7,021 research outputs found

    Constraints on Weakly Mixed Sterile Neutrinos in the Light of SNO Salt Phase and 766.3 Ty KamLAND Data

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    The possibility of flavor transitions into sterile neutrinos (accompanying the dominant LMA transitions) in the solar boron neutrino flux has been examined in a scenario proposed by Hollanda and Smirnov to overcome some generic problems of the pure LMA scenario. It is found that the most recent SNO salt phase solar neutrino data and the KamLAND 766.3 Ty spectral data, allow for a significant sterile presence in the solar boron neutrino flux reaching the earth.Comment: 12 pages, 4 figure

    Ge growth on ion-irradiated Si self-affine fractal surfaces

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    We have carried out scanning tunneling microscopy experiments under ultrahigh vacuum condition to study the morphology of ultrathin Ge films eposited on pristine Si(100) and ion-irradiated Si(100) self-affine fractal surfaces. The pristine and the ion-irradiated Si(100) surface have roughness exponents of alpha=0.19+/-0.05 and alpha=0.82+/-0.04 respectively. These measurements were carried out on two halves of the same sample where only one half was ion-irradiated. Following deposition of a thin film of Ge (~6 A) the roughness exponents change to 0.11+/-0.04 and 0.99+/-0.06, respectively. Upon Ge deposition, while the roughness increases by more than an order of magnitude on the pristine surface, a smoothing is observed for the ion-irradiated surface. For the ion-irradiated surface the correlation length xi increases from 32 nm to 137 nm upon Ge deposition. Ge grows on Si surfaces in the Stranski-Krastanov or layer-plus-island mode where islands grow on a wetting layer of about three atomic layers. On the pristine surface the islands are predominantly of square or rectangular shape, while on the ion-irradiated surface the islands are nearly diamond shaped. Changes of adsorption behaviour of deposited atoms depending on the roughness exponent (or the fractal dimension) of the substrate surface are discussed.Comment: 5 pages, 2 figures and 1 tabl

    Dark Energy and the Statistical Study of the Observed Image Separations of the Multiply Imaged Systems in the CLASS Statistical Sample

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    The present day observations favour a universe which is flat, accelerated and composed of 1/3\sim 1/3 matter (baryonic + dark) and 2/3\sim 2/3 of a negative pressure component, usually referred to as dark energy or quintessence. The Cosmic Lens All Sky Survey (CLASS), the largest radio-selected galactic mass scale gravitational lens search project to date, has resulted in the largest sample suitable for statistical analyses. In the work presented here, we exploit observed image separations of the multiply imaged lensed radio sources in the sample. We use two different tests: (1) image separation distribution function n(Δθ)n(\Delta\theta) of the lensed radio sources and (2) {\dtheta}_{\mathrm{pred}} vs {\dtheta}_{\mathrm{obs}} as observational tools to constrain the cosmological parameters ww and \Om. The results are in concordance with the bounds imposed by other cosmological tests.Comment: 20 pages latex; Modified " Results and Discussion " section, new references adde

    Environmental Uncertainty, Business Strategy, and Financial Performance: An Empirical Study of the U.S. Lodging Industry

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    A key premise in the normative literature is that an appropriate business strategy will favorably align an organization with its environment (Andrews, 1971; Hofer & Schendel, 1978; Porter, 1980). It is argued that the strategy that will produce the best results is dependent on existing environmental circumstances (Miles & Snow, 1978). This study investigated the tenet that, for firms in the lodging industry, there exists an optimal pattern or ’’fit’’ between the environment and the firm’s business strategy that separates the more successful operations from the less successful ones. The findings of this study indicate that a match between the state of the environment facing an organization and its business strategy is required for high performance. The results obtained provide an invaluable planning and analysis tool for all levels of management involved in charting a firm’s future

    Fine-tuning and naturalness issues in the two-zero neutrino mass textures

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    In this paper we analyze the compatibility of two-zero neutrino Majorana textures with the recent experimental data. Differently from previous works, we use the experimental data to fix the values of the non-vanishing mass matrix entries and study in detail the correlations and degree of fine-tuning among them, which is also a measure of how naturally a given texture is able to describe all neutrino data. This information is then used to expand the textures in powers of the Cabibbo angle; extracting random O(1) coefficients, we show that only in few cases such textures reproduce the mixing parameters in their 3 sigma ranges.Comment: 13 pages, 14 figures. Version to appear in NP

    Applying Role Theory in Developing a Framework for the Management of Customer Interactions in Hospitality Businesses

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    The determinants of consumer satisfaction have long intrigued researchers and practitioners alike. Unfortunately, in the case of service businesses and, in particular, the situation of the actual customer service interaction, little information has been amassed. Rather, the bulk of current knowledge focusing on the service transaction has been accumulated in the domain of operational conformance to standards tied to mechanistic service procedures where the performance evidence is substantial. Thus, the nature and attributes of a positive service experience and the role the service person plays in that experience remains, for the most part, a mystery. This article is an attempt to add to the understanding of the service person’s role and its various dimensions relative to the service interaction. In order to bridge the gap between the provider of the service and the consumer of it, the service person’s instrumental role in consummating the transaction will be examined from a conceptual viewpoint adapted from a sociological perspective on role theory and human interaction, The focus of this effort will be in the application of a behavioral viewpoint to the management of service interactions in the context of hospitality businesses

    Spatial multi-criteria decision analysis to predict suitability for African swine fever endemicity in Africa

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    Background African swine fever (ASF) is endemic in several countries of Africa and may pose a risk to all pig producing areas on the continent. Official ASF reporting is often rare and there remains limited awareness of the continent-wide distribution of the disease. In the absence of accurate ASF outbreak data and few quantitative studies on the epidemiology of the disease in Africa, we used spatial multi-criteria decision analysis (MCDA) to derive predictions of the continental distribution of suitability for ASF persistence in domestic pig populations as part of sylvatic or domestic transmission cycles. In order to incorporate the uncertainty in the relative importance of different criteria in defining suitability, we modelled decisions within the MCDA framework using a stochastic approach. The predictive performance of suitability estimates was assessed via a partial ROC analysis using ASF outbreak data reported to the OIE since 2005. Results Outputs from the spatial MCDA indicate that large areas of sub-Saharan Africa may be suitable for ASF persistence as part of either domestic or sylvatic transmission cycles. Areas with high suitability for pig to pig transmission (‘domestic cycles’) were estimated to occur throughout sub-Saharan Africa, whilst areas with high suitability for introduction from wildlife reservoirs (‘sylvatic cycles’) were found predominantly in East, Central and Southern Africa. Based on average AUC ratios from the partial ROC analysis, the predictive ability of suitability estimates for domestic cycles alone was considerably higher than suitability estimates for sylvatic cycles alone, or domestic and sylvatic cycles in combination. Conclusions This study provides the first standardised estimates of the distribution of suitability for ASF transmission associated with domestic and sylvatic cycles in Africa. We provide further evidence for the utility of knowledge-driven risk mapping in animal health, particularly in data-sparse environments.</p

    Band Structure of the Fractional Quantum Hall Effect

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    The eigenstates of interacting electrons in the fractional quantum Hall phase typically form fairly well defined bands in the energy space. We show that the composite fermion theory gives insight into the origin of these bands and provides an accurate and complete microscopic description of the strongly correlated many-body states in the low-energy bands. Thus, somewhat like in Landau's fermi liquid theory, there is a one-to-one correspondence between the low energy Hilbert space of strongly interacting electrons in the fractinal quantum Hall regime and that of weakly interacting electrons in the integer quantum Hall regime.Comment: 10 page
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