• Textile Coloration and Finishing
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• v.16 no.5
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• pp.28-34
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• 2004

The polarizing film application exploits the unique physicochemical properties between PVA(Poly vinyl alcohol) film and CTA(Cellulose triacetate) film. However, hardly any research was aimed at improving the adhesion characteristics of the CTA film by radio frequency(RF) plasma treatment at argon(Ar) gaseous state. In this report, we deal with surface treatment technology for protective CTA film developed specifically for high adhesion applications. After Ar plasma, surface of the films is analyzed by atomic force microscopy(AFM), roughness parameter and peel strength. Furthermore, the wetting properties of the CTA film were studied by contact angle analysis. Results obtained for CTA films treated with a glow discharge showed that this technique is sensitive to newly created physical functions. The roughness and peel strength value increased with an increase in treatment time for initial treatment, but showed decreasing trend for continuous treatment time. The result of contact angle measurement refer that the hydrophilicity of surface was increased. AFM studies indicated that no considerable change of surface morphology occurred up to 3 minutes of treatment time, but a considerable uneven of surface structure resulted from treating time after 5 minutes.

• Proceedings of the Materials Research Society of Korea Conference
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• 2007.11a
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• pp.101.2-101.2
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• 2007

• Proceedings of the Korean Ceranic Society Conference
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• 2004.04b
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• pp.38.1-38.1
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• 2004

• Proceedings of the Korean Vacuum Society Conference
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• 2002.06a
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• pp.197-197
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• 2002

• Journal of the Korean Society of Costume
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• v.57 no.8
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• pp.14-23
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• 2007

The purpose of this study was to investigate the present condition of cold protective clothing for mailman, to improve its design in movement, fitness, and other functions, and supply basic data for its performance evaluation. The results are as follows : The 46.60% of those questioned did not satisfy current clod protective clothing fer mailman. Especially, they considered dissatisfactory in properties such as waterproof, comfort, activity, and sweat absorption. The newly developed cold protective clothing is two-piece style composed of jacket and pants. Both jacket and pants are composed of inner and outer clothing individually. In both jacket and pants, their outer clothing's material was waterproof, windproof, and breathable shell fabric on which PTFE film laminated and their inner clothing's material was 100% polyester Polar polis to have better insulation property. The jacket has attachable cap which can be used as rain gear and set-in sleeve with stand collar. It also had big outside patch pockets and side seam pockets to ensure enough storage space. The pants have knee pads to give free movement to knees and slant side pockets. Inner clothing of both jacket and pants can be worn during working inside without out clothing. Insulation of the newly developed cold protective clothing was not better than current one except right hand, left hand and left foo. It is considered that is because thickness of material is the most important factor to influence insulation.

• Corrosion Science and Technology
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• v.4 no.4
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• pp.121-129
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• 2005

Basic design concept of the future steel structure requires environmental compatibility and maintenance free capability to minimize economic burdens. Recent trends in alloy design for advanced weathering steel include addition of various alloying elements which can enhance formation of stable and protective rust layer even in polluted urban and/or high $Cl^{-}$ environment. The effects of Ca, Ni, W, and Mo addition on the corrosion property of Ca-modified weathering steel were evaluated through a series of electrochemical tests (pH measurement and electrochemical impedance spectroscopy: EIS) and structural analysis on rust layer formed on the steel surface. Ca-containing inclusions of Ca-Al-Mn-O-S compound are formed if the amount of Ca addition is over 25 ppm. Steels with higher Ca content results in higher pH value for condensed water film formed on the steel surface, however, addition of Ni, W, and Mo does not affect pH value of the thin water film. The steels containing a high amount of Ca, Ni, W and Mo showed a dense and compact rust layer with enhanced amount of ${\alpha}-FeOOH$. Addition of Ni, W and Mo in Ca-modified weathering steel shows anion-selectivity and contributes to lower the permeability of $Cl^{-}$ ions. Effect of each alloying element on the formation of protective rust layer will be discussed in detail with respect to corrosion resistance.

• Corrosion Science and Technology
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• v.4 no.3
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• pp.75-80
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• 2005

This work dealt with the evaluation of galvanic corrosion rate in a corrosion cell having annular gap of 0.5 mm between carbon steel 1018 and alloy 600 as a function of temperature and boron concentration. Temperature and boron concentration were ranged from 110 to 300 $^{\circ}C$ and 2000~10000 ppm, respectively. After the operating temperature of the corrosion cell where the electrolyte was injected was attained at setting temperature, galvanic coupling was made and at the same time galvanic current was measured. The galvanic corrosion rate decreased with time, which was described by corrosion product such as protective film as well as boric acid deposit formed on the carbon steel with time. From the galvanic current obtained as a function of temperature and boron concentration, it was found that the galvanic corrosion rate decreased with temperaturewhilethe corrosionrate increasedwith boronconcentration. The experimental resultsobtained from galvanic corrosion measurement were explained by adhesive property of corrosion product such as protective film, boric acid deposit formed on the carbon steel wall and dehydration of boric acid to be slightlysolubleboric acid phase.Moreoverthe galvaniccorrosionrate calculatedusing initialgalvaniccoupling current instead of steady state coupling current was remarked, which could give us relatively closer galvanic corrosion rate to real pressurized water reactor.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.15 no.6
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• pp.9-15
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• 2016

Due to material-specific vulnerabilities, the surfaces of the liquid crystal glasses used in mobile phones can crack easily, with even the smallest cracks undergoing propagation. To protect the glass surfaces, films are attached to the surfaces during the mobile phone production process. However, after machining the liquid crystal, removal of the film on the liquid crystal surface using chemical and mechanical methods is required. In this research, a peeling apparatus was developed for removing the films attached to liquid crystal surfaces during the production process. Mechanical attachment and design automation through experimentation and finite element modelling were performed to confirm the validity of the design.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.10 no.1
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• pp.57-61
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• 1980

In dental roentgenograph it is of mutual benefit to the patient and the dentist to use the minimum amount of radiation capable of producing roentgenograms with maximum interprtive informations. Recent increases in the number of diagnostic x-ray examinations made in this country have caused attention to be paid to the quantity of radiation delivered to the population and operator. The purposes of this study was to assess the quality of dental x-ray units, the amount of films, the average processing procedures and the radiation protection methods in korea. The results were as following: 1. Most of radiation generating system were used in low voltage such as 60Kvp, 10㎃. 2. High sensitivity films such as 'D' group of Kodak or Rinn were mainly used and average 14.7 films used per weeks. 3. Some dentists practiced visual processing technic in simple dark room, and others used instant films. 4. 68.26% of patient held the film themselves, but 27.30% were assisted by dentists film holding. 5. In radiation protection method, 7.85% of dentists had protection equipments such as protective barrier, 2.73% wore protective apron, 27.9% made it a rules to avoid beam, and 7.51% used to maintain a distance from the radiation source.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.6
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• pp.915-919
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• 2012

In constructing all kinds of equipment and steel structure, parts with discontinuities such as weld defects formed in the welded structure can generate fatigue cracks that results in damage or accidents. In this study, weld zones are investigated with X-rays and the latent images are put on film. Weld zone defects can be verified by developing the film. As weld defects are investigated by radiographic testing and correlated with the welding condition, more appropriate welding conditions can be found. According to the result of X-ray radiographic inspection of butt welding ATOS 80 high-strength steel with a thickness of 12mm, the best conditions for welding without creating weld defects are 4 weld-passes, a protective gas of 20% $CO_2$ and 80% Ar, a protective gas flow of 20L/min, a welding current of 200A, an arc voltage of 24V, a welding speed of 14.4cm/min, a welding rod angle of $50^{\circ}$, a welding gap of 5 mm with a ceramic base, and sand pre-heating to $160^{\circ}$ Celsius prior to welding.