• 제목/요약/키워드: Seed structure

검색결과 385건 처리시간 0.031초

SBN 박막의 결정화 및 전기적 특성에 관한 씨앗층 두께의 영향 (Effect of Seed-layer thickness on the Crystallization and Electric Properties of SBN Thin Films.)

  • 장재훈;이동근;이희영;조상희
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2003년도 추계학술대회 논문집 Vol.16
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    • pp.271-274
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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 films of different thickness were pre-deposited as a seed layer on $Pt(100)/TiO_2/SiO_2/Si$ substrate followed by SBN60 deposition up to $4500\;{\AA}$ 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 difference in the crystal structure with heat-treatment temperature, and the electric properties depended on the heating temperature and the seed-layer thickness. 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) 65 kV/cm, and the dielectric constant 1492, respectively.

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인삼(Panax ginseng C.A. Meyer)의 종자형성에 있어서 배유세포의 미세구조의 변화 및 저장물질의 형성 (Ultrastructural Changes and Formation of Storage Materials in Endosperm Cells during the Seed Formation of Panax ginseng C.A. Meyer)

  • 유성철
    • Journal of Plant Biology
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    • 제34권3호
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    • pp.201-213
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    • 1991
  • This study has been carried out to investigate the ultrastructural changes, formation of storage materials in endosperm cells with electron microscope during the seed formation of Panax ginseng C.A. Meyer. In the early stage of seed formation with green seed coat, the endosperm was cellular type. Cell plate was largely composed of dictyosome vesicles in early stage of wall formation after mitosis. Central vacuole was gradually subdivided into several small-sized vacuoles. During the differentiation of plastids, some proplastid was replaced by amyloplast with starch grains and lamellar structure. A number of mitochondria with well developed cristae were distributed in cytoplasm. Rough endoplasmc reticulum, dictyosome, microbody, free ribosomes and polysomes were evenly distributed in cytoplasm. Spherical spherosomes were formed from dictyosome containing the lipid materials of even electron density. Protein bodies were formed by interfusing between vacuoles and vesicles derived from rough endoplasmic reticulum which contained the amorphous protein of high electron density.

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Contrasting rice sub-populations to tocols ratio associated with seed longevity

  • Lee, Jae-Sung;Kwak, Jieun;Yoon, Mi-Ra;Lee, Jeom-Sig;Hay, Fiona R.
    • 한국작물학회:학술대회논문집
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    • 한국작물학회 2017년도 9th Asian Crop Science Association conference
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    • pp.31-31
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    • 2017
  • Understanding the mechanism(s) to overcome or prevent seed ageing deterioration during storage is of fundamental interest to seed physiologists. Vitamin E (tocols) is known as a key metabolite to efficiently scavenge lipid peroxy radicals which cause membrane breakdown resulting in seed ageing. However, in rice research this hypothesis has been tested for very few lines only without considering intraspecific variation in genomic structure. Here, we present a correlation study between tocols and seed longevity using a diverse rice panel. Seeds of 20 rice accessions held in the International Rice Genebank at the International Rice Research Institute, representing aus, indica, temperate japonica and tropical japonica subpopulations, were used for tocols analysis (quantification of ${\alpha}$-, ${\beta}$-, ${\gamma}$-, ${\delta}$-tocopherol/tocotrienol by ultra performance liquid chromatography) and storage experiments at $45^{\circ}C$ and 10.9% seed moisture content (sample taken for germination testing every 3 days up to 60 days). To examine interactions between DNA sequences and phenotype, the 700k high-density single-nucleotide polymorphism marker data-set was utilized. Both seed longevity (time for viability to fall to 50%; $p_{50}$) and tocols content varied across subpopulations due to heterogeneity in the genetic architecture. Among eight types of tocol homologues, ${\alpha}$-tocopherol and ${\gamma}$-tocotrienol were significantly correlated with $p_{50}$ (negatively and positively, respectively). While temperate japonica varieties were most abundant in ${\alpha}$-tocopherol, indica varieties recorded 1.3 to 1.7-fold higher ${\gamma}$-tocotrienol than those of other subpopulations. It was highlighted that specific ratio of tocol homologues rather than total tocols content plays an important role in the seed longevity mechanism.

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Gibberellin 처리가 종서의 당함량 및 붕아경의 생장구조에 미치는 영향 (The variation of Sugar and Sprouting stem in Gibberellin Treated seed potato)

  • 김종진
    • 한국작물학회지
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    • 제8권1호
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    • pp.99-103
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    • 1970
  • Gibberellin을 Seed Potato에 처리함으로서 seed potato내의 환원당과 비환원당의 소장과 붕아경의 현미경적인 조직의 변화에 대한 몇가지 실험결과를 요약하면 다음과 같다. 1) Gibberellin을 처리한 Seed potato에 함유한 환원당은 처리하지 않은 Seed Potato에 비하여 현저히 증가하였으며 그 증가정도는 붕아일수의 경과에 따라 차가 심하였다. 처리농도에 있어서는 10ppm구가 5ppm구 보다 증가하였으나 파종 14일부터는 반대의 경향을 인정할 수 있었다. 2) Gibberellin을 처리한 Seed Potato에 함유한 비환원당의 소장도 환원당과 동일한 경향임을 인정할 수 있었다. 3) 붕아경은 Gibberllin 5ppm 및 10ppm 구 공히 Control에 비하여 신장이 빨랐으며 14일후에는 10ppm 구는 Gibberellin처리에 의한 도장현상으로 약간의 생육장해가 발생하였다. 4) Gibberellin 처리에 의하여 붕아된 붕아경은 종단 및 횡단세포가 현저히 커졌으며 피시부나 중심부가 균등하게 팽대하였고 10ppm구가 더 커졌음을 인정할 수 있었다.

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Au Catalyst Free and Effect of Ga-doped ZnO Seed Layer on Structural Properties of ZnO Nanowire Arrays

  • Yer, In-Hyung;Roh, Ji-Hyoung;Shin, Ju-Hong;Park, Jae-Ho;Jo, Seul-Ki;Park, On-Jeon;Moon, Byung-Moo
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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    • pp.354-354
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    • 2012
  • In this study, we report the vertically aligned ZnO nanowires by using different type of Ga-doped ZnO (GZO) thin films as seed layers to investigate how the underlying GZO film micro structure affects the distribution of ZnO nanowires. Arrays of highly ordered ZnO nanowires have been synthesized on GZO thin film seed layer prepared on p-Si substrates ($7-13{\Omega}cm$) with utilize of a pulsed laser deposition (PLD). With the vapor-liquid-solid (VLS) growth process, the ZnO nanowire synthesis carries out no metal catalyst and is cost-effective; furthermore, The GZO seed layer facilitates the uniform growth of well-aligned ZnO nanowires. The influence of the growth temperature and various thickness of GZO seed layer have been analyzed. Crystallinity of grown seed layer was studied by X-Ray diffraction (XRD); diameter and morphology of ZnO nanowires on seed layer were investigated by field emission scanning electron microscopy (FE-SEM). Our results suggest that the GZO seed layer with high c-axis orientation, good crystallinity, and less lattice mismatch is key parameters to optimize the growth of well-aligned ZnO nanowire arrays.

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차전자(Plantago ovata Forsk)피를 이용하여 제조한 구운 쌀 도넛의 품질 특성 및 노화 특성 (Quality Characteristics and Retrogradation Properties of Baked Rice Donut with Psyllium (Plantago ovata Forsk) Seed Husk)

  • 신소연;오현빈;정기영;김영순
    • 한국식품영양학회지
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    • 제31권3호
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    • pp.367-377
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    • 2018
  • In this study, baked rice donuts with added psyllium seed husk were manufactured and their quality and retrogradation characteristics were investigated. Control (Con) was made only with wheat flour; Psyllium seed husk in the amount of 8, 12, 16 and 20 grams was added to make rice donuts (P8, P12, P16 and P20). Higher amounts of psyllium seed husk reduced the moisture loss and baking loss, and increased the moisture content and water holding capacity of the donuts. The specific volume of Con was the highest of all the groups. As the amount of psyllium seed husk increased, the lightness and yellowness of the crumb decreased, and the redness of the crumb increased. Hardness also increased as the amount of psyllium seed husk increased. The hardness of P16 was the most similar to that of Con. The scanning electron microscopy images also identified that the structure of the donuts got denser as the amount of psyllium seed husk increased. Rate constant (k) of the rice donuts with psyllium seed husk were lower than that of Con. In conclusion, it is considered that P16 is the sample that is the most similar to Con in terms of texture, but the retrogradation was more retarded in P16 than Con.

SEED암호에서 S-함수에 대한 고찰 (A Study on S-Function in SEED Cryptosystem)

  • 양정모
    • 정보보호학회논문지
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    • 제27권6호
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    • pp.1295-1305
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    • 2017
  • 국내 블록암호표준(안)으로는 SEED암호가 있다. 이 암호는 한국정보보호진흥원(KISA)이 1998년 10월에 초안을 설계하고 같은 해 12월에 공개검증과정을 거쳐 안전성과 성능이 개선된 최종 수정안을 발표하였다. DES와는 달리 128비트 블록암호로서 여러 과정을 거쳐 2005년에 국제표준으로 확정되었다. DES와 같은 페이스텔 구조를 가진 블록암호로서 다만 입력비트블록이 DES의 두 배인 128비트로 늘어났다는 것이다. 본 논문에서는 첫째, SEED 암호의 일반적인 알고리즘을 소개하고 F-함수에서 적용되는 열쇠 값의 생성원리를 수학적으로 분석해 보았다. 둘째, S-함수의 8비트 입력 값에 대응되는 원시원소 ${\alpha}$ 의 멱승 값을 계산하는 표를 도출해 보았으며 마지막으로 G-함수 내에 설계되어져 있는 S-함수의 계산 원리를 수학적인 방법으로 새로운 정리와 예제를 통해 분석해 보는 것으로 한정하였다. 이러한 과정을 통하여 현재 알려져 있는 SEED암호의 취약점을 보완할 수 있는 새로운 암호체계를 개발하는데 필요한 아이디어와 이론적인 근거를 제공하는 데 어느 정도 도움이 되고자 한다.

광쌍안정을 갖는 GaAs/AlGaAs MQW 도파로형 위상 광변조기 (GaAs/AlGaAs MQW waveguide phase modulator with optical bistability)

    • 한국광학회지
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    • 제7권3호
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    • pp.280-286
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    • 1996
  • 본 논문에서는 자기 전광 효과를 이용하여 광쌍안정을 갖는 새로운 형태의 도파로형 광변조기의 동작 특성에 관하여 논하였다. 제작된 소자는 전계의 세기에 따른 굴절률의 변화를 이용하는 위상 변조형 광변조기와 전기적 쌍안정성을 갖는 수광 소자가 병렬로 연결된 구조로 되어 있다. 광도파로층과 수광 소자의 흡수층은 GaAs/AlGaAs 다중 양자 우물층을 사용하였다. 수광 소자에 흡수되는 광의 세기에 따라 변하는 다이오드 전압은 도파로형 광변조기를 통과하는 광의 세기를 조절하며 SEED의 전기적 쌍안정을 이용하여 도파로형 광변조기의 광쌍안정을 얻을 수 있었다. 본 논문에서 제안된 광변조기는 기존의 도파로형 광변조기에 비해 낮은 입력광에서도 광안쌍정을 갖는 장점을 갖는다.

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감광성 폴리이미드를 모울드로 이용한 기반층이 없는 선택적 금속 도금에 관한 기초 연구 (A Fundamental Study of Selective Metal Electroplating Without Seed Layers Using a Photosensitive Polyimide as Molds)

  • 안동섭;이상욱;김호성;김용권
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1993년도 정기총회 및 추계학술대회 논문집 학회본부
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    • pp.204-206
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    • 1993
  • In this paper we represented electroplating process without seed layers for making metal micro structures needed for applying terminal voltage for one-to-one cell fusion system. In this system, we need thick insulator and metal structures because the diameter of a cell is approximately $40{\mu}m$. So, we adopted the photo-sensitive polyimide as electroplating molds and structural material. Generally, the processes utilizing the photo-sensitive polyimide as molds have metal seed layers on the substrate as electroplating electrodes and requires wiring tasks to these seed layers. We proposed electroplating process without any seed layer on the Si-substrate and simulated P-N-P (electrode - Si substrate - electrode) junction on N-type silicon substrate. Leakage current from one metal structure to another which arise when terminal voltage is applied can be remarkably decreased by doping Boron in the region to be electroplated.

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Effect of Processing Method on Change of Water Soluble Dietary Fiber of Fagopyrum tataricum

  • Kim, Dong-Eun;Lee, Beom-Goo;Park, Cheol-Ho;Kang, Wie-Soo
    • Agricultural and Biosystems Engineering
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    • 제6권2호
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    • pp.70-76
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    • 2005
  • Seed, stem and sprout of F. tataricum were separately milled using the ultra fine mill under the same condition to investigate the effect of roasting or extruding on the particle size, microstructure and water solubility of dietary fiber. The mean particle size of MR (roasting) is increased in stem and sprout, and that of ME (extruding) is increased in seed, compared to that of control. The microscopic views of seed show that control has the spherical shape but ME the larger and irregular shape, and those of stem and sprout show that control has the needle like shape but ME more rounded shape. Water solubility index of ME is much higher than that of control or MR in seed, stem and sprout. It shows that seed, stem and sprout are damaged more in extruding than in roasting, and the starch and cell wall structure must be destroyed to change the water insoluble dietary fiber into the water soluble dietary fiber.

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