• The Journal of Korean Academy of Prosthodontics
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• v.42 no.2
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• pp.210-225
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• 2004

Statement of problem: Implant screw loosening has been remained problem in restorative practices. Surface treatment of screw plays a role of preventing screw from loosening in implant screw mechanism. Purpose : The purpose of this study was to investigate surface characteristics of TiN and ZrN film ion plated screw with titanium and gold alloy screw and to evaluate wear resistance, surface roughness, and film adhesion on screw surface using various instruments. Material and methods : GoldTite screws and titanium screws provided by 3i (Implant Innovation, USA) and TorqTite screws or titanium screws by Steri-Oss (Nobel Biocare, USA) and gold screws and titanium screws by AVANA (Osstem Implant, korea) were selected. Ion plating which is much superior to other surface modification techniques was carried out for gold screws and titanium screws using Ti and Zr coating materials with nitrogen gas. Ion nitrided surface of each abutment screw was observed with field emission scanning electron microscopy (FE-SEM, micro-diamond scratch tester, vickers hardness tester, and surface roughness tester. Results : 1) The surface of gold screw and GoldTite is more smooth than ones of other kinds of non coated screw. 2) The ZrN and TiN coated surface is the more smooth than ones of other kinds of screw. 3) The hardness of TiN and ZrN coated surface showed higher than that of non coated surface. 4) The TiN coated titanium screw and ZrN coated gold screw have a good wear resistance and adhesion on the surface. 5) The surface of ZrN coated screw showed low surface roughness compared with the surface of TiN coated screw. Conclusion : It is considered that the TiN and ZrN coated screw which would prevent a screw from loosening can be applicable to implant system and confirmed that TiN and ZrN film act as lubricant on surface of screw due to decrease of friction for recycled tightening and loosening.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2013.05a
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• pp.132-132
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• 2013

본 연구는 R/F-PCB(Rigid/Flexible Printed circuit Board)의 Cu Pattern에 최종 표면처리 방법으로 사용되는 ENIG(Electroless Ni/Immersion Gold) 공정을 대체하여 ECIG(Electroless Co/Immersion Gold)공정을 적용하고자 하는 것으로 무전해 니켈 도금의 장점인 고경도, 내마모성, 납땜성, 내식성을 가지면서 니켈 도금의 취약점인 연성을 개선한 도금액을 개발하고자 하였다. 개발된 도금액을 이용하여 Cu Pattern에 도금할 경우 일반 무전해 니켈 도금에서 나타나는 불량 원인 중 하나인 Space 부분에 도금이 되는 현상이 현저히 감소하였으며, 연성 또한 향상됨을 관찰할 수 있었다.

• Journal of Sensor Science and Technology
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• v.15 no.5
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• pp.352-356
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• 2006

In this paper, we developed enzyme electrode of a new form to improve performance of disposable glucose sensor. We could fabricate electrode of Cu/Ni/Au structure which has very low electrical resistance (0.1 $\Omega$) by sticking copper film to plastic film with laminating method and electro-plated nickle and gold on it. The enzyme electrode was completed by immobilizing enzyme on the fabricated electrode. The fabricated glucose sensor has very quick sensing time as 3 seconds, and excellent reproducibility, fabrication yield as well.

• Applied Microscopy
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• v.46 no.3
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• pp.167-169
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• 2016

Solder/electroless nickel immersion gold (ENIG) joint sample which is comprised of dissimilar materials with different mechanical properties has limited the level of success in preparing thin samples for transmission electron microscopy (TEM). This short technical note reports the operation parameters for ultramicrotomy of solder joint sample and TEM analysis results. The solder joint sample was successfully sliced to 50~70 nm thick lamellae at slicing speed of 0.8~1.2 mm/s using a boat-type $45^{\circ}$ diamond knife. Ultramicrotomy can be applied as a routine sample preparation technique for TEM analysis of solder joints.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.675-678
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• 2000

Using the principle of the cross capacitor, a precise system for measuring the electric constants of liquids has been developed. The four electrodes of the cross capacitor were formed around fused-silica tube by plating a gold film. The effect of a non-uniform tube wall ok the measured permittivity was investigated As the individual characteristics of the tubes were determined to be constant, the pure dielectric constants extracted from any effect of the fused-silica material could be precisely derived with uncertainty of less than ${\pm}$ 0.02∼0.05 %.

• Proceedings of the Membrane Society of Korea Conference
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• 1994.10a
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• pp.8-11
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• 1994

Disposal of hazardous ions in the aqueous streams is a significant industrial waste problem.. Waste streams from electronics, electroplating, and photographic industries contain metal ions such as copper, nickel, zinc, chromium(IV), cadmium, aluminum, silver, and gold, amongst others in various aqueous solutions such as sulfates, chlorides, fluorocarbons, and cyanides. Typical plating solutions having similar compositions are listed in Table 1. Spent process streams in catalyst manufacturing facilities also contain precious metals such as Ag, Pt, and Pd. Developing an effective recovery process of these metal ions for reuse is important.

• Journal of architectural history
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• v.7 no.2 s.15
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• pp.29-48
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• 1998

The first Pagoda of Korea was introduced from China, and adapted from the wooden multi-storied pavilion. Also in Bronze one, multi-storied type of wooden pagoda was adapted. Bronze pagoda was used to buddhist ossuary and a kind of metalwork. Metalworks were made of gold, silver, copper, or iron by one of the methods of production-casting or hammering and decorated design of incision, raise, openwork, gold- plating or inlaying with gold and silver. Sometimes it was used as the easy carriage of Buddha image by guess. In most cases, the plan of Bronze pagoda was square and podium was one story. but in the advance of podium two-storied platform appeared. Column appeared in a symbol, so it didn't appear in a square and circular form. It means that the column was vertical member which only divided the wall. In koryo period, Gabled roof and Half-hipped roof was spreaded in public but Bronze pagoda was used to square Hipped roof. Vertical shaft over roof(上輪部), apart from body of pagoda(塔身部), was inserted on the hole above the Bokbal(覆鉢) for the balance of pagoda. And a thick iron bar put in the roof to the platform. It was sustained the balance of pagoda. The stories of pagoda were various from 3rd stories to 9, the lower stories was larger scale and the higher was smaller one.

• Journal of the Korea Furniture Society
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• v.23 no.4
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• pp.435-439
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• 2012

This research was performed to evaluate surface performance of gold plated carbonized board. After the carbonization at $850^{\circ}C$, volume, weight, and density decreased by 65.25%, 71.35% and 17.64%, respectively. Abrasion resistance and surface hardness of non-carbonized board exhibited the highest values of 0.093 g/100 revolution and 26.43 N/$mm^2$, respectively. Gold plated carbonized board showed intermediate values, 0.587 g/100 revolution of abrasion resistance and 24.35 N/$mm^2$ of surface hardness. Carbonized board showed the lowest values, 0.863 g of abrasion resistance and 21.50 N/$mm^2$, of surface hardness. These results were thought to reflect propertional relationship between abrasion resistance and surface hardness. Abrasion resistance and surface hardness of carbonized board appeared able to be improved by surface treatment such as plating.

• Conservation Science in Museum
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• v.16
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• pp.14-31
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• 2015

Sword with round pommel discovered in tomb No.39 in the Jisandong tumuli group (M310) is a large sword with a looped pommel enclosing a sculpted dragon head. The sword was produced using different techniques; gold decoration, plating, openwork carving and hammering by using gold and silver. This sword treated conservation work because it has deformation and damages of handle decoration, missing part of sword, and corrosion. Conservation treatment was that foreign material and corroded metal were removed from the surface, and performed to stabilize and reinforce the weakened metal. During the conservation treatment, the object was examined to understand its materials and production method. The result of research, the dragon head inside the looped, amalgam-plated pommel has surface gold decorations. The pommel has a thin gold plate placed over a bottom plate made of copper, which was hammered to create an embossed design. The silver plate-covered hilt, cylindrical in shape, has an openwork lattice design. The steel blade is single-edged. Finally, the locket of the sheath has an embossed design also created through hammering on a thin gold plate placed over the copper bottom plate.

• Korean Journal of Heritage: History & Science
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• v.52 no.1
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• pp.4-21
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• 2019

In this paper, 23 Silla gold earrings from the sixth and seventhand centuries, excavated from the Yeongnam region, were analyzed. Based on the silver content of the gold plate, they were classified into three types. The classifications included type I(20-50wt%), type II(10-20wt%) and type III (less than 10wt%). In the analysis process, the composition and morphological differences were identified on the surface of the gold plate. In the case of type I and II earrings, it was observed that the fine holes were concentrated in a relatively higher part of the gold content. The causes of the difference in the surface composition of the gold plate were divided into four categories: 1) surface treatment, 2) thermal diffusivity in the manufacturing process, 3) differences in composition of alluvial gold, and 4) the refining method of gold. It is possible that depletion gilding was attempted to increase the gold content while intentionally removing the other metals from the surface of the gold alloy in the portion where the gold deposit is relatively concentrated on the surface of the gold plating. The highest copper content was detected in the earring with the highest gold content of the analyzed earrings, and it was assumed that thermal diffusion had occurred between the gold plate and the metal rod during the manufacturing process rather than intentional addition. Copper was detected only in the thin ring earring type, and copper was not detected in the thick ring earring type or pendant type. It also proves that this earring has a high degree of tightness at higher temperatures, as there was an invisible edge finish on other earrings and horizontal wrinkles on the gold plate surface. In terms of the material of the gold plate, we examined whether the silver content of the gold plate was natural gold or added by alloy through analyzing the alluvial gold collected in the region. As a result of the analysis, it was found that on average about 13wt% of silver is included. This suggests that type II is natural gold, type III is refined gold, and type I seems to have been alloyed with natural gold. Here, we investigated the refining method introduced in the ancient literature, both at home and abroad, about the possibility of alloying silver after the refining process of type III earrings and then making pure gold. It was found that from ancient refining methods, silver which had been present in the natural gold was removed by reacting and combining with silver chloride or silver sulfide, and long-term efforts and techniques were required to obtain pure gold through this method. Therefore, it was concluded that the possibility of adding a small amount of silver in order to increase strength after making pure gold through a refining process is low.