1,017 research outputs found

    Beam diagnostics for charge and position measurements in ELI-NP GBS

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    The advanced source of Gamma-ray photons to be built in Bucharest (Romania), as part of the ELI-NP European Research Infrastructure, will generate photons by Compton back-scattering in the collision between a multi-bunch electron beam and a high intensity recirculated laser pulse. An S-Band photoinjector and the following C-band Linac at a maximum energy of 720MeV, under construction by an European consortium (EurogammaS) led by INFN, will operate at 100Hz repetition rate with trains of 32 electron bunches, separated by 16ns and a 250pC nominal charge. The different BPMs and current transformers used to measure transverse beam position and charge along the LINAC are described. Design criteria, production status and bench test results of the charge and position pickups are reported in the paper, together with the related data acquisition systems

    The European Union, borders and conflict transformation: the case of Cyprus

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    Much of the existing literature on the European Union (EU), conflict transformation and border dynamics has been premised on the assumption that the nature of the border determines EU intervention and the consequences that flow from this in terms of EU impact. The article aims to transcend this literature through assessing how domestic interpretations influence EU border transformation in conflict situations, taking Cyprus as a case study. Moreover, the objective is to fuse the literature on EU bordering impact and perceptions of the EU’s normative projection in conflict resolution. Pursuing this line of inquiry is an attempt to depart from the notion of borders being constructed solely by unidirectional EU logics of engagement or bordering practices to a conceptualization of the border as co-constituted space, where the interpretations of the EU’s normative projections by conflict parties, and the strategies that they pursue, can determine the relative openness of the EU border

    Thermodynamic and technical criteria for the optimal selection of the working fluid in a mini-ORC

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    Waste energy recovery (WER) is a suitable solution to improve the fuel utilization of Internal Combustion Engines (ICEs) by producing an eco-friendly electrical power from an energy source currently wasted. Organic Rankine Cycle (ORC) technology has been developed in the past few years to generate electric power from medium temperature (500 K – 800 K) ICE wasted thermal sources. Working fluid selection represents the first step in the design of an ORC. At the state of the art, authors where not able to select a single optimal organic fluid. This is mainly because of the different thermodynamic conditions of the heat sources which offer wasted thermal energy. This paper proposes a procedure for the ORC system preliminary working fluid selection, which takes into consideration thermodynamics and design parameters of the system components. The study is applied to WER systems specifically designed as bottoming cycles to ICE for transport applications. However, the method is quite general and makes the model easily adaptable to different heat sources. A steady state thermodynamic model of the system is developed via the software MATLAB. A wide variety of organic fluids (OF), such as R245fa, Solkatherm (SES36) and hexane have been investigated to identify the candidate which offers the best recovery opportunity. Regeneration is also included in this work. Results show that recover thermal energy in the regenerator is an essential method to improve power recovery when applying ORC to WER systems. The effect of superheating on the system power output has been investigated as well. It is capable to increase the cycle power output only when coupled with regeneration. The paper shows that the addition of a bottoming ORC to the ICE is convenient both in terms of recovered electric power (up to 14% of the engine nameplate power) and heat source utilization rate (up to 11 % heat source conversion into electricity). In addition, it is shown that water offers lower performance with respect to organic fluids when considering single stage radial expanders

    Structure of a model TiO2 photocatalytic interface

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    The interaction of water with TiO2 is crucial to many of its practical applications, including photocatalytic water splitting. Following the first demonstration of this phenomenon 40 years ago there have been numerous studies of the rutile single-crystal TiO2(110) interface with water. This has provided an atomic-level understanding of the water-TiO2 interaction. However, nearly all of the previous studies of water/TiO2 interfaces involve water in the vapour phase. Here, we explore the interfacial structure between liquid water and a rutile TiO2(110) surface pre-characterized at the atomic level. Scanning tunnelling microscopy and surface X-ray diffraction are used to determine the structure, which is comprised of an ordered array of hydroxyl molecules with molecular water in the second layer. Static and dynamic density functional theory calculations suggest that a possible mechanism for formation of the hydroxyl overlayer involves the mixed adsorption of O2 and H2O on a partially defected surface. The quantitative structural properties derived here provide a basis with which to explore the atomistic properties and hence mechanisms involved in TiO2 photocatalysis

    Effects of combined administration of FK 506 and the purine biosynthesis inhibitors mizoribine or mycophenolic acid on lymphocyte DNA synthesis and T cell activation molecule expression in human mixed lymphocyte cultures

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    Our objective was to obtain new information on the in vitro antilymphocytic action of the cytokine synthesis inhibitor FK 506 and the purine biosynthesis inhibitors mycophenolic acid (MPA; the active moiety of RS61443) and mizoribine (MZB) when used alone or in combination. When added at the initiation of six-day human mixed lymphocyte cultures (MLC), FK 506, MPA or MZB exhibited dose-dependent inhibition of T-lymphocyte DNA synthesis. FK 506, however, was 100-fold more potent than MPA, and 10000-fold more potent than MZB. Combination of FK 506 with either MPA or MZB, each at suboptional concentrations, produced no more than additive inhibitory effects on 3H thymidine incorporation. Two-colour flow cytometric analysis of lymphocytes revealed that none of the drugs affected cell surface activation molecule expression (CD25 = IL-2R 55 kD α-chain, HLA-DR or CD71 = transferrin receptor [TR]) on allostimulated CD4+ or CD8+ cells harvested at three days of culture. By day six, however, all three agents, at levels which markedly inhibited proliferation, suppressed the expression of activation markers on both CD4+ and CD8+ cells. Also at day six, inhibition of activation molecule expression on CD4+ cells was achieved with the combination of FK 506 and either MPA or MZB at concentrations which, on their own, were ineffective. These data provide new, additional information on the in vitro antilymphocytic action of FK 506, MPA and MZB when used alone and in combination. © 1993

    Blood pressure control in Italy: analysis of clinical data from 2005-2011 surveys on hypertension

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    Introduction: Blood pressure (BP) control is poorly achieved in hypertensive patients, worldwide. Aim: We evaluated clinic BP levels and the rate of BP control in hypertensive patients included in observational studies and clinical surveys published between 2005 and 2011 in Italy. Methods: We reviewed the medical literature to identify observational studies and clinical surveys on hypertension between January 2005 and June 2011, which clearly reported information on clinic BP levels, rates of BP control, proportions of treated and untreated patients, who were followed in different clinical settings (mostly in general practice, and also in outpatient clinics and hypertension centres). Results: The overall sample included 158 876 hypertensive patients (94 907 women, mean age 56.6 +/- 9.6 years, BMI 27.2 +/- 4.2 kg/m(2), known duration of hypertension 90.2 +/- 12.4 months). In the selected studies, average SBP and DBP levels were 145.7 +/- 15.9 and 87.5 +/- 9.7 mmHg, respectively; BP levels were higher in patients followed in hypertension centres (n = 10 724, 6.7%; 146.5 +/- 17.3/88.5 +/- 10.3 mmHg) than in those followed by general practitioners (n = 148 152, 93.3%; 143.5 +/- 13.9/84.8 +/- 8.9 mmHg; P < 0.01). More than half of the patients were treated (n = 91 318, 57.5%); among treated hypertensive patients, only 31 727 (37.0%) had controlled BP levels. Conclusion: The present analysis confirmed inadequate control of BP in Italy, independently of the clinical setting. Although some improvement was noted compared with a similar analysis performed between 1995 and 2005, these findings highlight the need for a more effective clinical management of hypertension

    Nonlinear guided waves and spatial solitons in a periodic layered medium

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    We overview the properties of nonlinear guided waves and (bright and dark) spatial optical solitons in a periodic medium created by a sequence of linear and nonlinear layers. First, we consider a single layer with a cubic nonlinear response (a nonlinear waveguide) embedded into a periodic layered linear medium, and describe nonlinear localized modes (guided waves and Bragg-like localized gap modes) and their stability. Then, we study modulational instability as well as the existence and stability of discrete spatial solitons in a periodic array of identical nonlinear layers, a one-dimensional nonlinear photonic crystal. Both similarities and differences with the models described by the discrete nonlinear Schrodinger equation (derived in the tight-binding approximation) and coupled-mode theory (valid for the shallow periodic modulations) are emphasized.Comment: 10 pages, 14 figure

    Calculation of atomic spontaneous emission rate in 1D finite photonic crystal with defects

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    We derive the expression for spontaneous emission rate in finite one-dimensional photonic crystal with arbitrary defects using the effective resonator model to describe electromagnetic field distributions in the structure. We obtain explicit formulas for contributions of different types of modes, i.e. radiation, substrate and guided modes. Formal calculations are illustrated with a few numerical examples, which demonstrate that the application of effective resonator model simplifies interpretation of results.Comment: Cent. Eur. J. Phys, in pres

    Influence of FK 506 (tacrolimus) on circulating CD4 <sup>+</sup> t cells expressing cd25 and cd45ra antigens in 19 patients with chronic progressive multiple sclerosis participating in an open label drug safety trial

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    We have taken the opportunity of a clinical trial of the potential efficacy and safety of FK 506 (tacrolimus) in chronic progressive multiple sclerosis (MS) to examine the influence of this potent new immunosuppressant on circulating T-lymphocytes in an otherwise healthy non-transplant population. Peripheral blood levels of subsets of CD4+ T lymphocytes expressing the activation molecule interleukin-2 receptor (p55 α chain; CD25) or the CD45RA isoform were determined sequentially in 19 patients that were treated continuously with oral FK 506 (starting dose 0.15 mg/kg/day) for 12 months. No significant change in the proportion of circulating CD25 + CD4+ cells was observed over the study period in which the mean trough plasma FK 506 level rose from 0.3 ±0.2 to 0.5 ±0.4 ng/ml. There was also no significant effect of FK 506 on the percentage of CD45RA + CD4 + cells in the peripheral blood at 12 months compared with pretreatment values. Analysis of a subgroup of 7 patients, who showed a sustained reduction in CD25 + CD4+ cells and a reciprocal increase in CD45RA* CD4 * cells for at least 6 months after start of treatment, did not reveal any difference in disability at one year compared with the treatment group as a whole. The side effects of FK 506 were mild and the overall degree of disability estimated by the mean Kurtzke expanded disability status scale (EDSS) score or the ambulation index did not deteriorate significantly in the 19 patients studied over the 12 months of FK 506 administration. © 1994 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted
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