999 research outputs found

    Compensation in undoped and halogen doped CdTe crystals

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    A theoretical model is proposed which allows the calculation of the concentration of defects in pure and halogen compensated cadmium telluride grown by the THM method. All associations and ionization reactions are described in terms of the law of mass action. The ionization energies of the defects are taken from the energy level diagram established by taking into account the latest experimental data. The concentrations of the different defects calculated for chlorine doped material are in good agreement with that measured using a time of flight method

    ENSO impact on simulated South American hydro-climatology

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    The variability of the simulated hydro-climatology of the WaterGAP Global Hydrology Model (WGHM) is analysed. Main object of this study is the ENSO-driven variability of the water storage of South America. The horizontal model resolution amounts to 0.5 degree and it is forced with monthly climate variables for 1961-1995 of the Tyndall Centre Climate Research Unit dataset (CRU TS 2.0) as a representation of the observed climate state. Secondly, the model is also forced by the model output of a global circulation model, the ECHAM4-T42 GCM. This model itself is driven by observed monthly means of the global Sea Surface Temperatures (SST) and the sea ice coverage for the period of 1903 to 1994 (GISST). Thus, the climate model and the hydrological model represent a realistic simulated realisation of the hydro-climatologic state of the last century. Since four simulations of the ECHAM4 model with the same forcing, but with different initial conditions are carried out, an analysis of variance (ANOVA) gives an impression of the impact of the varying SST on the hydro-climatology, because the variance can be separated into a SST-explained and a model internal variability (noise). Also regional multivariate analyses, like Empirical Orthogonal Functions (EOF) and Canonical Correlation Analysis (CCA) provide information of the complex time-space variability. In particular the Amazon region and the South of Brazil are significantly influenced by the ENSO-variability, but also the Pacific coastal areas of Ecuador and Peru are affected. Additionally, different ENSO-indices, based on SST anomalies (e.g. NINO3.4, NINO1+2), and its influence on the South American hydro-climatology are analysed. Especially, the Pacific coast regions of Ecuador, Peru and Chile show a very different behaviour dependant on those indices

    New Records of Hyperiidea (Crustacea: Amphipoda) from the North Central Gulf of Mexico

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    Records of 54 species of amphipods of the suborder Hyperiidea from the Gulf of Mexico are presented. Forty-seven species are recorded from the Gulf for the first time. Previous records of occurrence in the Gulf of Mexico, Caribbean Sea, and associated North Atlantic waters are provided for each species

    New Records of Hyperiidea (Crustacea: Amphipoda) from the North Central Gulf of Mexico

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    Records of 54 species of amphipods of the suborder Hyperiidea from the Gulf of Mexico are presented. Forty-seven species are recorded from the Gulf for the first time. Previous records of occurrence in the Gulf of Mexico, Caribbean Sea, and associated North Atlantic waters are provided for each species

    SOLUBILITY LIMIT OF DOPANTS IN SILICON IRRADIATED BY RUBY LASER

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    The solubility of several dopants (Sb, Ga, Bi, In) in laser treated silicon has been investigated. The dopants were introduced by vacuum deposition followed by a ruby laser irradiation. Their solubility was determined by Rutherford backscattering spectrometry measurements in channeling and random conditions. In all cases a solubility limit Cmℓ higher than the equilibrium solubility was found and a simple correlation with the equilibrium distribution coefficient kO could be established : Cmℓ = 8.6 × 1021 k0.51O cm-3

    From the Queue to the Quality of Service Policy: A Middleware Implementation

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    The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-642-02481-8_61Quality of service policies in communications is one of the current trends in distributed systems based on middleware technology. To implement the QoS policies it is necessary to define some common parameters. The aim of the QoS policies is to optimize the user defined QoS parameters. This article describes how to obtain the common QoS parameters using message queues for the communications and control components of communication. The paper introduces the Queue-based Quality of Service Cycle concept for each middleware component. The QoS parameters are obtained directly from the queue parameters, and Quality of Service Policies controls directly the message queues to obtain the user-defined parameters values.The middleware architecture described in this article is a part of the coordinated project SIDIRELI: Distributed Systems with Limited Resources. Control Kernel and Coordination. Education and Science Department, Spanish Government. CICYT: MICINN: DPI2008-06737-C02-01/02.Poza-Lujan, J.; Posadas-YagĂŒe, J.; SimĂł Ten, JE. (2009). From the Queue to the Quality of Service Policy: A Middleware Implementation. En Distributed Computing, Artificial Intelligence, Bioinformatics, Soft Computing, and Ambient Assisted Living. Springer Verlag (Germany). 432-437. doi:10.1007/978-3-642-02481-8_61S432437Aurrecoechea, C., Campbell, A.T., Hauw, L.: A Survey of QoS Architectures. Multimedia Systems Journal, Special Issue on QoS Architecture 6(3), 138–151 (1998)OMG. Data Distribution Service for Real-Time Systems, v1.1. Document formal/2005-12-04 (December 2005)Botts, M., Percivall, G., Reed, C., Davidson, J.: OGCÂź. Sensor Web Enablement: Overview And High Level Architecture, OpenGIS Consortium Inc (2006)Poza, J.L., Posadas, J.I., SimĂł, J.E.: QoS-based middleware architecture for distributed control systems. In: International Symposium on Distributed Computing and Artificial Intelligence, Salamanca (2008)Vogel, A., Kerherve, B., von Bochmann, G., Gecsei, J.: Distributed Multi-media and QoS: A Survey 2(2), 10–19 (1995)Crawley, E., Nair, R., Rajagopalan, B.: RFC 2386: A Framework for QoS-based Routing in the Internet, pp. 1–37, XP002219363 (August 1998)ITU-T Recommendation E.800 (0894). Terms and Definitions Related to Quality of Service and Network Performance Including Dependability (1994)Stuck, B.W., Arthurs, E.: A Computer & Communications Network Performance Analysis Primer. Prentice Hall, Englewood Cliffs (1984)Jain, R.: The art of Computer Systems Performance Analysis. John Wiley & Sons Inc., New york (1991)Coulouris, G., Dollimore, J., Kindberg, T.: Distributed Systems. Concepts and Design, 3rd edn. Addison Wesley, Madrid (2001)Jung, J.-l.: Quality of Service in Telecommunications Part II: Translation of QoS Pa-rameters into ATM Performance Parameters in B-ISDN. IEEE Comm. Mag., pp. 112–117 (August 1996)Wohlstadter, E., Tai, S., Mikalsen, T., Rouvellou, I., Devanbu, P.: GlueQoS: Middleware to Sweeten Quality-of-Service Policy Interactions. In: ICSE, 26th International Conference on Software Engineering (ICSE 2004) (2004

    Reference values and clinical predictors of bone strength for HR-pQCT-based distal radius and tibia strength assessments in women and men.

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    Reference values for radius and tibia strength using multiple-stack high-resolution peripheral quantitative computed tomography (HR-pQCT) with homogenized finite element analysis are presented in order to derive critical values improving risk prediction models of osteoporosis. Gender and femoral neck areal bone mineral density (aBMD) were independent predictors of bone strength. INTRODUCTION The purpose was to obtain reference values for radius and tibia bone strength computed by using the homogenized finite element analysis (hFE) using multiple stacks with a HR-pQCT. METHODS Male and female healthy participants aged 20-39 years were recruited at the University Hospital of Bern. They underwent interview and clinical examination including hand grip, gait speed and DXA of the hip. The nondominant forearm and tibia were scanned with a double and a triple-stack protocol, respectively, using HR-pQCT (XCT II, SCANCO Medical AG). Bone strength was estimated by using the hFE analysis, and reference values were calculated using quantile regression. Multivariable analyses were performed to identify clinical predictors of bone strength. RESULTS Overall, 46 women and 41 men were recruited with mean ages of 25.1 (sd 5.0) and 26.2 (sd 5.2) years. Sex-specific reference values for bone strength were established. Men had significantly higher strength for radius (mean (sd) 6640 (1800) N vs. 4110 (1200) N; p < 0.001) and tibia (18,200 (4220) N vs. 11,970 (3150) N; p < 0.001) than women. In the two multivariable regression models with and without total hip aBMD, the addition of neck hip aBMD significantly improved the model (p < 0.001). No clinical predictors of bone strength other than gender and aBMD were identified. CONCLUSION Reference values for radius and tibia strength using multiple HR-pQCT stacks with hFE analysis are presented and provide the basis to help refining accurate risk prediction models. Femoral neck aBMD and gender were significant predictors of bone strength

    PULSED ELECTRON BEAM ANNEALING OF As AND B IMPLANTED SILICON

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    p-type (100) silicon wafers have been implanted either by As or B ions at 20 and 200 keV energies and doses of 1016cm-2. Pulsed electron beam annealing has been performed with fluences of 1.1 and 1.4 J/cm2 using a mean electron energy of 15 keV. The pulse duration was 50 ns. The annealed layers have been investigated by Rutherford backscattering under random and channeling conditions and by S.I.M.S. profiling. Good crystal regrowth and high dopant activation occur in all cases except for the 200 keV Boron implant. Impurities redistribution is observed but no significant segregation effects appear. The experimental profiles are in good agreement with a diffusion model using a modified green function solution and taking into account dopant diffusion in liquid phase and the computed melt front location. The deduced diffusion coefficient are in the 5.10-5cm2/s range for boron and 2.10-4cm2/s range for arsenic

    What does your neighbourhood say about you? : a study of life expectancy in 1.3 million Swiss neighbourhoods

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    BACKGROUND: Switzerland had the highest life expectancy at 82.8 years among the Organisation for Economic Co-operation and Development (OECD) countries in 2011. Geographical variation of life expectancy and its relation to the socioeconomic position of neighbourhoods are, however, not well understood. METHODS: We analysed the Swiss National Cohort, which linked the 2000 census with mortality records 2000-2008 to estimate life expectancy across neighbourhoods. A neighbourhood index of socioeconomic position (SEP) based on the median rent, education and occupation of household heads and crowding was calculated for 1.3 million overlapping neighbourhoods of 50 households. We used skew-normal regression models, including the index and additionally marital status, education, nationality, religion and occupation to calculate crude and adjusted estimates of life expectancy at age 30 years. RESULTS: Based on over 4.5 million individuals and over 400,000 deaths, estimates of life expectancy at age 30 in neighbourhoods ranged from 46.9 to 54.2 years in men and from 53.5 to 57.2 years in women. The correlation between life expectancy and neighbourhood SEP was strong (r=0.95 in men and r=0.94 women, both p values &lt;0.0001). In a comparison of the lowest with the highest percentile of neighbourhood SEP, the crude difference in life expectancy from skew-normal regression was 4.5 years in men and 2.5 years in women. The corresponding adjusted differences were 2.8 and 1.9 years, respectively (all p values &lt;0.0001). CONCLUSIONS: Although life expectancy is high in Switzerland, there is substantial geographical variation and life expectancy is strongly associated with the social standing of neighbourhoods
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