4,942 research outputs found

    Rare and charmless decays of b-hadrons at Tevatron

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    I report the most recent results from the CDF and DØ Collaborations on the search for rare-decay modes of the b-hadrons. The results involve the current best limit on B0 (s)→ μ+μ− and B0(s)→ e+μ− decay modes, further results in charmless decays are expected soon

    Manganese-56 coincidence-counting facility precisely measures neutron-source strength

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    Precise measurement of neutron-source strength is provided by a manganese 56 coincidence-counting facility using the manganese-bath technique. This facility combines nuclear instrumentation with coincidence-counting techniques to handle a wide variety of radioisotope-counting requirements

    The development of Integrated Real Time Control to optimise storm water management for the combined sewer system of Rome

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    Increasing urbanisation and intensification of human activities are common trends all over the world. The higher portion of impermeable urban surfaces often leads to well known effects on storm water runoff and its polluting potential for receiving waters. Despite the variety of structural solutions and management practices proposed to mitigate the operational and environmental impact of urban runoff, their application on existing drainage systems can often be either ineffective at a metropolitan scale or unfeasible for a densely urbanised territory. Among all the proposed alternatives, the real time control (RTC) of drainage systems is proving more and more promising to dynamically regulate the system capacity in response to intense rainfall. The combined sewer network of Rome, historically built with high-capacity pipes to collect storm water from both urban and natural catchments, holds significant potential for RTC of online storage and combined sewer overflows, to optimise the global drainage capacity and reduce the impact of discharges on local river quality. To assess the real benefits, the potential limits and the feasibility of such a system for the city sewers, a pilot study has been conducted on a 3,000 hectare sub-catchment. It involved the development of a fast-response hydrodynamic simulation tool for the sewer network, the definition and evaluation of RTC strategies and the implementation of an environmental integrated telemetry system. As described here, the study has highlighted significant margins for the optimisation of the global network capacity without any major interventions on the physical assets, as well as some critical issues to solve for a fully operational RTC application

    Sediment Transport in Sewers: The Cesarina Combined Sewer Network

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    The polluting effects of storm water runoff on the receiving waterbodies represent an increasingly relevant problem in developing urban areas. In combined sewer pipes, transiting flood waves cause the alternation of sediment erosion and deposition of the solid material transported by the flow. Combined sewer deposit, mainly generated as an effect of such phenomena during the dry weather period between two rain events, is generally a mix of sand and highly polluting materials. Accumulation of sediments along a combined sewer network is often the cause of dysfunctions in the drainage system itself and negative impacts on the quality of receiving waters, due to the resuspension and overflow of pollutants. Both aspects have been investigated for the combined sewer of Rome thanks to an experimental catchment of about 2800 ha in the Cesarina – S. Basilio area. Based on the simulations conducted, structural solutions were proposed and evaluated, aimed at reducing the operational and environmental problems related to sewer sediment. The results show noticeable margins for the optimisation of the whole sewer system and for the reduction of its environmental impact

    Intraluminal recanalization of long infrainguinal chronic total occlusions using the Crosser system

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    Purpose: To assess the safety and efficacy of a device for vibrational angioplasty in the percutaneous intraluminal recanalization of long infrainguinal chronic total occlusions (CTO). Technique: The Crosser CTO Recanalization System is a mechanical recanalization device that uses high-frequency vibrational energy to disrupt and channel through fibrocalcific plaque without harming the vessel wall, thus assisting in the recanalization of an occluded artery. In 12 diabetic patients (7 men; median age 71 years, range 58–80) with critical limb ischemia owing to long (median length 26 cm, range 21–32) infrainguinal CTOs resistant to conventional guidewire techniques, the Crosser CTO Recanalization System was successful in intraluminally crossing the occlusion in 9 (75%) patients in ,5 minutes (mean 4:03 minutes). The safety endpoint (distal lumen guidewire position with no vessel perforation or dissection) was achieved in all successful cases. Conclusion: In our preliminary experience, the Crosser CTO Recanalization Catheter decreased crossing time, was safe, and achieved a high rate of intraluminal recanalization of long infrainguinal CTOs. J Endovasc Ther. 2009;16:23–27 Key words: critical limb ischemia, chronic total occlusion, percutaneous interventions, infrainguinal occlusion, intraluminal recanalization, vibrational energ

    Feasibility of a storage ring for polar molecules in strong-field-seeking states

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    We show, through modeling and simulation, that it is feasible to construct a storage ring that will store dense bunches of strong-field-seeking polar molecules at 30 m/s (kinetic energy of 2K) and hold them, for several minutes, against losses due to defocusing, oscillations, and diffusion. The ring, 3 m in diameter, has straight sections that afford access to the stored molecules and a lattice structure that may be adapted for evaporative cooling. Simulation is done using a newly-developed code that tracks the particles, in time, through 400 turns; it accounts for longitudinal velocity changes as a function of external electric field, focusing and deflection nonlinearities, and the effects of gravity. An injector, decelerator, and source are included and intensities are calculated.Comment: 6 pages 5 figures, 3 table

    Current management of herpes zoster: The European view

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    The overall incidence of herpes zoster in Europe is approximately 3 per 1000 people per year and more than 10 per 1000 people per year in those aged >80 years. Post herpetic neuralgia (PHN) is a common debilitating complication of herpes zoster, particularly in patients aged >50 years, in persons with severe pain or rash at presentation, and in those with significant prodromal symptoms. Antiviral drugs can effectively control acute symptoms and, if used early enough in the course of the illness, can help prevent the development of PHN and other complications. However, despite this, many patients do not receive such treatment. The economic impact of zoster and PHN is largely underestimated in Europe. Furthermore, there is considerable variation throughout Europe in the management of herpes zoster. Use of antiviral therapy including the newer potent antiviral agents such as brivudin, which requires less frequent administration than acyclovir, is improving patient outcomes in some European countries. However, in many countries, patient awareness of herpes zoster and, as a result, overall antiviral use is low. Guidelines recommending the use of antiviral agents, particularly in patients at risk of developing PHN, are available but are not widely used. More needs to be done to educate the general public and increase awareness among primary healthcare providers of the benefits of timely and appropriate pharmacological therapy in patients with herpes zoster. © 2005 Adis Data Information BV. All rights reserved

    A criterion for optimal management of water distribution networks

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    The management of water supply systems is based on fundamental principles, set by international and national legislations; the general target for water utilities is to offer a reliable and effective service following efficiency criteria. In this context, losses in distribution networks are one of the main problems to tackle: their reduction implies a general decrease in operational costs and in the need for a limited resource such as water. Numerous solutions have been proposed to reduce non revenue water, from simple leak detection to structural interventions on distribution systems, based on new design criteria which favour district-based networks over redundant ones. The present work proposes a new procedure to restructure a water supply network starting from its hydraulic model, comparing different types of intervention and evaluating their feasibility, limits and effectiveness in terms of the global system efficiency, as measured by the infrastructure leakage index (ILI). The possibility to use excessive pressure in specific parts of a network for the production of electricity is also examined, as it offers an additional resource to improve the system performance. The procedure has been tested for the water network in the municipalities of Tarcento and Magnano in Riviera, near Udine in Italy. Thanks to a specific hydraulic model, simulations were performed to identify the optimal interventions on the system aimed at reducing water losses and improving performances and efficiency
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