220 research outputs found

    Injection Scheme with Deflecting Cavity for Ultimate Storage Ring

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    We suggest a new on-axis injection scheme that uses two deflecting cavities to remove the tilt of the stored beam, and to kick the injected beam into the ring. In this new injection scheme, an injected beam with a certain angle is overlaid on the stored beam position in transverse phase space through the second deflecting cavity. (Note that the injected beam has separated phase with the stored beam in longitudinal phase space). We present theoretical analysis and numerical simulations of the stored beam and injected beam with the new injection scheme

    Chromophore Ordering by Confinement into Carbon Nanotubes

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    International audienceWe report an experimental study on the confinement of oligothiophene derivatives into single-walled carbon nanotubes over a large range of diameter (from 0.68 to 1.93 nm). We evidence by means of Raman spectroscopy and transmission electron microscopy that the supramolecular organizations of the confined oligothiophenes depend on the nanocontainer size. The Raman Radial Breathing Mode frequency is shown to be monitored by both the number of confined molecules into a nanotube section and the competition between oligothiophene/oligothiophene and oligothiophene/tube wall interactions. We finally propose simple Raman criteria to characterize oligothiophene supramolecular organization at the nanoscale

    Structure near K−K^-+pp+pp threshold in the in-flight 3^3He(K−,Λp)n(K^-,\Lambda p)n reaction

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    To search for an S= -1 di-baryonic state which decays to Λp\Lambda p, the 3He(K−,Λp)nmissing {\rm{}^3He}(K^-,\Lambda p)n_{missing} reaction was studied at 1.0 GeV/cc. Unobserved neutrons were kinematically identified from the missing mass MXM_X of the 3He(K−,Λp)X {\rm{}^3He}(K^-,\Lambda p)X reaction in order to have a large acceptance for the Λpn\Lambda pn final state. The observed Λpn\Lambda p n events, distributed widely over the kinematically allowed region of the Dalitz plot, establish that the major component comes from a three nucleon absorption process. A concentration of events at a specific neutron kinetic energy was observed in a region of low momentum transfer to the Λp\Lambda p. To account for the observed peak structure, the simplest S-wave pole was assumed to exist in the reaction channel, having Breit-Wigner form in energy and with a Gaussian form-factor. A minimum χ2\chi^2 method was applied to deduce its mass MX =M_X\ = 2355 −8+6 ^{+ 6}_{ - 8} (stat.) ±12 \pm 12 (syst.) MeV/c2^2, and decay-width ΓX =\Gamma_X\ = 110 −17+19 ^{+ 19}_{ - 17} (stat.) ±27 \pm 27 (syst.) MeV/c2^2, respectively. The form factor parameter QX∌Q_X \sim 400 MeV/cc implies that the range of interaction is about 0.5Comment: 12pages, 8 figure

    Using irregularly spaced current peaks to generatean isolated attosecond X-ray pulse in free-electron lasers

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    A method is proposed to generate an isolated attosecond X-ray pulse in free-electron lasers, using irregularly spaced current peaks induced in an electron beam through interaction with an intense short-pulse optical laser. In comparison with a similar scheme proposed in a previous paper, the irregular arrangement of current peaks significantly improves the contrast between the main and satellite pulses, enhances the attainable peak power and simplifies the accelerator layout. Three different methods are proposed for this purpose and achievable performances are computed under realistic conditions. Numerical simulations carried out with the best configuration show that an isolated 7.7keV X-ray pulse with a peak power of 1.7TW and pulse length of 70as can be generated. In this particular example, the contrast is improved by two orders of magnitude and the peak power is enhanced by a factor of three, when compared with the previous scheme.1152Ysciescopu

    Anastomotic leak management after a low anterior resection leading to recurrent abdominal compartment syndrome: a case report and review of the literature

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    <p>Abstract</p> <p>Introduction</p> <p>Low anterior resection is usually the procedure of choice for rectal cancer, but a series of complications often accompany this procedure. This case report describes successful management of an intricate anastomotic leak after a low anterior resection.</p> <p>Case presentation</p> <p>A 66-year-old Caucasian man was admitted to our hospital and diagnosed with a low rectal adenocarcinoma. He underwent a low anterior resection but subsequently developed fecal peritonitis due to an anastomotic leak. He was operated on again but developed abdominal compartment syndrome, multi-organ failure and sepsis. He was aggressively treated in the intensive care unit and in the operating room. Overall, the patient underwent four laparotomies and stayed in the intensive care unit for 75 days. He was discharged after 3 months of hospitalization.</p> <p>Conclusion</p> <p>Abdominal compartment syndrome may present as a devastating complication of damage control laparotomy. Prompt recognition and goal-directed management are the cornerstones of treatment.</p

    A Long Baseline Neutrino Oscillation Experiment Using J-PARC Neutrino Beam and Hyper-Kamiokande

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    Document submitted to 18th J-PARC PAC meeting in May 2014. 50 pages, 41 figuresDocument submitted to 18th J-PARC PAC meeting in May 2014. 50 pages, 41 figuresDocument submitted to 18th J-PARC PAC meeting in May 2014. 50 pages, 41 figuresHyper-Kamiokande will be a next generation underground water Cherenkov detector with a total (fiducial) mass of 0.99 (0.56) million metric tons, approximately 20 (25) times larger than that of Super-Kamiokande. One of the main goals of Hyper-Kamiokande is the study of CPCP asymmetry in the lepton sector using accelerator neutrino and anti-neutrino beams. In this document, the physics potential of a long baseline neutrino experiment using the Hyper-Kamiokande detector and a neutrino beam from the J-PARC proton synchrotron is presented. The analysis has been updated from the previous Letter of Intent [K. Abe et al., arXiv:1109.3262 [hep-ex]], based on the experience gained from the ongoing T2K experiment. With a total exposure of 7.5 MW ×\times 107^7 sec integrated proton beam power (corresponding to 1.56×10221.56\times10^{22} protons on target with a 30 GeV proton beam) to a 2.52.5-degree off-axis neutrino beam produced by the J-PARC proton synchrotron, it is expected that the CPCP phase ÎŽCP\delta_{CP} can be determined to better than 19 degrees for all possible values of ÎŽCP\delta_{CP}, and CPCP violation can be established with a statistical significance of more than 3 σ3\,\sigma (5 σ5\,\sigma) for 7676% (5858%) of the ÎŽCP\delta_{CP} parameter space

    Fermi level shift in carbon nanotubes by dye confinement

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    International audienceDye confinement into carbon nanotube significantly affects the electronic charge density distribution of the final hybrid system. Using the electron-phonon coupling sensitivity of the Raman G-band, we quantify experimentally how charge transfer from thiophene oligomers to single walled carbon nanotube is modulated by the diameter of the nano-container and its metallic or semiconducting character. This charge transfer is shown to restore the electron-phonon coupling into defected metallic nanotubes. For sub-nanometer diameter tube, an electron transfer optically activated is observed when the excitation energy matches the HOMO-LUMO transition of the confined oligothiophene. This electron doping accounts for an important enhancement of the photoluminescence intensity up to a factor of nearly six for optimal confinement configuration. This electron transfer shifts the Fermi level, acting on the photoluminescence efficiency. Therefore, thiophene oligomer encapsulation allows modulating the electronic structure and then the optical properties of the hybrid system
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