_V, accounting for 88.28% of the whole plasmid sequence. Many phage-like elements and a tRNA-coding gene were detected in pABTJ2, which is rarely reported among A. baumannii. The tRNA gene is specific for asparagine codon GTT, which may be a small chromosomal sequence picked up through incorrect excision during plasmid formation. The phage-like elements may have been acquired during the integration process, as the GC content of the region carrying phage-like elements was higher than that of the adjacent regions. The finding of phage-like elements and tRNA-coding gene in pABTJ2 may provide a novel insight into the study of A. baumannii pan-plasmidome.
Amyloid burden, cerebrovascular disease, brain atrophy, and cognition in cognitively impaired patients
Authors: Ye Byoung Seok , Seo Sang Won , Kim Geon Ha , Noh Young , Cho Hanna , Yoon Cindy W. , Kim Hee Jin , Chin Juhee , Jeon Seun , Lee Jong Min , Seong Joon-Kyung , Kim Jae Seung , Lee Jae-Hong , Choe Yearn Seong , Lee Kyung Han , Sohn Young H. , Ewers Michael , Weiner Michael , Na Duk L.
Published: July 2014

Background

We investigated the independent effects of Alzheimer's disease (AD) and cerebrovascular disease (CVD) pathologies on brain structural changes and cognition.

Methods

Amyloid burden (Pittsburgh compound B [PiB] retention ratio), CVD markers (volume of white matter hyperintensities [WMH] and number of lacunae), and structural changes (cortical thickness and hippocampal shape) were measured in 251 cognitively impaired patients. Path analyses were utilized to assess the effects of these markers on cognition.

Results

PiB retention ratio was associated with hippocampal atrophy, which was associated with memory impairment. WMH were associated with frontal thinning, which was associated with executive and memory dysfunctions. PiB retention ratio and lacunae were also associated with memory and executive dysfunction without the mediation of hippocampal or frontal atrophy.

Conclusions

Our results suggest that the impacts of AD and CVD pathologies on cognition are mediated by specific brain regions.
High efficiency tandem mass spectrometry analysis using dual linear ion traps
Authors: Li Linfan , Zhou Xiaoyu , Hager James W. , Ouyang Zheng
Published: July 2014

Dual LIT mass spectrometry for high efficiency MS/MS analysis.
Comparative STM studies of mixed ligand monolayers on gold nanoparticles in air and in 1-phenyloctane
Authors: Ong Quy Khac , Zhao Shun , Reguera Javier , Biscarini Fabio , Stellacci Francesco
Published: July 2014

Scanning tunnelling microscopy (STM) studies have found that stripe-like domains on gold nanoparticles (NPs) have the same characteristic length in air and in 1-phenyloctane.
Theoretical analysis of high-field transport in graphene on a substrate
Authors: Serov Andrey Y. , Ong Zhun-Yong , Fischetti Massimo V. , Pop Eric
Published: July 2014

We investigate transport in graphene supported on various dielectrics (SiO2, BN, Al2O3, and HfO2) through a hydrodynamic model which includes self-heating and thermal coupling to the substrate, scattering with ionized impurities, graphene phonons, and dynamically screened interfacial plasmon-phonon (IPP) modes. We uncover that while low-field transport is largely determined by impurity scattering, high-field transport is defined by scattering with dielectric-induced IPP modes, and a smaller contribution of graphene intrinsic phonons. We also find that lattice heating can lead to negative differential drift velocity (with respect to the electric field), which can be controlled by changing the underlying dielectric thermal properties or thickness. Graphene on BN exhibits the largest high-field drift velocity, while graphene on HfO2 has the lowest one due to strong influence of IPP modes.
A direct method to transform between expansions in the configuration state function and Slater determinant bases
Authors: Olsen Jeppe
Published: July 2014

A novel algorithm is introduced for the transformation of wave functions between the bases of Slater determinants (SD) and configuration state functions (CSF) in the genealogical coupling scheme. By modifying the expansion coefficients as each electron is spin-coupled, rather than performing a single many-electron transformation, the large transformation matrix that plagues previous approaches is avoided and the required number of operations is drastically reduced. As an example of the efficiency of the algorithm, the transformation for a configuration with 30 unpaired electrons and singlet spin is discussed. For this case, the 10 × 106 coefficients in the CSF basis is obtained from the 150 × 106 coefficients in the SD basis in 1 min, which should be compared with the seven years that the previously employed method is estimated to require.
Optimization of confocal laser induced fluorescence in a plasma
Authors: VanDervort R. , Elliott D. , McCarren D. , McKee J. , Soderholm M. , Sears S. , Scime E.
Published: July 2014

Laser Induced Fluorescence (LIF) provides measurements of flow speed, temperature, and density of ions or neutrals in a plasma. Traditionally, a LIF measurement requires two ports on a plasma device; one for laser injection and one for emission collection. Proper alignment of LIF optics is time consuming and sensitive to mechanical vibration. We describe a confocal configuration for LIF that requires a single port and requires no alignment. The measurement location is scanned radially by physically moving the entire optical structure. Confocal LIF measurements are compared to traditional LIF measurements over the same radial range.
The solvent-induced interaction of spherical solutes in associated and non-associated liquids
Authors: Djikaev Yuri S. , Ruckenstein Eli
Published: July 2014

We propose an efficient method for studying the solvent-induced interaction of two solvophobic particles immersed in a liquid solvent. The method is based on the combination of the probabilistic hydrogen bond model with the density functional theory. An analytic expression for the number of hydrogen bonds per water molecule near two spherical hydrophobes is derived as a function of the molecule distance to both hydrophobes, distance between hydrophobes, and their radii. Using this expression, one can construct an approximation for the distribution of fluid (liquid water) molecules in the system which provides a reasonably good (much faster and accurate enough) alternative to a standard iteration procedure. Such an approximate density distribution constitutes an efficient foundation for studying the length-scale and temperature dependence of hydrophobic interactions. The model is applied to the interaction of solvophobic solutes in both associated and non-associated liquids. Of these two cases, the model predictions for the solvent-induced potential of mean force between two solutes in associated liquids are closer to the results of molecular dynamics simulation of hydrophobic interactions in the SPC/E model water. Our results suggest that the hydrogen bonding ability of water molecules may play a major role in hydrophobic phenomena.
Periodic and stochastic thermal modulation of protein folding kinetics
Authors: Platkov Max , Gruebele Martin
Published: July 2014

Chemical reactions are usually observed either by relaxation of a bulk sample after applying a sudden external perturbation, or by intrinsic fluctuations of a few molecules. Here we show that the two ideas can be combined to measure protein folding kinetics, either by periodic thermal modulation, or by creating artificial thermal noise that greatly exceeds natural thermal fluctuations. We study the folding reaction of the enzyme phosphoglycerate kinase driven by periodic temperature waveforms. As the temperature waveform unfolds and refolds the protein, its fluorescence color changes due to FRET (Förster resonant Energy Transfer) of two donor/acceptor fluorophores labeling the protein. We adapt a simple model of periodically driven kinetics that nicely fits the data at all temperatures and driving frequencies: The phase shifts of the periodic donor and acceptor fluorescence signals as a function of driving frequency reveal reaction rates. We also drive the reaction with stochastic temperature waveforms that produce thermal fluctuations much greater than natural fluctuations in the bulk. Such artificial thermal noise allows the recovery of weak underlying signals due to protein folding kinetics. This opens up the possibility for future detection of a stochastic resonance for protein folding subject to noise with controllable amplitude.
Variational mixed quantum/semiclassical simulation of dihalogen guest and rare-gas solid host dynamics
Authors: Cheng Xiaolu , Cina Jeffrey A.
Published: July 2014

A variational mixed quantum-semiclassical theory for the internal nuclear dynamics of a small molecule and the induced small-amplitude coherent motion of a low-temperature host medium is developed, tested, and used to simulate the temporal evolution of nonstationary states of the internal molecular and surrounding medium degrees of freedom. In this theory, termed the Fixed Vibrational Basis/Gaussian Bath (FVB/GB) method, the system is treated fully quantum mechanically while Gaussian wave packets are used for the bath degrees of freedom. An approximate time-dependent wave function of the entire model is obtained instead of just a reduced system density matrix, so the theory enables the analysis of the entangled system and bath dynamics that ensues following initial displacement of the internal-molecular (system) coordinate from its equilibrium position. The norm- and energy-conserving properties of the propagation of our trial wave function are natural consequences of the Dirac-Frenkel-McLachlan variational principle. The variational approach also stabilizes the time evolution in comparison to the same ansatz propagated under a previously employed locally quadratic approximation to the bath potential and system-bath interaction terms in the bath-parameter equations of motion. Dynamics calculations are carried out for molecular iodine in a 2D krypton lattice that reveal both the time-course of vibrational decoherence and the details of host-atom motion accompanying energy dissipation and dephasing. This work sets the stage for the comprehensive simulation of ultrafast time-resolved optical experiments on small molecules in low-temperature solids.
A numerical study of fixed frequency reflectometry measurements of plasma filaments with radial and poloidal velocity components
Authors: Vicente J. , da Silva F. , Heuraux S. , Manso M. E. , Conway G. D. , Silva C.
Published: July 2014

A 2D finite-differences time-domain full-wave code is used to simulate the measurements of plasma filaments with fixed frequency O-mode reflectometry. The plasma is modeled by a linear slab plasma plus a Gaussian perturbation propagating in a direction that can vary from poloidal to radial. The plasma background density gradient is chosen in agreement with the steep edge transport barrier of H-modes in the ASDEX Upgrade (AUG) tokamak. Illustrative results are presented and different types of reflectometry responses are observed depending on filament sizes and propagation directions. The reflectometry signatures obtained here with numerical simulations support previous experimental findings on filament measurements.
Integration of ultrafast scanning calorimetry with micro-Raman spectroscopy for investigation of metastable materials
Authors: Wei Lai , Jiang Jing , Shan Meijuan , Chen Wei , Deng Yu , Xue Gi , Zhou Dongshan
Published: July 2014

A stage-type ultrafast scanning calorimetry (ST-UFSC) with controlled heating and cooling rates up to 105 K s−1 was designed to integrate with microstructural characterization. This enables us to precisely control the evolution of fast transitional states of metastable samples provided by the UFSC platform, and to follow subtle structural changes between intermediate stages. As an example, we collected the Raman spectra of poly(ethylene terephthalate) quenched at different crystallization states obtained by programed rapid cooling and heating processes. Because of the very small sample mass for UFSC measurements, from minimum few nanograms to sub-micrograms, the sample's temperature is very sensitive to the perturbation from the laser illumination of the Raman spectrometer. Real time temperature monitoring and compensation was accompanied during the whole process of in situ spectroscopy. The results showed a good agreement of crystallization kinetics obtained from the Raman spectroscopy and from the calorimetric melting enthalpy, given that the sample temperature is well controlled during spectroscopic measurements and that the heating rate for calorimetry is fast enough to suppress structural reorganization during heating scans. We expect that the ST-UFSC is suitable to be integrated with other micro-analysis techniques to investigate the structure and dynamics of metastable states obtained by fast thermal treatments.
Design of 95 GHz gyrotron based on continuous operation copper solenoid with water cooling
Authors: Borodin Dmitri , Ben-Moshe Roey , Einat Moshe
Published: July 2014

The design work for 2nd harmonic 95 GHz, 50 kW gyrotron based on continuous operation copper solenoid is presented. Thermionic magnetron injection gun specifications were calculated according to the linear trade off equation, and simulated with CST program. Numerical code is used for cavity design using the non-uniform string equation as well as particle motion in the “cold” cavity field. The mode TE02 with low Ohmic losses in the cavity walls was chosen as the operating mode. The Solenoid is designed to induce magnetic field of 1.8 T over a length of 40 mm in the interaction region with homogeneity of ±0.34%. The solenoid has six concentric cylindrical segments (and two correction segments) of copper foil windings separated by water channels for cooling. The predicted temperature in continuous operation is below 93 °C. The parameters of the design together with simulation results of the electromagnetic cavity field, magnetic field, electron trajectories, and thermal analyses are presented.
Stark effect in ensembles of polar (0001) Al0.5Ga0.5N/GaN quantum dots and comparison with semipolar (11−22) ones
Authors: Leroux M. , Brault J. , Kahouli A. , Maghraoui D. , Damilano B. , de Mierry P. , Korytov M. , Kim Je-Hyung , Cho Yong-Hoon
Published: July 2014

This work presents a continuous-wave photoluminescence study of Al0.5Ga0.5N/GaN quantum dots grown by ammonia-assisted molecular beam epitaxy on sapphire, either on the wurtzite polar (0001) or the semipolar (11−22) plane. Due to interface polarization discontinuities, the polar dots are strongly red-shifted by the Stark effect and emit in the visible range. Carrier injection screening of the polarization charges has been studied. A model relying on average dot heights and dot height variances, as measured by transmission electron microscopy, is proposed. It can account for the injection dependent luminescence energies and efficiencies. The electric field discontinuity deduced from the fittings is in good agreement with theoretical expectations for our barrier composition. On the contrary, semipolar quantum dot ensembles always emit above the gap of GaN strained to Al0.5Ga0.5N. Their luminescence linewidth is significantly lower than that of polar ones, and their energy does not shift with injection. Our study then confirms the expected strong decrease of the Stark effect for (11−22) grown (Al,Ga)N/GaN heterostructures.
Biot-Savart helicity versus physical helicity: A topological description of ideal flows
Authors: Sahihi Taliya , Eshraghi Homayoon
Published: July 2014

For an isentropic (thus compressible) flow, fluid trajectories are considered as orbits of a family of one parameter, smooth, orientation-preserving, and nonsingular diffeomorphisms on a compact and smooth-boundary domain in the Euclidian 3-space which necessarily preserve a finite measure, later interpreted as the fluid mass. Under such diffeomorphisms the Biot-Savart helicity of the pushforward of a divergence-free and tangent to the boundary vector field is proved to be conserved and since these circumstances present an isentropic flow, the conservation of the “Biot-Savart helicity” is established for such flows. On the other hand, the well known helicity conservation in ideal flows which here we call it “physical helicity” is found to be an independent constant with respect to the Biot-Savart helicity. The difference between these two helicities reflects some topological features of the domain as well as the velocity and vorticity fields which is discussed and is shown for simply connected domains the two helicities coincide. The energy variation of the vorticity field is shown to be formally the same as for the incompressible flow obtained before. For fluid domains consisting of several disjoint solid tori, at each time, the harmonic knot subspace of smooth vector fields on the fluid domain is found to have two independent base sets with a special type of orthogonality between these two bases by which a topological description of the vortex and velocity fields depending on the helicity difference is achieved since this difference is shown to depend only on the harmonic knot parts of velocity, vorticity, and its Biot-Savart vector field. For an ideal magnetohydrodynamics (MHD) flow three independent constant helicities are reviewed while the helicity of magnetic potential is generalized for non-simply connected domains by inserting a special harmonic knot field in the dynamics of the magnetic potential. It is proved that the harmonic knot part of the vorticity in hydrodynamics and the magnetic field in MHD is presented by constant coefficients (fluxes) when expanded in terms of one of the time dependent base functions.
Micro-slotted whispering gallery mode resonators for optomechanical applications
Authors: Aveline David C. , Strekalov Dmitry V. , Yu Nan
Published: July 2014

We present a study of augmented whispering gallery mode optical resonators that contain one or more narrow slots, through which the optical field exits the resonator's dielectric material and propagates in free space. We developed a theoretical model describing the micro-slotted resonator mode spectrum, and we find the theoretical results of the single-slot case are in close agreement with experimental observations. Furthermore, we examine a double-slot configuration that forms a cantilever-like partition within the circulating high-Q optical modes. The system exhibits high displacement sensitivity that could lead to optomechanical sensing applications.
Wind farm layout optimization using imperialist competitive algorithm
Authors: Kiamehr Koosha , Hannani Siamak Kazemzadeh
Published: July 2014

In this work, the wind farm layout optimization problem is dealt with using a new approach. The aim of wind farm layout optimization is to maximize the output power of a wind farm considering the wake losses. Layout optimization minimizes the wake losses regarding the location of the turbines. Three different wind scenarios with different wind direction angles, wind direction blowing probabilities, and Weibull distribution parameters are assumed. Since, the problem is nonlinear and constrained, imperialist competitive algorithm is used as a modern and powerful algorithm for continuous optimization problems. The optimization outcomes indicate that imperialist competitive algorithm yields promising results.
Non-contact direct measurement of the magnetocaloric effect in thin samples
Authors: Cugini F. , Porcari G. , Solzi M.
Published: July 2014

An experimental setup, based on a non-contact temperature sensor, is proposed to directly measure the magnetocaloric effect of samples few micrometers thick. The measurement of the adiabatic temperature change of foils and ribbons is fundamental to design innovative devices based on magnetocaloric thin materials or micro-structuring bulk samples. The reliability of the proposed setup is demonstrated by comparing the measurements performed on a bulk gadolinium sample with the results obtained by an experimental setup based on a Cernox bare chip thermoresistance and by in-field differential scanning calorimetry. We show that this technique can measure the adiabatic temperature variation on gadolinium sheets as thin as 27 μm. Heat transfer simulations are added to describe the capability of the presented technique.
On the marginal instability threshold condition of the aperiodic ordinary mode
Authors: Schlickeiser R. , Yoon P. H.
Published: July 2014

The purely growing ordinary (O) mode instability has recently received renewed attention owing to its potential applicability to the solar wind plasma. Here, an analytical marginal instability condition is derived for counter-streaming bi-Maxwellian plasma particle distribution functions. The derived marginal instability condition as a function of the temperature anisotropy and plasma beta agrees remarkably well with the numerically determined instability condition. The existence of a new instability domain of the O-mode at small plasma beta values is confirmed with the leading A∝β∥−1-dependence, if the counter-stream parameter Pe exceeds a critical value. At small plasma beta values at large enough counter-stream parameter, the O-mode also operates for temperature anisotropies A = T⊥/T∥ > 1 even larger than unity, as the parallel counter-stream free energy exceeds the perpendicular bi-Maxwellian free energy.
On the mechanism of acceleration behavior of plasma bullet
Authors: Wu S. , Lu X. , Pan Y.
Published: July 2014

Two special experiments are designed to study the mechanism of the acceleration behavior of a plasma bullet when it exits a nozzle. First, a T-shape device is used to simulate the air diffusion when a plasma plume exits the nozzle. It is found that adding just 1% of N2, O2, or air to the main working gas He results in the acceleration of the plasma bullet. Second, materials of different permittivity are added to the left part of the outside of the tube. The experimental results show that the plasma bullet accelerates at the moment when it enters into the right part of the tube where there is no extra material on the outside of the tube. These two experiments confirm that the acceleration behavior of the plasma bullet when it exits the nozzle is due to the air diffusion, hence Penning ionization, and the permittivity change when the bullet exits the nozzle, for example, from a tube with high permittivity to air with low permittivity. Besides, electric field measurements show that the electric field in the bullet head increases when the plasma bullet accelerates. This confirms the electric field driven nature of the plasma bullet propagation.
An analytical model to predict curvature effects of the carbon nanotube on the overall behavior of nanocomposites
Authors: Yang B. J. , Souri H. , Kim Sunghwan , Ryu Seunghwa , Lee H. K.
Published: July 2014

In this study, analytical expressions are introduced to provide a better understanding of carbon nanotubes (CNTs) curvature on the overall behavior of nanocomposites. The curviness of CNT is modeled as the wave geometries, and the transformed physical characteristics are applied to micromechanical framework. Since five independent elastic constants of CNTs are essential to derive the waviness effect, atomistic molecular statics simulations with varying nanotube radii are conducted. Influences of CNT curviness on the effective stiffness of the nanocomposites are analyzed, noting that the curvature effect is significantly influential on the effective stiffness of the nanocomposites, and it may improve or reduce the reinforcing effect depending on the orientation of CNTs. In addition, the predictions are compared with experimental data of the CNT-reinforced nanocomposites to assess the reliability of the proposed method. The developed constitutive model is expected to be used to determine the volume concentration of the reinforcing CNTs and mechanical responses of CNT-reinforced composites under various CNT curvature, radius, and orientation conditions.
Microsphere-chain waveguides: Focusing and transport properties
Authors: Allen Kenneth W. , Darafsheh Arash , Abolmaali Farzaneh , Mojaverian Neda , Limberopoulos Nicholaos I. , Lupu Anatole , Astratov Vasily N.
Published: July 2014

It is shown that the focusing properties of polystyrene microsphere-chain waveguides (MCWs) formed by sufficiently large spheres (D ≥ 20λ, where D is the sphere diameter and λ is the wavelength of light) scale with the sphere diameter as predicted by geometrical optics. However, this scaling behavior does not hold for mesoscale MCWs with D ≤ 10λ resulting in a periodical focusing with gradually reducing beam waists and in extremely small propagation losses. The observed effects are related to properties of nanojet-induced and periodically focused modes in such structures. The results can be used for developing focusing microprobes, laser scalpels, and polarization filters.
Bright emissive core-shell spherical microparticles for shock compression spectroscopy
Authors: Christensen James M. , Banishev Alexandr A. , Dlott Dana D.
Published: July 2014

Experiments were performed to study the response to shock compression of rhodamine 6G (R6G) dye encapsulated in 1.25 μm diameter silica microspheres. When R6G was encapsulated in microspheres, the emission intensity under steady-state irradiation (the brightness) was 3.4 times greater than the same dye in solution (the free dye). At least part of the brightness improvement was caused by an enhanced radiative rate. When the microspheres were embedded in poly-methylmethacrylate subjected to planar shocks in the 3–8.4 GPa range by laser-driven flyer plates, the dye emission redshifted and lost intensity. The dye emission redshift represents an instantaneous response to changes in the local density. In free dye samples, the shock-induced intensity loss had considerably slower rise times and fall times than the redshift. When dye was encapsulated in microspheres, the time dependence of the intensity loss matched the redshift almost exactly over a range of shock pressures and durations. The faster response to shock of dye in silica microspheres was explained by dye photophysics. The microsphere environment decreased the singlet state lifetime, which decreased the rise time, and it also decreased the triplet state lifetime, which decreased the fall time. Since it is much easier and more convenient to make measurements of intensity rather than spectral shift, these microspheres represent a substantial improvement in optical sensors to monitor shock compression of microstructured materials.
A molecular dynamics study of the early-time mechanical heating in shock-loaded octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine-based explosives
Authors: Long Yao , Chen Jun
Published: July 2014

We study the shock-induced hot spot formation mechanism of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine-based explosives by molecular dynamics, compare different kinds of desensitizers and different shock velocities. A set of programs is written to calculate the physical picture of shock loading. Based on the simulations and analyses, the hot spots are found at the interface and are heated by plastic work in three ways: the interface intrinsic dissipation, the pore collapse, and the coating layer deformation. The work/heat transition rate is proved to be increasing with a loading speed.
Modulation of a Josephson current through an Nb/Al-AlOx/Nb Josephson junction by a parallel magnetic field and a perpendicular magnetic field
Authors: Watanabe Norimichi , Abe Susumu , Nakayama Akiyoshi
Published: July 2014

We have investigated the perpendicular magnetic field dependence of Josephson current through Nb/Al-AlOx/Nb junctions by applying a magnetic field in a direction perpendicular to the plane of the junction. We found hysteresis in the modulation characteristics of the Josephson current when a strong perpendicular magnetic field was applied to the Josephson junction. We have now measured the three-dimensional magnetic field dependence of the Josephson current by applying magnetic fields Hx and Hy in the direction parallel to the plane of the junction and magnetic field Hz in the direction perpendicular to the plane of the junction. When the perpendicular magnetic field Hz was applied to the Josephson junction, the main peak of the Fraunhofer pattern shifted from the origin of the (Hx and Hy) plane. We investigated why Josephson current is modulated by a perpendicular magnetic field Hz.
Terahertz characterization of tunable metamaterial based on electrically controlled nematic liquid crystal
Authors: Kowerdziej Rafał , Olifierczuk Marek , Parka Janusz , Wróbel Jerzy
Published: July 2014

The terahertz time domain spectroscopy (THz-TDS) system is used to determine the effects of an AC bias voltage on the tunable response of a metamaterial transducer. The tunability of the metamaterial structure, which is based on the rod-split-square resonator, is demonstrated at terahertz frequencies through electrical control of the nematic liquid crystal orientation. Experimental results show that the metamaterial device can be tuned effectively (with transmittance change of up to 19%) by changing the magnitude of the AC bias voltage from 0 to 300 V. This type of tunable metamaterial could find application in the development of devices operating in the THz frequency region for filtering, modulating, and switching of the electromagnetic signals.
Investigation into loss in ferrofluid magnetization
Authors: Li J. , Gong X. M. , Lin Y. Q. , Liu X. D. , Chen L. L. , Li J. M. , Mao H. , Li D. C.
Published: July 2014

Ferrofluids containing γ-Fe2O3/Ni2O3 nanoparticles (not chemically treated) were synthesized using water and mixed water–glycerol as carrier liquid and the ferrofluid viscosity was modified by varying the glycerol content in the carrier liquid. The apparent magnetization of the ferrofluids decreased with increasing glycerol content. The loss in magnetization is described by the ratio of effective magnetic volume fraction to physical volume fraction of nanoparticles in the ferrofluids as a characteristic parameter. We ascribe the loss to the formation of “dead aggregates” having a ring-like structure of closed magnetic flux rather than to any chemical reaction. Such dead aggregates exist in zero magnetic field and do not contribute to the magnetization in the low or high field regime, so that the effective magnetic volume fraction in the ferrofluids decrease. An increase in carrier liquid viscosity is similar to a weakening of the thermal effect, so the number of dead aggregates increases and the magnetization decreases in inverse proportion to the viscosity. This relationship between the apparent magnetization and ferrofluid carrier liquid viscosity can be termed the “viscomagnetic effect”.
Effect of medications with anti-cholinergic properties on cognitive
function, delirium, physical function and mortality: a systematic
review
Authors: Fox Chris , Smith Toby , Maidment Ian , Chan Wei-Yee , Bua Nelson , Myint Phyo Kyaw , Boustani Malaz , Kwok Chun Shing , Glover Michelle , Koopmans Imogen , Campbell Noll
Published: July 2014

Objectives: to determine the effect of drugs with anti-cholinergic properties on relevant health outcomes.

Design: electronic published and unpublished literature/trial registries were systematically reviewed. Studies evaluating medications with anti-cholinergic activity on cognitive function, delirium, physical function or mortality were eligible.

Results: forty-six studies including 60,944 participants were included. Seventy-seven percent of included studies evaluating cognitive function (n = 33) reported a significant decline in cognitive ability with increasing anti-cholinergic load (P < 0.05). Four of five included studies reported no association with delirium and increasing anti-cholinergic drug load (P > 0.05). Five of the eight included studies reported a decline in physical function in users of anti-cholinergics (P < 0.05). Three of nine studies evaluating mortality reported that the use of drugs with anti-cholinergic properties was associated with a trend towards increased mortality, but this was not statistically significant. The methodological quality of the evidence-base ranged from poor to very good.

Conclusion: medicines with anti-cholinergic properties have a significant adverse effect on cognitive and physical function, but limited evidence exists for delirium or mortality outcomes.
Montaigne and the Theatre of Conscience
Authors: MacPhail Eric
Published: July 2014

This article proposes a new reading of Montaigne's essay ‘De la gloire’ in the context of Ciceronian moral philosophy and in reference to Cicero's metaphor of the theatre of conscience. His essay explores the tension between the ethical ideal of the primacy of individual conscience and the demoralizing reality of the need for external sanctions to enforce moral and religious norms. This tension leads Montaigne to a candidly irreligious consideration of the instrumental value of religion in society.
Variation of the X-ray non-thermal emission in the Arches cloud
Authors: Clavel M. , Soldi S. , Terrier R. , Tatischeff V. , Maurin G. , Ponti G. , Goldwurm A. , Decourchelle A.
Published: July 2014

The origin of the iron fluorescent line at 6.4 keV from an extended region surrounding the Arches cluster is debated and the non-variability of this emission up to 2009 has favoured the low-energy cosmic ray origin over a possible irradiation by hard X-rays. By probing the variability of the Arches cloud non-thermal emission in the most recent years, including a deep observation in 2012, we intend to discriminate between the two competing scenarios. We perform a spectral fit of XMM–Newton observations collected from 2000 to 2013 in order to build the Arches cloud light curve corresponding to both the neutral Fe Kα line and the X-ray continuum emissions. We reveal a 30 per cent flux drop in 2012, detected with more than 4σ significance for both components. This implies that a large fraction of the studied non-thermal emission is due to the reflection of an X-ray transient source.
Diagnosing Diabetic Foot Osteomyelitis: Narrative Review and a Suggested 2-Step Score-Based Diagnostic Pathway for Clinicians
Authors: Markanday Anurag
Published: July 2014

The diabetic foot infection remains a major cause of morbidity and mortality in many patients and remains a challenging diagnosis for most clinicians. Diagnosis is largely based on clinical signs supplemented by various imaging tests. Magnetic resonance imaging (MRI) is not readily available to many clinicians, and bone biopsy, which is the accepted criterion standard for diagnosis, is rarely performed routinely. This evidence-based review and the proposed diagnostic scoring pathway substratifies the current International Working Group on the Diabetes Foot guidelines for diagnosing diabetic foot osteomyelitis into a convenient 2-step diagnostic pathway for clinicians. This proposed diagnostic approach will need further validation prospectively, but it can serve as a useful diagnostic tool during the initial assessment and management of diabetic foot infections. A MEDLINE search of English-language articles on diabetic foot osteomyelitis published between 1986 and March 2014 was conducted. Additional articles were also identified through a search of references from the retrieved articles, published guidelines, systematic reviews, and meta-analyses.
Toxocariasis After Slug Ingestion Characterized by Severe Neurologic, Ocular, and Pulmonary Involvement
Authors: Fellrath Jean-Marc , Magnaval Jean-François
Published: July 2014

Human toxocariasis is generally a benign, self-curing disease, and neurologic involvement is quite exceptional. In this study, we report a case of toxocariasis caused by ingestion of an unusual transport host, namely live slugs. The clinical picture comprised eosinophilic lung involvement with severe neurologic disorders in relation to vasculitis as well as retinal detachment.
High resolution melting analysis for the differentiation of Mycobacterium species
Authors: Issa Rahizan , Abdul Hatijah , Hashim Siti Hasmah , Seradja Valentinus H. , Shaili Nurul ‘Aishah , Hassan Nurul Akma Mohd
Published: July 2014

A quantitative real-time PCR (qPCR) followed by high resolution melting (HRM) analysis was developed for the differentiation of Mycobacterium species. Rapid differentiation of Mycobacterium species is necessary for the effective diagnosis and management of tuberculosis. In this study, the 16S rRNA gene was tested as the target since this has been identified as a suitable target for the identification of mycobacteria species. During the temperature gradient and primer optimization process, the melting peak (Tm) analysis was determined at a concentration of 50 ng DNA template and 0.3, 0.4 and 0.5 µM primer. The qPCR assay for the detection of other mycobacterial species was done at the Tm and primer concentration of 62 °C and 0.4 µM, respectively. The HRM analysis generated cluster patterns that were specific and sensitive to distinguished small sequence differences of the Mycobacterium species. This study suggests that the 16S rRNA-based real-time PCR followed by HRM analysis produced unique cluster patterns for species of Mycobacterium and could differentiate the closely related mycobacteria species.
Characteristics of microbial drug resistance and its correlates in chronic diabetic foot ulcer infections
Authors: Murali Thokur S. , Kavitha Shettigar , Spoorthi Jain , Bhat Deepika V. , Prasad Alevoor S. Bharath , Upton Zee , Ramachandra Lingadakai , Acharya Raviraj V. , Satyamoorthy Kapaettu
Published: July 2014

While virulence factors and the biofilm-forming capabilities of microbes are the key regulators of the wound healing process, the host immune response may also contribute in the events following wound closure or exacerbation of non-closure. We examined samples from diabetic and non-diabetic foot ulcers/wounds for microbial association and tested the microbes for their antibiotic susceptibility and ability to produce biofilms. A total of 1074 bacterial strains were obtained with staphylococci, Pseudomonas, Citrobacter and enterococci as major colonizers in diabetic samples. Though non-diabetic samples had a similar assemblage, the frequency of occurrence of different groups of bacteria was different. Gram-negative bacteria were found to be more prevalent in the diabetic wound environment while Gram-positive bacteria were predominant in non-diabetic ulcers. A higher frequency of monomicrobial infection was observed in samples from non-diabetic individuals when compared to samples from diabetic patients. The prevalence of different groups of bacteria varied when the samples were stratified according to age and sex of the individuals. Several multidrug-resistant strains were observed among the samples tested and most of these strains produced moderate to high levels of biofilms. The weakened immune response in diabetic individuals and synergism among pathogenic micro-organisms may be the critical factors that determine the delicate balance of the wound healing process.
Identifying mouse models for skin cancer using the Mouse Tumor Biology Database
Authors: Begley Dale A. , Krupke Debra M. , Neuhauser Steven B. , Richardson Joel E. , Schofield Paul N. , Bult Carol J. , Eppig Janan T. , Sundberg John P.
Published: July 2014

In recent years, the scientific community has generated an ever‐increasing amount of data from a growing number of animal models of human cancers. Much of these data come from genetically engineered mouse models. Identifying appropriate models for skin cancer and related relevant genetic data sets from an expanding pool of widely disseminated data can be a daunting task. The Mouse Tumor Biology Database (MTB) provides an electronic archive, search and analysis system that can be used to identify dermatological mouse models of cancer, retrieve model‐specific data and analyse these data. In this report, we detail MTB's contents and capabilities, together with instructions on how to use MTB to search for skin‐related tumor models and associated data.
Contributions of Medical Family Therapy to the Changing Health Care System
Authors: Doherty William J. , McDaniel Susan H. , Hepworth Jeri
Published: July 2014

Medical family therapy is a form of professional practice that uses a biopsychosocial approach and systemic family therapy principles in the collaborative treatment of individuals and families dealing with medical problems. It emerged out of the experience of family therapists working in primary medical care settings in the 1980s and 1990s. This article describes how contemporary medical family therapy can contribute to a transformed health care system in four areas: the patient experience of health care, the health of the population, the containment of health care costs, and enhanced practice environments.