bluuebunny/crossref_metadata_2025 huggingface dataset:
Interpersonal Stress and Poor Health
Authors: Aanes Mette M. , Mittelmark Maurice B. , Hetland Jørn
Published: March 2010

This paper investigated whether the lack of social connectedness, as measured by the subjective feeling of loneliness, mediates the well-known relationship between interpersonal stress and psychological distress. Furthermore, a relationship between interpersonal stress and somatic symptoms was hypothesized. The study sample included 3,268 women and 3,220 men in Western Norway. The main findings were that interpersonal stress was significantly related to psychological distress as well as to somatic symptoms, both directly and indirectly via paths mediated by loneliness. The size of the indirect effects varied, suggesting that the importance of loneliness as a possible mediator differs for depressive symptoms, anxiety symptoms, and somatic symptoms. In the case of depressive symptoms, more than 75% of the total effect was mediated through loneliness, while in the case of somatic symptoms just over 40% of the total effect was mediated through loneliness. This study supports the hypotheses that social connectedness mediates a relationship between interpersonal stress and psychological distress. The study also provides the first link between interpersonal stress, as measured by the Bergen Social Relationships Scale, and somatic symptoms, extending earlier research on the relationship between interpersonal stress and psychological distress.
Language and the Inner
Authors: Şimşek Ömer Faruk
Published: March 2010

The nexus between language and experience addresses the distinct, qualitative aspects of human experience or qualia. These qualitative aspects are important because, when people perceive a disconnect between language and experience, consequences for psychological health may follow. The research reported herein aimed to develop and validate a psychometric tool to assess perceptions of connection between language and experience. Six studies were conducted to confirm the factor structure of the Beliefs About the Functions of Language scale and to assess its construct validity. Two factors were derived and validated (viz. epistemic and communicative), which were shown to relate to mental health indicators in expected ways.
Long‐term variations of the Campi Flegrei, Italy, volcanic system as revealed by the monitoring of hydrothermal activity
Authors: Chiodini G. , Caliro S. , Cardellini C. , Granieri D. , Avino R. , Baldini A. , Donnini M. , Minopoli C.
Published: March 2010

Long‐duration time series of the chemical composition of fumaroles and of soil CO2 flux reveal that important variations in the activity of the Solfatara fumarolic field, the most important hydrothermal site of Campi Flegrei, occurred in the 2000–2008 period. A continuous increase of the CO2 concentrations and a general decrease of the CH4 concentrations are interpreted to be the consequence of the increment of the relative amount of magmatic fluids, rich in CO2 and poor in CH4, hosted by the hydrothermal system. Contemporaneously, the H2O‐CO2‐He‐N2 gas system shows remarkable compositional variations in the samples collected after July 2000 with respect to the previous ones, indicating the progressive arrival at the surface of a magmatic component different from that involved in the 1983–1984 episode of volcanic unrest (1983–1984 bradyseism). The change starts in 2000, concurrently with the occurrence of relatively deep, long‐period seismic events which were the indicator of the opening of an easy ascent pathway for the transfer of magmatic fluids toward the shallower, brittle domain hosting the hydrothermal system. Since 2000, this magmatic gas source is active and causes ground deformations and seismicity as well as the expansion of the area affected by soil degassing of deeply derived CO2. Even though the activity will most probably be limited to the expulsion of large amounts of gases and thermal energy, as observed in other volcanoes and in the past activity of Campi Flegrei, the behavior of the system in the future is, at the moment, unpredictable.
Relationships among properties of marine stratocumulus derived from collocated CALIPSO and MODIS observations
Authors: Hayes C. R. , Coakley J. A. , Tahnk W. R.
Published: March 2010

Collocated Moderate Resolution Imaging Spectroradiometer (MODIS) imagery and Cloud‐Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) 532 nm total attenuated backscatter coefficients were used to identify 50 km scale segments for ocean regions that had only a single layer of marine stratocumulus. On the basis of whether the underlying ocean surface was detected in the backscatter coefficients, the segments were separated into those for which all of the 1 km MODIS pixels were identified as being overcast (no surface detected) and those for which there were breaks in the cloud layer (surface detected). Cloud properties for the collocated MODIS pixels were obtained from the MODIS MOD06 cloud product and from a retrieval scheme designed to account for broken clouds within imager pixels. For the 50 km overcast segments the variations in optical depth, τ, and droplet effective radius, Re, obtained from the MOD06 and partly cloudy pixel retrievals were in agreement, and the variations in layer temperature were consistent with those inferred from the CALIPSO backscatter coefficients. In addition, the droplet effective radii retrieved separately using the 1.6, 2.1, and 3.7 μm MODIS reflectances were consistent with droplets growing as clouds thickened and mean values of dlnRe/dlnτ were close to 0.2, as predicted by adiabatic cloud parcel models. When the segments contained broken clouds, however, the droplet effective radii for the three near‐infrared wavelengths were inconsistent with droplets growing as clouds thickened and dlnRe/dlnτ departed from 0.2. This breakdown is thought to result from biases in the retrieved cloud properties caused by subpixel‐scale variations in liquid water amount and droplet radius.
Global evaluation of SCIAMACHY and MOPITT carbon monoxide column differences for 2004–2005
Authors: de Laat A. T. J. , Gloudemans A. M. S. , Aben I. , Schrijver H.
Published: March 2010

This paper presents a detailed global comparison of Scanning Imaging Absorption Spectrometer for Atmospheric Cartography (SCIAMACHY) and Measurement of Pollution in the Troposphere (MOPITT) carbon monoxide (CO) column measurements for the years 2004 and 2005. Qualitatively, spatiotemporal variations of SCIAMACHY and MOPITT are similar. Quantitative comparisons have been performed taking the effects of instrument noise errors, vertical sensitivities via the averaging kernel and a priori, different spatiotemporal sampling and clouds into account using simulated CO profiles from the TM4 model. SCIAMACHY and MOPITT CO columns are similar over tropical, subtropical, and Northern Hemisphere oceans as well as over boreal regions where SCIAMACHY and MOPITT agree to within 10% or 2 × 1017 molecules/cm2. The short‐wave infrared SCIAMACHY observations also provide information about lower tropospheric CO in Arctic and subarctic regions north of 60°N, where the MOPITT sensitivity is strongly reduced. South of 45°S, SCIAMACHY CO columns are 3–5 × 1017 molecules/cm2 smaller than MOPITT CO columns. Approximately 1.5 × 1017 molecules/cm2 (∼10%) of this difference is attributed to a bias in the SCIAMACHY CO columns, which is currently under investigation. The remaining difference is possibly related to MOPITT biases in this region. In the transition from oceans to dry desert regions, MOPITT CO total columns show a rapid increase of approximately 3 × 1017 molecules/cm2 (∼15%). While MOPITT and SCIAMACHY agree over oceans, MOPITT is approximately 5 × 1017 molecules/cm2 (∼25%) larger than SCIAMACHY results over dry land regions. The origin of this bias needs further investigation.
Associations between stratospheric variability and tropospheric blocking
Authors: Woollings T. , Charlton‐Perez A. , Ineson S. , Marshall A. G. , Masato G.
Published: March 2010

There is widely believed to be a link between stratospheric flow variability and stationary, persistent “blocking” weather systems, but the precise nature of this link has proved elusive. Using data from the ERA‐40 Reanalysis and an atmospheric general circulation model (GCM) with a well‐resolved stratosphere (HadGAM), it is shown that there are in fact several different highly significant associations, with blocking in different regions being related to different patterns of stratospheric variability. This is true in both hemispheres and in both data sets. The associations in HadGAM are shown to be very similar to those in ERA‐40, although the model has a tendency to underestimate both European blocking and the wave number 2 stratospheric variability to which this is related. Although the focus is on stratospheric variability in general, several of the blocking links are seen to occur in association with the major stratospheric sudden warmings. In general, the direction of influence appears to be upward, as blocking anomalies are shown to modify the planetary stationary waves, leading to an upward propagation of wave activity into the stratosphere. However, significant correlations are also apparent with the zonal mean flow in the stratosphere leading the occurrence of blocking at high latitudes. Finally, the underestimation of blocking is an enduring problem in GCMs, and an example has recently been given in which improving the resolution of the stratosphere improved the representation of blocking. Here, however, another example is given, in which increasing the stratospheric resolution unfortunately does not lead to an improvement in blocking.
Description and initial simulation of a dynamic bidirectional air‐surface exchange model for mercury in Community Multiscale Air Quality (CMAQ) model
Authors: Bash Jesse O.
Published: March 2010

Emissions of elemental mercury (Hg0) from natural processes are estimated to be as large as or larger than anthropogenic emissions and thus represent a critical process which must be accurately described in the modeling of the transport and fate of mercury. Recent ecosystem‐scale measurements indicate that a fraction of recently deposited mercury is recycled back into the atmosphere quickly, and that an atmospheric compensation point exists at background ambient concentrations. Modeled Hg0 emissions from natural sources are typically uncoupled from dry deposition estimates and unconstrained by air‐biosphere gradient processes. A module has been developed for the Community Multiscale Air Quality (CMAQ) model to parameterize concentration‐dependent processes of bidirectional mercury exchange. The Hg0 air‐surface exchange was modeled as a function of a dynamic compensation point. The compensation point is modeled as a function of sources and sinks of Hg0 in vegetation and soil media using partitioning coefficients. A box model simulation was run for five months and a CMAQ simulation with bidirectional (BIDI) and without bidirectional (BASE) mercury exchange was run for the month of July 2002. The BASE case modeling scenario estimated that 8.5% of the total mercury (Hg0 + Hg2 + PHg) deposited to terrestrial systems and 47.8% of the total mercury deposition to aquatic systems was re‐emitted as Hg0, while the re‐emission ratios were 70.4% and 52.5% in the base case. The BIDI case was in better agreement with recent estimates of mercury cycling using stable isotopic mass balance experiments.
On the spatial variability of the Martian elastic lithosphere thickness: Evidence for mantle plumes?
Authors: Grott M. , Breuer D.
Published: March 2010

The present day elastic lithosphere thickness at the Martian north pole has recently been constrained to De > 300 km and this is a factor of 3–4 larger than elastic thickness estimates for other Amazonian surface features like the Tharsis volcanoes. Here we present a model for the Martian elastic lithosphere thickness which takes the locally varying crustal thickness, the local concentration of heat‐producing elements, as well as variations of strain rate into account. The model predicts De = 196 km at the north pole today, whereas elastic thicknesses at the Tharsis volcanoes are best compatible with middle to late Amazonian loading ages. Therefore, although a large degree of spatial heterogeneity can be explained by the presented model, large elastic thicknesses in excess of 300 km cannot be reproduced. In order to fit all elastic thickness estimates derived from observations, mantle heat flux at the north pole needs to be reduced by 35%. However, this can only be reconciled with a bulk chondritic concentration of heat‐producing elements in the Martian interior if the excess heat is deposited elsewhere. Therefore, this argues for the presence of recently active mantle plumes, possibly underneath Tharsis. The size and strength of such a plume can be constrained by the elastic thickness at the Tharsis Montes and maximum average heat flux between 8 and 24 mW m‐2, corresponding to a central peak heat flux of 40 to 120 mW m−2, is consistent with the observations. Such a plume would leave a clear signature in the surface heat flux and should be readily detectable by in situ heat flux measurements.
Catchment export of carbon, nitrogen, and phosphorus across an agro‐urban land use gradient, Swan‐Canning River system, southwestern Australia
Authors: Petrone Kevin C.
Published: March 2010

Coastal regions in many regions of the world are under increasing pressure from the expansion of agriculture and urbanization associated with elevated N and P loading and eutrophication of coastal estuaries. I compared how mixed land use catchments deliver dissolved and particulate forms of C, N, and P in streamflow to the Swan‐Canning estuary that bisects Perth, Western Australia. Dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) composed the majority of the total C and N load, particulate C and N fluxes were minor, and P fluxes were evenly split between soluble reactive phosphorus and particulate/organic P. In contrast to current biogeochemical theory, DON export was dominant in urban and agricultural catchments in the low‐gradient environment of the Swan Coastal Plain, whereas NO3 export was a greater factor in higher‐gradient, forested catchments on the urban fringe. This trend suggests that hydrologic conditions that supported coastal wetlands prior to human development may still promote DON mobilization as well as dissolved inorganic nitrogen loss along hydrologic flow paths. Substantial variability in export of C, N, and P across catchments highlights the unique hydrologic properties of Australian catchments. Areal C, N, and P export was significantly related to catchment runoff which was lowest in a catchment with inland drainage, but greatest in urban catchments with impervious surfaces and shallow groundwater. The effective delivery of DOC and DON to aquatic ecosystems in urbanizing coastal catchments underscores the importance of restoration efforts that address hydrologic retention as well as the source and bioavailability of dissolved organic matter.
Wind sheltering of a lake by a tree canopy or bluff topography
Authors: Markfort Corey D. , Perez Angel L. S. , Thill James W. , Jaster Dane A. , Porté‐Agel Fernando , Stefan Heinz G.
Published: March 2010

A model is developed to quantify the wind sheltering of a lake by a tree canopy or a bluff. The experiment‐based model predicts the wind‐sheltering coefficient a priori, without calibration, and is useful for one‐dimensional (1‐D) lake hydrodynamic and water quality modeling. The model is derived from velocity measurements in a boundary layer wind tunnel, by investigating mean velocity profiles and surface shear stress development downwind of two canopies and a bluff. The wind tunnel experiments are validated with field measurements over an ice‐covered lake. Both wind tunnel and field experiments show that reduced surface shear stress extends approximately 50 canopy heights downwind from the transition. The reduction in total shear force on the water surface is parameterized by a wind‐sheltering coefficient that is related to the reduction of wind‐affected lake area. While all measurements are made on solid surfaces, the wind‐sheltering coefficient is shown to be applicable to the lake surface. Although several canopy characteristics, such as its height, aerodynamic roughness, and its porosity affect the transition of velocity profiles and surface shear stress onto a lake, a relationship based on canopy height alone provides a sufficiently realistic estimate of the wind‐sheltering coefficient. The results compare well with wind‐sheltering coefficients estimated by calibration of lake water temperature profile simulations for eight lakes.
Streptococcus pyogenes cytolysin‐mediated translocation does not require pore formation by streptolysin O
Authors: Magassa N'Goundo , Chandrasekaran Sukantha , Caparon Michael G
Published: March 2010

Bacterial toxin injection into the host cell is required for the virulence of numerous pathogenic bacteria. Cytolysin‐mediated translocation (CMT) of Streptococcus pyogenes uses streptolysin O (SLO) to translocate the S. pyogenes nicotinamide adenine dinucleotide‐glycohydrolase (SPN) into the host cell cytosol, resulting in the death of the host cell. Although SLO is a pore‐forming protein, previous studies have shown that pore formation alone is not sufficient for CMT to occur. Thus, the role and requirement of the SLO pore remains unclear. In this study, we constructed various S. pyogenes strains expressing altered forms of SLO to assess the importance of pore formation. We observed that SLO mutants that are unable to form pores retain the ability to translocate SPN. In addition, SPN translocation occurs after inhibition of actin polymerization, suggesting that CMT occurs independently of clathrin‐mediated endocytosis. Moreover, despite the ability of mutants to translocate SPN, their cytotoxic effect requires SLO pore formation.
Thermoelectric heating of Ge2Sb2Te5 in phase change memory devices
Authors: Suh Dong-Seok , Kim Cheolkyu , Kim Kijoon H. P. , Kang Youn-Seon , Lee Tae-Yon , Khang Yoonho , Park Tae Sang , Yoon Young-Gui , Im Jino , Ihm Jisoon
Published: March 2010

We report on the demonstration of the active thermoelectric application to nanometer-scaled semiconductor devices. The thermoelectric heating already exists during programming in conventional phase change memory (PRAM) cells, which is only a minor supplement to Joule heating. Here, by rigorously designing devices, we have demonstrated an unprecedentedly high efficiency of PRAM, where the majority of the heat is supplied by the thermoelectric effect.
Experimental and numerical verification of microplasma assembly for novel electromagnetic media
Authors: Sakai Osamu , Naito Teruki , Tachibana Kunihide
Published: March 2010

Microplasmas have a number of potential roles to control propagating electromagnetic waves. This report focuses on novel physics of periodic microplasma assembly for electromagnetic media, which is verified by experimental results and analyzed by numerical methods. Using an assembly composed of microplasmas, novel functions are expected due to its complex dielectric function arising from dielectric and lossy properties. The dielectric property creates photonic band gaps, and the lossy property drastically changes transmittance around the photonic band gaps, leading to an attenuation gap. As a result, a “complex” dispersion relation or a band diagram in the three-dimensional space of real and imaginary wavenumbers and wave frequency will open new possibilities to control electromagnetic waves by complex-variable filters composed of microplasma assemblies.
Meromorphic solutions of a third order nonlinear differential equation
Authors: Conte Robert , Ng Tuen-Wai
Published: March 2010

We prove that all the meromorphic solutions of the nonlinear differential equation c0u‴+6u4+c1u″+c2uu′+c3u3+c4u′+c5u2+c6u+c7=0 are elliptic or degenerate elliptic, and we build them explicitly.
Shock experiments and numerical simulations on low energy portable electrically exploding foil accelerators
Authors: Saxena A. K. , Kaushik T. C. , Gupta Satish C.
Published: March 2010

Two low energy (1.6 and 8 kJ) portable electrically exploding foil accelerators are developed for moderately high pressure shock studies at small laboratory scale. Projectile velocities up to 4.0 km/s have been measured on Kapton flyers of thickness 125 μm and diameter 8 mm, using an in-house developed Fabry–Pérot velocimeter. An asymmetric tilt of typically few milliradians has been measured in flyers using fiber optic technique. High pressure impact experiments have been carried out on tantalum, and aluminum targets up to pressures of 27 and 18 GPa, respectively. Peak particle velocities at the target-glass interface as measured by Fabry–Pérot velocimeter have been found in good agreement with the reported equation of state data. A one-dimensional hydrodynamic code based on realistic models of equation of state and electrical resistivity has been developed to numerically simulate the flyer velocity profiles. The developed numerical scheme is validated against experimental and simulation data reported in literature on such systems. Numerically computed flyer velocity profiles and final flyer velocities have been found in close agreement with the previously reported experimental results with a significant improvement over reported magnetohydrodynamic simulations. Numerical modeling of low energy systems reported here predicts flyer velocity profiles higher than experimental values, indicating possibility of further improvement to achieve higher shock pressures.
Phase-integral solution of the radial Dirac equation
Authors: Linnæus Staffan
Published: March 2010

A phase-integral (WKB) solution of the radial Dirac equation is constructed, retaining perfect symmetry between the two components of the wave function and introducing no singularities except at the classical transition points. The potential is allowed to be the time component of a four-vector, a Lorentz scalar, a pseudoscalar, or any combination of these. The key point in the construction is the transformation from two coupled first-order equations constituting the radial Dirac equation to a single second-order Schrödinger-type equation. This transformation can be carried out in infinitely many ways, giving rise to different second-order equations but with the same spectrum. A unique transformation is found that produces a particularly simple second-order equation and correspondingly simple and well-behaved phase-integral solutions. The resulting phase-integral formulas are applied to unbound and bound states of the Coulomb potential. For bound states, the exact energy levels are reproduced.
Phase-field simulation of phase coarsening at ultrahigh volume fractions
Authors: Wang K. G. , Ding X. , Chang Kunok , Chen L. Q.
Published: March 2010

In this paper, the dynamics of phase coarsening at ultrahigh volume fractions (0.9≤VV≤0.96) is first studied based on two-dimensional phase-field simulations by numerically solving the time-dependent Ginzburg–Landau and Cahn–Hilliard equations. It is shown that the cubic average radius of particles is approximately proportional to time that is in good agreement with one of experimental observations. The microstructural evolutions for different ultrahigh volume fractions are shown. The scaled particle size distribution as functions of the dispersoid volume fraction is presented. The interesting finding is that the particle size distribution derived from our simulations at ultrahigh volume fractions is close to Wagner’s particle size distribution due to interface-controlled ripening rather than Hillert’s grain size distribution in grain growth. The changes of shapes of particles are carefully studied with increase in volume fraction. It is found that some liquid-filled triple junctions are formed as a result of particle shape accommodation at ultrahigh volume fraction, VV≈0.96.
Mechanical properties of defective single wall carbon nanotubes
Authors: Shtogun Yaroslav V. , Woods Lilia M.
Published: March 2010

First principle density functional theory calculations for radially deformed and defective single wall (8,0) carbon nanotube are reported. Structural changes in terms of radial cross-sectional geometry and bond length changes are studied for different values of the applied strain for all types of investigated deformations and defects. Various characteristic deformation and defect energies are shown as a function of the applied deformation. The nonlinear elastic properties of the radially deformed and defective (8,0) nanotube are also investigated in terms of the strain energy and applied force.
Strengthening due to Cr-rich precipitates in Fe–Cr alloys: Effect of temperature and precipitate composition
Authors: Terentyev D. , Hafez Haghighat S. M. , Schäublin R.
Published: March 2010

Molecular dynamics (MD) simulations were carried out to study the interaction between nanometric Cr precipitates and a 1/2 ⟨111⟩{110} edge dislocation (ED) in pure Fe and Fe-9 at. % Cr (Fe-9Cr) random alloy. The aim of this work is to estimate the variation in the pinning strength of the Cr precipitate as a function of temperature, its chemical composition and the matrix composition in which the precipitate is embedded. The dislocation was observed to shear Cr precipitates rather than by-pass via the formation of the Orowan loop, even though a pronounced screw dipole was emerged in the reactions with the precipitates of size larger than 4.5 nm. The screw arms of the formed dipole were not observed to climb thus no point defects were left inside the sheared precipitates, irrespective of simulation temperature. Both Cr solution and Cr precipitates, embedded in the Fe-9Cr matrix, were seen to contribute to the flow stress. The decrease in the flow stress with temperature in the alloy containing Cr precipitates is, therefore, related to the simultaneous change in the matrix friction stress, precipitate resistance, and dislocation flexibility. Critical stress estimated from MD simulations was seen to have a strong dependence on the precipitate composition. If the latter decreases from 95% down to 80%, the corresponding critical stress decreases almost as twice. The results presented here suggest a significant contribution to the flow stress due to the α−α′ separation, at least for EDs. The obtained data can be used to validate and to parameterize dislocation dynamics models, where the temperature dependence of the obstacle strength is an essential input data.
Influence of crystal anisotropy on elastic deformation and onset of plasticity in nanoindentation: A simulational study
Authors: Ziegenhain Gerolf , Urbassek Herbert M. , Hartmaier Alexander
Published: March 2010

Using molecular-dynamics simulation we simulate nanoindentation into the three principal surfaces—the (100), (110), and (111) surface—of Cu and Al. In the elastic regime, the simulation data agree fairly well with the linear elastic theory of indentation into an elastically anisotropic substrate. With increasing indentation depth, the effect of pressure hardening becomes visible. When the critical stress for dislocation nucleation is reached, even the elastically isotropic Al shows a strong dependence of the force-displacement curves on the surface orientation. After the load drop, when plasticity has set in, the influence of the surface orientation is lost, and the contact pressure (hardness) becomes independent of the surface orientation.
Highly sensitive frequency metrology for optical anisotropy measurements
Authors: Bailly Gilles , Thon Raphaël , Robilliard Cécile
Published: March 2010

In this paper we present a novel apparatus aimed at measuring very small birefringences and anisotropies and based on frequency metrology and not on polarimetry as usual. In our experiment, a very high finesse resonant cavity is used to convert the phase difference into a resonance frequency difference, which can then be measured with very high accuracy. We describe the setup and present the results of experimental tests, which exhibited a sensitivity δn≃2×10−18, allowing for the measurement of long-predicted magnetoelectro-optical effects in gases. Since the shot-noise limited sensitivity of our apparatus lies well below the state-of-the-art sensitivity, frequency metrology appears as a promising technique for small birefringence measurements.
Time-resolved stereoscopic particle image velocimetry investigation of the entrainment in the near field of circular and daisy-shaped orifice jets
Authors: El Hassan Mouhammad , Meslem Amina
Published: March 2010

The flow in the initial region of two jets, namely, a circular orifice jet and a lobed orifice jet, is considered in the present paper. The role played by the Kelvin–Helmholtz (K-H) azimuthal rings and the streamwise vortices in the entrainment process of both jets have been qualitatively and quantitatively analyzed, for a Reynolds number of 3600. This has been achieved using the high speed stereoscopic particle image velocimetry measurements and a proper orthogonal decomposition (POD) analysis. The mean entrainment rate observed in the daisy-shaped jet is higher than that of the circular jet. It is found that a strong correlation exists between the entrainment rate and the K-H vortex dynamics for the circular jet. The entrainment is mainly produced in the upstream part of the K-H ring as well as in the braid region where the streamwise vortices appear. In the downstream part of the K-H ring, the flow expands from the jet core to the surrounding. In the lobed jet, the amplitude of the entrainment variation is smaller than in the circular jet at the same axial position. The flow dynamics observed in the region of axis switching is highly complex. A snapshot POD analysis is performed to bring out the individual role played by the azimuthal and the streamwise vortices on the entrainment for both the jets. In the circular jet, the POD analysis confirms quantitatively the role of the K-H vortices as well as the streamwise vortices on jet entrainment. In the lobed jet, in addition to the main role of the streamwise vortex pairs in the entrainment, the K-H vortex also plays an undeniable role on the entrainment. In the experiments conducted, a steep rise in the momentum flux is observed for the axis-switching region of the lobed jet. The longitudinal distribution of the mean entrainment ratio of the daisy jet corroborates with that of the averaged streamwise vorticity and with the maximum streamwise vorticity. In the region of the axis switching, an important decrease in amplitude of the turbulent kinetic energy is evidenced.
A sensitive near-field microscope for thermal radiation
Authors: Kajihara Yusuke , Kosaka Keishi , Komiyama Susumu
Published: March 2010

A scattering-type scanning near-field optical microscope in long-wavelength infrared (LWIR) region is developed by using an extremely sensitive detector, called the charge-sensitive infrared phototransistor. A tungsten probe attached to a quartz tuning fork is controlled in shear-force mode. Evanescent wave at a sample surface is periodically scattered by slowly (2 Hz) modulating the probe in the direction normal to the sample surface. Near-field microscopy of thermal LWIR radiation from room-temperature Au/GaAs gratings is demonstrated without using any external illumination or excitation. Achieved spatial resolution is better than 300 nm.
Low-crosstalk bifurcation detectors for coupled flux qubits
Authors: de Groot P. C. , van Loo A. F. , Lisenfeld J. , Schouten R. N. , Lupaşcu A. , Harmans C. J. P. M , Mooij J. E.
Published: March 2010

We present experimental results on the crosstalk between two ac-operated dispersive bifurcation detectors, implemented in a circuit for high-fidelity readout of two strongly coupled flux qubits. Both phase-dependent and phase-independent contributions to the crosstalk are analyzed. For proper tuning of the phase the measured crosstalk is 0.1% and the correlation between the measurement outcomes is less than 0.05%. These results show that bifurcative readout provides a reliable and generic approach for multipartite correlation experiments.
An investigation of string cavitation in a true-scale fuel injector flow geometry at high pressure
Authors: Reid B. A. , Hargrave G. K. , Garner C. P. , Wigley G.
Published: March 2010

String cavitation has been studied in an optical automotive size fuel injector with true-scale flow geometry at injection pressures of up to 2050 bar. The multihole nozzle geometry studied allowed observation of the hole-to-hole vortex interaction and, in particular, that of a bridging vortex in the sac region between the holes. A dependency on Reynolds number was observed in the formation of the visible, vapor filled vortex cores. Above a threshold Reynolds number, their formation and appearance during a 2 ms injection event was repeatable and independent of upstream pressure and cavitation number.
Magnetic and optical properties of nanocorrugated Co films
Authors: Sapozhnikov M. V. , Gusev S. A. , Rogov V. V. , Ermolaeva O. L. , Troitskii B. B. , Khokhlova L. V. , Smirnov D. A.
Published: March 2010

Nanostructured Co films were prepared on the top of a polymethyl methacrylate (PMMA) colloidal crystals by magnetron sputtering. Optical reflectance spectra were studied in the range of near UV, IR, and visible light for p- and s-polarizations. Valleys were observed in the spectra and their positions scaled with the PMMA sphere diameter. Both the surface plasmon resonance and the dipole resonance of single Co nanocaps should be considered to explain the obtained results. Magneto-optic measurements showed the qualitative change of the magnetization curve and the enhancement of magneto-optic rotation at wavelength λ=632 nm in comparison with the control Co film.
Coherent collisions of infrared self-trapped beams in photorefractive InP:Fe
Authors: Alonzo Massimo , Dan Cristian , Wolfersberger Delphine , Fazio Eugenio
Published: March 2010

In this paper, we experimentally demonstrate collisions between two copropagating parallel coherent beams inside the photorefractive semiconductor iron doped indium phosphide (InP:Fe) at λ=1064 nm.
Contactless mobility measurements of inversion charge carriers on silicon substrates with SiO2 and HfO2 gate dielectrics
Authors: Everaert J. L. , Rosseel E. , Dekoster J. , Pap A. , Meszaros A. , Kis-Szabo K. , Pavelka T.
Published: March 2010

A method is described to determine the mobility of inversion charge carriers on Si substrates with SiO2 and HfO2 gate dielectrics. It is a completely contactless method combining corona charge and charge spreading metrology. [Patent Application Nos. EP 07118673 and U.S. 60940594.] It is shown that from such measurements mobility of inversion charge carriers can be calculated as a function of the effective electric field. The resulting mobility curves are comparable to those found in transistors.
Branching induced faceting of Si nanotrees
Authors: Doerk Gregory S. , Radmilovic Velimir , Maboudian Roya
Published: March 2010

The sidewalls of silicon nanotree trunks grown by the vapor-liquid-solid mechanism with branches seeded by Au surface migration are shown to exhibit strong sawtooth nanofaceting in the region of branching. For Si nanowires grown along the ⟨111⟩ direction, facets found after Au surface migration are identified with the {111} and {113} crystallographic planes. These facets differ from those found on the fully synthesized Si nanotrees, which occur on {111} and {100} planes. We hypothesize that the facets found on the nanotrees are composed of the basal structures of the branches and are induced by branch nucleation.
On the Superhydrophobic Properties of Crystallized Stearic Acid
Authors: Joseph Kyle R. , Neto Chiara
Published: March 2010

A surface coating formed by stearic acid (SA) crystals was prepared by repeatedly dipping a silicon substrate into a SA solution and drying it in air. Scanning electron microscopy imaging revealed that the surface roughness of the coating increases with each dip-and-dry cycle. The coating appears as a carpet of hydrophobic ‘blades’, and is superhydrophobic (after 20 dipping cycles advancing contact angle ~160°), even after immersion in water for up to 2 h. This simple method could be applied to large areas, making this an interesting alternative to high-tech surface modification techniques.
Phosphonium and Ammonium Ionic Liquids with Aromatic Anions: Synthesis, Properties, and Platinum Extraction
Authors: Stojanovic Anja , Kogelnig Daniel , Fischer Lisa , Hann Stephan , Galanski Markus , Groessl Michael , Krachler Regina , Keppler Bernhard K.
Published: March 2010

Several hydrophobic long-chain quaternary ammonium and phosphonium ionic liquids (ILs) with functionalized aromatic anions were prepared following a metathesis route using tricaprylmethylammonium chloride (Aliquat 336) and trihexyl(tetradecyl)phosphonium chloride (Cyphos IL101) as precursors. The incorporation of aromatic anions bearing hydroxy-, methoxy-, thiol-, and thioether functionalities as well as tetraphenylborate anions resulted in an increased chemical stability of the ILs and an alteration of their physico-chemical properties. Furthermore, aromatic anions significantly decreased the water solubility and water uptake of both ammonium and phosphonium-based ILs. Thiol- and thioether ILs were applied for the extraction of platinum from aqueous phase using liquid phase micro-extraction. Time dependent studies showed a rapid elimination of up to 95% platinum after 30 min. With a leaching of the anion <0.01 wt-% into the aqueous media, the evaluated ILs were found to be suitable as extracting agents for platinum from aqueous solutions.
Theoretical Investigation on Structures and Stabilities of CuXenZ (n = 1 - 3, Z = - 1, 0, +1) Clusters
Authors: Xinying Li , Senfeng Wu , Chengfang Zhou , Yongfang Zhao
Published: March 2010

The structures and stabilities of CuXe
n

Z
(n = 1–3, Z = –1, 0, +1) cluster series at the CCSD(T) theoretical level have been investigated. Herein, it is shown that the cations are more stable and have more compact geometries than the anions and neutrals. The role of the interaction is explained using the natural bond orbital, population, and electron density analysis.
Applying Bi-directional Jarzynski Methods to Quasi-equilibrium States
Authors: Reid James C. , Williams Stephen R. , Searles Debra J.
Published: March 2010

Measuring free energy differences between states is of fundamental importance to understanding and predicting the behaviour of thermodynamic systems. The Jarzynski equality provides a method for measuring free energy differences using non-equilibrium work paths and represents a major advance of modern thermodynamics. Recent work has extended the theory by using work paths in both directions between the states to improve the accuracy of the free energy measurement. It has also been shown that the Jarzynski equality can be adapted to measure the free energy of quasi-equilibrium systems such as glasses. Here we combine these advances to accurately measure the free energy difference between a glassy state and equilibrium using bi-directional methods. For this system however, the result is not as accurate as that achieved using the work evaluated in a single direction.
Binding Mode Prediction of PDE4 Inhibitors: A Comparison of Modelling Methods
Authors: Neale Diana S. , Thompson Philip E. , White Paul J. , Chalmers David K. , Yuriev Elizabeth , Manallack David T.
Published: March 2010

Molecular modelling is widely used in support of medicinal chemistry programs, with several theoretical approaches used in attempts to expedite drug discovery. In this study, three methods – molecular docking (Glide), shape similarity (ROCS), and pharmacophore modelling (Phase) – were evaluated for their ability to reproduce experimentally determined binding modes of 25 PDE4 inhibitors, identified by X-ray crystallography. Molecular docking was able to provide a good approximation (RMSD less than 2 Å) in 59% of cases, when considering the top binding pose. The pairwise comparisons, using molecular shape similarity, gave good matches in 42% of cases. Pharmacophore models were unable to predict good binding modes for a series of PDE4 inhibitors.
1,4,7-Tricarboxymethyl-1,4,7-triazacyclononane Copper Catalyzed Oxidative Polymerization to Form Poly(2,6-dimethyl-1,4-phenylene oxide) in Water
Authors: Pant Sweta , Hearn Milton T. W. , Saito Kei
Published: March 2010

The copper(II) complex of the water soluble ligand 1,4,7-tricarboxymethyl-1,4,7-triazacyclononane has been employed as a catalyst for the oxidative polymerization of 2,6-dimethylphenol using alkaline water as the solvent. With this catalytic system, the polymer, poly(2,6-dimethyl-1,4-phenylene oxide), was successfully obtained with suppression of the formation of the quinone by-product, 4-(3,5-dimethyl-4-oxo-2,5-cyclo-hexadienylidene)-2,6-dimethyl-2,5-cyclohexadienone, during the polymerization process.
Asymmetric Synthesis of a Hydroxylated Nine-membered Lactone from Tartaric Acid using the Claisen Rearrangement
Authors: Wong Leon S.-M. , Turner Kathleen A. , White Jonathan M. , Holmes Andrew B. , Ryan John H.
Published: March 2010

The synthesis of a hydroxylated vinyl-appended lactone, in five synthetic steps from tartaric acid, is reported. The C2-symmetrical bis-vinyl diol 12 was converted into the ketene acetal 14 via methylenation of the cyclic carbonate 13 or thermal elimination of benzeneselenenic acid from the selenoxide 17. In both cases, the in situ generated ketene acetal 14 underwent spontaneous Claisen rearrangement to give the nine-membered lactone (+)-15. Lactones of this type are potentially advanced precursors to simplified eleutherobin analogues or other medium-ring lactone natural products.
Synthesis of the Leu - Trp Component of the Celogentin Family of Cyclic Peptides Through a C - H Activation - Cross-Coupling Strategy
Authors: Li Barbara T. Y. , White Jonathan M. , Hutton Craig A.
Published: March 2010

A bioinspired approach to the central leucine(C3)–tryptophan(C6) cross-linked moiety present in the celogentin family of cyclic peptide natural products was achieved. The key transformation was enabled through a palladium-catalyzed C–H activation–cross-coupling of leucine quinoline amide and 6-iodotryptophan derivatives. X-Ray crystallographic analysis of a β-(indol-6-yl)-leucine derivative confirms the stereochemistry of the cross-linked adduct matches that of the natural products. The method enables the preparation of the Leu–Trp adduct as a single stereoisomer from l-leucine and l-tryptophan.
Genetic variability for root morph-architecture traits and root growth dynamics as related to phosphorus efficiency in soybean
Authors: Ao Junhua , Fu Jiabing , Tian Jiang , Yan Xiaolong , Liao Hong
Published: March 2010

Root morphology and architecture are believed to be important for plant phosphorus (P) efficiency, but their genetic information is relatively scarce. In the present study, a field and a specially designed minirhizotron experiments were conducted using two soybean (Glycine max L. Merr.) genotypes and their 88 recombinant inbred lines (RILs) to elucidate the genetic variability for root morph-architecture traits and root growth dynamics as related to P efficiency in soybean. The results indicated that the root morph-architecture traits were continually segregated in the RILs with a normal distribution, indicating which are possibly controlled by quantitative trait loci. Significantly positive correlations were found between root and P traits, suggesting feasibility of screening P efficient genotype through simple selection of root traits in field. Most root morph-architecture traits were closely correlated, showing a coordinating contribution to P efficiency. Furthermore, root morphological traits always had higher heritability than architecture traits, thus, could serve as more reliable index in field selection. The dynamic parameters of root growth from the minirhizotron experiment showed that the P efficient genotype established longer and larger root system with preferring distribution in surface layer and also kept more active roots, therefore, had a better growth performance in field, than the P-inefficient genotype. Taken together, this is the first report on in situ root growth dynamics and its relation to P efficiency using minirhizotron systems in crops. Our findings help to better understand the relationships between P efficiency and root traits and, thus, facilitate development of P efficient genotypes in crops.
Mitochondrial enzymes and citrate transporter contribute to the aluminium-induced citrate secretion from soybean (Glycine max) roots
Authors: Xu Muyun , You Jiangfeng , Hou Ningning , Zhang Hongmei , Chen Guang , Yang Zhenming
Published: March 2010

The concentration of soluble aluminium (Al) in the soil solution increases at low pH and the prevalence of toxic Al3+ cations represent the main factor limiting plant growth on acid soils. Citrate secretion from roots is an important Al-tolerance mechanism in many species including soybean. We isolated mitochondria from the roots of an Al-resistant soybean (Glycine max L.) cv. Jiyu 70 to investigate the relationship between citrate metabolism and Al-induced citrate secretion. Spectrophotometric assays revealed that the activities of mitochondrial malate dehydrogenase and citrate synthase increased and aconitase decreased with increasing of Al concentration (0–50 µM) and duration of Al treatment (30 µM Al, 0.5–9 h). Al-induced citrate secretion was inhibited by the citrate synthase inhibitor suramin, and enhanced by the aconitase inhibitor fluorocitric acid. Mersalyl acid, an inhibitor of a citrate carrier located in mitochondria membrane, also suppressed Al-induced citrate secretion. Transcript level of the mitochondrial citrate synthase gene increased in soybean roots exposed to Al, whereas expression of aconitase showed no significant difference. Expression of Gm-AlCT, a gene showing homology to Al-activated citrate transporters was also induced after 4 h in Al treatment. The Al-dependent changes in activity and expression of these enzymes are consistent with them supporting the sustained release of citrate from soybean roots.
Homeostasis of respiration under drought and its important consequences for foliar carbon balance in a drier climate: insights from two contrasting Acacia species
Authors: Gimeno Teresa E. , Sommerville Katy E. , Valladares Fernando , Atkin Owen K.
Published: March 2010

Under drought, when photosynthesis (A) is impaired, foliar respiration (R) becomes crucial to estimate plant carbon balance. However, the effects of drought on R remain unclear and little is known about differences between congeners with divergent anatomy. In this study we compared the physiological response to imposed drought in plants of two Acacia species: Acacia pycnantha Benth. and Acacia floribunda (Vent.) Willd. in a controlled environment. We subjected half of the plants to two desiccation cycles. Relative water content (RWC), the ratio of variable to maximum fluorescence (Fv/Fm), phyllode dark respiration (Rdark), stomatal conductance to water (gs), light-saturated photosynthesis (Asat) were monitored. Drought significantly reduced RWC, gs, Fv/Fm, and Asast; increased the instantaneous water use efficiency in the species with higher foliage mass per area (FMA) (A. pycnantha) and did not have any significant effect on Rdark but increased the Rdark/Asat ratio. Although the shape of the response to drought of both species was similar, the two species differed in the magnitude in the increase of the Rdark/Asat ratio, with drought-mediated increases in Rdark/Asat being greater in A. floribunda than in A. pycnantha; the latter also showing greater recovery of photosynthesis. Collectively, our results highlight the extent to which drought alters the carbon balance of the two selected species. The homeostasis of Rdark under drought is particularly relevant within a climate change scenario where more severe and frequent drought episodes are predicted to occur.