• 한국환경과학회지
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• 제26권2호
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• pp.173-181
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• 2017

Catch data for the common squid (Todarodes pacificus), classified by squid-jigging fisheries per grid (size: $0.5^{\circ}latitude{\times}0.5^{\circ}longitude$), and the water temperature values KODC (Korea Ocean Data Center) were collected for the 1980-2009 period to study the changes in squid distribution and migration with climate regimes (1980s, 1990s, and 2000s). The primary fishing period in the 1990s and 2000s was approximately 2-3 months earlier than that in the 1980s. Especially in the East Sea, the fishing grounds in the 1980s stayed longer at high latitudes than those in the other decades. Moreover, in the 1980s, centers of the fishing ground were located near the Yamato bank (central East Sea), whereas in the 1990s and 2000s, they were situated near the southeastern coast of the Korean peninsula.

• BMB Reports
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• 제42권6호
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• pp.387-392
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• 2009

Here, we report the first biochemical and structural characterization of the hypothetical protein HP0902 from Helicobacter pylori, in terms of structural genomics. Gel-permeation chromatography and dynamic light scattering indicated that the protein behaves as a dimer in solution. Circular dichroism spectroscopy showed that HP0902 primarily adopts a $\beta$-structure and the protein was highly thermostable with a denaturing temperature higher than $70^{\circ}C$. Finally, the backbone NMR assignments were obtained on the [$^{13}C,^{15}N$]HP0902 and the secondary structure was determined using the chemical shift data. Additionally, the local flexibility was assessed via a heteronuclear $^1H-^{15}N$ steady state NOE experiment. The results revealed that HP0902 would adopt a compactly folded, all-$\beta$ topology with 11 $\beta$-strands. All of the results clearly support the notion that HP0902 belongs to the cupin superfamily of proteins.

• 한국기계가공학회지
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• 제15권6호
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• pp.77-82
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• 2016

When drilling through Inconel 601 nickel-chromium-based alloys, a large amount of cutting oil is required to prevent tools from wear and fracturing due to heat buildup resulting from the high temperature resistance and toughness of this alloy. However, cutting oil supply has become a factor compromising the machining environment, and this has caused attention to shift to a more environmentally friendly cutting fluid supply system called minimum quantity lubrication (MQL). Our aim in this study was to find a more efficient drill processing method using MQL, and to verify its performance. To that end, we proposed a sealed cover, a step feed, and POSS-type cutting oil as measures to increase the effectiveness of MQL in view of the cutting force and tool wear, and established an improvement in efficiency using the proposed measures.

• JSTS:Journal of Semiconductor Technology and Science
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• 제1권3호
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• pp.158-166
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• 2001

Based on uniform hot carrier injection (optically assisted electron injection) across the $Si-SiO_2$ interface into the gate insulator of n-channel IGFETs, the threshold voltage shifts associated with electron injection of $1.25{\times}l0^{16}{\;}e/\textrm{cm}^2 between 0.5 and 7 MV/cm were found to decrease from positive to negative values, indicating both a decrease in trap cross section ($E_{ox}{\geq}1.5 MV/cm$) and the generation of FPC $E_{ox}{\geq}5{\;}MV/cm$). It was also found that FNC and large cross section NETs were generated for $E_{ox}{\geq}5{\;}MV/cm$. Continuous, uniform low-field (1MV/cm) electron injection up to $l0^{19}{\;}e/\textrm{cm}^2 is accompanied by a monatomic increase in threshold voltage. It was found that the data could be modeled more effectively by assuming that most of the threshold voltage shift could be ascribed to generated bulk defects which are generated and filled, or more likely, generated in a charged state. The injection method and conditions used in terms of injection fluence, injection density, and temperature, can have a dramatic impact on what is measured, and may have important implications on accelerated lifetime measurements.

• 공업화학
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• 제5권3호
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• pp.379-384
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• 1994

ethylene-vinyl alcohol(EVOH) 공중합체와 styrene-maleic anhydride(SMA) 공중합체를 포함하는 일련의 블렌드계에서 상용화 정도가 결정성 고분자 분산상의 결정화 거동에 미치는 영향을 조사하였다. 블렌드의 결정화거동과 morphology는 각각 시차열량분석기(DSC) 및 주사전자현미경(SEM)을 사용하여 확인하였다. 상용화 정도에 따라 분산상의 결정화 중 일부분이 저온 영역으로 크게 이동하여 나타났다 상용화 블렌드계에서 나타나는 이러한 결정화온도의 이동은 분산상의 homogeneous crystallization에 기인한 것이었다.

• KSBB Journal
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• 제8권2호
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• pp.185-191
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• 1993

산소발생능에 있어 오랜 기간 안정성을 유지하는 세포와 분리 틸라코이드 막을 단세포성 남조류인 Synechococcus PCC7002로부터 PVA로 고정화하여 구할 수 있었다. 분리 틸라코이드 막 및 고정화한 세포나 틸라코이드 막의 흡수스펙트럼의 굽대가 청색쪽으로 3nm정도 전이하였다. PVA에 고정화한 세포나 틸라코이드 막은 $4^{\circ}C$에 보관할 경우 광합성에 의한 전자전달 활성, 특히 광계 2의 활성을 오랜기간 보존할 수 있었다. 세포를 고온에 처리하였을 때 Fo와 Fv가 증가하였으나 고정화한 후에는 Fo의 변화가 거의 없었다. 이 결과는 고정화가 열처리에 의한 광계 2 복합체의 손상 특히 물분해기구의 손상에 대해 보호작용을 할 수 있음을 시사한다.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2004년도 추계학술대회 논문집
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• pp.263-268
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• 2004

In the present study, a Nd;YAG Laser (pulse type) was used to emit ultrasonic signals to a test material. In addition, a total ultrasonic investigation system was designed by adopting a Fabry-Perot interferometer, which receives ultrasonic signals without any contact. For non-destructive test SM45C, which contains some flaws was used as a test material. Because it is easy to align light beam in receiver, and the length of the light beam does not change much even if convex mirror leans towards one side, confocal Fabry-Perot interferometer, which has stable frequency, and PI control are used to correct interfered and unstable signals from temperature, fluctuation and time shift of laser frequency. Stable signals are always obtained by the feedback of PI circuit signals in the confocal Fabry-Perot interferometer. The type, size and position of flaws inside the test material were examined by achieving the stabilization of an interferometer. This study presented a useful method, which could quantitatively investigate the fault of objects by using a Fabry-Perot interferometer.

• 한국기계가공학회지
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• 제17권4호
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• pp.1-8
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• 2018

In drilling Inconel 601, which is used for compressor cases in aircraft engines, a lot of cutting oil must be supplied. This prevents tools from wear and fracture due to the heat buildup resulting from the high-temperature resistance and toughness of this alloy. However, the cutting oil supply has compromised the machining environment. This has caused attention to shift to an environmentally friendly cutting fluid supply system called the Minimum Quantity Lubrication(MQL) system. The aim of this study was to find a more efficient drill processing method using MQL and to verify its performance. To that end, the properties of Inconel that make it difficult -to -drill were studied by a comparison with the drilling of SM45C. Specific factors (i.e., cutting force and tool wear) were examined in relation to the conditions in the MQL-based drilling system. Based on these results, a sealed cover and step feed were proposed as measures to increase the effectiveness of the MQL system. The efficiency of the proposed method was established.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.378.2-378.2
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• 2014

We have investigated optical characteristics of $p-Ge_{0.99}Sn_{0.01}$ and Ge films grown on Si substrates using photoreflectance (PR) spectroscopy. The $Ge_{0.99}Sn_{0.01}$ and Ge films were grown by using an ultra-high vacuum chemical vapor deposition and molecular beam epitaxy methods, respectively. PR spectra were measured at 25 K and an extended InGaAs detector was used. By comparing $Ge_{0.99}Sn_{0.01}/Si$ and Ge/Si spectra, we observed the signals related to direct transition and split-off band of $Ge_{0.99}Sn_{0.01}$. The transition energies of $Ge_{0.99}Sn_{0.01}$ and Ge films were approximately 0.74 and 0.84 eV, respectively. Considering the shift of split-off band transition of $Ge_{0.99}Sn_{0.01}$, we suppose that the transition at 0.74 eV is attributed to direct transition between ${\Gamma}$ band and valence band. The temperature- and excitation power-dependent PR spectra were also measured.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.294-294
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• 2014

Developing magnetic thin films with desirable physical properties is a key step to promote research in spintronics. Organic-based magnetic material is a relatively new kind of materials which has magnetic properties in a molecular and microscopic level. These materials have been constructed by the coordination between 3d transition metal and organic materials producing long-range magnetic orders with a relatively high transition temperature. However, these materials were mostly synthesized as a form of powder, which is difficult to study for their physical properties as well as apply for electronic/spintronic devices. In this study, we have employed physical vapor deposition (PVD) to develop a new organic-based hybrid magnetic film that is achieved by the coordination of Fe and tetracyanoquinodimethane (TCNQ). The IR spectra of the grown film show modified CN vibration modes in TCNQ, which suggest a strong bonding between Fe and TCNQ. The thin film has both ferromagnetic and semiconducting behaviors, which is suitable for molecular spintronic applications. The high resolution photoemission (HRPES) spectra also show shift of 1s peak point of nitrogen and the carbon 1s peaks display traces of charge transfer from Fe to TCNQ as well as shake-up features, which suggest strong bonding and anti-bonding nature of coordination between Fe and TCNQ.