• Conservation Science in Museum
• /
• v.17
• /
• pp.101-116
• /
• 2016

Ceramic cultural artifacts restored with gypsum-based materials are prone to decay over time due to gypsum's natural absorption and release of atmospheric moisture, often leading to distortion and peeling of painted layers. This study proposes a new restoration material which utilizes extra hard stone, significantly superior in strength to regular gypsum. In order to enhance its physical properties and make it suitable for restoration of ceramics, extra hard stone is mixed with metakaolin. This mixture far surpasses regular gypsum in compressive strength(119MPa vs. 26MPa) while also maintaining a much lower wear rate(0.88% vs. 2.53%). Furthermore, the water absorption rate(2.9%) of the mixed material is over five times lower than that of regular gypsum(17.2%). When examined using a SEM(Scanning Electron Microscope), this mixture also proved superior to extra hard stone in terms of hardened density. The addition of metakaolin increases the mixture's strength and water resistance over that of extra hard stone and also improves its surface density, making it ideal for the restoration of ceramics. It has already been used to repair ceramic objects in the Museum's collection: Clay basin(sinan 18892), Buncheong ware bottle with incised peony design(jubsu 2034), Buncheong ware bowl with chrysanthemum(jubsu 1730). Results thus far have shown the mixture to be easy to inject and layer as well as harden into an even surface, which allows for smooth application of paint for color matching.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
• /
• 2000.04a
• /
• pp.6-7
• /
• 2000

개발도상국의 급격한 인구 증가에 의해 세계 60억 이라는 인구도 2050년을 맞아 약 100억에 도달할 것이라고 일컬어진다. 이로 인한 장래의 식량 위기에 대비하여 벼, 밀, 옥수수 등의 증산, 품종 개발도 물론 필요하지만 선진국을 중심으로 시장성 높은 작물의 소비가 우선되어지는 상황에 맞추어 세계적으로 주식이 될 수 있는 새로운 곡류의 확보와 생산체제도 중요한 문제이다. 한편으로 생활의 향상에 따른 식물의 다양화와 건강지향의 관점으로 본 다 품목 소량형의 식생활을 하는 것이 식물성 allergy의 방지 측면으로서의 곡류 특히 잡곡류의 유효 이용이 부각되어진다. 이들 중 amarans, quinoa는 벼과 식물에 비교해서 광합성능이 좋은 C4식물로서 생장이 빠르고 동시에 비타민, 무기질, 지질이 풍부하고 구성 단백질 중에 필수 아미노산을 많이 함유하여 아미노산 등급도 높고 특히 영양 발란스도 우수하다. 또 cholesterol 저하작용, 식물섬유에 의한 대장암의 억제 작용 등이 잘 알려져 있다. 그리l고 quinoa에 대해서는 아메리카 항공우주국(NASA)에서 CELSS(Controlled Ecological Life Support System; 장기간 우주특무비행의 승선원을 위한 공기중의 이산화탄소를 제거하고 식량·산소·물을 만들어 내기 위해 식물을 이용하는 방법)에 적합한 작물 후보로써 선택되어 신규 식품소재로써 주목받고 있다. 이상과 같은 견지로부터 amarans, quinoa를 일상식화되고 있는 빵에 이용하기 위해 제빵성 및 혼합중의 반죽의 모든 성질에 대해서 검토했다. amarans는 초과의 Amaranthus에 속하고 주요 생산국은 아메리카, 멕시코, 페루등이지만 일본에서는 주로 A.hypochondriacus가 수입되어 이용 되어지고 있다.amarans의 가루는 단독으로는 점탄성 있는 반죽을 형성하지 않기 때문에 밀가루에 일부를 대용한 wheat flour dough를 사용하고 가정용 제빵기로 구워 최종 단계에까지의 제빵성 결과를 산출했다. amarans folur 5%의 대체에는 빵의 비용적이 비교적 증대했지만 그 이상 amarans flour을 대처하면 확연히 비용적은 감소했다. amarans flour 10% 대체에 hemicellulase 1250U 이상을 첨가하면 비용적은 눈에 띄게 증대했다. farinograph에 있어서 반죽의 안정성은 amarans flour 10% 대용에 현저히 감소했다. 반죽의 점탄성(아축응력, 탄성률, 점성계수)는 amarans flour 10%를 대용한 것이 무첨가한 것보다 많이 단단해졌음을 알 수 있었다. 혼합중의 반죽의 조사형 전자현미경 관찰로 amarans flour로 대체한 gluten이 단단해졌음을 알수 있었다. 유화제 stearly 칼슘, 혹은 hemicellulase를 amarans 10% 대체한 밀가루에 첨가하면 확연히 비용적을 증대시킬 수 있다는 사실을 알 수 있었다. quinoa는 명아주과 Chenopodium에 속하고 페루, 볼리비아 등의 고산지에서 재배 되어지는 것을 시료로 사용하였다. quinoa 분말은 중량의 5-20%을 quinoa를 대체하고 더욱이 분말중량에 대하여 0-200ppm의 lipase를 lipid(밀가루의 2-3배)에 대하여 품질개량제로서 이용했다. 그 결과 quinoa 대량 7.5%에서 비용적, gas cell이 가장 긍정적 결과를 산출했고 반죽의 조직구조가 강화되었다. 또 quinoa 대체에 의해 전분-지질 복합제의 흡열량이 증대된 것으로부터 전분-지질복합제의 형성 촉진이 시사되었다.이것으로 인하여 호화억제에 의한 노화 방지효과가 기대되었지만 실제로 빵의 노화는 현저히 진행되었다. 이것은 quinua 대체량 증가에 따른 반죽의 안정성이 저하되어 버린 것으로 생각되어진다. 더욱이 lipase를 첨가하면 반죽이 분화하는 경향이 보여졌지만 첨가량 75ppm에 있어서 상당히 비용적의 증대가 보였다. 이것은 lipase의 가수분해에 의해 생긴 monogliceride에 의한 유화각 일어나서 보존성이 개선되어진 것으로 quinoa를 보다 많이 빨에 이용하기 위해서는 lipaserk 품질개량제로서 유효하다는 것을 알 수 있었다. 또 lipase는 quinoa의 대체량이 비교적 많은 10-20%의 섭취가 곧 allergy 질환 문제의 개선책이 되는 것은 물론 amarans, quinoa에는 lysine, 함황아미노산이 많고 지질중의 지방산조성도 좋고 무기질도 많이 함유되어 있다. 이와같이 우리들 개인의 건강에 대한 배려도 있고 amarans, quinoa등의 식품재료를 적극적으로 사용할 수 있도록 유념해 두었으면 하는 바램이다.

• Proceedings of the KSAR Conference
• /
• 2001.03a
• /
• pp.77-77
• /
• 2001

본 연구는 돼지 동결정액의 번식성적을 개선코자 기존의 maxi-straw와 cryogenic-vial을 이용하여 포장방법에 따른 동결방법과 융해방법별 정액성상 및 번식성적을 비교하였다. 동결방법은 두 가지 포장방법 모두 정액의 양(5$m\ell$)과 농도(5.0$\times$$10^{9}$/dose)가 동일한 조건으로 처리하였으며, LYE(Lactose egg york extender) 보존액으로 희석하여 액체질소 상단 15cm에서 20분간 동결하였다. 융해방법은 maxi-straw는 52$^{\circ}C$에서 45초간 cryogenic-vial은 52$^{\circ}C$에서 190초간 융해하여 $25^{\circ}C$로 가온 된 80$m\ell$ BTS (Beltsville thawing solution) 보존액과 혼합하였다. 정액성상검사는 정자자동분석기(SAIS : Sperm Analysis Image System, Korea)를 이용하였다. 총활력(TM : Total motility)과 정자의 빠르기(VCL : Curve linear velocity)는 maxi-straw가 54.3%와 46.6%로 cryogenic-vial의 35.6%와 36.6%보다 우수하였다(P<0.05). 정자의 직진성(STR : Straightness)과 NAR은 maxi-straw가 53.2%와 32.6%로 cryogenic-vial의 47.3%와 29.8%와 비슷한 경향을 나타내었다. 수태율과 분만율 및 총산자수는 maxi-straw가 77.3%, 68.2% 및 8.0두로 조사되어 cryogenic-vial포장방법의 66.7%, 61.9% 및 7.4두보다 다소 우수하였으나 통계적인 유의차는 인정되지 않았다. 이상의 결과로 볼 때 cryogenic-vial방법이 새로운 돼지 동결정액 포장방법의 가능성을 나타낸다고 사료된다.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.27 no.5
• /
• pp.864-868
• /
• 1998

The studies were carried out to investigate the mixed effects of medicinal herbs, such as Lithospermum erythrorhizon and Glycyrrhiza uralensis(LG), and LG with chitosan(LGC) on shelf-life of kimchi fermented at 1$0^{\circ}C$ for 25 days. During the fermentation, pH was more slowly lowered in LG(1%, 3%) and LGC treatments than in control. Titratable acidity of these treatments was slightly lower than that of control. Viable cells of total bacteria and lactic acid bacteria in kimchi added with LG(3%) and LGC showed inhibitory effects about 1.2~1.6, 1.3~1.8 log10 cycle. The sour taste of kimchi added with LG or LGC was changed more slowly than that of control during fermentation for 5 days at 1$0^{\circ}C$. But flavor, color and overall acceptability did not show significant differences(p<0.05) among treatments. The color of kimchi added with LG was improved significantly by adding of 1% chitosan. The shelf-life of kimchi added with LGC was extended about 10 days than control.

• Proceedings of the KACD Conference
• /
• 2008.05a
• /
• pp.184-197
• /
• 2008

This study was to investigate the influence of combining composite resins with different elastic modulus, and occlusal loading condition on the stress distribution of restored notch-shaped non-carious cervical lesion using 3D finite element (FE) analysis. The extracted maxillary second premolar was scanned serially with Micro-CT. The 3D images were processed by 3D-DOCTOR. ANSYS was used to mesh and analyze 3D FE model. A notch-shaped cavity was modeled and filled with hybrid, flowable resin or a combination of both. After restoration, a static load of 500N was applied in a point-load condition at buccal cusp and palatal cusp. The stress data were analyzed using analysis of principal stress. Results showed that combining method such that apex was restored by material with high elastic modulus and the occlusal and cervical cavosurface margin by small amount of material with low elastic modulus was the most profitable method in the view of tensile stress that was considered as the dominant factor jeopardizing the restoration durability and promoting the lesion progression.

• Journal of Conservation Science
• /
• v.37 no.3
• /
• pp.282-288
• /
• 2021

This basic research was conducted to support the development of woodcraft bio-adhesives using peach gum, which is the resin produced by peach trees. The synthesis conditions of these adhesives were optimized by performing 144 experiments. The application potential of peach gum adhesives was explored by comparing their properties with those of three natural adhesives and four synthetic adhesives. The best adhesive strength was obtained by dissolving the resin in 80 mL of distilled water containing 1.5 g NaOH, 1.65 g H₂O₂ ( pH 8.0-9.0), 0.5 g NaClO, and 0.5 g H₂BO₂. The adhesive strength, which showed minimal changes and excellent reversibility, was 125.39 kgf/cm². Ultraviolet radiation-mediated deterioration in strength in the absence of total aerobic bacteria was negligible (△E^*ab = 2.75). These data confirm the potential value of peach gum-based bio-adhesives for woodcraft as well as their utility as alternatives for natural and synthetic adhesives used for the manufacture and restoration of handicrafts and preservation of cultural assets.

• Restorative Dentistry and Endodontics
• /
• v.31 no.1
• /
• pp.20-29
• /
• 2006

The purpose of this study was to analyze the stress distribution aspect of unrestored and restored combined shape (wedge shape occulusally and saucer shape gingivally) class V cavity, which found frequently in clinical cases. A maxillary second permolar restored with a combined shape class V composite restorations were modeled using the three dimensional finite element method. Static occlusal load of 170 N was applied on lingual incline of buccal cusp at the angle of $45^{\circ}$ with the longitudinal axis of the tooth. And three dimensional finite element analysis was taken by ANSYS (Version 6.0, Swanson Analysis System Co., Houston, U.S.A) program which represent the stress distribution on unrestored and restored cavity wall and margin. The conclusions were as follows. 1. Compared to the unrestored cavity, Von Mises stress at the cementoenamel junction and line angle of the cavity base were reduced and in restored cavity. 2. Von Mises stress at the occlusal and cervical cavity margin and wall were increased in restored cavity in comparison with the unrestored cavity. 3. In the hybrid and hybrid/flowable composite resin restoration, Von Mises stress at the cementoenamel junction and line angle of the cavity base were reduced more than in the flowable restoration. 4. In the hybrid and hybrid/flowable composite resin restoration, Von Mises stress at the occlusal and cervical cavity margin and wall were increased more than in the flowable restoration.

• Journal of Food Hygiene and Safety
• /
• v.14 no.3
• /
• pp.244-248
• /
• 1999

This study was carried out to determine the contents of sodium saccharin, sodium benzoate and potassium sorbate in danmooji, jangachi, puffed cereal, mixed beverages, carbonated beverages, fruit and vegertable juices (excepted unheated fruit and vegertable juices) and dried fishery products(seasoned) in the market. Sodium saccharin, sodium benzoate and potassium sorb ate were analyzed by HPLC at the wavelength of 215 nm with 0.05% ammonium phosphate dibasic acetonitril mobil phase(94 : 6), and recovery rates were 96.2-100.3%, 95.8-100.9%, 96.1-99.8%, respectively. The contents of sodium saccharin were N.D.-1234.8 mg/kg in danmoogi, jangachi, puffed cereal and mixed beverages and sodium benzoate in mixed beverages, carbonated beverages, fruit and vegertable juices were N.D.-663.2 mg/kg, and potassium sorbate in danmooji, jangachi and dried fishery products were N.D.-2725.2 mg/kg.

• 한국문화재보존과학회:학술대회논문집
• /
• 2002.02a
• /
• pp.21-31
• /
• 2002

Lime-soil consolidations are very important as structural material, bonding material, waterproofing material, and finishing material in korea traditional buildings. In this study, we investigated site application trouble in korea traditional buildings being repaired or restored, and propose following solutions. 1) To diminish quality variation occurred by slaking quick-lime in site, it is desirable to use slaked-lime for lime-soil consolidation. 2) For uniform construction of lime-soil consolidation, we would recommend builders to use mixer to be uniform mixture, premixed type materials and compacting machine in field, 3) and to use rigid suitable temporary construction as scaffold for preventing traditional buildings from additional damage occurred in demolition and construction of a layer of lime-soil consolidation of a roofing. 4) For suitable repair of traditional buildings, it is necessary to specify definitely materials and construction methods suggested by the standard specifications for repair of the cultural property.

• Conservation Science in Museum
• /
• v.27
• /
• pp.91-102
• /
• 2022

Silica-based inorganic fillers for restoration of iron objects have been used for the reduction of thermal expansivity and the improvement of melt flow index. However, the higher the amount of filler is applied, the more degradation of mechanical properties and the yellowing occur, which could cause retreatment of the objects with adding stress to them. Thus, research on not only the quantification of a mixture of resin and filler but also the yellowing should be emphasized. Experiments on mechanical properties were carried out with a silica-based light filler, Micro Shell as a comparison group. The results of the experiment showed Micro Shell reduced the number of occurrences of the yellowing by 34% compared to existing fillers. The value of adhesion and specific gravity was also improved depending on the filler amount. The results of this research indicate the possibility of using Micro Shell as a new filler.