4,086 research outputs found

    Innesti creativi in spazi industriali

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    La declinazione “città creativa” assume un significato definito dal 2004,quando UNESCO, con il programma “Creative cities” dà vita ad un network di città che individuano nella creatività, un motore strategico dello sviluppo economico e della rigenerazione urbana sostenibile.116 città che,tramite cooperazione internazionale,si muovono intorno ad obiettivi comuni,collocando la creatività e le industrie culturali alla base del loro sviluppo locale. A partire dalla percezione di caratteri che emergono dalle scene/grafie urbane,dalla storia e dalla geografia dei quartieri;che si esprimono in memoria sociale,in relazioni,in processi di riqualificazione e che si concretizzano in scelte imprenditoriali a carattere culturale,si da vita ad una serie di attività dal basso,il cui consumo definisce la nascita di nuove economie urbane. Esse danno risposta a nuovi gusti e stili di vita ma,nascendo da caratteri intrinsechi alla città ,trovano in essa profondo radicamento. Il potere di questi “innesti creativi”,come restituzione al sistema-città,è elevato. Lì dove si manifesta un vuoto urbano,tale non per assenza di costruito ma per assenza di linfa,e perciò meglio definibile come un “interrotto urbano”,si crea terreno fertile per l'accensione della miccia creativa. In pirotecnica,la miccia è la parte del dispositivo che innesca il dispositivo stesso;concetto alla base del potere di questi “quartieri post-moderni” che rigenerandosi,rigenerano le città,risolvendone problemi che vanno dalla riqualificazione di aree spesso tutelate dei centri storici europei,al recupero di aree dismesse,alla più attuale rigenerazione di quartieri periferici in cui gli elementi pulsanti creativi divengono occasione per la città di riappropriarsi,attraverso azioni sullo spazio pubblico,della città stessa

    Support and power plant documentation for the gas turbine powered bus demonstration program

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    The operational experience obtained for the GT404-4 gas turbine engines in the intercity and intracity Bus Demonstration Programs is described for the period January 1980 through September 1981. Support for the engines and automatic transmissions involved in this program provided engineering and field service, spare parts and tools, training, and factory overhauls. the Greyhound (intercity) coaches accumulated 183,054 mi (294,595 km) and 5154 hr of total operation. The Baltimore Transit (intracity) coaches accumulated 40,567 mi (65,285 km) and 1840 hr of total operation. In service, the turbine powered Greyhound and Transit coaches achieved approximately 25% and 40% lower fuel mileage, respectively, than did the production diesel powered coaches. The gas turbine engine will require the advanced ceramic development currently being sponsored by the DOE and NASA to achieve fuel economy equivalent not only to that of today's diesel engines but also to the projected fuel economy of the advanced diesel engines of the 1990s. Sufficient experience was not achieved with the coaches prior to the start of service to identify and eliminate many of the problems associated with the startup of new equipment. Because of these problems, the mean miles between incident were unacceptably low. The future gas turbine system should be developed sufficiently to establish satisfactory durability prior to evaluation in revenue service. Commercialization of the gas turbine bus engine remains a viable goal for the future

    Evidence of a new low field cross-over in the vortex critical velocity of type-II superconducting thin films

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    We measure current-voltage characteristics as function of magnetic field and temperature in Nb strips of different thickness and width. The instability voltage of the flux flow state related to the vortex critical velocity v* is studied and compared with the Larkin-Ovchinnikov theory. Beside the usual power-law dependence v* ~ B^-1/2, in the low field range a new cross-over field, Bcr1, is observed below which v* decreases by further lowering the external magnetic field B. We ascribe this unexpected cross-over to vortex channeling due to a fan-like penetration of the applied magnetic field as confirmed by magneto-optic imaging. The observation of Bcr1 becomes a direct evidence of a general feature in type-II superconducting films at low fields, that is a channel-like vortex motion induced by the inhomogeneous magnetic state caused by the relatively strong pinning

    Analytical Modeling of a Novel High-\u3cem\u3eQ\u3c/em\u3e Disk Resonator for Liquid-Phase Applications

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    To overcome the detrimental effects of liquid environments on microelectromechanical systems resonator performance, the in-fluid vibration of a novel disk resonator supported by two electrothermally driven legs is investigated through analytical modeling and the effects of the system’s geometric/material parameters on the dynamic response are explored. The all-shear interaction device (ASID) is based on engaging the surrounding fluid primarily through shearing action. The theory comprises a continuous-system, multimodal model, and a single-degree-of-freedom model, the latter yielding simple formulas for the fundamental-mode resonant characteristics that often furnish excellent estimates to the results based on the more general model. Comparisons between theoretical predictions and previously published liquid-phase quality factor (Q) data (silicon devices in heptane) show that the theoretical results capture the observed trends and also give very good quantitative estimates, particularly for the highest Q devices. Moreover, the highest Q value measured in the earlier study (304) corresponded to a specimen whose disk radius-to-thickness ratio was 2.5, a value that compares well with the optimal value of 2.3 predicted by the present model. The insight furnished by the proposed theory is expected to lead to further improvements in ASID design to achieve unprecedented levels of performance for a wide variety of liquid-phase resonator applications

    Speed limit to the Abrikosov lattice in mesoscopic superconductors

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    We study the instability of the superconducting state in a mesoscopic geometry for the low pinning material Mo3_3Ge characterized by a large Ginzburg-Landau parameter. We observe that in the current driven switching to the normal state from a nonlinear region of the Abrikosov flux flow, the mean critical vortex velocity reaches a limiting maximum velocity as a function of the applied magnetic field. Based on time dependent Ginzburg-Landau simulations we argue that the observed behavior is due to the high velocity vortex dynamics confined on a mesoscopic scale. We build up a general phase diagram which includes all possible dynamic configurations of Abrikosov lattice in a mesoscopic superconductor.Comment: 7 pages, 6 figure

    The Baxter Q Operator of Critical Dense Polymers

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    We consider critical dense polymers L1,2{\cal L}_{1,2}, corresponding to a logarithmic conformal field theory with central charge c=2c=-2. An elegant decomposition of the Baxter QQ operator is obtained in terms of a finite number of lattice integrals of motion. All local, non local and dual non local involutive charges are introduced directly on the lattice and their continuum limit is found to agree with the expressions predicted by conformal field theory. A highly non trivial operator Ψ(ν)\Psi(\nu) is introduced on the lattice taking values in the Temperley Lieb Algebra. This Ψ\Psi function provides a lattice discretization of the analogous function introduced by Bazhanov, Lukyanov and Zamolodchikov. It is also observed how the eigenvalues of the QQ operator reproduce the well known spectral determinant for the harmonic oscillator in the continuum scaling limit.Comment: improved version, accepted for publishing on JSTA

    GDM-complicated pregnancies: focus on adipokines

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    Gestational diabetes mellitus (GDM) is a serious complication of pregnancy and is defined as a state of glucose intolerance that is first diagnosed and arises during gestation. Although the pathophysiology of GDM has not yet been thoroughly clarified, insulin resistance and pancreatic β-cell dysfunction are considered critical components of its etiopathogenesis. To sustain fetus growth and guarantee mother health, many significant changes in maternal metabolism are required in normal and high-risk pregnancy accompanied by potential complications. Adipokines, adipose tissue-derived hormones, are proteins with pleiotropic functions including a strong metabolic influence in physiological conditions and during pregnancy too. A growing number of studies suggest that various adipokines including adiponectin, leptin, visfatin, resistin and tumor necrosis factor α (TNF-α) are dysregulated in GDM and might have pathological significance and a prognostic value in this pregnancy disorder. In this review, we will focus on the current knowledge on the role that the aforementioned adipokines play in the development and progression of GDM.Gestational diabetes mellitus (GDM) is a serious complication of pregnancy and is defined as a state of glucose intolerance that is first diagnosed and arises during gestation. Although the pathophysiology of GDM has not yet been thoroughly clarified, insulin resistance and pancreatic β-cell dysfunction are considered critical components of its etiopathogenesis. To sustain fetus growth and guarantee mother health, many significant changes in maternal metabolism are required in normal and high-risk pregnancy accompanied by potential complications. Adipokines, adipose tissue-derived hormones, are proteins with pleiotropic functions including a strong metabolic influence in physiological conditions and during pregnancy too. A growing number of studies suggest that various adipokines including adiponectin, leptin, visfatin, resistin and tumor necrosis factor α (TNF-α) are dysregulated in GDM and might have pathological significance and a prognostic value in this pregnancy disorder. In this review, we will focus on the current knowledge on the role that the aforementioned adipokines play in the development and progression of GDM

    Dosimetric characterization of CVD diamonds irradiated with 62 MeV proton beams

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    Diamond is potentially a very suitable material for use as on-line radiation dosimeter. Recent advances in the synthesis of polycrystalline diamond by chemical vapor deposition (CVD) techniques have produced material with electronic properties suitable for dosimetry applications. In this work the possibility to use a segmented commercial CVD detector in the dosimetry of proton beams has been investigated. The response as function of dose, dose rate, the priming and the rise time have been investigated thoroughly. This study shows the suitability of CVD diamond for dosimetry of clinical 62 MeV proton beams. r 2005 Elsevier B.V. All rights reserved

    Evaluation of systematic review utilization in the development of OB-GYN randomized controlled trials

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    Introduction: The issue of research waste has been raised due to the fact that 85% of funding for biomedical research has been improperly utilized. A prominent issue is the frequency of randomized controlled trials (RCTs) being conducted without prior consultation of existing support, such as systematic reviews (SRs). Meticulous monitoring is necessary to ensure that clinical recommendations are being made with confidence in high-quality biomedical practices. The aim of this study was to survey Obstetric and Gynecology journals to analyze their published articles for citation of SR for justification of conducting the RCT.Methods: We conducted a search of PubMed for RCTs published between January 1, 2014 and December 31, 2017, in the top ten Obstetric and Gynecology journals. Each included study was evaluated to determine the number of SRs cited within the introduction, methods, and discussion sections. We further analyzed whether the SR was cited verbatim or indirectly, number of participants, type of intervention being studied, funding source, type of trial, and how the outcome was perceived.Results: Of the 720 articles from our initial search, 458 (63.61%) met inclusion criteria. Of the 458 included studies, 279 (60.92%) cited an SR in the introduction, 34 (7.42%) cited an SR in the methods, and 207 (45.2%) cited an SR in the discussion as justification for conducting the study.Conclusion: A large portion of the RCTs being published in clinical Obstetrics and Gynecology journals are not citing SRs as justification for conducting their studies, which may be leading to an increase in research waste
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