Satoshi Uehara

Discharge and flow characteristics using magnetic fluid spikes for air pollution control

This paper presents an investigation of the atmospheric discharge and flow characteristics using a magnetic fluid (MF) for an air cleaning device. High-voltage ac is applied between MF spikes formed under a magnetic field and a flat-plate electrode. These MF-spikes are stretched upward to the opposing electrode sharpening its tip until discharge is generated. Furthermore, MF droplets are ejected from the tips of the spikes (a phenomenon known as electrospray) depending on the MF properties and operating conditions. The atmospheric discharge characteristics were investigated by measuring the discharge current. The cleaning ability of the system was evaluated by measuring the produced ozone concentrations.

Resultative constructions with “implied-result” and “entailed-result” verbs in Thai and English: a contrastive study

Abstract This study aims to make a contrastive investigation of the Thai and English transitive-based resultative constructions which consist of a causative predicate indicated by a transitive verb and a resultative predicate linguistically realized as a verb in Thai and an adjective in English. The resultative constructions which are the object of study in this article are those in which the causative predicate is manifested by two kinds of transitive verbs postulated in this article, namely, “implied-result verbs” and “entailed-result verbs”. This article examines one of the syntactic-semantic behavioral properties of both types of verb in both languages when they co-occur with resultative predicates. It is found in this article that English implied-result and entailed-result verbs are much more restricted in taking resultative predicates than the Thai counterparts. In other words, Thai resultative constructions are more productive than English ones. The productivity in the case of the former is attributed to the aspectual profile shift operating in serial verb constructions in Thai. Thai resultative constructions are arguably an instantiation of serial verb constructions. Resultative constructions in Thai allow both conventionalized as well as unconventionalized scenes to be expressed. In contrast, only conventionalized scenes can be expressed by resultative constructions in English.

Numerical Modelling and Simulation of Chemical Reactions in a Nano-Pulse Discharged Bubble for Water Treatment

A zero-dimensional model to simulate a nano-pulse-discharged bubble in water was developed. The model consists of gas and liquid phases corresponding to the inside and outside of the bubble, respectively. The diffusions of chemical species from the gas to the liquid phase through the bubble interface was also investigated. The initial gas is Ar, but includes a little H2O and O2 in the bubble. The time evolution of the OH concentration in the liquid phase was mainly investigated as an important species for water treatment. It was shown that OH was generated in the bubble and then diffused into the liquid. With the application of a continuous nano-pulse discharge, more OH radicals were generated as the frequency increased at a low voltage for a given power consumption.

Effects of Constituent Orders on Functional Extension Patterns of the Verbs for Give: A Contrastive Study of Thai and Mandarin Chinese

It is generally known that Thai and Mandarin Chinese are typologically different in that Thai has the head-modifier constituent order whereas Mandarin Chinese has the modifier-head one. This paper aims to investigate how different constituent orders of the head vis-a-vis the modifier and vis-a-vis the complement in Thai and Mandarin Chinese bear on patterns of functional extension of the verbs meaning give in the two languages, namely, hy in Thai and gi in Mandarin Chinese. Some observations can be made regarding the functional extension patterns of hy and gi as follows: (a) the clause connector use is possible for hy but lacking for gi; (b) the passive-marking use is possible for gi but lacking for hy; (c) the gi-marked dative PP can occur both preverbally and postverbally, whereas the hy-marked one can occur only postverbally; (d) only the preverbal gi-marked dative PPs are attested in a Beijing Mandarin speech corpus; (e) the gi- marked benefactive PP can occur only preverbally; (f) the structural sche...

Investigation of mixing of plasma species in argon-water arc discharge

Summary form only given. The paper focuses on numerical simulation of mixing of plasma chemical species under extreme temperature and density gradients in the arc discharge with hybrid stabilization of an electric arc by axial argon flow and tangential water vortex (hybrid-stabilized arc). This arc is being used at present for plasma spraying and for production of syngas (CO + H2) from municipal waste or biomass.We assume one-fluid, two-dimensional, axisymmetric, unsteady, compressible and generally turbulent plasma flow, with mixing of water and argon plasma species considered using the so called combined diffusion coefficients method. Diffusion processes due to pressure, temperature and concentration gradients, and due to an external electric field are taken into account [1, 2]. Energy losses from the argonwater plasma by radiation are calculated by the partial characteristics method [3]. Turbulent effects (even though very small) are treated by Large Eddy Simulation (LES) with the Smagorinsky subgrid-scale model. Results carried out for currents 150-300 A and for argon mass flow rates 15-22.5 standard liters per minute show that: a) Mixing of plasma species is inhomogeneous under the studied conditions: argon species are dominant in the central regions of the arc, water ones in arc fringes. b) Temperature and ordinary (concentration) diffusions are the principal contributions in the argon mass diffusion flux. c) The combined ordinary diffusion is highest in the regions with steep radial temperature gradients while the combined temperature diffusion in a shear layer between argon and water plasmas.