76 research outputs found

    Thermal Performance of the LHC External Auxiliary Bus-Bar Tube: Mathematical Modelling

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    The Large Hadron Collider (LHC) externally routed auxiliary bus-bar tube (EAB) will house the electrical feeders of the LHC short straight section (SSS) correcting magnets. The superconducting wires w ill be contained in a stainless steel tube and immersed in a quasi-static helium bath. The EAB thermal performance during the cooling of the magnets down to the operating temperature of 1.9 K is studi ed. A 3-d finite element thermal model of the EAB during a cooling process from 293 K to 4.5 K is described. The semi-analytical model of the EAB cool-down from 4.5 K to 1.9 K is also presented

    The Electrical Distribution Feed Box for the LHC Prototype Cell

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    The Electrical Distribution Feed Box (DFB) for the Large Hadron Collider (LHC) Prototype Cell (String 2) is a 6 meter-long 4.6 K / 0.135 MPa liquid helium cryostat which supports and cools 13 kA and 600 A High-Temperature Superconductor (HTS) current leads. These are used for powering the String 2 main dipole and quadrupole superconducting magnets, together with their correctors. The DFB also incorporates the l-plate between its saturated liquid helium bath and the magnet pressurized superfluid helium bath at 1.9 K/ 0.13 MPa. The DFB is built within the frame of a collaboration between CERN and the Budker Institute of Nuclear Physics (Novosibirsk, Russian Federation). It is a complex cryostat satisfying a number of constraints (space available, accessibility, integration) and combining different technologies such as mechanical and electrical engineering, superconductivity, cryogenics and vacuum. The current status of the design and construction of the DFB for the LHC Prototype Cell, together with an outlook towards the LHC arc DFB's, is given

    Thermal Design and Performance of the Electrical Distribution Feed Box of the LHC prototype cell

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    The Electrical Distribution Feed Box (DFBS) is a 4.5 K saturated liquid helium cryostat constructed for the Large Hadron Collider (LHC) Prototype Cell (String 2). The thermal design of the DFBS is presented, with emphasis on the modelling of the cooling of the current lead chimneys via the helium bath boil-off gas and on the design of the lambda plate. The expected performance is compared to measurements done during the first operation phase of the LHC prototype cell

    Le compartiment sauvage de la carotte en France : des ressources génétiques importantes et pourtant méconnues

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    La France est considérée comme centre secondaire de diversification de la carotte, du fait de l’activité importante de sélection (par des maraîchers ou semenciers), ce qui justifie les actions de conservation et connaissance des variétés anciennes menées par le réseau de ressources génétiques « Carotte et autres Daucus ». Par contre, le compartiment sauvage est méconnu et sous-exploité, alors qu’il s’agit d’une espèce pour laquelle de nombreuses populations existent sur le territoire français, avec une situation très contrastée. Si la carotte sauvage D. carota spp carota n’est pas en danger, d’autres sous espèces sont protégées (ssp gadecaei) ou menacées du fait de la dégradation de leur milieux naturels notamment en zone littorale ou de possibles introgressions avec la sous-espèce carota. Le travail présenté porte donc sur : i/ la sauvegarde et la mise à disposition des ressources génétiques sauvages, à travers l’inventaire de populations in situ et la constitution de collections ex-situ ; ii/ l’approfondissement de la connaissance et de l’identification taxonomique des sous-espèces sauvages ; iii/ la connaissance de la diversité au sein du compartiment sauvage (marqueurs SSR et données écologiques) ; et iv/ l’évaluation des ressources génétiques sauvages de carotte pour permettre leur exploitation (fertilité, croisements avec le compartiment cultivé, tolérance à différents bioagresseurs). Ce programme fait l’objet du soutien d’un contrat de branche du ministère de l’agriculture et implique les membres du réseau « Carotte et autres Daucus ».

    Medical treatment of renal cancer: new horizons.

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    Renal cell carcinoma (RCC) makes up 2-3% of adult cancers. The introduction of tyrosine kinase inhibitors (TKIs) and mammalian target of rapamycin inhibitors in the mid-2000s radically changed the management of RCC. These targeted treatments superseded immunotherapy with interleukin-2 and interferon. The pendulum now appears to be shifting back towards immunotherapy, with the evidence of prolonged overall survival of patients with metastatic RCC on treatment with the anti-programmed cell death 1 ligand monoclonal antibody, nivolumab. Clinical prognostic criteria aid prediction of relapse risk for resected localised disease. Unfortunately, for patients at high risk of relapse, no adjuvant treatment has yet shown benefit, although further trials are yet to report. Clinical prognostic models also have a role in the management of advanced disease; now there is a pressing need for predictive biomarkers to direct therapy. Treatment selection for metastatic disease is currently based on histology, prognostic group and patient preference based on side effect profile. In this article, we review the current medical and surgical management of localised, oligometastatic and advanced RCC, including side effect management and the evidence base for management of poor-risk and non-clear cell disease. We discuss recent results from clinical trials and how these are likely to shape future practice and a renaissance of immunotherapy for renal cell cancer

    Characterization of Geographical and Meteorological Parameters

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    [EN]This chapter is devoted to the introduction of some geographical and meteorological information involved in the numerical modeling of wind fields and solar radiation. First, a brief description of the topographical data given by a Digital Elevation Model and Land Cover databases is provided. In particular, the Information System of Land Cover of Spain (SIOSE) is considered. The study is focused on the roughness length and the displacement height parameters that appear in the logarithmic wind profile, as well as in the albedo related to solar radiation computation. An extended literature review and characterization of both parameters are reported. Next, the concept of atmospheric stability is introduced from the Monin–Obukhov similarity theory to the recent revision of Zilitinkevich of the Neutral and Stable Boundary Layers (SBL). The latter considers the effect of the free-flow static stability and baroclinicity on the turbulent transport of momentum and of the Convective Boundary Layers (CBL), more precisely, the scalars in the boundary layer, as well as the model of turbulent entrainment

    Matching an oscillator model to a phase response curve

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    The Phase Response Curve (PRC) has proven a useful tool for the reduction of complex oscillator models. It is also an information often experimentally available to the biologist. This paper introduces a numerical tool based on the sensitivity analysis of the PRC to adapt initial model parameters in order to match a particular PRC shape. We illustrate the approach on a simple biochemical model of circadian oscillator. © 2011 IEEE

    Sensitivity analysis of circadian entrainment in the space of phase response curves

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    Sensitivity analysis is a classical and fundamental tool to evaluate the role of a given parameter in a given system characteristic. Because the phase response curve is a fundamental input-output characteristic of oscillators, we developed a sensitivity analysis for oscillator models in the space of phase response curves. The proposed tool can be applied to high-dimensional oscillator models without facing the curse of dimensionality obstacle associated with numerical exploration of the parameter space. Application of this tool to a state-of-the-art model of circadian rhythms suggests that it can be useful and instrumental to biological investigations
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