• Title/Summary/Keyword: substrates

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A Study on the Distribution Patterns of Salix gracilistyla and Phragmites japonica Communities according to Micro-landforms and Substrates of the Stream Corridor (하천 미지형 및 하상저질에 따른 갯버들과 달뿌리풀군락의 분포특성에 관한 연구)

  • 전승훈;현진이;최정권
    • Journal of the Korean Institute of Landscape Architecture
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    • v.27 no.2
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    • pp.58-68
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    • 1999
  • This study was carried out to verify the distribution patterns of Salix gracilistyla and Phragmites japonica communities known as obligatory riparian species according to physical factors such as micro-landforms, substrates, etc., at Soo-ip stream corridor. Firstly four vegetation types - Salix gracilistyla dominant type, Phragmites japonica dominant type, mixed type of two species, and mixed type of two species to other species, were classified by cluster analysis based on UPGMA-Euclidean distance. Also these vegetation types showed many different distribution patterns in response to the longitudinal and lateral view along the stream corridor and substrate composition. Salix gracilistyla was major component of dominant vegetation types developed at attack point of bending reach and on substrates composed of rock fragments, but contrastly Phragmites japonica was most important component of dominant vegetation types at point bar of bending reach and floodplain, and on substrates composed of soil materials. Secondly the species and environment biplot form CCA strongly supported the vegetation types divided by classification. Namely Salix gracilistyla was closely correlated with rock fragments and steep slope, which is resistant to physical action even though located near running water. But Phragmites japonica showed a high correlation with soil particles sedimented at floodplain by divergent flow.

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Epitaxial growth of oxide films using miscut substrates (Miscut된 기판을 이용할 산화물 박막의 에피 성장)

  • Bu Sang Don
    • Journal of the Korean Vacuum Society
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    • v.13 no.4
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    • pp.145-149
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    • 2004
  • We have grown piezoelectric oxide films by RF magnetron sputtering using miscut substrates. Films were Brown on(001) $SrTiO_3$ substrates with miscut angles from 0 to 8 degrees toward the (100) direction. Films on high miscut substrates (>$4^{\circ}$) showed almost the pure perovskite phase in x-ray diffraction and were nearly stoichiometric. In contrast, films on exact (001) $SrTiO_3$ contained a high volume fraction of pyrochlore phases. A film on an $8^{\circ}$ miscut substrate exhibits a polarization hysteresis loop with a remnent polarization of 20$\mu$C/$\textrm{cm}^2$ at room temperature.

The Fabrication of Hydroxyapatite Targets and the Characteristics of Hydroxyapatite/Ti-6Al-4V Alloy Thin Films by RF Sputtering(I) (RF 스퍼터링용 Hydroxyapatite 타겟의 제조 및 Hydroxyapatite/Ti-6Al-4V 합금 박막의 특성(I))

  • Jung, Chan-Hoi;Kim, Myung-Han
    • Korean Journal of Materials Research
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    • v.13 no.4
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    • pp.205-212
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    • 2003
  • RF sputtering process was applied to produce thin hydroxyapatite[HA, Ca10($PO_4$)$_{6}$ $ (OH)_2$films on Ti-6Al-4V alloy substrates. To make a 101.6 mm dia.${\times}$5 mm HA target, the commercial HA powder was first calcinated for 3h at $200^{\circ}C$. A certain amount of the calcinated HA powder was pressed under a pressure of 20,000 psi by the cold isostatic press(CIP) and the pressed HA target was sintered for 6 h at $1,200^{\circ}C$. The effects of different heat treating conditions on the bonding strength between HA thin films and Ti-6Al-4V alloy substrates were studied. Before deposition, the alloy substrates were annealed for 1 h at $850^{\circ}C$ under $3.0${\times}$10^{-3}$ Xtorr, and after deposition, the hydroxyapatite/Ti-6Al-4V alloy thin films were annealed for 1 h at 400, 600 and $800^{\circ}C$ under the atmosphere, respectively. Experimental results represented that the HA thin films on the annealed substrates had higher hardness than non-heat treated substrates before the deposition.

GaAs Epilayer Growth on Si(100) Substrates Cleaned by As/Ga Beam and Its RHEED Patterns (As과 Ga 빔 조사에 의해 세척된 Si(100) 기판 위에 GaAs 에피층 성장과 RHEED 패턴)

  • Yim, Kwang-Gug;Kim, Min-Su;Leem, Jae-Young
    • Journal of the Korean institute of surface engineering
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    • v.43 no.4
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    • pp.170-175
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    • 2010
  • The GaAs epitaxial layers were grown on Si(100) substrates by molecular beam epitaxy(MBE) using the two-step method. The Si(100) substrates were cleaned with different surface cleaning method of vacuum heating, As-beam, and Ga-beam at the substrate temperature of $800^{\circ}C$. Growth temperature and thickness of the GaAs epitaxial layer were $800^{\circ}C$ and 1 ${\mu}m$, respectively. The surface structure and epitaxial growth were observed by reflection high-energy electron diffraction(RHEED) and scanning electron microscope(SEM). Just surface structure of the Si(100) substrate cleaned by Ga-beam at $800^{\circ}C$ shows double domain ($2{\times}1$). RHEED patterns of the GaAs epitaxial layers grown on Si(100) substrates with cleaning method of vacuum heating, As-beam, and Ga-beam show spot-like, ($2{\times}4$) with spot, and clear ($2{\times}4$). From SEM, it is found that the GaAs epitaxial layers grown on Si(100) substrates with Ga-beam cleaning has a high quality.

Effect of Gold Substrates on the Raman Spectra of Graphene

  • Kim, Na-Young;Oh, Min-Kyung;Park, Sung-Ho;Kim, Seong-Kyu;Hong, Byung-Hee
    • Bulletin of the Korean Chemical Society
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    • v.31 no.4
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    • pp.999-1003
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    • 2010
  • Raman spectra of a single layer graphene sheet placed in different gold substrates were obtained and are discussed in the context of surface enhanced Raman scattering (SERS). The gold substrates were composed of a combination of a thermally deposited gold film and a close-packed gold nanosphere layer. The SERS effects were negligible when the excitation wavelength was 514 nm, while the Raman signals were enhanced 3-to 50-fold when the excitation wavelength was 633 nm. The large SERS enhancement accompanied a spectral distortion with appearance of several unidentifiable peaks, as well as enhancement of a broadened D peak. These phenomena are interpreted as the local field enhancement in the nanostructure of the gold substrates. The difference in the enhancement factors among the various gold substrates is explained with a model in which the spatial distribution and polarization of the local field and the orientation of the inserted graphene sheet are considered important.

Pepsin Action on the New Synthetic Peptides 1. Pepsin action on benzyloxycarbonyl-glycyl-L-tyrosyl-L-phenylalanyl-glycine and its ethyl ester (새로운 합성 펩티드에 대한 펩신 작용 1. Benzyloxycarbonyl-glycyl-L-tyrosyl-L-phenylalanyl-glycine 과 그의 에틸에스테르에 대한 펩신 작용)

  • Yoon, Joo-Ok;Shin, Hong-Dae
    • Journal of the Korean Chemical Society
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    • v.13 no.3
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    • pp.233-240
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    • 1969
  • The synthesis is described of new pepsin substrates of benzyloxycarbonyl-glycyl-L-tyrosyl-L-phenylalanyl-glycine ethyl ester and benzyloxycarbonyl-glycyl-L-tyrosyl-L-phenylalanyl-glycine for studies on the specificity of pepsin, and thin layer chromatographic examination of the peptides prepared showed the new substrates are homogeneous and also, same examination of the incubation mixtures showed that two synthetic substrates are cleaved by pepsin at the L-tyrosyl-L-phenylalanyl bond and hydrolysis of these substrates by pepsin is achieved without transpeptidation. It is found that synthetic peptides are moderately soluble with the amount of the substrate up to a concentration of 0.7 mM in aqueous sodium citrate buffers (0.04 M) in the pH range 1.8-4.0, thus obviating the necessity for the adding of an organic solvent in the assay mixture. The kinetic parameters for synthetic substrates are tabulated in the following table. The data in the table indicate that the susceptibility of synthetic peptides to peptic hydrolysis are relatively large and the change of the carboxyl-terminal group of synthetic substrate from glycine ethyl ester to glycine causes a small decrease in the susceptibility of the L-tyrosyl-L-phenylalanyl bond.

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The Blanket Deposition and the Sputter Seeding Effects on Substrates of the Chemically Vapor Deposited Cu Films (Sputter Seeding을 이용한 CVD Cu 박막의 비선택적 증착 및 기판의 영향)

  • Park, Jong-Man;Kim, Seok;Choi, Doo-Jin;Ko, Dae-Hong
    • Journal of the Korean Ceramic Society
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    • v.35 no.8
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    • pp.827-835
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    • 1998
  • Blanket Copper films were chemically vapor deposited on six kinds for substrates for scrutinizing the change of characteristics induced by the difference of substrates and seeding layers. Both TiN/Si and {{{{ { SiO}_{2 } }}/Si wafers were used as-recevied and with the Cu-seeding layers of 40${\AA}$ and 160${\AA}$ which were produced by sputtering The CVD processes were exectued at the deposition temperatures between 130$^{\circ}C$ and 260$^{\circ}C$ us-ing (hfc)Cu(VTMS) as a precursor. The deposition rate of 40$^{\circ}C$ Cu-seeded substrates was higher than that of other substrates and especially in seeded {{{{ { SiO}_{2 } }}/Si substrate because of the incubation period reducing in-duced by seeding layer at the same deposition time and temperature. The resistivity of 160${\AA}$ Cu seeded substrate was lower then that of 40 ${\AA}$ because the nucleation and growth behavior in Cu-island is different from the behavior in {{{{ { SiO}_{2 } }} substrate due to the dielectricity of {{{{ { SiO}_{2 } }}.

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Design and Analysis of Optical Properties of Anti-reflection Coated ZnS Substrates in the Mid-infrared Region (중적외선 영역의 무반사 코팅된 ZnS 기판의 설계와 광학 특성)

  • Park, Buem Keun;Paik, Jong-Hoo
    • Journal of Sensor Science and Technology
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    • v.31 no.4
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    • pp.255-259
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    • 2022
  • In this study, we fabricated ZnS substrates with excellent transmittance in the mid-infrared region (3-5 ㎛) using hot pressing instead of conventional chemical vapor deposition (CVD). Diamond-like carbon (DLC) was coated on either one or both sides of the ZnS substrates to improve their mechanical properties and transmittance efficiency. To reduce the reflectance and further improve transmittance in the mid-infrared region, anti-reflection (AR) coating was designed for DLC/ZnS /AR and AR/ ZnS /AR structures. The coating structure, microstructure, and optical properties of the AR-coated ZnS substrates were subsequently investigated by employing energy dispersive X-ray spectroscopy, scanning electron microscopy, and Fourier-transform infrared (FTIR) spectroscopy. The FTIR spectroscopy results demonstrated that, in the mid-infrared region, the average transmittance of the samples with AR coating on one and both sides increased by approximately 18% and 27%, respectively. Thus, AR coating improved the transmittance of the ZnS substrates.

The effect of environmental condition to the mycelial browning of Lentinula edodes (Berkeley) Sing. during sawdust bag cultivation (환경조건이 표고톱밥배지의 갈변에 미치는 영향)

  • Kim, Young-Ho;Jhune, Chang-Sung;Park, Soo-Chul;You, Chang-Hyun;Sung, Jae-Mo;Kong, Won-Sik
    • Journal of Mushroom
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    • v.7 no.3
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    • pp.115-121
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    • 2009
  • Recently sawdust cultivation of Shiitake mushroom (Lentinula edodes ) is getting increased because log cultivation is getting difficult to get oak logs. It is important to make mycelia browning on the substrate surface in sawdust cultivation. This browned surface plays an important role like as artificial bark of the oak log, which protects the other pests and suppresses water evaporation in the substrate. The period for mycelia browning is so long that the sawdust cultivation of Shiitake mushroom can not spread well into the mushroom farms. In this article we would like to discuss about the effect of environmental condition to the mycelial browning during sawdust bag cultivation for the To reduce the period required for browning of substrates, sawdust substrates was illuminated light with difference intensity. One hundred Lux light illumination was needed for producing normal yield of fruit body but fruit body yield was low and abnormally shaped fruit body was produced when cultured under the dark condition of incubation. Illumination over 200lux is necessary for the successful browning of substrates during incubation. Optimum incubation temperature for browning of substrates and fruiting was $25^{\circ}C$. The treatment of cotton plug with different size to identify the effect of aeration on the browning of substrates and fruiting showed rapid mycelial growth and reduced the periods for browning as the size of cotton plug was bigger. However, yield of fruit body was the highest at 16mm diameter cotton plug as compared to 20mm of that. $CO_2$ content in vessel of substrates was low as the size of cotton plug was bigger during incubation. $CO_2$ content during incubation of substrate was highest in periods between 8 week and 14 week after inoculation of shiitake when substrate was changed color into brown. $C_2H_4$ content in vessel with substrates was highest at 8mm diameter cotton plug and it was increased by order of 12, 16, 20, 0, 4 mm diameter cotton plug during substrate incubation. Sawdust substrate was soaked in cold water for different time to identify soaking effect of sawdust substrate on fruit body yield and activities of enzymes in these substrates were investigated. The fruit body yield was increased up to 40% by soaking substrates in comparison with unsoaked substrates. The soaked substrates showed 165, 175g/1,000ml at treatment of 4 and 15 hours, respectively. Cellulose activities in soaked substrates were not changed with soaking time, but activities of laccase, lignin degradation enzyme, were drastically increased up to 4 times in comparison with unsoaked substrates.

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Barix Thin Film Encapsulation of OLED's on Flexible and Rigid Glass substrates; high temperature performance and manufacturing aspects.

  • Chu, X.;Moro, L.;Rutherford, N.;Visser, R.J.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08b
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    • pp.1699-1702
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    • 2007
  • We will discuss encapsulation of OLEDs on both flexible and rigid glass substrates. Accelerated testing at 6CC/90RH and 85C/85RH is compared and acceleration factors for OLED and Calcium test samples are discussed.We have tested the stability and performance of our barrier coating to much higher temperatures: up to 140 C. Water Vapor Transmission rates at temperatures from 60 to 140 C are presented. Rates and methods for low cost manufacturing on a large scale are analysed

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