• Electrical & Electronic Materials
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• v.4 no.2
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• pp.105-113
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• 1991

본 연구에서는 도전성 고분자인 포리파라훼니렌, 포리파라훼니렐비닐렌 및 포리치오휀을 화학적 및 전기화학적 합성에 의해 필림으로 합성하였으며 각종 도판트가 이들 고분자의 특성에 미치는 영향을 조사하였다. 이들 고분자는 이상적인 도우핑의 조건에서 미량의 도우프영역에서도 도전율은 분자 구조에 의해서 $10^{-4}$~$10^{2}$[S/cm]까지 현저히 증가하는 특성을 나타내었으며 또한 광학적 성직도 변화하여 가전자대와 전도대 사이에 새로운 준위가 형성이 되어 스핀 밀도의 증가와 선폭의 감소를 나타내었다.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2007.11a
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• pp.109-111
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• 2007

Pulsed DC 마그네트론 스퍼터링 장치를 이용하여 Polymer 및 Glass 기판 위에 $SiN_{\chi}$ (Silicon Nitride) 박막을 합성 시키고 이들의 구조적, 광학적 특성을 조사하였다. 막두께는 100 nm로 고정하였으며, power mode 및 질소 가스 유량비를 변수로 합성하였다.

• Journal of the Korean Society of Clothing and Textiles
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• v.6 no.1
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• pp.67-72
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• 1982

이 해설문에서는 최근 수년간 개발된 합성섬유에의 Comfort 가공 : Polyester 섬유의 촉감 개선, 소수성섬유에 있어서 친수성을 향상시키기 위한 화학적인 처리, 대전방지가공, 오염방지가공, 그리고 유연제에 대한 것을 문헌조사를 통해 소개하고 있다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.5
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• pp.1-6
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• 2019

Organic dye-doped silica nanoparticles are used as a promising nanomaterials for bio-labeling, bio-imaging and bio-sensing. Fluorescent silica nanoparticles(NPs) have been synthesized by the modified $St{\ddot{o}}ber$ method. In this study, dye-free fluorescent silica NPs of various sized were synthesized by Sol-Gel process as the modified $St{\ddot{o}}ber$ method. The functional material of APTES((3-aminopropyl)triethoxysilane) was added as an additive during the Sol-Gel process. The as-synthesized silica NPs were calcined at $400^{\circ}C$ for 2 hours. The surface morphology and particle size of the as-synthesized silica NPs were characterized by field-emission scanning electron microscopy. The fluorescent characteristics of the as-synthesized silica NPs was confirmed by UV lamp irradiation of 365 nm wavelength. The photoluminescence (PL) of the as-synthesized silica NPs with different size was analyzed by fluorometry. As the results, the as-synthesized silica NPs exhibits same blue fluorescent characteristics for different NPs size. Especially, as increased of the silica NPs size, the intensity of PL was decreased. The blue fluorescence of dye-free silica NPs was attributed to linkage of $NH_2$ groups of the APTES layer and oxygen-related defects in the silica matrix skeleton.

• Journal of the Earthquake Engineering Society of Korea
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• v.3 no.3
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• pp.55-62
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• 1999

For the efficient performance of steel and composite building structures subjected to strong earthquake, one of current research investigates the cyclic behavior of open-web composite beams. Both experimental test and nonlinear FEM analysis demonstrate their behavior so ductile that four T-sections around the corners of rectangular web-opening develop plastic hinges prior to potential brittle failure at the beam end, i.e. at the column face. This research proposes simplified equations for determining strength and initial stiffness of composite beams with a rectangular web-opening, and compares its results with those of experimental test and nonlinear FEM analysis.

• Survey Research
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• v.10 no.2
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• pp.97-114
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• 2009

Even the importance and necessity of a basic national statistical survey, the population and housing census is facing with some practical difficulties such as higher survey cost, decrease of survey information and much longer survey period. As an alternative to the traditional census for tackling such difficulties, a rolling census has been introduced. The rolling census has some advantages such as improved timeliness with much more frequent data and evenly distributed survey cost over several years. On the contrary, the rolling census has also some disadvantages such as the lost of snapshot feature of the population and increasing risk of outside influence on field work. In this paper we reviewed the French rolling census and the American community survey as roiling surveys, and then investigated some factors like balanced sample selection, population update, synthetic estimation, and the operation of rolling survey, which are to be checked carefully in case of introducing a rolling census as an alternative to the current census.

• Microbiology and Biotechnology Letters
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• v.20 no.6
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• pp.642-646
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• 1992

We have isolated conditional lethal mutants of Saccharomyces cerevisiae which are low in (1 ~3)-~-D-glucan synthase activity. These mutants were osmotic sensitive at nonpermissive temperature (37$^{\circ}$C) and showed a decreased level of alkali-insoluble cell wall glucan. The decrease in (1 ~3)-~-D-glucan synthase activity of the mutants appeared to be mainly due to the defect in catalytic component rather than in GTP-binding component.

• Journal of the Korean Ceramic Society
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• v.25 no.3
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• pp.268-276
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• 1988

Ba or La-Substituted lead niobate $(Pb_{1-x}Ba_x)_{1-y}La_{2y/3}Nb_2O_6$(PBLN), powders having needle shape are prepared by flux method using KCl and the effect of Ba or La substitution on morphology of obtained powders is examined. From these needle shape powders, grain-oriented ceramics are made by doctor-blade method and two-stage hot-pressing technique. The dielectric, piezoelectric and optical properties of the ceramics are also investigaated. Heating condition and the amount of substituted Ba or La have remarkable effects have large anisotropy in both permittivity and coupling factor depending on the pressing direction.

• Korean Journal of Materials Research
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• v.7 no.1
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• pp.8-14
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• 1997

DLC막은 여러가지 기술적인 응용에 매우 기대된느 재료이다. 탄화수소 가스의 플라즈마 분해에 의해 증착되는 DLC 막은 높은 경도, 화학적 안정성, 높은 전기 저항성, 적외선 영역의 투과성 등의 여러가지 우수한 성질을 지니고 있다. 그러나 이들막은 높은 내부응력으로 인하여 실제 응용에 상당한 제약을 받고 있다. 본 연구에서는 rf PECVD 법에 의해 합성된 다이아몬드상 탄소막을 보조가스 첨가에 따른 영향에 대하여 조사하였다. 수소가스를 첨가하여 합성된 DLC막의 잔류응력 거동은 낮은 이온 에너지 (V$_{b}$ $P^{1}$2/-20Volt/m Torr)에서 최대 잔류응력이 발생되지만, 질소 가스를 첨가시키면 높은 이온(V$_{b}$ P$_{1}$2/->70Volt/m Torr)에너지 영역에서 잔류응력의 감소가 나타났다. 수소 량이 증가하면 ion bombardment와 식각 작용을 하고, 질소의 경우 막의 표면 스퍼터링 현상이 발생되었다. 보조가스 첨가에 따라 S$P^{3}$net work구조의 생성과 소멸의 결합 구조를 형성하여, 보조가스 첨가는 DLC막의 잔류응력 거동에 영향을 미치는 것을 알 수 있었다. 이온 에너지에 따른막의 비저항은 막 합성 공정 조건에 관계없이 $10^{6}$-$10^{7}$ Ωm 의 범위에서 분포하고 있는 것으로 조사되었다. 이는 메탄가스(rf PECVD)로 합성된 DLC막의 비저항과 거의 일치하는 것으로 나타났다.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.10 no.4
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• pp.302-308
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• 2000

Stable amorphous calcium carbonate were synthesized from the serial work for the synthetic conditions such as concentration of solution, reaction temperature, aging time and pH of mother liquor. By using this as a precusor, calcite, aragonite and vaterite crystal particles were obtained in the water from adequate crystallization conditions. Furthermore, characterization for flourescence were performed by using crystals which were crystallized from the Sn dopped amorphous calcium carbonate. Calcite showed the most intensive emission and the center of emission wavelength was 464 nm with pure blue color. Calcite is expected to be used as phosphor for flourescent lamp because the maximum emission intensity was obtained from the excitation with 255 nm wavelength.