• 천문학회지
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• 제31권1호
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• pp.1-17
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• 1998

To understand the basic physics underlying large spatial fluctuations of intensity and Doppler shift, we have investigated the dynamical charctersitics of the transition region of the quiet sun by analyzing a raster scan of high resolution UV spectral band containing H Lyman lines and a S VI line. The spectra were taken from a quiet area of $100'\times100'$ located near the disk center by SUMER on board SOHO. The spectral band ranges from 906 A to 950 A with spatial and spectral resolution of 1v and $0.044 {\AA}$, respectively. The parameters of individual spectral lines were determined from a single Gaussian fit to each spectral line. Then, spatial correlation analyses have been made among the line parameters. Important findings emerged from the present analysis are as follows. (1) The integrated intensity maps of the observed area of H I 931 line $(1\times10^4 K)$ and S VI 933 line $(2\times10^5 K)$ look very smilar to each other with the same characterstic size of 5". An important difference, however, is that the intensity ratio of brighter network regions to darker cell regions is much larger in S VI 933 line than that in H I 931 line. (2) Dynamical features represented by Doppler shifts and line widths are smaller than those features seen in intensity maps. The features are found to be changing rapidly with time within a time scale shorter than the integration time, 110 seconds, while the intensity structure remains nearly unchanged during the same time interval. (3) The line intensity of S VI is quite strongly correlated with that of H I lines, but the Doppler shift correlation between the two lines is not as strong as the intensity correlation. The correlation length of the intensity structure is found to be about 5.7' (4100 km), which is at least 3 times larger than that of the velocity structure. These findings support the notion that the basic unit of the transition region of the quiet sun is a loop-like structure with a size of a few $10^3 km$, within which a number of unresolved smaller velocity structures are present.

• 한국환경과학회지
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• 제17권8호
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• pp.933-941
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• 2008

The formation of $Co_nTiO_{n+2}$ compounds, i.e., $CoTiO_3$ and $CO_2TiO_4$, in a 5wt% $CoO_x/TiO_2$ catalyst after calcination at different temperatures has been characterized via scanning electron microscopy (SEM), Raman and X-ray photoelectron spectroscopy (XPS) measurements to verify our earlier model associated with $CO_3O_4$ nanoparticles present in the catalyst, and laboratory-synthesized $Co_nTiO_{n+2}$ chemicals have been employed to directly measure their activity profiles for CO oxidation at $100^{\circ}C$. SEM measurements with the synthetic $CoTiO_3$ and $CO_2TiO_4$ gave the respective tetragonal and rhombohedral morphology structures, in good agreement with the earlier XRD results. Weak Raman peaks at 239, 267 and 336 $cm^{-1}$ appeared on 5wt% $CoO_x/TiO_2$ after calcination at $570^{\circ}C$ but not on the catalyst calcined at $450^{\circ}C$, and these peaks were observed for the $Co_nTiO_{n+2}$ compounds, particularly $CoTiO_3$. All samples of the two cobalt titanate possessed O ls XPS spectra comprised of strong peaks at $530.0{\pm}0.1$ eV with a shoulder at a 532.2-eV binding energy. The O ls structure at binding energies near 530.0 eV was shown for a sample of 5 wt% $CoO_x/TiO_2$, irrespective to calcination temperature. The noticeable difference between the catalyst calcined at 450 and $570^{\circ}C$ is the 532.2 eV shoulder which was indicative of the formation of the $Co_nTiO_{n+2}$ compounds in the catalyst. No long-life activity maintenance of the synthetic $Co_nTiO_{n+2}$ compounds for CO oxidation at $100^{\circ}C$ was a good vehicle to strongly sup port the reason why the supported $CoO_x$ catalyst after calcination at $570^{\circ}C$ had been practically inactive for the oxidation reaction in our previous study; consequently, the earlier proposed model for the $CO_3O_4$ nanoparticles existing with the catalyst following calcination at different temperatures is very consistent with the characterization results and activity measurements with the cobalt titanates.

• Journal of Plant Biotechnology
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• 제33권4호
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• pp.283-288
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• 2006

건조된 벼 5 품종의 whole cell extracts로부터 $^1H$ NMR 스펙트럼 조사를 통해 다변량 통계분석법을 활용하여 벼 종자의 품종 구분이 가능함을 조사하였다. $^1H$ NMR스펙트럼 데이터에 기초한 PCA분석 결과 크게 3개의 그룹으로 구분이 이루어졌다. 즉, 상주벼가 나머지 4 품종의 벼와 크게 다르게 구분이 이루어졌으며 동진벼와 심백벼, 그리고 화만벼와 심백hetero 품종이 각각 하나의 소그룹으로 구분이 이루어졌다. 스펙트럼 영역에 있어서는 carbohydrate region이 품종에 따라 크게 달라지는 것으로 보아 탄수화물의 정량정성적 차이가 metabolic profiting에 의한 품종 구분에 중요한 역할을 하는 것으로 추론된다. 또한 $^1H$ NMR 스펙트럼 데이터에 기초하여 주요 당 화합물 (sucrose, glucose, maltose 등)의 상대적인 정량분석을 조사한 결과 상주벼의 경우 다른 벼 품종에 비해 sucrose 및 glucose 함량은 큰 차이가 없었으나 maltose 함량이 타 품종에 비해 약 2-4배 높음을 알 수 있었다. 따라서 본 연구에서 확립한 벼 종자의 whole cell extracts로부터 $^1H$ NMR 스펙트럼을 이용한 metabolic profiling 방법은 다양한 벼 종자의 신속한 품종구분은 물론 주요 carbohydrates의 간편한 정량분석 체계로 활용이 가능할 것으로 예상된다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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• pp.265-265
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• 2012

The adsorption of molecular $NH_3$ on rutile $TiO_2(110)-1{\times}1$ surfaces was investigated using a temperature-programmed desorption (TPD) technique combined with a molecular beam apparatus. A quantitative investigation into the TPD spectra of $NH_3$ was made for $NH_3$ adsorbed on two kinds of rutile $TiO_2(110)-1{\times}1$ surfaces with the oxygen vacancy ($V_O$) concentration of ~0% (p-$TiO_2(110)$) and ~5% (r-$TiO_2(110)$), respectively. On both surfaces, non-dissociative adsorption of $NH_3$ was inferred from a quantitative analysis on the amount of adsorbed $NH_3$ and those desorbed. With increasing coverage, the monolayer desorption feature shifted from 400 K toward lower temperatures until it saturates at 160 K, suggesting a repulsive nature in the interaction between $NH_3$ molecules. At the very low coverage regime, the desorption features were found to extend up to 430 K and 400 K on p-$TiO_2(110)$ and p-TiO(110), respectively. As a result, the saturation coverage of monolayer of $NH_3$ was higher on the p-$TiO_2(110)$ surface than on the p-TiO(110) by about 10%. The desorption energy ($E_d$) of $NH_3$ obtained by inversion of the Polanyi-Wigner equation indicated that the difference between the $E_d$'s of $NH_3$ (that is, $E_d(on\;p-TiO_2(110)$) - $E_d$(on p-TiO(110)) was 14 kJ/mol at ${\theta}(NH_3)=0$ and decreased to 0 as the coverage approached to a monolayer. The observed adsorption behavior of $NH_3$ was interpreted using an interaction model between $NH_3$ and surface defects on $TiO_2$ such as VO's and $Ti^{3+}$ interstitials.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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• pp.433-433
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• 2012

As the requirement in patterning geometry continuously shrinks down, the termination of etch process at the exact time became crucial for the success in nano patterning technology. By virtue of real-time optical emission spectroscopy (OES), etch end point detection (EPD) technique continuously develops; however, it also faced with difficulty in low open ratio etching, typically in self aligned contact (SAC) and one cylinder contact (OCS), because of very small amount of optical emission from by-product gas species in the bulk plasma glow discharge. In developing etching process, one may observe that coupon test is being performed. It consumes costs and time for preparing the patterned sample wafers every test in priority, so the coupon wafer test instead of the whole patterned wafer is beneficial for testing and developing etch process condition. We also can observe that etch open area is varied with the number of coupons on a dummy wafer. However, this can be a misleading in OES study. If the coupon wafer test are monitored using OES, we can conjecture the endpoint by experienced method, but considering by data, the materials for residual area by being etched open area are needed to consider. In this research, we compare and analysis the OES data for coupon wafer test results for monitoring about the conditions that the areas except the patterns on the coupon wafers for real-time process monitoring. In this research, we compared two cases, first one is etching the coupon wafers attached on the carrier wafer that is covered by the photoresist, and other case is etching the coupon wafers on the chuck. For comparing the emission intensity, we chose the four chemical species (SiF2, N2, CO, CN), and for comparing the etched profile, measured by scanning electron microscope (SEM). In addition, we adopted the Dynamic Time Warping (DTW) algorithm for analyzing the chose OES data patterns, and analysis the covariance and coefficient for statistical method. After the result, coupon wafers are over-etched for without carrier wafer groups, while with carrier wafer groups are under-etched. And the CN emission intensity has significant difference compare with OES raw data. Based on these results, it necessary to reasonable analysis of the OES data to adopt the pre-data processing and algorithms, and the result will influence the reliability for relation of coupon wafer test and whole wafer test.

• Journal of Applied Biological Chemistry
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• 제63권1호
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• pp.29-33
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• 2020

한약재의 불법 유통을 방지하기 위해 신속 정확한 원산지 판별방법 개발이 필요함에 따라 TDU-GC/MS를 이용하여 한국품종 당귀와 외국품종 당귀를 판별함과 동시에 한국품종 당귀의 재배지가 한국인지를 판별할 수 있는 기법을 연구하였다. 당귀추출물을 열탈착 시킨 후 냉각응축시스템에서 응축시켜 일시에 GC/MS로 분석한 결과 국산 품종 당귀(참당귀)는 TIC의 RT 26.9-27.2에서 coumarin 유도체인 decursin과 decursinol peak가 확인되었다. 중국 품종 당귀(중당귀)의 경우 RT 17.2 부근에서 ligustilide의 peak가 검출되었다. 국산 품종 참당귀 원산지에 따른 휘발성분의 차이를 알아보기 위하여 twister로 흡착하여 TDU-GC/MS로 m/z 40-400 amu 범위에서 mass spectrum을 측정하였다. 참당귀의 국내 및 중국 재배 시료 TIC는 전반적으로 같은 경향을 냈으나 TIC를 부분 scan한 결과 RT 15.4-16.1에서 국내 및 중국 재배의 peak pattern 차이를 확인할 수 있었다. Peak A (RT 15.54)과 B (RT 16.05)의 비율은 국내 재배는 0.0-0.2, 중국 재배의 경우 0.5-2.8으로서 TDU-GC/MS의 TIC peak pattern 비교를 통한 원산지 판별 가능성을 확인하였다.

• Journal of Biosystems Engineering
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• 제38권2호
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• pp.73-80
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• 2013

Purpose: This study was conducted to compare tillage and loads characteristics of three types of rotavators in farmland working condition of Korea. Methods: Tillage operations using three types of rotavators, i.e. rotary-type, crank-type and plow-type, were carried out in a dry field of Korea. The same prime mover tractor was used for driving three types of rotavators, and under several operational conditions, tillage characteristics such as actual working speed, rotavating depth, rotavating width, actual field capacity, flow of tilled soil, soil inversion ratio, and pulverizing ratio were measured. In addition, loads characteristics like torque and required power of Power Take-Off (PTO) shaft were calculated. Results: The average rotavating depth was smaller than the nominal value for all rotavators, and the difference was the greatest in the plow-type rotavator. Nevertheless, the plow-type rotavator showed the largest rotavating depth. The rotavating width was the same as the nominal value of all rotavators. The flow of tilled soil at the same operational conditions was the greatest in the plow-type rotavator and was the smallest in the rotary-type rotavator. In the most commonly used gear conditions of L2 and L3, the average soil pulverizing ratio was the greatest in the rotary-type rotavator, and followed by crank-type and plow-type rotavators in order. In the gear L2 and L3, the plow-type rotavator also had the lowest average soil inversion ratio while the rotary-type and crank-type rotavators had the same soil inversion ratio each other. The average torque and power of PTO shaft in the gear L2 and L3 were the highest in the plow-type rotavator. The load spectra of PTO shaft applying rain flow counting method and Smith-Waston-Topper equation to the measured torque showed that the modified torque amplitude was the greatest in the crank-type rotavator. This may come from the large torque fluctuation of crank-type rotavator during tillage operations. Conclusions: The three types of rotavators had different tillage and loads characteristics. The plow-type rotavator had the deepest rotavating depth, the smallest soil inversion ratio, the largest soil pulverizing ratio and required PTO power. Also, the crank-type rotavator showed a large torque fluctuation because of their unique operational mechanism. This study will help the farmers choose a suitable type of rotavator for effective tillage operations.

• Korean Chemical Engineering Research
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• 제48권6호
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• pp.757-762
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• 2010

제약산업에서 최종의약품의 품질과 성능은 결정분말의 크기, 모양 및 다형체 등에 의해서 크게 달라지므로, 원료의약품(API)의 결정화 공정은 매우 중요한 제약공정이다. 본 연구에서는 NIR 분광기와 광섬유 탐침을 이용하여, API 결정화 공정을 인라인 모니터링하여, 결정화 진행과정에서 핵성성, 결정성장, 다형체 등의 주요 특성을 실시간으로 감시하고 예측할 수 있는지를 탐구하였다. NIR 스펙트럼 분석에는 주요인분석법(PCA)을 적용하였고, 잘 알려진 aspirin를 대상 API로 하여 에탄올과 아세톤의 용매 혼합비율에 따른 결정특성 변화를 관찰하였다. 여러 특성분석 결과, 생성되는 aspirin 결정체의 다형은 용매 혼합비에는 무관하게 상온에서 가장 안정상인 form-I이었지만, 핵생성 개시점, 결정입도 및 결정의 형상은 용매의 혼합비에 따라 크게 달라진다는 것을 확인하였다. 이러한 결과는 NIR 스펙트럼의 PCA 해석결과와 매우 긴밀한 상관성을 보여주었다. 결론적으로, NIR 인라인 모니터링을 통해서, 약물의 결정화 과정에서 관심사가 되는 주요 결정특성을 실시간으로 관찰하고 예측할 수 있음이 실증되었다.

• 한국자기학회지
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• 제17권1호
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• pp.47-50
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• 2007

최근 geometrical frustration 현상 및 멀티페로익 효과가 Cr 이온의 나선 스핀 구조에 기인하는 것으로 해석되고 있다. 이에 본 연구에서는 Cr 이온 자리에 Fe을 치환하여 $CoCrFeO_4$를 제조하였고, $M\"{o}ssbauer$ 분광법에 의해 자기적 미세 구조의 상관관계를 연구하였다. 졸겔법을 이용하여 Fd3m의 cubic 스피넬 구조를 갖는 $CoCr_2O_4,\;CoCrFeO_4$ 단일상을 합성하였고, Rietveld 법에 의한 분석결과 격자상수는 $a_0=8.340$에서 $8.377{\AA}$로 증가 하였으며, Cr, Fe 이온은 모두 팔면체 구조에 위치하는 것으로 분석되었다. 자기 상전이 온도는 $T_N=97K$에서 320 K로 증가하였으며, 상호작용의 변화에 따라서 field cooled 온도에 따른 자화 곡선의 변화를 관측하였다. $M\"{o}ssbauer$ 스펙트럼 분석결과 4.2 K에서 공명흡수선에 대한 초미세자기장($H_{hf}$) 값은 각각 507, 492 kOe 정도로 나타났으며, 이성질체 이동치($\delta$)는 0.33, 0.34 mm/s 정도로 Fe 이온상태가 둘 다 +3 가의 이온상태임을 알 수 있었다.

• 한국식품저장유통학회지
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• 제12권1호
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• pp.48-53
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• 2005

방사선 조사(5, 10 kGy)와 훈증처리$(MeBr,\;PH_3)$된 건고추의 저장조건(실온,4, 8개월)에 따른 미생물학적, 수분함량, 기계적 색도 및 흡광특성에 미치는 영향을 검토하였다. 처리군별 미생물 농도에서 무처리 시료의 총세균은 분말 고추 $4.8\times10^5\;CFU/g$, 통고추 $1.8\times10^2\;CFU/g$ 수준이었고, 효모 및 곰팡이는 분말 고추 $1.7\times10^5\;CFU/g$, 통고추 $5.0\times10^2\;CHU/g$수준으로 통고추에 비해 분말 고추가 높은 미생물 농도를 나타내었다. 그러나 대장균군은 모든 시료에서 검출되지 않았다. 특히, 화학 훈증제는 살균 효과가 거의 나타나지 않았으나 5 kGy범위의 감마선 조사는 모든 미생물 농도를 $2\~3\;log$ cycle 이상 감소시킬 수 있었다. 건고추의 수분함량은 감마선과 훈증처리에 의해 거의 변화되지 않았으나 저장조건의 영향이 크게 나타났다. 건고추 과육 추출물의 흡광특성은 처리군간에 차이가 없었다. 과피의 명도(L)는 처리직후 10 kGy 조사군과 MeBr 처리군에서 적색도(a)와 황색도(b)는 감마선과 훈증처리군에서 각각 낮은 (p<0.05) 값을 보였으나 저장 4개월 이후에는 무처리군과 처리군간에 유의적이 차이가 없었으며, 저장기간은 시료의 색도변화에 유의적인 영향을 나타내었다.