618 research outputs found

    A Multi Megawatt Cyclotron Complex to Search for CP Violation in the Neutrino Sector

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    A Multi Megawatt Cyclotron complex able to accelerate H2+ to 800 MeV/amu is under study. It consists of an injector cyclotron able to accelerate the injected beam up to 50 MeV/n and of a booster ring made of 8 magnetic sectors and 8 RF cavities. The magnetic field and the forces on the superconducting coils are evaluated using the 3-D code OPERA. The injection and extraction trajectories are evaluated using the well tested codes developed by the MSU group in the '80s. The advantages to accelerate H2+ are described and preliminary evaluations on the feasibility and expected problems to build the injector cyclotron and the ring booster are here presented.Comment: Presentation at Cyclotron'10 conference, Lanzhou, China, Sept 7, 201

    Design of the RF system for a 250 A.MeV superconducting cyclotron

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    International audienceA superconducting cyclotron accelerating q/A=0.5 ions up to 250 A.MeV, for medical applications and radioisotopes production (SCENT project) is being studied at Laboratori Nazionali del Sud in Catania. The RF system, working in the fourth harmonic, is based on four cavities operating at 93 MHz, which are connected in the central region. The paper describes an unusual multistem RF design, performed with 3D electromagnetic codes. The aim is to obtain a cavity, completely housed in the valley, with a voltage distribution going from 65 kV in the injection region to a peak value of 120 kV in the extraction region, and a low power consumption

    Representations of Time Coordinates in FITS

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    In a series of three previous papers, formulation and specifics of the representation of World Coordinate Transformations in FITS data have been presented. This fourth paper deals with encoding time. Time on all scales and precisions known in astronomical datasets is to be described in an unambiguous, complete, and self-consistent manner. Employing the well--established World Coordinate System (WCS) framework, and maintaining compatibility with the FITS conventions that are currently in use to specify time, the standard is extended to describe rigorously the time coordinate. World coordinate functions are defined for temporal axes sampled linearly and as specified by a lookup table. The resulting standard is consistent with the existing FITS WCS standards and specifies a metadata set that achieves the aims enunciated above.Comment: FITS WCS Paper IV: Time. 27 pages, 11 table

    Finite element analysis of horizontal axis wind turbines performance

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    This paper presents an aeroelastic formulation based on the Finite Element Method (FEM) to predict the performance of an isolated horizontal axis wind turbine. Hamilton’s principle is applied to derive the equations of blade(s) aeroelasticity, based on a nonlinear beam model coupled with Beddoes-Leishman unsteady sectional aerodynamics. A devoted fifteen-degrees of freedom finite element, able to accurately model the kinematics and elastic behavior of rotating blades, is introduced and the spatial discretization of the aeroelastic equations is carried-out yielding a set of coupled nonlinear ordinary differential equations that are then solved by a time-marching algorithm. The proposed formulation may be enhanced to face the analysis of advanced blade shapes, including the presence of the tower, and represents the first step of an ongoing activity on wind energy based on a FEM approach. Due to similarities between wind turbine and helicopter rotor blades aeroelasticity, validation results firstly concern with the aeroelastic response of a helicopter rotor in hovering. Next, the performance of a wind turbine in terms of blade elastic response and delivered power are predicted and compared with available literature data

    Finite element analysis of horizontal axis wind turbines performance

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    This paper presents an aeroelastic formulation based on the Finite Element Method (FEM) to predict the performance of an isolated horizontal axis wind turbine. Hamilton’s principle is applied to derive the equations of blade(s) aeroelasticity, based on a nonlinear beam model coupled with Beddoes-Leishman unsteady sectional aerodynamics. A devoted fifteen-degrees of freedom finite element, able to accurately model the kinematics and elastic behavior of rotating blades, is introduced and the spatial discretization of the aeroelastic equations is carried-out yielding a set of coupled nonlinear ordinary differential equations that are then solved by a time-marching algorithm. The proposed formulation may be enhanced to face the analysis of advanced blade shapes, including the presence of the tower, and represents the first step of an ongoing activity on wind energy based on a FEM approach. Due to similarities between wind turbine and helicopter rotor blades aeroelasticity, validation results firstly concern with the aeroelastic response of a helicopter rotor in hovering. Next, the performance of a wind turbine in terms of blade elastic response and delivered power are predicted and compared with available literature data

    Anomalous radio emission from dust in the Helix

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    A byproduct of experiments designed to map the CMB is the recent detection of a new component of foreground Galactic emission. The anomalous foreground at ~ 10--30 GHz, unexplained by traditional emission mechanisms, correlates with 100um dust emission. We report that in the Helix the emission at 31 GHz and 100um are well correlated, and exhibit similar features on sky images, which are absent in H\beta. Upper limits on the 250 GHz continuum emission in the Helix rule out cold grains as candidates for the 31 GHz emission, and provide spectroscopic evidence for an excess at 31 GHz over bremsstrahlung. We estimate that the 100um-correlated radio emission, presumably due to dust, accounts for at least 20% of the 31 GHz emission in the Helix. This result strengthens previous tentative interpretations of diffuse ISM spectra involving a new dust emission mechanism at radio frequencies. Very small grains have not been detected in the Helix, which hampers interpreting the new component in terms of spinning dust. The observed iron depletion in the Helix favors considering the identity of this new component to be magnetic dipole emission from hot ferromagnetic grains. The reduced level of free-free continuum we report also implies an electronic temperature of Te=4600\pm1200K for the free-free emitting material, which is significantly lower than the temperature of 9500\pm500K inferred from collisionally-excited lines (abridged).Comment: Accepted for publication in Ap

    The antibody-drug conjugate loncastuximab tesirine for the treatment of diffuse large B-cell lymphoma

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    Diffuse large B-cell lymphoma (DLBCL) is a heterogenous subtype of non-Hodgkin lymphoma. Relapsed/refractory disease represents remains an unmet medical need, despite the introduction of novel cellular and targeted therapies. Loncastuximab tesirine is a cluster of differentiation19-targeting antibody-drug conjugate approved by the US Food and Drug Administration for relapsed DLBCL after 2 lines of systemic therapy based on a trial showing a 48.3% overall response rate. The spectrum of its clinical applications is expanding and is now being tested in other B-cell malignancies
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