4,507 research outputs found
Electromagnetic fields and transport coefficients in a hot pion gas
We present recent results on finite temperature electromagnetic form factors
and the electrical conductivity in a pion gas. The standard Chiral Perturbation
Theory power counting needs to be modified for transport coefficients. We pay
special attention to unitarity and to possible applications for dilepton and
photon production.Comment: 4pp, 2 figures, talk given at "Strong and Electroweak Matter 2006",
BNL, May 200
Transport coefficients of a massive pion gas
We review or main results concerning the transport coefficients of a light
meson gas, in particular we focus on the case of a massive pion gas. Leading
order results according to the chiral power-counting are presented for the DC
electrical conductivity, thermal conductivity, shear viscosity, and bulk
viscosity. We also comment on the possible correlation between the bulk
viscosity and the trace anomaly in QCD, as well as the relation between
unitarity and a minimum of the quotient near the phase transition.Comment: Talk given at the 5th International Conference on Quarks and Nuclear
Physics (QNP09), Beijing, September 21-26, 200
Chiral symmetry and mesons in hot and dense matter: recent developments
We review recent results on properties of the meson gas relevant for Heavy
Ion Collision and Nuclear Matter experiments, within the framework of chiral
lagrangians. In particular, we describe the temperature and density evolution
of the and poles and its connection with chiral symmetry
restoration, as well as the chemical nonequilibrated phase and transport
coefficients.Comment: Proceedings of the "Chiral10 International Workshop on Chiral
Symmetry in Hadrons and Nuclei", Valencia, Spain, 21-24 june 2010. 9 pages, 5
figures. AIP Proceedings styl
ENRICHME integration of ambient intelligence and robotics for AAL
Technological advances and affordability of recent smart sensors, as well as the consolidation of common software platforms for the integration of the latter and robotic sensors, are enabling the creation of complex active and assisted living environments for improving the quality of life of the elderly and the less able people. One such example is the integrated system developed by the European project ENRICHME, the aim of which is to monitor and prolong the independent living of old people affected by mild cognitive impairments with a combination of smart-home, robotics and web technologies. This paper presents in particular the design and technological solutions adopted to integrate, process and store the information provided by a set of fixed smart sensors and mobile robot sensors in a domestic scenario, including presence and contact detectors, environmental sensors, and RFID-tagged objects, for long-term user monitoring an
Minimally invasive decompression in patients with degenerative spondylolisthesis associated with lumbar spinal stenosis. Report of a surgical series and review of the literature
We reported the results of minimally invasive spinal decompression (MISD) in patients with degenerative spondylolisthesis (DS) associated with lumbar spinal stenosis (LSS) and performed a literature review in order to evaluate the clinical and radiological outcomes, the complications and reoperation rate of MISD procedures in these patients.
Data of 28 patients submitted to MISD for DS associated to LSS were reviewed. We evaluated the Visual Analogue Scale (VAS) both for low back pain (LBP) and legs pain, the Oswestry Disability Index (ODI) and the degree of the slippage. A PubMed search of the English literature was conducted. Only papers with more than 10 patients and reporting explicitly data of patients with DS were included in the analysis. We found a statistically significant improvement of LBP, legs pain and ODI in our series. The degree of slippage was stable at follow-up (FU) with no need of reoperation. No major complications occurred. In our literature review, we were able to analyze the differences in ODI in 156 patients and the differences in Japanese Orthopedic Association (JOA) score in 218 patients. We observed a statistically significant improvement of ODI and JOA score at FU compared to pre-operative. The percentage of slippage, evaluated in 283 patients, was unchanged at FU compared to pre-operative. The overall complication rate was 1.6%. The overall reoperation rate was 4.5%.
MISD procedures are safe and effective in patients with DS associated to LSS and are associated to low morbidity and significant improvement of disability without progression of slippage
Energy sustainable paradigms and methods for future mobile networks: A survey
In this survey, we discuss the role of energy in the design of future mobile
networks and, in particular, we advocate and elaborate on the use of energy
harvesting (EH) hardware as a means to decrease the environmental footprint of
5G technology. To take full advantage of the harvested (renewable) energy,
while still meeting the quality of service required by dense 5G deployments,
suitable management techniques are here reviewed, highlighting the open issues
that are still to be solved to provide eco-friendly and cost-effective mobile
architectures. Several solutions have recently been proposed to tackle
capacity, coverage and efficiency problems, including: C-RAN, Software Defined
Networking (SDN) and fog computing, among others. However, these are not
explicitly tailored to increase the energy efficiency of networks featuring
renewable energy sources, and have the following limitations: (i) their energy
savings are in many cases still insufficient and (ii) they do not consider
network elements possessing energy harvesting capabilities. In this paper, we
systematically review existing energy sustainable paradigms and methods to
address points (i) and (ii), discussing how these can be exploited to obtain
highly efficient, energy self-sufficient and high capacity networks. Several
open issues have emerged from our review, ranging from the need for accurate
energy, transmission and consumption models, to the lack of accurate data
traffic profiles, to the use of power transfer, energy cooperation and energy
trading techniques. These challenges are here discussed along with some
research directions to follow for achieving sustainable 5G systems.Comment: Accepted by Elsevier Computer Communications, 21 pages, 9 figure
47-fs Kerr-lens mode-locked Cr:ZnSe laser with high spectral purity
We report on a room-temperature Kerr-lens mode-locked Cr:ZnSe femtosecond laser operating at around 2.4 Ôm emission wavelength. Self-starting nearly transform-limited pulse trains with a minimum duration of 47 fs, corresponding to six optical cycles, and average output power of 0.25 W are obtained with repetition frequencies in the range from 140 to 300 MHz. The femtosecond pulse train is characterized by high-spectral purity and low time jitter
Properties of light resonances from unitarized Chiral perturbation theory: Nc behavior and quark mass dependence
We review the unitarization of Chiral Perturbation Theory with dispersion
relations and how it describes meson-meson scattering data, generating light
resonances whose mass, width and nature can be related to QCD parameters like
quark masses and the number of colors.Comment: Invited review talk for the New Frontiers in QCD 2010, Yukawa
International Program for Quark-Hadron Sciences (YIPQS), January 18 (Mon) -
March 19 (Fri), 2010 Yukawa Institute for Theoretical Physics, Kyoto, Japan.
To appear in Progress of Theoretical Physic
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