• 한국표면공학회지
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• 제38권5호
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• pp.198-201
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• 2005

Nickel amalgam was Prepared by the electro-deposition with mercury cathode in a modified Watts bath. Homogeneous nickel amalgam was obtained. The fluidity of the amalgam decreased gradually with increased nickel quantity and become solid finally. Nickel powders of sub-micron size were obtained by a distillation of mercury from the amalgam. The characterization of the nickel amalgam was studied by SEM and x-ray diffractometry.

• Restorative Dentistry and Endodontics
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• 제16권1호
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• pp.158-166
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• 1991

In order to investigate the cytotoxicity of composite resin in vitro, BALB / C mouse fibroblast were cultured in MEM in which silux, P-50, microrest, clearfil, amalgam and glass - ionomer, in shape of $2{\times}9mm$ circular disk. The experiments were- performed by cell count on 4 hours, 1, 3, 6 days and the composite resin groups, amalgam, glass - ionomer were compared. 1. On the sixth day, the cellular number of resin composite groups were remarkedly reduced, in contrast, the that of amalgam and glass - ionomer group continuously increased. 2. It was only on the 4 hours that the cellular number contained in amalgam were reduced, but increased thereafter, and the cellular number contained in glass - ionomer are greater than other groups. 3. In resin group, especially between self - curing resin and light - curing resin, there is no difference in cellular number statistically (p>0.05). 4. It was amalgam where the round cell without cellular process was found on the 4. hours and on the 6 th day the cell without cellular process was found numeroulsy in resin group whereas in amalgam and glass - ionomer, like control group was contained cell forming monolayer. These result suggested that the toxicity of the self - curing and light - curing resin greater than that of the amalgam and glass - ionomer.

• Bulletin of the Korean Chemical Society
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• 제28권3호
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• pp.439-442
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• 2007

A solid state Hg(Au)/HgO reference electrode was prepared utilizing gold amalgam solid particles. Solid fine powder of the gold amalgam was prepared by chemical reduction of Au(III) with NaBH4 followed by reduction of Hg(II) in the presence of gold fine particles. The solid content in the suspension of the gold amalgam particles and fine mercury oxide particles in DMF containing PVC was precipitated by the addition of a large amount of water to give solid Hg(Au)/HgO/PVC mixture. After drying, the mixture was pressure-molded to a physically stable Hg(Au)/HgO composite reference electrode material. The electrochemical characteristics of the electrode as a reference electrode were very similar to an ordinary Hg/HgO reference electrode. The electrode material can be molded and fabricated in any desired shape and size. The surface can be renewed by a simple polishing process whenever contaminated or deactivated. The applicability of the electrode in the electrochemical detection of carbohydrates after anion exchange separation was evaluated.

• 보존과학연구
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• 통권14호
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• pp.45-76
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• 1993

Au-Cu alloyed coating layer were found by Hg-amalgam process and it seemed to be used Cu-amalgam process similar to Au-amalgam. Coated layer is dense and unique, Thickness of layer was 1.5 to $18.0\mum$ which had 95.3 to 99.8% purity of gold Matrix metal mostly cosists of forged copper alloy which had high purity and ferrite ($\alpha$) strusture. It showed excellent refining technical level at that time. Aowever, the nail, ferrous matrix used for strength needed, composed of silver foil packed and gold layer for adherence between ferrous matrix and gold layer

• 한국표면공학회지
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• 제8권1호
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• pp.1-9
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• 1975

The crorosion film of gilt bronz, silver and iron objects, which were excaved from Ancient Tomb of Silla Dynasty, was removed by the electrolytic reduction process. These metallic objects were mainly investigated for microstructure, designs and gilting film etc. Most iron objects might be made by hot forging process. The cold extrusion technique might be used for gold and silver objects, in addition to an amalgam method might be applied for the gilting Au film on Cu-alloy surface. For the gilting on glass surface, first, a Cu alloy was cladded on glass , next, Au-film was obtained on the Cu-ally by the amagum method.

• Journal of Oral Medicine and Pain
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• 제23권2호
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• pp.193-209
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• 1998

In identifying bodies that are severely decayed or damaged, methods using fingerprints and various biochemical tests are known to have its limits. To overcome this, forensic odontological method which is based on the analysis of the cranium, tooth and dental restoration is used to enhance the accuracey of individual identification. For this reason, I have come to analysis of the dental materials that exists between the teeth that is perceived to have been previously restored and the one adjacent to it. By analyzing the constituents of gold crown-restored, non-precious metal-restored, gold inlay-restored and amalgam -restored teeth, and adjacent teeth using EDX(energy dispersive X-ray microanalysis) which was invented to analyze very small amount of elements, the nature of the restoration could be predicted and the results obtained were as follows. 1. Some of constitute of gold alloy was extracted from residual cement of gold crown restoration, but that was not extracted from the restored tooth and the one adjacent to it. 2. Some of constituents of non-precious metal alloy was extracted both in the residual cement on the tooth with no-precious metal restoration and in the tooth with the restoration itself. However, none of its constituents were found in the tooth adjacent to it. 3. Some of constituents of gold alloy were found in the residual cement of gold inlay, but they were not found in the restored tooth and the adjacent tooth. 4. Some of constituents of amalgam alloy were found both in tooth restored with amalgam and in the adjacent tooth. From the results obtained above, it is possible to utilize the data obtained from analyizing residual dental materials in a more effective way. This data compensates for the lost data due to any harm done to the restorations prior to individual identification and further enhances the accuracy. Therefore, it could be concluded that this process of analyzing residual dental materials could be beneficial to individual identification in the area of forensic odontoldogy.

• 보존과학회지
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• 제28권1호
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• pp.29-37
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• 2012

이 연구는 매장상태에서 출토되는 금동유물의 표면색이 고유한 금색 이외에 붉은 계열의 색들과 교반되어 나타나는 원인을 규명하고자 수은아말감도금법을 재현해 보고 완성품에 대하여 열처리 조건을 변화시켜 도금층의 표면색과 표면 및 단면의 상태변화를 알아보고자 하였다. 그 결과 높은 열처리 실험조건 일수록 도금층에 검은 산화물층이 넓게 생성되었으며, 산화물층을 제거한 부분에서는 붉은색의 도금 표면색이 표출되었다. 또한 표면이 노란색과 붉은색으로 교반된 시료의 미세 표면관찰에서는 색상에 따라 표면상태의 변화양상이 다르게 나타났으며 단면에서는 도금층 공극의 밀도와 크기가 점차 커지는 것으로 밝혀졌다. 열처리 실험 후 표면성분분석 결과 온도가 올라갈수록 Hg와 Au의 비율은 감소하였으나 Cu의 성분비는 증가하였다. 또한 단면분석 결과에서도 실험조건에 따른 층위별 Au와 Cu의 성분변화가 반비례하는 경향을 보였다. 이러한 실험결과들을 볼 때 아말감을 이용한 금동유물은 생산과정이나 생산 이후에 열이 도금층의 표면색에 영향을 미치는 것을 의미하며 도금층 상태에도 관계된다는 것을 확인할 수 있었다.

• Restorative Dentistry and Endodontics
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• 제27권1호
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• pp.24-33
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• 2002

Leakage studies have been performed frequently, since a fluid-tight seal provided by various dental fill-ing materials has been considered clinically important. The leakage of the various root-end filling materials has been widely investigated mostly dye penetration method. These dye studies cannot offer any information about the quality of the seal of a test material over a long period of time The purpose of this study was to evaluate the microleakage of root end cavities in blood contamination filed amalgam, intermediate restorative material(IRM), light cured glass ionomer cement(GI) and mineral trioxide aggregate(MTA) by means of a modified fluid transport model. Fifty standard human root sections, each 5mm high and with a central pulp lumen of 3mm in diameter, were and filled with our commonly used or potential root end fill ing materials after they were contaminated with blood. At 24h. 72h, 1, 2, 4, 8, and 12 weeks after filling, leakage along these filling materials was determined under a low pressure of 10KPa(0.1atm) using a fluid transport model. The results were as follows : 1 MTA group showed a tendency of decreasing percent of gross leakage (20m1/day) in process of time, whereas the other materials showed a tendency of increasing in the process time. 2. At the all time interval, GI group leaked significantly less than amalgam group and IRM group (p＜0.05). 3. At the 4 weeks, the percentage of gross leakage in MTA group decreased to 0% thereafter, the low per-centage of gross leakage was maintained in MTA group until the end of the experiment, whereas the percentage in IRM group increased to 100% 4. At the 12 weeks, percentage of gross leakage was significantly low in MTA group(0%), comparison with GI group(40%), amalgam group(90%) and IRM group(100%), but there was no significant difference between latter two materials.

• 한국재료학회지
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• 제30권9호
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• pp.453-457
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• 2020

Tomb No. 1 (Donghachong) of the Buyeo Neungsan-ri Tomb complex (listed as UNESCO World Heritage Site), is a royal tomb of the Baekje Sabi Period. One wooden coffin unearthed there is an important relic of the funerary culture of the Baekje. This study examines the production techniques of gilt-bronze objects attached to the wooden coffin excavated from Donghachong. The base metal of the gilt-bronze object is pure copper, with single α phase crystals in a heterogeneous form containing annealing twins; Au and Hg are detected in the gilt layer. We suggest that the surface of the forging copperplate is gilded using a mercury amalgam technique; it is thought that the annealing twins of the base material formed during the heat treatment process for the sheet metal. The gilt layer is three to five times thicker for the gilt-bronze objects found near the foot of the coffin than those near the head. We estimate the plating process is carried out at least three times because three layers are identified on the plate near the head. Therefore, it is likely that the materials and methods used to construct the gilt-bronze objects found in different parts of the coffin are the same, but the number of platings is different. This research confirms the metal crafting techniques used in Baekje by the examination of production techniques of these gilt-bronze objects. Further, our paper presents an important example of restoration and reconstruction for a museum exhibition, through effective use of scientific analysis and investigation.

• 한국조경학회지
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• 제32권1호
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• pp.69-79
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• 2004

This Paper examines theoretical terrains and design strategies of landscape urbanism which is an emerging hybrid field at the intersection of architecture, landscape architecture, and urbanism. Landscape urbanism offers alternative approaches for theory, education, and practice in contemporary landscape architecture. It views the emergent urban complex sites-post-industrial sites, landfill, brownfield, urban void, etc., not as a weakness, but as a strength. Landscape urbanism poses an understanding of landscape as an element of urban infrastructure. In this sense, the landscape is seen in the context of contemporary urban development and public works. As a complex amalgam, landscape urbanism is more than a design style it is an ethos, an attitude, a way of thinking and acting. We can chart the main characteristics of landscape urbanism such as horizontality and surface, infrastructure, process, technique, and ecology. Multilayered examples of landscape urbanism can be seen in several experimental practices such as worts of Rem Koolhaas, MVRDV, Adriaan Geuze/West 8, James Comer, etc. It is possible to summarize the productive strategies for landscape urbanism as follows : thickening, folding, new materials, nonprogrammed use, impermanence, and movement.