3,710 research outputs found
The equation of state in lattice QCD: with physical quark masses towards the continuum limit
The equation of state of QCD at vanishing chemical potential as a function of
temperature is determined for two sets of lattice spacings. Coarser lattices
with temporal extension of N_t=4 and finer lattices of N_t=6 are used. Symanzik
improved gauge and stout-link improved staggered fermionic actions are applied.
The results are given for physical quark masses both for the light quarks and
for the strange quark. Pressure, energy density, entropy density, quark number
susceptibilities and the speed of sound are presented.Comment: 14 pages, 9 figures. Version published in JHEP: discussions added in
Sects. 1, 2. Fig. 1 changed and a new figure for the interaction measure
added. Information on statistics added in Table 1. Raw values of the pressure
added in Table 3. A few references adde
Managing Access to Biobanks:How Can We Reconcile Privacy and Public Interests in Genetic Research?
This article is concerned with the ultimate objectives of genetic biobanks set up to promote the public interest—being the sharing of samples and data for medical research—and the consequences for personal privacy of realising them. Our aim is to chart the values, interests and principles in play, to consider the challenges of realizing biobanking objectives on a global scale, and to propose viable ways forward that ensure, as far as possible, that access provisions remain fit for purpose throughout the entire life of a biobank, while adequately protecting the privacy interests at stake. It is argued that key features in any robust access model must include mechanisms to (a) maintain participant trust in management of the resource and to measure and respond to participants’ expectations, (b) facilitate and promote the sharing of benefits, and (c) respond timeously and effectively to new challenges
Analysis and design of a capsule landing system and surface vehicle control system for Mars exploration
Problems related to the design and control of an autonomous rover for the purpose of unmanned exploration of the planets were considered. Building on the basis of prior studies, a four wheeled rover of unusual mobility and maneuverability was further refined and tested under both laboratory and field conditions. A second major effort was made to develop autonomous guidance. Path selection systems capable of dealing with relatively formidable hazard and terrains involving various short range (1.0-3.0 meters), hazard detection systems using a triangulation detection concept were simulated and evaluated. The mechanical/electronic systems required to implement such a scheme were constructed and tested. These systems include: laser transmitter, photodetectors, the necessary data handling/controlling systems and a scanning mast. In addition, a telemetry system to interface the vehicle, the off-board computer and a remote control module for operator intervention were developed. Software for the autonomous control concept was written. All of the systems required for complete autonomous control were shown to be satisfactory except for that portion of the software relating to the handling of interrupt commands
Analysis and design of a capsule landing system and surface vehicle control system for Mars exploration
Problems related to an unmanned exploration of the planet Mars by means of an autonomous roving planetary vehicle are investigated. These problems include: design, construction and evaluation of the vehicle itself and its control and operating systems. More specifically, vehicle configuration, dynamics, control, propulsion, hazard detection systems, terrain sensing and modelling, obstacle detection concepts, path selection, decision-making systems, and chemical analyses of samples are studied. Emphasis is placed on development of a vehicle capable of gathering specimens and data for an Augmented Viking Mission or to provide the basis for a Sample Return Mission
Analysis and design of a capsule landing system and surface vehicle control system for Mars exploration
Problems related to the design and control of a mobile planetary vehicle to implement a systematic plan for the exploration of Mars are reported. Problem areas include: vehicle configuration, control, dynamics, systems and propulsion; systems analysis, terrain modeling and path selection; and chemical analysis of specimens. These tasks are summarized: vehicle model design, mathematical model of vehicle dynamics, experimental vehicle dynamics, obstacle negotiation, electrochemical controls, remote control, collapsibility and deployment, construction of a wheel tester, wheel analysis, payload design, system design optimization, effect of design assumptions, accessory optimal design, on-board computer subsystem, laser range measurement, discrete obstacle detection, obstacle detection systems, terrain modeling, path selection system simulation and evaluation, gas chromatograph/mass spectrometer system concepts, and chromatograph model evaluation and improvement
QCD thermodynamics with continuum extrapolated Wilson fermions II
We continue our investigation of 2+1 flavor QCD thermodynamics using
dynamical Wilson fermions in the fixed scale approach. Two additional pion
masses, approximately 440 MeV and 285 MeV, are added to our previous work at
545 MeV. The simulations were performed at 3 or 4 lattice spacings at each pion
mass. The renormalized chiral condensate, strange quark number susceptibility
and Polyakov loop is obtained as a function of the temperature and we observe a
decrease in the light chiral pseudo-critical temperature as the pion mass is
lowered while the pseudo-critical temperature associated with the strange quark
number susceptibility or the Polyakov loop is only mildly sensitive to the pion
mass. These findings are in agreement with previous continuum results obtained
in the staggered formulation.Comment: 19 pages, 13 figures, published versio
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