1,722 research outputs found

    Muon Catalyzed Fusion in 3 K Solid Deuterium

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    Muon catalyzed fusion in deuterium has traditionally been studied in gaseous and liquid targets. The TRIUMF solid-hydrogen-layer target system has been used to study the fusion reaction rates in the solid phase of D_2 at a target temperature of 3 K. Products of two distinct branches of the reaction were observed; neutrons by a liquid organic scintillator, and protons by a silicon detector located inside the target system. The effective molecular formation rate from the upper hyperfine state of μd\mu d and the hyperfine transition rate have been measured: λ~(3/2)=2.71(7)stat.(32)syst.μ/s\tilde{\lambda}_(3/2)=2.71(7)_{stat.}(32)_{syst.} \mu/s, and λ~(3/2)(1/2)=34.2(8)stat.(1)syst.μ/s\tilde{\lambda}_{(3/2)(1/2)} =34.2(8)_{stat.}(1)_{syst.} \mu /s. The molecular formation rate is consistent with other recent measurements, but not with the theory for isolated molecules. The discrepancy may be due to incomplete thermalization, an effect which was investigated by Monte Carlo calculations. Information on branching ratio parameters for the s and p wave d+d nuclear interaction has been extracted.Comment: 19 pages, 11 figures, submitted to PRA Feb 20, 199

    SEOM Clinical Guideline for the diagnosis and treatment of esophageal cancer (2016)

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    Esophageal cancer (EC) is an aggressive tumor that represents the 6th most common cause of cancer death worldwide. The estimated incidence in Spain is 2090 cases/year. Two main pathological subtypes exist, squamous cell carcinoma and adenocarcinoma. The main differences between them are localization and underlying factors which are the principal cause of the recent incidence changes observed in west countries. Staging techniques and treatment options which combine surgery, chemotherapy and radiotherapy, reflected the high complexity of the EC management. An undeniably multidisciplinary approach is, therefore, required. In this guide, we review the status of current diagnosis and treatment, define evidence and propose recommendations

    Beveridge on idleness

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    Beveridge's wartime proposals to eliminate idleness relied on the precepts of Keynesian economics and substantial extensions in the powers of central government to regulate industry and labour. Using convention theory, this paper demonstrates how these stipulations proved politically untenable. With the disappearance of full employment in the 1980s, the labour market problems Beveridge encountered in his youth have re-emerged accompanied by old problems of working poverty. Established forms of labour market analysis are obsolescent and employment rights disappear. The paper suggests a more decentralized and variable analysis of relations between work and idleness may offer a way forward

    Resonant Formation of dμtd\mu t Molecules in Deuterium: An Atomic Beam Measurement of Muon Catalyzed dt Fusion

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    Resonant formation of dμtd\mu t molecules in collisions of muonic tritium (μt\mu t) on D2_2 was investigated using a beam of μt\mu t atoms, demonstrating a new direct approach in muon catalyzed fusion studies. Strong epithermal resonances in dμtd\mu t formation were directly revealed for the first time. From the time-of-flight analysis of 2036±1162036\pm 116 dtdt fusion events, a formation rate consistent with 0.73±(0.16)meas±(0.09)model0.73\pm (0.16)_{meas} \pm (0.09)_{model} times the theoretical prediction was obtained. For the largest peak at a resonance energy of 0.423±0.0370.423 \pm 0.037 eV, this corresponds to a rate of (7.1±1.8)×109(7.1 \pm 1.8) \times 10^9 s1^{-1}, more than an order of magnitude larger than those at low energies.Comment: To appear in Phys. Rev. Let

    Theory of excited state absorptions in phenylene-based π\pi-conjugated polymers

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    Within a rigid-band correlated electron model for oligomers of poly-(paraphenylene) (PPP) and poly-(paraphenylenevinylene) (PPV), we show that there exist two fundamentally different classes of two-photon Ag_g states in these systems to which photoinduced absorption (PA) can occur. At relatively lower energies there occur Ag_g states which are superpositions of one electron - one hole (1e--1h) and two electron -- two hole (2e--2h) excitations, that are both comprised of the highest delocalized valence band and the lowest delocalized conduction band states only. The dominant PA is to one specific member of this class of states (the mAg_g). In addition to the above class of Ag_g states, PA can also occur to a higher energy kAg_g state whose 2e--2h component is {\em different} and has significant contributions from excitations involving both delocalized and localized bands. Our calculated scaled energies of the mAg_g and the kAg_g agree reasonably well to the experimentally observed low and high energy PAs in PPV. The calculated relative intensities of the two PAs are also in qualitative agreement with experiment. In the case of ladder-type PPP and its oligomers, we predict from our theoretical work a new intense PA at an energy considerably lower than the region where PA have been observed currently. Based on earlier work that showed that efficient charge--carrier generation occurs upon excitation to odd--parity states that involve both delocalized and localized bands, we speculate that it is the characteristic electronic nature of the kAg_g that leads to charge generation subsequent to excitation to this state, as found experimentally.Comment: Revtex4 style, 2 figures inserted in the text, three tables, 10 page

    Sensitivity Studies for Third-Generation Gravitational Wave Observatories

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    Advanced gravitational wave detectors, currently under construction, are expected to directly observe gravitational wave signals of astrophysical origin. The Einstein Telescope, a third-generation gravitational wave detector, has been proposed in order to fully open up the emerging field of gravitational wave astronomy. In this article we describe sensitivity models for the Einstein Telescope and investigate potential limits imposed by fundamental noise sources. A special focus is set on evaluating the frequency band below 10Hz where a complex mixture of seismic, gravity gradient, suspension thermal and radiation pressure noise dominates. We develop the most accurate sensitivity model, referred to as ET-D, for a third-generation detector so far, including the most relevant fundamental noise contributions.Comment: 13 pages, 7 picture

    Scientific Potential of Einstein Telescope

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    Einstein gravitational-wave Telescope (ET) is a design study funded by the European Commission to explore the technological challenges of and scientific benefits from building a third generation gravitational wave detector. The three-year study, which concluded earlier this year, has formulated the conceptual design of an observatory that can support the implementation of new technology for the next two to three decades. The goal of this talk is to introduce the audience to the overall aims and objectives of the project and to enumerate ET's potential to influence our understanding of fundamental physics, astrophysics and cosmology.Comment: Conforms to conference proceedings, several author names correcte
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