We consider a polymer, with monomer locations modeled by the trajectory of an underlying Markov chain, in the presence of a potential that interacts with the polymer when it visits a particular site 0. Disorder is introduced by having the interaction vary from one monomer to another, as a constant u plus i.i.d. mean-0 randomness. There is a critical value of u above which the polymer is pinned,...

The jamming transition in granular packings is characterized by a sudden change in the coordination number. In this work we investigate the evolution of coordination number as function of volume fraction for frictionless packings of spheres undergoing isotropic deformation. Using the results obtained from Discrete Element Method simulations, we confirm that the coordination number depends on vo...

Although bone strength and modulus are known to be influenced by both volume fraction and mineral content (ash fraction), the relative influence of these two parameters remains unknown. Single-parameter power law functions are used widely to relate bone volume or ash fraction to bone strength and elastic modulus. In this study we evaluate the potential for predicting bone mechanical properties ...

the main purpose of this study is to perform numerical simulation of nanofluids as the coolant in vver-440 fuel rod bundle. the fuel rod bundle contains 60 fuel rods with length of 960 mm and 4 spacer grids. in vver-440 fuel rod bundle the coolant fluid (water) is in high pressure and temperature condition. in the present thermo-hydraulic simulation, water-al2o3 nanofluids containing various vo...

introduction: we investigated the difference in left ventricular ejection fraction (lvef) and end-systolic volume(esv) measured by gated myocardial perfusion spect (gspect) in the post-dipyridamole stress and rest periods, and compared the results with the perfusion patterns found in the conventional non-gated tomograms. methods: 297 consecutive patients were studied with post-stress and rest 9...

A series of experiments was carried out using a dual sensor conductance probe to measure the local axial oil velocity distribution and the local oil volume fraction distribution in vertical, oil in water bubbly flows in an 80mm diameter vertical pipe. Values of the water superficial velocity were in the range 0.276 1 ms to 0.417 1 ms , values of the oil superficial velocity were in the range 0....

We use a momentum balance to interpret numerical simulations of dense, steady, fully-developed inclined granular flows of spheres on an erodible base confined between flat frictional side walls. We observe an exponential profile of mean volume fraction in the direction perpendicular to the base and suggest a scaling for its characteristic length. We also predict volume fraction and mean velocit...

It was recently pointed out that the distribution of times between solar flares (the flare waiting-time distribution) follows a power law for long waiting times. Based on 25 years of soft X-ray flares observed by Geostationary Operational Environmental Satellite instruments, it is shown that (1) the waiting-time distribution of flares is consistent with a time-dependent Poisson process and (2) ...

Starting with an expression, due originally to Einstein, for the shear viscosity η(δφ) of a liquid having a small fraction δφ by volume of solid particulate matter suspended in it at random, we derive an effective-medium viscosity η(φ) for arbitrary φ which is precisely of the Vogel-Fulcher form. An essential point of the derivation is the incorporation of the excluded-volume effect at each tur...

The observed number density of Lyman-α sources implies a minimum volume of the inter-galactic medium that must be ionized, in order to allow the Lyman-α photons to escape attenuation. We estimate this volume by assigning to each Lyman-α emitter the minimum Stromgren sphere that would allow half its Lyman-α photons to escape. This implies a lower limit to ionized gas volume fraction of 20-50% at...