1,347 research outputs found

    Phase diagram of random lattice gases in the annealed limit

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    An analysis of the random lattice gas in the annealed limit is presented. The statistical mechanics of disordered lattice systems is briefly reviewed. For the case of the lattice gas with an arbitrary uniform interaction potential and random short-range interactions the annealed limit is discussed in detail. By identifying and extracting an entropy of mixing term, a correct physical expression for the pressure is explicitly given. As an application, the one-dimensional lattice gas with uniform long-range interactions and random short-range interactions satisfying a bimodal annealed probability distribution is discussed. The model is exactly solved and is shown to present interesting behavior in the presence of competition between interactions, such as the presence of three phase transitions at constant temperature and the occurrence of triple and quadruple points.Comment: Final version to be published in the Journal of Chemical Physic

    Barriers and critical sucess factors applying cleaner production : a survey with Brazilian specialists

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    Cleaner Production is an initiative seeking for achieving sustainable development goals. Yet, it has not been satisfactorily disseminated in Brazilian industries. The purpose of this article was identifying the barriers and critical success factors, considering both the external and internal Brazilian environment. A survey was conducted among the professionals involved with the subject of Cleaner Production in Brazil, reaching 185 respondents. Data was analyzed using the Principal Component Analysis. The results indicated that the main success factors concern the organization characteristics, and are related to culture, strategic planning and resources for the implementation of Cleaner Production. In the case of barriers, it can be highlighted the inadequate vision and culture of organizations, followed by the lack of support from the external environment. Contrary to other studies, economic aspects did not seem to be crucial in the opinion of respondents. When measures that can be taken for a more effective dissemination of CP in Brazil are approached, it can be perceived that a repositioning of the external environment (government, other companies, academia, and consumers) is necessary, acting as a strong incentive and support for applying CP

    Study of soils from two trenches opened in a slope of the Serra do Mar for the sliding analysis

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    The landslides are mass gravitational movements induced by gravitational force and by the action of water. This event is the most recurrent and the largest producer of damages in Brazil. The objective of this research was to characterize soils from two trenches opened in a slope ot the Serra do Mar susceptible to landslides. Soil samples were collected and submitted to the geotechnical and physicoqchemical tests, which followed the Brazilian standards. A micro aggregation of the soil from both trenches was found on the basis of the granulometry analysis performed with and without deflocculant26XXVI Congresso de Iniciação Científica Unicam

    Fractal analysis of weld defect patterns obtained by radiographic tests

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    This paper presents a fractal analysis of radiographic patterns obtained from specimens with three types of inserted welding defects: lack of fusion, lack of penetration, and porosity. The study focused on patterns of carbon steel beads from radiographs of the International Institute of Welding (IIW). The radiographs were scanned using a greyscale with 256 levels, and the fractal features of the surfaces constructed from the radiographic images were characterized by means of Hurst, detrended-fluctuation, and minimal-cover analyses. A Karhunen-Loeve transformation was then used to classify the curves obtained from the fractal analyses of the various images, and a study of the classification errors was performed. The obtained results indicate that fractal analyses can be an effective additional tool for pattern recognition of weld defects in radiographic tests.Comment: 7 pages, 2 figures. To appear AIP Conference Proceedings - QNDE 200

    Spinning Hexagons

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    We reduce the computation of three point function of three spinning operators with arbitrary polarizations to a statistical mechanics problem via the hexagon formalism. The central building block of these correlation functions is the hexagon partition function. We explore its analytic structure and use it to generate perturbative data for spinning three point functions. For certain polarizations and any coupling, we express the full asymptotic three point function in determinant form. With the integrability approach established we open the ground to study the large spin limit where dualities with null Wilson loops and integrable pentagons must appear.Comment: 40 pages, 14 figure

    Methodology for Seamless Supply Chain Planning

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    Today, enterprises are typically in a constant process of acquiring and updating its information technologies, however typically without an overall view of the global inter and intra enterprise’s system integration. Researchers have been proposing methodologies and platforms to assist such integration of applications and data. However, implementing new technologies in organizations is a difficult task, since its quality needs for architectures development are more exigent and critical than ever, due to the systems complexity, dimension and to the interoperability requirements to interact with third party applications and infrastructures. This paper proposes a methodology for seamless Supply Chain Planning (SCP), by using a domain reference ontology, data model representation standards, software components evaluation and interoperability checking processes. The methodology VALTE is used to assure that enterprises use tools for SCP compliant to semantics, represented in a common reference ontology, created by the MENTOR methodology. These two horizontal methodologies are vertically supported by interoperability checking processes, which assure an interoperable supply chain planning system
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