• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.4-4
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• 2010

박막의 물성을 분석하는 방법에는 광학을 이용한 분광학 분석법과 나노크기의 tip을 이용한 나노트라이볼로지 분석법이 대표적이라 할 수 있다. 분광학 분석법에는 주로 X-ray 회절분석, Raman 분광기, IR 분광기 등등이 가장 대표적으로 사용되어지는 분석 장치들이다. 이러한 분광학 분석은 광학을 시료에 조사하여 이로부터 획득되는 강도(intensity)를 분석하는 방법으로 간접적인 분석이라 할 수 있다. 이에 반하여 나노트라이볼로지는 나노크기의 tip을 이용하여 시료 표면을 직접적인 방법으로 분석하여 시료의 형상, 탄성, 강도, 마찰력 등의 정보를 제공하며, tip에의 전기적 신호를 부과하여 시료 표면의 국부적인 potential, electric current를 측정하게 된다. 이에 해당되는 대표적인 분석 장치로는 nano-indenter system과 SPM (Scanning Probe Microscopy)이 있다. 따라서, 이 논문에서는 나노트라이볼로지의 대표적인 장치인 nano-indenter system과 SPM에 대한 간단한 원리를 소개하고 다양한 분야에 대한 실제적인 분석을 사례를 통하여 나노트라이볼로지의 가치를 확인하고자 한다.

• Journal of Food Hygiene and Safety
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• v.31 no.5
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• pp.311-318
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• 2016

Azorubine is a synthetic tar color containing azo-bond in the molecular structure. This food colorant has been allowed to be used for beverages, cheese and dried fruits in the European Union and for some food in Australia. Even though it is applicable as a food color in many countries, this compound has not been permitted in Korea so far as a food additive. Thus, this study was performed to establish an analysis method for azorubine in Korea by comparison of three HPLC analysis methods for azorubine and other azo-compounds which are officially used in the European Food Safety Authority (EFSA, EU), the Food Standard Agency (FSA, England) and the National Institute of Food and Drug Safety Evaluation (NIFDS, Korea). The analysis method of the FSA for azorubine showed the best linearity ($r^2=0.999$), limit of detection (LOD, $0.07{\mu}g/mL$), limit of quantification (LOQ, $0.20{\mu}g/mL$), precision (0~0.5%) and accuracy (98.6~100.7%) among tested HPLC methods using a C-18 column and diode array detector (DAD) with ammonium acetate solution and acetonitrile as an eluent solution. Finally selected method of FSA was further verified by inter-day and intra-day experiments with linearity, LOD, LOQ, precision and accuracy. Recovery test showed the recover ratios of 97~103%, 95~101%, and 93~102% in beverages, breads/snacks and other foods, respectively. Inter-laboratory test represented the absolute value of z-score of less than 2 which means satisfactory levels in this test. Selected method of FSA showed reliable analytical results in application test using food samples collected in commercial markets in Europe.

• Journal of Conservation Science
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• v.16 s.16
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• pp.15-20
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• 2004

Two pieces of choson-Tongue(朝鮮通寶) minted at 1423 A.D. were analyzed by atomic absorption spectroscopy and neutron activation analysis. The measurement of lead isotope ratios was also carried out in order to predict the provenance of raw materials used for minting. The Chosen-Tongue was minted as bronze having the chemical compositions of $Cu\;90\%,\;Pb\;3\~4\%,\;Sn\;2\~3\%$, which were different from the typical composition of Chinese and Japanese coins. The results of lead isotope ratios showed that the provenance of raw materials used for minting had a possibility to be originated from South China. And application of statistical linear discriminant analysis (SLDA) to the provenance of lead used for minting of Chosen-Tongue was confirmed.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.5
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• pp.571-578
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• 1997

The development of new approaches for wheat grain hardness assessment may impact the grain industry in marketing, milling and breeding. This experiment was to develop a new method for fast identification between softness and hardness, and for maintaining germinability of seed after measurement in wheat. Results from the comparisons of accuracy and significance between image analysis and conventional methods(NIRS and textrometer) were summarized. Data obatined from image analysis for grain hardness did not show any difference from those of the conventional methods. The protein content analyzed by micro-Kjeldahl method was significantly correlated with the grain hardness measured by image analysis, textrometer, and NIRS. The analysis for wheat grain hardness using image analysis may be used as an alternative method to the conventional methods. This method also takes the seeds after analysis can be utilized as breeding materials in early generations.

• Journal of Korean Society for Geospatial Information Science
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• v.18 no.1
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• pp.83-88
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• 2010

This paper has analyzed Seoul metropolitan area on the basis of cluster characteristics and it is to understand the traits of each clusters. In order to modelize the area, 10 different indicators were selected among components of a city such as population, activities, land and facilities. Also through principal component analysis, similar characteristics or congenialities of the variables were derived as a common factor. The result was organized by factor score from hierarchical clustering method and as a final result, metropolitan area was clustered into five areas.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2011.04a
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• pp.400-403
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• 2011

본 논문에서는 시차열중량분석법과 X-선 회절분석법을 이용한 원전콘크리트의 탄산화에 의한 열화도 평가를 진행하였으며 두 가지 정성적 분석방법을 이용한 반정량적 평가 방법을 개발하였다. 원자력발전소 건설에 사용된 동일한 콘크리트 배합을 사용한 시편을 촉진 탄산화 시험장치에 28, 56, 91, 180, 365일 기간에 걸쳐 노출시켜 탄산화를 진행하였으며 노출된 시편은 시차열중량분석법, X-선 회절분석법을 이용하여 탄산화에 따라 발생된 열화생성물의 양을 정성적으로 분석하였다. 그 결과, 탄산화로 인해 발생되는 Calcite의 양이 노출기간에 따라 점차적으로 증가되는 것이 확인되었으며, Calcite의 생성을 위해 이산화탄소와 반응하는 Portlandite의 양이 점차적으로 감소되는 것이 확인되었다. 본 논문에서는 위의 언급된 두 방법의 관계성을 통해 열화도 평가를 진행하였다.

• Journal of Korea Water Resources Association
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• v.55 no.spc1
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• pp.1167-1175
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• 2022

In this study, management index method has been developed to estimate the level of deterioration, applied to Cheongju city, and compared with the previous estimation methods of deterioration level of water distribution system. From the results, distribution systems of Yullyang, Naedeok1 and Yongam2 are found to be seriously deteriorated. And it was also found that probability of pipe breakage was estimated as 3.21%, 4.64% which is highest level at the steel pipe of 200 mm and 300 mm diameter. It was found that risk degree was estimated as 0.2609, 0.2644 by using management index method in Naedeok1 which is the most dangerous distribution system in the city. It was also found that results of risk analysis by management index method have been similar with the results of safety analysis by reliability method and indirect estimation method of deterioration level. Therefore, newly developed management index method can be applied and may be useful to the estimation of deterioration level for the future maintenance and management of water distribution system.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.05a
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• pp.39.1-39.1
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• 2011

본 연구에서는 전해증착법을 이용하여 결정성 ZnTe 나노와이어를 성장시켰고, 구조적 및 전기적 특성을 평가하였다. 또한 나노와이어 성장에 앞서, 결정성 ZnTe 박막을 전해증착법으로 형성하였고, 그 박막의 특성을 관찰하였다. 화학양론적(stoichiometric) 조성을 가지는 박막을 성장시키기 위하여, 순환전류전압법(cyclicvoltammetry)을 이용하여 Zn, Te, 이온들과 구연산 착화체(citrate-complexes)로 구성된 수용액 전해질에서 각 원소의 환원전위 분석이 이루어졌고, 과전압(overpotential)과 전해질 온도와 농도등과 같은 전해증착 조건에 따라 박막을 증착하였다. 각 조건에서 전해증착된 박막은 주사전자현미경(SEM)과 EDS를 이용하여 표면과 두께 그리고 성분분석을 하였고, XRD 분석법을 이용하여 박막의 결정성 변화를 관찰하였다. 박막증착 실험에서의 알맞은 증착조건을 나노와이어 전해증착실험에 적용하여, 다공성의 양극산화알루미늄(Anodic Aluminium Oxide, AAO) 템플레이트를 이용하여 bottom-up 방식으로 결정성 ZnTe 나노와이어를 성장시켰다. 수산화 나트륨(NaOH)용액을 이용하여 템플레이트를 선택적으로 에칭하여 제거한 후, ZnTe 나노와이어의 구조적 및 전기적 특성을 분석하였다.

• Analytical Science and Technology
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• v.9 no.4
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• pp.399-405
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• 1996

The flavor compounds of the oil from roasted sesame seeds were collected by simultaneous steam distillation/ extraction(SDE) and dynamic headspace sampling(DHS) and were analyzed using a gas chromatograph equipped with a flame ionization detector and connected into a mass spectrometer. Among the flavor compounds collected by the SDE method, 46 compounds were identified. They consisted of 6 alcohols, 6 aldehydes, 5 ketones or acids, 4 furans or phenols, 12 pyrazines, 4 pyridines or thiazoles, and others. Thirty six compounds were identified by DHS and many of them were the same as those identified by the SDE method. However, some compounds such as 1-hexanol, pentanal, and dimethylsulfide were identified only by the DHS method.

• Journal of the Korean Chemical Society
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• v.44 no.4
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• pp.322-327
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• 2000

A new absorption spectrometric method for the determination of the Cr$_2O_7^{2-}$ ionin acidic media has been developed. The new method is based on the oxidation-reduction reaction of the HCr$O_4^-$ ion with H$_2$O$_2$forming a deep blue CrO(O$_2$) $_2$ andis coupled with a technique of flow injection analysis(FIA). The new method provides a linear calibration curve which accurately follows the Beer's law over a wide range of the analytical concentrations(2.0 ${\times}$ $10^{-6}$M~8.0 ${\times}$ $10^{-3}$M) of K$_2$Cr$_2$O$_2$. The sensitivity of the new method is approximately two times greater than the current method and the effects of the interfering substances such as V, Co, Ni, Fe, and Mn are almost negligible except Cu.