bluuebunny/crossref_metadata_2025 huggingface dataset:
Action de l'extrait de feuilles de vigne rouge AS 195 dans l'insuffisance veineuse chronique
Authors: Monsieur  , Van Snick
Published: February 2006

La vitesse d'action de l'extrait de feuilles de vigne rouge AS 195 a été étudiée dans 39 patients souffrant d'insuffisance veineuse chronique (IVC) de stade I ou II selon la classification de Widmer (stade 2 à 4 de la classification CEAP internationale). Les patients inclus dans l'étude présentaient tous un certain degré d'oedème et environ 20% des insuffisants veineux chroniques des plaintes cliniques. Les patients ont reçu 360 mg d'extrait à raison de deux prises par jour de 180 mg pendant six semaines. Les paramètres étudiés ont été la mesure du volume de la jambe par un pléthysmographe à eau, la mesure de la circonférence de la jambe à une hauteur fixée et des critères subjectifs tels qu'une échelle de sensation de lourdeur/douleur dans les jambes. Un effet net et significatif a été observé déjà après deux semaines de traitement. Cet effet se maintient et se renforce légèrement après quatre et six semaines sur les trois paramètres testés dans cette étude tant sur les symptômes subjectifs qu'objectifs. L'évolution du volume du mollet est statistiquement significative après 2, 4 et 6 semaines. Le volume du mollet diminue en moyenne de 26.3 ml après 2 semaines (t=−5.37 p<0.001), 29.8 ml après 4 semaines (t=−6.44 p<0.001) et 32.7 ml après 6 semaines (t=−7.67 p<0.001). L'évolution de l'intensité de la sensation de lourdeur-douleur est aussi statistiquement significative après 2, 4 et 6 semaines. L'intensité, mesurée sur une échelle analogique allant de 0 à 10, diminue en moyenne de 2.2 points après 2 semaines (t=−8.21 p<0.001), 2.6 points après 4 semaines (t=−10.93 p<0.001) et 2.6 points après 6 semaines (t=−10.75 p<0.001). Trois patients ont arrêté prématurément pour des raisons non liées au traitement ou à la maladie veineuse. Dans l'ensemble, les traitements ont été bien tolérés. L'analyse de ces différents paramètres démontre l'efficacité rapide de l'extrait de Vitis viniferae Folia AS 195 dans les insuffisances chroniques veineuses.
Eosinophile Ösophagitis: Eine neue Entität?
Authors: Straumann
Published: February 2006

Die Eosinophile Ösophagitis (EE), erstmals vor gut zehn Jahren als eigenständige Entität erkannt, ist eine chronisch-persistierende Ösophagus-Entzündung. Ursprünglich wurde die EE als extreme Rarität angesehen. Ihre Häufigkeit nimmt aber kontinuierlich zu und zur Zeit ist bereits mindestens 1 Patient auf 4000 Einwohnern von dieser Affektion befallen. Die Krankheit weist eine auffallende Prädilektion für das männlichen Geschlecht auf. Sie kann sich sowohl im Kindes- als auch im jüngeren Erwachsenenalter manifestieren. Das Leitsymptom der EE ist eine Dysphagie für geformte Speisen, mit dem permanent drohenden Risiko einer Bolusimpaktierung. Endoskopisch ist die EE schwierig zu erkennen, da die Veränderungen oftmals diskret oder aber verwirrend sind. Die Krankheit wird letztlich anhand ihrer typischen Anamnese vermutet, die Diagnose aber wird histologisch gestellt, wobei eine Infiltration der Ösophagusmukosa mit mindestens 24 eosinophilen Granulozyten/HPF verlangt wird. Das Hauptrisiko einer langdauernden und unbehandelten EE besteht in einer Fibrosierung des Ösophagus mit konsekutiver Ausbildung einer stenosierenden Striktur. Zur Therapie werden Kortikosteroide in systemischer und topischer Form, Leukotrien Antagonisten sowie hypoallergene Diäten empfohlen.
Spinale epidurale Hämatome (SEDH)
Authors: Berg  , Ott  , Glücker
Published: February 2006

Gerade weil das spinale epidurale Hämatom (SEDH) eine seltene Diagnose ist und in der Regel unter Notfallbedingungen lediglich eine CT-Untersuchung verfügbar ist, sollte bei entsprechender unklarer spinaler Symptomatik der Spinalkanal vergrössert rekonstruiert werden. Eine ergänzende spinale MRT-Untersuchung ist häufig diagnostisch wegweisend, u.a. bei einer differentialdiagnostischen Abgrenzung gegenüber vaskulären Malformationen oder primären und sekundären neoplastischen Läsionen. Gegebenenfalls kann in Ausnahmefällen eine DSA zur Operationsplanung ergänzt werden. Eine rasche diagnostische Abklärung ist für eine rechtzeitige neurochirurgische Hämatomausräumung bedeutend, um neurologische Spätschäden abzuwenden bzw. zu minimieren.
Individual and Dyadic Coping Strategies in the Aftermath of a Traumatic Experience
Authors: Kramer Ueli , Ceschi Grazia , Van der Linden Martial , Bodenmann Guy
Published: February 2006

This study was designed to explore individual and dyadic coping strategies in the aftermath of a traumatic event. Eighteen persons having experienced a physical assault or a road accident within six to twelve months before the study, and eighteen matched control persons were recruited together with their partners. Each participant and his/her partner filled in several questionnaires on individual and dyadic coping strategies, level of stress and PTSD-symptomatology. Results indicate that participants having experienced a trauma, compared to controls, report a general lack of dyadic coping and, when facing daily hassles, specific decreases in individual coping strategies. These differences are discussed in the context of marital coping processes.
The Role of Decision Biases in Semantic Priming Effects
Authors: Duscherer Katia , Holender Daniel
Published: February 2006

At least a part of semantic priming effects observed in binary decision tasks is supposed to be caused by decision biases. A semantic relationship between prime and target could positively bias a “yes” response, whereas the absence of a relationship would instead favour a “no” response to the same target. We tested this assumption with a semantic categorization task in which participants were induced to associate different values - positive, negative, or neutral - to each of the categorization decisions. Although semantic priming effects were obtained even with negatively valued decisions, they were substantially enhanced with positively valued decisions, confirming the influence of a decision bias induced presumptively by a post-lexical relatedness judgement.
Sex Differences in the Willingness to Betray and Switch Romantic Partners
Authors: Greitemeyer Tobias , Hengmith Simone , Fischer Peter
Published: February 2006

The present study examined sex differences in the willingness to accept a hypothetical sexual offer by different potential partners. 95 female and male participants were asked to imagine that their current partner was of moderate socioeconomic status, with a photo of moderate physical attractiveness. For each of four partners, depicted as either being of high or moderate socioeconomic status, with a photo of either high or moderate physical attractiveness, participants reported their willingness to date, to have sexual intercourse, and to leave their current partner for the new partner. Women and men reported a greater willingness to accept an offer by a potential partner who was highly, relative to moderately, attractive. Whereas women reported a greater willingness to accept an offer by a potential partner having a high, relative to moderate, socioeconomic status, men preferred the potential partner of medium socioeconomic status.
Acceptance as a Coping Reaction: Adaptive or not?
Authors: Nakamura Yuka Maya , Orth Ulrich
Published: February 2006

Acceptance as a coping reaction to unchangeable negative events has been discussed controversially. While some studies suggest it is adaptive, others report negative effects on mental health. We propose a distinction between two forms of acceptance reactions: active acceptance, which is associated with positive psychological outcomes, and resigning acceptance, which is associated with negative psychological outcomes. In this study, 534 individuals were surveyed with respect to several hypothetical situations. We tested the proposed acceptance model by confirmatory factor analysis, and examined the convergent and discriminant validity using personality and coping measures (Trier Personality Questionnaire, Bernese Bitterness Questionnaire, COPE). The results support the distinction between the two forms of acceptance reactions, and, in particular, that active acceptance is an adaptive reaction to unchangeable situations.
Entwicklung und Erprobung eines Interviews zur internationalen Personalauswahl
Authors: Volmer Judith , Staufenbiel Thomas
Published: February 2006

Zusammenfassung. Durch die zunehmende Globalisierung der Märkte steigt der Bedarf an adäquaten Auswahlinstrumenten für die internationale Personalauswahl. Ein Scheitern der Auslandsentsendung ist oftmals mit hohen materiellen und immateriellen Kosten verbunden. In der vorliegenden Studie wurde ein strukturiertes Auswahlinterview für den Auslandseinsatz entwickelt und erprobt. Das Interview wurde an einer Stichprobe deutscher Trainees (N = 66) validiert, die für die Dauer von 3 bis 7 Monaten ein Praktikum in den USA absolvierten. Es zeigen sich positive Zusammenhänge der Beurteilung im Interview sowohl mit Selbst- als auch mit Vorgesetzteneinschätzungen der Leistung im Praktikum. Darüber hinaus weist das Interview auch inkrementelle Validität auf, die sich darin zeigt, dass Varianz in beiden Leistungskriterien erklärt wird, die die Prädiktoren Alter, Geschlecht, Ausbildungserfolg und die bisherige Auslandserfahrung nicht erfassen.
In deutschsprachigen wissenschaftlichen Zeitschriften der Jahre 2004 und 2005 publizierte Forschungsbeiträge zur Arbeits- und Organisationspsychologie
Authors: Solga Marc , Blickle Gerhard
Published: February 2006

Zusammenfassung. Der vorliegende Beitrag gibt einen Überblick über Forschungsfelder und methodische Aspekte der arbeits- und organisationspsychologischen Forschungsbeiträge, die in den Jahren 2004 und 2005 in 14 deutschsprachigen wissenschaftlichen Zeitschriften publiziert wurden. Dabei zeigt sich eine Fokussierung der Arbeiten auf wenige Forschungsfelder, u. a. auf Eignungsdiagnostik/Personalauswahl, Belastung und Beanspruchung/Stress sowie organisationales Commitment und Extra-Rollenverhalten. Die arbeits- und organisationspsychologische Forschung findet ganz überwiegend im Felde statt. Es dominieren Analysen auf individualer Ebene; Gruppen oder Organisationen als Ganze stehen selten im Mittelpunkt der Analyse. Ursachen und Handlungsmöglichkeiten werden diskutiert.
Psychologische Erfolgsfaktoren bei Unternehmenszusammenschlüssen
Authors: Greitemeyer Tobias , Fischer Peter , Nürnberg Carola , Frey Dieter , Stahlberg Dagmar
Published: February 2006

Zusammenfassung. In der vorliegenden Studie wurde untersucht, inwieweit sich Mitarbeiter/innen (N = 155) einer übernehmenden und einer übernommenen Organisation (Übernehmerposition: Übernehmer vs. Übernommene) im Hinblick auf das emotionale Wohlbefinden, die Identifikation mit dem neu geschaffenen Unternehmen und die subjektiv erlebte Kontrolle über die anstehenden Änderungsprozesse unterscheiden. Es zeigte sich, dass Übernommene ein niedrigeres emotionales Wohlbefinden aufweisen, sich weniger mit der neuen Organisation identifizieren und die neu entstandene Situation als für sich weniger kontrollierbar erleben als Übernehmer. Lineare Strukturgleichungsmodelle ergaben ferner, dass die erlebte Kontrolle sowohl den Zusammenhang der Übernahmeposition mit emotionalem Befinden sowie der Übernahmeposition mit der organisationalen Identifikation (partiell) vermittelt. Diese Befunde legen für einen erfolgreich verlaufenden Fusionsprozess nahe, die betroffenen Mitarbeiter/innen einer Übernahme angemessen über die anstehenden Veränderungsprozesse und deren Ursachen zu informieren und ihnen die Möglichkeit zur Einflussnahme zu geben. Zukünftige Studien sollten entsprechende Interventionen entwickeln und deren Wirksamkeit evaluieren.
Coseismic ground deformation due to an intraplate earthquake using synthetic aperture radar interferometry: TheMw6.1 Killari, India, earthquake of 29 September 1993
Authors: Satyabala S. P.
Published: February 2006

TheMw6.1 Killari earthquake of 29 September 1993 occurred in central India, an intraplate area of low historical seismicity resulting in 11,000 fatalities and causing devastation within a 15 km by 16 km region near the epicenter (18.01°N, 76.56°E). This earthquake occurred on a nearly east‐west trending, ∼45° south dipping reverse fault and is one of the few intraplate earthquakes to produce a primary surface rupture. Interferometric analysis of ERS‐1 and ERS‐2 synthetic aperture radar data reveals ground deformation attributable to the Killari earthquake. Modeling the earthquake as a dislocation in an elastic half‐space points to reverse slip on a steep dipping fault though a planar fault does not fit the data well. Although severe temporal decorrelation effects prevent determination of all details of the ground deformation pattern, the analysis establishes that the coseismic deformation occurred over a region with dimensions of approximately 30 km by 20 km and suggests possible subsidence due to soil compaction within the meizoseismal area. Comparison of interferometric synthetic aperture radar measured to model‐predicted deformation indicates that the fault ruptured by the Killari earthquake increased in steepness from ∼45° near the ground surface to ∼70° at a depth of ∼6 km.
Charge separation in updraft of convective regions of thunderstorm
Authors: Bürgesser R. E. , Pereyra R. G. , Avila E. E.
Published: February 2006

The experiments described in this work are concerned with ice‐crystal graupel interactions. The influence of the impact velocity on charge separation during collisions is analyzed for three different velocities: 6, 8 and 11 m s−1. The ambient temperature was varied in the range −5 to −30°C and the effective water content between 0 to 2 g m−3. Charge diagrams of the sign of the electric current on the graupel as a function of the ambient temperature and the effective liquid water content for each velocity are presented. The results indicate that increasing the velocity leads to negative particle charging during riming at higher velocity and the implications of these findings to non‐severe thunderstorm are discussed.
Radar observations of daytime 150‐km echoes from outside the equatorial electrojet belt over Gadanki
Authors: Patra A. K. , Rao N. Venkateswara
Published: February 2006

We present systematic observations of daytime 150‐km echoes from Gadanki (13.5° N, 79.2° E, 6.3° dip latitude). The echoing region is confined to 142–162 km altitude and show forenoon descent and afternoon ascent displaying a ‘necklace shape’ quite similar to that of the equatorial 150‐km echoes. Signal‐to‐noise ratio, velocity and spectral width are as high as 13 dB above noise, −5 to 35 m s−1 and 2 to15 m s−1, respectively. The observed ‘necklace shape’ is first of its kind from Gadanki and the present observations have almost all characteristics of equatorial daytime 150‐km echoes. The Gadanki radar observations hence provide first experimental evidence on the occurrence of daytime 150‐km echoes outside the equatorial electrojet belt.
Statistical prediction of ENSO (Nino 3) using sub‐surface temperature data
Authors: Drosdowsky Wasyl
Published: February 2006

A number of statistical schemes for predicting the evolution of the El Niño–Southern Oscillation (ENSO) have been developed in recent years. These tend to show some skill out to 9 to 12 months from late in the southern autumn, but only limited skill for a few months from late summer through the so‐called “predictability barrier”. More recently statistical models utilizing sub–surface temperature data have shown improvement of skill over persistence through this autumn period. Empirical Orthogonal Function analysis is used to extract the dominant signals in the sub‐surface variability. The resulting statistical model shows similar skill to that obtained using other simple indices of sub‐surface temperature, such as the warm water volume or average depth of the 20°C isotherm, or from coupled ocean – atmosphere models. These statistical models can therefore be used as a more stringent benchmark against which the complex coupled dynamical models are assessed.
Evidence of a deep slow event before the Mw 6.6 Tottori earthquake using shear wave splitting measurements
Authors: Volti Theodora , Kaneda Yoshiyuki
Published: February 2006

Shear‐wave splitting (SWS) data, based on observations nine months before and three months after the 6th October 2000 Tottori earthquake (Chugoku, Japan) have been analyzed in order to assess the stress distribution in that area. Seismic stations are distributed within a radius of 50–100 km from the main shock epicenter. Fast polarizations agree with the regional E‐W compressive stress of the area. An apparent switch in polarizations from E‐W to N‐S occurs a few months before the main shock in the isolated area of deep foreshocks, whereas polarizations of aftershocks strike NW‐SE and rotate anticlockwise with time‐delays. We suggest that the switch of polarizations for the foreshocks is due to the occurrence of a slow slip event before the Tottori earthquake. Comparison with a tomographic study shows that foreshocks occurred in a ductile area and the “distributed shear” model for intraplate earthquakes explains best the mechanics of Tottori earthquake.
SAGE III solar ozone measurements: Initial results
Authors: Wang Hsiang‐Jui , Cunnold Derek M. , Trepte Chip , Thomason Larry W. , Zawodny Joseph M.
Published: February 2006

Results from two retrieval algorithms, “o3_aer” and “o3_mlr”, used for SAGE III solar occultation ozone measurements in the stratosphere and upper troposphere are compared. The main differences between these two retrieved (version 3.0) ozone are found at altitudes above 40 km and below 15 km. Compared to correlative measurements, the SAGE II type ozone retrievals (o3_aer) provide better precisions above 40 km and do not induce artificial hemispheric differences in upper stratospheric ozone. The multiple linear regression technique (o3_mlr), however, can yield slightly more accurate ozone (by a few percent) in the lower stratosphere and upper troposphere. By using SAGE III (version 3.0) ozone from both algorithms and in their preferred regions, the agreement between SAGE III and correlative measurements is shown to be ∼5% down to 17 km. Below 17 km SAGE III ozone values are systematically higher, by 10% at 13 km, and a small hemispheric difference (a few percent) appears. Compared to SAGE III and HALOE, SAGE II ozone has the best accuracy in the lowest few kilometers of the stratosphere. Estimated precision in SAGE III ozone is about 5% or better between 20 and 40 km and ∼10% at 50 km. The precision below 20 km is difficult to evaluate because of limited coincidences between SAGE III and sondes. SAGE III ozone values are systematically slightly larger (2–3%) than those from SAGE II but the profile shapes are remarkably similar for altitudes above 15 km. There is no evidence of any relative drift or time dependent differences between these two instruments for altitudes above 15–20 km.
Crustal deformation and the seismic cycle across the Kodiak Islands, Alaska
Authors: Sauber Jeanne , Carver Gary , Cohen Steven , King Robert
Published: February 2006

The Kodiak Islands are located ∼120 to 250 km from the Alaska‐Aleutian Trench and are within the southern extent of the 1964 Prince William Sound (Mw = 9.2) earthquake rupture and aftershock zone. Here we report new campaign GPS results (1993–2001) from northeastern Kodiak and reprocessed GPS results (1993–1997) from southwestern Kodiak. The rate and orientation of the horizontal velocities, relative to a fixed North America, range from 29.7 ± 1.7 mm/yr at N30.3°W ± 3.3°, located ∼120 km from the deepest point of the trench, to 8.0 ± 1.3 mm/yr at N62.4°W ± 9.3°, located ∼230 km from the trench. We evaluated alternate models of coseismic and interseismic slip to test the importance of the mechanisms that account for surface deformation rates. Near the Gulf of Alaska coastal region of Kodiak the horizontal velocity can be accounted for primarily by the viscoelastic response to plate motion and a locked main thrust zone (MTZ), downdip creep, and to a lesser extent, slip in the 1964 earthquake. Farther inland the dominant mechanisms that account for post‐1964 uplift rates are time‐dependent, downdip creep and a locked MTZ; for the horizontal velocity component, southwest translation of western Kodiak may be important as well. On the basis of the pre‐1964 and post‐1964 earthquake pattern of interseismic earthquakes, we suggest that between the occurrences of great earthquakes like the 1964 event, more moderate to large earthquakes occur in the southwestern Kodiak region than near northeastern Kodiak.
Attenuation of acoustic waves in glacial ice and salt domes
Authors: Price P. B.
Published: February 2006

Two classes of natural solid media, glacial ice and salt domes, are under consideration as media in which to deploy instruments for detection of neutrinos with energy ≥1018 eV. Though insensitive to 1011 to 1016 eV neutrinos for which observatories (e.g., AMANDA and IceCube) that utilize optical Cherenkov radiation detectors are designed, radio and acoustic methods are suited for searches for the very low fluxes of neutrinos with energies >1017 eV. This is because owing to the very long attenuation lengths of radio and acoustic waves produced by interactions of such neutrinos in ice and salt, detection modules can be spaced at horizontal distances ∼1 km, in contrast to the 0.12 km distances between strings of IceCube modules. In this paper, I calculate the absorption and scattering coefficients as a function of frequency and grain size for acoustic waves in glacial ice and salt domes and show that experimental measurements on laboratory samples and in glacial ice and salt domes are consistent with theory. For South Pole ice with grain size ∼0.2 cm at depths ≤600 m, scattering lengths are calculated to be 2000 and 25 km at frequencies 10 and 30 kHz, respectively; for grain size ∼0.4 cm at 1500 m (the maximum depth to be instrumented acoustically), scattering lengths are calculated to be 250 and 3 km. These are within the range of frequencies where most of the energy of the acoustic wave is concentrated. The absorption length is calculated to be 9 ± 3 km at all frequencies above ∼100 Hz. For NaCl (rock salt) with grain size 0.75 cm, scattering lengths are calculated to be 120 and 1.4 km at 10 and 30 kHz, and absorption lengths are calculated to be 3 × 104 and 3300 km at 10 and 30 kHz. Existing measurements are consistent with theory. For ice, absorption is the limiting factor; for salt, scattering is the limiting factor. Both media would be suitable for detection of acoustic waves from ultrahigh‐energy neutrino interactions.
Geometrical properties of the potential energy of the soft-sphere binary mixture
Authors: Grigera Tomás S.
Published: February 2006

We report a detailed study of the stationary points (zero-force points) of the potential energy surface (PES) of a model structural glassformer. We compare stationary points found with two different algorithms (eigenvector following and square gradient minimization), and show that the mapping between instantaneous configuration and stationary points defined by those algorithms is as different as to strongly influence the instability index K versus temperature plot, which relevance in analyzing the liquid dynamics is thus questioned. On the other hand, the plot of K versus energy is much less sensitive to the algorithm employed, showing that the energy is the good variable to discuss geometric properties of the PES. We find new evidence of a geometric transition between a minima-dominated phase and a saddle-point-dominated one. We analyze the distances between instantaneous configurations and stationary points, and find that above the glass transition, the system is closer to saddle points than to minima.
Exact decoupling of the Dirac Hamiltonian. III. Molecular properties
Authors: Wolf Alexander , Reiher Markus
Published: February 2006

Recent advances in the theory of the infinite-order Douglas-Kroll-Hess (DKH) transformation of the Dirac Hamiltonian require a fresh and unified view on the calculation of atomic and molecular properties. It is carefully investigated how the four-component Dirac Hamiltonian in the presence of arbitrary electric and magnetic potentials is decoupled to two-component form. In order to cover the whole range of electromagnetic properties on the same footing, a consistent description within the DKH theory is presented. Subtle distinctions are needed between errors arising from any finite-order DKH scheme and effects due to oversimplified and thus approximate decoupling strategies for the Dirac operator, which will, though being numerically negligible in most cases, still be visible in the infinite-order limit of the two-component treatment. Special focus is given to the issue, whether the unitary DKH transformations to be applied to the Dirac Hamiltonian should depend on the property under investigation or not. It is explicitly shown that up to third order in the external potential the transformed property operator is independent of the chosen parametrization of the unitary transformations of the generalized DKH scheme. Since the standard DKH protocol covers the transformation of one-electron integrals only, the presentation is developed for one-electron properties for the sake of brevity. Nevertheless, all findings for the calculation of one-electron properties within a two-component framework presented here also hold for two-electron properties as well.
Pressure derivatives in the classical molecular-dynamics ensemble
Authors: Meier Karsten , Kabelac Stephan
Published: February 2006

The calculation of thermodynamic state variables, particularly derivatives of the pressure with respect to density and temperature, in conventional molecular-dynamics simulations is considered in the frame of the comprehensive treatment of the molecular-dynamics ensemble by Lustig [J. Chem. Phys. 100, 3048 (1994)]. This paper improves the work of Lustig in two aspects. In the first place, a general expression for the basic phase-space functions in the molecular-dynamics ensemble is derived, which takes into account that a mechanical quantity G is, in addition to the number of particles, the volume, the energy, and the total momentum of the system, a constant of motion. G is related to the initial position of the center of mass of the system. Secondly, the correct general expression for volume derivatives of the potential energy is derived. This latter result solves a problem reported by Lustig [J. Chem. Phys. 109, 8816 (1998)] and Meier [Computer Simulation and Interpretation of the Transport Coefficients of the Lennard-Jones Model Fluid (Shaker, Aachen, 2002)] and enables the correct calculation of the isentropic and isothermal compressibilities, the speed of sound, and, in principle, all higher pressure derivatives. The derived equations are verified by calculations of several state variables and pressure derivatives up to second order by molecular-dynamics simulations with 256 particles at two state points of the Lennard-Jones fluid in the gas and liquid regions. It is also found that it is impossible for systems of this size to calculate third- and higher-order pressure derivatives due to the limited accuracy of the algorithm employed to integrate the equations of motion.
Critical threshold of noise-induced energy transduction in molecular machinery system
Authors: Li Ya Ping , Li Qian Shu
Published: February 2006

Responses of energy transduction of molecular machinery to random perturbation were investigated at the conditions where the system stayed near the bifurcation point. It was found that noise-induced oscillation (NIO) could occur. But how far from bifurcation point could one get the admissible region of NIO? We proposed and demonstrated numerically that there existed a critical threshold of NIO for each fixed noise intensity. Furthermore, it was found that noise intensity was a key factor for the determination of critical threshold. Finally, the detailed bifurcation diagram depending on noise intensity was replotted.
Two-component relativistic density-functional calculations of the dimers of the halogens from bromine through element 117 using effective core potential and all-electron methods
Authors: Mitin Alexander V. , van Wüllen Christoph
Published: February 2006

A two-component quasirelativistic Hamiltonian based on spin-dependent effective core potentials is used to calculate ionization energies and electron affinities of the heavy halogen atom bromine through the superheavy element 117 (eka-astatine) as well as spectroscopic constants of the homonuclear dimers of these atoms. We describe a two-component Hartree-Fock and density-functional program that treats spin-orbit coupling self-consistently within the orbital optimization procedure. A comparison with results from high-order Douglas-Kroll calculations—for the superheavy systems also with zeroth-order regular approximation and four-component Dirac results—demonstrates the validity of the pseudopotential approximation. The density-functional (but not the Hartree-Fock) results show very satisfactory agreement with theoretical coupled cluster as well as experimental data where available, such that the theoretical results can serve as an estimate for the hitherto unknown properties of astatine, element 117, and their dimers.
Quantum optimal control of molecular isomerization in the presence of a competing dissociation channel
Authors: Artamonov Maxim , Ho Tak-San , Rabitz Herschel
Published: February 2006

The quantum optimal control of isomerization in the presence of a competing dissociation channel is simulated on a two-dimensional model. The control of isomerization of a hydrogen atom is achieved through vibrational transitions on the ground-state surface as well as with the aid of an excited-state surface. The effects of different competing dissociation channel configurations on the isomerization control are explored. Suppression of the competing dissociation dynamics during the isomerization control on the ground-state surface becomes easier with an increase in the spatial separation between the isomerization and dissociation regions and with a decrease in the dissociation channel width. Isomerization control first involving transfer of amplitude to an excited-state surface is less influenced by the dissociation channel configuration on the ground-state surface, even in cases where the excited-state surface allows for a moderate spreading of the excited wave packet.
A Monte Carlo simulation study of lipid bilayer formation on hydrophilic substrates from vesicle solutions
Authors: Zheng Zheming , Stroumpoulis Dimitrios , Parra Alejandro , Petzold Linda , Tirrell Matthew
Published: February 2006

A general lattice Monte Carlo model is used for simulating the formation of supported lipid bilayers (SLBs) from vesicle solutions. The model, based on a previously published paper, consists of adsorption, decomposition, and lateral diffusion steps, and is derived from fundamental physical interactions and mass transport principles. The Monte Carlo simulation results are fit to experimental data at different vesicle bulk concentrations. A sensitivity analysis reveals that the process strongly depends on the bulk concentration C0, adsorption rate constant K, and all vesicle radii parameters. A measure of “quality of coverage” is proposed. By this measure, the quality of the formed bilayers is found to increase with vesicle bulk concentration.
Large amplitude shock wave in a strongly coupled dusty plasma due to delayed charging
Authors: Ghosh Samiran
Published: February 2006

The effect of delayed charging on nonlinear characteristics of a large amplitude longitudinal dust acoustic wave in the “kinetic regime” of a strongly coupled dusty plasma described by the generalized hydrodynamic equation has been investigated. Numerical investigations reveal that delayed charging induced anomalous dissipation causes the generation of a large amplitude shock wave in a strongly coupled dusty plasma only for Mach numbers lying between a minimum and a maximum value. It is found that the shock can cause the state transition from a strongly coupled to a weakly coupled state. In the case of high dust flow velocity the shock height is higher than the case of low flow velocity in comparison with the ion thermal velocity.
Finding the radial parallel temperature profile in a non-neutral plasma using equilibrium calculations on experimental data
Authors: Hart Grant W. , Peterson Bryan G.
Published: February 2006

In 1992, Eggleston et al. [D. L. Eggleston et al., Phys. Fluids B 4, 3432 (1992)] reported on a technique for measuring the radial temperature profile in a pure-electron plasma confined in a Malmberg-Penning trap by partially dumping the plasma onto a charge collector at the end of the trap. For short plasmas and short confining rings, the assumptions in their paper are violated and a more general calculation is needed. This paper presents a variation of the standard equilibrium calculation to find the temperature profile of a pure-electron plasma. Eggleston’s shortcut “evaporation” temperature method is found to require a correction factor that can be calculated using methods described in this paper. For typical conditions, the evaporation method overstates the actual temperature by a factor ranging from 1.1 to 1.5 or more, depending on the plasma’s total charge and temperature and the geometry of the trap.
Effects of compressibility on the magneto-Rayleigh-Taylor instability in Z-pinch implosions with sheared axial flows
Authors: Zhang Yang , Ding Ning
Published: February 2006

A linear analysis of the ideal magnetohydrodynamic (MHD) stability of the compressible Z-pinch plasma with axial flow is presented. Comparing with results of incompressible models, compressibility can reduce the growth rate of the magneto-Rayleigh-Taylor (MRT)/Kelvin-Helmholtz (KH) instability and allow sheared axial flows to mitigate the MRT instability far more effectively. The effect of magnetic field, which cannot be detected in an incompressible model, is also investigated. The result indicates that the mitigation effect of magnetic field on the MRT instability becomes significant as the perturbation wave-number increases. Therefore, with the cooperation of sheared axial flow, magnetic field, and plasma compressibility, the stability of the Z-pinch plasma is improved remarkably. In addition, the analysis also suggests that in an early stage of the implosion, because the plasma temperature is relatively low, the compressible model is much more suitable than the incompressible one based on the framework of MHD theory.
Nonplanar dust-acoustic shock waves for two-temperature ions in dusty plasma with dissipative effects and transverse perturbations
Authors: Zhang Jie-fang , Wang Yue-yue
Published: February 2006

The dissipation caused by fluid viscosity is investigated for unmagnified dusty plasma with two-temperature ions in a spherical geometry. Analytical investigation shows that the propagation of a small-amplitude wave is governed by the spherical Kadomtsev-Petviashvili-Burgers equation. The shock wave solutions for dust-acoustic shock waves with two types of charged dust grains, that is, constant charged dust grains and adiabatic variable charged dust grains, are studied. The effects caused by dissipation and transverse perturbations are also discussed.
Three-dimensional nonlinear Schrödinger equation for dust-acoustic waves and its stability in magnetized dusty plasma with two-temperature nonthermal ions and dust charge variation
Authors: Zhang Jie-fang , Wang Yue-yue
Published: February 2006

The effect of two-temperature nonthermal ions and variable dust charge on small-amplitude nonlinear dust-acoustic waves (DAW) is investigated. By using the reductive perturbation technique, the three-dimensional nonlinear Schrödinger equation (3D-NLSE) is first derived. The modulational instability of DAW in the magnetized dusty plasma is investigated as well. Meanwhile, some new and important stability regions are given. The effect of the nonthermal parameter a is shown to play a significant role in the determination of the normalized dust charge. Further, setting this parameter to zero degenerates the system into one in the magnetized dusty plasma consisting of the isothermal ions.
A novel aspect of dust in plasma
Authors: Tsintsadze N. L. , Murtaza G. , Ehsan Z.
Published: February 2006

Nonlinear screening of the dust grains immersed in a homogenous fully ionized electron-ion plasma is investigated. Assuming conservation of entropy, an important relation is obtained between the maximum potential (and therefore the charge) of the dust grain and the temperature of the electrons. The Thomas-Fermi equation is derived for the potential of a dust grain in a nondegenerate plasma suggesting the existence of dust atom with a well defined atomic radius. Furthermore, based on the Born-Oppenheimer approximation, the notion of a dust-grain molecule is introduced in which the protons act like a kind of “glue” which binds two negatively charged dust grains together, and the motion of the grains have little influence on that binding force. Finally, considering the weak interaction between the proton clouds of two dust grains, an expression of exchange energy is obtained.
Two-dimensional relativistic Fokker-Planck model for core plasma heating in fast ignition targets
Authors: Yokota T. , Nakao Y. , Johzaki T. , Mima K.
Published: February 2006

One of the key issues in the fast ignition scheme is a clarification of the imploded dense core heating by laser-produced fast electrons. To investigate the core heating process, a two-dimensional relativistic Fokker-Planck code “RFP-2D” for fast electron behavior in dense core plasmas has been developed. Energy loss of fast electrons due to Coulomb interactions is treated through not only usual short-range binary collisions but also long-range binary collisions, including a collective shielding effect. After describing the physics model, an examination is made of the energy deposition of fast electrons injected into a highly compressed D-T cylindrical plasma. The relative importance of the long-range Coulomb interaction and the influence of a self-generated electromagnetic field on the energy deposition profile are demonstrated.
Nonlinear waves in nonplanar and nonuniform dusty plasmas
Authors: Xue Ju-Kui , Zhang Li-Ping
Published: February 2006

The nonlinear properties of the dust acoustic solitary wave and shock wave in inhomogeneous nonplanar dusty plasmas are considered theoretically and numerically. The effects of nonthermally distributed ions, nonadiabatic dust charge fluctuation, and the inhomogeneity caused by nonuniform equilibrium particle density, nonuniform equilibrium charging, and nonplanar geometry on waves are presented. When τch∕τd is small but finite, where τch is the charging time scale and τd is the hydrodynamical time scale, a variable coefficients nonplanar Korteweg–de Vries (KdV) Burgers equation governing the nonlinear waves is derived by the perturbation method. The analytical expressions for the evolution of soliton and shock wave (both oscillatory and monotone shock) are obtained and the theoretical results are confirmed by the numerical solution of the nonlinear wave equation.
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SQUID amplifier operating with high-Q resonant input load
Authors: Falferi Paolo , Bonaldi Michele , Cerdonio Massimo , Vinante Andrea , Mezzena Renato , Prodi Giovanni Andrea , Vitale Stefano
Published: February 2006

We have extended to ultracryogenic temperatures the complete noise characterization of a low-noise two-stage superconducting quantum interference device (SQUID) amplifier developed for resonant gravitational wave detectors. The additive current noise is evaluated from open input measurements. To evaluate the back action voltage noise, the SQUID is strongly coupled to a high-Q macroscopic electrical resonator operating at 11.7 kHz. From these measurements, we estimate a minimum noise temperature of 15μK, corresponding to 27 times the quantum-limited noise temperature. Implications of this result for the sensitivity of resonant gravitational wave detectors are briefly discussed.
Harmonic decomposition to describe the nonlinear evolution of stimulated Brillouin scattering
Authors: Hüller S. , Masson-Laborde P. E. , Pesme D. , Casanova M. , Detering F. , Maximov A.
Published: February 2006

An efficient method to describe the nonlinear evolution of stimulated Brillouin scattering (SBS) in long scale-length plasmas is presented in the limit of a fluid description. The method is based on the decomposition of the various functions characterizing the plasma into their long- and short-wavelength components. It makes it possible to describe self-consistently the interplay between the plasma hydrodynamics, stimulated Brillouin scattering, and the generation of harmonics of the excited ion acoustic wave (IAW). This description is benchmarked numerically in one and two spatial dimensions [one dimensional (1D), two dimensional (2D)], by comparing the numerical results obtained along this method with those provided by a numerical code in which the decomposition into separate spatial scales is not made. The decomposition method proves to be very efficient in terms of computing time, especially in 2D, and very reliable, even in the extreme case of undamped ion acoustic waves. A novel picture of the SBS nonlinear behavior arises, in which the IAW harmonics generation gives rise to local defects appearing in the density and velocity hydrodynamics profiles. Consequently, SBS develops in various spatial domains which seem to be decorrelated one from each other, so that the backscattered Brillouin light is the sum of various backscattered waves generated in several independent spatial domains. It follows that the SBS reflectivity is chaotic in time and the resulting time-averaged value is significantly reduced as compared to the case when the IAW harmonics generation and flow modification are ignored. From the results of extensive numerical simulations carried out in 1D and 2D, we are able to infer the SBS reflectivity scaling law as a function of the plasma parameters and laser intensity, in the limit where the kinetic effects are negligible. It appears that this scaling law can be derived in the limit where the IAW harmonics generation is modeled simply by a nonlinear frequency shift.
Template-free synthesis of conducting-polymer polypyrrole micro/nanostructures using electrochemistry
Authors: Gupta S.
Published: February 2006

Controlled synthesis of conducting-polymer polypyrrole microcontainers by electrogenerated H2 gas bubbles act as template from a surfactant cum electrolyte (2-naphthalene sulfonic acid; β-NSA) on a stainless steel working electrode, followed by the electrochemical polymerization of pyrrole around the micelles is reported. The films consist of round grains and cup/bowl-like structures, which became lantern-like with increasing cycles. Sodium chlorate (NaClO3) was used as a reference electrolyte. The bowl diameter and room temperature conductivity ranged 50–2000 nm and 1–50Scm−1, respectively. An analysis of these films was complemented with Raman spectroscopy to identify the oxidized PPy, polaron, and bipolarons.
Hydrogen-induced ferromagnetism in ZnCoO
Authors: Lee H.-J. , Park C. H. , Jeong S.-Y. , Yee K.-J. , Cho C. R. , Jung M.-H. , Chadi D. J.
Published: February 2006

We have investigated experimentally the effects of n-type impurities such as Al and H on the magnetic properties of ZnCoO. The carrier density changes slightly upon the introduction of hydrogen but increases significantly in the case of Al. A measurement of magnetic circular dichroism indicates that, of the two impurities, only H induces ferromagnetism in ZnCoO. Our experimental data suggest that, unlike Al, H plays an important role in the enhancement of ferromagnetic spin-spin interactions that goes much beyond a carrier-mediated effect.
Imaging of domain wall motion in small magnetic particles through near-field microscopy
Authors: Schoenmaker Jeroen , Domingues dos Santos Antonio , Souche Yves , Seabra Antonio Carlos , Sampaio Luiz C.
Published: February 2006

We report magneto-optical scanning near-field optical microscopy images for 4×4×0.08μm3 and 16×16×0.08μm3 low magnetic anisotropy Co70.4Fe4.6Si15B10 particles. Measuring magneto-optical differential susceptibility we acquired images of the domain wall movement driven by an applied magnetic field with a spatial resolution better than λ∕4. For the 4×4×0.08μm3 sized particle, a sequence of 27 magneto-optical differential susceptibility images reveals the evolution of the magnetic domain structure between positive and negative saturation fields passing through the four-domain flux-closure magnetization structure. On the 16×16×0.08μm3 particle, we studied the role of the oscillating driving field on the susceptibility distribution. Comparing the different magneto-optical differential susceptibility sequences, the role of the shape anisotropy on the field induced domain wall movement is evidenced. Micromagnetic simulations were used to provide a better understanding of the domain wall movement.
Single metal nanoparticle absorption spectroscopy and optical characterization
Authors: Muskens O. L. , Del Fatti N. , Vallée F. , Huntzinger J. R. , Billaud P. , Broyer M.
Published: February 2006

Optical absorption spectra of small single metal nanoparticles are measured using a far-field technique combining a spatial modulation microscope with a broadband light source. Quantitative determination of the spectral and polarization dependencies of the absorption cross section of individual gold nanoparticles permits precise determination of their geometrical properties in excellent agreement with transmission electron microscopy measurements.
ZnO quantum dots synthesized by a vapor phase transport process
Authors: Lu J. G. , Ye Z. Z. , Huang J. Y. , Zhu L. P. , Zhao B. H. , Wang Z. L. , Fujita Sz.
Published: February 2006

A vapor phase transport growth process has been developed to synthesize ZnO quantum dots (QDs) on Si substrates. The characteristics were investigated for as-prepared ZnO QDs without any additional treatment. The formation of ZnO QDs with 6 nm in height and 15 nm in diameter is confirmed by scanning electron microscope and atomic force microscopy. Room-temperature photoluminescence reveals that the as-prepared ZnO QDs exhibit a predominant ultraviolet emission at 3.32 eV while the low energy defect-related blue-green emission is significantly quenched. The band gap of ZnO QDs is determined to be 3.41 eV, which evidently indicates the quantum confinement effects.
Engineering periodic arrays of nanoscale twin boundaries in bulk YBa2Cu3O7−δ with RuO2 additions
Authors: Shlyk L. , Krabbes G. , Fuchs G. , Mickel C. , Rellinghaus B. , Nenkov K.
Published: February 2006

A periodic array of nano-scale twin boundaries (TBs) was formed inside melt-processed YBa2Cu3O7−δ with RuO2 additions. The arrangement of the regular TBs along c axis improves irreversibility line and critical current density. We found a characteristic kink at Bcr=2.75T on the c-axis irreversibility line, indicative of correlated disorder. The field tilt angle below which pinning by the TB is effective is found to be ∼40°. We have attempted to reconcile our data with the predictions of the Bose-glass model for correlated disorder.
Silicon nanomechanical resonators with a double-triangle cross section leading to an enhanced mass sensitivity
Authors: De Vlaminck I. , De Greve K. , Lagae L. , Borghs G.
Published: February 2006

We report on a silicon nanomechanical resonator fabricated with a double-triangle cross section, leading to an enhanced mass sensing capabilities. We analytically derive the dependence of the mass detection limit on, respectively, the moment of inertia and the cross section of a beam resonator. We conclude that our scaling compatible fabrication scheme can yield an enhancement of as much as 2.3 with regard to regular, rectangular resonators of the same size. We experimentally confirm the shape dependence of the resonant frequency and maximum drive energy, supporting our model for the mass detection limit.