36 research outputs found
Work and heat probability distributions in out-of-equilibrium systems
We review and discuss the equations governing the distribution of work done
on a system which is driven out of equilibrium by external manipulation, as
well as those governing the entropy flow to a reservoir in a nonequilibrium
system. We take advantage of these equations to investigate the path phase
transition in a manipulated mean-field Ising model and the large-deviation
function for the heat flow in the asymmetric exclusion process with
periodically varying transition probabilities.Comment: Contribution to Proceedings of "Work, Dissipation, and Fluctuations
in Nonequilibrium Physics", Brussels, 200
Experimental Validation of Critical Heat Flux (CHF) Predictive Methods for a New Synthetic fluid with Low Environmental Impact
Abstract This work presents experimental critical heat flux (CHF) values for a low environmental impact synthetic refrigerant and their comparison with well-known correlations from scientific literature. Tests were performed with HFO-1234yf in an aluminum heat sink made up of seven mini-channels, each of them 2 mm wide and 1 mm high. The heated length was 25 mm. Experiments have been obtained in a variety of thermodynamic condition: the R1234yf saturation temperatures T sat ranged from 25 up to 65 °C (corresponding to medium-to-high reduced pressures), whilst the mass fluxes G had been fixed to 150 up to 300 kg/m 2 s. The tests have been carried out by increasing the heat dissipated by the boiling refrigerant until the thermal crisis occurred and the corresponding heat flux value was recorded as CHF. The experimental results were finally compared to the well-known correlations of Wojtan et al. [1] , Kuan [2] , Katto-Ohno [3] , Zhang et al. [4] and Anwar et al. [5] to investigate their effectiveness with the present data. The latter correlation was found to better predict the experimental values
Chondromyxoid Fibroma of the Lateral Malleolus: A Case Report
Chondromyxoid fibromas account for <1% of primary bone neoplasms. We report one such case occurring in the distal fibula of a 27-year-old woman. The patient underwent curettage, followed by phenolisation, insertion of a Steinmann pin, and cementation. This treatment reduced morbidity, restored stability, and enabled rapid functional recovery. There was no recurrence after 2 years
Intra-articular hyaluronic acid vs platelet-rich plasma in the treatment of hip osteoarthritis
Heat release by controlled continuous-time Markov jump processes
We derive the equations governing the protocols minimizing the heat released
by a continuous-time Markov jump process on a one-dimensional countable state
space during a transition between assigned initial and final probability
distributions in a finite time horizon. In particular, we identify the
hypotheses on the transition rates under which the optimal control strategy and
the probability distribution of the Markov jump problem obey a system of
differential equations of Hamilton-Bellman-Jacobi-type. As the state-space mesh
tends to zero, these equations converge to those satisfied by the diffusion
process minimizing the heat released in the Langevin formulation of the same
problem. We also show that in full analogy with the continuum case, heat
minimization is equivalent to entropy production minimization. Thus, our
results may be interpreted as a refined version of the second law of
thermodynamics.Comment: final version, section 2.1 revised, 26 pages, 3 figure
Mortality from cirrhosis and hepatocellular carcinoma in Western Europe over the last 40Â years
Background & Aims: Cirrhosis (LC) and hepatocellular carcinoma (HCC) are highly prevalent in Europe, with accompanying high mortality rates and social costs. As epidemiological data on these diseases are scarce, age-standardized death rate (ASDR) can serve as an indirect assessment of their burden. Methods: We analysed the ASDRs for LC and HCC from data reported in the WHO official death registries from 1970 to 2010, and compared ASDRs over the decades. The European Detailed Mortality Database was also used as source of data. Results: In 1970, Portugal had the highest reported mortality for LC, followed by France and Italy. However, in 2010, Finland, Austria and Germany were respectively the three highest, while the UK showed the highest increase over those four decades (+284.8%). The annual ASDRs for LC have dropped in Europe from 20.4/105 inhabitants in 1970 to 9.6 in 2010; a 53% decrease. For HCC, Spain, Italy and Denmark were ranked first through third, while in 2010 Italy, France and Luxembourg replaced them. Portugal had the highest increase (+654.7%). In 1980-2010, the ASDR for HCC in Europe increased from 3.4/105 inhabitants to 6.3, up 85.4%. In the majority of nations—except for the UK, Finland and Ireland—there was a decrease in LC mortality and an increase for HCC mortality. Conclusions: The LC mortality rate is decreasing in Europe, yet there is a significant increase in HCC mortality. This phenomenon requires greater attention so we can understand the risk factors and implement preventive measures
Chondromyxoid Fibroma of the Lateral Malleolus: A Case Report
Chondromyxoid fibromas account for <1% of primary bone neoplasms. We report one such case occurring in the distal fibula of a 27-year-old woman. The patient underwent curettage, followed by phenolisation, insertion of a Steinmann pin, and cementation. This treatment reduced morbidity, restored stability, and enabled rapid functional recovery. There was no recurrence after 2 years