• Bulletin of the Korean Chemical Society
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• 제28권2호
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• pp.339-342
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• 2007

• Nuclear Engineering and Technology
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• 제54권10호
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• pp.3841-3848
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• 2022

The effect of modifiers on the optical features and radiation defying ability of the Eu³⁺ ions doped multi constituent glasses was examined. XRD has established the amorphous nature of the specimen. The presence of various functional/fundamental groups in the present glasses was analyzed through FTIR spectra. The physical, structural and elastic traits of the glasses were explored. The variation in the structural compactness of the glass structure according to the incorporated modifier was enlightened to describe their suitability for a better shielding media. For the examined glasses, the metallization criterion value varied in the range 0.613-0.692, indicating the non-metallic character of the glasses with possible nonlinear optical applications. The computed elastic moduli expose the Li-containing glass (BTLi:Eu) to be tightly packed and rigid, which is a requirement for a better shielding channel. Furthermore, the optical bandgap and the Urbach energy values are calculated based on the optical absorption spectra. The evaluated bonding parameters revealed the nature of the fabricated glasses covalent. In addition, we investigated the radiation attenuation attributes of the prepared Eu³⁺ ions doped multi constituent glasses using Phy-X software. We determined the linear attenuation coefficient (LAC) and reported the influence of the five oxides Li₂O₃, CaO, BaO, SrO, and ZnO on the LAC values. The LAC varied between 0.433 and 0.549 cm^-1 at 0.284 MeV. The 39B₂O₃-25TeO₂-15Li₂O₃-10Na₂O-10K₂O-1Eu₂O₃ glass has a much smaller LAC than the other glasses.

• 공업화학전망
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• 제24권3호
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• pp.1-13
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• 2021

유리 소재는 뛰어난 기계적, 화학적, 광학 특성으로 인해 다양한 영역에서 광범위하게 활용되어 왔으며, 최근에는 특정 물성이 강화된 기능성 유리 수요가 다양한 산업 영역에서 급속히 증가하고 있다. 유리 소재 분야에서의 연구 개발은 유리 특유의 비정질 구조 및 다원소 조성 특성에 의한 복합성 때문에 전통적으로 경험에 기반한 실험 기법에 의존하여 왔다. 그러나 적용 분야에 따른 맞춤형 물성 강화에 대한 필요성이 증대됨에 따라, 핵심 물성 발현 원리 등을 원자 단위에서 이해하고 이를 바탕으로 기능성 유리 소재를 설계하는 접근법이 주목받고 있다. 원자단위 시뮬레이션 및 이론 기반 모델링은 유리 소재의 다양한 물성과 조성 변화에 따른 원자 구조의 상관관계를 매우 효율적으로 분석할 수 있는 기법이다. 본 기고문 에서는 밀도범함수이론, 분자동역학 및 위상속박이론을 활용한 기능성 유리 소재 개발 및 연구 동향에 대해서 소개하고자 한다.

• 세라미스트
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• 제10권3호
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• pp.91-97
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• 2007

Femtosecond laser micro-processing received much attention in the past decade. The nature of ultra-short light-matter interaction permits femtosecond laser to overcome the diffraction limit and realize precise micro-processing. The ultrahigh light intensity of the femtosecond laser allows sapece-selective microscopic modifications to materials based on multiphoton processes. In this paper, we review our recent research development on space-selective precipitation and control of functional crystals in glasses by an infrared femtosecond laser. The technique will open new possibilities in the fabrication of micro-optical components with various optical functions.

• 전력전자학회논문지
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• 제20권2호
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• pp.105-114
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• 2015

Heated glasses are widely used to prevent surface condensation and freezing in ship and building windows. This study proposes a heated glass temperature control system composed of power and control circuits to control the temperature of heated glasses. The proposed temperature control system adopts a digital controller instead of a conventional analog controller. Thus, the proposed system has better characteristics, such as precise setup and control of glass temperature, setup and control of output power, and control mode change between ON/OFF and phase controls. The system can also implement multi-functional control algorithms. The control characteristics are not dependent upon external disturbances, such as ambient temperature and electrical noises. Furthermore, the proposed temperature control system utilizes the power line communication (PLC) method to control the number of heated glasses without any extra communication lines. The system proposes a new communication protocol with strong immunity to electrical switching noises. A new sensorless algorithm is used to detect the temperature of the heated glass. This study presents the design guidelines in detail and its effectiveness are confirmed by implementing a 4-kw prototype temperature control system.

• KIEAE Journal
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• 제4권2호
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• pp.11-18
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• 2004

Growing use of entire glass facades with metal frames are popularly witnessed in modern building practices and design competition as well. In spite of architectural aesthetics and view to outdoors, environmental issues still exist in that kind of buildings. One of the solutions for the problems might be the use of functional glasses such as a heat-resistant glass or various tinted glasses for the glass walls. This paper aims to provide performance data related to the impact of various transmittal materials of window systems on the light distribution. A series of computer simulation deals with the basic geometrical and optical design elements of a commonly used all-glass facades. Additionally an experimental configuration of the vertical window is proposed for better result of daylighting. A window system equipped with an inner-light shelf can improve the uniformity of natural light in a space by reducing the level of illumination near the window and redirecting light deeply into the space.

• 통상정보연구
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• 제15권4호
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• pp.27-46
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• 2013

본 연구는 중국 안경시장을 대상으로 국산 안경제품이 현지 시장에서 어느 정도의 경쟁력을 가지고 있고 경쟁력이 어떻게 변화하고 있는가를 고찰하기 위해 한국 안경산업의 현황과 대중국 수출성과 및 SWOT 분석을 실시한 후 이로부터 국산 안경제품의 중국시장 수출 활성화에 대한 시사점을 제안한다. 분석을 위해 한국무역협회 통계자료에서 2003년부터 2012년까지의 안경제품의 수출입 자료를 추출하고 이를 토대로 시장점유율지수, 무역특화지수, 현시비교우위지수를 산출하여 분석하였다. 대중국 수출현황 분석 결과 한국 안경산업은 만성적인 적자를 기록하고 있는 상황에서 현지 시장 점유율은 평균 5% 미만이었고, 품목별로는 콘택트렌즈가 흑자를 지속하고 있는 반면 안경테, 안경, 안경렌즈, 선글라스는 적자를 보였으며, 분석지수를 활용한 수출성과 분석에서도 콘택트렌즈만이 경쟁력을 확보하였을 뿐 전반적으로 국산 안경제품의 대중국 경쟁력은 낮게 나타났다. 연구 결과는 한국 안경제품의 대중국 수출 활성화를 위해서는 현지 시장의 니즈를 충족하는 창의적이고 차별화된 제품 디자인 개발 능력을 강화하고 신소재의 다양한 기능을 갖춘 제품을 개발하며 현지 시장에 지속적인 신제품 출시를 통해 브랜드 인지도를 향상시켜 가야 함을 시사하고 있다. 아울러 국내외 기업과의 전략적 제휴 및 현지에서 한류 마케팅을 적극 추진하고 비정상적인 제품의 유통구조를 합리적으로 개선하며 정부의 체계적인 지원시스템이 마련되어야 함을 시사한다.

• Nuclear Engineering and Technology
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• 제44권1호
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• pp.9-20
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• 2012

A brief review on the thermal plasma synthesis of nano-sized powders is presented according to the application materials, such as, metals, ceramics, glasses, carbonaceous materials and other functional composites, such as, supported metal catalyst and core-shell structured nano materials. As widely adopted plasma sources available for thermal plasma synthesis of nanosized powders, three kinds of plasma torches, such as transferred and non-transferred DC and RF plasma torches, are introduced with the main features of each torch system. In the basis of the described torch features and the properties of suggested materials, application results including synthesis mechanism are reviewed in this paper.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2004년도 추계학술대회논문집
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• pp.44-47
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• 2004

Although bulk metallic glasses have many outstanding aspects in their chemical, mechanical or functional properties, some critical problems still hinder their wide application. The most important one is the brittle nature of them, which is the serious problem to structural application. So, to use viscous flow is now the only competent way to form bulk metallic glass. In this study, we investigated the basic nature of viscous flow of Zr-base bulk metallic glass, vitrelloy 1, in terms of process variables. The results were used to design the thermo-mechanical process composed of heating, holding, pressing, and cooling, which have unique influence on the glass transition and crystallization behavior. We adopted small load scale and dies with nano/micro patterns on them. The results were evaluated using several analytical methods.

• 반도체디스플레이기술학회지
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• 제10권1호
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• pp.75-81
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• 2011

Today, FPD manufactures are eager to develop larger and larger glass to become the prime market leader. To follow this need, larger AMHS(Automated Material Handling System) development is essential. The radical increase of glass/cassette weight puts a lot of pressure on stocker robot's dual arms, which can cause a damage of expensive glasses and contaminate a clean room facility. In this paper the axiomatic design method is used to institute a design guideline to evenly distribute a pressure throughout the stocker robot structure.