934 research outputs found

    Numerical and experimental study of open-cell foams for the characterization of heat exchangers

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    A multiscale model of open-cell foams is developed for the characterization of heat exchangers. The model is applicable to a wide range of materials, cell sizes, and porosities. The microscopic geometry is based on a periodic model that is defined by the porosity and the specific surface area of the foam considered. The representative geometrical scales of the model are validated with microscope images and computed tomography scans. The outputs of the microscopic model are the coefficients of the parabolic pressure loss curve, the thermal conductivity, and the Nusselt number. These values are used as inputs of the macroscopic model that determines the thermal performance of a macroscopic system. The results given by the models are compared with experimental data obtained from the literature, and from an experimental setup built at CERN. It is concluded that the multiscale model provides accurate results in all open-cell foams considered

    Three-Dimensional Angle Assessment and Plaque Distribution Classification in Left Main Disease: Impact of Geometry on Outcome.

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    Bifurcation geometry and plaque distribution in a diseased left main artery (LM) have the potential to drive operators' decisions regarding treatment strategies, techniques, and material selection. The three-dimensional (3D) geometry of the LM bifurcation typically results in specific patterns of plaque distribution. Plaque distribution may, in turn, significantly affect the procedural and long-term clinical and angiographic outcomes of LM percutaneous coronary intervention. Each LM bifurcation must be treated according to its unique anatomic and pathologic characteristics. Novel classification schemes of plaque distribution and 3D assessment may be valuable aids to obtaining a working picture of the bifurcation geometry

    Planning, Nature and Ecosystem Services

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    This book collects the papers presented at INPUT aCAdemy 2019, a special edition of the INPUT Conference hosted by the Department of Civil and Environmental Engineering, and Architecture (DICAAR) of the University of Cagliari. INPUT aCAdemy Conference will focus on contemporary planning issues with particular attention to ecosystem services, green and blue infrastructure and governance and management of Natura 2000 sites and coastal marine areas. INPUT aCAdemy 2019 is organized within the GIREPAM Project (Integrated Management of Ecological Networks through Parks and Marine Areas), co-funded by the European Regional Development Fund (ERDF) in relation to the 2014-2020 Interreg Italy – France (Maritime) Programme. INPUT aCAdemy 2019 is supported by Società Italiana degli Urbanisti (SIU, the Italian Society of Spatial Planners), Istituto Nazionale di Urbanistica (INU, the Italian National Institute of Urban Planning), UrbIng Ricerca Scientifica (the Association of Spatial Planning Scholars of the Italian Schools of Engineering) and Ordine degli Ingegneri di Cagliari (OIC, Professional Association of Engineers of Cagliari).illustratorThis book collects the papers presented at INPUT aCAdemy 2019, a special edition of the INPUT Conference hosted by the Department of Civil and Environmental Engineering, and Architecture (DICAAR) of the University of Cagliari. INPUT aCAdemy Conference will focus on contemporary planning issues with particular attention to ecosystem services, green and blue infrastructure and governance and management of Natura 2000 sites and coastal marine areas. INPUT aCAdemy 2019 is organized within the GIREPAM Project (Integrated Management of Ecological Networks through Parks and Marine Areas), co-funded by the European Regional Development Fund (ERDF) in relation to the 2014-2020 Interreg Italy – France (Maritime) Programme. INPUT aCAdemy 2019 is supported by Società Italiana degli Urbanisti (SIU, the Italian Society of Spatial Planners), Istituto Nazionale di Urbanistica (INU, the Italian National Institute of Urban Planning), UrbIng Ricerca Scientifica (the Association of Spatial Planning Scholars of the Italian Schools of Engineering) and Ordine degli Ingegneri di Cagliari (OIC, Professional Association of Engineers of Cagliari)

    The prevalence of secondary neoplasms in acromegalic patients:possible preventive and/or protective role of metformin

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    Background Acromegaly is a rare disease due to chronic growth hormone (GH) excess and the consequent increase in insulin-like growth factor-1 (IGF-1) levels. Both GH and IGF-1 play a role in intermediate metabolism affecting glucose homeostasis. The association between hyperinsulinemia/impaired glucose tolerance and an increased risk of cancer has been clarified. Insulin has a mitogenic effect through its interaction with the IGF-1 receptor (IGF-1R) that also binds IGF-1. On the other hand, metformin, an anti-hyperglycemic drug that decreases serum levels of insulin and IGF-1, could have a protective role in the treatment of endocrine tumors. Methods A retrospective, observational, multicenter study in 197 acromegalic patients, receiving/not receiving metformin, was performed to assess whether the prevalence of neoplasms might be correlated with insulin resistance and could eventually be modified by metformin treatment. Results In general, the occurrence of secondary neoplasia among our patients was significantly (pV = 0.035) associated with a positive family history of malignancy and with disease duration; a trend towards significance was observed in patients aged > 50 years. Acromegalic subjects who had undergone surgery showed a lower probability of developing a malignant tumor, whereas a higher prevalence of malignancies was observed in obese patients. No significant statistical difference was found when comparing metformin-treated or -untreated subjects for the presence of a second tumor. More interestingly, a trend towards statistical significance (pV = 0.065) was demonstrated in the metformin-treated group for the onset of a benign neoplasm. Conclusion Metformin could act directly on tumor cell metabolism and may have an adjuvant role in benign lesion progression

    The AMS Star Tracker thermal qualification overview

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    Four different thermal-vacuum tests were performed on AMICA Star Tracker (AST) in the period March-July 2006 in the space simulator of the SERMS laboratory in TerniItaly. Each of these tests was designed to verify different AST camera design features. The Thermal Balance test was conceived to validate the thermo-elastic model of the instrument and the active and passive thermal control subsystems. The Thermal Vacuum Cycling test was conceived to validate the AST electronics operative and survival temperature limits under vacuum conditions. The worst hot and cold operative and survival limits of the lens and filters in the AST optical system were assessed by means of the "Sun in the lens" and Lens Cold tests

    Use of statins in lower extremity artery disease: a review

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    BACKGROUND: Lower extremity artery disease (LE-PAD) is one of the most common manifestations of atherosclerosis, particularly in elderly patients, and it is related to a high cardiovascular risk. DESCRIPTION: It is well established that statin therapy is characterized by crucial benefits on cardiovascular system by limiting atherosclerotic progression and reducing cardiovascular events and mortality. A growing body of evidence support efficacy of statins in LE-PAD due to the ability of both reducing cardiovascular risk and improving walking distance and, hence, quality of life. Consequently, statin therapy should be considered in all LE-PAD patients and new LDL-cholesterol targets should be reached. CONCLUSIONS: Our opinion is that statin therapy remains still underutilized or with inadequate dosage, so therapy of LE-PAD patients should be improved to obtain all the demonstrated benefits of statin

    Potential for Circular Autopoietic Economy in High River Po Valley

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    This Gigamap aims to describe and summarize a student work carried out during the semester course Open Systems Design at Politecnico di Torino. This is one of the outputs from an analysis of the High River Po Valley area in the Italian Piedmont (Southwest of Turin) and subsequently an in-depth study of the relationships and “flows” with certain “currencies” between some selected economic and public actors. The analysis was conducted through five economic sectors: nature & ecosystem services, tourism, mobility and infrastructure, local craft activities and agri-food. The investigation of the territorial economy was carried out by giving particular attention to the production sectors characteristic of the territory and examine their production lines. The holistic diagnosis has highlighted the existence of several problems related to the linearity of the production processes. Through the five types of system flows (material, CO2 emissions/energy, water, economic and social flows), we designed new opportunities, new activities and new potential companies, thinking circularly and systemically. The Gigamap will be presented to stakeholders in a public hearing and used to illustrate and incubate a more circular economy that is more resilient and more regenerative. Reading the map The reader can find in the first part an abstract with the aim of the Gigamap, the five topics for the investigation and actors’ selection, a timeline about important events and some peculiarities of the territory. In the middle, the territorial map of a suggested improved territorial economy based on circular flows: the 16 actors are localized on the territory with new circular flows “designed in” between them. The boxes describe connections for new circular opportunities, with flows explained under the territorial map—finally, some data about the territory and the three main outputs emerging from the new circular linkages
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