Nonlocal transport in the charge density waves of oo-TaS3_3

We studied the nonlocal transport of a quasi-one dimensional conductor $o$-TaS$_3$. Electric transport phenomena in charge density waves include the thermally-excited quasiparticles, and collective motion of charge density waves (CDW). In spite of its long-range correlation, the collective motion of a CDW does not extend far beyond the electrodes, where phase slippage breaks the correlation. We found that nonlocal voltages appeared in the CDW of $o$-TaS$_3$, both below and above the threshold field for CDW sliding. The temperature dependence of the nonlocal voltage suggests that the observed nonlocal voltage originates from the CDW even below the threshold field. Moreover, our observation of nonlocal voltages in both the pinned and sliding states reveals the existence of a carrier with long-range correlation, in addition to sliding CDWs and thermally-excited quasiparticles.Comment: 8 pages, 4 figure

Polyhedral Topological Crystals

We have synthesized micrometer-scale polyhedral ring crystals of TaS3 by the chemical vapor transportation method. The polyhedral ring crystals are closed-loop crystals with several vertices. We investigated the crystallinity and flatness of the facets by the electron backscatter diffraction technique and found that the orientation of the crystal axis changed abruptly at several points. Observing the size of the crystals, we found a new phase of topological crystals and propose a phase diagram of ring-polyhedral crystals in terms of radius and thickness. We also propose a mechanism of polygonization in which the vertices of the polyhedral crystals are formed from concentrated dislocations as a result of distancedependent interactions between them

Influence of Solution Temperature and Surfactants on Morphologies of Tin Oxide Produced Using a Solution Plasma Technique

Single-crystalline tin oxide (SnO) plates were synthesized by a solution plasma technique using an Sn wire. In the experiments, we applied a voltage of 400 V in a 0.001 M K2CO3 solution. The effects on the products of the solution temperature, the use of surfactants, and the cooling rate were investigated. A solution temperature above 95.0 °C was effective for producing single-crystal SnO plates. The addition of poly(vinyl alcohol) (PVA) significantly stabilized the Sn6O4(OH)4 octahedrons. In the case of cetyltrimethylammonium bromide (CTAB) addition, SnO and Sn crystals with plate crystal, particle, and rod morphologies were formed. Quenching the solution affected the product size. Faster cooling rates reduced the size of the SnO plates. SnO plates with (001) plane faces precipitated from Sn(OH)3 − ions to form plate-like crystals as a result of the difference in the growth rates at each plane

Improvement on Heat Release Performance of Direct-contact Heat Exchanger Using Phase Change Material for Recovery of Low Temperature Exhaust Heat

Latent heat storage using a phase change material (PCM) is a promising method for utilizing the exhaust heat from steelworks. The purpose of this study was to improve the heat release performance of a direct-contact heat exchanger using a PCM and heat transfer oil (HTO). Erythritol (with a melting point of 391 K), which is a kind of sugar alcohol, was selected as a PCM. A vertical stainless steel cylinder with an inner diameter of 200 mm and height of 1400 mm was used as the heat storage unit (HSU). A ring-shaped injector with 18 holes positioned vertically downward was placed at the bottom of the HSU. Each hole in this injector had a diameter of 2.5 mm. We investigated the effects of the height of the PCM in the HSU, the HTO flow rate, and an increase in the number of injection-nozzle holes on the temperature effectiveness and heat exchange rate as indices of the heat release performances. As results, we found that an increase in the number of nozzle holes accelerated the uniform distribution of the HTO in the liquid PCM, prevented the HTO drift flow and adverse solidification of the PCM, and improved the heat release performance under the condition of a high HTO flow rate

Surface morphology of a glow discharge electrode in a solution

This paper describes the surface morphology of a glow discharge electrode in a solution. In the experiments detailed in the paper, the effects of electrolysis time, solution temperature, voltage, electrolyte concentration, and surface area on the size of nanoparticles formed and their amount of nanoparticles produced were examined to study the surface morphologies of the electrodes. The results demonstrated that the amount of nanoparticles produced increased proportionally with the electrolysis time and current. When the voltages were below 140 V, surfaces with nanoparticles attached, called “Particles” type surfaces, were formed on the electrode. These surfaces changed and displayed ripples, turning into “Ripple” type surfaces, and the nanoparticle sizes increased with an increase in the amount of nanoparticles produced. In contrast, at voltages over 160 V, the surfaces of the electrodes were either “Random” or “Hole” type and the particle sizes were constant at different amount of nanoparticles produced

Ripple formation on a nickel electrode during a glow discharge in a solution

We investigated ripple formation on a nickel electrode during a glow discharge in a solution. A nickel wire was partially melted to produce nanoparticles during glow discharge electrolysis. When the electrolysis time was over 30 min, a ripple pattern was formed on the electrode surface, and particle size increased. In this study, we investigated the relationship between the ripple formation and crystal orientation of the electrode. As a result, the ripple patterns were formed on all planes, except (111)- and (100)-oriented planes; their direction was [001]