• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2001.10a
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• pp.660-664
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• 2001

$Zn_xSr_{1-x}S$ thin films were prepared in the whole composition range by rf sputtering, using powder targets of a mixture of ZnS and SrS with the required mole fraction. The possibility of existence of $Zn_xSr_{1-x}S$ solid solutions was systematically investigated from the results of thin film growth, in terns of structural, optical characteristics and the chemical bonding of the constituent atoms. The XRD, XPS and optical results made it clear that the solid solutions with a single-phased zincblende structure and a single-phased rocksalt structure were formed at $0.86~0.93{\leq}x{\leq}1$ and $0{\leq}x{\leq}0.29$, respectively. The miscibility gap, including phase separation regions was found to exist in $0.3{\leq}x{\leq}0.86~0.91$, in which lattice constants, binding energy and absorption edges kept almost constant by the same values as those at border compositions. The experimental results on phase transition agreed well with the fraction of ionic character $f_{i}$ based on the Phillips'dielectric theory.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.10a
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• pp.219-222
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• 2007

The paper deals with the rigorous analysis of three layered media structures. The dyadic Green's function for three layer medium is derived. The Green's functions belonging to the kernel of the integral equation are expressed as Sommerfeld integrals, in which surface wave effects are automatically included. We propose this integral representation as the most appropriate in the spatial domain analysis of slive structure. Also, we used extraction method for the convergence of this integral function. Finally, some numerical results are presented. These computed value show good agreement with proposed this method.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2009.05a
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• pp.309-312
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• 2009

본 논문에서는 탈색, 탈취 및 상 하수 정수처리에 많이 이용되고 있는 오존의 효과적인 발생을 위하여 세라믹을 이용하여 유전체 장벽 방전에 의한 오존생성특성을 연구하였다. 세라믹과 전극으로 구성된 전극 수와 오존생성을 위한 반응가스인 Air와 Oxygen의 투입량 변화에 따른 오존생성농도, 오존발생량 및 오존생성수율 특성을 분석하였다. 그 결과, 세라믹과 전극으로 구성된 전극 수가 많을수록 오존생성특성은 증가하였고, 원료가스를 Air와 Oxygen으로 사용한 경우 Oxygen을 원료가스로 사용했을 때 전극 수 5 및 10개에서 모두 오존생성특성이 우수하게 나타났으며, 그 결과 전극 수가 5개인 경우, 오존생성농도는 약 4.2배, 오존발생량은 2.5배, 오존생성수율은 2.5배 증가하였으며, 전극 수가 10개인 경우, 오존생성농도는 약 5.1배, 오존발생량은 3.8배, 오존생성수율은 3.4배 증가하였다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.323-324
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• 2006

저온동시 소결용 세라믹스, LTCC를 사용한 RF/MW용 고유전율 세라믹을 개발하기 위하여 300이상의 고유전율과 낮은 손실 계수를 가지는 것으로 알려진 $Ag(Nb_{1/4}Ta_{3/4})O_3$ 고용체와 $CaTiO_3$, $TiO_2$를 각각 혼합하여 공진주파수의 온도 계수가 0에 가까운 안정된 유전체 특성을 얻고자 하였다. 유전율의 온도 안정성을 도모하기 위해 음의 온도 계수를 갖는 $CaTiO_3$, $TiO_2$와 양의 온도계수를 갖는 $CaTiO_3$ 및 $TiO_2$를 일정 분율로 혼합한 복합체 구조의 시편을 제작하였다. LTCC 소자로의 적용을 위해 3wt.%의 CuO를 첨가하여 소결 온도를 낮추었으며, 소결 시편의 상 분석, 미세구조 및 전기적 특성을 조사하였다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11a
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• pp.594-597
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• 2004

본 연구에서는 진공 인라인 실장 기술을 이용하여 제작한 플라즈마 디스플레이 패널(PDP)의 전기적 광학적 특성을 측정하여, 일반적인 실장 방법을 이용한 PDP의 특성과 비교 분석하였다. 본 실험에 사용된 패널은 Screen Printer를 이용한 상 하부전극과 하판 유전체, 상판 투명유전체, 격벽 및 E-Beam Evaporation 방법을 이용하여 증착한 MgO 보호막으로 이루어져 있으며, 분위기 온도 $430^{\circ}C$, Ne-Xe(4%) 400[torr]압력 하에서 실장하였다. 높은 분위기 온도로 인하여 MgO에 Crack이 발생하였으나 지속적인 연구를 진행하여 최적의 실장 조건을 확립할 수 있었다. 이러한 진공 인라인 실장 기술은 추가적인 Annealing 공정이 필요하지 않아 공정의 단축을 모색할 수 있으며, MgO의 수화를 제거함으로써 일반적인 실장 방법을 이용한 패널보다 더 우수한 전기적 광학적 특성을 얻을 수 있었다.

• Korean Journal of Microbiology
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• v.55 no.2
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• pp.177-179
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• 2019

Pseudomonas kribbensis CHA-19 was isolated from a temperate forest soil (mid latitude) in New Jersey, USA, for its ability to degrade humic acids, a main component of humic substances (HS), and subsequently confirmed to be able to decolorize lignin (a surrogate for HS) and catabolize lignin-derived ferulic and vanillic acids. The draft genome sequence of CHA-19 was analyzed to discover the putative genes for depolymerization of polymeric HS (e.g., dye-decolorizing peroxidases and laccase-like multicopper oxidases) and catabolic degradation of HS-derived small aromatics (e.g., vanillate O-demethylase and biphenyl 2,3-dioxygenase). The genes for degradative activity were used to propose a HS degradation pathway of soil bacteria.

• Journal of Life Science
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• v.29 no.9
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• pp.1047-1054
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• 2019

Transposable elements (TEs) occupy approximately 45% of the human genome and can enter functional genes randomly. During evolutionary radiation, multiple copies of TEs are produced by duplication events. Those elements contribute to biodiversity and phylogenomics. Most of them are controlled by epigenetic regulation, such as methylation or acetylation. Every species contains their own specific mobile elements, and they are divided into DNA transposons and retrotransposons. Retrotransposons can be divided by the presence of a long terminal repeat (LTR). They show various biological functions, such as promoter, enhancer, exonization, rearrangement, and alternative splicing. Also, they are strongly implicated to genomic instability, causing various diseases. Therefore, they could be used as biomarkers for the diagnosis and prognosis of diseases such as cancers. Recently, it was found that TEs could produce miRNAs, which play roles in gene inhibition through mRNA cleavage or translational repression, binding seed regions of target genes. Studies of TE-derived miRNAs offer a potential for the expression of functional genes. Comparative analyses of different types of miRNAs in various species and tissues could be of interest in the fields of evolution and phylogeny. Those events allow us to understand the importance of TEs in relation to biological roles and various diseases.

• Journal of the Korean Vacuum Society
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• v.22 no.2
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• pp.55-65
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• 2013

Sterilization of Neurospora crassa has been investigated in this research by using a surface air plasma with dielectric barrier discharged (DBD) structure under atmospheric pressure. The sinusoidal alternating current has been used in this experiment with discharge voltage of 1.4~2.3 kV. The phase difference between the voltage and current signals are found to be almost 80 degree due to the capacitive property of dielectric barrier. Temperature on the biomaterials has been minimized by radiating the heat with the air cooling system. It is noted that the substrate temperature remains under 37 degree for plasma exposure time of 10 minutes with operation of cooler system. It is found that the ozone, $O_3$, has been measured to be about 25~30 ppm within 1 cm region and to be about 5 ppm at the 150 cm downstream region away from the suface plasma. It is also noted that the nitric oxide, NO, and nitric dioxide, $NO_2$, are not nearly detected. Germination rate and mitochodrial activity of Neurospora crassa immersed in the deionized water have been found to be drastically decreased as the plasma treatment time and its electrical power are increased in this experiment. Here, the mitochondrial activity has been analyzed by MTT (3-(4,5-dimethy lthiazol-2yl)-2,5-diphenyl-2H-tetrazolium bromide) assay. However, sterilization of Neurospora crassa immersed in the Vogel's minimal media has been found to be low by plasma treatment, which is caused by surrounding background solution. This research shows the sterilization possibility of Neurospora crassa by using the noncontated surface DBD plasma, which is different from the plasma jet. This is mainly attibuted to the reactive species generated by the surface plasma, since they play a major role for inhibition of micobes such as Neurospora crassa.

• 축산식품과학과 산업
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• v.12 no.2
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• pp.73-86
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• 2023

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.05a
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• pp.738-739
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• 2008

The SiOC film of carbon centered system was prepared using bistrimethylsilymethane and oxygen mixed precursor by the chemical vapor deposition. The chemical properties of he SiOC film were analyzed by the contact angle and FTIR spectra. The dielectric constant of the deposited films decreased after annealing process, and the correlation between the increasing the BTMSM/O2 flow rate ratio and he dielectric constant did not exist. However, the trend of increasing or decreasing of the dielectric constant repeated and here is the correlation ship between the dielectric constant and the Si-O-C bond in the range of $950{\sim}1200\;cm^{-1}$. The dielectric constant decreased between samples with the chemical shift. The lowest dielectric constant was 1.65 at the sample, which was observed he chemical shift.