Leaching of Impurities from Poor Intermediate Products of Refining Production in Autoclave Conditions

Russian Journal of Applied Chemistry - At elevated temperatures (130 and 180°C) in hydrothermal autoclave conditions, the possibility of deep extraction of noble metals from poor intermediate...     

Effects of Dry-Jet Wet Spinning Parameters on Properties of Polysulfone Hollow Fiber Membranes

Russian Journal of Applied Chemistry - The influence of parameters of the dry-jet wet spinning process was studied on properties of porous polysulfone hollow fiber membranes. The air gap distance,...     

Polyelectrolyte brushes

The simple scaling theory of weakly-charged polyelectrolyte brush (the layer of polyelectrolyte chains grafted at one end onto an impermeable surface) immersed into a good solvent has been developed.The asymptotic scaling dependences of the free layer thickness on charge density and solvent strength are obtained. The behavior of polyelectrolyte brush subjected to normal and tangential external forces is considered. New “polyelectrolyte effect” is predicted: shear of a free polyelectrolyte brush leads to a decrease in brush thickness in contrast to the case of a free neutral brush. Such behavior is equivalent to that of a neutral brush subjected to external normal stretching force. This force in the case of polyelectrolyte brush is created by the osmotic pressure of mobile counterions neutralizing grafted chain charges.     

The Motion of a Nonholonomic Chaplygin Sphere in a Magnetic Field,the Grioli Problem,and the Barnett–London Effect

Doklady Physics - In this paper, we consider the motion of a nonholonomic Chaplygin sphere on a plane in a constant magnetic field under the assumption that the sphere has dielectric and...     

Translational Motion of Water Molecules near the Interface between Gas and Condensed Matter Using the Self-Similarity Effect and 4D Space

Bulletin of the Lebedev Physics Institute - Abstract—The self-similarity effect during rarefied water vapor flow between two finite-volume vessels is repeatedly recorded with a similarity...     

Convective burning and detonability of aluminum-rich ammonium perchlorate-aluminum-nitromethane mixtures: 1. Experiment

The initiation and propagation of low-velocity detonation in ammonium perchlorate (AP)-aluminum-nitromethane (NM) mixtures with Al: AP ratios of 1: 1 to 2.5: 1 and porosities from 40 (10 wt % HM) to 0% (40 wt % NM) in strong steel shells (in the air) and plastic shells submerged in water are experimentally studied. The optimum contents of the components that provide reliable initiation of steady detonation (at velocities from 2 to 5 km/s) by weak explosive sources in mixtures with an Al: AP ratio of 1: 1 and above are determined. The selected mixtures reproducibly detonate in plastic shells surrounded by a 30-cm-thick layer of water at velocities somewhat lower than in strong steel shells in the air.     

Temperature dependences of the ion-electron emission of glassy carbons under 30-keV argon ion irradiation

The temperature dependences (?200°C < T ≤ 350°C) of the ion-induced electron emission yield γ and the structures of modified surface layers have been studied experimentally for SU-850, SU-1000, SU-1300, SU-2000, and SU-2500 glassy carbons under high-dose 30-keV Ar⁺ and N ₂ ⁺ ion irradiation. Glassy carbons manufactured using a relatively high heat-treatment temperature T _ht exhibit a stepwise increase in the electron yield at certain annealing temperatures T _a. The same behavior is observed for graphitized carbon materials. For low-temperature glassy carbons, the electron yield exhibits a monotonic increase with increasing irradiation temperature. The observed differences are related to the occurrence of different structural types of fullerene-like nanoparticles in the low-and high-temperature glassy carbons.     

New Types of Solutions for the Classic 3D SU (2) Yang–Mills Equations

Doklady Physics - New types of 3D solutions for the classic Yang–Mills equations in the Faddeev–Niemi reformulation are found. In a particular case, these solutions describe 3D vortices.     

Asymptotic Behavior of the Mean Sojourn Time for a Random Walk to be in a Domain of Large Deviations

Siberian Advances in Mathematics - We study the asymptotic behavior of the mean of sojourn time for a homogeneous random walk defined on $$ [0,n]$$ to be above a receding curvilinear boundary in a...     

Crystallographic Analysis of the Structure of LaBiI<Subscript>6</Subscript>·13H<Subscript>2</Subscript>O and NdBiI<Subscript>6</Subscript>·13H<Subscript>2</Subscript>O. Sublattice of Iodine Atoms: A Common Skeleton of the Structures

The crystallographic analysis of the recently determined structures of LaBiI₆·13H₂O and NdBiI₆·13H₂O reveals that their common basis is a sublattice of iodine anions built of coherently assembled octahedral I₆ fragments. The relationship between the parameters of orthorhombic and monoclinic unit cells of these structures is shown and their symmetry features are discussed.