• Progress in Superconductivity and Cryogenics
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• v.19 no.2
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• pp.25-28
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• 2017

In superconducting coil applications particularly in wet wound coils, coated conductor (CC) tapes are subjected to different type of stresses that could affect its electromechanical transport property. These include hoop stress acting along the length of the CC tape and the Lorentz force acting perpendicular to the CC tape's surface. Since the latter is commonly associated with the delamination problem of multi-layered REBCO CC tapes, more understanding and attention on the delamination phenomena induced in the case of coil applications are needed. Difference on the coefficient of thermal expansion (CTE) of each constituent layer of the CC tape, the bobbin, and the impregnating materials is the main causes of delamination in CC tapes when subjected to thermal and mechanical cycling. In the design of degradation-free superconducting coils, therefore, characterization of the delamination behaviors including mechanism and strength in the multi-layered REBCO CC tapes becomes a critical issue. Various trials to increase the delamination strength by improving interface characteristics at interlayers have been performed. In this study, in order to investigate the influences of laser cleaning and Ag annealing treated at the substrate side surface, transverse tensile tests were conducted under different sample configurations using $4.5mm{\times}8mm$ upper anvil. The mechanical delamination strength of differently processed CC samples was examined at room temperature (RT). As a result, the Sample 1 with the additional laser cleaning and Ag annealing processes and the Sample 2 with additional Ag annealing process only showed higher mechanical delamination strength as compared to the Sample 3 without such additional treatments. Sample 3 showed quite different behavior when the loading direction is to the substrate side where the delamination strength much lower as compared to other cases.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.452-455
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• 2017

As the number of high - rise buildings has increased recently, this research society has become interested in the method of cleaning the external wall required. When cleaning these areas, an accident occurs every year when a person uses dangerous manual labor using a gondola. The main goal of this work is to enable people to manipulate the robot with simple operation without dangerous manual operation when working in a vertical structure. As the altitude increases, the concept of the mechanism attaching to the vertical structure while enduring the external resistance in the increase of the wind strength is applied, and the additional attachment device is attached to the end of the leg based on the existing four- According to the control, the development result of the robot having the function of detachable to the glass is presented.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.1
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• pp.85-95
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• 2019

This work shows how to design a robot structure and to control to overcome obstacles while traveling through ducts of various diameters and shapes by three-legged robot. Circuits are centered in the body to connect the three wheel bodies that are driven around the center body with the 4-section slider link structure. Also, the springs are used to contract and expand the robot legs so that it can be caparable of various environments. Geared motor, spring, and belt were selected based on the static and dynamic calculation to be suitable to horizontal and vertical travels. The center body is equipped with a camera and the distance sensors, and a control algorithms are implemented so that it can be successfully performed in L-type and T-type ducts. Using UWB modules and trilateration algorithm, the location of the duct-cleaning robot inside the duct could be identified successfully.

• Journal of Mechanical Science and Technology
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• v.20 no.1
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• pp.1-12
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• 2006

This work reviews the effects of catalyst formulation and exhaust gas composition on soot oxidation in CDPF (Catalytic Diesel Particulate Filter). DOC's (Diesel Oxidation Catalysts) have been loaded with Pt catalyst (Pt/$Al_{2}O_3$) for reduction of HC and CO. Recent CDPF's are coated with the Pt catalyst as well as additives like Mo, V, Ce, Co, Fe, La, Au, or Zr for the promotion of soot oxidation. Alkali (K, Na, Cs, Li) doping of metal catalyst tends to increase the activity of the catalysts in soot combustion. Effects of coexistence components are very important in the catalytic reaction of the soot. The soot oxidation rate of a few catalysts are improved by water vapor and NOx in the ambient. There are only a few reports available on the mechanism of the PM (particulate matter) oxidation on the catalysts. The mechanism of PM oxidation in the catalytic systems that meet new emission regulations of diesel engines has yet to be investigated. Future research will focus on catalysts that can not only oxidize PM at low temperature, but also reduce NOx, continuously self-cleaning diesel particulate filters, and selective catalysts for NOx reduction.

• Design & Manufacturing
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• v.15 no.4
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• pp.57-64
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• 2021

In recent materials industry, researches on the technology to manufacture super hydrophobic surface by effectively controlling the wettability of solid surface are expanding. Research on the fabrication of super hydrophobic surface has been studied not only for basic research but also for self-cleaning, anti-icing, anti-friction, flow resistance reduction in construction, textile, communication, military and aviation fields. A super hydrophobic surface is defined as a surface having a water droplet contact angle of 150 ° or more. The contact angle is determined by the surface energy and is influenced not only by the chemical properties of the surface but also by the rough structure. In this paper, maskless lithography using DMD, electro etching, anodizing and hot embossing are used to make the polymer resin PMMA surface super hydrophobic. In the fabrication of microstructure, DMDs are limited by the spacing of microstructure due to the structural limitations of the mirrors. In order to overcome this, maskless lithography using a transfer mechanism was used in this paper. In this paper, a super hydrophobic surface with micro and nano composite structure was fabricated. And the wettability characteristics of the micro pattern surface were analyzed.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1996.04a
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• pp.36-41
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• 1996

Drugs mean not only medicines but also poisons, pesticides, food additives, cosmetics, cleaning agents, environmental pollutants and so on, which are normally considered foreign to the body, It is important to know what happens to these drugs when they get into the body. In the past the metabolic changes of drugs had been referred to as “detoxication mechanism”, but since there are many instances in which drugs are converted in the body to more active substances. Thus, metabolism of drugs is responsible for activation and inactivation of the drugs in the body. The major reactions in drug metabolism are oxidation, reduction, hydrolysis and conjugation. Of these four areas, most of the attention had been focused on the oxidation. Therefore, in contract of ample literatures on drug-oxidizing enzymes, there were relatively few reports on drug-reducing enzymes. In recent years, however, the reduction has received an increasing interest due to its pharmacological or toxicological significance. The present lecture is organized keeping with a focus on drug-reducing enzymes which have been explored by us and by other groups.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.822-825
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• 2004

Corrosion of reinforced concrete structures in marine environment is one of the most important mechanism of deterioration. The conventional repair techniques of concrete structure damaged by chloride attack consist of removing damaged concrete, cleaning rebar and patching with cement-based materials. However, recently, this method was considered to be ineffective for marine concrete structure in tidal zone. It is necessary to select proper repair method for domestic marine environment which shows broad tidal zone. This paper reports the results of repair of highway concrete bridge damaged by chloride attack in domestic marine environment.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.786-789
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• 2004

Corrosion of reinforced concrete structures in marine environment is one of the most important mechanism of deterioration. However, conventional rehabilitation techniques in tidal zone, which consist of removing delaminated areas of concrete, cleaning affected steel and patching with portland cements mortar, have proven to be ineffective for marine structures. Also, repairs are often repeated every several years. The purpose of this report is to announce appropriate repair method of highway bridge damaged by chloride attack in marine environment (application of cathodic protection) using FRP and antiwashout underwater mortar.

• KIEE International Transactions on Electrophysics and Applications
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• v.4C no.1
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• pp.10-14
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• 2004

A large area electron beam generator has been developed for industrial applications, for example, waste water cleaning, flue gas treatment, and food pasteurization. The operational principle is based on the emission of secondary electrons from the cathode when ions in the plasma contact the cathode, which are accelerated toward the exit window by the gradient of the electric potential. Conventional electron beam generators require an electron beam scanning mechanism because a small area thermal electron emitter is used. The electron beam of the large area electron beam generator does not need to be scanned over target material because the beam area is considerable. We have fabricated a large area electron beam generator with peak energy of 200keV, and a beam diameter of 200mm. The electron beam current has been investigated as a function of accelerating voltage and distance from the extracting window while its radial distribution in front of the extracting window has been also measured.

• Journal of environmental and Sanitary engineering
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• v.13 no.3
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• pp.141-147
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• 1998

Under high temperature and high pressure, cyanogen disinter gration distruction mechanism brought followings results through continuous plug flow reactor system. 1. The temperature was a important reacting factor in cyanogen disintegration. Over $612.8^{\cird}K$ high disintegration rate or 99.99% was shown even under $2000{\;}mg/{\ell}$ cyanogen density. 2. The conditions of cyanogen disintegration was gained through experimenting the supercrietical condition of water in basic. To gain 99.99% disintegration rate under $1000{\;}mg/{\ell}$ early cyanogen density, the pressure showed 52.8 seconds at $523^{\cird}K$ and 84.2 atm and gained $0.56{\;}mg/{\ell}$ operating density. 3. Here is the reaction velocity formula of cyanogen disintegration by hydrolysis: This formula indicates the high possibility of cyanogen disintegration within a short time. And it also implys the potential possibility on treating NBDICOD and the technology in developing the environment cleaning progress as small size automatic controlling equipment.