• Title/Summary/Keyword: surface aging

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Conservation of Vietnam war Homecoming box in National museum of Korean contemporary history (대한민국역사박물관에 소장된 베트남전 귀국상자의 보존처리)

  • Kim, Soo Chul;Jang, Eun Jeong;Ahn, Jooyoung
    • 보존과학연구
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    • s.35
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    • pp.121-127
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    • 2014
  • The Vietnam homecoming box that has been collected in National Museum of Korean The Vietnam homecoming box that has been collected in National Museum of Korean Contemporary History got severely damaged such as rot, attached foreign substance, fading, color, wood decay. In particular, the bottom of the box was unstable state that deteriorated by pests and the left strut was severely damaged by some deep cracks and pests. The metal bands were remained on the side and bottom of the box, and all the bands were seriously corroded. On the bottom-right of the lid, black foreign matter was adhered to the surface. In the process of conservation treatments, the cleaning, filling cracks, reinforcing the bottom of the box, attaching the metal bands were proceed in order after the investigation of the state.

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The evaluation of water repellent effectiveness of natural oil treated wood (천연유지류 처리재의 발수성능 평가)

  • 이동흡;오형민;강창호;손동원;김종인
    • Journal of Korea Foresty Energy
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    • v.21 no.2
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    • pp.34-42
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    • 2002
  • This research was carried out to investigate water repellent effectiveness of natural oil treated wood. Linseed oil, castor oil, olive oil, bean oil, perilla oil and sunflower oil were used in this test. For evaluation of water repellent of natural oil treated wood, moisture absorption test, water-drop contact angle test and color difference test of accelerated decomposition by UV and water were used. The moisture absorption amount of natural oil treated wood was less than untreated wood until 3 hours, but it was increased with time, there was no big difference with oil treated wood and untreated wood after 48hours. Oil treated wood and untreated wood showed big difference on contact angle test. It was no big difference by kind and oil concentration. Natural oil treated wood did not showed stability on the weather aging test. Contact angle test could be used on evaluation of wood surface status treated with natural oil.

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A study on the expression types and aesthetic formativeness of tassels and fringe in modern bag design (현대 가방 디자인에 나타난 술 장식의 표현유형과 미적 조형성 연구)

  • Kwon, Giyoung
    • The Research Journal of the Costume Culture
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    • v.28 no.4
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    • pp.429-445
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    • 2020
  • The purpose of this study is to provide ideas for the development of bag design by analyzing the expression types and aesthetic formativeness of modern bag design using tassels and fringe given the newtro trend pursuing analog sensitivity in modern society. The methods and scope of this study are as follows. First, the related literature and internet data were reviewed in order to examine the expression types and characteristics of the bags of the West and East. Next, the definition and characteristics of tassel and fringe decoration in terms of the history of clothing were analyzed. Finally, the expression types and aesthetic formativeness of tassels and fringe were derived through the analysis of modern bag design shown in the fashion collections since 2010. The bags decorated with the tassels and fringe bring a variety of visual effects depending on the attachment position, direction and material composition, concentrating the gaze and radiating original style. In this study, the expression of tassels and fringe in modern bag design was classified into three types: surface decoration, shape variability, and object combination. Next, the aesthetic formativeness of modern bag design using tassels and fringe as decorative elements appeared through the mixture of heterogeneous materials and playfulness through imagination, exaggeration through extension of length and volume, and retro characteristics through reinterpretation of tradition. This study is expected to contribute to creative ideas of modern bag design which requires a global sense, which has been used in various cultures for a long time.

Optical Microscopic Image Analysis for Damaged GFRP Rebar by Alkali and High Temperature Exposures (알칼리와 고온노출에 의한 GFRP 보강근 손상에 대한 현미경분석 연구)

  • Bae, Jung-Myung;Moon, Do-Young;Park, Cheol-Woo;Park, Young-Hwan
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.21 no.2
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    • pp.53-59
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    • 2017
  • In this experimental study, the characteristic of damages on GFRP rebar exposed to high temperature only and immerged in alkaline solution after the exposure to high temperature was analyzed through microscopic image analysis. The found microcrack and pores in resin matrix were quantitatively compared if there was effect of pre-exposure to high temperature. The damages, such as microcrack and pores in resin matrix, by alkali exposure were mainly found in rebar surface. On the other hand, the pores caused by high temperatures were extensively found in a section and had greater width than those caused by the alkali exposure. In results of the quantitative comparison, the accumulated length and widths of microcrack and pores in resin matrix in pre-exposed GFRP rebar to high temperature were respectively 1.5 and 1.4 times of those in the GFRP rebar only immerged in alkali solution. Therefore, the deterioration of resin matrix by the alkali exposure could be accelerated due to the pre-exposure to high temperature.

The biocompatibility and mechanical properties of plasma sprayed zirconia coated abutment

  • Huang, Zhengfei;Wang, Zhifeng;Yin, Kaifeng;Li, Chuanhua;Guo, Meihua;Lan, Jing
    • The Journal of Advanced Prosthodontics
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    • v.12 no.3
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    • pp.157-166
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    • 2020
  • PURPOSE. The aim of this study was to evaluate the clinical performance and reliability of plasma sprayed nanostructured zirconia (NSZ) coating. MATERIALS AND METHODS. This study consisted of three areas of analysis: (1) Mechanical property: surface roughness of NSZ coating and bond strength between NSZ coating and titanium specimens were measured, and the microstructure of bonding interface was also observed by scanning election microscope (SEM). (2) Biocompatibility: hemolysis tests, cell proliferation tests, and rat subcutaneous implant test were conducted to evaluate the biocompatibility of NSZ coating. (3) Mechanical compatibility: fracture and artificial aging tests were performed to measure the mechanical compatibility of NSZ-coated titanium abutments. RESULTS. In the mechanical study, 400 ㎛ thick NSZ coatings had the highest bond strength (71.22 ± 1.02 MPa), and a compact transition layer could be observed. In addition, NSZ coating showed excellent biocompatibility in both hemolysis tests and cell proliferation tests. In subcutaneous implant test, NSZ-coated plates showed similar inflammation elimination and fibrous tissue formation processes with that of titanium specimens. Regarding fatigue tests, all NSZ-coated abutments survived in the five-year fatigue test and showed sufficient fracture strength (407.65-663.7 N) for incisor teeth. CONCLUSION. In this study, the plasmasprayed NSZ-coated titanium abutments presented sufficient fracture strength and biocompatibility, and it was demonstrated that plasma spray was a reliable method to prepare high-quality zirconia coating.

Basic Insulation Characteristics of Conduction-Cooled HTS SMES System (전도냉각 고온초전도 SMES 시스템의 기초절연 특성)

  • Choi Jae-Hyeong;Kwang Dong-Soon;Cheon Hyeon-Gweon;Kim Sang-Hyun
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.55 no.8
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    • pp.404-410
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    • 2006
  • Toward the practical applications, on operation of conduction-cooled HTS SMES at temperatures well below 40[K] should be investigated, in order to take advantage of a greater critical current density of HTS and considerably reduce the size and weight of the system. In order to take advantage of a greater critical current density of high temperature superconducting (HTS) and considerably reduce the size and weight of the system, conduction-cooled HTS superconducting magnetic energy storage (SMES) at temperatures well below 40[K] should be investigated. This work focuses on the breakdown and flashover phenomenology of dielectrics exposed in air and/or vacuum for temperatures ranging from room temperature to cryogenic temperature. Firstly, we summarize the insulation factors of the magnet for the conduction cooled HTS SMES. And Secondly a surface flashover as well as volume breakdown in air and/or vacuum with two kind insulators has been investigated. Finally, we will discuss applications for the HTS SMES including aging studies on model coils exposed in vacuum at cryogenic temperature. The commercial application of many conduction-cooled HTS magnets, however, requires refrigeration at temperatures below 40[K], in order to take advantage of a greater critical current density of HTS and reduce considerably the size and weight of the system. The magnet is driven in vacuum condition. The need to reduce the size and weight of the system has led to the consideration of the vacuum as insulating media. We are studying on the insulation factors of the magnet for HTS SMES. And we experiment the spacer configure effect in the dielectric flashover characteristics. From the results, we confirm that our research established basic information in the insulation design of the magnet.

Development of Easily Chewable and Swallowable Pan-fried Flat Fish for Elderly (가자미 구이 저작·연하 용이 노인식 개발)

  • Kim, Soojeong;Joo, Nami
    • The Korean Journal of Food And Nutrition
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    • v.28 no.1
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    • pp.153-159
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    • 2015
  • This study was conducted to develop food for the elderly, which are well-shaped and easy to chew and swallow. The amounts of water and gelatin were adjusted to facilitate breaking down of the food with the tongue. In the aging society, it is necessary to support the development of a variety of products that can ease the intake functions of swallowing and chewing, while complementing with the essential nutrients supplements; such products can be actively commercialized in the elderly industry. Various types of food, for elderly with difficulties in chewing and swallowing, were used for sensory assessment. Sensory panel consisted of 10 dietitians (10 women) in nursing care facilities. The sensory optimal composite recipes were determined by central composite design (CCD). The sensory measurements were significantly different in the appearance (p<0.01), saltiness (p<0.01) and overall quality (p<0.01). The optimum formulation of pan fried flat fish, calculated by numerical and graphical method, was 8.54 g of salt and 6.34 g of olive oil. Moisture content, hardness, and adhesiveness of pan fried flat fish were 84.77%, 250, and -1.20, respectively. The result showed that easily chewable and swallowable pan fried flat fish for the elderly will have sufficient competitiveness, considering its safety, taste, and preference. This study may provide the basic materials for the development of easily chewable and swallowable foods for elderly.

The applicable evaluation of biodegradable polymer coated-mulching paper for afforestation seedlings (생분해성 고분자 코팅 조림묘목용 mulching mat 원지의 적용성 평가)

  • Lee, Geum-Ja;Yoo, Yeong-Jeong;Ko, Seung-Tae;Kim, Hyoung-Jin
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.42 no.1
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    • pp.54-63
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    • 2010
  • Recently, as the function of largest supplier of biomass for "low carbon green growth", the necessity for systematic management of afforestation areas is emphasizing. The forestation of seedling, besides the afforestation cost itself, is required some additional follow-up management costs, like mowing and fertilizing of forestation area, and removal of bindweed. The mulching mat for afforestation seedlings is available for rooting of little seedlings as well as initial forestation expenses. Mulching technique is also used to control soil temperature and moisture by covering the surface of ground. In this study, the paper based-mulching film coated with biodegradable polymer and functional additive was specially produced using laboratory bar coater, and analyzed for its degradable behavior. Coating colors were prepared by dissolving PE (polyester) 80 % and PLA(polylactic acid) 20 % in chloroform and finally applied to handsheet prepared by preceding study conditions. Base paper and polymer-coated paper were artificially aged by 2 kinds of degradation methods, which are soil degradation by microorganism and light degradation by 257 nm UV wavelengths. Strength property, oxidation index and morphological property were evaluated by reduction rates of tensile strength, FTIR spectra ratio of carboxyl and carbonyl group and SEM micrograph. As these results, polymer coated-paper was superior to base paper in degradation behaviors, having results with lower reduction rate of strength properties.

KT-1 Market Assessment Study (KT-1 Market Assessment 연구)

  • Je, Sang-Eon;Kim, Do-Jun;Lee, Jae-Myong;Park, Chan-Woo;Cho, Tae-Hwan;Kim, Jin-Seok;Lee, Jin-Gyun
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.36 no.4
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    • pp.368-374
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    • 2008
  • The basic Trainer Aircraft of The Korean Air force KT-1/KO-1, which was designed and developed by Korean Technology has been a primary candidate as a replacement for the aging basic trainer or armed version for surface support operation for the nations such as Mexico, Philippine, Turkey, Venezuela and etc. In this study, competitors for the same class aircraft and the present operational status of the basic trainer of the world were identified and the fade out periods were also predicted. The result of this market analysis showed the required number of aircraft by the year 2025 for 33 countries as 4500. The exportable number of KT-1 aircraft was predicted considering the political/diplomatical environments, economic environment and also by the ability of producing same class aircraft of the country.

A STUDY OF DENIAL ARCH FORM IN NORMAL OCCLUSION (정상교합의 치열궁형태에 관한 연구)

  • Cho, Joo-Hwan;Lee, Ki-Soo
    • The korean journal of orthodontics
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    • v.14 no.2
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    • pp.249-261
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    • 1984
  • This study was to investigate the fitness of the dental arch line to the parabola, and to estimate correlation between the parabola and some ratios of the dental arch measurements. The sample was consisted of the 64 plaster casts showing normal occlusion which was taken from males and females of Korea, aging from 15 to 18 years. The photos of occlusal surface of the plaster casts were taken, and 38 landmarks on the film were selected. The 3 dental arch lines on each dental arch were imaged. One is the dental arch line passing the points of the most buccal surfaces of the teeth, another is that passing the buccal cusp tips of the posterior teeth and the incisal edges, and the other is that passing the midpoints of the teeth. The landmarks on the film were digitized, and measurements and statistics were performed by the IBM computer. The results were as follows; 1. The fitness of the dental arch to the parabola was very good. The fitness of thor upper dental arch was above $91\%$, and that of the lower dental arch was $93\%$. 2. The dental arch line passing the points of the most buccal surfaces of teeth was best fit to the parabola, the buccal cusp tip arch line and the midpoint arch line in order. 3. Correlation between the ratio of oblique molar dental height to molar width and the parabola was very high. 4. The ratio of oblique molar dental height to molar width was devided into 4 groups by the quartiles, and mean parabolic equations and curves were calculated and drawn.

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