• Title/Summary/Keyword: Bronze

검색결과 569건 처리시간 0.026초

시력교정용 금속테설계의 이론적고찰 (Theoretical Considerations on the Design of Metal Frames for Refractive Correction)

  • 강현식
    • 한국안광학회지
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    • 제3권1호
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    • pp.39-73
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    • 1998
  • 안경테는 국제적으로 대량 교역되는 상품의 하나이다. 그렇기 때문에 오늘날 국제표준화기구(ISO-TC172/SC7/WG2)에서는 독일, 미국, 영국, 이태리, 프랑스, 스페인, 일본 등의 안경관리 전문학자, 기술자, 제조업자 등이 모여 안경테의 국제 간 원활히 하고, 소비자에게는 이익과 service를 제공하고, 제조업자에게는 생산성제고와 제조원가를 절감할 수 있는 국제적 협력을 조장하기 위하여 안경테에 관한 용어, 측정법, 부품규격, 검사 및 시험방법 등에 관한 규정을 제정하고 있다. 그런데도 불구하고 우리나라의 안경업계가 이들 회원국의 활동에 관심이 없다는 것은 안경산업의 장래를 생각할 때 암울하기만 하다. 우리나라는 1970-1980년대에 걸쳐 수출이 연평균 약 20%이상 신장되었으나 1990년대 초반부터 수출실적은 미화 2억달라를 넘어선채 정체상태를 벗어나지 못하고 있다. 그런데 정체된 안경테의 수출을 진흥시키기 위해서는 무엇보다는 신소재와 독자적인 디자인의 개발, 국제표준규격에 준한 설계와 제작, 제조기술의 혁신, 특허정보의 활용 및 국제적인 판촉활동 등이, 활발히 전개되어야 하며, 대구광역시의 섬유기술연구소와 같은 형태의 안경기술연구소 또는 안경전문기술위원회의 발족과 정부차원의 적극적인 지원이 시급한 당면과제이다. 본 논문의 궁긍적 목표는 우리나라 안경제조업자에게 ISO-Working Group2 등이 제정 발표한 안경테의 관계규정 및 규격을 소개하고 금속테를 설계 제작할 때 보완할 이론적 지침을 제시해서 설계상 결함이 없는 금속테를 제작하는데 있다.

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국내연구자가 출판한 국제학술지 논문의 오픈액세스 현황 - 고피인용된 논문 중심 - (Analysis of Open Access Status of Domestic Author's Papers Published in International Journals: Based on Highly Cited Papers)

  • 조재인
    • 한국문헌정보학회지
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    • 제54권1호
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    • pp.325-341
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    • 2020
  • 본 연구는 OA 버전을 추적하는 개방형 도구 중 하나인 Unpaywall API를 이용해 2015년 이후 내국인이 국제 학술지에 출판한 논문 중 고피인용되고 있는 논문 3,905건을 대상으로 OA여부를 실증적으로 파악하였다. 분석 대상 논문의 공개 여부와 방식을 이해하고 학분 분야에 따라 차이가 존재하는지 살펴 본 결과, 다음과 같은 사실을 발견하였다. 첫째, 의학 분야를 제외하면 30%이하의 논문만이 공개되고 있었으며, 공개 방식도 브론즈가 절반 이상을 차지하였다. 둘째, 그린 OA된 논문의 아카이빙 장소는 국내가 아니라 주로 공동저자가 소속된 해외 대학의 기관레포지토리이거나 주제레포지토리인 것으로 조사되었다. 셋째, 연구비 수혜 논문의 경우에도 단지 19.6%만이 공개되고 있으며 그 중 절반은 의학 분야가 차지하는 것으로 나타났다. 마지막으로 OA된 논문이 더 높은 피인용도를 보이는 국제 추세와 달리, 분석 대상 논문은 비 OA 논문에 비해 높은 피인용도를 보이지 않았다.

A Study on the Applicability of Corrosion Inhibitor for Outdoor Copper Alloy

  • Shin, Jeong Ah;Wi, Koang Chul
    • 보존과학회지
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    • 제34권4호
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    • pp.259-271
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    • 2018
  • Outdoor copper alloy is exposed to the atmospheric environment, accelerating corrosion progress compared with indoor copper alloy. In order to prevent corrosion, the outdoor copper alloy is coated with wax to block external corrosion factors. However, corrosion of the inside of the coating film is highly likely to continue without the internal corrosion prevention treatment. B.T.A, which is used as a copper alloy water-soluble corrosion inhibitor, has a high possibility of being harmful to the human body and is mainly used to treat excavated artifacts. This study had selected the water-soluble corrosion inhibitor, which was easier to use than the existing wax and B.T.A being used in corrosion inhibition treatment for outdoor copper alloy. A comparative study was conducted on B.T.A, which is a water-soluble corrosion inhibitor used on excavated artifacts, and $VCI^{(R)}$, $Rus^{(R)}$, and L-cys, an amino acid corrosion inhibitor, used for tin bronze test pieces. The experimental method was conducted for a certain period of time with the salt, acid, and air pollution affecting the corrosion of outdoor copper alloy. Based on experiment results, it was concluded that the best water - soluble copper alloy corrosion inhibitor in the atmospheric environment is $VCI^{(R)}$. and it could be considered to be applied in replacement of B.T.A due to its low harmfulness. In addition, $VCI^{(R)}$ is judged to serve as a corrosion inhibitor for outdoor copper alloy because it showed the best result even in the outdoor exposure test which is a real atmospheric environment.

Manufacturing Techniques of Ancient Metal Buddha Statues from Archaeological Sites in Bagan, Myanmar

  • Lee, Jae Sung;Win, Yee Yee;Lee, Bonnie;Yu, Jae Eun
    • 보존과학회지
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    • 제35권4호
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    • pp.309-316
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    • 2019
  • This study intends to identify manufacturing techniques, including casting and alloy composition, of nine metal Buddha statues excavated from archaeological sites in Bagan, Myanmar. Two Buddha statues from Pyu city state(2nd to 9th century) contain Cu-Sn alloy(including <1 wt% Fe), with different relatively high percentages of Sn(16 wt% and 25 wt%) identified from each Buddha statue, and no Pb detected. Five Buddha statues from the Bagan dynasty contain various alloy ratios of Cu-Sn(including <1 wt% Pb), Cu-Sn-Pb, and Cu-Sn-Zn-Pb. All Buddha statues appear to be fabricated by casting, as there is no evidence of other heat treatments. The silver Buddha statue manufactured in the 18th century includes >1% Cu besides silver with no additional metallic components identified. The bronze Buddha statue manufactured in the Konbaung dynasty(18th century) is of Cu-Sn-Pb alloy. The Buddha statues of Pyu was alloy of Cu-Sn without Pb including ahigh percentage of The Buddha statues of both the Bagan and Konbaung dynasties are comprised of ternary Cu-Sn-Pb alloys, with a heterogeneous distribution of lead and tin. Some of Buddha statues of the Bagan dynasty have similar alloy ratios as those of Pyu, suggesting that similar manufacturing techniques were used.

충남 연기군 동면 합강리 유적 출토 직물류 및 목제 빗의 과학적 분석 (A Scientific Analysis of Archaeological Textiles and Wooden comb Excavated from Hapgang-ri, Dong-myun, Yungi-gun, Chungcheongnam-do)

  • 조남철;김우현;김수철
    • 보존과학회지
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    • 제30권4호
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    • pp.329-334
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    • 2014
  • 고대 섬유의 과학적 분석은 그 시대에 사용된 재료의 특성 및 각 지역의 직물문화, 제직기술 등을 파악할 수 있는 중요한 자료를 제공한다. 또한 수침 고목재의 수종분석은 보존처리 방법의 설정뿐만 아니라 당시의 수목환경, 목제품의 종류에 따라 선호되던 수종, 외래수종을 통한 당시의 교역 교류 등의 정보를 확인할 수 있는 과학적인 분석방법이다. 충남 연기군 동면 합강리 유적에서 청동합 내 부장상태로 출토된 직물류와 목제 빗에 대하여 섬유 및 수종의 종류를 분석한 결과 직물1과 직물3은 쐐기풀과(Urticaceae)의 저마(Boehmeria nivea ; Ramie), 직물2는 아욱과(Malvaceae)의 면(Gossypium herbaceum), 목제 빗은 자작나무과(Betulaceae) 자작나무속(Betula spp.)으로 식별되었다. 이번 연구 결과는 향후 고대 섬유 및 수종을 확인하여 비교 연구하는데 도움이 될 것으로 기대된다.

국내 지구공원 적지 가능성 연구: 변산반도 국립공원 (A Study on the Possibility as a Site for Geopark in Korea: Byeonsanbando National Park)

  • 허철호
    • 한국지구과학회지
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    • 제28권1호
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    • pp.136-141
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    • 2007
  • 유네스코의 지구과학분과는 세계적으로 지구과학적 유산을 알리기 위해 지구공원 프로그램을 개발해왔다. 본인은 한국에서 최초의 지구공원으로 변산반도국립공원을 제안하며 지구공원의 지정을 가능케하는 증거들을 제시하고자 한다. 변산반도 국립공원은 지질학적, 지형학적, 생태적, 문화적 자원들을 보유하고 있다는 장점이 있다. 채석강과 적벽강에는 과학적 흥미를 유발하는 많은 지질 및 지형학적 자원들이 부존되어 있다. 게다가, 변산반도 국립공원은 844종의 야생식물과 550종의 야생동물을 보유하고 있는 생태계의 보고이다. 내소사의 고려 동종과 개암사의 대웅전을 포함해서 문화유산도 풍부하다. 유네스코의 지구공원으로 지정되기 위해서는 환경부산하의 국립공원관리공단과 관련 지방자치단체 주도하에 지질, 지형, 생태, 문화자원외에도 지질관광의 운영계획도 요구된다. 상기한 조건들이 충분히 충족되면, 지구공원의 전지구적 네트워크가 한국에서 최초로 구축되리라 생각된다.

조선시대 남자(男子)의 수식(首飾) 연구(I) (A Study on Korean Man's Head Ornaments in the Joseon Dynasty)

  • 장숙환
    • 한국의상디자인학회지
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    • 제10권1호
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    • pp.99-116
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    • 2008
  • This study reviewed pertinent literature and examined relics of manggon(a headband worn to hold a man's topknot hair in place), donggot(a topknot pin), and chigwan(a topknot cover). Before the modernized short hair style, wearing a gat was an important custom. Therefore, manggon, which was used to hold a man's hair in place under the gat, was considered an essential part of the man's official dress code. Donggot is a pin that held the topknot hair in place. It was a must have for a married man, like the binyeo, a lod-like hairpin, for a married woman. Unlike gwanja, it had nothing to do with official rank, but materials were of a variety of materials, including jade and gold. The structure of the donggot was studied in three parts-head, neck and body. Major forms for the head include the mushroom, bean and ball. Bullet and half-cut bullet forms were also found. Forms for the neck include straight-neck and curved-neck. A neck with a belt around a double chin was also found. Forms for the body include the tetrahedron, octahedron and cylinder. The most popular form for silver and white bronze donggot heads was the mushroom, followed by bean and pile forms. Chigwan is also called chipogwan, chichoal, choalgyesogwan, noingwan and sangtugwan. In poetry it was called chichoal, and it used to be called taegogwan in the past as well. Chigwan was so small that it managed to hold a topknot. According to confucian custom in the Joseon period, by wearing chigwan, men didn't display their bare topknot even when they didn't dress up. When they went out, they wore another official hat over the chigwan.

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SBN60 박막의 결정화 및 전기적 특성에 관한 씨앗층의 영향 (Effect of Seed-layer on the Crystallization and Electric Properties of SBN60 Thin Films)

  • 장재훈;이동근;이희영;조상희
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.2
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    • pp.723-727
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    • 2003
  • [ $Sr_xBa_{1-x}Nb_2O_6$ ] (SBN, $0.25{\leq}x{\leq}0.75$) ceramic is a ferroelectric material with tetragonal tungsten bronze (TTB) type structure, which has a high pyroelectric coefficient and a nonlinear electro-optic coefficient value. In spite of its advantages, SBN has not been investigated well compared to other ferroelectric materials with perovskite structure. In this study, SBN thin film was manufactured by ion beam sputtering technique using the prepared SBN target in $Ar/O_2$ atmosphere. SBN30 thin film of $1000{\AA}$ was pre-deposited as a seed layer on $Pt(100)/TiO_2/SiO_2/Si$ substrate followed by SBN60 deposition up to $3000{\AA}$ in thickness. As-deposited SBN60/SBN30 layer was heat-treated at different temperatures of 650, 700, 750, and $800^{\circ}C$ in air, respectively The crystallinity and orientation behavior as well as electric properties of SBN60/SBN30 multi-layer were examined. The deposited layer was uniform and the orientation was shown primarily along (001) plane from XRD pattern. There was no difference in the crystal structure with heat-treatment temperature, but the electric properties depended on the heating temperature and was the best at $750^{\circ}C$. In electric properties of Pt/SBN60/SBN30/Pt thin film capacitor prepared, the remnant polarization (2Pr) value was $15{\mu}C/cm^2$, the coercive field (Ec) 75 kV/cm, and the dielectric constant 1075, respectively.

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The Effect of Annealing Heat Treatment by Anodic Polarization Impedance Experiments for Cu-10%Ni Alloy

  • Lee, Sung-Yul;Moon, Kyung-Man;Jeong, Jae-Hyun;Lee, Myeong-Hoon;Baek, Tae-Sil
    • Journal of Advanced Marine Engineering and Technology
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    • 제39권5호
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    • pp.536-541
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    • 2015
  • Copper has been used extensively as an electric wire or as a base material in various types of machineries owing to its good electrical and thermal conductivity and good fabricating property, as well as its good corrosion resistance compared to iron. Furthermore, the copper-nickel alloy has significant corrosion resistance in severely corrosive environments. Although, cupro-nickel alloy shows better corrosion resistance than the brass and bronze series, this alloy also corroded in severely corrosive environments, including aggressive chloride ions, dissolved oxygen, and condition of fast flowing seawater. In this study, and annealing treatment at various annealing temperatures was carried out on the cupro-nickel (Cu-10%Ni) alloy, and the effects of annealing were investigated using electrochemical methods, such as measuring the polarization and impedance behaviors under flowing seawater conditions. The corrosion resistance increased by annealing compared to non heat treatment in the absence of flowing seawater. In particular, the sample annealed at $200^{\circ}C$ exhibited the best corrosion resistance. The impedance in the presence of flowing seawater showed higher values than in the absence of flowing seawater. Furthermore, the highest impedances was observed in the sample annealed at $800^{\circ}C$, irrespective of the present of flowing seawater. Consequently, the corrosion resistance of cupro-nickel (Cu-10%Ni) alloy in a severely corrosive environment can be improved somewhat by annealing.

고려시대 가구재료 연구 (A Study on the Material of Furniture in Goryeo)

  • 조숙경
    • 한국가구학회지
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    • 제25권1호
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    • pp.19-27
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    • 2014
  • This paper studied the materials of the furniture which the noble men used in Goryeo, based on the furniture material category of solid wood furniture, lacquerware inlaid with mother-of-pearl and hardware. As for the solid wood furniture, the wood and furniture types are inferred based on the documents. The trees used for the wood furniture were zelkova, korean willow, pine, royal paulownia, maidenhair tree, korean pine, chinese juniper and elm. The furniture types were table, chair, wooden bench, small portable table, writing table, and folding screen. As to the types of lacquerware inlaid with mother-of-pearl, most of them were hams with top, which were made of abalone shells. The features of the lacquerware inlaid with mother-of-pearl were in detail and elaborate like the pattern of the full bloomed chrysanthemum. Writing tables were also made of lacquerware as pieces of furniture. Distinctively, the mother-of-pearl furniture material was popular enough to be used even in a horse saddle. Regarding the metal feldspar used as both a practical use and decoration, there are drop handle, hinge, the front basis, and lock seen in the artifacts, which were made of cast iron, bronze, and brass. Their manufacture techniques were eojamoon, bratticing and sheet metal. Through this study of the furniture materials used in Goryeo, it seems that Goryeo furniture focused on the functions rather than on the decorations, and in turn the forms were simple and basic. The technique of mother-of-pearl, a bit elaborate one, was used in the props furniture like kitchen wares, hams, or writing talbes. Probably, the solid wood is inferred to be used in a low wooden bench, a chair, and a table based on the documents.

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