1,398 research outputs found
Evaluating the Factor Structure of the Emotion Dysregulation Scale-Short (EDS-s): A Preliminary Study
Emotion dysregulation (ED) can be considered a psychopathological transdiagnostic dimension, the presence of which should be reliably screened in clinical settings. The aim of the current study was to validate the Italian version of the Emotion Dysregulation Scale-short (EDS-s), a brief self-report tool assessing emotion dysregulation, in a non-clinical sample of 1087 adults (768 women and 319 men). We also assessed its convergent validity with scales measuring binge eating and general psychopathology. Structural equation modeling suggested the fit of a one-factor model refined with correlations between the errors of three pairs of items (Ï2 = 255.56, df = 51, p < 0.001, RMSEA = 0.08, CFI = 0.94, TLI = 0.93, SRMR = 0.04). The EDS-s demonstrated satisfactory internal consistency (ordinal alpha = 0.94). Moreover, EDS-s scores partly explained the variance of both binge eating (0.35, p < 0.001) and general psychopathology (0.60, p < 0.001). In conclusion, the EDS-s can be considered to be a reliable and valid measure of ED
Criticality and conformality in the random dimer model
In critical systems, the effect of a localized perturbation affects points that are arbitrarily far from the perturbation location. In this paper, we study the effect of localized perturbations on the solution of the random dimer problem in two dimensions. By means of an accurate numerical analysis, we show that a local perturbation of the optimal covering induces an excitation whose size is extensive with finite probability. We compute the fractal dimension of the excitations and scaling exponents. In particular, excitations in random dimer problems on nonbipartite lattices have the same statistical properties of domain walls in spin glass. Excitations produced in bipartite lattices, instead, are compatible with a loop-erased self-avoiding random walk process. In both cases, we find evidence of conformal invariance of the excitations that is compatible with SLEÎș with parameter Îș depending on the bipartiteness of the underlying lattice onl
Low-field Instabilities in NbSn Multifilamentary Wires: the Possible Role of Unreacted Nb
We report an experimental study aiming to demonstrate the not negligible role of unreacted Nb on the magnetic instabilities in superconducting NbSn multifilamentary wires, observable through partial flux jumps at magnetic field values below 0.5 T. The analysed wires were recently developed for use as dipoles required in future high-energy proton accelerators and are based on powder-in-tube technology. We studied both unreacted (only involving Nb filaments) and reacted wires, finding flux jump instabilities in both cases when performing magnetic measurements. The results can be interpreted on the basis of the critical state model and are coherent with the intrinsic stability criterion
Finite element stress analysis of the CMS magnet coil
The Compact Muon Solenoid (CMS) is one of the experiments which are being designed in the framework of the Large Hadron Collider (LHC) project at CERN. The design field of the CMS magnet is 4 T, the magnetic length is 12.38 m and the aperture is 6.36 m. This is achieved with a 4 layer-5 module superconducting Al-stabilized coil energised at a nominal current of 20 kA. The finite element analysis (FEA) carried out is axisymmetric elasto-plastic. FEA has also been carried out on the suspension system and on the conductor. (8 refs)
Study of coupling loss on bi-columnar BSCCO/Ag tapes by a.c. susceptibility measurements
Coupling losses were studied in composite tapes containing superconducting
material in the form of two separate stacks of densely packed filaments
embedded in a metallic matrix of Ag or Ag alloy. This kind of sample geometry
is quite favorable for studying the coupling currents and in particular the
role of superconducting bridges between filaments. By using a.c. susceptibility
technique, the electromagnetic losses as function of a.c. magnetic field
amplitude and frequency were measured at the temperature T = 77 K for two tapes
with different matrix composition. The length of samples was varied by
subsequent cutting in order to investigate its influence on the dynamics of
magnetic flux penetration. The geometrical factor which takes into
account the demagnetizing effects was established from a.c. susceptibility data
at low amplitudes. Losses vs frequency dependencies have been found to agree
nicely with the theoretical model developed for round multifilamentary wires.
Applying this model, the effective resistivity of the matrix was determined for
each tape, by using only measured quantities. For the tape with pure silver
matrix its value was found to be larger than what predicted by the theory for
given metal resistivity and filamentary architecture. On the contrary, in the
sample with a Ag/Mg alloy matrix, an effective resistivity much lower than
expected was determined. We explain these discrepancies by taking into account
the properties of the electrical contact of the interface between the
superconducting filaments and the normal matrix. In the case of soft matrix of
pure Ag, this is of poor quality, while the properties of alloy matrix seem to
provoke an extensive creation of intergrowths which can be actually observed in
this kind of samples.Comment: 20 pages 11 figure, submitted to Superconductor Science and
Technolog
Neurocognitive and Psychopathological Predictors of Weight Loss After Bariatric Surgery: A 4-Year Follow-Up Study
Twenty to thirty percent of patients experience weight regain at mid and long-term follow- up. Impaired cognitive functions are prevalent in people suffering from obesity and in those with binge eating disorder, thereby, affecting the weight-loss outcomes. The aim of our study was to investigate neurocognitive and psychopathological predictors of surgical efficacy in terms of percentage of excess weight loss (%EWL) at follow-up intervals of one year and 4-year. Psychosocial evaluation was completed in a sample of 78 bariatric surgery candidates and included psychometric instruments and a cognitive battery of neuropsychological tests. A schedule of 1-year and 4-year follow-ups was implemented. Wisconsin Sorting Card Test total correct responses, scores on the Ravenâs Progressive Matrices Test, and age predicted %EWL at, both, early and long-term periods after surgery while the severity of pre-operative binge eating (BED) symptoms were associated with lower %EWL only four years after the operation. Due to the role of pre-operative BED in weight loss maintenance, the affected patients are at risk of suboptimal response requiring ongoing clinical monitoring, and psychological and pharmacological interventions when needed. As a result of our findings and in keeping with the latest guidelines we encourage neuropsychological assessment of bariatric surgery candidates. This data substantiated the rationale of providing rehabilitative interventions tailored to cognitive domains and time specific to the goal of supporting patients in their post-surgical course
NbSn conductor development and characterization for NED
The main purpose of Next European Dipole (NED) project is to design and to build an NbSn ~ 15 T dipole magnet. Due to budget constraints, NED is mainly focused on superconducting cable development and production. In this work, an update is given on the NED conductor development by Alstom-MSA and SMI, which uses, respectively, Internal-Tin-Diffusion and Powder-In-Tube methods, with the aim of reaching a non-copper critical current density of ~ 3000 A/mm2 at 12 T and 4.2 K. Characterization results, including critical current and magnetization data, are presented and discussed, as well, for conductors already developed by both companies for this project. SMI succeeded to produce a strand with 50 Ôm diameter filaments and with a critical current of ~ 1400 A at 4.2 K and 12àT, corresponding to a non-copper critical current density of ~ 2500 A/mm2. Cabling trials with this strand were successfully carried out at LBNL
Insertion Magnets
Chapter 3 in High-Luminosity Large Hadron Collider (HL-LHC) : Preliminary
Design Report. The Large Hadron Collider (LHC) is one of the largest scientific
instruments ever built. Since opening up a new energy frontier for exploration
in 2010, it has gathered a global user community of about 7,000 scientists
working in fundamental particle physics and the physics of hadronic matter at
extreme temperature and density. To sustain and extend its discovery potential,
the LHC will need a major upgrade in the 2020s. This will increase its
luminosity (rate of collisions) by a factor of five beyond the original design
value and the integrated luminosity (total collisions created) by a factor ten.
The LHC is already a highly complex and exquisitely optimised machine so this
upgrade must be carefully conceived and will require about ten years to
implement. The new configuration, known as High Luminosity LHC (HL-LHC), will
rely on a number of key innovations that push accelerator technology beyond its
present limits. Among these are cutting-edge 11-12 tesla superconducting
magnets, compact superconducting cavities for beam rotation with ultra-precise
phase control, new technology and physical processes for beam collimation and
300 metre-long high-power superconducting links with negligible energy
dissipation. The present document describes the technologies and components
that will be used to realise the project and is intended to serve as the basis
for the detailed engineering design of HL-LHC.Comment: 19 pages, Chapter 3 in High-Luminosity Large Hadron Collider (HL-LHC)
: Preliminary Design Repor
Status of the Super-B factory Design
The SuperB international team continues to optimize the design of an
electron-positron collider, which will allow the enhanced study of the origins
of flavor physics. The project combines the best features of a linear collider
(high single-collision luminosity) and a storage-ring collider (high repetition
rate), bringing together all accelerator physics aspects to make a very high
luminosity of 10 cm sec. This asymmetric-energy collider
with a polarized electron beam will produce hundreds of millions of B-mesons at
the (4S) resonance. The present design is based on extremely low
emittance beams colliding at a large Piwinski angle to allow very low
without the need for ultra short bunches. Use of crab-waist
sextupoles will enhance the luminosity, suppressing dangerous resonances and
allowing for a higher beam-beam parameter. The project has flexible beam
parameters, improved dynamic aperture, and spin-rotators in the Low Energy Ring
for longitudinal polarization of the electron beam at the Interaction Point.
Optimized for best colliding-beam performance, the facility may also provide
high-brightness photon beams for synchrotron radiation applications
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