• 제목/요약/키워드: white crystals

검색결과 47건 처리시간 0.027초

Fast Response Time in IPS Mode Using LC mixtures with High Elastic Constant

  • Lim, C.S.;Lee, J.H.;Choi, H.C.;Oh, C.H.;Yeo, S.D.;Lee, Seung-Eun;Jin, Min-Ok;Kang, Doo-Jin;Klasen-Memmer, M.;Tarumi, K.
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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    • pp.843-846
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    • 2004
  • For the fast growing Liquid Crystal Display (LCD) TV market, it is essential to make the LCD panels to show moving images without any visual difficulties such as blurring or tailing. Owing to reduction of the cell gap and the improved Liquid Crystal (LC) mixtures with low viscosity, it is possible that our S-IPS TFT-LCDs feature a response time (R/T) as fast as 1-frame time (16ms) for a white-black operation and less than a 16rns in all gray levels without Over Driving Circuit (ODC) technology. Currently, mass production of the large size IPS panels with high speed has been successfully achieved. In order to achieve faster response time, new LC mixtures have been developed, optimizing the physical properties of rotational viscosity (${\gamma}$1) and elastic constants (Kii). Also, the LC mixtures with high elastic constant allow us to increase the cell gap. In this paper, realization of fast switching time in IPS mode with optimized '${\gamma}$1/Kii' parameter in the LC mixtures forms the core of this paper.

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희토류 첨가 광소재의 나노구조 : Dy 첨가 Ge-As-S 유리의 X-선 흡수 스펙트럼 분석 (Nanostructure of Optical Materials Doped with Rare-Earths: X-Ray Absorption Spectroscopy of Dy-Doped Ge-As-S Glass)

  • 최용규;송재혁;신용범;;허종
    • 한국세라믹학회지
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    • 제43권3호
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    • pp.177-184
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    • 2006
  • Dy $L_3$-edge XANES and EXAFS spectra of chalcogenide Ge-As-S glass doped with ca. 0.2 wt% dysprosium have been investigated along with some reference Dy-containing crystals. Amplitude of the white-line peak in XANES spectrum of the glass sample turns out to be stronger than that of other reference crystals, i.e., $DY_2S_3,\;Dy_2O_3\;and\;DyBr_3$. It has been verified from the Dy $L_3$-edge EXAFS spectra that a central Dy atom is surrounded by $6.7{\pm}0.5$ sulfur atoms in its first coordination shell in the Ge-As-S glass, which is relatively smaller than 7.5 of the $Dy_2S_3$ crystal. Averaged Dy-S inter-atomic-distance of the glass ($2.78{\pm}0.01{\AA}$) also turns out to be somewhat shorter than that of the $Dy_2S_3$ crystal ($2.82{\pm}0.01{\AA}$). Such nanostructural changes occurring at Dy atoms imply there being stronger covalency of Dy-S chemical bonds in the Ge-As-S glass than in the crystal counterpart. The enhanced covalency in the nanostructural environment of $Dy^{3+}$ ions inside the glass would then be responsible for optical characteristics of the $4f{\leftrightarrow}4f$ transitions of the dopants, i.e., increase of oscillator strengths and spontaneous radiative transition probabilities.

천연칼슘소재로서 개조개(Saxidomus purpuratus)와 바지락(Ruditapes philippinarum) 패각 및 소성분말의 특성 (Characteristics of the Shells and Calcined Powders from the Butter Clam Saxidomus purpuratus and Littleneck Clam Ruditapes philippinarum as a Natural Calcium Resource)

  • 김진수;정남영;장수정;이현지;박성환;김민주;허민수
    • 한국수산과학회지
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    • 제48권2호
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    • pp.168-177
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    • 2015
  • Shell waste from the butter clam Saxidomus purpuratus and littleneck clam Ruditapes philippinarum is a large by-product of shellfish aquaculture, and it is desirable to convert it into value-added products for industrial applications. In this study, calcium carbonate (CaC) polymorphs from butter clam (BCSP) and littleneck clam (LCSP) shell powders and commercial CaC were characterized using Fourier transmission infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The results revealed that the optimal calcination conditions to eliminate organic substances and improve solubility for both BCSP and LCSP were $800^{\circ}C$ for 8 h in an electrical furnace. Calcination improved the white index of the butter clam (BCCP) and littleneck clam (LCCP) calcined powder compared with shell powders. The calcium content in BCCP (51.1%) was higher than that of LCCP (44.9%) or commercial calcium oxide (CaO, 44.7%). The XRD patterns of BCCP and LCCP were similar to that of CaO. Cubic-like crystals of CaC and irregular crystals of BCCP and LCCP were observed by SEM. The FT-IR and XRD analyses revealed the presence of calcite and aragonite in the BCSP and aragonite in the LCSP, whereas the CaC contained calcite. These results indicate that butter and littleneck clam shells are potential biomass resources for calcium carbonate and calcium oxide.

KTP 크리스탈을 이용한 PDT용 레이저 시스템 개발 (A Study on a KTP Crystal Laser System for a Cancer Using P.D.T.)

  • 김병문;남효덕;김병철
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.2
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    • pp.631-634
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    • 2004
  • The method that exists in Photodynamic Therapy uses Photosensibility drug strongly Influencing tumour accumulation together with photochemical laser effect and makes the structure of tumour be localized and become extinct. The intracavity transformation of the Nd :YAP main radiation 1079 nm was Raman converted in barium nitrate crystal and the Stokes frequency (1216 nm) was doubled using KTP or RTA crystals. The LiF or Cr:YAG crystals are used for the Q-switch. The radiation Parameters were obtained at 100 Hz pump repetition frequency. The average power at 608 nm radiation with LiF and KTP was 700 mW at multi-mode generation. The 3-6 single 10-15 ns pulses were generated during one cycle of pumping. The doubling efficiency with RTA was two times more than with KTP. The cells of Ehrlich adenocarcinoma (0.1 ml) were i.m. implanted in hind thighs of ICR white non-imbred mice. The cells were preliminarily diluted in medium 199 in the ratio of 1 to 5. HpD was intravenous administered in a dose of 10 mg/kg. The left clean-shaven hind leg was irradiated with laser light 21-27 hours after the administration of the preparation. The right non-Irradiated leg of each animal served as a control. The animals with the transplanted tumor that were not injected with HpD sewed as a control to estimate the complex effect (HpD+ irradiation). Before the administration of HpD and on 3 and 4 days after irradiation the tumor size was measured and the percent of the tumor growth inhibition was calculated. The results of animal treatments has shown high efficiency of PDT method for cancer treatment by means 0.608 m high power pulse solid state laser.

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(-201)면 산화갈륨 단결정 기판 미세 결함 분석 (Characterizations of Microscopic Defect Distribution on (-201) Ga2O3 Single Crystal Substrates)

  • 최미희;신윤지;조성호;정운현;정성민;배시영
    • 한국전기전자재료학회논문지
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    • 제35권5호
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    • pp.504-508
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    • 2022
  • Single crystal gallium oxide (Ga2O3) has been an emerging material for power semiconductor applications. However, the defect distribution of Ga2O3 substrates needs to be carefully characterized to improve crystal quality during crystal growth. We analyzed the type and the distribution of defects on commercial (-201) Ga2O3 substrates to get a basic standard prior to growing Ga2O3 crystals. Etch pit technique was employed to expose the type of defects on the Ga2O3 substrates. Synchrotron white beam X-ray topography was also utilized to observe the defect distribution by a nondestructive manner. We expect that the observation of defect distribution with three-dimensional geometry will also be useful for other crystal planes of Ga2O3 single crystals.

Study on the Preferred Orientation Using White Neutron

  • Lee, Yun-Peel
    • Nuclear Engineering and Technology
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    • 제6권4호
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    • pp.219-230
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    • 1974
  • 강한 방향성이 있는 다결정에 의한 중성자회절강도에 대한 재래의 공식을 결정의 반사율에 관한 Kunitomi 의식을 사용하여 수정하였다. 시료내의 grain 에서 회절이 일어나는 정화한 위치가 회절강도의 Maxwell곡선의 소각부분에 관한 이론치와 계산치를 비교함으로써 발견된다는 사실과 위의 회절강도 공식을 사용하여 금속내의 Preferred orientation을 백색중성자를 가지고 조사한 수 있는 방법을 고안하였다. 결정 내에서 일어나는 중성자비 다중반사와 흡수에 대해서 교정하여 원자로의 중성자 스펙트럼을 측정함으로써 열중성자의 확실성있는 파장이 1.025$\pm$0.001$\AA$임을 알았다. 대부분 cube-on-face 방향을 갖인 씰리콘 강철을 본 연구방법으로 조사차였는바 grain들이 압연방향에서 5도 이내에 배열되어 있다는 사실을 발견하였다. 커다란 결정에 적합한 이론들이 강한 방향성이 있는 다결정 물체에도 적응될 수 있음을 알게 되었다.

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화력발전소 바닥재로 제조된 결정화 유리의 미세구조 (Microstructure of Glass-ceramics Made from Bottom Ash Produced at a Thermal Power Plant)

  • 강승구
    • 한국재료학회지
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    • 제19권2호
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    • pp.95-101
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    • 2009
  • Glass ceramics were made from coal bottom ash by adding CaO and $Li_2O$ as glass modifiers and $TiO_2$ as a nucleating agent in a process of melting and quenching followed by a thermal treatment. The surface of the glass ceramics has 1.6 times more $Li_2O$ compared to the inner matrix. When $TiO_2$ was not added or when only 2 wt% was added, the surface parts of the glass ceramics were crystalline with a thickness close to $130{\mu}m$. In addition, the matrixes showed only the glass phase and not the crystalline phase. However, doping of $TiO_2$ from 4 wt% to 10 wt% began to create small crystalline phases in the matrix with an increase in the quantity of the crystalline. The matrix microstructure of glass ceramics containing $TiO_2$ in excess of 8 wt% was a mixture of dark-gray crystalline and white crystalline parts. These two parts had no considerable difference in terms of composition. It was thought that the crystallization mechanism affects the crystal growth, direction and shape and rather than the existence of two types of crystals.

엘크의 폐장 아스퍼질러스증 및 신장 옥살산증 (Pulmonary Aspergillosis and Renal Oxalosis in an Elk)

  • 김재훈;강경일;김원일;손현주;이상경;진영화
    • 대한수의학회지
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    • 제42권3호
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    • pp.383-387
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    • 2002
  • A four-year-old male elk (Cervus elaphus nelsoni) was diagnosed as pulmonary aspergillosis and renal oxalosis. Clinical signs were coughing, sneezing, respiratory distress, salivation, moderate anorexia, and progressive emaciation. Main gross lesions were fibrinopurulent tonsillitis, diffusely fibrinous pleuritis, and distinct lobar pneumonia with purple red in color. Most of the pulmonary lobes had numerous well demarcated 0.5 to 2 cm yellowish white discrete or confluent nodules that were surrounded by pale red zones. Histopathologically, the affected lungs were disseminated necrotizing pyogranulomas including fungal hypae, vasculitis, and diffusely fibronecrotic pleuritis. The renal lesions were composed of extensive tubular necrosis with large numbers of rosette-formation by birefringent oxalate crystals. Aspergillus fumigatus was isolated from lesions of the lungs. It seems to be a first report for pulmonary aspergillalis and renal oxalosis of a farmed elk in Korea.

언양 자수정 형성 환경의 압력-온도-성분에 대한 유체포유물의 이용 (The use of fluid inclusions to constrain P-T-X conditions of formation of Eonyang amethyst)

  • K. H. Yang
    • 암석학회지
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    • 제5권1호
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    • pp.1-9
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    • 1996
  • Eonyang amethyst deposits are thought to be spatially and temporally associated with the biotite granite of the Kyeongsang Basin. The examined euhedral quartz crystals in cavities in the aplite intruded biotite granite are colored-zoned from white at the base to amethystine at the tops. Three types of primary Inclusions were observed and three is representing each types are constructed to constrain the trapping conditions and fluid evolution involved during the formation of the amethyst. The intersection of the isochore representing the early fluid inclusions with solidus temperature of the host granite indicates initial quartz formation at about $600^{\circ}C$ and 1.0-1.5 kbars . Intermediate quartz formation, associated with the high-salinity inclusions, occurred at somewhat lower temperatures ($400^{circ}c$) and pressures of about 1 kbar. The amethystine quartz formed from $H_2O$-$CO_2$-NaCl fluids at temperatures between 280-$400^{circ}c$ and pressures of about 1 kbar. Early quartz is interpreted to have formed from fluids that either exsolved from or were in equilibrium with the granite at near solidus conditions, whereas the amethystine quartz apparently grew from fluids of at least partial sedimentary origin.

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Control Efficacy of Milk Concentration Against Powdery Mildew of Strawberry

  • Nam, Myeong-Hyeon;Lee, Won-Keun;Lee, Sok-Su;Kim, Nam-Gyu;Kim, Hong-Gi
    • The Plant Pathology Journal
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    • 제21권3호
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    • pp.270-274
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    • 2005
  • The aim of this study was to determine the effect of milk as one of the environmental friendly materials that substitute chemical fungicides for control powdery mildew (Sphaerotheca aphanis) of strawberries $(Fragaria{\times}ananassa\;Duch.)$. 'Maehyang' and 'Akihime' varieties planted in greenhouses were evaluated for the control of powdery mildew. Applications of $5\%,\;10\%\;and\;20\%$ milk had much better effects on controlling powdery mildew. In particular, $10\%$ milk showed a higher efficacy than other concentrations applied onto straw­berry in greenhouse experiments. Foliar spray application of $10\%$ milk was effective for powdery mildew, whereas drench application was not. Also, foliar spray of $10\%$ milk was able to accelerate more firmness and calcium contents of strawberry fruits than the non-treated. The $10\%$ milk applied with fertilizer salts $(Ca(H_2PO_4)_2-H_2O\;and KH_2PO_4)$ showed there was a similar efficacy to $10\%$ milk alone in greenhouse experiments. White crystals and cracks on strawberry fruits appeared by $20\%$ milk. This result indicated that $10\%$ milk was a useful substitute for fungicides to control powdery mildew of strawberry.