bluuebunny/crossref_metadata_2025_split huggingface dataset:
Low Energy Ne Scattering Spectroscopy for Insulators, and Materials in the Electric/Magnetic Fields
Authors: Umezawa Kenji , Nakanishi Shigemitsu , Hayashi Hideki , Higashitsutsumi Hideaki , Nagasawa Hiroki , Narihiro Eisuke , Ogai Keiko 
Published: September 2011

ABSTRACTThis study describes a low-energy atom scattering system that was combined with a time-of-flight spectrometer for insulator surface structural analysis. We show one example. MgO(001) crystal was used to study the surface analysis technique and is illustrated here. Insulator surface structure is difficult to study because of the charging effects during electron or ion-beam bombardment. Nevertheless, structural analysis of insulator surfaces is very important in fundamental research as well as in technology fields.
Effect of Oxygen Pressure on the Initial Oxidation Behavior of Cu and Cu-Au Alloys
Authors: Luo Langli , Kang Yihong , Liu Zhenyu , Yang Judith C , Zhou Guangwen 
Published: September 2011

ABSTRACTA wide information gap exists between our present atomic-scale knowledge of metal oxidation derived from conventional ultrahigh vacuum (UHV) surface science experiments and the oxidation mechanisms obtained from the growth of bulk oxide thin films under technologically relevant realistic (or near-) atmospheric conditions. To bridge this pressure gap, we present an in-situ transmission electron microscopy (TEM) study of the initial oxidation stage of Cu(100) and Cu-Au(100) surfaces where the oxygen partial pressure varies from 5x10-4 to 150 Torr. For Cu(100), with increasing oxygen partial pressure (pO2), the nucleation density of the oxide islands increases and so does the growth rate of the oxide islands. As the pO2 continues to increase, a transition from epitaxial cube-on-cube Cu2O islands to randomly oriented oxide islands is observed. A kinetic model based on the classic heterogeneous nucleation theory is developed to explain the effect of oxygen partial pressure on the oxide orientation. It is shown that such a transition in the oxide nucleation orientation is related to the effect of oxygen pressure on the nucleation barrier and atom collision rate. The Cu-Au(111) alloy revealed the same oxygen pressure dependency of the oxide nucleation orientation as pure Cu oxidation.
Effect of Buffer Structure on the Performance of a-Si:H/a-Si:H Tandem Solar Cells
Authors: Hsu C.H. , Lee C.Y. , Cheng P.H. , Chuang C.K. , Tsai C.C. 
Published: September 2011

ABSTRACTThe study focuses on the influence of the hydrogenated amorphous silicon carbide (a-SiC:H) buffer layer in hydrogenated amorphous silicon (a-Si:H) single-junction and tandem thin-film solar cells. By increasing the undoped a-SiC:H buffer layer thickness from 6nm to 12nm, the JSC in single-junction cell was significantly improved, and the efficiency was increased by 4.5%. The buffer layer also effectively improves the efficiency of the a-Si:H/a-Si:H tandem cells by 7% as a result of the increase in open-circuit voltage (VOC) and short-circuit current (JSC). Although the bottom cell absorbs less short-wavelength photons, the wider-bandgap doped and buffer layers were still necessary for improving the cell efficiency. Presumably, this is because these wider-bandgap layers allow more photons to reach the bottom cell. Also, they can reduce interface recombination.
The Use of Ammonium Carbamate as a High Energy Density Thermal Energy Storage Material
Authors: Schmidt Joel E. , Dudis Douglas S. , Miller Douglas J. 
Published: September 2011

ABSTRACTPhase change materials (PCMs) often have higher specific energy storage capacities at elevated temperatures. Thermal management (TM) systems capable of handling high heat fluxes in the temperature range from 20–100°C are necessary but lacking. State of the art PCMs in this temperature range are usually paraffin waxes with energy densities on the order of a few hundred kJ/kg or ice slurries with energy densities of the same magnitude. However, for applications where system weight and size are limited, it is necessary to improve this energy density by at least an order of magnitude. The compound ammonium carbamate, [NH4][H2NCOO], is a solid formed from the reaction of ammonia and carbon dioxide which endothermically decomposes back to CO2 and NH3 in the temperature range 20-100°C with an enthalpy of decomposition of ∼2,000 kJ/kg. Various methods to use this material for TM of low-grade, high-flux heat have been evaluated including: bare powder, thermally conductive carbon foams, thermally conductive metal foams, hydrocarbon based slurries, and a slurry in ethylene glycol or propylene glycol. A slurry in glycol is a promising system medium for enhancing heat and mass transfer for TM. Progress on material and system characterization is reported.
Investigation on Phase Change Behaviors of Si-Sb-Te Alloy: The Effect of Tellurium Segregation
Authors: Zhou Xilin , Wu Liangcai , Song Zhitang , Rao Feng , Ren Kun , Cheng Yan , Liu Bo , Yao Dongning , Feng Songlin , Chen Bomy 
Published: September 2011

ABSTRACTIn this study, novel Si2Sb2Te6 phase change material is investigated in detail for the phase change memory application using transmission electron microscopy and X-ray photoelectron spectroscopy. The phenomenon that Te diffuses to the film surface during phase switching and successively evaporates out has been confirmed. The phase change memory cells employing Si2Sb2Te6 and Si3Sb2Te3 materials are fabricated and programmed. For the Si2Sb2Te6-based cell a data endurance of 5×105 cycles is achieved with a failure mode resembling reset stuck, which can be attributed to the migration of Tellurium during the operation cycles. It means that a thermally stable material system of SixSb2Te3 is preferred for the PCM applications.
Evidence and Characterization of Crystallographic Defect and Material Quality after SLIM-Cut Process
Authors: Masolin Alex , Vaes Jan , Dross Frederic , Martini Roberto , Rodriguez Amaia Pesquera , Poortmans Jef , Mertens Robert 
Published: September 2011

ABSTRACTThe SLIM-Cut process is a kerf-free wafering technique to obtain silicon substrates as thin as 50μm. The quality of the resulting material must be assessed to ensure that this innovative Si-foil approach does not jeopardize the potential efficiency of the final solar cell in terms of electronic activity, defect density and location. For that reason, we performed Microwave-Detected Photoconductance Decay (MW-PCD), Deep-Level Transient Spectroscopy (DLTS) and optical inspections after defect etching of the foils surface. Analyses indicate that SLIM-Cut generates crystallographic defects which create deep level traps that have a negative impact on the lifetime of the silicon foil. Nonetheless, a decrease of the thermal budget will lead to a reduction of plasticity and hence lower the amount of defects and increase the foil quality.
Optically Induced Sub-Wavelength Transient Apertures in Sb-Te Based Films
Authors: Simpson Robert E. , Fons Paul J. , Kolobov Alexander V. , Wang Xiomin , Tominaga Junji 
Published: September 2011

ABSTRACTThe origin of sub-diffraction-limit apertures in Sb-based thin films is discussed. Electromagnetic energy can be channeled by these apertures thus allowing near-field focussing- the Super-RENS effect. The aperture formation within Sb, Sb2Te3, Sb2Te, SbTe and Ge2Sb2Te5 is investigated by time resolved optical pump-probe techniques and found to occur without melting. Density functional calculations have shown that these materials exhibit a thresholdlike change in their optical properties below their melting temperatures. The threshold is shown to be a consequence of thermally induced misalignment of p-orbital bonds. It is the non-linearity of this process that leads to the formation of the sub-diffraction-limit apertures.
Electroluminescence Properties of Eu-doped GaN-based Light-emitting Diodes Grown by Organometallic Vapor Phase Epitaxy
Authors: Nishikawa Atsushi , Furukawa Naoki , Lee Dong-gun , Kawabata Kosuke , Matsuno Takanori , Terai Yoshikazu , Fujiwara Yasufumi 
Published: September 2011

ABSTRACTWe investigated the electroluminescence (EL) properties of Eu-doped GaN-based light-emitting diodes (LEDs) grown by organometallic vapor phase epitaxy (OMVPE). The thickness of the active layer was varied to increase the light output power. With increasing the active layer thickness, the light output power monotonically increased. The maximum light output power of 50 μW was obtained for an active layer thickness of 900 nm with an injected current of 20 mA, which is the highest value ever reported. The corresponding external quantum efficiency was 0.12%. The applied voltage for the LED operation also increased with the active layer thickness due to an increase in the resistance of the LED. Therefore, in terms of power efficiency, the optimized active layer thickness was around 600 nm. These results indicate that the optimization of the LED structure would effectively improve the luminescence properties.
Ultraviolet Light Emitting Devices Using AlGdN
Authors: Kita Takashi , Kitayama Shinya , Ishihara Tsuguo , Izumi Hirokazu , Chigi Yoshitaka , Nishimoto Tetsuro , Tanaka Hiroyuki , Kobayashi Mikihiro 
Published: September 2011

ABSTRACTWe developed ultra-violet field-emission devices using rare-earth nitrides of Al1-xGdxN grown by a reactive radio-frequency magnetron sputtering technique. The Al1-xGdxN phosphor film excited by high-energy electrons shows a resolution limited, narrow intra-orbital luminescence from Gd3+ ions at 318 nm. The devise characteristics depend on injected current and acceleration voltage, which were analyzed by considering multiple excitation process of injected high-energy electrons.
Accounting Choice and the Fair Value Option
Authors: Guthrie Katherine , Irving James H. , Sokolowsky Jan 
Published: September 2011

SYNOPSIS
Under the fair value option, SFAS No. 159, firms have full discretion over electing to report specified financial instruments at fair value on a contract-by-contract basis. Building on Henry's (2009) study of early adopting banks, this paper examines to what extent firms' election of instruments benefited their current or future earnings. Our sample comprises the constituents of the S&P 1500 Index for the first quarters of fiscal years 2007 and 2008. Expanding the sample across industries and over time allows us to obtain a more complete picture of the adoption of the fair value option. We identify 72 adopters, two-thirds of which are not commercial banks. We do not find evidence of systematic opportunistic election of the fair value option. In only a handful of cases—concentrated among early adopters with an earnings shortfall—did firms experience a significant improvement in current or future earnings that casts doubt on whether their adoption was keeping with the intent and spirit of the standard.
Data Availability: The list of adopters used in this paper is available from the authors upon request.
Was the Sarbanes-Oxley Act Good News for Corporate Bondholders?
Authors: DeFond Mark L. , Hung Mingyi , Carr Emre , Zhang Jieying 
Published: September 2011

SYNOPSIS
We investigate the impact of the Sarbanes-Oxley Act (SOX) on corporate bondholder value by examining the bond market reaction to news events leading up to the passage of SOX. The net impact of SOX on bondholder value is difficult to predict, and there are many reasons why it may be viewed as either good or bad news. Our primary analysis reveals a significant decline in average bondholder value around these events. In addition, cross-sectional tests find that the decline is significantly larger among riskier bonds and among bonds held by firms that are expected to experience the greatest changes under SOX. Thus, our findings are consistent with the bond market expecting the exogenously imposed changes under SOX to make bondholders worse off.
Logics for stable and unstable mereological relations
Authors: Nenchev Vladislav 
Published: September 2011

Abstract
In this paper we present logics about stable and unstable versions of several well-known relations from mereology: part-of, overlap and underlap. An intuitive semantics is given for the stable and unstable relations, describing them as dynamic counterparts of the base mereological relations. Stable relations are described as ones that always hold, while unstable relations hold sometimes. A set of first-order sentences is provided to serve as axioms for the stable and unstable relations, and representation theory is developed in similar fashion to Stone’s representation theory for distributive lattices.
First-order predicate logic and modal logic are presented with semantics based on structures with stable and unstable mereological relations. Completeness theorems for these logics are proved, as well as decidability in the case of the modal logic, hereditary undecidability in the case of the first-order logic, and NP-completeness for the satisfiability problem of the quantifier-free fragment of the first-order logic.
The annual glaciohydrology cycle in the ablation zone of the Greenland ice sheet: Part 1. Hydrology model
Authors: Colgan William , Rajaram Harihar , Anderson Robert , Steffen Konrad , Phillips Thomas , Joughin Ian , Jay Zwally H. , Abdalati Waleed 
Published: September 2011

AbstractWe apply a novel one-dimensional glacier hydrology model that calculates hydraulic head to the tidewater-terminating Sermeq Avannarleq flowline of the Greenland ice sheet. Within a plausible parameter space, the model achieves a quasi-steady-state annual cycle in which hydraulic head oscillates close to flotation throughout the ablation zone. Flotation is briefly achieved during the summer melt season along a ∼17 km stretch of the ∼50 km of flowline within the ablation zone. Beneath the majority of the flowline, subglacial conduit storage ‘closes’ (i.e. obtains minimum radius) during the winter and ‘opens’ (i.e. obtains maximum radius) during the summer. Along certain stretches of the flowline, the model predicts that subglacial conduit storage remains open throughout the year. A calculated mean glacier water residence time of ∼2.2 years implies that significant amounts of water are stored in the glacier throughout the year. We interpret this residence time as being indicative of the timescale over which the glacier hydrologic system is capable of adjusting to external surface meltwater forcings. Based on in situ ice velocity observations, we suggest that the summer speed-up event generally corresponds to conditions of increasing hydraulic head during inefficient subglacial drainage. Conversely, the slowdown during fall generally corresponds to conditions of decreasing hydraulic head during efficient subglacial drainage.
In situ quantification of supraglacial cryoconite morphodynamics using time-lapse imaging: an example from Svalbard
Authors: Irvine-Fynn Tristram D.L. , Bridge Jonathan W. , Hodson Andrew J. 
Published: September 2011

AbstractThere is growing recognition of the significance of biologically active supraglacial dust (cryoconite) for glacial mass balance and ecology. Nonetheless, the processes controlling the distribution, transport and fate of cryoconite particles in the glacial system remain somewhat poorly understood. Here, using a 216 hour time series of plot-scale (0.04 m2) images, we quantify the small-scale dynamics of cryoconite on Longyearbreen, Svalbard. We show significant fluctuations in the apparent cryoconite area and dispersion of cryoconite over the plot, within the 9 day period of observations. However, the net movement of cryoconite across the ice surface averaged only 5.3 mm d−1. High-resolution measurements of cryoconite granule motion showed constant, random motion but weak correlation with meteorological forcing factors and no directional trends for individual particle movement. The high-resolution time-series data suggest that there is no significant net transport of dispersed cryoconite material across glacier surfaces. The areal coverage and motion of particles within and between cryoconite holes appears to be a product of differential melting leading to changes in plot-scale microtopography, local meltwater flow dynamics and weather-dependent events. These subtle processes of cryoconite redistribution may be significant for supraglacial albedo and have bearing on the surface energy balance at the glacier scale.
Assessment of multispectral glacier mapping methods and derivation of glacier area changes, 1978–2002, in the central Southern Alps, New Zealand, from ASTER satellite data, field survey and existing inventory data
Authors: Gjermundsen E.F. , Mathieu R. , Kääb A. , Chinn T. , Fitzharris B. , Hagen J.O. 
Published: September 2011

AbstractWe have measured the glacier area changes in the central Southern Alps, New Zealand, between 1978 and 2002 and have compiled the 2002 glacier outlines using an image scene from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER). Three automated classification methods were tested: (1) band ratio, (2) normalized-difference snow index and (3) supervised classification. The results were compared with the glacier outlines photo-interpreted from the ASTER data, and were further validated using GPS-aided field mapping of selected test glaciers. The ASTER 3/4 band ratio provided the best results. However, all the classification methods failed to extract extensive debris-covered parts of the glaciers. Therefore, the photo-interpreted 2002 outlines were used when comparing with the existing 1978 glacier inventory derived from aerial photographs. Our results show a ∼17% reduction of glacier area, mainly driven by the retreat of the large valley glaciers. Despite the large climatic gradient from west to east, glaciers on both sides of the Main Divide lost similar percentages of area, except Franz Josef and Fox Glaciers which advanced. Smaller glaciers were found to have changed very little in the study period.
2001–2009 elevation and mass losses in the Larsen A and B embayments, Antarctic Peninsula
Authors: Shuman Christopher A. , Berthier Etienne , Scambos Ted A. 
Published: September 2011

AbstractWe investigate the elevation and mass-balance response of tributary glaciers following the loss of the Larsen A and B ice shelves, Antarctic Peninsula (in 1995 and 2002 respectively). Our study uses MODIS imagery to track ice extent, and ASTER and SPOT5 digital elevation models (DEMs) plus ATM and ICESat laser altimetry to track elevation changes, spanning the period 2001–09. The measured Larsen B tributary glaciers (Hektoria, Green, Evans, Punchbowl, Jorum and Crane) lost up to 160 m in elevation during 2001–06, and thinning continued into 2009. Elevation changes were small for the more southerly Flask and Leppard Glaciers, which are still constrained by a Larsen B ice shelf remnant. In the northern embayment, continued thinning of >3 m a−1 on Drygalski Glacier, 14 years after the Larsen A ice shelf disintegrated, suggests that mass losses for the exposed Larsen B tributaries will continue for years into the future. Grounded ice volume losses exceed 13 km3 for Crane Glacier and 30 km3 for the Hektoria–Green–Evans glaciers. The combined mean loss rate for 2001–06 is at least 11.2 Gt a−1. Our values differ significantly from published mass-budget-based estimates for these embayments, but are a reasonable fraction of GRACE-derived rates for the region (∼40 Gt a−1).
La peur de la pénalité chez le joueur de rugby : histoire et diffusion du sport
Authors: Collins Tony 
Published: September 2011

L'importance de la pénalité (penalty) dans le rugby à XV trouve son origine dans les classes moyennes anglaises qui conçurent ce sport à l'époque victorienne. Or, ses dirigeants anglais ne souhaitaient pas en général que le rugby se « diffuse » et la crainte de la pénalité, à la fois sur le terrain et en dehors, est devenue l'un de ses traits distinctifs. Cet article montre que le processus d'expansion d'un sport ne se réduit pas à une « diffusion » naturelle ou spontanée. Les décisions prises par ses premiers dirigeants concernant son développement jouent également un rôle essentiel.
Nation et narration dans la diffusion sportive : l'exemple des courses de chevaux dans l'Algérie coloniale
Authors: Dine Philip 
Published: September 2011

Les courses hippiques constituent la première pratique sportive moderne de l'Algérie coloniale (1830-1962). Des officiers français de cavalerie y ont encouragé la participation d'élites indigènes afin d'inculquer des valeurs censées être favorables au projet colonial. Ce texte propose une analyse du discours de deux réunions hippiques de septembre 1852 en vue d'établir les paramètres institutionnels et idéologiques du processus de la diffusion sportive sur le territoire colonisé.
Le théâtre des fumeurs de « crack ». Mise en scène émotionnelle et voilement/dévoilement de soi
Authors: Fernandez Fabrice 
Published: September 2011

À partir d'une enquête ethnographique dans le quartier de la Goutte-d'Or à Paris, cet article interroge le jeu des émotions durant les scènes collectives de consommation de crack. Derrière les apparences du discours irrationnel, la mise en scène des émotions et le voilement/dévoilement de soi participent à construire du sens à ces interactions « sous influence » à l'intérieur des squats précaires, réarticulant des expériences hétérogènes dans la continuité de parcours de vie.
Evaluation et mesure des politiques de diversité culturelle
Authors: Guerfel-Henda Sana , Broussillon George-Axelle 
Published: September 2011

Résumé La gestion des diversités notamment culturelles est devenue une nécessité pour les organisations, en raison des récentes évolutions sociétales (création de la Charte de la Diversité, de la HALDE, du Label diversité) et des avantages en termes de performance économique et d’innovation. Toutefois, la question de l’évaluation de ces politiques appliquée à la diversité culturelle reste complexe puisque qu’elle pose celle de la mesure de la diversité des « spécificités culturelles » ou ethno-raciales et celle de l’évaluation des discriminations raciales. Pour dépasser l’absence de catégorisations ethnoraciales et respecter le cadre législatif imposé par la CNIL, les entreprises évaluent leurs processus RH et leurs moyens d’action avec des instruments comme l’audit social, le Label diversité ou le testing. Ces évaluations qualitatives s’accompagnent parfois de démarches quantitatives, telles que les analyses de recrutements ou d’effectifs qui s’appuient sur le patronyme ou lieu de résidence. Bien qu’efficaces, ces outils restent controversés et ne sauraient être des fins en soi, puisqu’il s’agit d’évaluer plus largement le processus de changement de culture de l’entreprise en tant que telle.
Ontologie de la décision individuelle et neurosciences : enjeux méthodologiques et épistémologiques
Authors: Marchais-Roubelat Anne 
Published: September 2011

Résumé Les théories de la décision sont fondées sur le concept d’individu, unité décisionnelle abstraite, isolée et indivisible qui ne risque pas d’être trompée par ses sens. Les neurosciences n’interrogent pas la notion d’individu, et pourtant elles en contiennent la critique : leurs méthodes d’investigation font apparaître un être vivant, parcouru de processus décisionnels entrelacés qui non seulement ignorent la frontière entre l’individu et son environnement mais encore interagissent selon des temporalités multiples. Les recherches en management peuvent-elles s’approprier la conception vivante du décideur dont sont porteuses les neurosciences pour susciter l’émergence d’un paradigme décisionnel plus adapté à l’action ?
Choix méthodologiques en Sciences de Gestion : pourquoi tant de chiffres ?
Authors: Maurand-Valet Anne 
Published: September 2011

Résumé Nous nous sommes interrogés sur l’augmentation du degré de formalisation des méthodes de recherche en sciences de gestion. Les explications que nous avançons sont de deux types : des facteurs psychologiques (confiance suscitée par des résultats chiffrés et recherche de la généralisation), des facteurs sociologiques (crédibilité scientifique, facilité de communication des résultats et reconnaissance par les pairs).