bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optical properties of bismuth oxide thin films prepared by reactive d.c. magnetron sputtering onto p‐GaSe (Cu)
Authors: Leontie Liviu , Caraman M. , Evtodiev Igor , Cuculescu Elmira , Mija Ana 
Published: July 2008

AbstractBismuth oxide (Bi2O3) thin films with thickness in the range 20–160 nm have been deposited by d.c. reactive magnetron sputtering of Bi in an atmosphere Ar:O2 (1:1), onto single crystalline p‐GaSe (Cu) substrates. The optical constants, n and k, of oxide films have been determined from the analysis of the polarization ellipse of the reflected radiation from outer surface of Bi2O3/p‐GaSe structures. In the wavelength range 400–800 nm the refractive index of nanometric Bi2O3 films onto GaSe(Cu) decreases from 2.10 to 1.78 and it seen to increase at decreasing sample thickness.In order to determine the interaction mechanism between semiconducting oxide film and GaSe surface, the spectral characteristics of photocurrent through Bi2O3/p‐GaSe junction and optical absorption in the range 400–800 nm have been examined. As resulted from respective analyses, Bi2O3 film generates new valence bonds, which contribute to the increase in the density of localized states at Bi2O3/p‐GaSe (Cu) junction interface. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effect of substrate temperature on the photocatalytic activity of sputtered TiO2 thin film
Authors: Hossain M. F. , Biswas S. , Takahashi T. , Kubota Y. , Fujishima A. 
Published: July 2008

AbstractIn this investigation, transparent TiO2 films were deposited at various substrate temperatures: RT, 200 °C, 300 °C and 400 °C by DC reactive magnetron sputtering technique to study the photocatalytic activity by the measurement of decomposition of methanol under UV–visible irradiation. The decomposition efficiency of TiO2 film increases initially with the increase of substrate temperature to 200 °C, but it decreases for the higher substrate temperatures. The correlation between the photocatalytic activity and the crystallographic, optical and morphological properties of TiO2 thin films was investigated in detail. Results show that increase of substrate temperature enhances crystallinity but reduces surface roughness. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electrical and optical properties of copper‐based chalcogenide thin films deposited by pulsed laser deposition at room temperature: Toward p‐channel thin film transistor fabricable at room temperature
Authors: Hiramatsu Hidenori , Yanagi Hiroshi , Kamiya Toshio , Hirano Masahiro , Matsunami Noriaki , Shimizu Ken‐ichi , Hosono Hideo 
Published: July 2008

AbstractCopper‐based chalcogenide thin films deposited at room temperature were examined for exploring an active layer material for a p‐channel thin film transistor (TFT) fabricable at room temperature. The electrical conductivities of chalcopyrite and simple copper chalcogenide thin films were controlled by introducing hydrogen sulfide and oxygen gases, respectively, during the film deposition. However, no current modulation by gate bias was observed in fabricated TFTs. Optical absorption spectra showed intense subgap absorptions, and these subgap states are thought to pin the Fermi levels. Although these copper‐based chalcogenides did not work as TFT channels, we found that simple copper chalcogenides deposited under a high vacuum showed p‐type degenerate conduction with a high conductivity up to 7.3 × 103 S/cm and a reasonably large work function of ∼4.7 eV. These properties are rather favorable for a hole injection layer of flexible electronic devices and suggest a promising application as an anode layer in organic light emitting devices. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Influence of pulsed electrodeposition on stoichiometry and thermoelectric properties of bismuth telluride films
Authors: Diliberto S. , Richoux V. , Stein N. , Boulanger C. 
Published: July 2008

AbstractBismuth telluride films were synthesized using pulsed electrodeposition. Synthesis of films from electrolytes with different [Bi]/[Te] ratios evidenced that an increase of bismuth concentration in the electrolyte leads to a decrease of the tellurium percentage in the film. A more important study with the ratio [Bi]/[Te] = 2 was carried out in order to correlate pulse parameters and film compositions. A crystallographic study underlined a variation of grains orientation following to the stoichiometry. The comparison of thermoelectric properties of pulsed and direct electrodeposited films showed that pulsed electrodeposition improves the morphology and decreases the electrical resistivity of films. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Influence of treatment conditions on chalcopyrite films deposited at atmospheric pressure
Authors: Todorov T. , Oliveira L. , Carda J. , Escribano P. 
Published: July 2008

AbstractSpin‐coating technique was used to deposit precursor layers for chalcopyrite films of the series CuInX2 and Cu(In,Ga)X2 where X = S or Se or (S,Se). The influence of different parameters of the process, such as solution composition, air pre‐treatment and chalcogenation treatment is discussed with respect to film applicability in photovoltaic devices. Layer morphology, stochiometry and crystalline structure varied widely with the different compositions and treatments. Highly oriented CuInSe2 and Cu(In,Ga)Se2 films were obtained. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Evolution of CO2 permeation properties of LDPE/LLDPE films upon uni‐axial stretching
Authors: Laffin C. , Forristal P. D. , O'Kiely P. 
Published: July 2008

AbstractA range of LDPE/LLDPE films were manufactured by blown and cast extrusion, which were then uni‐axially stretched at regular intervals. The films were analysed to determine the change of diffusion, solubility and permeation coefficient, and the correlation between crystallinity and molecular orientation. It was found that films exhibited a decrease in permeation coefficient with increased uni‐axial stretch as a result in change in crystal type and higher molecular orientation, resulting in a decrease of diffusion and solubility coefficient. This paper shows how double yield phenomena present in the uni‐axial stretching of the LDPE/LLDPE films affect the permeation properties. Copyright © 2008 John Wiley & Sons, Ltd.
Effectiveness of modified atmosphere packaging in preserving a prepared ready‐to‐eat food
Authors: Lee Ki‐Eun , Kim Hae Jin , An Duck Soon , Lyu Eun Soon , Lee Dong Sun 
Published: July 2008

AbstractThe effectiveness of modified atmosphere packaging (MAP) was evaluated for a combination prepared food (Korean braised green peppers with dry anchovies). From a preliminary storage test of the ready‐to‐eat dish at 10°C, the aerobic bacterial count on the green peppers was selected as a primary quality index. The effect of MAP with different CO2 concentrations on the product quality at 10°C was also studied. MAP with a CO2 concentration of ≥30% extended the lag time and/or reduced the growth rate of bacteria. Finally, the effect of different storage temperatures (5, 10, 15 or 20°C) on the shelf life of the product was investigated. Mathematical modelling of bacterial growth curves under stretch‐wrap air packaging and MAP with 60% CO2/40% N2 showed that MAP increased the hypothetical minimum temperature in the square root model that describes the temperature dependence of the lag time and growth rate. MAP conditions of 60% CO2/40% N2 extended the shelf life at 10°C by 130% (to 18.4 days) relative to that achieved with stretch‐wrap air packaging (7.9 days) based on the time taken to reach the quality limit of an aerobic bacterial count of 105 CFU/g. The relative extension of shelf life achieved with MAP was greater at lower temperatures. Copyright © 2008 John Wiley & Sons, Ltd.
Estimating mass and momentum fluxes in a line of cumulonimbus using a single high‐resolution Doppler radar
Authors: Hogan Robin J. , Illingworth Anthony J. , Halladay Kate 
Published: July 2008

AbstractWe present a method to derive the vertical‐wind field at a scale of 1–2 km from a high‐resolution Doppler radar, by performing vertical scans in the plane of the mean wind and tracking turbulent features on a scale of several hundred metres in the radial‐velocity field between consecutive scans. The method is applied to a line of cumulonimbus clouds observed by the high‐resolution Chilbolton radar in southern England. The storm was not a squall line, since it was propagating parallel rather than perpendicular to its length. A sequence of scans was taken over an hour‐long period; from these scans we derive the u and w components of the wind. Updraughts of up to 15 m s−1 are found.From these observations, the mass flux of a ‘typical’ storm cell was estimated: over the 50 min lifetime of the cell, the total mass of air transported from the boundary layer to the upper troposphere was found to be around 50 megatonnes. The profile of hour‐averaged momentum flux against height was then calculated and compared to the vertical shear of the mean horizontal wind. It was found that above 4.5 km, the momentum flux was down‐gradient, with an equivalent eddy diffusivity of around 103 m2s−1. Below this height, however, the flux was counter‐gradient, with an equivalent eddy diffusivity of around − 103m2s−1. We propose a mechanism to explain this behaviour, involving the prevalence of precipitation cooling and descent on the downshear side of convergence lines.A synthesis of the major wind flows in the storm reveals that, despite superficial appearance, the storm did not fit the usual multi‐cell paradigm, in which gust fronts play a key roll in triggering new cells downwind. Rather, the convergence lines associated with the convection were more akin to warm frontal surfaces that remain tied to the base of each cell, new cells tending to form upwind of older cells. Copyright © 2008 Royal Meteorological Society
Electrospray tandem mass spectrometry of alendronate analogues: fingerprints for characterization of new potential prodrugs
Authors: Hardouin Julie , Guénin Erwann , Malosse Christian , Caron Michel , Lecouvey Marc 
Published: July 2008

Abstract1‐Hydroxymethylene‐1,1‐bisphosphonic acids (HMBPs) are important drugs for the treatment of a variety of bone diseases. Since these compounds have no chromophore, their detection is challenging and mass spectrometry (MS) appears to be an appropriate sensitive tool. Our work deals with the analysis by electrospray ionization tandem mass spectrometry (ESI‐MSn) of the well‐known nitrogen‐containing HMBP alendronate and of three analogues, considered as potential prodrugs. These four molecules share a common structure with different protecting groups on the phosphonic acid and on the amine functions. We describe the dissociation mechanisms of nitrogen‐containing HMBPs in positive ion mode and we compare, in negative ion mode, our results with literature data. In both modes, the dissociations are essentially losses of ROH, and of phosphorus‐containing species (HPO2, ROP(OH)2 and ROPO(OH)2), where R = H, C6H5, or CH3OC6H5. These fingerprints will be of great value for differentiating alendronate from its potential prodrugs in complex biological mixtures. Copyright © 2008 John Wiley & Sons, Ltd.
Resonance excitation and dynamic collision‐induced dissociation in quadrupole ion traps using higher‐order excitation frequencies
Authors: Laskay Ünige A. , Jackson Glen P. 
Published: July 2008

AbstractFragmentation of the pentapeptide leucine enkephalin (YGGFL) is accomplished via higher‐order resonances combined with simultaneous analysis of low‐mass product ions. Two methods of achieving excitation are explored: (1) 0.5 ms resonant excitation at the ω and at Ω‐ω secular frequencies of ion motion (where Ω is the radio‐frequency (rf) drive frequency) in a manner similar to both pulsed q collision‐induced dissociation (PQD) and high amplitude short time excitation (HASTE), and (2) 0.5 ms pulse of the ω or at Ω‐ω excitation frequencies when the secular frequency of the ions is quickly swept across resonance conditions (pulsed q dynamic CID, PqDCID). In both methods of excitation, the rf amplitude on the ring electrode is rapidly decreased after excitation, therefore enabling analysis of low‐mass product ions. Maximum fragmentation efficiencies of ∼20% can be obtained with pulsed CID with both regular and high‐order frequency excitation, while pulsed DCID offers maximum efficiencies of ∼12%. All the excitation methods studied offer increased internal energy depositions when compared to conventional CID, as measured by the a4/b4 product ion ratios of leucine enkephalin. These ratios were as high as 13:1 for pulsed CID and 8:1 for PqDCID. Successful mass analysis of the low‐mass ions is observed with both pulsed CID and PqDCID. The combined benefit of high internal energy deposition and wider dynamic mass range offers the possibility of increased sequence coverage and the identification of unique internal fragments or high‐energy product ions which may provide complementary information to biological applications of conventional CID. This is the first report on deliberate fragmentation of precursor ions at a higher‐order component of the ion secular frequency combined with a successful mass analysis of the low‐mass ions through pulsed CID and PqDCID. Copyright © 2008 John Wiley & Sons, Ltd.
Human Vilyuisk encephalitis
Authors: Lipton Howard L. 
Published: July 2008

AbstractFor more than a century, a type of human encephalomyelitis has been known to affect indigenous people in the Sakha Republic in the Vilyui River Valley in Russia. The clinical features, laboratory findings, neuropathology, epidemiology and search for a causative pathogen are reviewed. One of the agents (Vilyuisk human encephalitis virus; VHEV) implicated in Vilyuisk encephalitis, belongs to a separate clade of Theiler's murine encephalomyelitis virus (TMEV). The recent discovery of theiloviruses from humans and the complete sequence of the VHEV raise the possibility that Vilyuisk arose from human cases of Vilyuisk encephalitis as a human–TMEV recombinant virus. Copyright © 2008 John Wiley & Sons, Ltd.
Advanced semiconductor diagnosis by multidimensional electron‐beam‐induced current technique
Authors: Chen J. , Yuan X. , Sekiguchi T. 
Published: July 2008

AbstractWe present advanced semiconductor diagnosis by using electron‐beam‐induced current (EBIC) technique. By varying the parameters such as temperature, accelerating voltage (Vacc), bias voltage, and stressing time, it is possible to extend EBIC application from conventional defect characterization to advanced device diagnosis. As an electron beam can excite a certain volume even beneath the surface passive layer, EBIC can be effectively employed to diagnose complicated devices with hybrid structure. Three topics were selected to demonstrate EBIC applications. First, the recombination activities of grain boundaries and their interaction with Fe impurity in photovoltaic multicrystalline Si (mc‐Si) are clarified by temperature‐dependent EBIC. Second, the detection of dislocations between strained‐Si and SiGe virtual substrate are shown to overcome the limitation of depletion region. Third, the observation of leakage sites in high‐k gate dielectric is demonstrated for the characterization of advanced hybrid device structures. SCANNING 30: 347–353, 2008. © 2008 Wiley Periodicals, Inc.
Angioarchitecture of the ventral surface of the tongue from Wistar rats
Authors: Verli Flaviana Dornela , Marinho Sandra Aparecida , Rossi‐Schneider Tissiana Rachel , Yurgel Liliane Soares , de Souza Maria Antonieta Lopes 
Published: July 2008

AbstractThe goal of this study was to describe the angioarchitecture of the ventral surface of the tongue from Wistar rats using a vascular corrosion casting technique associated with scanning electron microscopy (SEM). Six Wistar rats were used for the vascular casting method with Mercox® resin. Following the resin polymerization, the tongue of each animal was dissected and corroded in a 5% sodium hydroxide solution. Once the corrosion and drying of the specimens were completed, the specimens were mounted on aluminum stubs, coated with carbon and gold and analyzed under SEM. The results showed that the ventral surface of the tongue presents simple, even and abundant vasculature constituted by a vascular plexus consisting of a superficial vascular network and by the ranine veins. The superficial vascular network, made up of the ascending and descending branches, presents as a loose network, with little morphological variation between the capillary loops. SCANNING 30: 414–418, 2008. © 2008 Wiley Periodicals, Inc.
Efficient broadcast key distribution with dynamic revocation
Authors: Batten Lynn , Yi Xun 
Published: July 2008

AbstractMany commercial applications of broadcast require that only those users who have paid for the service can retrieve broadcast information. This is usually implemented by distributing a broadcast key to the set of privileged users and then encrypting broadcast information with the key. The set of privileged users is dynamic because users may join or quit the service at various times. Current solutions for efficient broadcast key distribution are usually built on the Shamir secret sharing scheme and implemented with smart cards. All such solutions revoke a pre‐specified number of users only. In this paper, we propose for the first time a broadcast key distribution scheme with the capability of revoking any number of users. The scheme is efficient and can be implemented on Smart Cards with low power setting. Furthermore, it provides authentication of the broadcaster to the receiver, authentication of the receiver to the broadcaster, and authentication of the information sent, and allows traitor tracing. Security analysis shows that our scheme is secure against both passive and active attacks. Performance analysis demonstrates that it is more efficient than other schemes designed for similar purposes. Copyright © 2008 John Wiley & Sons, Ltd.
Evaluating assumptions of weighting class methods for partial response using a selection model
Authors: Smith Philip J. , Marsh Lawrence C. 
Published: July 2008

AbstractIn survey sampling, information about the prevalence of a health outcomeYfor a defined target population is frequently obtained using a two‐stage data collection process. In the first stage, households that have members of the target population are identified and socio‐demographic data that are believed to be associated withYare collected. At the end of the first stage of data collection, permission is requested to contact the member's health providers so that accurate information aboutYcan be obtained. When permission is obtained, a second phase of data collection is conducted in which those health providers are contacted andYis obtained. A ‘complete response’ results when data are obtained from both the first and the second phases of the survey. A ‘partial response’ results when data are collected from the first phase, butYis not obtained in the second phase. To adjust for selection bias in estimating the prevalence ofYcaused by partial responders' missingYvalues, potential differences between complete and partial responders are typically taken into account by using weighting class methods. These methods assume that missingYvalues are missing at random (MAR). This paper describes statistical tests for evaluating whether missing data are missing completely at random or MAR. Copyright © 2008 John Wiley & Sons, Ltd.
A nonparametric smoothing method for assessing GEE models with longitudinal binary data
Authors: Lin Kuo‐Chin , Chen Yi‐Ju , Shyr Yu 
Published: July 2008

AbstractStudies involving longitudinal binary responses are widely applied in the health and biomedical sciences research and frequently analyzed by generalized estimating equations (GEE) method. This article proposes an alternative goodness‐of‐fit test based on the nonparametric smoothing approach for assessing the adequacy of GEE fitted models, which can be regarded as an extension of the goodness‐of‐fit test of le Cessie and van Houwelingen (Biometrics 1991; 47:1267–1282). The expectation and approximate variance of the proposed test statistic are derived. The asymptotic distribution of the proposed test statistic in terms of a scaled chi‐squared distribution and the power performance of the proposed test are discussed by simulation studies. The testing procedure is demonstrated by two real data. Copyright © 2008 John Wiley & Sons, Ltd.
Empirical estimation of life expectancy from large clinical trials: Use of left‐truncated, right‐censored survival analysis methodology
Authors: Nelson Charlotte L. , Sun Jie L. , Tsiatis Anastasios A. , Mark Daniel B. 
Published: July 2008

AbstractIn the current era of ever‐increasing health care costs, economic analyses are an essential component in the comprehensive evaluation of new medical interventions. Cost‐effectiveness analysis (CEA)—the most common form of economic analysis used in medicine—aids policy‐makers in determining how to allocate finite health care dollars among possible alternative therapies. CEA relates the incremental benefits of a new technology to its incremental costs in a cost‐effectiveness (CE) ratio. Although the generally agreed‐upon standard of presentation for the CE ratio is the lifetime perspective (incremental lifetime cost to add one life year), this perspective presents an obvious challenge to the statistical analyst. Most large clinical trials collect limited follow‐up data, and yet their findings form the basis of therapeutic recommendations that often extend far beyond the limits of the empirical data. Although clinical practice guidelines do not yet require explicit modeling to examine the long‐term implications of their recommendations, health policy analyses routinely rely upon such extrapolations. This paper describes methods for using empirical patient‐level data to extrapolate survival in large clinical trials and cohorts beyond a limited follow‐up period in which most patients remain alive in order to estimate the entire survival distribution for a cohort of patients. We accomplish this task through a novel combination of models that estimate the hazard rate not only as a function of time but also as a function of patient age. Extrapolation of survival beyond a limited time frame is made possible by capitalizing on the extensive latitude of survival information available across the range of ages represented in the data. Variations in approach are presented, and issues arising in these analyses are discussed. The proposed methodology is developed, applied, and evaluated in both a large clinical trial cohort with 5‐year follow‐up on over 23 000 patients and a large observational database with long‐term follow‐up on over 4000 patients. Copyright © 2008 John Wiley & Sons, Ltd.