12,560 research outputs found
Upgrades of the ATLAS Muon Spectrometer with sMDT Chambers
With half the drift-tube diameter of the Monitored Drift Tube (MDT) chambers
of the ATLAS muon spectrometer and otherwise unchanged operating parameters,
small-diameter Muon Drift Tube (sMDT) chambers provide an order of magnitude
higher rate capability and can be installed in detector regions where MDT
chambers do not fit. The chamber assembly time has been reduced by a factor of
seven to one working day and the sense wire positioning accuracy improved by a
factor of two to better than ten microns. Two sMDT chambers have been installed
in ATLAS in 2014 to improve the momentum resolution in the barrel part of the
spectrometer. The construction of an additional twelve chambers covering the
feet regions of the ATLAS detector has started. It will be followed by the
replacement of the MDT chambers at the ends of the barrel inner layer by sMDTs
improving the Performance at the high expected background rates and providing
space for additional RPC trigger chambers
Acoustic measurement of the low-energy excitations in Nd2-xCexCuO4
The complex dynamic Young's modulus of ceramic Nd2-xCexCuO4 with x = 0, 0.05
and 0.20 has been measured from 1.5 to 100 K at frequencies of 1-10 kHz. In the
undoped sample the modulus starts decreasing below ~20 K, instead of
approaching a constant value as in a normal solid. The modulus minimum has been
interpreted in terms of paraelastic contribution from the relaxation of the
Nd^3+ 4f electrons between the levels of the ground state doublet, which is
split by the interaction with the antiferromagnetically ordered Cu sublattice.
The value of the splitting is found to be 0.34 meV, in excellent agreement with
inelastic neutron scattering, infrared and specific heat experiments. With
doping, the anomaly shifts to lower temperature and decreases in amplitude,
consistently with a reduction of the local field from the Cu sublattice.Comment: 5 pages, 2 figures, submitted to Eur. Phys. J.
A Novel Ultrasound-based Measure of the Liver among Diabetes Mellitus Type II Patients
Diabetes mellitus type II (DM II) or adult onset diabetes is due to the inefficient use of insulin, which affects various organs and tissues. Patients with DM II are at risk of suffering non-alcoholic fatty liver disease (NAFLD) that can later develop into more life threating forms such as hepatomegaly, cirrhosis or liver cancer. Following the logic of the non-inferiority trial test, we aim to establish a more accurate anatomical measure of the right liver lobe (RLL) to facilitate close monitoring of liver size with ultrasound (US). We hypothesize that US is not unacceptably worse than computed tomography (CT) or magnetic resonance imaging (MRI) to accurately and reliably measure the size of the RLL when the measure is taken in the midaxillary line and craniocaudal plane (MAL-CC). Therefore, the objective of this study is to conduct a non-inferiority trial to test our novel MAL-CC measure.
To meet this aim, US measure of the RLL was taken from DM II (n=7) and non-DM II (n=5) patients, whom were recruited from 2 endocrinology clinics at SoM-UPR. Preliminary data shows that MAL-CC measure of the RLL from non-DM II patients is 13.99 + 2.53 cm whereas the same measurement among DM II patients is 15.25 + 3.25 cm (Mann-Whitney U test, p= 0.42). It is concluded that there is a non-significant trend for large RLL sizes among DM II patients. Future work aims to increase sample size and to validate our novel measurement with MRI
On the Complex Network Structure of Musical Pieces: Analysis of Some Use Cases from Different Music Genres
This paper focuses on the modeling of musical melodies as networks. Notes of
a melody can be treated as nodes of a network. Connections are created whenever
notes are played in sequence. We analyze some main tracks coming from different
music genres, with melodies played using different musical instruments. We find
out that the considered networks are, in general, scale free networks and
exhibit the small world property. We measure the main metrics and assess
whether these networks can be considered as formed by sub-communities. Outcomes
confirm that peculiar features of the tracks can be extracted from this
analysis methodology. This approach can have an impact in several multimedia
applications such as music didactics, multimedia entertainment, and digital
music generation.Comment: accepted to Multimedia Tools and Applications, Springe
Non-neutral theory of biodiversity
We present a non-neutral stochastic model for the dynamics taking place in a
meta-community ecosystems in presence of migration. The model provides a
framework for describing the emergence of multiple ecological scenarios and
behaves in two extreme limits either as the unified neutral theory of
biodiversity or as the Bak-Sneppen model. Interestingly, the model shows a
condensation phase transition where one species becomes the dominant one, the
diversity in the ecosystems is strongly reduced and the ecosystem is
non-stationary. This phase transition extend the principle of competitive
exclusion to open ecosystems and might be relevant for the study of the impact
of invasive species in native ecologies.Comment: 4 pages, 3 figur
Cloud for Gaming
Cloud for Gaming refers to the use of cloud computing technologies to build
large-scale gaming infrastructures, with the goal of improving scalability and
responsiveness, improve the user's experience and enable new business models.Comment: Encyclopedia of Computer Graphics and Games. Newton Lee (Editor).
Springer International Publishing, 2015, ISBN 978-3-319-08234-
The Silurian of Sardinia
The present volume “The Silurian of Sardinia” is composed of two related components. The first part comprises seven contributions introduced by an historical overview on the studies already carried out on the Silurian faunas of Sardinia. It aims to delineate a comprehensive scenario of the Silurian of Sardinia within a proper geological setting. A global overview regarding the palaeoenvironment and palaeogeography is also provided. The second part of the volume consists of seven research papers that illustrate actual knowledge on major fossil groups encountered in the Silurian limestones and shales of southern Sardinia
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