2,569 research outputs found
A Novel Generic Framework for Track Fitting in Complex Detector Systems
This paper presents a novel framework for track fitting which is usable in a
wide range of experiments, independent of the specific event topology, detector
setup, or magnetic field arrangement. This goal is achieved through a
completely modular design. Fitting algorithms are implemented as
interchangeable modules. At present, the framework contains a validated Kalman
filter. Track parameterizations and the routines required to extrapolate the
track parameters and their covariance matrices through the experiment are also
implemented as interchangeable modules. Different track parameterizations and
extrapolation routines can be used simultaneously for fitting of the same
physical track. Representations of detector hits are the third modular
ingredient to the framework. The hit dimensionality and orientation of planar
tracking detectors are not restricted. Tracking information from detectors
which do not measure the passage of particles in a fixed physical detector
plane, e.g. drift chambers or TPCs, is used without any simplifications. The
concept is implemented in a light-weight C++ library called GENFIT, which is
available as free software
Low-velocity impact behaviour of fibreglass-aluminium laminates
Low-velocity impact tests were performed on fibreglassâaluminium composites made of 2024 T3 sheets and S2-glass/epoxy prepreg layers, using an instrumented falling weight machine. For comparison purposes, similar tests were carried out on monolithic 2024 T3 sheets of equivalent thickness. In the tests, the impact speed, mass, and energy were varied, to ascertain the influence of these parameters on the material response. From the results obtained, the overall forceâdisplacement curve only depends on the impact energy, rather than on the mass and speed separately. Further, the energy required for penetration is higher for monolithic aluminium than for the fibreglassâ aluminium. However, the latter material seems to offer better performance than carbon fibre- and glass fibre-reinforced laminates in terms of penetration energy, damage resistance, and inspectability. The main failure modes of fibreglass â aluminium were assessed by both ultrasonic C-scan and chemical grinding of aluminium sheets. It was found that the energy required for first failure is very low, whereas the energy level resulting in first fibre failure is similar to that inducing first cracking in the 2024 T3 sheets. From the experimental data, simple empirical relationships were found for the calculation of maximum contact force, energy, and residual displacement as a function of the maximum displacement
A Comparison of a Brain-Computer Interface and an Eye Tracker: Is There a More Appropriate Technology for Controlling a Virtual Keyboard in an ALS Patient?
The ability of people affected by amyotrophic lateral sclerosis (ALS), muscular dystrophy or spinal cord injuries to physically interact with the environment, is usually reduced. In some cases, these patients suffer from a syndrome known as locked-in syndrome (LIS), defined by the patientâs inability to make any move-ment but blinks and eye movements. Tech communication systems available for people in LIS are very limited, being those based on eye-tracking and brain-computer interface (BCI) the most useful for these patients. A comparative study between both technologies in an ALS patient is carried out: an eye tracker and a visual P300-based BCI. The purpose of the study presented in this paper is to show that the choice of the technology could depend on userÂŽs preference. The evaluation of performance, workload and other subjective measures will allow us to determine the usability of the systems. The obtained results suggest that, even if for this patient the BCI technology is more appropriate, the technology should be always tested and adapted for each user.Universidad de MĂĄlaga. Campus de Excelencia Internacional AndalucĂa Tech
TRACHEOSTOMY MECHANICAL VENTILATION IN PATIENTS WITH AMYOTROPHIC LATERAL SCLEROSIS: CLINICAL FEATURES AND SURVIVAL ANALYSIS.
Background: Tracheostomy mechanical ventilation (TMV) is performed in amyotrophic lateral sclerosis (ALS)
patients with a respiratory failure or when the non-invasive ventilation (NIV) is no longer effective. We
evaluated the clinical characteristics and survival of a cohort of tracheostomized ALS patients, followed in a
single ALS Clinical Center.
Methods: Between 2001 and 2010, 87 out of 279 ALS patients were submitted to TMV. Onset was spinal in 62
and bulbar in 25. After tracheostomy, most patients were followed up through telephone interviews to
caregivers. A complete survival analysis could be performed in fifty-two TMV patients.
Results: 31.3% ALS patients underwent tracheostomy, with a male prevalence (M/F=1.69) and a median age
of 61 years (interquartile range=47â66). After tracheostomy, nearly all patients were under home care.
TMV ALS patients were more likely than non-tracheostomized (NT) patients to be implanted with a PEG device,
although the bulbar-/spinal-onset ratio did not differ between the two groups. KaplanâMeyer analysis
showed that tracheostomy increases median survival (TMV, 47 months vs NT, 31 months, p=0.008), with
the greatest effect in patients younger than 60 at onset (TMVâ€60 years, 57.5 months vs NTâ€60 years,
38.5 months, p=0.002).
Conclusions: TMV is increasingly performed in ALS patients. Nearly all TMV patients live at home and most of
them are fed through a PEG device. Survival after tracheostomy is generally increased, with the stronger
effect in patients younger than 60. This survival advantage is apparently lost when TMV is performed in
patients older than 60. The results of this study might be useful for the decision-making process of patients
and their families about this advanced palliative care
Parallel Genetic Algorithms for calibrating Cellular Automata models: Application to lava flows
Cellular Automata are highly nonlinear dynamical systems which are suitable for simulating natural phenomena whose behaviour may be specified in terms of local interactions. The Cellular Automata model SCIARA, developed for the simulation of lava flows, demonstrated to be able to reproduce the behaviour of Etnean events. However, in order to apply the model for the prediction of future scenarios,
a thorough calibrating phase is required. This work presents the application of Genetic Algorithms,
general-purpose search algorithms inspired to natural selection and genetics, for the parameters optimisation of the modelSCIARA. Difficulties due to the elevated computational time suggested the adoption a Master-Slave Parallel Genetic Algorithm for the calibration of the model with respect to the 2001 Mt. Etna eruption. Results demonstrated the usefulness of the approach, both in terms of computing time and quality of performed simulations
Molybdenum sputtering film characterization for high gradient accelerating structures
Technological advancements are strongly required to fulfill the demands of
new accelerator devices with the highest accelerating gradients and operation
reliability for the future colliders. To this purpose an extensive R&D
regarding molybdenum coatings on copper is in progress. In this contribution we
describe chemical composition, deposition quality and resistivity properties of
different molybdenum coatings obtained via sputtering. The deposited films are
thick metallic disorder layers with different resistivity values above and
below the molibdenum dioxide reference value. Chemical and electrical
properties of these sputtered coatings have been characterized by Rutherford
backscattering, XANES and photoemission spectroscopy. We will also present a
three cells standing wave section coated by a molybdenum layer 500 nm
thick designed to improve the performance of X-Band accelerating systems.Comment: manuscript has been submitted and accepted by Chinese Physics C
(2012
[68 Ga]DOTATOC PET/CT Radiomics to Predict the Response in GEP-NETs Undergoing [177 Lu]DOTATOC PRRT: The âTheragnomicsâ Concept
Assessment of body fluid balance and voluntary drinking in ultimate players during a match.
AIM: Ultimate is a sport played by hundreds of thousands of people in more than 42 countries; however, it is still mainly known as a recreational more than a team sport, and further studies are needed to define its physical load.
Particularly, since no studies relating Ultimate to hydration have been performed, we aimed to determine body fluid balance, voluntary water intake and the most reliable method for assessing the hydration status of players after a
typical 80-minute Ultimate match.
METHODS: bioimpedance, urine specific gravity and body mass changes to asses the hydration level of the players were measured.
RESULTS: It was observed that not all of the methods are adequate to determine dehydration in Ultimate players, and that measurement of body mass changes represents a reliable and accurate technique.
CONCLUSIONS: These findings demonstrate that ultimate as an intense sport that can induce significant fluid loss, which is not always replaced by individual drinking
Progress on the hybrid gun project at UCLA
UCLA/INFN-LNF/Univ. Rome has been developing the hybrid gun which has an RF gun and a short linac for velocity bunching in one structure. After the cavity was manufactured at INFN-LNF in 2012, tests of the gun was carried out at UCLA. The field in the standing wave part was 20 % smaller than the simulation but the phase advance was fine. The cavity was commissioned successfully up to 13 MW. The beam test was performed at 11.5 MW and demonstrated the bunch compression
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