47 research outputs found
Segregation by thermal diffusion of an intruder in a moderately dense granular fluid
A solution of the inelastic Enskog equation that goes beyond the weak
dissipation limit and applies for moderate densities is used to determine the
thermal diffusion factor of an intruder immersed in a dense granular gas under
gravity. This factor provides a segregation criterion that shows the transition
between the Brazil-nut effect (BNE) and the reverse Brazil-nut effect (RBNE) by
varying the parameters of the system (masses, sizes, density and coefficients
of restitution). The form of the phase-diagrams for the BNE/RBNE transition
depends sensitively on the value of gravity relative to the thermal gradient,
so that it is possible to switch between both states for given values of the
parameters of the system. Two specific limits are considered with detail: (i)
absence of gravity, and (ii) homogeneous temperature. In the latter case, after
some approximations, our results are consistent with previous theoretical
results derived from the Enskog equation. Our results also indicate that the
influence of dissipation on thermal diffusion is more important in the absence
of gravity than in the opposite limit. The present analysis extends previous
theoretical results derived in the dilute limit case [V. Garz\'o, Europhys.
Lett. {\bf 75}, 521 (2006)] and is consistent with the findings of some recent
experimental results.Comment: 10 figure
EVOALG. Grundlagen und Anwendungen evolutionaerer Algorithmen Abschlussbericht
This report contains the results of the EVOALG group at Humboldt-University which were obtained in collaboration with the Center of Informatics Dortmund (Prof. H. Schwefel) and the Siemens AG (Group Dr. M. Hoehfeldt). In the center is the study of relevant model problems, the classification of optimization problems, applications (in collaboration with the partners). Chapter 1: Structural analysis of sequences. Chapter 2: Classification problems. Chapter 3: New optimization algorithms. Chapter 4: Model problems of structural optimization. Chapter 5: Applications on problems in physics. (orig.)SIGLEAvailable from TIB Hannover: F98B1255+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman
Specific metabolic rates of major organs and tissues across adulthood: evaluation by mechanistic model of resting energy expenditure1234
Background: The specific resting metabolic rates (Ki; in kcal · kg−1 · d−1) of major organs and tissues in adults were suggested by Elia (in Energy metabolism: tissue determinants and cellular corollaries. New York, NY: Raven Press, 1992) to be as follows: 200 for liver, 240 for brain, 440 for heart and kidneys, 13 for skeletal muscle, 4.5 for adipose tissue, and 12 for residual organs and tissues. However, Elia's Ki values have never been fully evaluated
Adiposity and cancer risk: new mechanistic insights from epidemiology
Excess body adiposity, commonly expressed as body mass index (BMI), is a risk factor for many common adult cancers. Over the past decade, epidemiological data have shown that adiposity-cancer risk associations are specific for gender, site, geographical population, histological subtype and molecular phenotype. The biological mechanisms underpinning these associations are incompletely understood but need to take account of the specificities observed in epidemiology to better inform future prevention strategies