• 제목/요약/키워드: natural weathering

검색결과 145건 처리시간 0.032초

천연 접착제를 활용한 사찰벽화 화벽층의 충전 재료연구 (Study on the filling material for the painting wall layer of the temple wall painting using a natural adhesive)

  • 김순관;정혜영
    • 보존과학연구
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    • 통권29호
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    • pp.255-278
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    • 2008
  • Considering the physical quality of the wall body in this study we tried to select a replenishing that is proper for filling the cracked part of the painting wall layer and apply the natural adhesives that have traditionally been used, investigating whether it is possible to substitute those for the chemical adhesive which is used at present time. The result of this study showed the red algae adhesive was, in a weathering environment, as safe as the synthetic resin originated from the polyvinyl acetate which is used generally on the present spot, and it was concluded that although the starch adhesive displayed its superiority in enhancing the strength of the earth mortar and its work disposition, it seemed proper for it to be used as a filling adhesive for the first or midterm layer because it showed a surface hardening phenomenon. And also the glue and fish glue were judged they were not qualified as a filling adhesive due to mold occurring in a environment of high moisture that is a biological problem, showing at same time a weak physical feature in a weathering environment. Therefore it would be possible to use the red algae adhesive or starch one substituting them for the original one sold on the present market, if among natural adhesives the weak points of the them were to be corrected.

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석굴암을 이루는 암석의 풍화현상 (Weathering Phenomena of the Rocks Constituting the Seoggulam)

  • 이상헌
    • 보존과학회지
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    • 제8권1호
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    • pp.1-9
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    • 1999
  • 석굴암은 해체, 복원 및 수차례에 걸친 보수과정을 거쳐 지금에 이르렀다. 현재와 같은 비교적 안정된 환경이 이루어지기 전 까지 오랜 시간에 걸친 자연적인 풍화와 사람에 의한 영향 등에 의해 많은 변화를 겪어 왔다. 석굴암을 이루는 암석은 중립 내지 조립질의 화강섬록암으로 대체로 갈색에서 암갈색에 이르는 풍화면을 보이는데 이는 이 암석의 주구성광물인 장석류의 화학적 풍화에 기인한다. 또한 콘크리트돔이나 균열된 곳에 사용된 시멘트의 풍화물에 의한 표백 및 백화 현상 등에 의해 부분적으로 우백색을 띠거나 때로는 매우 검게 변색되어 있기도 한다. 여러 곳에 크고 작은 균열들이 발달되어 있으며 이는 주로 오랜 풍화작용에 의한 영향과 해체-복원 및 보수 과정중의 충격등에 기인하는 것으로 생각된다. 이러한 일반적인 현상들은 대부분이 현재와 같은 비교적 안정된 환경이 갖추어지기 전에 이루어진 것으로 생각된다. 그러나 앞으로의 더 나은 보전을 위해서는 내부 공기의 온도와 습도, 특히 위치에 따른 상대습도의 지속적인 평형유지, 구조적 균형유지, 그리고 진동 등에 의한 영향을 체계적이고 계속적으로 측정하여 대책을 수립하여야 할 것으로 생각된다.

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인공풍화가속실험을 통한 울릉도에 분포하는 화산암의 풍화특성 고찰 (Artificial Accelerated Weathering of Volcanic Rocks from Ulleungdo Island)

  • 우익
    • 지질공학
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    • 제25권4호
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    • pp.499-510
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    • 2015
  • 이 연구에서는 울릉도에 분포하는 현무암질 각력암과 조면암, 화산각력암의 풍화특성을 울릉도의 기후조건을 고려하여 설계한 인공풍화가속실험을 이용하여 고찰하였다. 암석 시료는 XRF 결과를 이용하여 도시한 TAS diagram에 따라 화산암 종류를 판별하고 XRD 분석으로 조성광물을 확인한 후, 시료를 일차적으로 구분하였으며, 이차적으로 흡수율에 의해 시료의 풍화정도에 따라 구분하였다. 인공풍화가속실험 결과, 흡수율 증가는 대부분의 시료에서 발생하였으나, 화산각력암을 제외한 대부분의 시료에서는 강도 저감이 발생하지 않았다. 특히, 조면암의 초기 흡수율이 크면 인공풍화가속실험에 따른 흡수율 증가률이 더욱 증대되었으며, 화산각력암은 기타 암석보다 높은 흡수율 증가와 점하중강도 감소를 보여주고 있다. 이러한 실험 결과로 조면암의 화학적 풍화속도가 시간에 따라 가속될 수 있다는 것을 예측할 수 있고, 화학 및 물리적 풍화에 대한 저항성이 약한 화산각력암은 짧은 시간에서도 감소가 발생할 수 있다는 것을 파악할 수 있었다. 따라서, 이러한 암석들이 분포하고 있는 일주도로에서는 낙석 및 산사태와 같은 자연재해에 대한 대책이 필요한 것으로 판단된다.

중장비용 우레탄 도료 내후성 가속시험 (Accelerated Weathering Test of Urethane Paint for Heavy Construction Equipment)

  • 김대용;김영준
    • 한국신뢰성학회지:신뢰성응용연구
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    • 제1권2호
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    • pp.79-93
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    • 2001
  • Recently, new aspects of paints such as a beautiful appearance, use of environmentally friendly paints, etc., in addition to the superior performance of paints have been requested for industrial paints including the paints for heavy construction equipment and others. Particularly, the quality of appearance of coating affects the sales of heavy construction equipment. And the necessity for the paints to have a superior weather-proof property without changing the luster or color even after long-time exposure to the open air is emphasized. The change in the surface color and luster of the paint due to the natural environment progresses very slowly, and it takes a long time to verify material properties when developing new paints. In order to improve such methods, weathering tests are performed in many laboratories as a test for accelerating aging of coating, and the lifetime of the products is estimated through evaluation of the weathering (environment-proof) quality of paints. However, not a great deal of research activity has been conducted up to the present time since the interrelationship between the actual results of testing and field data is different for each paint and it takes a long time to study relevant materials. Therefore, introduced in the present study is the estimation of the change in the quality of appearance of coating in the field through the accelerated aging test among the cases of improvement of the quality of appearance of the urethane paint for heavy construction equipment.

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부여 무량사오층석탑의 종합 풍화훼손도 평가 (Synthetic deterioration assessment of the five storied stone pagoda in the Mooryangsa temple, Buyeo, Korea)

  • 송치영;이미혜;조영훈;이찬희
    • 보존과학연구
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    • 통권27호
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    • pp.103-128
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    • 2006
  • Rock properties of the five storied stone pagoda in the Mooryangsa temple are consist mainly in medium grained biotite granite with partly pegmatite veinlet. A part of the foundation stone is substituted in identical rock properties of the pagoda. The upper part of the pagoda is used purples and stone, gray shale and granodiorite. The most serious problem of the pagoda is structual instability from centered subsidence of the ground in northwestern direction remarkably. In southern view, the upper part of the pagoda also is slanted a little in right, it will need reinforcement by engineering method for structual stability of the stone pagoda. Weathering states of the stone pagoda are affected results of natural and artifical factors due to the surface-exfoliation, fine-fissure, crack, falling offs. On the rock surface of the pagoda, ferro-manganese hydroxide compounds are coated along the rainpathway. Also, bryophyte range concentration spreads raindrops face of roof rock properties, which areadd biological weathering effects. For the synthetic evaluation of the deterioration state, we make detailed surface weathering maps, it will be contribute to investigation for future conservation schemes.

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자연 지역으로서의 태백 산지 (Taebaek Mountainous Region as a Natural Unit)

  • 기근도
    • 한국지역지리학회지
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    • 제8권4호
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    • pp.468-479
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    • 2002
  • 태백 산지는 대체로 냉량하고 습한 편이지만, 강수량은 지역적으로 많은 차이를 나타내고 있다. 이와 같은 기후지형 환경과 관련하여 태백산지의 지형 및 토양환경은 기반암의 유형에 따라서 차이를 보인다. 북부의 금강산과 설악산 같은 화강암 분포 지역은 절리밀도의 차이를 반영하는 풍화 성향 때문에 암괴 노출이 심한 산지를 이루며, 미시령 일대의 편마암 분포 지역은 전사면이 흙으로 덮여있고 상대적으로 식생밀도가 높은 곳이다. 중부에서는 암괴 노출이 심한 타지역의 화강암산지와는 달리 박토상태지만 대체로 전사면이 흙으로 덮여있다. 이는 이 지역이 눈이 많고 서릿발 작용이 활발하여 화강암을 얇게나마 풍화시킬 수 있었기 때문이다. 남부에서는 급사면의 뾰족한 봉우리와 좁고 깊은 협곡을 이루는 석회암산지 및 완만한 사면지역의 여러 가지 용식지형이 발달한다. 이 지역에는 초본류나 관목류들이 연속성이 높게 분포하여 박토상태인 토양을 잘 보전하고 있다.

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폭우시 산사태 특성에 관한 연구 (암종에 따른 특성 연구) (A study on the characteristics of landslide in heavy rainfall (a study by rock types))

  • 이수곤;박지호;선건규
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2003년도 봄 학술발표회 논문집
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    • pp.131-136
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    • 2003
  • Landslide is a natural disaster frequently noticed In korea during monsoon season in flicting nationwise damages on human lives, properties, transportation networks, construction sites, etc. This study is about landslide characteristic in rainfall. This study selects seven sites that occured in 2001 and 2002. So elect areas divide and studied special quality by carcinoma by igneous rock, metamorphic rock, sedimentary rock. According to study finding, because igneous rock area is very thin into 1m interior and exterior soil layer, failures happened much rock and soil interface. There was place that depth of soil layer becomes about 2∼3m being area that receive serious weathering case of metamorphic rock. Therefore, at collapse much debriflow occurrence expect. Case that sedimentary rock area is broken through stratification looked. When see such results, it may become many helps to study characteristics of landslide occurrence area grasping collapse special quality by rock type.

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석조문화재의 생물학적 손상과 보존방안 (The biodeterioration and conservation of stone historical monuments)

  • 정용재;서민석;이규식;한성희
    • 보존과학연구
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    • 통권24호
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    • pp.5-28
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    • 2003
  • Stone has been one of the most intensely studied materials in conservation. Understanding the deterioration of stone needs various knowledge in different mineralogical and physical characteristics and its weathering response under different climate and environment. The alteration and weathering of stone is affected by natural or artificial elements whether they are physical, chemical or biological damaging factors. It can be said that the bio deterioration of stone is coupled with every environmental factors, which induce decomposition of stone structure, either directly or indirectly as a form of catalysis. Many elements contribute to the deterioration of stone monuments and other objects of cultural value such as pagoda, stature of Buddha, etc. This report concentrates on the action of biodeteriorative factorsincluding bacteria, algae and higher plants. Preventive and remedial methods and a selection of chemical treatments are also described.

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악안면 보철용 실리콘의 물리적 특성 및 색조안정성에 관한 연구 (A STUDY ON THE PHYSICAL PROPERTIES AND COLOR STABILITY OF MAXILLOFACIAL PROSTHETIC SILICONE MATERIAL)

  • 박찬진;김창회;김영수
    • 대한치과보철학회지
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    • 제35권2호
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    • pp.330-343
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    • 1997
  • Extraoral maxillofacial prostheses are essential for restoring facial structures that are lost as a result of congenital missing, injuries from accidents, surgical treatments of head and neck cancer. Recently, silicone is the most useful material for this purpose and is more advantageous than other maxillofacial prosthetic materials. However, there are some problems for long-term usage of silicone prostheses due to tear and color change. These are major contributing environmental factors to those problems that are such as ultraviolet light, cleansing agents, changes in humidity and successive adhesion and removal. The aim of this study is to evaluate the physical properties and color changes of maxillofacial prosthetic silicone material by those environmental factors using A-2186 silicone material (Factor II, USA) and two pigments, cadmium yellow medium and cosmetic red. Aluminium molds were fabricated according to the ASTM No. D412 & D624 specifications and resulted specimens from molds were fabicated and treated as follows. Control group and experimental I group were fabricated with 0.1% wt. pigment mixing in silicone elastomer and II-1 group, II-2 group of experimental II group were fabricated with 0.2%, 0.3% wt. pigment mixing in silicone elastomer, respectively. Control group was kept in darkroom at room temperature, I-1 group was kept under natural sunlight during 1week, I-2 group was soaked in 20% soap water during 1wk. I-3 group was successively adhered and removed 200 times on inner region of arm using Daro adhesive-33. Experimental II groups were kept in darkroom at room temperature. Instron universal testing machine was used to measure the % elongation, tensile strength, tear strength of control, experimental I, II groups and reflectance spectrophotometer(COLOR EYE-3000, Macbeth, USA) was used to measure the color differences between control group and experimental I group. The results were as follows : 1. When compared with control group, natural weathering group and 20% soap-water soaking group had no significant differences in % elongation(p>0.05). 2. 200 times successive adhesion and removal group, 0.2% wt. pigment group and 0.3% wt. pigment group had significant decreases in % elongation(p<0.05). 3. Natural weathering group, 20% soap-water soaking group and 200 times successive adhesion and removal group had no significant differences in tensile strength (p>0.05). 4. 0.2%, 0.3% wt. pigment groups had significant decreases in tensile strength(p<0.05). 5. Values of all experimental groups were decreased in tear strength. and 200 times successive adhesion and removal group had significant decrease in tear strength(p<0.05). 6. Natural weathering group and 20% soap-water soaking group had significant color differences(${\Delta}E$) and it could be detectable to naked eye(p<0.05). 7. Color differences between control group and 200 times adhesion and removal group were not detectable to the naked eye (${\Delta}E<1.0$).

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우리나라 자연사면 산사태지역의 강우, 지질 및 산사태 기하형상 고찰 (Characteristics of Rainfall, Geology and Failure Geometry of the Landslide Areas on Natural Terrains, Korea)

  • 김원영;채병곤
    • 지질공학
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    • 제19권3호
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    • pp.331-344
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    • 2009
  • 1990년 이후 우리나라의 자연사면에서 발생한 10개 대규모 산사태지역의 강우조건, 지질특성 및 기하형상에 대한 기존 자료를 재조명하였다. 이들 중 화강암 지역이 5곳, 화강암과 변성암류가 같이 분포하는 지역이 4곳이며, 나머지 1곳은 반려암이 분포한다. 총 3,435개의 산사태 중 1,992개는 화강암 분포지에서, 824개는 변성암 지역에서, 15개는 반려암에서, 그리고 나머지 604개의 산사태는 2개 지역에 부분적으로 분포하는 화산암, 퇴적암 등에서 발생하였다. 연구지역의 산사태는 강우기간 보다는 강우강도에 의하여 좌우되었다. 산사태지역의 강우자료를 Caine과 Olivier의 경험식에 적용하면 모두 Caine의 기준치(threshold)와 Olivier의 산사태반응지수(coefficient of final response)를 초과하여, 모든 지역의 강우조건이 산사태 발생조건을 충족하고 있다. 산사태의 형태와 발생 메카니즘은 기반암의 풍화특성에 따라 차이를 보이고 있다. 화강암 지역은 노두가 거의 없고 풍화심도가 고르게 분포하여 소규모의 슬라이드가 우세하다. 반면 변성암 지역은 지형이 다소 험준하고 노두가 능선과 산록에 발달하여 풍화노두가 토층과 함께 파괴, 유동하는 비교적 큰 규모의 토석류가 우세하다.