304 research outputs found
Zeroth Law compatibility of non-additive thermodynamics
Non-extensive thermodynamics was criticized among others by stating that the
Zeroth Law cannot be satisfied with non-additive composition rules. In this
paper we determine the general functional form of those non-additive
composition rules which are compatible with the Zeroth Law of thermodynamics.
We find that this general form is additive for the formal logarithms of the
original quantities and the familiar relations of thermodynamics apply to
these. Our result offers a possible solution to the longstanding problem about
equilibrium between extensive and non-extensive systems or systems with
different non-extensivity parameters.Comment: 18 pages, 1 figur
How much is your diet? (Estimation about prices of “traditional Hungarian”, diabetic, low energy diets, and related life-style expenses)
Nutrition and lifestyle-related diseases are some of the leading morbidities among the Hungarian population. People who want to lose weight often complain that healthy diet is expensive.
Our aim was to quantify the costs of three different types of diet for a three-day period. We compared “traditional Hungarian”, low energy, and diabetic diets, considering both energy content and expenses related to lifestyle.
According to our estimation: diabetic (including medication) and ”traditional” Hungarian diets were the most expensive. Low energy diet proved to be the most cost-effective despite the extra expenditures of higher physical activity
Different sensing mechanisms in single wire and mat carbon nanotubes chemical sensors
Chemical sensing properties of single wire and mat form sensor structures
fabricated from the same carbon nanotube (CNT) materials have been compared.
Sensing properties of CNT sensors were evaluated upon electrical response in
the presence of five vapours as acetone, acetic acid, ethanol, toluene, and
water. Diverse behaviour of single wire CNT sensors was found, while the mat
structures showed similar response for all the applied vapours. This indicates
that the sensing mechanism of random CNT networks cannot be interpreted as a
simple summation of the constituting individual CNT effects, but is associated
to another robust phenomenon, localized presumably at CNT-CNT junctions, must
be supposed.Comment: 12 pages, 5 figures,Applied Physics A: Materials Science and
Processing 201
Strange hyperon and antihyperon production from quark and string-rope matter
Hyperon and antihyperon production is investigated using two microscopical
models: {\bf (1)} the fast hadronization of quark matter as given by the ALCOR
model; {\bf (2)} string formation and fragmentation as in the HIJING/B model.
We calculate the particle numbers and momentum distributions for Pb+Pb
collisions at CERN SPS energies in order to compare the two models with each
other and with the available experimental data. We show that these two
theoretical approaches give similar yields for the hyperons, but strongly
differ for antihyperons.Comment: 11 pages, Latex, 3 EPS figures, contribution to the Proceedings of
the 4th International Conference on Strangeness in Quark Matter (SQM'98),
Padova, Italy, 20-24 July 199
Paired and altruistic kidney donation in the UK: algorithms and experimentation
We study the computational problem of identifying optimal
sets of kidney exchanges in the UK. We show how to expand an integer
programming-based formulation [1, 19] in order to model the criteria that
constitute the UK definition of optimality. The software arising from this
work has been used by the National Health Service Blood and Transplant
to find optimal sets of kidney exchanges for their National Living Donor
Kidney Sharing Schemes since July 2008.We report on the characteristics
of the solutions that have been obtained in matching runs of the scheme
since this time. We then present empirical results arising from the real
datasets that stem from these matching runs, with the aim of establishing
the extent to which the particular optimality criteria that are present
in the UK influence the structure of the solutions that are ultimately
computed. A key observation is that allowing 4-way exchanges would be
likely to lead to a significant number of additional transplants
Density Fluctuations in the Quark-Gluon Plasma
Using the kinetic theory we discuss how the particle and energy densities of
the quark-gluon plasma fluctuate in a space-time cell. The fluctuations in the
equilibrium plasma and in that one from the early stage of ultrarelativistic
heavy-ion collisions are estimated. Within the physically interesting values of
the parameters involved the fluctuations appear sizeable in both cases.Comment: 8 pages, no macro
Effect of the disorder in graphene grain boundaries: A wave packet dynamics study
Chemical vapor deposition (CVD) on Cu foil is one of the most promising methods to produce graphene samples despite of introducing numerous grain boundaries into the perfect graphene lattice. A rich variety of GB structures can be realized experimentally by controlling the parameters in the CVD method. Grain boundaries contain non-hexagonal carbon rings (4, 5, 7, 8 membered rings) and vacancies in various ratios and arrangements. Using wave packet dynamic (WPD) simulations and tight-binding electronic structure calculations, we have studied the effect of the structure of GBs on the transport properties. Three model GBs with increasing disorder were created in the computer: a periodic 5-7 GB, a "serpentine" GB, and a disordered GB containing 4, 8 membered rings and vacancies. It was found that for small energies (E = EF ± 1 eV) the transmission decreases with increasing disorder. Four membered rings and vacancies are identified as the principal scattering centers. Revealing the connection between the properties of GBs and the CVD growth method may open new opportunities in the graphene based nanoelectronics. © 2013 Elsevier B.V. All rights reserved
Near-thermal equilibrium with Tsallis distributions in heavy ion collisions
Hadron yields in high energy heavy ion collisions have been fitted and
reproduced by thermal models using standard statistical distributions. These
models give insight into the freeze-out conditions at varying beam energies. In
this paper we investigate changes to this analysis when the statistical
distributions are replaced by Tsallis distributions for hadrons. We investigate
the appearance of near-thermal equilibrium state at SPS and RHIC energies. We
obtain better fits with smaller chi^2 for the same hadron data, as applied
earlier in the thermal fits for SPS energies but not for RHIC energies. This
result indicates that at RHIC energies the final state is very well described
by a single freeze-out temperature with very little room for fluctuations.Comment: 8 pages, 6 figure
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