• Restorative Dentistry and Endodontics
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• v.25 no.1
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• pp.133-143
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• 2000

목 적: 통상적인 근관성형 과정에서 근관형태의 직선화 경향을 발견할수 있으며 그 결과 만곡이 심한 근관에서 이상적인 근관 형태를 얻기가 어려움으로 인해 이를 극복하기 위한 많은 기구들과 근관 성형법들이 개선되었고 소개되었다. 본 연구에서는 수통형 Stainless Steel K-file, Niti 엔진 구동형 Profile .04와 Quantec LX file를 이용하여 만곡 근관의 성형 후 최종 근관 형태를 비교하고 평가하고자 한다. 방 법: 본 실험은 Bramante등의 방법을 변형하여 술 전의 근관 형태와 술 후의 근관 형태를 비교하였다. Schneider의 방법에 따라 $12^{\circ}$에서 $68^{\circ}$ 이내에 만독도를 가진 45개의 발거된 상하악 대구치의 근심근관들을 선택하여 15개씩 3개의 군으로 나누고 알루미늄으로 제작된 mold에 투명한 교정용 레진으로 매몰하였다. 근첨에서 2.5, 5, 8mm 지점에서 절단하고 각 mold에 재조립한 후 다음과 같이 근관 성형을 시행하였다. 제 1 군은 SS K-file를 이용하여 Step-back 방법; 제 2 군은 NiTi 엔진 구동형인 Profile .04 ; 제 3 군은 NiTi 엔진 구동형인 Quantec LX file로 근관 성형하였다. 술 전과 술 후에, 각 시편들을 입체 현미경으로 사진 촬영하여 근관 중심 위치 이동률, 근관성형 후 면적과 모양, 잔존 상아질의 최 소 두께를 Sigma scan / image software program으로 계산하고 One way ANOVA로 통계적 유의성을 검증하였다. 결 론: 1. Profile .04와 Quantec LX는 SS K-file보다 근관성형시 근관의 본 형태를 유지하는 경향이 있었으나 통계적으로 유의성이 없었다(p>0.05). 2. 근관 성형 후 면적은 Profile .04 엔진 구동형 NiTi file를 이용한 군이 다른 군과 비해 가장 적었으나 통계적으로 유의성이 없었다(p>0.05). 2. 모든 방법들은 같은 부위에서 같은 방향으로 전이되는 양상을 보였다. 즉, 근단부에서는 바깥쪽으로, 중앙부에서는 안쪽으로 전이하려는 경향이 있었다. 그러나, 치관부에는 그러한 법칙이 적용되지 않아 전이되는 양상이 안쪽이나 바깥쪽으로 구별되지 않게 일어났다. 3. 술 후에 근관의 모양은 원형, 타원형, 불균일한 형태들이 다양하게 나타났지만, Profile .04와 Quantec LX를 사용했을 때 주로 원형 형태의 근관을 보여주었으며 Stainless Steel K-file은 타원형이나 불균일한 근관 형태를 보였다.

• Journal of Conservation Science
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• v.25 no.4
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• pp.373-381
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• 2009

To preserve steel cultural properties on display outdoors, the surface of these relics is processed with a covering treatment, which is a typical anti-corrosion method. Since the registered cultural heritage of Korea No. 78 Locomotive at Jangdan Station of Gyeongui Line will be treated by preservation process and displayed in the open outdoor area, effective surface covering agents were selected through testing to prevent the corrosion of the locomotive. The mixed wax are based on two types of microcrystalline wax which is one of regular surface covering agents for locomotives and bee‘s wax. For the weather resistance test, 3 types of wax were applied to each specimen of the locomotive and the specimens were tested in the Xenon-Arc Accelerated Weathering Tester for 1000 hours in accordance with the ISO 4892-1981 criteria and the test results were compared. As a result, on the surface of the specimen coated with the bee's wax, a whitening event appears after 400 hours which causes aging, and the specimens coated by the microcrystalline wax showed signs of a whitening event after 800 hours. The moisture contact angle with the microcrystalline wax coating was also less than with the bee's wax. Therefore, it was found that the high temperature microcrystalline wax is the most effective coating agent in terms of weather resistance and moisture blocking capability and the high temperature microcrystalline wax was adopted for coating the surface of the locomotive.

• Conservation Science in Museum
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• v.16
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• pp.122-137
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• 2015

White porcelain pitcher with an openwork dragon and cloud design across its surface in the collection of the National Museum of Korea (Deoksu 5531) was acquired in 1915. The restoration has been so far completed only for the mouth of the pitcher. This study discusses a new method based on 3D scanning and printing for the restoration of missing parts in the openwork dragon and cloud design. A strength test was performed on six output materials that have been already commercialized for comparison with the strength of materials used for traditional restoration such as epoxy putty (Quick Wood^®) and epoxy (Araldite AY103+HY956^®). This process confirmed that the digital technology-aided making of a restoration model requires less time and efforts than handmade work, all the while producing a more precise model. More importantly, this method being a non-contact method, it reduces risks associated with handmade work. Another advantage of this method is that digital pre-restoration images can be saved and used for future references. Notwithstanding, future research is needed on how to effectively apply digital technology for restoration of ancient objects and how to evaluate and use 3D output as well as on the method of shaping, joining and coloring the 3D output.

• Journal of Conservation Science
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• v.24
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• pp.1-11
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• 2008

The Unhyungung Water Container in the possession of the Seoul Museum of History in Korea is consisted of a calcareous marble developed laminated bedding and numerous argillaceous veinlets. This monument should need to conservation treatment because of black discoloration and seriously numerous cracks. Vertical and horizontal cracks in the monument are developed following stratification and argillaceous veinlets that are relatively low coherence between the rock materials. We have proved that the material inducing discoloration on the surface is carbon which is formed by deposited organic matters. As the result of the ultrasonic measurements, although highly surface weathering degree, the physical properties of the Unhyungung Water Container is confirmed slightly weathered state. The depths of cracks in the monument are calculated at maximum 60mm in some cracks completely penetrating into the wall and at minimum 9mm in the other crack. The cracks, developed following veinlet, are revealed that there penetrate from an outer wall to an inside wall for the monument. And most depths of cracks, developed following stratification, are calculated 20 to 30mm. This result will offer a significant data for conservation of the Unhyungung Water Container.

• Korean Journal of Food Science and Technology
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• v.32 no.3
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• pp.640-645
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• 2000

The effect of gamma-irradiation on the quality changes of the grain shape improved Meju was studied. Meju was prepared, irradiated at 0, 5, 10 and 20 kGy, and then stored at $25^{\circ}C$ for six months. The results showed that the fungi and acid producing bacteria were completely eliminated by gamma-irradiation with dose of 10 kGy or higher and the Bacillus was decreased by 5 log cycles with dose of 10 kGy. The $D_{10}$ values of the fungi, Bacillus and acid producing bacteria were 0.79, 2.28 and 1.17 kGy, respectively. Also, the microorganisms that survived irradiation was decreased significantly with the duration of storage period. The $NH_3-nitrogen$, negative factors of quality of Meju, and browning were repressed and the protease activity and pH were not affected by gamma-irradiation. Therefore, it was considered that the Meju treated with gamma-irradiation maintained better quality than that of the control with storage.

• Journal of Conservation Science
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• v.32 no.4
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• pp.535-548
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• 2016

Hanging paintings are used for special ceremonies in Buddhist temple. They are stored in special storage box called "Gwaebulgwae" which means storage box for a hanging painting. Studies regarding pigments, background fibers and textiles of hanging paintings are carried out with many data in the field of conservation science. However, there are only few studies for the axes of hanging paintings and storage boxes. In this study, species identification for wooden axes of hanging paintings and storage boxes from the Joseon dynasty are carried out. Hanging painting of Beopjusa temple, Magoksa temple, Sudeoksa temple, Gaeamsa temple, Sudosa temple, Bukjangsa temple, Dorimsa temple, Tongdosa temple and Daeryeonsa temple are selected. Sampling is carried out from the axes of hanging paintings and storage boxes. 81 samples are collected from hanging paintings and storage boxes. As a result, 51 hard pines of Pinus spp., 8 Tilia spp., 6 Juniperus spp., 5 soft pines of Pinus spp., 4 Tsuga spp., 3 Pseudotsuga spp., 2 Berchemia spp., 1 Pyrus spp., 1 Bambusoideae are identified. Tsuga spp. and Pseudotsuga spp. might be used in conservation and restoration works in modern times because those species do not naturally grow in Korea. Most hanging paintings and storage boxes are made of hard pine. Also, some of are made of Tilia spp., because it represents the symbol of Buddha. Some unique kinds of trees used for wooden sculpture are identified, such as Juniperus spp. and Berchemia spp. Authentic conservation and restoration works could be carried out with this data-base.

• Food Science and Preservation
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• v.14 no.3
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• pp.239-246
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• 2007

The effects of gamma irradiation on the physiochemical and physical characteristics of apples were investigated during post-irradiation storage at $4^{\circ}C\;and\;25^{\circ}C$. The contents of total and reducing sugars were analyzed and the results indicated that apples receiving 1 kGy of gamma irradiation did not show significant differences in sugar contents compared to non-irradiated controls. Important physiological characteristics were evaluated by measurement of total phenolic content and total flavonoid content, reducing power, and radical scavenging ability, and the results indicated that gamma irradiation at a dose of 1 kGy did not affect physiological activities. Changes in physical parameters such as weight loss, strength, cohesiveness and hardness, during post-irradiation storage, were temperature-dependent, whether the apples were irradiated or not The color and sensory acceptance of the apples were not affected by irradiation during cold storage. However, minor deterioration in color quality and sensory acceptance of irradiated apples was noted under ambient temperature storage. We conclude that gamma irradiation(1 kGy) does not affect apple nutritional content stability, functional properties, or physical characteristics, especially upon cold storage after radiation treatment.

• Journal of Food Hygiene and Safety
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• v.31 no.4
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• pp.272-277
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• 2016

The purpose of this study was to investigate present status of use about antimicrobial agent (triclosan, ethanol) and preservatives (sodium benzoate, methyl p-hydroxybenzoate, propyl p-hydroxybenzoate) in dentifrice. 75 samples including 16 mouthwashes were analyzed in this study. Contents of triclosan and preservatives were analyzed using by HPLC and ethanol was analyzed by headspace-GC. Preservatives were detected from total 37 samples, which are suitable for the legal limits in Korea. Methyl p-hydroxybenzoate was detected from 26 samples (0.003~0.19%), propyl p-hydroxybenzoate was detected from 11 samples (0.002~0.02%) and sodium benzoate was detected from 14 samples (0.1~0.3%), respectively. Methyl p-hydroxybenzoate was detected from 6 samples (0.03~0.19%), propyl p-hydroxybenzoate was detected from 1 samples (0.01%) and sodium benzoate was detected form 5 samples (0.1~0.2%) in 20 dentifrice for children. Triclosan was not detected from 75 samples. Ethanol was detected from 16 samples (4.9~21.9%) in 19 samples; among them three samples showed the higher contents (20.5~21.9%) but ethanol contents was not labeled in these samples.

• Journal of Korean Society of Forest Science
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• v.98 no.1
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• pp.115-124
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• 2009

New strain needs to maintain desirable characteristics for long term when it was bred, but in lapse of time it degenerates into a bad condition. Therefore the influence of temperature on the viability and survival rates of Lentinula edodes strains were examined after cryopreservation. Also, liquid nitrogen preservation for L. edodes has been proved to be one of the most reliable method. However, a mechanical damage of strain is inevitable during cryopreservation of the fungus because the fungus is very sensitive to stress of cooling rate in the freezing process. So we tried to find out state change of L. edodes with a programmable freezer. L. edodes strains were preserved at $-20^{\circ}C$, $-80^{\circ}C$ and $-196^{\circ}C$ for 50 days. At $-20^{\circ}C$, its mycelial growth became extinct. When thawed, the growth of mycelia which were preserved at $-80^{\circ}C$ was fastest. Attempts were made to investigate viability of L. edodes strains after freezing at $-80^{\circ}C$ and $-196^{\circ}C$, respectively. As the result, more than 90% showed high survival rate of strains tested at $-80^{\circ}C$ and $-196^{\circ}C$. Mycelial growth between apical and basal parts of colony after freezing preservation for 50 days was compared. At apical and basal parts, the survival rates showed 100% at $-80^{\circ}C$, but 98% and 94% at $-196^{\circ}C$, respectively. We confirmed that the ice crystal formation temperatures of L. edodes strains were $-6.0^{\circ}C$ for Sanlim 1, $-5.5^{\circ}C$ for the Sanlim 2, $-4.0^{\circ}C$ for the Sanlim 3 and $-15.5^{\circ}C$ for the Sanzo 302. These results indicated that L. edodes strains showed completely different responses to the ice crystal formation. We knew the fact that even the same species, especially L. edodes, they displayed completely different responses to the same freezing condition. Also, this has nothing to do with the connection between temperature type and freezing point. And a protocol was tried to minimize state change of L. edodes strains using programmable freezer when they are frozen, but it was not effective on them.

• Economic and Environmental Geology
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• v.56 no.1
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• pp.103-114
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• 2023

The Christian Museum of Gongju Jeil Church was first built in 1931 and was largely damaged during the Korean War, but the walls and chimneys have been preserved. This building has a high architectural values in that the chapel was reconstructed in 1956, and maintains its original form through repair of damaged parts rather than new construction. The stained glass windows were as installed in 1979 and has a great significance in the Dalle de Verre method using lump glass. However, some of the stained glass damaged partially, such as various cracks and splits, and vertical and horizontal cracks in the joint fillers of supporting the colored glass. As the structural materials of the stained glass window, an iron frame and cement mortar filled with it were used, and corrosion of iron, cracking of mortar and granular decomposition appear partially due to weathering. In the joint fillers, the content of Ca and S is very high, indicating that gypsum were used as admixtures, and the gypsums grow in a rhombohedral and forms a bundle, which is investigated to have undergone recrystallization. As a result of modeling the ultrasonic velocity at the joint fillers, the left and right windows at the entrance show relatively weak in the range of 800 to 1,600m/s, and the lower right corner of the altar window and the upper left corner of the center window were also 1,000 to 1,800m/s, showing relatively low physical properties. And gypsums produced during the neutralization of lime mortar were detected in the joint fillers and contaminants on the surface. Such salts may cause damage to the joint material due to freezing and thawing, so appropriate preventive conservation is required. Also, since various damage types are complexly appearing in stained glass window and joint filler, customized conservation treatment should be reviewed through clinical tests.