• The Journal of Korean Academy of Prosthodontics
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• v.40 no.3
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• pp.275-286
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• 2002

Statement of problem. Surface alteration of the implant screws after function may be associated with mechanical failure. Theses metal fatigue appears to be the most common cause of structural failure. Purpose. The purpose of this study was to evaluate surface alteration of the implant screws after function through the examination of used and unused implant screws in SEM(scanning electron microscope). Materials and methods. In this study, abutment screws(Steri-oss, 3i), gold retaining screw(3i) and titanium retaining screw(3i) were retrieved from patients. New, unused abutment and retaining screws were prepared for control group. Each of the old, used screws was retrieved with a screwdriver. And retrieved implant complex of Steri-oss system was prepared for this study. Then, SEM investigation and EDS analysis of abutment and retaining screws were performed. And SEM investigation of cross-sectioned sample of retrieved implant complex was performed. Results. In the case of new, unused implant screws, as maunfactured circumferential grooves are regularly examined and screw thread are sharply remained. Before ultrasonic cleansing of old, used implant screw, a lot of accumulation and corrosion products were existed. After ultrasonic cleansing of old, used implant screws, circumferential grooves as examined before function were randomly deepened and scratches increased. Also, dull screw thread was examined. More surface alterations after function were examined in titanium screw than gold screw. And more surface alteration was examined when retrieved with driver than retrieved without driver. Conclusions. These surface alteration after function may result in the screw instability. Regularly cleansing and exchange of screws was recommended. We recommend the use of gold screw rather than titanium screw, and careful manipulation of the driver.

• Journal of Conservation Science
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• v.35 no.1
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• pp.19-31
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• 2019

To study the cleaning effects and post-treatment stability assessment of various methods of cleaning textiles with metal thread, six naturally-soiled historical textiles with metal thread were investigated at the Metropolitan Museum of Art, New York. Prior to the cleaning of fabricated gold, silver, and copper thread that had been glued onto a paper substrate, the artificial deterioration was carried out in a controlled environment with light(UV and daylight), and temperature and humidity factors which would weaken and damage the samples. A synthetic soil mixture was applied to the samples to imitate soil found on the historic and archaeological textiles with metal thread; the cleaning effect and post-treatment assessment were investigated by use of three textile cleaning methods: mechanical cleaning, wet cleaning, and solvent cleaning. While investigating the naturally-soiled textiles with metal thread, it was determined that the soil colors and sizes of contaminating particles of each textile were different due to the diversity of original environmental factors and conditions. After cleaning with kneaded rubber, Stoddard solvent, n-decane or n-hexane, a bright, clean effect was apparent. Kneaded rubber was successful in picking up both large and small particles, but its stickiness caused some of the metal leaf to peel off. Stoddard solvent produced a good cleaning effect, but after use of n-hexane and n-decane in the cleaning process, a white layer of residue remained on the textile's surface. Wet cleaning was not effective and the rapid humidity changes between wet and dry conditions caused the edges of the paper substrate to lose their original shape.

• Journal of the Korean Society of Costume
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• v.50 no.8
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• pp.5-16
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• 2000

This study attempts to examine compound weave among silk fabrics of Cho-Sun Dynasty. These silk fabrics have colorful patterns. They can be classified into two types by their texture structure one is called polychrome woven silk of which structure is plain or twill fabric : another is called satan damask of which structure is stain fabric. Their texture structure consist of warp and weft. In addition. there are other types of warp and weft for pattern structure ; various twill structures were used for patterns. A variety of colorful threads, including gold and silver ones. are used fur patterns in them. The brocaded-type fabric was primarily developed during Won Era of China. It was most developed in Ko-Rye Kingdom. During that era flat strip was used the most but its length was usually not long enough to finish one pattern. However, wrapped thread was increasingly used during the middle and later period of Cho-Sun Dynasty due to the development of weaving technology for gold thread. The brocaded-type fabric was produced in Korea and it was also Imported from China according to some record. There are some domestic empirical documents that show the names of imported Satin Samite, Brocaded satin and these are good evidence to prove the nationwide use of the cloth during Cho-Sun Dynasty. The density ratio of warp and weft is almost same except Samite in the third and Satin with flower motif in the second period is most density among them. C·F of Brocaded satin with Mang motif in the third period values the highest price. Brocaded satin, used with both gold and silver threads, is thickest.

• Journal of Conservation Science
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• v.34 no.4
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• pp.245-257
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• 2018

To investigate the deterioration of textiles with metal thread, I surveyed 40 textile objects, dating from the 11th to the 19th century from Korea, China, Japan, and Central Asia at the Metropolitan Museum of Art, New York. This survey included various types, widths, and thicknesses of metal thread. In addition, deterioration was examined under the microscope and color information was collected using the spectrophotometer. While investigating metal thread in the collections, I fabricated 12 different types of metal samples with metal leaf(24K gold, silver, and copper leaf), adhesive (hide animal glue and a mixture of hide animal glue and iron oxide red), and paper substrate(Korean mulberry and Taiwanese kozo paper). The accelerated deterioration process of those fabricated samples was carried out using a light box(UV and daylight), and a humidity cabinet. In the light experiment with blue scales textile fading card(aka, blue wool standard), the metal leaf began to peel off during the deterioration process with 756,000 lux-hours UV and daylight. In the temperature and humidity experiment, I could observe the reddish tarnish on copper, and some part of it began to peel off. Color reading on the light exposed samples showed that the degree of color change on the surface follows the amount of exposure as it increased over time. On the other hand, color change on the samples after artificial deterioration using temperature and humidity factors showed random change of color with occasional spikes. Distortion of original shape worsened in the samples exposed to temperature and humidity.

• The Research Journal of the Costume Culture
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• v.8 no.5
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• pp.638-647
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• 2000

The purpose of this study is to discover the interrelationship between modern costumes and Seung-Hee Choi's dancing costumes in 1930s. Seung-Hee Choi, who was a dancing pioneer in Korea, introduced the modern dancing costumes for the first time in Korea. The results are as followed ; First, we can find Eroticism in Choi's dancing dress. Choi's dancing costume had used gold thread, silver thread, spangle, see-through and a half-naked body clothing that decorated with beads and cords. It is similar to modern costumes in ubjet mtter, silhouette, design, and so on. Second, the influence of Futurism was in her dancing costumes, that is, it represented asymmetry designs and rectilineal figures. Third, not only beauty but also a Functionalism was expressed in her dancing costumes. Functional beauty was shown through bias cut, pleats, slit, and so on.

• 보존과학연구
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• s.19
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• pp.61-74
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• 1998

Conservation Treatment Process 1. Inlaying is observed at the back and head of a sword to grasp the inner structure of relics by photographing X-ray. 2. After removing rust of surface, inlaying emerge. 3. After hardening, inlaying emerge to magnetite layer by standing Scapel and Vibrotool throught microscope. Charcterization 1. Most of domestic inlaying become designed to the head of a sword but this inlaying become designed to gold inlaying to the back of a sword. 2. Inlaying is the technique to groove V-shape on the surface of relice and to put gold thread in.

• Journal of the Korean Society of Costume
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• v.58 no.3
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• pp.123-130
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• 2008

Symbolizing holiness, wealth and power, golden color was most effective to express the absolute power of royal family and aristocratic society as well as the beauty of magnificent and brilliant authority. Such golden color was understood as the artistic color formed in the dictatorial society as well as the society under the rule of absolute monarch. Thus, it has been used in the costume that symbolizes nobleness, holiness, brilliancy, ethnicity and future-oriented property. In this sense, the image of golden color shown in contemporary fashion was analyzed as follows in this research: First, showing the future-oriented image, golden color expresses avant-garde, cyber and cosmic future-oriented image by using diverse new materials which introduce the state-of-the-art technology sense in addition to metallic textile. Second, getting hint from the ethnic costume of many countries around the world such as brilliant embroidery using golden-thread, ornament with exaggerated technique such as gold foil, mark and character in peculiar tint, the ethnic image of golden color expressed the peculiar color or materials of ethnic costume, handicraft details, etc in golden color. Third, since golden color is expressed in ostentatious image to which elegance and luxuriousness that looks like the work of haute-couture costume of royal family or sensuality that voluptuously expresses the beautiful body line of women are added, the viewers are enchanted or attracted.

• The Journal of Korean Academy of Prosthodontics
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• v.40 no.3
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• pp.246-261
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• 2002

The screw loosening is one of the complications that happen frequently in dental implant prostheses. The purpose of this study was to evaluate the changes of reverse/loosening (opening) torque of the screw according to the surface modifications by sandblasting and 24K gold electroplating as well as to determine the possibility of the clinical use of a washer in dental implant. The reverse torque of 4 experimental conditions(control, sandblasted, use of washers, electroplasted) was measured by digital torque gauge (Model MGT50Z, Mark-10 Corp., 458 West John Street Hicksville, NY 11801 USA). Electronic torque controller (Nobel Biocare DEA 020) was used in fastening the gold screws into abutment replicas. Mixed Linear Model Analysis method was used for statistical analysis. To examine the changes of screw thread surface, microphotographs were taken by Olympus PME-3 metallurgic microscope (Olympus Optical Co. Ltd., Tokyo, Japan). Within the limitations of this study, the following results were drawn: 1. The surface modifications of the gold screws and the use of a washer have significantly affected the reverse torque value compared to the control group (P<0.01). 2. Sandblasting and electroplating treatments demonstrated significantly higher reverse torque value than that of control group. 3. The use of a washer may be one of the useful clinical methods that prevent the screw loosening. However, further studies are necessary for the material selection and design of the washer.

• Journal of the Korean Society of Costume
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• v.58 no.5
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• pp.153-165
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• 2008

The methods used in determining the weaving period of the textiles comprises not only radiocarbon dating but also discrimination of the motif and the textile structure. This study surveys the variation of the structure and the characteristics of the patterned textile of the Joseon dynasty to determine the weaving period. The number of twill gradually decreased in the Joseon dynasty while satin weave became more popular and the non-patterned twill almost vanished after 1600 A.D. The patterned plain weave was started to weave from the beginning of the Joseon dynasty but this has been shifted to twill, satin weave, floated weave, or the textiles with combined techniques more than 2 kinds after 1800 A.D. For the twist of threads, the number of the fabrics with Z-twisted thread in the warp and the non-twisted thread in the weft showed peak in 1600 A.D. and gradually decreased afterward. After 1600 A.D., the textile without twist became general trend.The satin weave started to appear with the 5-end satin in the beginning of the Joseon dynasty but the 8-end satin started to appear from the middle of 17th century and got more popularity with time. At the same period, the patterned textile on the ground of the satin weaved with the different techniques from the earlier period started to appear. The twist of the satin in the 1600 A.D. showed similar trends as twill, this general trend resulted from the fact that the non-twisted thread in the weaving became more popular with the time at that period.

• The Journal of Korean Academy of Prosthodontics
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• v.42 no.6
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• pp.628-640
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• 2004

Statement of problem. Wear as a result of repeated closing/opening cycles may decrease the friction coefficient of screw head, threads, and other mating components and, consequently, resistance to opening gradually decreases. It may cause screw loosening, which is one of the most common failures in implant prosthesis. Purpose. The purpose of this study is to evaluate the changes on the head and thread surface of the abutment screws after repeated closing and opening through the examination of tested screws in SEM(scanning electron microscope). Materials and methods. Five species of abutments were selected (3i-three, Avana-two) respectively by two pieces. The implant fixtures were perpendicularly mounted in liquid unsaturated polyesther(Epovia, Cray Valley Inc.) with dental surveyor. Each abutment was secured to the implant fixture by each abutment screw with recommended torque value using a digital torque controller. The abutment screws were repeatedly tightened and removed 20 times with a digital controller. FESEM (field emission scanning electron microscope, Netherland, Phillips co., model:XL 30 SFEG) was used to observe changes of each part caused by repeatedly closing/opening expeiment. First, the Photomicrographs of pre-test screws provided by each manufacturer were taken. The changes of each screw were investigated after every fifth closing and opening experiment with FESEM. Scaning electron microscope photomicrographs of each screw were taken four times. Results. As the number of closing and opening was increased, the wear or distortion of hexed or squared slot that contacted with the driver tip was more severely progressed. Wear or distortion of hexed slot was more severe than that of squared slot and it was more remarkable in the titanium screw than in the gold screw. All the tested screws showed that the width in the crest of their screw thread decreased gradually as the test was proceeded. Conclusions. Conclusively, we recommend the clinical use of gold screw, a periodic exchanges of abutment screws and avoiding repeated closing/opening unnecessarily. We also suggest a more careful manipulation of the abutment screw and screw-driver and using of abutment screw with an acute-angled slot design rather than an obtuse-angled one. Finally, it is suggested that the new slot design and the surface treatment for enduring wear or distortion should be devised.