Solid State Phenomena Vol. 323

Abstract: Slurry pumps are used to move and lift a mixture of copper ore and water at mineral processing plants. However, in the process, the pumps wear out at a high rate, which is costly and time consuming. This paper is a characterization of the chemical composition, microstructure, and hardness of samples from a copper ore mining company’s slurry pump and gravel material. With this information, studies using new technology and cladding materials can then be conducted, to compare and select the most effective treatment of the slurry pump’s surfaces to increase its operational lifetime.

Abstract: Using L-octanoyl alanine and L-octanoyl phenylalanine as precursors, they are reacted with magnesium hydroxide to prepare two low-molecular complexes Mg(oct-L-ala)₂ and Mg(oct-L-phe)₂. The composition and structure of the two complexes are characterized by elemental analysis, nuclear magnetic resonance spectroscopy and moisture analyzer, with the solubility and aggregation behavior of the complexes studied. A comparison of the two complexes shows that the Mg(oct-L-ala)₂ complex exhibits better solubility and is easier to aggregate in the mixed solution. In addition, the aggregated solid formed by the aggregation of these two complexes in the solution has optically heterogeneous properties. After further heating and cooling treatment, the Mg(oct-L-phe)₂ complex still retains the optically anisotropic state (liquid crystal state), while the Mg(oct-L-ala)₂ complex forms an optically homogeneous morphology (glass state). This may be affected by the benzene ring functional group in the Mg(oct-L-phe)₂ complex.

Abstract: We applied the dielectric function method to solve analytically L-NL-L structure problems with negative Kerr nonlinearity. A damped wave in linear and a periodic standing wave in non-linear media had to be matched at boundaries. We gave a formulation of boundary conditions that did not explicitly include a film thickness. The boundary-value of a dielectric function can be expressed through the constant of non-trivial integral of motion. Using it, one generates a family of matched solutions satisfying boundary conditions. Then arbitrary film thickness can be checked against this family of solutions in search of matches. As a result, all fitted solutions are determined straightforwardly.

Abstract: Products from an arc discharge between various conducting materials (copper-copper, graphite-graphite, natural graphite and their combination) in water and air have been studied. The SEM and SEM-EDS analysis, and the BET analysis on products from discharges were done as well identifying their size distribution. There are two essential types of product taken in investigation as (i) pure metallic particulates, and (ii) specific structures of materials. The visual properties of nano-sized products formed in two media at different current are compared. In products obtained in air, tiny spherical particulates of size in nano-order are observed repeatedly, as well ordinary nano-sized particulates as ones in water. The main visual feature of the particulates formed in air is their existence in deposition in which they are separated by itself. Plenty of individual scrolling sheets of graphite layer of enormous size frequently encounter in soot on electrodes.

Abstract: In this study, we report a change of morphological distribution for PM2.5 air pollution in Ulaanbaatar. Comparing the measurement results in 2011 and 2017 the concentration of particle size 0.8μm was decreased from 92% to 76.7%. Among winter samples in 2011 it is identified 0.4-0.8μm sized particles covering 48.8% of total, and for samples in 2017 it is 61.7%. This shows that 0.4-0.8 microns of particulate matter predominate in the air pollution caused by solid fuel combustion. The 66.8% of the particles identified <0.8μm sized are in summer samples in 2011. This percentage has increased up to 94.5% in the samples in 2017. It is having been to the most harmful fraction of particulate matters for human health. About particulate shapes distribution, irregular shapes dominated in winter in 2011 and sphere shapes dominated in summer samples. While irregular shapes dominated in the samples in 2017, it was independent of season. This provides on origin of pollution, for example, the summer PM_2.5 pollution is sphere shape from the soil in summer and winter PM_2.5 pollution is irregular from the solid fuel combustion. This is a pilot compared study of PM_2.5 particles in air pollution of Ulaanbaatar.

Abstract: Pairwise effective potentials in first seventeen shells of the Ni-22.5at.%Fe alloy are calculated using model potential method with account of the linear size effect. Using obtained values of pairwise effective potentials, the short range order parameters on the first seventeen shells of alloy are calculated by Krivoglaz-Clapp-Moss method. The calculated values ​​of the short-range order parameters were fitted to the experimental values ​​by varying the parameters of static atomic displacements. Reliable value of critical temperature of order-disorder phase transition in Ni-22.5at.%Fe alloy was calculated using obtained meanings of pairwise effective potentials.

Abstract: The numerous 1-D and 2-D nanomaterials: nanotubes, nanowires (NWs), graphene, etc. were discovered, synthesized and intensively studied in the past decades. These nanomaterials had appeared to reveal the unique physical and functional properties allowing constructing the large number of nanodevice based on single nanoobjects. Recently many studies have led to a wide range of proof-of-concept of individual nanoscale devices including nanolasers, nanosensors, field-effect transistors (nanoFETs) and many others based on NWs, carbon nanotubes (CNT) and many other nanoobjects. Such nanodevices represent attractive building blocks for hierarchical assembly of microscale and macroscopic devices which are attractive for creating of micro-and –macro-devices and arrays by the bottom-up and hybrid paradigm. In this paper the conceptual survey is given of nowadays achievements in the field of mechanical bottom-up nanoassembling. We emphasize on the system based on smallest and the fastest in the World nanotweezer developed on the base of the new smart materials with shape memory effect for nanomanipulation of real nanoobjects. We discuss the recent experiments on nanomanipulation, nanoassembling and nanomanufacturing of nanoand micro-devices using this method, which in many cases can replaced very expensive “top-down” technologies.

Abstract: The surface structure of the WSe₂ were studied using scanning tunneling microscopy. Exfoliation method in an ultra-high-vacuum chamber method is used to obtain a clean surface of WSe₂ samples with atomically smooth terraces and multi-layer steps. Atomic-resolution images revealed two types of atomic defects of surface or near surface. These defects have been identified as the defects in the tungsten atom layer just below the topmost selenium layer.

Abstract: Magnetic nanoparticles for thermotherapy must be biocompatible and possess high thermal efficiency as heating elements. The biocompatibility of Mg_0.8Ni_0.2Fe₂O₄ nanoparticles was studied using a cytotoxicity colony formation assay and a cell viability assay. HeLa cells exhibited cytotoxic effects when exposed to three different concentrations of 150 μg/ml, 100 μg/ml, and 50 μg/ml nanoparticles. Therefore, concentrations of 50 μg/ml showed the lowest cytotoxic activity and the lowest toxicity to living cells. In vitro cytotoxicity of samples was then investigated by two methods, colony formation assay and cell viability assay. The Hela inhibited cell growth as 16.8% during heating by magnetic field generators.

Abstract: We reported the structural, magnetic and magenetocaloric properties of Mn_1.25Fe_0.75P_{0. 50}Si_0.50B_x (x = 0.01, 0.02 and 0.04) X-ray diffraction patterns show that all compounds crystallize in the hexagonal Fe₂P-type crystal structure. Lattice parameter a increases while c decreases with increasing B contents. The Curie temperature of the compounds have been determined, the values are 219, 268 and 323.2 K for x = 0.01, 0.02, 0.04, respectively. The maximum magnetic entropy changes in a field change of 0~1.5 T are 6.1, 5.3 and 3.5J/kg·K for x = 0.01, 0.02 and 0.04, respectively.