bluuebunny/crossref_metadata_2025_split huggingface dataset:
Muscle‐fiber conduction velocity during concentric and eccentric actions on a flywheel exercise device
Authors: Pozzo Marco , Alkner Björn , Norrbrand Lena , Farina Dario , Tesch Per A. 
Published: May 2006

AbstractA gravity‐independent flywheel exercise device (FWED) has been proven effective as a countermeasure to loss of strength and muscle atrophy induced by simulated microgravity. This study assessed muscle‐fiber conduction velocity (CV) and surface EMG instantaneous mean power spectral frequency (iMNF) during brief bouts of fatiguing concentric (CON) and eccentric (ECC) exercise on a FWED in order to identify electromyographic (EMG) variables that can be used to provide objective indications of muscle status when exercising with a FWED. Multichannel surface EMG signals were recorded from vastus lateralis and medialis muscles of nine men during: (1) isometric, 60‐s action at 50% of maximum voluntary action (MVC); (2) two isometric, linearly increasing force ramps (0–100% MVC); and (3) dynamic CON/ECC coupled actions on the FWED. Muscle‐fiber CV and iMNF were computed over time during the three tasks. During ramps, CV, but not iMNF, increased with force (P < 0.001). Conduction velocity and iMNF decreased with the same normalized rate of change in constant‐force actions. During CON/ECC actions, the normalized rate of change over time was larger for CV than iMNF (P < 0.05). These results suggest that, during fatiguing, dynamic, variable‐force tasks, changes in CV cannot be indirectly inferred by EMG spectral analysis. This underlines the importance of measuring both CV and spectral variables for muscle assessment in dynamic tasks. Muscle Nerve, 2006
Role of perineal ultrasound in the evaluation of urinary stress incontinence and pelvic organ prolapse: A systematic review
Authors: Dalpiaz Orietta , Curti Pierpaolo 
Published: May 2006

AbstractAimsA review of the international literature on urogynecology was performed to focus on the actual role of perineal ultrasound. It is an increasingly used tool for the assessment of pelvic floor dysfunction and incontinence. In recent years ultrasound studies have predominated but there is little information on normal values and confusion on methodology and measurements. The aim of this study is to report the data available in the Literature about ultrasound as investigational evaluation helpful in diagnosing of urinary incontinence and urethral hypermobility, to document pelvic floor anatomy and to assess anatomic and functional changes after surgery.MethodsA MED‐LINE search was conducted using combinations of heading terms: perineal, ultrasound, pelvic floor, urinary incontinence, pelvic organ prolapse.ResultsUltrasound has become an indispensable diagnostic procedure in urogynecology. Perineal, introital, and endoanal ultrasound are the most recommended techniques and the results comprise qualitative and quantitative findings. These are important for determining the localization of the bladder neck and vesico‐urethral junction and also for pre‐ and postoperative comparisons, and moreover for clinical applications and scientific investigations.ConclusionsThere are as yet little data and there is a need to find in the near future more standard and objective parameters for the diagnosis of urinary incontinence. They will be obtained by means of more accurate analysis and comparison of the parameters, leading to a more clinically useful diagnostic test and assuring reliable and reproducible results. Neurourol. Urodynam. © 2006 Wiley‐Liss, Inc.
Nanostructured hydrogenated amorphous carbon films doped with nitrogen on p‐silicon
Authors: Somani Prakash R. , Yoshida Akihiko , Afre Rakesh A. , Adhikary Sunil , Soga T. , Umeno M. 
Published: May 2006

AbstractThe synthesis of nanostructured hydrogenated amorphous carbon (a‐C:H) films doped with nitrogen using microwave‐assisted surface wave plasma chemical vapour deposition on quartz and p‐silicon substrates is reported. By controlling the deposition parameters, the Tauc band gap has been varied from 2.4 to 1.75 eV. Field emission scanning electron microscopy observations indicate that the films are nano‐ structured and the particle size varies considerably depending on the deposition conditions. Nitrogen seems to be responsible for the formation of the nanostructure. X‐ray photoelectron spectroscopy studies with depth profiling indicate that nitrogen is not uniformly distributed in the bulk of the films and the films are observed to be rich in carbon near the p‐silicon substrate. Nitrogen concentration increases away from the substrate towards the top surface. Resistivity, visible Raman and nitrogen/carbon ratio studies indicate that a significant amount of sp3 carbon is present in the films and nitrogen seems to be a weak donor in the a‐C:H matrix. Weak photovoltaic action is observed in nitrogen‐doped a‐C:H/p‐silicon cells. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effect of heat treatment on various physical properties in Zr80Ni20 metallic glass
Authors: Kokanović I. 
Published: May 2006

AbstractThe effect of heat treatment on various physical properties in Zr80Ni20 metallic glass has been investigated by means of differential scanning calorimetry and electrical resistivity measurements. Experimental values for the crystallisation temperature and activation energy of the crystallisation processes were derived by studying these processes at different heating rates. The electrical resistivity of the annealed samples up to a temperature slightly above the first crystallization exotherm decreases with decreasing heating rates and increasing annealing temperatures. The temperature dependence of the electrical resistivity of the samples has been interpreted in terms of the weak localization of electrons and contribution by electron–phonon scattering. The contribution by electron–phonon scattering increases with increasing the fraction of crystalline phases in the glass matrix. The superconducting transition temperature, Tc, of the Zr80Ni20 metallic glass annealed at heating rates of 60 K/min and 10 K/min up to annealing temperatures below its second crystallisation exotherm decreases with decreasing heating rates and increasing annealing temperatures. The homogeneity of the annealed Zr80Ni20 metallic glass is discussed by using the superconducting transition width as a criterion. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Thermal analysis of GaN‐based laser diode package
Authors: Hwang W. J. , Lee T. H. , Nam O. H. , Kim H. K. , Kwak J. S. , Park Y. J. , Shin M. W. 
Published: May 2006

AbstractThis paper reports on the thermal behavior of GaN‐based laser diode (LD) package as functions of cool‐ing systems, die attaching materials, and chip loading conditions. Thermal resistance and junction tem‐perature was determined by electrical‐thermal transient method. Significant change of thermal resistance with input current was observed under natural cooling condition due to the sensitive change of heat trans‐fer coefficient (h ) with temperature. Employment of PbSn as a die attachment was more advantageous over Ag‐paste in thermal behavior of LD package. Compare the thermal resistance of LD packages epi‐down and epi‐up structures. The partial thermal resistance from junction to submount is 4.68 K/W for epi‐down structure, and 9.65 K/W to epi‐up structure. The results demonstrate that the total thermal resistance of LD package be controlled mainly by the packaging design rather than the chip structure itself. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Nitride‐based light emitting diodes with quaternary p‐AlInGaN surface layers
Authors: Kuo C. H. , Chang S. J. , Chi G. C. , Lam K. T. , Sun Y. S. 
Published: May 2006

AbstractWe have demonstrated bulk p‐AlInGaN layers and light emitting diodes (LEDs) with p‐AlInGaN surface layers by metalorganic chemical vapor deposition (MOCVD). It was found that surface of the LED with p‐AlInGaN layer was rough with a high density of hexagonal pits. Although the forward voltage of the LED with p‐AlInGaN layer was slightly larger, it was found that we can enhance the output power by 54% by using p‐AlInGaN surface layer. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Investigation of optimized ohmic contact of direct ITO layer with synchrotron radiation analysis
Authors: Ha Jun‐Seok , Jang Jun‐Ho , Joo Min‐Ho , Kim Tae‐Hyeong , Park Kyu‐Ho , Shin Hyun‐Joon , Lee Jeong‐Soo , Jung Jong‐Jae 
Published: May 2006

AbstractWith application of the current transport enhanced layer (CTEL) on the top of p‐type GaN, we optimized process conditions, which show the contact resistance of 1.43x10–3 Ω·cm2, using ITO contact layer that has advantages in the enhancement of light extraction efficiency. High‐resolution near edge X‐ray absorption spectroscopy was used to investigate the interface reaction between GaN / CTEL and ITO layers. Interstitial molecular N2 was directly observed by vibrationally resolved N'K‐edge absorption spectroscopy. It is suggested that GaN was chemically changed to gallium oxide (Ga2O3) and nitrogen molecule (N2) [2Ga‐N + 3/2 O2 => Ga2O3+N2] during annealing process, and this newly formed layer makes depletion width narrowing for the tunneling properties for the ohmic contact. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Modeling and experimental analysis of InGaN MOVPE in the Aixtron AIX 200/4 RF‐S horizontal reactor
Authors: Yakovlev E. V. , Talalaev R. A. , Martin R. W. , Jeynes C. , Peng N. , Deatcher C. J. , Watson I. M. 
Published: May 2006

AbstractA combined modeling and experimental analysis of InGaN deposition in the widely used single‐wafer Aixtron AIX 200/4 RF‐S reactor is presented. The main focus of the study is the effect of the deposition temperature on the layer composition. InGaN epilayers were grown at setpoint temperatures between 760 and 920 °C, keeping other process parameters constant. Epilayer compositions were analysed using strain‐independent methods. Results from the modeling generally match the experimental compositional data well, and thus are used to analyze factors affecting indium transport and incorporation efficiency. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Structural characterization of InN quantum dots grown by Metalorganic Vapour Phase Epitaxy
Authors: Lozano J. G. , González D. , Sánchez A. M. , Araújo D. , Ruffenach S. , Briot O. , García R. 
Published: May 2006

AbstractThe effect of a low temperature GaN capping layer on the structural properties of InN quantum dots is reported. InN quantum dots grown onto sapphire using GaN buffer, with and without low temperature GaN capping layer, have been investigated by atomic force microscopy and transmission electron microscopy. The analysis revealed hexagonal shape quantum dots in both samples. Moreover, the GaN capping layer gives rise to a reduction in the dots aspect ratio. Moiré fringe patterns, obtained in planar view geometry, were used to analyse the strain relaxation of the InN quantum dots. The moiré pattern measurements demonstrated that the uncapped InN quantum dot is almost fully relaxed. These results are related to the formation of a 60° misfit dislocation network in the InN/GaN interface. However, the capping layer not only generated a change of the aspect ratio, but also a decrease in the heterostructure plastic relaxation. The reason of this effect is discussed. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Carrier dynamics in site‐controlled Ga1–xInxN quantum dots
Authors: Jetter M. , Pérez‐Solórzano V. , Gröning A. , Gräbeldinger H. , Ubl M. , Schweizer H. 
Published: May 2006

AbstractSite‐controlled nanostructures were fabricated by deposition of GaInN on top of hexagonal GaN pyramids by selective metal organic vapor‐phase epitaxy. This allows us to control exactly the position of the emitting quantum dots, which is an essential requirement for functionalized single‐photon emitters. The nature of the growth process implies also the formation of quantum wells on the side‐walls of the pyramid and quantum wires at the edges, next to the quantum dot on the apex. The emission properties of these structures were investigated using low‐temperature time‐resolved spectroscopy. These measurements showed regions of different confinement with emission in the green spectral wavelength range. The analysis of the decay times confirms that the luminescence originates from regions with different dimensionality. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Comparison of high quality GaN‐based light‐emitting diodes grown on alumina‐rich spinel and sapphire substrates
Authors: Tinjod Frank , de Mierry Philippe , Lancefield David , Chenot Sébastien , Virey Eric , Stone‐Sundberg Jennifer L. , Kokta Milan R. , Pauwels Damien 
Published: May 2006

AbstractHigh quality GaN‐based light‐emitting diodes (LEDs) can be achieved on alumina‐rich spinel (MgAl6O10), a new substrate material with better thermal and lattice match to GaN than sapphire. As alumina‐rich spinel is chemically very close to sapphire (Al2O3), the GaN metal‐organic chemical vapour deposition (MOCVD) conditions developed for c‐plane sapphire have been successfully replicated on it. In this article, we report on the electroluminescence (EL) properties of GaN‐based LEDs grown by MOCVD simultaneously on Al2O3‐(0001) and MgAl6O10‐(111). Both devices exhibit a linear increase of the light output power versus current density, with a higher EL‐intensity and a narrower EL‐linewidth for the LEDs grown on alumina‐rich spinel. However, due to the lower thermal conductivity of spinel, these LEDs start suffering from device heating at lower current densities than on sapphire. Irreversible damage occurs for DC current densities of ∼0.9 kA/cm2 and at an estimated junction temperature of ∼325 °C. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
High temperature refractive indices of GaN
Authors: Liu C. , Stepanov S. , Gott A. , Shields P. A. , Zhirnov E. , Wang W. N. , Steimetz E. , Zettler J. T. 
Published: May 2006

AbstractUndoped GaN (u‐GaN) films were grown by low pressure metalorganic vapour phase epitaxy (LP‐MOVPE) on sapphire substrates. In situ optical monitoring was applied to the growth process either using a LayTec EpiR‐DA TT spectroscopic reflectometer or Filmetrics F30. Refractive indices of u‐GaN films at 1060 °C were obtained in a spectral range from 370‐900 nm. A peak at 412±5 nm in refractive index spectra was observed, which most likely corresponds to the band‐gap of hexagonal GaN at a temperature of 1060 °C. Refractive indices below this band‐gap are fitted well to the first‐order Sellmeier formula. As an example of the applications of the refractive indices, the effective film thicknesses of GaN during the resumption from 3 dimensional (3D) to 2 dimensional (2D) growth have been calculated from the spectra recorded by a LayTec system using the optical constants obtained. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Coupling of phonons with excitons bound to different donors and acceptors in hexagonal GaN
Authors: Korona K. P. , Wysmołek A. , Kuhl J. , Kamińska M. , Baranowski J. M. , Look D. C. , Park S. S. 
Published: May 2006

AbstractTime‐resolved measurements of GaN with different donors (oxygen or silicon) and acceptors (zinc or magnesium) showed pronounced bound exciton lines and their phonon replicas. The analysis included three phonon modes characteristic for the wurtzite (hexagonal) phase: A1(LO), E1(TO) and E2H. It was shown that relative amplitudes of replicas depended upon the chemical nature of the defects that the bind excitons. The replicas were stronger for acceptor‐ than for donor–related features. Huang‐Rhys factors S = 0.06 ± 0.02 and S = 0.025 ± 0.01, were found for the A0X and the D0X LO replicas, respectively. A significant difference in phonon coupling to silicon and oxygen donor bound excitons has been observed. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
High temperature characterization of Pt‐based Schottky diodes on AlGaN/GaN heterostructures
Authors: Pedrós J. , Cuerdo R. , Lossy R. , Chaturvedi N. , Würfl J. , Calle F. 
Published: May 2006

AbstractThe performance of Pt/(Ti)/Au Schottky contacts on AlGaN/GaN heterostructures up to 360 °C has been investigated by means of I‐V‐T measurements. A simultaneous increase of the effective barrier height and a decrease of the ideality factor with increasing temperature is observed. Barrier values of 1.05‐1.15 eV and a n‐values of 1.35‐1.55 are obtained above 300 °C. A reversible behaviour during the cooling is observed for the Pt/Ti/Au contacts, whereas a slight degradation is observed in the Pt/Au case. The insertion of an intermediate Ti layer is revealed to highly improve the thermal stability of the devices. The diode parameters are significantly enhanced throughout the whole thermal cycle when this intermediate layer is 10 nm thick. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Quantum confined Stark effect in vertically correlated GaN/AlN quantum dots
Authors: Łepkowski S.P. , Jurczak G. 
Published: May 2006

AbstractWe investigate Quantum Confined Stark Effect (QCSE) in vertically correlated wurtzite GaN/AlN QDs, having hexagonal pyramid‐shape. We show that the QCSE in these structures depends not only on the vertical dimensions, i.e., the height of the QDs and the thickness of the barriers, but also on their base diameter. We show that for typical wurtzite GaN/AlN QDs, having the base diameter of 19.5nm, drop of the electrostatic potential in the QD region slightly increases with increasing the width of barriers. Consequently, the band‐to‐band transition energies in the QDs decrease. Qualitatively similar but a factor of two stronger dependences is obtained for superlattices of QWs having the same vertical dimensions. The increase of the base diameter of the dots results in stronger dependences of both the electrostatic potential and the band‐to‐band transition energy on the thickness on barriers. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Morphological evaluation of epitaxial GaN grown on r ‐plane sapphire by metalorganic vapor‐phase epitaxy
Authors: Kusakabe K. , Ohkawa K. 
Published: May 2006

AbstractMorphological evaluation of epitaxial GaN films grown on r ‐plane sapphire substrates by atmospheric metalorganic vapor‐phase epitaxy was investigated. The surface frequently showed rough morphology when the GaN was grown at conventional epitaxial conditions. It was found, however, that the surface roughness was improved by using appropriate combinations of growth temperature and low‐temperature GaN buffer thickness. Thereby, a peak‐to‐valley value of the roughness was reduced from 4 μm to 0.8 μm. The rotation of crystallographic orientations was observed in the flattened GaN films. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The connectivity threshold for the min‐degree random graph process
Authors: Kang Mihyun , Koh Youngmee , Ree Sangwook , Łuczak Tomasz 
Published: May 2006

AbstractLet 𝒢n = {Gmin(n, M)}M≥0 denote a min‐degree random multigraph process in which Gmin(n, M + 1) is obtained from Gmin(n, M) by connecting a randomly chosen vertex of a minimum degree with another vertex of the multigraph. We study the probability that the random multigraph Gmin(n, M) is connected. © 2006 Wiley Periodicals, Inc. Random Struct. Alg., 2006
Low rank rational perturbations of linear symmetric eigenproblems
Authors: Mazurenko L. , Voss H. 
Published: May 2006

AbstractIn this paper we study low rank rational perturbations of linear symmetric eigenvalue problems which for example govern free vibrations of mechanical structures with elastically attached loads, or mechanical vibrations of fluid–solid structures. Embedding the underlying rational eigenproblem into a parameter dependent family of linear eigenproblems, and examining the limit behaviour of the eigenvalues as the parameter approaches a pole, we determine the number of eigenvalues of the rational problem between two consecutive poles.
Effect of an intravenous single dose of ketamine on postoperative pain in tonsillectomy patients
Authors: DA CONCEIÇÃO MARIO JOSE , BRUGGEMANN DA CONCEIÇÃO DIOGO , CARNEIRO LEÃO CYNTHIA 
Published: May 2006

SummaryBackground:  Tonsillectomy has a high incidence of postoperative pain. The aim of the present study was to determine whether the use of low‐dose IV ketamine, before the start of surgery or after the end of the operation, would lead to significantly improved pain control after tonsillectomy in pediatric patients.Methods:  Ninety children, 5–7 years old, scheduled for elective tonsillectomy were randomly assigned to one of three groups of 30 patients each; groups I, II and III. Patients in group I received no ketamine. Patients in group II received 0.5 mg·kg−1 of ketamine before the surgical start and for group III the same dose was given after the operation ended. Postoperative pain was scored by the Oucher scale. Systolic and diastolic pressures and heart rate were recorded perioperatively. Unwanted side effects were recorded by the ward staff personnel on a 24‐h study‐specific questionnaire. Statistical tests consisted of Student's t‐test, chi‐square and anova as appropriated.Results:  The number of patients complaining of pain was greater in group I compared with patients in groups II and III with a significative statistical difference (P < 0.05). The degree of postoperative pain was significantly higher in patients of group I compared with groups II and III (P < 0.05). Eight patients in group I needed rescue doses of morphine, three for group II and none for group III. In group I, three of eight patients required two doses of morphine during the first 249h postoperatively. No unwanted side effects were noted.Conclusions:  The use of a single small dose of ketamine in a pediatric population undergoing tonsillectomy could reduce the frequency or even avoid the use of rescue analgesia in the postoperative period independent of whether used before or after the surgical procedure.
‘Infrastructures of Responsibility’: the Moral Tasks of Institutions
Authors: WILLIAMS GARRATH 
Published: May 2006

abstract  The members of any functioning modern society live their lives amid complex networks of overlapping institutions. Apart from the major political institutions of law and government, however, much normative political theory seems to regard this institutional fabric as largely a pragmatic convenience. This paper contests this assumption by reflecting on how institutions both constrain and enable spheres of effective action and responsibility. In this way a society's institutional fabric constitutes, in Samuel Scheffler's phrase, an infrastructure of responsibility. The paper discusses three key normative aspects of this infrastructure. First, institutions define roles and rules, alongside forms of sanction and encouragement, so as to realise limited forms of practical, normative agreement. Second, institutions allocate and adjudicate distinct responsibilities. This creates separate spheres of initiative, ensuring responsibilities are fulfilled and providing for structured disagreement and change. Third, because we move through a plurality of institutions and associations, we experience varying responsibilities and forms of recognition. Individual identities thus depend on several different forms of recognition, and are well placed to resist totalising or fundamentalist temptations. In sum, the paper argues that a liberal institutional fabric provides essential moral stability, though not an undesirable fixity. By containing the fragility and dangers of individual moral judgment, our institutional fabric allows such judgment to play a valuable role in human affairs.