• 천문학회보
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• 제42권1호
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• pp.32.1-32.1
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• 2017

To dynamically and chemically understand how filaments, dense cores, and stars form under different environments, we are conducting a systematic mapping survey of nearby molecular clouds using the TRAO 14 m telescope with high ($N_2H^+$ 1-0, $HCO^+$ 1-0, SO 32-21, and $NH_2D$ v=1-0) and low ($^{13}CO$ 1-0, $C^{18}O$ 1-0) density tracers. The goals of this survey are to obtain the velocity distribution of low dense filaments and their dense cores for the study of their origin of the formation, to understand whether the dense cores form from any radial accretion or inward motions toward dense cores from their surrounding filaments, and to study the chemical differentiation of the filaments and the dense cores. Until Feb. 2017, the real OTF observation time is 460 hours. We have almost completed mapping observation with four molecular lines ($^{13}CO$ 1-0, $C^{18}O$ 1-0, $N_2H^+$ 1-0, and $HCO^+$ 1-0) on the five regions of molecular clouds (L1251 of Cepheus, Perseus west, Polaris south, BISTRO region of Serpense, California, and Orion B). The maps of a total area of $7.38deg^2$ for both $^{13}CO$ and $C^{18}O$ lines and $2.19deg^2$ for both $N_2H^+$ and $HCO^+$ lines were obtained. All OTF data were regridded to a cell size of 22 by 22 arcseconds. The $^{13}CO$ and $C^{18}O$ data show the RMS noise level of about 0.22 K and $N_2H^+$ and $HCO^+$ data show about 0.14 K at the velocity resolution of 0.06 km/s. Additional observations will be made on some regions that have not reached the noise level for analysis. We are refining the process for a massive amount of data and the data reduction and analysis are underway. This presentation introduces the overall progress from observations to data processing and the initial analysis results to date.

• 한국결정성장학회지
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• 제10권3호
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• pp.219-225
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• 2000

스피넬형의 $LiMn_2$O$_4$는 출발물질로 LiOH와 Mn($CH_3$COO)$_2$.$4H_2$O를 사용하여 졸-겔법으로 합성한 xerogel을 $150^{\circ}C$로 1차 열처리한 후 $350^{\circ}C$로 2차 열처리하여 합성하였다. 그러나 $350^{\circ}C$ 이상으로 열처리할 경우 $Mn_2O_3$가 생겼으며, 이로 인해서 Li/lM $LiClO_4$(in PC)$LiMn_2O_4$cell을 구성하여 0.25 mA/$\textrm{cm}^2$의 전류밀도로 충.방전 실험을 한 결과 $350^{\circ}C$에서 열처리한 것은 15 cycle후에 88 mAh/g에서 56 mAh/g으로 35.7%의 용량감소가 나타났으나 $500^{\circ}C$에서 열처리한 것은 89 mAh/g에 51 mAh/g으로 42.5%의 용량감소가 나타났으며 이는 $Mn^{3+}$ 의 증가로 인한 Jahn-Teller distortion의 결과로 볼 수 있다.

• KSBB Journal
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• 제20권6호
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• pp.453-457
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• 2005

우리는 황결핍 환경에서 C. reinhardtii에 의한 수소생산성을 증진시키기 위해 황성분의 농도가 수소생산에 미치는 영향을 조사하였고, 그 결과를 이용하여 황 재첨가에 의한 연속적인 수소생산을 수행하였다. $MgSO_4$ 용액을 농도별(0, 15, 30, 60, 120 ${\mu}M$)로 희석하여 황결핍 초기에 첨가하였을 때, 최적 황농도는 $30{\mu}M$로서 236 mL $H_2/L$ culture를 생산하였다. 황결핍 시 황성분의 첨가는 PSII 활성화에 기여하여 hydrogenase가 수소합성에 이용할 수 있는 전자를 다량 발생시키기 때문이다. 그러나 초기에 첨가해 준 황농도가 너무 높으면, 황결핍 시간이 지연($MgSO_4\;60{\mu}M$의 경우) 되거나 황결핍이 일어나지 않기($MgSO_4\;120{\mu}M$의 경우) 때문에 hydrogenase가 유도되지 않는다. 따라서 수소생산량이 다른 농도에 비해 감소하거나 수소가 전혀 생산되지 않았다. 연속적인 수소생산을 위한 황성분 재첨가는 총 4회 수행되었고, 발생된 총 수소생산량은 625 m/L $H_2/L$ culture였다. 그러나 황성분을 재첨가해 줄 때마다 수소생산량은 점차 감소되었다. 이것은 황결핍 조건에서 단일항 산소에 의한 chlorophyll 파괴 및 세포 수의 감소, 또한 배양액 내의 pH의 증가 때문에 수소생산이 감소된 것으로 사료된다. 따라서 황결핍 조건에서 조류를 이용한 연속적인 수소생산 공정을 개발하기 위해서 황성분 첨가시기를 조절하여 세포의 사멸을 방지하고, 배양액내 pH 조절을 위한 다양한 buffer 첨가 실험 등 수소생산성을 지속적으로 유지할 수 있는 다양한 연구가 필요하다.

• Journal of Periodontal and Implant Science
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• 제26권1호
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• pp.216-229
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• 1996

Interferon(IFN) is a sort of glycoproteins that are produced by activated lymphocyte, monocyte and fibroblast. IFN has anti-viral effects, immuno-defensive mechanism and regulating properties to the several kinds of cells that includes affect on the bone formation and resorption. The effect of IFN on the osteoclast & other tissue cells has been studied in a number of researchers with the limited reports on the osteoblast. The purpose of this study was to evaluate the effects of IFN on the osteoblastic function. The MC3T3/El cell(Mouse osteoblast) was incubated in ${\alpha}-minimum$ essential medium containing 10% FBS. To detect the cytotoxic effect of $IFN-{\gamma}$ on osteoblast, the cells were cultured in 96-well plate to which $IFN-{\gamma}$ of various concentrations were added for 2 days. After staining with trypan blue, total cells and living cells were counted under microscope. To determine the activity of alkaline phosphataset(ALP), various concentrations of $IFN-{\gamma}$ were treated to culture medium, and biochemical assay was performed. $IFN-{\gamma}$ and $IFN-{\gamma}$ plus cycloheximide were added to culture medium separately and then ALP activity were determined. To detect the effect of the $IFN-{\gamma}$ on the bone formation of osteoblast, long-term culture was performed, and calcified nodule formation were observed using von Kossa's staining. After the addition of $IFN-{\gamma}$ with various concentrations to the medium, no cytotoxic effect of $IFN-{\gamma}$ was detected at any concentration. The significant increase in ALP activity of osteoblast were found the concentration of $IFN-{\gamma}$ 500-2500U/ml and the culture time of 24-48 hours respectively. The enhancement of ALP activity by $IFN-{\gamma}$ of osteoblast was decreased significantly by the treatment of cycloheximide. After long-term culture of osteoblast, the nodule formation was found to be increased in number and density by the addition of 500 U/ml $IFN-{\gamma}$. These results suggest that $IFN-{\gamma}$ was affected on the bone formation of osteoblast. Forthemore this kind of study or $IFN-{\gamma}$ to osteoblast will be held continuously.

• 한국식품영양과학회지
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• 제41권6호
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• pp.846-852
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• 2012

멥쌀, 찹쌀, 찐멥쌀의 수분함량(9, 12, 15, 18%)과 즉석팽화기의 팽화온도(200, 210, $220^{\circ}C$)를 달리하여 제조한 즉석팽화스낵의 체적밀도, 색도, 수분용해지수와 수분흡착지수, 미세구조 등의 물리적 특성을 조사하였다. 즉석팽화스낵 제조 시 수분함량과 팽화온도가 증가함에 따라 체적밀도는 감소하는 경향을 나타내었다. 색도에서 수분함량이 감소할수록, 팽화온도가 증가할수록 L값은 감소하는 경향을 나타내었고 a, b값은 증가하는 경향을 나타내었다. 수분용해지수와 수분흡착지수는 수분함량과 팽화온도가 증가할수록 증가하는 경향을 나타내었다. 멥쌀, 찹쌀, 찐멥쌀 간에는 체적밀도, 파괴력, 수분용해지수와 수분흡착지수에서 차이를 나타내었고 색도에서는 큰 차이를 나타내지 않았다. 미세구조는 수분함량이 9%에서 15%로 증가함에 따라 기공의 크기가 작고 균일하게 분포되었으며 찹쌀 즉석팽화스낵의 기공이 가장 작고 균일하게 나타났다.

• 유기물자원화
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• 제27권4호
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• pp.51-59
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• 2019

실험실 규모 회분식 미생물전기분해전지 반응기 (유효부피 20 mL)를 이용하여 수소가스 생산 및 식종기간 특성을 조사하였다. 총 6 cycle 동안 0.9 V를 인가하여 식종슬러지 혼합 비율 (혐기성소화 슬러지:50 mM PBS)에 따른 수소생산 및 식종기간을 분석한 결과 혼합비 1:1 반응기에서 9.8-20.9 mL 수소를 생산하였으며, 수소함량은 66.8-79.6%로 가장 높게 나타났다. 식종기간에 있어서는 혼합비 1:1 반응기 기준으로 약 12일 정도부터는 수소생산 및 전류밀도가 증가하는 것으로 나타났다. 또한 혼합비 1:2, 1:3, 1:4 반응기의 경우 cycle (2-6 cycle)에 따라 수소가스 생산량이 3.7-7.1 mL, 농도 5.8-65.8%로 변화하였으며, 혼합비 1:5, 1:6, 1:7 반응기의 수소가스 생산량은 0.5-0.7 mL, 농도 1.8-7.1%로 나타나 최대 혼합비 1:4까지 식종하는 것이 적합할 것으로 판단된다.

• Nutrition Research and Practice
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• 제12권1호
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• pp.61-68
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• 2018

BACKGROUND/OBJECTIVES: This study aimed to test the association between APOA5 3'-UTR variants (rs662799) and cardiometabolic traits in Koreans. SUBJECTS/METHODS: For this study, epidemiological data, Apolipoprotein A5 (APOA5) genotype information, and lymphoblastoid cell line (LCL) biospecimens from a subset of the Ansung-Ansan cohort within the Korean Genome and Epidemiology study (KoGES-ASAS; n = 7,704) as well as epidemiological data along with genomic DNA biospecimens of participants from a subset of the Korea National Health and Nutrition Examination Survey (KNHANES 2011-12; n = 2,235) were obtained. APOA5 mRNA expression was also measured. RESULTS: APOA5 rs662799 genotype distributions in both the KoGES-ASAS and KNHANES groups were 50.6% for TT, 41.3% for TC, and 8.1% for CC, which are similar to those in previous reports. In both groups, minor C allele carriers, particularly subjects with CC homozygosity, had lower high-density lipoprotein (HDL) cholesterol and higher triglyceride levels than TT homozygotes. Linear regression analysis showed that the minor C allele significantly contributed to reduction of circulating HDL cholesterol levels [${\beta}=-2.048$, P < 0.001; ${\beta}=-2.199$, P < 0.001] as well as elevation of circulating triglyceride levels [${\beta}=0.053$, P < 0.001; ${\beta}=0.066$, P < 0.001] in both the KoGES-ASAS and KNHANES groups. In addition, higher expression levels of APOA5 in LCLs of 64 healthy individuals were negatively associated with body mass index (r = -0.277, P = 0.027) and circulating triglyceride level (r = -0.340, P = 0.006) but not significantly correlated with circulating HDL cholesterol level. On the other hand, we observed no significant difference in the mRNA level of APOA5 according to APOA5 rs662799 polymorphisms. CONCLUSIONS: The C allele of APOA5 rs662799 was found to be significantly associated with cardiometabolic traits in a large Korean population from the KoGES-ASAS and KNHANES. The effect of this genotype may be associated with post-transcriptional regulation, which deserves further experimental confirmation.

• 한국재료학회지
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• 제20권12호
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• pp.669-675
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• 2010

One of the greatest challenges for our society is providing powerful electrochemical energy conversion and storage devices. Rechargeable lithium-ion batteries and fuel cells are among the most promising candidates in terms of energy and power density. As the starting material, $TiCl_4{\cdot}YCl_3$ solution and dispersing agent (HCP) were mixed and synthesized using ammonia as the precipitation agent, in order to prepare the nano size Y doped spherical $TiO_2$ precursor. Then, the $Li_4Ti_5O_{12}$ was synthesized using solid state reaction method through the stoichiometric mixture of Y doped spherical $TiO_2$ precursor and LiOH. The Ti mole increased the concentration of the spherical particle size due to the addition of HPC with a similar particle size distribution in a well in which $Li_4Ti_5O_{12}$ spherical particles could be obtained. The optimal synthesis conditions and the molar ratio of the Ti 0.05 mol reaction at $50^{\circ}C$ for 30 minutes and at $850^{\circ}C$ for 6 hours heat treatment time were optimized. $Li_4Ti_5O_{12}$ was prepared by the above conditions as a working electrode after generating the Coin cell; then, electrochemical properties were evaluated when the voltage range of 1.5V was flat, the initial capacity was 141 mAh/g, and cycle retention rate was 86%; also, redox reactions between 1.5 and 1.7V, which arose from the insertion and deintercalation of 0.005 mole of Y doping is not a case of doping because the C-rate characteristics were significantly better.

• 한국재료학회지
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• 제20권12호
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• pp.676-680
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• 2010

Most TCOs such as ITO, AZO(Al-doped ZnO), FTO(F-doped $SnO_2$) etc., which have been widely used in LCD, touch panel, solar cell, and organic LEDs etc. as transparent electrode material reveal n-type conductivity. But in order to realize transparent circuit, transparent p-n junction, and introduction of transparent p-type materials are prerequisite. Additional prerequisite condition is optical transparency in visible spectral region. Oxide based materials usually have a wide optical bandgap more than ~3.0 eV. In this study, single-phase transparent semiconductor of $SrCu_2O_2$, which shows p-type conductivity, have been synthesized by 2-step solid state reaction at $950^{\circ}C$ under $N_2$ atmosphere, and single-phase $SrCu_2O_2$ thin films of p-type TCOs have been deposited by RF magnetron sputtering on alkali-free glass substrate from single-phase target at $500^{\circ}C$, 1% $H_2$/(Ar + $H_2$) atmosphere. 3% $H_2$/(Ar + $H_2$) resulted in formation of second phases. Hall measurements confirmed the p-type nature of the fabricated $SrCu_2O_2$ thin films. The electrical conductivity, mobility of carrier and carrier density $5.27{\times}10^{-2}S/cm$, $2.2cm^2$/Vs, $1.53{\times}10^{17}/cm^3$ a room temperature, respectively. Transmittance and optical band-gap of the $SrCu_2O_2$ thin films revealed 62% at 550 nm and 3.28 eV. The electrical and optical properties of the obtained $SrCu_2O_2$ thin films deposited by RF magnetron sputtering were compared with those deposited by PLD and e-beam.

• 한국재료학회지
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• 제30권10호
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• pp.566-572
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• 2020

In the recent years, thin film solar cells (TFSCs) have emerged as a viable replacement for crystalline silicon solar cells and offer a variety of choices, particularly in terms of synthesis processes and substrates (rigid or flexible, metal or insulator). Among the thin-film absorber materials, SnS has great potential for the manufacturing of low-cost TFSCs due to its suitable optical and electrical properties, non-toxic nature, and earth abundancy. However, the efficiency of SnS-based solar cells is found to be in the range of 1 ~ 4 % and remains far below those of CdTe-, CIGS-, and CZTSSe-based TFSCs. Aside from the improvement in the physical properties of absorber layer, enormous efforts have been focused on the development of suitable buffer layer for SnS-based solar cells. Herein, we investigate the device performance of SnS-based TFSCs by introducing double buffer layers, in which CdS is applied as first buffer layer and ZnMgO films is employed as second buffer layer. The effect of the composition ratio (Mg/(Mg+Zn)) of RF sputtered ZnMgO films on the device performance is studied. The structural and optical properties of ZnMgO films with various Mg/(Mg+Zn) ratios are also analyzed systemically. The fabricated SnS-based TFSCs with device structure of SLG/Mo/SnS/CdS/ZnMgO/AZO/Al exhibit a highest cell efficiency of 1.84 % along with open-circuit voltage of 0.302 V, short-circuit current density of 13.55 mA cm^-2, and fill factor of 0.45 with an optimum Mg/(Mg + Zn) ratio of 0.02.