• 한국표면공학회지
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• 제9권2호
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• pp.1-7
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• 1976

The dissolving and growth kinetics of intermetallic compounds for the reaction between solid iron and molten zinc were studied under nitorgen atmosphere over the temperature range between470$^{\circ}C$ and 680$^{\circ}C$. The rates of dissolution of solid iron into molten zinc were obtained under a static conditon, The amount of dissolution of sold iron and the growth of intermetalic compounds could be determined by means of microscopy. The thickness of intermetallic compound at a given temperature increases with increasing time, whereas for a given time decreases with increasing temperature . The rate of dissolution is controlled by the diffusion process of iron in the effective boundary layer of molten zinc over the temperature range 470$^{\circ}$-530$^{\circ}C$, 570$^{\circ}$-620$^{\circ}C$, and 650$^{\circ}$-665$^{\circ}C$, while by the surface reaction over the range 530$^{\circ}$-570$^{\circ}C$ and 620$^{\circ}$-650$^{\circ}C$.

• 한국항만학회지
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• 제13권2호
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• pp.323-332
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• 1999

The bus should supply an equal service to the whole community as feeder trip. However the existing bus route can not supply an effective feeder service in spite of the changes in the latent demand by the variety of regional structural change. This study aimed to establish the concept which frames the bus operation and management to cope with the latent demand to the bus. This study tackled this evidence by analyzing the transportation problems in terms of the urban growth emphasizing the following issues ; First, the strategy to improve the bus operation Second the land use control appropriate for the public transportation network Third economical range to justify the bus operation Second, the land use control appropriate for the public transportation network Third, economical range to justify the bus operation Fourth, the allowance for the private transportation mode On the latter part, the difference on the bus operation was compared to determine the range within which the bus operation could be justified. This study would provide some implications to improve the management for bus operation and fundamental information to develop the bus operation system.

• 한국결정성장학회지
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• 제6권4호
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• pp.480-492
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• 1996

Al이 2 wt% 포함되어 있는 Zn 금속 target을 사용하여 반응성 직류 magnetron sputtering법으로 AZO(Aluminum doped Zinc Oxide) 투명전도막을 제막하였다. 반응성 가스인 산소의 분압과 유량을 조절하여 투과율과 전도도가 모두 우수한 전이영역을 발견하였고 전이영역을 안정적으로 유지하기 위한 증착조건을 찾아냈다. ZnO:Al막의 XRD분석결과 산화막이나 전이영역에서 증착된 막들은 ZnO결정의 (002)면의 peak가 유일하게 관찰되었다.

• 한국결정성장학회지
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• 제30권4호
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• pp.136-142
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• 2020

아연결정유약은 결정생성의 요건을 맞추기 위해서는 조핵제의 생성 - 조핵제의 양 조절 - 결정의 성장 등의 까다로운 소성과정을 거쳐야 한다. 소성온도 폭이 좁고 아연의 상태에 따라 결정에 영향을 미치는 등 사용이 용이하지 않다. 아연결정생성을 촉진시켜 이를 Frit화하여 폭넓은 소성조건에서 안정적으로 재결정화도록 하여 상용유약으로 유약을 개발할 수 있다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.208-213
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• 2004

Methods for estimation of the effective stress intensity factor range (${\Delta}K_{eff}$) are evaluated for narrow and wide band random loading crack growth test data of 2024-T351 aluminum alloy. Three methods of determining $K_{op}$, visual measurement, ASTM offset compliance method, and the neural network method proposed by Kang and Song, and three methods of estimating ${\Delta}K_{eff}$, conventional, the 2/PI0 and 2/PI methods proposed by Donald and Paris, are compared in a quantitative manner by using the results of fatigue crack growth life prediction under random loading. For all $K_{op}$ determination methods discussed, the 2/PI0 and 2/PI methods of estimating ${\Delta}K_{eff}$ provide better results than conventional method for narrow and wide band random loading data.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2010년도 제39회 하계학술대회 초록집
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• pp.149-149
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• 2010

The origin of the inhomogeneous distribution of photoluminescence (PL) peak wavelength on a commercial 2" GaN wafer for green light emitting diode has been investigated by wide momentum transfer (Q) range x-ray diffraction (XRD) profile of InGaN/GaN multiple quantum wells. Near the GaN (0004) Bragg peak, wide-Q range XRD (${\Delta}Q$ > $1.4{\AA}-1$) was measured along the growth direction. Wide-Q XRD gives precise and direct information of ultra-thin InGaN quantum well structure. Based on the QW structural information, the variation of PL spectra can be explained by the combined effect of temperature gradient and slightly uneven flow of atomic sources during the QW growth. In narrow variations of indium composition and thickness of QW, an effective indium composition can be a good character to match structural data to PL spectra.

• KSBB Journal
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• 제9권5호
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• pp.464-468
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• 1994

공업적 응용 가능성을 검토하기 위하여 한국의 근해 연얀저토에서 분리한 청색색소를 생성하는 Streptomyces sp.의 성질을 조사하였다. 탄 소원은 가용성 전분으로서 1% 였고, pH 7.0 이 상의 약 얄칼리성에셔 최대성장을 하였으며, 다량의 청색색소를 생생하였다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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• pp.203.1-203.1
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• 2013

Zinc oxide (ZnO) nanocrystalline thin films on various growth temperatures for active layer and different buffer layer thickness were grown by plasma-assisted molecular beam epitaxy (PA-MBE) on Si substrates. The ZnO active layer were grown with various growth temperature from 500 to $800^{\circ}C$ and the ZnO buffer layer were grown for different time from 5 to 40 minutes. To investigate the structural and optical properties of the ZnO thin films, scanning electron microscope (SEM), X-ray diffractometer (XRD), and photoluminescence (PL) spectroscopy were used, respectively. In the SEM images, the ZnO thin films have high densification of grains and good roughness and uniformity at $800^{\circ}C$ for active layer growth temperature and 20 minutes for buffer layer growth time, respectively. The PL spectra of ZnO buffer layers and active layers display sharp near band edge (NBE) emissions in UV range and broad deep level emissions (DLE) in visible range. The intensity of NBE peaks for the ZnO thin films significantly increase with increase in the active layer growth temperature. In addition, the NBE peak at 20 minutes for buffer layer growth time has the largest emission intensity and the intensity of DLE peaks decrease with increase in the growth time.

• Mycobiology
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• 제37권4호
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• pp.258-266
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• 2009

Pleurotus eryngii, known as king oyster mushroom has been widely used for nutritional and medicinal purposes. This study was initiated to screen the suitable conditions for mycelial growth and to determine the phylogenetic relationship of the selected strains. Optimal mycelial growth was observed at $30{^{\circ}C}$ and minimum mycelial growth observed at $10{^{\circ}C}$. This mushroom tolerates a broad pH range for mycelial growth, with most favorable growth observed at pH 6. Results also indicated that glucose peptone, yeast malt extract and mushroom complete media were favorable growth media, while Hennerberg and Hoppkins media were unfavorable. Dextrin was the best and xylose the least effective carbon sources. Results revealed that inorganic nitrogen sources were less effective than organic sources for the mycelial growth of P. eryngii. Investigation of genetic diversity is necessary to identify the strains. The ITS region of rDNA were amplified using PCR. The size of the ITS1 and ITS2 regions of rDNA from the different strains varied from 214 to 222 bp and 145 to 236 bp, respectively. The sequence of ITS2 was more variable than that of ITS1, and the 5.8S sequences were identical. A phylogenetic tree based on the ITS region sequences indicated that selected strains could be classified into six clusters. Fourteen IUM and ATCC- 90212 strains were also analyzed by RAPD with 20 arbitrary primers. Fourteen of these primers were efficiently amplified the genomic DNA. The number of amplified bands varied with the primers and strains, with polymorphic fragments in the range from 0.2 to 2.3 kb.

• 유통과학연구
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• 제10권6호
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• pp.7-15
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• 2012

The paper deals with the impact of information and communications technology on carbon emissions and economic growth in South Korea. The quarterly time series data from the first quarter of 1970 to the third quarter of 2010 (163 observations) are collected and retrieved from the Bank of Korea database. The paper examines long-run equilibrium relationships using cointegration techniques and Granger causality with vector error correction models. In directional causality tests, information and communications technology shows highly significant positive effects on economic growth and marginal effect on carbon emissions. Carbon emissions and economic growth exhibit an inverse relationship with each other; that is, carbon emissions have an inverse relation to economic growth and economic growth does not significantly affect carbon emissions in South Korea. We also note possible implications regarding growth policies and the information communications technology and "green" technology sectors for economies in the range represented by Korea's 1970 - 2010 data.