• Restorative Dentistry and Endodontics
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• 제18권1호
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• pp.187-196
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• 1993

The purpose of this study was to evaluate the microleakage of retrofilled teeth with various materials [non-zinc Amalgam, IRM, Ketac-silver, CGP(cold-burnished, ultrafil)[and instruments for cavity preparation. Root apex were resected 2mm from apex horizontally and class I cavities were prepared in 2mm denpth, 1.5mm width and were filled with above mentioned materials. Root apex were resected 2mm from apex horizontally and class I cavities were prepared in 2mm depth, 1. 5mm width and were filled with above mentioned materials. 2% methylene blue dye solution was used for 4 days immersion and the linear leakage was measured with calipers and the volumetric leakage was determined with a spectrophotometer. The results were as follows : 1. Amalgam group showed the greatest amount of leakage and Ketac-silver group showed the least value. 2. By linear leakage test, the group retrofilled with Ketac-silver, or CGP showed better seal than the group of Amalgam or IRM. This was shown in both retrograde tip and Conventional method. 3. By volumetric leakage test, the group retrofilled with Ketac-silver showed significantly better seal than the group with IRM in retrograde tip method. 4. By volumetric leakage test, the group retrofilled with Ketac-silver showed significantly better seal than the group with Amalgam in the Conventional method.

• Animal Systematics, Evolution and Diversity
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• 제37권4호
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• pp.280-286
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• 2021

During a field survey on Korean coastal marine waters, two ciliates belonging to the genera Pseudovorticella Foissner & Schiffmann, 1975 and Frontonia Ehrenberg, 1838 in the class Oligohymenophorea de Puytorac et al., 1974, were collected. Even though the two genera are very common in the aquatic ecosystems, they had been superficially studied in Korean habitats. Using the observation of living cells and specimens impregnated by protargol, silver carbonate, and silver nitrate, two newly recorded ciliate are identified as P. paramarina Sun, Ji, Warren & Song, 2009 and F. ocularis Bullington, 1939. A brief diagnosis, remark, and comprehensive micrographs are provided for each species.

• Bulletin of the Korean Chemical Society
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• 제32권9호
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• pp.3433-3436
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• 2011

Some of metal nanoparticles have the potential for use as colorimetric assays for estimating solution properties, such as pH and temperature due to localized surface plasmon (LSP) phenomena. This report describes the use of silver nanoparticles (AgNP) conjugated with cytochrome c (Cyt c) for the colorimetric determination of solution pHs. When the pH of a solution decreases, the Cyt c immobilized on the AgNP undergoes a conformational change, leading to a decrease in the interparticle distance between Cyt c-AgNP probes and consequent red-shift in LSP. As a result, the color of the Cyt c-AgNP probe solution changes from yellow to red and finally to a grayish blue in the pH range from 11 to 3. This gradual color change can be used to determine the pH of a solution over a wide pH range, compared to other colorimetric methods that use gold nanoparticles.

• 대한자원환경지질학회:학술대회논문집
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• 대한자원환경지질학회 2003년도 춘계 학술발표회 논문집
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• pp.180-183
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• 2003

Epithermal deposits are an important class of hydrothermal deposits, that have recently seen an surge of exploration and research, principally as significant resources of gold and silver. Epithermal deposits form at shallow depths (surface to 1-2km) and temperatures less than 30$0^{\circ}C$ (Hayba et al., 1985), and encompass a variety of low-sulfidation (near-neutral pH, reduced fluid; LS) and high-sulfidation (acidic and oxidized fluid; HS) deposits (Sillitoe, 1993; White and Hedenquist, 1995). (omitted)

• Restorative Dentistry and Endodontics
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• 제14권2호
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• pp.31-37
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• 1989

The purpose of these study was to compare the sealing ability of a injection-molded thermoplasticized gutta-percha and silver amalgam as retroseal material in vitro. Sixty two upper and lower extracted human teeth with single root were randomly selected and instrumented in a conventional method with H-file. After instrumentation the root canal was obturated with gutta-percha by lateral condensation technique with AH26 and an apicoectomy was performed by beveling the root tip 45 angle. In the experimental group 1 and 2, a class I preparation was made and filled with silver amalgam or gutta-percha and in the experimental group 3 an apicoectomy only was performed. All specimens were immersed in black Indian ink, decalcified and cleared. The depth of dye penetration into the canals were evaluated by califer. The results were as follows ; 1. The experimental group 1 displayed the smallest mean dye penetration as 0.45mm. 2. The experimental group 3 displayed the greatest mean dye penetration as 0.65mm. 3. There was the difference in dye penetration between each group, but the difference was not statistically significant(P>0.05).

• 한국수산과학회지
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• 제23권6호
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• pp.443-450
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• 1990

The virtual population analysis technique was applied to the silver croaker, Otolithes argenteus, stock based on length frequency composition, age-length key and nominal catches taken by the trawl fleet and fixed-stake nets in the Kuwait's waters during $1981\~1988$. One-year-old fish was dominant, whereas three-year-old and older fish were at a very low level. Fishing mortality was much higher in the age groups of 2 and 3 than in the others. A strong year-class occurred in 1980 and 1981. Population size of fishable stock markedly decreased from 1982 to 1985 and remained at a low level during $1986\~1987$. The effects of changes in fishing effort showed that an increase in fishing effort would not lead to benefits in yield and would comprise more young and fewer old fish, whereas a reduction in fishing effort to a certain level (by $20\~40\%$ ) from the fishing effort level on the average during $1981\~1988$ could bring some small advantage to the fishery consisting of fewer young and older fish.

• 대한치과의사협회지
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• 제11권3호
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• pp.185-189
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• 1973

Dental amalgam in the clinic practice of dentistry is one of the most important materials. Mercury, one of the component of this alloy, is emitted in the form of vapor after filling as long as 5 days Silver particles penetrate into the dentine deeply along the tubles underneath cavity floor. To determine the permeability of mercury in the teeth following experiments were performed. Class 5 cavities total 40 from 10 dogs were prepared on upper and lower canines and amalgam alloys which contain about 10uCi of radioactive mercury were inserted. The animals were sacrificed 7 days after the experiments and the teeth were decalcified, sectioned and autoradiographed by means of emulsion and stained by H & E. Following are the results obtained from this experiments. 1. Blackened silver grains were found along the dentinal tubules underneath the cavity floor. Beyond the border of dentine and pulp chamber grains were seen in odontoblastic layer (Fig. 1, 2, 3, 4) 2. Underneath the odontoblastic layer, the pulp tissue showed almost normal appearance except slight dilatation of blood vessel.

• 복식문화연구
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• 제7권3호
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• pp.1-16
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• 1999

This study in concerned with the costume accessories appeared in Sam Kuk Sa ki. The accessories of both sexes were analized. Results of this research can be summarized as follows : It was appeared that names of accessories of men were fewer in number than those of women. Men\`s accessories such as a hat, bok-du, a belt,boots, shoes, and sock were mentioned in Sam Kuk Sa Ki. Women\`s accessories appeared such as a hat, a comb, a hair pin, a belt, shoes, and sock. A bok-du, boots, and a hared belt were used exclusively by men, while a hat, kwan(冠), a comb, a hair pin, a scarf, pyo( ) were worn exclusively by women. All men from different classes including true bone class as well as the common class wore bok-du, a hat, a hard belt, boots, sock ; however, class distinctions were made from materials used for those items. Also women\`s accessories were used as means of differentiating social status of the wearer by means of materials employed for each item. Especially, woman\`s hat and scarf were a symbol of the noble class. Only two classes of women from the true-bone class and women from the sixth du-pum class entited to wear hats. Wearing a scarf was not allowed to women from the common class. Class dirrernetiations were made by the materials used for hats and scarves. Materials for a scarf such as gold and silver leaf, pecock tail, and king fisher fly feather were restricted to women from true-bone class. Such as man\`s hat bok-du( 頭), use of women\`s comb and hair pin, scarf, leggings were items drived from Tang China. It clearly showed that costume accessories of Silla were heavily influenced by the Chinese. At the same time the costume accessories were sued to make sex difference among the people of Silla. Woman wore a soft belt made of cloth while man wore a hard belt. Woman\`s hat, a scarf, a comb, a hair pin, a belt or sash for a shirt, and leggings were woman\`s sex symbol. Thus, costume accessories of Silla appeared in Sam Kum Sa Ki functioned as means of differentiating social status of the wearer such as sex,class and rank in the society. Also, they showed that Silla kingdom had close cultural relationship with Tang China.

• 복식
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• 제26권
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• pp.163-173
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• 1995

The purpose of this study is to investigate the Ku which was worn by nomadic tribes which was Khitai, Mongols and Manchus. The results of this study can be summarized as follows. 1. The fur clothes were very important clothes that nomadic tribes put on in order to protect them against the cold. The Ku was an outfit for protection against the cold. It was made of ani-mal fur and its style was tight sleeve and long dress. 2. The Ku was worn in all social classes including emperor, nobles and the masses in ancient China and Asia dynasty. After the nomadic tribes estabilished dynasty in China the style of Ku was changed. All kinds of animal fur was used to make the Ku but the volume of fur, kinds and colors were classified severely by their social position. In Khitai dynasty the Ku was worn in same style. But the emperor wore the Ku of silver marten. The noble class wore the Ku of purple, black and blue marten and silver squirrel skin. The masses wore the Ku of the other colors marten, sheep, squirrel and dessert fox skin. In Mongol dynasty, the emperor wore the Ku of purple marten, silver squirrel, silver fox and black fox skin. The nobles wore the Ku of the other colors marten and squirrel. The masses wore the Ku of degraded animal fur. Before the Manchus estabilished the varient races dynasty in China, the rich man preferred the Ku of marten, squirrel, fox, goat furs. But the poorman preferred the Ku of cow, horses, pig, sheep, cat, dog, snake and deer skin. After the manchus conquered the China, the manners of dress were changed. Generally the fur did not appear in right side of garment, but high quality or noble fur appeared outside. Sometimes the inside or outside of Ku was made of silk fabrics and sleeves, neck-band was made of the high quality fur.

• Restorative Dentistry and Endodontics
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• 제5권1호
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• pp.41-46
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• 1979

Silver amalgam has superior mechanical and physical properties, therefore it has been widely used in dental clinics. But we have found the silver amalgam failures frequently, its important reasons are fracture, fallen-out, tarnish, corosion and secondary caries etc. The author studied the compressive strength of silver amalgam. The author made the standardized specimen, prepared the Black's Class II cavity on chromecobalt alloy, and placed the three types of Unitek$^{(R)}$ pin (Type of pins are straight type, "ㄱ" bent type, "$\sqcap$" bent type pin. The compressive strength was measured by (Dynamic Strain Meter Shinko Co. Japan). The author took the following results by comparing with the control group, not used pin. 1) Compressive force of silver amalgam in straight type pin was $187.11{\pm}39.00kg$, $252.98{\pm}31.91kg$ in "ㄱ" type bent pin, $189.00{\pm}37.46Kg$ in "$\sqcap$" type bent pin, $172.33{\pm}28.07Kg$ in the control group. 2) The statistic significance of the compressive strnegth between each group showed that "ㄱ" type, bent pin is stronger than the control group or straight type pin. 3) There were no difference of significances between the control group and straight type pin, control group and "ㄱ" type bent pin and "$\sqap$" type bent pin, "ㄱ" type' bent pin "$\sqcap$" and type bent pin.