• 대한화학회지
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• 제25권6호
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• pp.343-350
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• 1981

P-Aminobenzaldehyde cyclohexylthiosemicarbazone의 결정 및 분자구조를 Computer controlled four circle diffractometer에 의한 X-선 회절방법으로 해명하였다. 결정은 공간군 C2/c의 단사형계에 속하며 단위세포 상수는 a = 12.488(2), b = 12.276(4), c = 19.997(6)${\AA}$, ${\beta}=103.55(3)^{\circ}$이고 z = 8이다. 구조는 중원자법과 Fourier 방법으로 규명하였으며 full-matrix 최소자승법으로 정밀화하였다. 최종 R값은 2712개의 회절반점에 대하여 0.058이었다. 분자는 N(2)-N(3)결합에대하여 C(8)-S는 trans, C(8)-N(1)은 cis형으로 놓여 있으며 N(1)과 N(3) 원자들이 분자내 수소결합을 만들고 있다. 의자모양의 cyclohexane 고리는 benzene 고리와 $40.7^{\circ}$의 면각을 이루고 있다. 결정내의 분자들은 수소 결합들로 모여져 있는데 $N(2)-H{\ldots}S$ 수소결합이 분자들을 이합체 꼴을 만들며 이들 분자들을 $N-H{\ldots}N$ 수소결합들이 이어주고 있다.

• 지구물리와물리탐사
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• 제10권4호
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• pp.229-240
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• 2007

이 연구에서는 지하 매질의 속도 이방성을 규명하고 이를 고려하여 지하 단면을 해석하는 탄성파 이방성 토모그래피(seismic anisotropic tomography) 알고리듬을 개발하였다. 이는 지하 매질을 대칭축이 기울어진 횡등방성(Tilted Transversely Isotropic) 매질로 가정하여 지하의 속도 구조와 더불어 이방성 구조를 함께 파악할 수 있도록 고안되었다. 개발된 알고리듬은 이방성 토모그래피에서 흔히 나타날 수 있는 역산의 안정성 문제를 해결하기위해여 역산 매개 변수를 역속도비, 역속도 그리고 이방성 대칭축 방향으로 설정하였고, 의사 베타 변환(pseudo-beta transform)을 통해 이방성 계수의 범위를 제한하였으며, ACB (Active Constraint Balancing) 법을 이용하여 효율적으로 역산 제한조건을 적용하였다. 특히, 기존의 등방성 토모그래피에서 사용하던 프레넬대(Fresnel volume)를 고려한 역산 기법을 이방성 토모그래피로 확장하여 파선 토모그래피에 비해 넓은 범위의 전파각 영역을 확보함으로써 이방성 토모그래피의 안정성을 높일 수 있었다. 개발된 이방성 토모그래피 알고리듬을 복잡한 수치 모델에 적용하여 알고리듬의 타당성을 검증하였으며 현장 자료에 적용하여 시추 결과 및 지질 정보들과 일치하는 향상된 결과를 얻었다. 개발된 이방성 토모그래피 알고리듬을 통해 지하매질의 속도 정보와 이방성 정보를 함께 고려함으로써 보다 정확한 지하 구조의 해석이 가능할 것으로 기대된다.

• 에너지공학
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• 제13권2호
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• pp.93-100
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• 2004

간접법을 이용한 표면오염도 측정 시 시료채취와 동시에 방사선 검출이 가능한 스메어 매체를 제조하고 성능을 평가하였다. 스메어 매체는 무기섬광체를 고분자 막에 함침시킨 것으로서, 용매로는 디메틸포름아마이드(DMF)와 메틸렌클로라이드(MC) 그리고 고분자 소재로서 폴리설폰(PSF)을 사용하였고, 무기섬광체는 CAYS(cerium activated yttrium silicate)를 사용하였다. 함침막은 단일 및 이중구조로 제조하였고, 물. 메타놀 등 비용매성 욕조에 침지하거나 용매 증발을 통하여 고형화하여 특성을 비교하였다. 방사선과의 상호작용에 의하여 무기섬광물질 함침막으로부터 방출되는 광자의 계측은 광전증배관과 고전압원, 증폭기. 계수기로 구성된 원형계수기를 사용하였다. $^{14}$ C표면오염에 대해 무기섬광 함침막을 이용해 얻은 계수율을 통상의 저준위 알파/베타 계수기로 얻은 결과와 비교할 때 상대 감도가 약 50%로 나타났다. 또한, 계수효율이 상대적으로 낮았지만 저에너지 베타선 방출핵종인 $^3$H표면오염도측정이 가능하다는 것을 확인하였다.

• Bulletin of the Korean Chemical Society
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• 제35권6호
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• pp.1697-1702
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• 2014

A novel complex [$Zn(phen)(o-AB)_2$] [phen: 1,10-phenanthroline o-AB: o-aminobenzoic acid] was synthesized and characterized by elemental analysis and X-ray diffraction single-crystal analysis. The crystal crystallizes in monoclinic, space group P2(1)/c with $a=7.6397(6){\AA}$, $b=16.8761(18){\AA}$, $c=17.7713(19){\AA}$, ${\alpha}=90^{\circ}$, ${\beta}=98.9570(10)^{\circ}$, ${\gamma}=90^{\circ}$, $V=2.2633(4)nm^3$, Z = 4, F(000) = 1064, S = 1.058, $Dc=1.520g{\cdot}cm^{-3}$, $R_1=0.0412$, $wR_2=0.0948$, ${\mu}=1.128mm^{-1}$. The Zn(II) is six coordinated by two nitrogen and four oxygen atoms from the 1,10-phenanthroline and o-aminobenzoic acid to furnish a distorted octahedron geometry. The complex exhibits intense fluorescence at room temperature. Theoretical studies of the title complex were carried out by density functional theory (DFT) B3LYP method. CCDC: 898291.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2010년도 하계학술대회 논문집
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• pp.388-388
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• 2010

In this study, Ferroelectric vinylidene fluoride-trifluoroethylene (VF2-TrFE) copolymer films were directly deposited on degenerated Si (n+, $0.002\;{\Omega}{\cdot}cm$) using by spin coating method. A 1~5 wt% diluted solution of purified vinylidene fluoride-trifluoroethylene (VF2:TrFE = 70:30) in a dimethylformamide (DMF) solvent were prepared and deposited on silicon wafers at a spin rate of 2000 ~ 4000 rpm for 2 ~ 30 seconds. After annealing in a vacuum ambient at 100 ~ $200^{\circ}C$ for 60 min, upper aluminum electrodes were deposited by vacuum evaporation for electrical measurement. X-ray diffraction results showed that the VF2-TrFE films on Si substrates had $\beta$-phase of copolymer structures. The capacitance on highly doped Si wafer showed hysteresis behavior like a butterfly shape and this result indicates clearly that the copolymer films have ferroelectric properties. The typical measured remnant polarization ($P_r$) and coercive filed ($E_c$) values were about $5.7\;{\mu}C/cm^2$ and 710 kV/em, respectively, in an applied electric field of ${\pm}$ 1.5 MV/em. The gate leakage current densities measured at room temperature was less than $7{\times}10^{-7}\; A/cm^2$ under a field of 1 MV/cm.

• 한국입자에어로졸학회지
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• 제10권1호
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• pp.1-8
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• 2014

In this study, we have developed a real-time monitoring device for measuring $PM_{10/2.5/1}$ of ambient aerosol particles. The real-time PM (Particulate Matter) monitor was based on the light scattering method and had 16 channels in particle size. The laboratory and field tests were carried out to evaluate the performance of the PM monitor developed. Arizona Road Dust particles ranging from diameter of 0.1 to $20{\mu}m$ were generated as test particles in the laboratory test. The field test was carried out at the Seoul Meteorological Observatory. We can obtain the particle size and number concentration (particle size distribution) only from the real-time PM monitor developed. Therefore, the average density of aerosol particles was used to obtain the PM data from the particle size distribution. The $PM_{10/2.5/1}$ results of the PM monitor were compared with the data of the Grimm Dust Monitor (Model 1.108) and a beta ray gauge (Thermo Fisher Scientific). As a result, it was shown that the $PM_{10/2.5/1}$ results obtained by the real-time PM monitor agreed well with the data of the reference devices, and overall, the real-time PM monitor could be used as a PM monitoring device for real-time monitoring of the ambient particles.

• Bulletin of the Korean Chemical Society
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• 제25권11호
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• pp.1661-1666
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• 2004

The reaction of titanium tetraisopropoxide with 2 equiv of N,N-diethyl acetoacetamide affords Ti($O^iPr)_2(CH_3COCHCONEt_2)_2$ (1) as colorless crystals in 80% yield. Compound 1 is characterized by spectroscopic (Mass and $^1H/^{13}C$ NMR) and microanalytical data. Molecular structure of 1 has been determined by a single crystal X-ray diffraction study, which reveals that it is a monomeric, cis-diisopropoxide and contains a six coordinate Ti(IV) atom with a cis($CONEt_2$), trans($COCH_3$) configuration (1a) in a distorted octahedral environment. Variable-temperature $^1H$ NMR spectra of 1 indicate that it exists as an equilibrium mixture of cis, trans (1a) and cis, cis (1b) isomers in a 0.57 : 0.43 ratio at -20$^{\circ}C$ in toluene-$d_8$ solution. Thermal properties of 1 as a MOCVD precursor for titanium dioxide films have been evaluated by thermal gravimetric analysis and vapor pressure measurement. Thin films of pure anatase titanium dioxide (after annealing above 500$^{\circ}C$ under oxygen) have been grown on Si(100) with precursor 1 in the substrate temperature range of 350- 500$^{\circ}$ using a bubbler-based MOCVD method.

• 한국표면공학회지
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• 제42권4호
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• pp.161-168
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• 2009

Effects of TiN/Ti multilayer coating on the Ti-30Ta-xZr alloy surface were studied by using various experiments. The Ti-30Ta containing Zr (5, 10 and 15 wt%) were melted 10 times to improve chemical homogeneity by using a vacuum furnace. And then samples were homogenized for 24 hrs at $1000^{\circ}C$. The specimens were prepared for TiN/Ti coating by cutting and polishing. The prepared specimens were coated with TiN/Ti multilayers by using DC magnetron sputtering method. The analyses of coated surface and coated layer were carried out by field emission scanning electron microscope(FE-SEM), EDX, and X-ray diffractometer(XRD). From the microstructure and XRD analysis of Ti-30Ta-xZr alloys, The equiaxed structure was changed to needle-like structure with increasing Zr content. And $\alpha$-peak and elastic modulus increased as Zr content increased. The $\alpha$ and $\beta$ phase predominantly were found in the specimen containing high Zr content. According to the analysis of TiN/Ti coating layer, the surface defects and structures of Ti-30Ta-xZr were covered with TiN/Ti coating layer and surface roughness decreased.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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• pp.169-170
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• 2006

In this study, ultra thin films of ferroelectric vinylidene fluoride-trifluoroethylene (VF2-TrFE) copolymer were fabricated on degenerated Si (n+, $0.002\;{\Omega}{\cdot}cm$) using by spin coating method. A 1~5 wt% diluted solution of purified vinylidene fluoride-trifluoroethylene (VF2:TrFE=70:30) in a dimethylformamide (DMF) solvent were prepared and deposited on silicon wafers at a spin rate of 2000~5000rpm for 30 seconds. After annealing in a vacuum ambient at $200^{\circ}C$ for 60 min, upper gold electrodes were deposited by vacuum evaporation for electrical measurement. X-ray diffraction results showed that the VF2-TrFE films on Si substrates had $\beta$-phase of copolymer structures. The capacitance on $n^+$-Si(100) wafer showed hysteresis behavior like a butterfly shape and this result indicates clearly that the dielectric films have ferroelectric properties. The typical measured remnant polarization (2Pr) and coercive filed (EC) values measured using a computer controlled a RT-66A standardized ferroelectric test system (Radiant Technologies) were about $0.54\;C/cm^2$ and 172 kV/cm, respectively, in an applied electric field of ${\pm}0.75\;MV/cm$.

• 한국식품과학회지
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• 제30권4호
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• pp.934-940
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• 1998

Kochujang, fermented hot pepper soybean paste, was prepared by traditional method, and irradiated with gamma ray of $^{60}Co{\;}up{\;}to{\;}15{\pm}1.5{\;}kGy$ for confirming main factor of kochujang fermentation. Nonirradiated (control) and irradiated samples kochujang were fermented at $25^{\circ}C$ and analyzed biochemical properties including enzyme activities and viable cell count during fermentation for 60 days. The total viable count in irradiated kochujang decreased to $10^4{\;}CFU/g$ which was $10^8{\;}CFU/g$ in the control. Because of a little changing enzyme activities of ${\alpha}{\cdot}{\beta}{\;}amylase$ and acid neutral protease by irradiation at the above level, amino type nitrogen which is the main quality reference of kochujang was comparable to the control. By irradiation, gas production was completely stopped which is one of biggest problems during distribution of kochujang. Total volume of gas produced at $25^{\circ}C$ from the control kochujang was 453 mL/100 g which was composed of over 90% of $CO_2$. The odor of irradiated kochujang was inferior to the control which seemed to be related to reduced microbial populations.