Tracer-diffusion of small molecules through dense systems of chain polymers is studied within an athermal lattice model, where hard-core interactions are taken into account by means of the site exclusion principle. An approximate mapping of this problem onto dynamic percolation theory is proposed. This method is shown to yield quantitative results for the tracer correlation factor of the molecu...

ABSTRACT We introduce a method to infer the vertical distribution of stars in Milky Way using Poisson likelihood function, with view applying our Gaia catalogue. show how account for sample selection function and parallax measurement uncertainties. Our is validated against simulated drawn from model two exponential discs power-law halo profile. A mock generated astrometry whilst realistic uncer...

The transverse velocities of steadily rotating, non–axisymmetric patterns in flat galaxies may be determined by a purely kinematical method, using two dimensional maps of a tracer surface brightness and radial current density. The data–maps could be viewed as the zeroth and first velocity moments of the line–of–sight velocity distribution, which is the natural output of integral– field spectrog...

The dynamics and the steady states of a point-like tracer particle immersed in confined critical fluid are studied. is modeled field-theoretically terms an order parameter (concentration or density field) obeying dissipative conservative equilibrium (non-)symmetry-breaking boundary conditions. tracer, which represents, e.g., colloidal particle, interacts with by locally modifying its chemical p...

Electrical imaging of tracer tests can provide valuable information on the spatial variability of solute transport processes. This concept was investigated by cross-borehole electrical imaging of a controlled release in an experimental tank. A saline Ž 3 . Ž . tracer conductivity 8=10 msrm volume 270 l was injected into a tank facility dimensions 10=10=3 m consisting of alternating sand and cla...

Diffusive motion of particles plays an important role in many phenomena in surface physics, for example in chemical reactions, surface growth, and spreading. Diffusive motion can be observed in many different systems. In this thesis we study diffusion and dynamics in two fundamentally different kinds of systems: (i) in Brownian surface systems, and (ii) in a nonBrownian system of sedimenting pa...

Recent evidence indicates that the rat claustrum interconnects the motor cortical areas in both hemispheres. To elucidate the functional specificity of the interhemispheric connections between the claustrum and primary motor (MI) cortex, anterograde tracer injections in specific parts of MI were paired with retrograde tracer injections in homotopic sites of the opposite hemisphere. In addition ...

Zero-valent iron nanoparticles (INP) were synthesized and stabilized using poly acrylic acid (PAA) to yield stabilized INP (S-INP). A two-dimensional physical model was used to study the fate and transport of the INP and S-INP in porous media under saturated, steady-state flow conditions. Transport data for a nonreactive tracer, INP, and S-INP were collected under similar flow conditions. The r...

The Z-pinch dynamic hohlraum is an x-ray source for high energy-density physics studies that is heated by a radiating shock to radiation temperatures >200 eV. The time-dependent 300-400 eV electron temperature and 15-35 mg/cc density of this shock have been measured for the first time using space-resolved Si tracer spectroscopy. The shock x-ray emission is inferred from these measurements to ex...

UNLABELLED Accelerated cardiac washout of (123)I-metaiodobenzylguanidine (MIBG), which is clinically used as an index of cardiac neuropathy in diabetes, is ascribed to decreased norepinephrine reuptake into synaptic vesicles. However, accelerated washout frequently contrasts with preserved early tracer uptake, whose significance remains undetermined. The aim of this study was to investigate in ...