Radiation Effects in Tungsten and Tungsten-Copper Alloys Treated with Compression Plasma Flows and Irradiated with He Ions.

The paper presents the results of studying the structure and phase state of tungsten and tungsten-copper alloy after pulsed action of compression plasma flows and irradiation with helium ions. The compression plasma flows were used to modify the surface layer of tungsten, as well as to create an alloy based on tungsten and copper. Using scanning electron microscopy and X-ray structural analysis, the formation of radiation defects on the tungsten surface was detected in the form of local areas of exfoliation and destruction, which begin to form at helium ion irradiation doses of 2 × 10 cm.

Effect of hydrophobized PET TeMs membrane pore-size on saline water treatment by direct contact membrane distillation.

This paper describes the desalination process by membrane distillation (MD) using track-etched membranes (TeMs). Hydrophobic track-etched membranes based on poly(ethylene terephthalate) (PET TeMs) with pore diameters from 700 to 1300 nm were prepared by UV-initiated graft polymerization of lauryl methacrylate (LMA) inside the nanochannels. Modified PET TeMs were investigated by Fourier transform infrared (FTIR) spectroscopy, atomic force microscopy (AFM), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and contact wetting angle (CA) measurements.

The Influence of Nitrogen Flow on the Stoichiometric Composition, Structure, Mechanical, and Microtribological Properties of TiN Coatings.

Utilizing reactive DC magnetron sputtering method, TiN coatings were deposited on the silicon substrates at different nitrogen flows and powers. A study of the X-ray phase composition of the coatings was carried out. The stoichiometric composition of the coatings was determined using energy dispersive x-ray spectroscopy.

Ruthenium and Platinum-Modified Titanium Dioxide Support for NaBH Hydrolysis.

Highly stable platinum (Pt) and ruthenium (Ru)-based catalysts on titanium oxide (TiO) nanoparticle support were prepared. The productivity of hydrogen generation from sodium borohydride (NaBH) hydrolysis was observed to be as high as 95%. The activation energies for the hydrolysis reaction in the presence of Ru/TiO in aqueous and alkaline solutions were 62.

Atomic insights into thickness-dependent deformation mechanism and mechanical properties of Ag/PMMA ultra-thin nanofilms.

In this work, the nanoindentations on bilayer composite nanofilms composed of metal Ag and polymer PMMA were simulated using molecular dynamics. The effects of the thickness of Ag and PMMA on the elastic moduli of the composite films were analyzed from Hertz contact theory, dislocation evolution and atomic migration. The results show that the maximum penetration depth that the Hertz model could well describe is about 6 Å, and this limiting value is almost independent on the film thickness.

Structure and Phase Composition of WNb Alloy Formed by the Impact of Compression Plasma Flows.

The results of a tungsten-niobium alloy synthesis by the impact of pulsed compression plasma flows are presented. Tungsten plates with a 2 μm thin niobium coating were treated with dense compression plasma flows generated by a quasi-stationary plasma accelerator. The plasma flow with an absorbed energy density of 35-70 J/cm and pulse duration of 100 μs melted the niobium coating and a part of the tungsten substrate, which caused liquid-phase mixing and WNb alloy synthesis.

Stimuli-Responsive Track-Etched Membranes for Separation of Water-Oil Emulsions.

In this work, we have developed a method for the preparation of pH-responsive track-etched membranes (TeMs) based on poly(ethylene terephthalate) (PET) with pore diameters of 2.0 ± 0.1 μm of cylindrical shape by RAFT block copolymerization of styrene (ST) and 4-vinylpyridine (4-VP) to be used in the separation of water-oil emulsions.

Graft Polymerization of Stearyl Methacrylate on PET Track-Etched Membranes for Oil-Water Separation.

In this article, results of PET track-etched membranes (PET TeMs) hydrophobized by photo-induced graft polymerization of stearyl methacrylate (SM) inside the pores were presented. The effects of monomer concentration, time of irradiation and the nature of the solvent on the degree of grafting and membrane morphology were investigated. The PET TeMs with pore diameters ranging from 350 nm (pore density of 1 × 10 pore/cm) to 3.

Modification of Thin Film Composite PVA/PAN Membranes for Pervaporation Using Aluminosilicate Nanoparticles.

The effect of the modification of the polyvinyl alcohol (PVA) selective layer of thin film composite (TFC) membranes by aluminosilicate (AlO·SiO) nanoparticles on the structure and pervaporation performance was studied. For the first time, PVA-AlO·SiO/polyacrylonitrile (PAN) thin film nanocomposite (TFN) membranes for pervaporation separation of ethanol/water mixture were developed via the formation of the selective layer in dynamic mode. Selective layers of PVA/PAN and PVA-AlO·SiO/PAN membranes were formed via filtration of PVA aqueous solutions or PVA-AlO·SiO aqueous dispersions through the ultrafiltration PAN membrane for 10 min at 0.

Light-Induced Color Switching of Single Metal-Organic Framework Nanocrystals.

Photoinduced modulation of the optical parameters of nanomaterials underlies the operating principles of all-optical nanodevices. Here, we demonstrate the laser-induced 10% modulation of the refractive index and 16-fold modulation of the extinction coefficient of the dynamic metal-organic framework (HKUST-1) nanocrystals within the whole visible range. Using the laser-induced water sorption/desorption process inside HKUST-1, we have achieved size-dependent reversible tuning of brightness and color of its nanocrystals over the different spatial directions and color palette.

Preparation of Hydrophobic PET Track-Etched Membranes for Separation of Oil-Water Emulsion.

The paper describes the separation of an oil-water emulsion by filtration using poly(ethylene terephthalate) track-etched membranes (PET TeMs) with regular pore geometry and narrow pore size distribution. PET TeMs were modified with trichloro(octyl)silane to increase their hydrophobic properties. Conditions for the modification of PET TeMs with trichloro(octyl)silane were investigated.

Structure and Properties of ZrON Coatings Synthesized by Cathodic Arc Evaporation.

The transition metal oxynitrides are a coating material with decorative features due to their adjustable color and good mechanical properties. The purpose of the research was to study the effect of the relative oxygen concentration O = O/(N + O) in particular on adhesion, but also on the color, structural and mechanical properties of ZrON coatings synthesized by cathodic arc evaporation on HS6-5-2 steel substrates. The surface morphology, phase and chemical composition and mechanical properties were determined using scanning electron microscopy, X-ray diffraction, wavelength dispersive X-ray spectroscopy, nanoindentation and scratch test.

Effect of Metallic or Non-Metallic Element Addition on Surface Topography and Mechanical Properties of CrN Coatings.

Alteration of the phase composition of a coating and/or its surface topography can be achieved by changing the deposition technology and/or introducing additional elements into the coating. Investigation of the effect of the composition of CrN-based coatings (including AlCrN and CrON) on the microparticle height and volume, as well as the construction of correlations between the friction coefficient at the microscale and the geometry of microparticles, are the goals of this study. We use atomic force microscopy (AFM), which is the most effective method of investigation with nanometer resolution.

Graphene@Metal Nanocomposites by Solution Combustion Synthesis.

Graphene (G) and metal-decorated G nanocomposites are among the most promising materials for a wide variety of practical applications, and, therefore, the development of fast and reliable methods for nanocomposite synthesis is an important task. Herein we report the new fast approach for solution combustion synthesis (SCS) of large-area G-metallic nanocomposites in an air atmosphere. The G-based nanocomposites were obtained by a SCS using copper and nickel nitrates, as well as their stoichiometric mixture as the metal source and citric acid as a fuel and carbon source.

The effect of myeloperoxidase isoforms on biophysical properties of red blood cells.

Myeloperoxidase (MPO), an oxidant-producing enzyme, stored in azurophilic granules of neutrophils has been recently shown to influence red blood cell (RBC) deformability leading to abnormalities in blood microcirculation. Native MPO is a homodimer, consisting of two identical protomers (monomeric MPO) connected by a single disulfide bond but in inflammatory foci as a result of disulfide cleavage monomeric MPO (hemi-MPO) can also be produced. This study investigated if two MPO isoforms have distinct effects on biophysical properties of RBCs.

Processing of biomedical waste in plasma gasifier.

The problem of treatment of household and biomedical waste containing toxic substances is becoming increasingly important. In contrast to the conventional incineration, plasma gasification of the waste provides reliable destruction of highly toxic dioxins, benzo(a)pyrene and furans. This article presents the results of thermodynamic analysis and experiments on gasification of the waste of various origins in the plasma reactor.

Hydrodynamic instability in a magnetically driven suspension of paramagnetic red blood cells.

We investigate the magnetically driven motion in suspensions of paramagnetic particles. Our object is diluted deoxygenated whole blood with paramagnetic red blood cells (RBCs). We use direct observations in a closed vertical Hele-Shaw channel, and a well-defined magnetic force field applied horizontally in the channel plane.

Analytical model of batch magnetophoretic separation.

Magnetophoresis (the motion of magnetic particles driven by the nonuniform magnetic field), that for a long time has been used for extracting magnetically susceptible objects in diverse industries, now attracts interest to develop more sophisticated microfluidic and batch techniques for separation and manipulation of biological particles, and magnetically assisted absorption and catalysis in organic chemistry, biochemistry, and petrochemistry. A deficiency of magnetic separation science is the lack of simple analytical models imitating real processes of magnetic separation. We have studied the motion of superparamagnetic (generally, soft magnetic) particles in liquid in the three-dimensional field of the diametrically polarized permanent cylindrical magnet; this geometry is basically representative of the batch separation mode.

Magnetophoretic trajectory tracking magnetometry: a new technique for assessing magnetic properties of submagnetic microparticles and cells.

We develop a new approach for assessing magnetic properties of submagnetic microparticles and cells, magnetophoretic trajectory tracking magnetometry (MTTM), that employs recording of long 2D trajectories of particle motion in a slot fluid channel caused by the action of crossed gravitational and magnetic forces. The studies are focused on the development of theoretical backgrounds of the method and evaluation of its uncertainty caused by the mutual hydrodynamic entrainment of moving particles. Computerized equipment implementing MTTM technique is described and its performance is illustrated.

Cluster size distribution in percolation theory and fractal Cantor dust.

Results of numerical simulation of cluster size distribution in the site percolation problem are presented. These results disagree with the theoretical data obtained on the basis of the standard drop model of finite cluster structure, in particular, they give a different value of exponent zeta (lnn{s} approximately -s{zeta}). Therefore, a more precise fractal model for describing the structure of clusters in a percolation system is proposed.

Method of laser activated nano-thermolysis for elimination of tumor cells.

We describe novel ex vivo method for elimination of tumor cells from cell suspension, Laser Activated Nanothermolysis and propose this method for purging of bone marrow and blood transplants. K562 and human lympholeukemia cells were eliminated in experiments by laser-induced micro-bubbles that emerge inside individual target cells around selectively formed clusters of light-absorbing gold nanoparticles. Pretreatment of tumor cells with specific monoclonal antibodies and Ig-conjugated 30-nm gold particles allowed the formation of clusters of 10-20 on the surface of cell membrane.

Effect of random internal structure on combustion of binary powder mixtures.

Combustion of a mixture of two solid reactants is considered. A combined geometrical and physicochemical model of mixing of these reactants is proposed. The model takes into account random distribution of reactants and voids over the system.

Surfaces of percolation systems in lattice problems.

The internal and external surface area of a percolation cluster along with a full surface area of whole percolation system are investigated both analytically and numerically. Numerical simulation is performed by a Monte Carlo method for site and bond problems on square and simple cubic lattices. It is shown that both the external and full surface areas of a percolation cluster as well as the full surface area of the whole percolation system have maxima for a certain share of occupied sites (for the site problem) or permeable bonds (for a bond problem).

Large clusters in supercritical percolation.

The statistical behavior of the size of large finite clusters in supercritical percolation on a finite lattice is investigated (below the critical dimension of the space d(c)=6). For this purpose, an approximate system of ordinary differential equations for a number of finite clusters is obtained. The correlation between the critical exponents zeta that determine the cluster decay law (ln n(s) approximately -s(zeta)) and the surface of clusters is shown.