87 research outputs found

    Stability Analysis of the LHC Cables for Transient Heat Depositions

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    The commissioning and the exploitation of the LHC require a good knowledge of the stability margins of the superconducting magnets with respect to beam induced heat depositions. Previous studies showed that simple numerical models are suitable to carry out stability calculations of multi-strands cables, and highlighted the relevance of the heat transfer model with the surrounding helium. In this paper we present a systematic scan of the stability margin of all types of LHC cables working at 1.9 Kagainst transient heat depositions. We specifically discuss the dependence of the stability margin on the parameters of the model, which provide an estimate of the uncertainty of the values quoted. The stability margin calculations have been performed using a zero-dimensional (0-D) numerical model, and a cooling model taking into account the relevant helium phases which may appear during a stability experiment: it includes Kapitza thermal resistance in superfluid He, boundary layer formation and heat transfer in He I, and considers the transition from nucleating boiling to film boiling during He gas formation

    3D right ventricular strain: comparative analysis of Tetralogy of Fallot and atrial septal defect

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    International audienceBackground: Right ventricular (RV) function assessment is crucial in CHD patients, especially in atrial septaldefect (ASD) and Tetralogy of Fallot (TOF) patients. Indeed, prognosis is very different between TOF patientswith pulmonary regurgitation and ASD patients, and only little is known about 3D deformation in RV overload. Purpose: The aim of our study was to assess RV remodeling differences between ASD, TOF patients andcontrols. Methods: We performed a prospective case­control study. We included 10 patients with an ASD (mean age53.3±21y) and 10 with TOF (mean age 34.9±18y) who were older than 16 years old, and compared them toa control group free from any cardiovascular disease (N=44, mean age 42.5±15y). 3D transthoracic RVechocardiographic sequences were acquired. Myocardial tracking was performed by a semi­automaticcommercial software. Output RV meshes included spatial correspondences. They were post­processed to alignthe data temporally and extract local deformation. Global and local statistics provided deformation patterns foreach subgroup of subjects. Results: Overall, ASD and TOF patients had similar but reduced RV ejection fraction (respectively 44.3±10and 44.5±12 %) and dilated right ventricles (mean RV EDV 158.3±100 and 115.4±46mL) using 3D analysis.Similar RV global area strain (GAS), global longitudinal strain (GLS) and global circumferential strain (GCS)were observed between the two groups. Compared to controls, ASD patients had lower GAS (­22.2±8 vs­29.4±5%; p=0.01), lower GCS (­12.9±4 vs ­17.1±4%; p=0.009) but similar GLS (p=0.07). TOF patientshad also lower GAS (­25.1±6%; p=0.03) but lower GLS (­10.0±3%; p=0.01) and similar GCS (­15.5±4%;p=0.4) in comparison with the control group. However, ASD patients had significantly lower CS in theinfundibular, inlet and membranous septum as compared with TOF patients (respectively p=0.02, p=0.05 andp=0.03). Conclusion: Volume overload in ASD patients seems to impact circumferential strain and preserve longitudinalstrain, whereas TOF patients tend to have lower longitudinal strain with preserved circumferential strain,probably because of the combination of RV pressure and volume overload. A larger cohort of patients couldhelp understand the insights of RV remodeling in congenital heart disease using 3D speckle­tracking imagin

    European Strategy for Particle Physics -- Accelerator R&D Roadmap

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    The 2020 update of the European Strategy for Particle Physics emphasised the importance of an intensified and well-coordinated programme of accelerator R&D, supporting the design and delivery of future particle accelerators in a timely, affordable and sustainable way. This report sets out a roadmap for European accelerator R&D for the next five to ten years, covering five topical areas identified in the Strategy update. The R&D objectives include: improvement of the performance and cost-performance of magnet and radio-frequency acceleration systems; investigations of the potential of laser / plasma acceleration and energy-recovery linac techniques; and development of new concepts for muon beams and muon colliders. The goal of the roadmap is to document the collective view of the field on the next steps for the R&D programme, and to provide the evidence base to support subsequent decisions on prioritisation, resourcing and implementation.Comment: 270 pages, 58 figures. Editor: N. Mounet. LDG chair: D. Newbold. Panel chairs: P. V\'edrine (HFM), S. Bousson (RF), R. Assmann (plasma), D. Schulte (muon), M. Klein (ERL). Panel editors: B. Baudouy (HFM), L. Bottura (HFM), S. Bousson (RF), G. Burt (RF), R. Assmann (plasma), E. Gschwendtner (plasma), R. Ischebeck (plasma), C. Rogers (muon), D. Schulte (muon), M. Klein (ERL

    Reduced costs with bisoprolol treatment for heart failure - An economic analysis of the second Cardiac Insufficiency Bisoprolol Study (CIBIS-II)

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    Background Beta-blockers, used as an adjunctive to diuretics, digoxin and angiotensin converting enzyme inhibitors, improve survival in chronic heart failure. We report a prospectively planned economic analysis of the cost of adjunctive beta-blocker therapy in the second Cardiac Insufficiency BIsoprolol Study (CIBIS II). Methods Resource utilization data (drug therapy, number of hospital admissions, length of hospital stay, ward type) were collected prospectively in all patients in CIBIS . These data were used to determine the additional direct costs incurred, and savings made, with bisoprolol therapy. As well as the cost of the drug, additional costs related to bisoprolol therapy were added to cover the supervision of treatment initiation and titration (four outpatient clinic/office visits). Per them (hospital bed day) costings were carried out for France, Germany and the U.K. Diagnosis related group costings were performed for France and the U.K. Our analyses took the perspective of a third party payer in France and Germany and the National Health Service in the U.K. Results Overall, fewer patients were hospitalized in the bisoprolol group, there were fewer hospital admissions perpatient hospitalized, fewer hospital admissions overall, fewer days spent in hospital and fewer days spent in the most expensive type of ward. As a consequence the cost of care in the bisoprolol group was 5-10% less in all three countries, in the per them analysis, even taking into account the cost of bisoprolol and the extra initiation/up-titration visits. The cost per patient treated in the placebo and bisoprolol groups was FF35 009 vs FF31 762 in France, DM11 563 vs DM10 784 in Germany and pound 4987 vs pound 4722 in the U.K. The diagnosis related group analysis gave similar results. Interpretation Not only did bisoprolol increase survival and reduce hospital admissions in CIBIS II, it also cut the cost of care in so doing. This `win-win' situation of positive health benefits associated with cost savings is Favourable from the point of view of both the patient and health care systems. These findings add further support for the use of beta-blockers in chronic heart failure

    HE-LHC: The High-Energy Large Hadron Collider – Future Circular Collider Conceptual Design Report Volume 4

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    In response to the 2013 Update of the European Strategy for Particle Physics (EPPSU), the Future Circular Collider (FCC) study was launched as a world-wide international collaboration hosted by CERN. The FCC study covered an energy-frontier hadron collider (FCC-hh), a highest-luminosity high-energy lepton collider (FCC-ee), the corresponding 100 km tunnel infrastructure, as well as the physics opportunities of these two colliders, and a high-energy LHC, based on FCC-hh technology. This document constitutes the third volume of the FCC Conceptual Design Report, devoted to the hadron collider FCC-hh. It summarizes the FCC-hh physics discovery opportunities, presents the FCC-hh accelerator design, performance reach, and staged operation plan, discusses the underlying technologies, the civil engineering and technical infrastructure, and also sketches a possible implementation. Combining ingredients from the Large Hadron Collider (LHC), the high-luminosity LHC upgrade and adding novel technologies and approaches, the FCC-hh design aims at significantly extending the energy frontier to 100 TeV. Its unprecedented centre-of-mass collision energy will make the FCC-hh a unique instrument to explore physics beyond the Standard Model, offering great direct sensitivity to new physics and discoveries

    FCC-ee: The Lepton Collider – Future Circular Collider Conceptual Design Report Volume 2

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