Mean lifetime of diffusing particle in cylindrical cavity with absorbing spots of arbitrary radii on its bases.

This paper deals with the trapping of a particle diffusing in a cylindrical cavity by two circular absorbing spots of arbitrary radii located in the centers of the cavity bases. The focus is on the mean particle lifetime, which is its mean first-passage time to one of the spots. When the spots are small and their radii are well below the cavity radius, this time can be analyzed using the narrow escape (NE) theory, which describes it as a function of the spot radii and the only parameter of the cavity, its volume, independent of the cavity shape and the particle initial position.

Quasiuniversal behavior of shear relaxation times in simple fluids.

We calculate the shear relaxation times in four important simple monatomic model fluids: Lennard-Jones, Yukawa, soft-sphere, and hard-sphere fluids. It is observed that in properly reduced units, the shear relaxation times exhibit quasiuniversal behavior when the density increases from the gaslike low values to the high-density regime near crystallization. They first decrease with density at low densities, reach minima at moderate densities, and then increase toward the freezing point.

Stokes-Einstein Relation in Different Models of Water.

The purpose of this paper is to discuss to which extent a microscopic version of the Stokes-Einstein (SE) relation without the hydrodynamic radius applies to liquid water. We demonstrate that the self-diffusion and shear viscosity data for five popular water models, recently reported by Ando [J. Chem.

Laser-Driven Proton-Only Acceleration in a Multicomponent Near-Critical-Density Plasma.

An experimental investigation of collisionless shock ion acceleration is presented using a multicomponent plasma and a high-intensity picosecond duration laser pulse. Protons are the only accelerated ions when a near-critical-density plasma is driven by a laser with a modest normalized vector potential. The results of particle-in-cell simulations imply that collisionless shock may accelerate protons alone selectively, which can be an important tool for understanding the physics of inaccessible collisionless shocks in space and astrophysical plasma.

Theory of stability of self-sustaining dc discharges at inception with application to negative corona.

The inception of self-sustaining dc discharges is analyzed in terms of the bifurcation theory. The existence of a nonphysical solution with negative ion and electron densities must be taken into account in order to identify the bifurcation type. The bifurcation is transcritical for positive and negative corona discharges and, in more general terms, it is expected to be transcritical for all discharge configurations except for the parallel-plate discharge, where the bifurcation is pitchfork.

Observation of Le Sage gravity analog in complex plasma.

Fragmentation of a suspension of micron-sized plastic microparticles and their contraction into dense globules was experimentally obtained in a gas discharge plasma, when the plasma density was deliberately and abruptly increased. The globules took up spherical shapes 0.14-1.

Entropy of strongly coupled Yukawa fluids.

The entropy of strongly coupled Yukawa fluids is discussed from several perspectives. First, it is demonstrated that a vibrational paradigm of atomic dynamics in dense fluids can be used to obtain a simple and accurate estimate of the entropy without any adjustable parameters. Second, it is explained why a quasiuniversal value of the excess entropy of simple fluids at the freezing point should be expected, and it is demonstrated that a remaining very weak dependence of the freezing point entropy on the screening parameter in the Yukawa fluid can be described by a simple linear function.

First-principles molecular dynamics of exciton-driven initial stage of plasma phase transition in warm dense molecular nitrogen.

Understanding the properties of molecular nitrogen N2 at extreme conditions is the fundamental problem for atomistic theory and the important benchmark for the capabilities of first-principles molecular dynamics (FPMD) methods. In this work, we focus on the connection between the dynamics of ions and electronic excitations in warm dense N2. The restricted open-shell Kohn-Sham method gives us the possibility to reach relevant time and length scales for FPMD modeling of an isolated exciton dynamics in warm dense N2.

Reply to "Comment on 'Ultracold plasma expansion in quadrupole magnetic field' ".

In this Reply, we respond to the Comment by Schlitters et al. on our recent work [Phys. Rev.

Inverse Phase Transition in Droplet Clusters Levitating over the Locally Heated Water Layer.

Self-assembled microdroplet clusters can levitate above a locally heated water surface. Normally, the temperature of droplets is in the range of 50-95 °C. However, it is possible to generate clusters at lower temperatures.

New analysis of the temperature-dependent threshold density for electron self-trapping in gaseous helium.

We present the results of a new analysis of the literature data on electron mobility μ in dense helium gas aimed at determining the existence of a threshold density for electron self-trapping in gaseous helium as a function of temperature. We have investigated the density dependence of μ and, when available, its dependence on the electric field. The experimental data are favorably rationalized by minimizing the excess free energy of the self-localized states within the optimum fluctuation model.

Vacancy formation in a 1D chain of dust particles in a DC discharge.

The paper presents the first experimental observation of an atypical phenomena during self-organization of dust particles into a one-dimensional chain structure levitated vertically in the plasma of a DC glow discharge. Using a laser, the third (middle) dust particle was removed from the chain of five particles so that the positions of the remaining particles did not significantly change, and a vacancy occurred in the place of the removed particle. This state of the chain turned out to be very stable, which is confirmed by the observation of the subsequent exchange of places of the fourth and the fifth particles of the chain upon the action of the laser on the forth particle.

Electric field-induced clustering in nanocomposite films of highly polarizable inclusions.

A nanocomposite film containing highly polarizable inclusions in a fluid background is explored when an external electric field is applied perpendicular to the planar film. For small electric fields, the induced dipole moments of the inclusions are all polarized in field direction, resulting in a mutual repulsion between the inclusions. Here we show that this becomes qualitatively different for high fields: the total system self-organizes into a state which contains both polarizations, parallel and antiparallel to the external field such that a fraction of the inclusions is counter-polarized to the electric field direction.

Inversion of Stabilized Large Droplet Clusters.

We investigate the spontaneous rearrangement of microdroplets in a self-assembled droplet cluster levitating over a thin locally heated water layer. The center-to-periphery droplet diameter ratio (the "inversion coefficient") controls the onset of the inversion. Larger droplets can squeeze between smaller ones due to increased drag force on them from the air-vapor flow.

Atomic Force Microscopy Study of the Long-Term Effect of the Glycerol Flow, Stopped in a Coiled Heat Exchanger, on Horseradish Peroxidase.

Glycerol is employed as a functional component of heat-transfer fluids, which are of use in both bioreactors and various biosensor devices. At the same time, flowing glycerol was reported to cause considerable triboelectric effects. Herein, by using atomic force microscopy (AFM), we have revealed the long-term effect of glycerol flow, stopped in a ground-shielded coiled heat exchanger, on horseradish peroxidase (HRP) adsorption on mica.

Shoving model and the glass transition in one-component plasma.

A modified shoving model is applied to estimate the location of the glass transition in a one-component plasma. The estimated value of the coupling parameter Γ ≃ 570 at the glass transition is compared with other predictions available in the literature.

Universal scaling of transverse sound speed and its isomorphic property in Yukawa fluids.

Molecular dynamical simulations are performed to investigate the scaling of the transverse sound speed in two-dimensional (2D) and 3D Yukawa fluids. From the calculated diagnostics of the radial distribution function, the mean-squared displacement, and the Pearson correlation coefficient, the approximate isomorphic curves for 2D and 3D liquidlike Yukawa systems are obtained. It is found that the structure and dynamics of 2D and 3D liquidlike Yukawa systems exhibit the isomorphic property under the conditions of the same relative coupling parameter Γ/Γ_{m}=const.

Steady-State Ultracold Plasma Created by Continuous Photoionization of Laser Cooled Atoms.

In this Letter we discuss our approach that makes possible creation of the steady-state ultracold plasma having various densities and temperatures by means of continuous two-step optical excitation of calcium atoms in the magneto-optical trap. A strongly coupled ultracold plasma can be used as an excellent test platform for studying many-body interactions associated with various plasma phenomena. The parameters of the plasma are studied using laser-induced fluorescence of calcium ions.

Freezing density scaling of transport coefficients in the Weeks-Chandler-Andersen fluid.

It is shown that the transport coefficients (self-diffusion, shear viscosity, and thermal conductivity) of the Weeks-Chandler-Andersen (WCA) fluid along isotherms exhibit a freezing density scaling (FDS). The functional form of this FDS is essentially the same or closely related to those in the Lennard-Jones fluid, hard-sphere fluid, and some liquefied noble gases. This proves that this FDS represents a quasi-universal corresponding state principle for simple classical fluids with steep interactions.

Phase-space path-integral representation of the quantum density of states: Monte Carlo simulation of strongly correlated soft-sphere fermions.

The Wigner formulation of quantum mechanics is used to derive a path-integral representation of the quantum density of states (DOS) of strongly correlated fermions in the canonical ensemble. A path-integral Monte Carlo approach for the simulation of DOS and other thermodynamic functions is suggested. The derived Wigner function in the phase space resembles the Maxwell-Boltzmann distribution but allows for quantum effects.

Exogenous GABA supplementation to facilitate Cr (III) tolerance and lipid biosynthesis in Chlorella sorokiniana.

Microalgae possess the prospective to be efficiently involved in bioremediation and biodiesel generation. However, conditions of stress often restrict their growth and diminish different metabolic processes. The current study evaluates the potential of GABA to improve the growth of the microalga Chlorella sorokiniana under Cr (III) stress through the exogenous administration of GABA.

Engineering of graphene-based composites with hexagonal boron nitride and PEDOT:PSS for sensing applications.

A unique nanomaterial has been developed for sweat analysis, including glucose level monitoring. Simple resusable low-cost sensors from composite materials based on graphene, hexagonal boron nitride, and conductive PEDOT:PSS (poly(3,4-ethylenedioxythiophene)polystyrene sulfonate) polymer have been developed and fabricated 2D printing on flexible substrates. The sensors were tested as biosensors using different water-based solutions.

Graphene-based multifunctional humidity sensors with an ultrahigh current response.

Prospective composites, based on graphene (G) and hexagonal boron nitride (h-BN) nanoparticles, synthesized using a plasma jet and conducting polymer PEDOT:PSS, were used to create and study a set of sensors in the current study. The composites used were G:PEDOT:PSS (GPP) and G:h-BN:PEDOT:PSS (GBNPP). The PEDOT:PSS content in the composites was 10 wt%, and the ratio of G : h-BN was 1 : 1 in GBNPP.