Toward a relativistic microscopic substantiation of thermodynamics: classical relativistic many-particle dynamics

An exact closed relativistic kinetic equation is derived for a system of identical classical particles interacting with each other through a scalar field. The law of variation of the energy of a system of particles in terms of the microscopic distribution function is obtained.

Complete polarization of electronic spins in OLEDs

At low temperatures and high magnetic fields, electron and hole spins in an organic light-emitting diode become polarized so that recombination preferentially forms molecular triplet excited-state species. For low device currents, magnetoelectroluminescence perfectly follows Boltzmann activation, implying a virtually complete polarization outcome. As the current increases, the magnetoelectroluminescence effect is reduced because spin polarization is suppressed by the reduction in carrier residence time within the device. Under these conditions, an additional field-dependent process affecting the spin-dependent recombination emerges, possibly related to the build-up of triplet excitons and their interaction with free charge carriers. Suppression of the EL alone does not prove electronic spin polarization. We therefore probe changes in the spin statistics of recombination directly in a dual singlet-triplet emitting material, which shows a concomitant rise in phosphorescence intensity as fluorescence is suppressed. Finite spin-orbit coupling in these materials gives rise to a microscopic distribution in effective g-factors of electrons and holes, Δg, i.e., a distribution in Larmor frequencies. This Δg effect in the pair, which mixes singlet and triplet, further suppresses singlet-exciton formation at high fields in addition to thermal spin polarization of the individual carriers.

The Effects of Hydrogen Distribution on the Elastic Properties and Hydrogen-Induced Hardening and Softening of α-Fe

In this work, we conducted a high-throughput atomistic simulation of the interstitial solid solutions of hydrogen in α-Fe. The elastic constants and moduli were calculated. Through statistical analysis of structures and results, the influences of the microscopic distribution of hydrogen on the elastic moduli, as well as hydrogen-induced hardening and softening, are discussed. We found that even though the uniformly distributed hydrogen caused slight softening in α-Fe, the distribution of hydrogen at different adjacent positions significantly affected the elastic moduli. For example, hydrogen increased the Young’s modulus and shear modulus at the 5th and 10th nearest neighbors, resulting in hardening, but decreased the bulk modulus at the 7th nearest neighbor, making the material easier to compress. These phenomena are related to the distribution densities of the positions that hydrogen atoms can occupy on the two major slip families, {110} and {112}, at different nearest neighbors distinguished by distances.

Microscopic distribution of nerve fibers and ganglia within the bladder trigone in women – a cadaveric studycadaveric study

Background and aims. The microscopic description of the nerve fibers responsible for micturition is useful when planning minimally invasive interventions for refractory overactive bladder such as intravesical botulinum toxin injections. The purpose of this study was to investigate the density of nerves and ganglia within the bladder trigone, with a focus on identifying areas with a higher density. Methods. Urinary bladders were harvested from 3 female cadavers. Following tissue processing, a total of 100 slides stained with hematoxylin and eosin (HE) and immunostained for S100 and CD56 were analyzed. The density of nerve fibers (NFD) and ganglia (GD) in 3 different bladder trigone compartments was analyzed. Results. The NFD in the central compartment (16.2±3.9) was significantly higher than in both the peripheral (p=0.0005) and the intermediary (p=0.01) compartments. The GD was the highest in the peripheral compartment, but it was not significantly different from the other compartments. Conclusions. This microscopic study showed a pattern of distribution with a dominance of nerve fibers in the central compartment and a rather homogenous distribution of the ganglia within the female bladder trigone.

An initial-boundary value problem for Boltzmann’s non-stationary nonlinear one-dimensional four-moment system of equations

In this article, the set of boundary conditions is defined for first and boundary value problems for the second approximation of Boltzmann’s system of one-dimensional nonlinear moment equations and their logic. For the second approximation of Boltzmann’s one-dimensional non-stationary nonlinear moment equations, which satisfies the Maxwell-Auzhan boundary condition, the theorem for the first boundary problem is considered and by proving this theorem, it is proved that there are only solutions to the given problems. It is known that in many problems of gas dynamics there is no need to describe the complete state of the gas by the function of microscopic distribution of molecules. Therefore, it is better to look for an easier way to describe the gas using macroscopic gas – dynamic variables (density, hydrodynamic average velocity, temperature) are determined in this rotations by the moments of the microscopic distribution function of the molecules, the author faced with the problem of analyzing the different moments of the Boltzmann equation. By studying the moment equations, the author obtained some information about the function of the microscopic distribution of molecules and the convergence of the moment method.