6,996 research outputs found

    Energy-sharing asymmetries in ionization by positron impact

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    The triply differential cross section of molecular hydrogen for ionization by 50 eV positrons has been determined, for the first time, for both the ejected electron in coincidence with the remnant ion and for the scattered projectile. Asymmetries in the energy sharing between the two light particles in the final state are observed, with the electron spectrum being shifted to significantly lower (and the scattered positron to correspondingly higher) energies than expected. A similar shape is observed in the case of the ejected electron spectrum from a helium target at the same excess energy

    Infinite impulse response modal filtering in visible adaptive optics

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    Diffraction limited resolution adaptive optics (AO) correction in visible wavelengths requires a high performance control. In this paper we investigate infinite impulse response filters that optimize the wavefront correction: we tested these algorithms through full numerical simulations of a single-conjugate AO system comprising an adaptive secondary mirror with 1127 actuators and a pyramid wavefront sensor (WFS). The actual practicability of the algorithms depends on both robustness and knowledge of the real system: errors in the system model may even worsen the performance. In particular we checked the robustness of the algorithms in different conditions, proving that the proposed method can reject both disturbance and calibration errors

    triz analysis for solving problem in the production of aluminium food containers

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    On a daily basis, the concrete problems with researching solutions deal with the psychological inertia, the tendency to think and follow the same known mental schemes. The current work shows how the TRIZ can develop new and effective project solutions thanks to the examination of different prospective and points of view. In particular, the authors want to retrieve the analysis and the solutions for an anomaly found in an industry that designs and builds moulds and equipment for the production of aluminum food containers

    A Model of Control Valve for Wagons Equipped by k-Blocks

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    Paper illustrates the key features of the control valve model of TrainDy, renewed to be compliant with wagons that equip composite brake blocks type k in their braking systems. TrainDy is an international software owned by UIC (The International Union of Railways) and used by major Railway Undertakings in Europe to perform computations of Longitudinal Train Dynamics. Composite brake blocks type k equips new or revamped freight trains in Europe and are used to reduce train noise caused by particles of friction material between wheel and rail. This topic is particularly relevant since a relevant part of freight traffic in Europe is performed during night and many railway lines are close to highly populated areas. Paper shows the validation of this new model against experimental test campaigns performed at bench and in real field and made available for the revision process of UIC CODE 421 for freight train interoperability

    Mechanical characterization of parts fabricated by additive manufacturing

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    The explosion in the numbers of industrial applications making use of additive manufacturing (AM) techniques requires the use of reliable experimental data and appropriate design methods in order to ensure the adequate performance and safety of newly designed AM components. This Special Issue represents a collection of both experimental end numerical studies, covering the two realms of metallic and polymeric materials. The Special Issue is completed by papers focused on design and optimization problems, and on repair as well as on cost issues related to the production of AM components, which provide useful guidelines for design engineers and researchers

    Applying Lean to Healthcare Delivery Processes - a Case-based Research

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    The purpose of this paper is to demonstrate that Lean principles and methodology should be applied on a regular basis to the entire process flow of healthcare delivery systems. With reference to an actual case-based research, this article demonstrates how patient flows can be successfully optimized if Lean is not limited to single processes/contexts only, and it is applied to achieve holistic process improvement of an entire system. The complexity of healthcare delivery systems requires inclusive investigation from various points of view. This is why case-study-based research has been used to investigate dynamic, experiential and complex processes and areas, such as the ones featured by this article. The methodological basis for this research has been a twelve-step optimization approach outlined by the authors during a previous successful Lean programme. This same approach has been applied to optimize patient flows in the emergency departments of four different hospitals in Northern Italy. The research has involved teams composed of medical, nursing, technical and administrative staff.The results outlined in the article suggest that inclusive application of Lean tools leads to effective process optimization and a better working environment, when in connection with a systematic and holistic optimization approach. Feedback from participants was obtained through a satisfaction survey and a project assessment; it reported enthusiastic project acceptance and good teamwork climate. Among the results of the research performed in the four hospitals, several measures have been effectively implemented to reduce the lead-time for patients from registration to discharge. At the same time, patient-staff ratio and quality of care have been either maintained or even improved. However, lack of a definite conclusive evaluation can be explained by the research project still being implemented.The value of this paper lies in demonstrating how Lean contributes to achieve better process performance and high staff satisfaction, when implemented within the whole supply chain of a healthcare delivery system on a regular basis

    Common features between neoplastic and preneoplastic lesions of the biliary tract and the pancreas

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    The bile duct system and pancreas show many similarities due to their anatomical proximity and common embryological origin. Consequently, preneoplastic and neoplastic lesions of the bile duct and pancreas share analogies in terms of molecular, histological and pathophysiological features. Intraepithelial neoplasms are reported in biliary tract, as biliary intraepithelial neoplasm (BilIN), and in pancreas, as pancreatic intraepithelial neoplasm (PanIN). Both can evolve to invasive carcinomas, respectively cholangiocarcinoma (CCA) and pancreatic ductal adenocarcinoma (PDAC). Intraductal papillary neoplasms arise in biliary tract and pancreas. Intraductal papillary neoplasm of the biliary tract (IPNB) share common histologic and phenotypic features such as pancreatobiliary, gastric, intestinal and oncocytic types, and biological behavior with the pancreatic counterpart, the intraductal papillary mucinous neoplasm of the pancreas (IPMN). All these neoplastic lesions exhibit similar immunohistochemical phenotypes, suggesting a common carcinogenic process. Indeed, CCA and PDAC display similar clinic-pathological features as growth pattern, poor response to conventional chemotherapy and radiotherapy and, as a consequence, an unfavorable prognosis. The objective of this review is to discuss similarities and differences between the neoplastic lesions of the pancreas and biliary tract with potential implications on a common origin from similar stem/progenitor cells

    Disaster Resilience Assessment of Building and Transportation System

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    The paper presents a new methodology to assist decision-makers in the management of critical events such as earthquakes evaluating the recovery time, and the resilience index of a building system that is a component of the physical infrastructure dimension of the PEOPLES Resilience framework. The interdependencies between building system and transportation network in term of accessibility are modeled. Finally, the methodology has been implemented in a software and has been applied in two case studies: (a) the old medieval center of L’Aquila town and (b) the Treasure Island in the San Francisco Bay area

    Seismic Analysis of Traditional Stone Rural Buildings: Case study of a one-storey building

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    Specific features of traditional rural buildings can influence the assessment of their seismic behaviour. When a change in intended use of traditional rural buildings is necessary, restoration work must comply with specific seismic norms and should preserve their original features. In this paper, a model for the seismic safety verification of masonry walls for inplane actions was applied to investigate the structural behaviour of one-storey stone-masonry traditional rural buildings, in relation to standards application and possible retrofitting interventions. The results showed that pier-panel collapse mechanisms and the simulation method of masonry spandrel behaviour are of importance and affect the need to provide for strengthening interventions
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