• Journal of the Korean Electrochemical Society
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• v.23 no.1
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• pp.1-10
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• 2020

DSA (Dimensionally Stable Anode) electrodes are physically, thermally and electrochemically stable and are mainly Ti electrodes coated by Ru, Ir and Ta. DSA electrodes have been used in many industrial fields such as chlor-alkali, electrochemical water treatment, water electrolysis, etc. This review paper summarizes the study on the applications using DSA electrodes published in the recent 5 years. It suggests that the researches are intensively required on effective screening of electrodes materials, optimal designing of electrode structures and economical manufacturing of large area electrodes. It is expected that these studies will contribute to the further research and development on advanced DSA electrodes. In addition, the enhancement of DSA electrodes significantly leads to expand the type of the application using electrochemical processes in industry.

• Journal of the Korean Applied Science and Technology
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• v.12 no.2
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• pp.75-83
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• 1995

1, 3-Di(2-dodecanoylaminoethyl)-2, 7-dioxy-1, 3, 6, 8-tetraazacyclodecane[DDTD] and sorbitan monostearate(SMS) were synthesized as a main component for softner. O/W type softner(DSA) was prepared by blending of DSA, SMS, polyoxyethylene(10) castor oil, glyceryl monooleate, and polyoxyethylene(7) stearyl ether. After treatment of DSA to all cotton fabrics, the physical properties such as tear strength, crease recovery, and flexing abrasion resistance were measured. As a result of the measurement, DSA was found to be durable softner with good softness.

• Language and Information
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• v.5 no.1
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• pp.87-105
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• 2001

This paper categorizes currently available theories of focus into two major types a 'discourse structure approach'(DSA) and a 'sentence structure approach'(SSA) The former DSA is intended to refer to a type of approach that analyzes focus only in terms of the discourse structure in which a focused sentence occurs. The alternative semantics approach which is the most widely available theory of focus belongs to this The latter SSA is meant to refer to a type of theory that analyzes focus in terms of sentence-internal structure, This study supports the SSA be revealing some empirical problems of the DSA that arise is analyzing two different kinds of focus, the A-accented focus and the B-accented focus (contrastive topic), and provides a brief sketch of a comprehensive analysis of focus and contrastive topic.

• Journal of Astronomy and Space Sciences
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• v.30 no.3
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• pp.133-140
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• 2013

Most of high energy cosmic rays (CRs) are thought to be produced by diffusive shock acceleration (DSA) at supernova remnants (SNRs) within the Galaxy. Fortunately, nonthermal emissions from CR protons and electrons can provide direct observational evidence for such a model and place strong constraints on the complex nonlinear plasma processes in DSA theory. In this study we calculate the energy spectra of CR protons and electrons in Type Ia SNRs, using time-dependent DSA simulations that incorporate phenomenological models for some wave-particle interactions. We demonstrate that the time-dependent evolution of the self-amplified magnetic fields, Alfv$\acute{e}$nic drift, and escape of the highest energy particles affect the energy spectra of accelerated protons and electrons, and so resulting nonthermal radiation spectrum. Especially, the spectral cutoffs in X-ray and ${\gamma}$-ray emission spectra are regulated by the evolution of the highest energy particles, which are injected at the early phase of SNRs. Thus detailed understandings of nonlinear wave-particle interactions and time-dependent DSA simulations of SNRs are crucial in testing the SNR hypothesis for the origin of Galactic cosmic rays.

• Journal of The Korean Astronomical Society
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• v.46 no.1
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• pp.49-63
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• 2013

Nonthermal radiation from supernova remnants (SNRs) provides observational evidence and constraints on the diffusive shock acceleration (DSA) hypothesis for the origins of Galactic cosmic rays (CRs). Recently it has been recognized that a variety of plasma wave-particle interactions operate at astrophysical shocks and the detailed outcomes of DSA are governed by their complex and nonlinear interrelationships. Here we calculate the energy spectra of CR protons and electrons accelerated at Type Ia SNRs, using time-dependent, DSA simulations with phenomenological models for magnetic field amplification due to CR streaming instabilities, Alf$\acute{e}$enic drift, and free escape boundary. We show that, if scattering centers drift with the Alf$\acute{e}$en speed in the amplified magnetic fields, the CR energy spectrum is steepened and the acceleration efficiency is significantly reduced at strong CR modified SNR shocks. Even with fast Afv$\acute{e}$nic drift, DSA can still be efficient enough to develop a substantial shock precursor due to CR pressure feedback and convert about 20-30% of the SN explosion energy into CRs. Since the high energy end of the CR proton spectrum is composed of the particles that are injected in the early stages, in order to predict nonthermal emissions, especially in X-ray and ${\gamma}-ray$ bands, it is important to follow the time dependent evolution of the shock dynamics, CR injection process, magnetic field amplification, and particle escape. Thus it is crucial to understand the details of these plasma interactions associated with collisionless shocks in successful modeling of nonlinear DSA.

• Journal of radiological science and technology
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• v.25 no.1
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• pp.55-62
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• 2002

Aneurysm-mimicking findings were frequently visualized due to hemodynamical causes of dephasing effects around area of A-com artery during magnetic resonance angiography(MRA) and these kind of phenomena have not been clearly known yet. We investigated the hemodynamical patterns of dephasing effect around area of the A-com artery that might be a cause of false intracranial aneurysms on MRA. For experimental study, We used hand-made silicon phantoms of the asymmetric A-com artery as like a bifurcation configuration. In a closed circulatory system with UHDC computer driven cardiac pump system. MRA and fast digital subfraction angiography(DSA) involved the use of these phantoms. Flow patterns were evaluated with axial and coronal imaging of MRA(2D-TOF, 3D-TOF) and DSA of Phantoms constructed from an automated closed-type circulatory system filled with glycerol solution [circulation fluid(glycerol:water = 1:1.4)]. These findings were then compared with those obtained from computational fluid dynamic(CFD) for inter-experimental correlation study. Imaging findings of MRA, DSA and CFD on inflow zone according to the following: a) MRA demonstrated high signal intensity zone as inflow zone on silicon phantom; b) Patterns of DSA were well matched with MRA on trajectory of inflow zone; and c) CFD were well matched with MRA on the pattern of main flow. Imaging findings of MRA. DSA and CFD on turbulent flow zone according to the following: a) MRA demonstrated hyposignal intensity zone at shoulder and axillar zone of main inflow; b) DSA delineated prominent vortex flow at the same area. The hemodynamical causes of signal defect, which could Induce the false aneurysm on MRA, turned out to be dephasing effects at axilla area of bifurcation from turbulent flow as the results of MRA, DSA and CFD.

• The Korean Journal of Pain
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• v.32 no.4
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• pp.307-312
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• 2019

Background: The aim of this study was to clarify the topographical relationships between the dorsal scapular nerve (DSN) and the dorsal scapular artery (DSA) in the interscapular region to identify safe and convenient injection points related to DSN blockade. Methods: Thirty shoulders of embalmed Korean cadavers and 50 live subjects were used for dissection and ultrasound (US) analysis. Results: The running patterns of the DSA and DSN in the interscapular region were classified into 3 types. Type I was defined as nerves that were medial to the artery and parallel without changing location (80.0% of specimens). In type II (13.3%), the nerve and artery traversed one another only one time over their entire length. In type III (6.7%), the nerve and artery traversed one another, resembling a twist. Above the level of the scapular spine, the nerve was always medial to the artery. Below the scapular spine, the number of arteries was obviously decreased. Most of the arteries were lateral to the medial border of the scapula, except at the level of the superior angle of the scapula artery (SA). The positional tendency of the DSN toward the medial or lateral sides from the medial border of the scapula was similar. In US imaging of live subjects, the DSA was most observed at the level of the SA (94.0%). Conclusions: Results of this study enhance the current knowledge regarding the pathway of the DSN and DSA and provide helpful information for selective diagnostic nerve blocks in the interscapular region.

• Nuclear Engineering and Technology
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• v.48 no.6
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• pp.1387-1395
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• 2016

To investigate the dynamic strain aging (DSA) behavior of Alloy 617, high-temperature tensile tests were carried out with strain rates variations of $10^{-3}/s$, $10^{-4}/s$, and $10^{-5}/s$ from $24^{\circ}C$ to $950^{\circ}C$. Five flow relationships, Hollomon, Ludwik, Swift, Ludwigson, and Voce, were applied to describe the tensile true stress-strain curves, and the DSA region was defined. In describing the tensile curves, Ludwigson's equation was superior to the other equations, and the DSA region was adequately defined by this equation as plateaus at intermediate temperatures from $200^{\circ}C$ to $700^{\circ}C$. It was identified that Alloy 617 is dominated by three types of serrations, known as Types D, A+B, and C. The activation energy values for each serration type were obtained by the Arrhenius equation. By using the obtained activation energy values, the serrated yielding map and the DSA mechanism were drawn and manifested. In addition, the relationship between the tensile strength and strain rate at higher temperatures above $700^{\circ}C$ was found to be closely related to the amounts of slip lines. In the scanning electron microscope (SEM) fractographs, there was a significant difference at the low, intermediate, and high temperatures, but almost the same to the three strain rates.

• Journal of the Korean Society of Marine Environment & Safety
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• v.3 no.2
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• pp.77-84
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• 1997

For the effective treatment of shipboard sewage continuously, a non-diaphragm electrolytic treatment device using DSA type insoluble electrode, Ti/IrO2, anode and H-C metal cathode, was studied. The most effective electrolytic conditions were obtained when cell clearance, 6mm, pH 5-6 and the concentration of seawater, more than 20% as batch test results. The COD removal rate was varied in logarithmic function, showed as C=Coe-KE and the required current was E = A/QCo [A.min/mgCOD]. When the COD removal effeciency was more than 90%, the electrolytic reaction constant was 0.02.

• Journal of the Korean Society of Marine Environment & Safety
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• v.2 no.1
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• pp.67-75
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• 1996

An innovative batch electrolytic system consisted of electrolytic basin, which was equipped with DSA(Dimensionally Stable Anode) type insoluble electrode, Ti/IrO2 anode and H-C metal cathode, and flotation separator was developed for the efficient treatment of shipboard emulsified oily wastewater. The electorod cleance and current density of elecrolytic basin to ensure maximum treatment efficiency of oily wastewater was evaluated as 6 mm, 3 A/dm3, respectively. The electrolytic efficiency of oily wastewater was affected by the operationtemperature, and it means that the temperature controller to ensure the stabiity of the process is required. The conductivity in the electrolytic basin was increased with the percentage of sea water in the oily wastewater, and over 90% of treatment efficiency of oily wastewater could be obtained at 7% of sea water. The oil removal rate was increased according to the increase of the quantity of electricity, and the maximum value of electrilyic rate constant was 288 mgoil/A.min. The information obtained from this study might be used for development of an efficient continuous electrolytic system treating the emulsified oily wastewater.