• Title/Summary/Keyword: Growth interruption

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Study on Growth Optimization of InAs/GaSb Strained-Layer Superlattice Structures by High-Resolution XRD Analysis (고분해능 XRD 분석에 의한 InAs/GaSb 응력초격자 구조의 성장 최적화 연구)

  • Kim, J.O.;Shin, H.W.;Choe, J.W.;Lee, S.J.;Kim, C.S.;Noh, S.K.
    • Journal of the Korean Vacuum Society
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    • v.18 no.4
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    • pp.245-253
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    • 2009
  • For the growth optimization of InAs/GaSb (8/8-ML) strained-layer superlattice (SLS), the structure has been grown under various conditions and modes and characterized by the high-resolution x-ray diffraction (XRD) analysis. In this study, the strain modulation is induced by changing parameters and modes, such as the growth temperature, the ratio of V/III beam-equivalent-pressure (BEP), and the growth interruption (GI), and the strain variation is analyzed by measuring the angle separation of 0th-order satellite peak in XRD patterns. The XRD results reveal that the growth temperature and the V/III(Sb/Ga) ratio are major parameters to change the crystallineity and the strain modulation in SLS structures, respectively. We have observed that the SLS samples with compressive strain prepared in this study are show a transition to tensile strain with decreasing V/III(Sb/Ga) ratio, and the GI process is a sensitive factor giving rise to strain modulation. These results obtained in this study suggest that optimized growth temperature and V/III(Sb/Ga) ratio are $350^{\circ}C$ and 20, respectively, and the appropriate GI time is approximately 3 seconds just before InAs growth that the crystallineity is maximized and the strain relaxation is minimized.

Growth inhibition of human pancreatic cancer cells by CR2945-targeted liposome

  • Yoon, Na-Young;Kim, Jin-Seok
    • Proceedings of the PSK Conference
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    • 2002.10a
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    • pp.416.3-417
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    • 2002
  • Among the promising cancer therapy is targeting of the drug to tumor cells via receptor specific ligands. CR2945, $\beta$-2-( [2-(8-azaspiro [4.5] dec-8-ylcarbony!)-4.6-dimethylphenyl]amino-2-oxoethyl] -(R)-1-naphthalenepropanoic acid. is known to have an inhibitory effect on a gastrin receptor of colorectal cancer cells. As the human pancreatic cancer cells (BxPC-3) express gastrin receptors. interruption of binding of gastrin with gastrin receptor of human pancreatic cancer cells by CR2945 inhibits the growth of human pancreatic cancer cells. (omitted)

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Microstructural development of $Si_3N_4/SiC$ nanocomposites during hot pressing ($Si_3N_4/SiC$ 초미립복합재료의 고온가압소결중의 미세구조변화)

  • 황광택;김창삼;정덕수;오근호
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.6 no.4
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    • pp.552-557
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    • 1996
  • Microstructural development of $Si_3N_4$/20 vol% SiC nanocomposites doped 2 wt% $Al_2O_3$ and 6 wt% $Y_2O_3$ as sintering additives were analyzed by sintering interruption. Density of samples was significantly increased between $1500^{\circ}C$ and $1700^{\circ}C$, and near full density was achieved at $1800^{\circ}C$. Transformation rate from $\alpha-Si_3N_4$ to $\betha-Si_3N_4$ was increased at $1700^{\circ}C$ and $1800^{\circ}C$, and then elongated matrix grains were appeared. Small size SiC particles had suppressive effect on densification rate and transformation of $Si_3N_4$ phase.

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Effects of Interruption Layer for Capillary Rise on Salt Accumulation and Kentucky Bluegrass Poa pratensis Growth in Sand Growing Media over the Reclaimed Saline Soil (임해 간척지에서 모래상토 층에 모세관수 차단 층의 도입이 염류 집적과 켄터 키블루그래스 생육에 미치는 영향)

  • Rahayu, Rahayu;Yang, Geun-Mo;Choi, Joon-Soo
    • Asian Journal of Turfgrass Science
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    • v.24 no.2
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    • pp.106-116
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    • 2010
  • This research was conducted to determine the effect of interruption layer for capillary rise on the sand based growing media when growing Kentucky bluegrass (Poa pratensis L.) on soil reclamation and saline water irrigation. Growing media profile consists of three layers as top soil of 30 cm, 20 cm of the interruption layer for capillary rise and 10 cm of reclaimed paddy soil. Growing media profile was packed in 30 cm diameter column pots. The top soil was a mixture of sand dredged up from Lake Bhunam Tae Ahn, Korea and peat at the ratio of 95:5 by volume. Bottom part of column was covered with plastic net and the pots were soaked into 5 cm depth saline water reservoir with salinity $3-5\;dS\;m^{-1}$. Kentucky bluegrass was established by sod and irrigated using $2\;dS\;m^{-1}$ saline water ($5.7\;mm\;day^{-1}$) in 3 days interval. The results showed that the largest accumulation of salt in the spring with electrical conductivity in saturated extract (ECe) of $5.4\;dS\;m^{-1}$ and sodium absorption ratio (SAR) 34.0 in growing media without the interruption layer for capillary rise and ECe of $4.6\;dS\;m^{-1}$ and SAR 8.24 at growing media using gravel as the interruption layer for capillary rise material. The interruption layer for capillary rise of gravel and coarse sand reduced the accumulation of Na by 16% and 25%, ECe by 7% and 13% in the growing media. Visual quality of Kentucky bluegrass was higher in growing media with the interruption layer for capillary rise of gravel than no interruption layer by 8.3 compared to 7.9 in rates. The interruption layer for capillary rise of gravel and coarse sand enhanced the visual quality by 4.1 and 4.0%, root length by 50 and 38%, and root dry weight by 35 and 17% of Kentucky bluegrass, and reduced the accumulation of Na by 16% and 25%, ECe by 7% and 13% in the growing media.

Night Interruption and Night Temperature Regulate Flower Characteristics in Cymbidium

  • Kim, Yoon-Jin;Park, Chae-Jeong;Rho, Hyung-Min;Kim, Ki-Sun
    • Horticultural Science & Technology
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    • v.30 no.3
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    • pp.236-242
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    • 2012
  • We investigated the influences of night interruption (NI) and night temperature on flowering and flower coloration in Cymbidium. Cymbidium 'Red Fire' and 'Yokihi' were grown under a 9 hours photoperiod (control), a 9 hours photoperiod with NI at a low light intensity (LNI) of 3-7 ${\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, or a 9 hours photoperiod with NI at a high light intensity (HNI) of 120 ${\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ for four hours (22:00-02:00 HR) for 16 weeks during the reproductive growth stage (Experiment 1). Thirty month-old Cymbidium 'Red Fire' plants with initiated flowering buds were placed in four different growth chamber with night temperature set points of 6, 9, 12, or $15^{\circ}C$ for 16 hours (18:00 to 09:00 HR) and a daytime temperature of $25^{\circ}C$ (Experiment 2). In Experiment 1, the numbers of visible buds and flowers increased, and time to flowering decreased in both the LNI and HNI treatments, as compared to the control in both cultivars. Red color in Cymbidium 'Red Fire' increased by both LNI and HNI, as evidenced by an increased $a^*$ in plants grown under these conditions, relative to those grown under the control condition. Number of days to visible buds at 9-$15^{\circ}C$ ranged from 31-34 days, as compared to 39 days at $6^{\circ}C$ in Experiment 2. Although as the temperature increased days to flowering decreased when the plant was grown at $15^{\circ}C$ as compared to 6, 9, or $12^{\circ}C$, the red color ($a^*$) also decreased. The number of flowers and percent flowering increased when the night temperature was maintained higher than $9^{\circ}C$. Therefore, NI treatment and maintaining the night temperature at approximately 9-$12^{\circ}C$ during the winter season after flower spike initiation in the reproductive developmental growth stage improve flower quality and controls flowering time.

Effects of Capillary Rise Interruption Layer on Salt Accumulation and Kentucky Bluegrass (Poapratensis L.) Growth in Sand Growing Media Established Over the Reclaimed Saline Soil (임해 간척지에서 모래상토 층에 모세관수 차단 층의 도입이 염류 집적과 켄터키블루그래스 생육에 미치는 영향)

  • Rahayu, Rahayu;Yang, Geun-Mo;Choi, Joon-Soo
    • Proceedings of the Turfgrass Society of Korea Conference
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    • 2011.02a
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    • pp.5-8
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    • 2011
  • This research was conducted to determine the effect of capillary rise interruption layer on the sand based growing media when growing Kentucky bluegrass under soil reclamation and saline water irrigation. Rootzone profile consists of three layers as top soil of 30 cm, 20 cm of capillary interruption layer and 10 cm of reclaimed paddy soil. Rootzone profile was packed in column pots. The top soil was a mixture of sand dredged up from Lake Bhunam Tae Ahn, Korea and peat at the ratio of 95:5 by volume. Bottom part of column was covered with plastic net and the pots were soaked into 5 cm depth saline water reservoir with salinity $3-5dsm^{-1}$. Kentucky bluegrass was installed by sod and irrigated using $2dSm^{-1}$ saline water(5.7mm $day^{-1}$)in 3days interval. The results showed that the largest accumulation of salt in the spring with ECe of $5.4dSm^{-1}$ and SAR34.0 in rootzone with out capillary rise interruption layer and ECe of $4.6dSm^{-1}$ and SAR8.24 at rootzone using gravel as capillary rise interruption layer material. Kentucky bluegrass grown in growing media with gravel as capillary rise interruption layer resulted in the average visual quality rate of 8.1and clipping dry weight of $24.8gm^{-2}$, while Kentucky bluegrass grown in the growing media with out capillary rise interruption layer showed the visual quality rate of 7.9 and clipping dry weight of $34g.m^{-2}$. Capillary rise interruption layer of gravel and coarses and enhanced the visual quality by 4.1and 4.0%, root length by 50 and 38%, and root dryweight by 35and 17% of Kentucky bluegrass, and reduced the accumulation of Na by 16% and 25%, ECe by 7% and 13% in the rootzone.

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CHARACTERIZATIONS OF TILTED SUPERLATTICE QUANTUM WIRE GROWN BY MIGRATION ENHANCED EPITAXY METHOD

  • Kim, D.W.;Woo, J.C.
    • Journal of the Korean institute of surface engineering
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    • v.29 no.6
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    • pp.753-759
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    • 1996
  • The artificial construction of well-defined low-dimensional (low-D) quantum structures, such as quantum wire (QWR) still attracts attention of many researchers due to their applications in room-temperature optoelectronic devices. In this work, the migration enhanced epitaxial growth (MEE) and the analysis of InAs/ AlAs QWR are reported. On the vicinal semi-insulating InP substrate of $3^o$ tilted cut from (100) surface towards (010) direction, InAs/ AlAs QWR superlattices have been successfully grown by MEE with the introduction of growth interruption at each shutter operation of MBE cell. The in-situ RHEED analyses show that MEE gives superior step-flow growth (SFG) and sharper interface formation over a conventional MBE growth. We have grown 4 samples in series varying the growth temperature. The QWR samples are analyzed by photoluminescence (PL) and atomic force microscopy (AFM). From the AFM images, we can get the definitely resolved 1-D structures. This structure is believed to be due to the MEE method and its separation is better than any other data from others. We are now studying the dependence of the structure on the growth temperature.

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Reliability and Validatity of a Korean version of Posttraumatic Growth Inventory Among Cancer Caregivers (암환자 가족을 대상으로 한 '외상 후 성장 척도(K-PTGI)'의 타당도 검증)

  • Rhee, Young-Sun
    • Korean Journal of Social Welfare Studies
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    • v.40 no.2
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    • pp.123-143
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    • 2009
  • To investigate the reliability, validity of posttraumatic growth among Korean cancer caregiver, 295 participants were asked to complete a Korean posttraumatic growth inventory, translated from the Posttraumatic Growth Inventory (PTGI; J Trauma Stress 1996; 9: 455.471), together with the Caregiver burden scale, life style interruption scale, economic burden scale and positive adaptation scale, social support scale and questions about religious and demographic factors. Cronbach's alpha was 0.95 for the K-PTGI, indicating sufficient internal consistencies. Construct and Criterion validity were also supported. K-PTGI appeared to be a sound measure for the experience of posttraumatic growth in cancer caregivers and this study result will be able to contribute to facilitate future research.

Optical Properties of InP/InGaP Quantum Structures Grown by a Migration Enhanced Epitaxy with Different Growth Cycles

  • Oh, Jae Won;Cho, Il-Wook;Ryu, Mee-Yi;Song, Jin Dong
    • Applied Science and Convergence Technology
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    • v.24 no.3
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    • pp.67-71
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    • 2015
  • InP/InGaP quantum structures (QSs) were grown on GaAs (001) substrates by a migration-enhanced molecular beam epitaxy method. Temperature-dependent photoluminescence (PL) and emission wavelength-dependent time-resolved PL (TRPL) were performed to investigate the optical properties of InP/InGaP QSs as a function of migration enhanced epitaxy (MEE) growth cycles from 2 to 8. One cycle for the growth of InP QS consists of 2-s In and 2-s P supply with an interruption time of 10 s after each source supply. As the MEE growth cycle increases from 2 to 8, the PL peak is redshifted and exhibited different (larger, comparable, or smaller) bandgap shrinkages with increasing temperature compared to that of bulk InP. The PL decay becomes faster with increasing MEE cycles while the PL decay time increases with increasing emission wavelength. These PL and TRPL results are attributed to the different QS density and size/shape caused by the MEE repetition cycles. Therefore, the size and density of InP QSs can be controlled by changing the MEE growth cycles.