Ice Particles Trapped by Temperature Gradients at mbar Pressure

In laboratory experiments we observe that ice particles (\leq100 \mu m) entrained in a low pressure atmosphere (~1 mbar) get trapped by temperature gradients between three reservoirs at different tempertature. Confining elements are a peltier element at 250 K (bottom), a liquid nitrogen reservoir at 77 K (top) and the surrounding vacuum chamber at 293 K. Particle levitation and trapping is modeled by an interplay of thermophoresis, photophoresis and gravity. A number of ice particles are trapped simultaneously in close spatial distance to each other at least up to minutes and are accessible for further experiments.Comment: Published in Review of Scientific Instruments 82, 2011, 4 pages, 6 figure

Non-Newtonian effects in the peristaltic flow of a Maxwell fluid

We analyzed the effect of viscoelasticity on the dynamics of fluids in porous media by studying the flow of a Maxwell fluid in a circular tube, in which the flow is induced by a wave traveling on the tube wall. The present study investigates novelties brought about into the classic peristaltic mechanism by inclusion of non-Newtonian effects that are important, for example, for hydrocarbons. This problem has numerous applications in various branches of science, including stimulation of fluid flow in porous media under the effect of elastic waves. We have found that in the extreme non-Newtonian regime there is a possibility of a fluid flow in the direction {\it opposite} to the propagation of the wave traveling on the tube wall.Comment: to Appear in Phys. Rev. E., 01 September 2001 issu

Effect of the Deposition Parameters on the Phase-Structure State, Hardness, and Tribological Characteristics of Mo2 N/CrN Vacuum - Arc Multilayer Coatings

A complex study has been performed of the effect of the technological parameters, which are responsible for the energy states of deposited particles, on the elemental, phase and structure compositions, hardness, and tribological characteristics of formed vacuum-arc multilayer Mo2N/CrN systems with a nanometric thickness. The formation of two phase and structure types has been defined in combined nitride layers: γ-Mo2N/CrN with the isostructural cubic crystalline lattices and γ-Mo2N/CrN with nonisostructural cubic and hexagonal lattice

Nanostructured coatings based on amorphous carbon and gold nanoparticles obtained by the pulsed vacuum-arc method

Nanostructured coatings based on diamond-like carbon and gold-doped carbon with a thickness of 100-300 nm were obtained by a pulsed vacuum-arc method on silicon substrates. The structure of the coatingswas studied by high-resolution transmission electron microscopy, the elemental composition was studied by X-ray microanalysi

Features of optical characteristics of atmospheric aerosol in the Middle Urals

The results of studies into the aerosol optical depth (AOD) for the atmosphere in the Middle Urals in the spectrum range of 0.34-1.02 μm for 2004-2010 is presented. The interannual, annual, seasonal, and daily variations in the AOD are analyzed. The major statistical characteristics of the AOD, the parameters of the probability density function of distributions over different wave lengths, and the parameters of Angstrom's formula for the different seasons are calculated. The monitoring stations in the Russian segment of the AERONET network are ranked with respect to the AOD value. A shift from March to May in the spring maximum of the AOD is revealed in comparison with the results of the actinometric observations for the period of 1960-1986. A qualitative assessment is given to the influence of forest and peat fires in the region on the AOD. A classification of the states of aerosol haze in the atmosphere according to the AOD values is proposed. © 2013 Pleiades Publishing, Ltd

The effect of magnetophoresis and Brownian diffusion on the levitation of bodies in a magnetic fluid

New aspects related to the redistribution of magnetic particles concentration in a magnetic fluid caused by magnetophoresis and Brownian diffusion in a nonuniform magnetic field are considered. These aspects deal with the influence of these processes on pressure redistribution and levitation of bodies in a magnetic fluid. It is shown that due to these processes the pressure force acting on bodies changes significantly with time and can be reduced dozens of percent if compared to a homogenous flui

Structure and properties of vacuum arc single-layer and multiperiod two-layer nitride coatings based on Ti(Al): Si layers

The paper provides an analysis of impact of deposition conditions on structural and phase state and thermal stability of vacuum arc coatings based on Ti(Al):Si layer

Single layer and multilayer vacuum-arc coatings based on the nitride tialsiyn: composition, structure, properties

Using high-technological vacuum-arc evaporation in the atmosphere of nitrogen with ion bombardment, single- and multilayer coatings based on TiAlSiYN with high mechanical characteristics were obtained: hardness of the coatings reached 49.5 GPA, resistance to wear, with the value of the critical point LC5 reaching 184.92 N. The mechanisms of structure formation, defining the resulting mechanical characteristics of single- and multi-layer coatings based on TiAlSiYN nitride have been discusse

Tribotechnical properties of (TiZr)N/(TiSi)N multilayer coatings with nanometer thickness

The tribotechnical characteristics of (TiZr)N/(TiSi)N nitride multilayer coatings obtained by the meth-od of vacuum-arc deposition at room temperature were investigate

(TiZr)N/(TiSi)N Maitilayer nanostructured coatings obtained by vacuum arc deposition

The paper investigates the structure and properties of nanoscale multilayer coatings based on (TiZr)N and (TiSi)N produced by vacuum arc technique. Also, it provides an analysis of the impact of partial pressure of nitrogen on structural and phase state of coating