• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.17 no.6
• /
• pp.264-271
• /
• 2007

The inorganic pigments of $Fe_2O_3-CoO-Cr_2O_3-MnO_2$ were synthesized by the co-precipitation method. $FeCl_3,\;CoCl_2,\;CrCl_3\;and\;MnCl_2$ are used for the starting raw materials, and 2 N-KOH for precipitator. $MnCl_2$ is secured with 10 mole%, and 6 composition ratios are used with three ingredients to synthesize the pigments. The samples were calcined at $1350^{\circ}C/1.5h$. The resulting pigments were characterized by using XRD, FT-IR, SEM, and UV spectrophotometer. 6wt% pigments were applied to lime glaze and lime-barium glaze respectively firing at $1260^{\circ}C$ for oxidation atmosphere and $1240^{\circ}C$ for reduction one. The results of color analysis by using UV spectrophotometer showed black, bluish black and dark grayish green.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.24 no.2
• /
• pp.103-110
• /
• 2020

Seismic qualification of instruments and devices mounted on electrical cabinets in a nuclear power plant is performed in this study by means of the in-cabinet response spectrum (ICRS). A simple method and two rigorous methods are proposed in the EPRI NP-7146-SL guidelines for generating the ICRS. The simple method of EPRI can give unrealistic spectra that are excessively conservative in many cases. In the past, the time domain analysis (TDA) methods have been mostly used to analyze a structure. However, the TDA requires the generation of an artificial earthquake input motion compatible to the target response spectrum. The process of generating an artificial earthquake may involve a great deal of uncertainty. In addition, many time history analyses should be performed to increase the accuracy of the results. This study developed a numerical analysis program for generating the ICRS by frequency domain analysis (FDA) method. The developed program was validated by the numerical study. The ICRS calculated by FDA thoroughly matched with those obtained from TDA. This study then confirms that the method it proposes can simply and efficiently generate the ICRS compared to the time domain method.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.29 no.1
• /
• pp.123-134
• /
• 2003

고속액체크로마토그래피 방법을 사용하여 동시에 arbutin, 메탄올에 녹인 methyl, ethyl, prpyl, butyl parben과 glablidien(유용성감초추출물)을 파장 254와 276 nm에서 Gradient methanol로 octdecyl culumn을 사용하여측정하였다. arbutin와 glablidien 농도 0.5-1.0 ug/ml 파라벤류는 0.1-2.0 ug/ml에서 검량선이 직선으로 작성되었다. 검량이 직선으로 나타나 정량분석을 할 수 있다는 것을 알 수 있었다. 샘플 전처리가 크로마토그래피로 측정하기에 좋은 방법이란 것을 판정하기 위하여 일반로션을 사용하여 판정하였다. 이 방법의 정확도는 모든 측정물질(arbutin, methylparaben, ethylparaben, propylparaben, butylparaben, glablidine)의 회수율 상대표준편차(RSD)가 (0.28-2.55%) 나타나 신뢰성 있는 결과를 보였다.A high-performance liquid chromatographic method for the simultaneous determination of arbutine, a mixture of methyl, ethyl, propyl, butyl parabens dissolved in methoanol and Glrablidine(Oil Soluble Licorice), was studied by using a ODS C18 column and a methanol gradient at 254 and 276 nm. Calibration curves were found to be linear in the 0.5-1.0 ug/ml range(compounds arbutine, glrablidin) and 0.1-20 ug/ml (compounds methylpaaben, ethylparaben, propylparaben, butylparaben). Linear regression analysis of the data demonstrates the efficacy of the method in terms of precision and accuracy. An extraction method is developed and validated in order to apply this chromatographic method to a cosmetic lotion. The presision of this method, calculated as the relativ standard deviation(RSD) of the recoveries(0.28-2.55%) was excellent for all compounds.

• Journal of the Society of Naval Architects of Korea
• /
• v.46 no.2
• /
• pp.136-147
• /
• 2009

The computational prediction method of speed performance for a ship with vortex generators is proposed. The Reynolds averaged Navier-Stokes equation has been solved together with the application of Reynolds stress turbulence model. The computations are carried out under identical conditions of the experimental method, i.e., towing and self-propulsion calculations without and with vortex generators. The speed performance in full scale is obtained through analyzing the computational results in model scale according to the revised model-ship performance analysis method of ITTC'78 with considering the vortex generators into account. The characteristics of resistance, self-propulsion and wake characteristics on the propeller plane are investigated. The proposed computational prediction clearly shows the effect of vortex generators and can be applicable to the design tool for vortex generators.

• Environmental and Resource Economics Review
• /
• v.23 no.4
• /
• pp.667-688
• /
• 2014

This research tested the EKC (Environment Kuznets Curve) Hypothesis using the $CO_2$ Emissions by region and GRDP. We built the panel data set on the 15 local government region from 1990 to 2010 for this analysis. GRDP, population and total factor productivity was considered as the factors influencing on the regional $CO_2$ Emissions. Analysis method in this research is panel GLS model as Lantz and Feng (2006). The results show that the EKC hypothesis did not hold in Korea but there is inverted U relationship between the $CO_2$ Emissions and total factor productivity. As the total factor productivity grows, the $CO_2$ increased but decreased after a certain level.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2010.03a
• /
• pp.44-57
• /
• 2010

The purpose of this paper is to introduce case studies on 2 projects for the construction of port facilities in Colombo, Sri lanka. In Queen Elizabeth quay development project in 2000, the damage at the bottom of steel tubular piles were occurred when piles were driven into subsoil for piled wharf structure in Stage 1. In order to prevent same incident in Stage 2 & 3, the pile driveability analysis were executed by dynamic formulas, analysis program, test driving and pile load tests. Through pile driveability analysis, prevention plans were proposed. In Colombo port expansion project in 2008, the mv method was applied to predict a primary consolidation settlement of a subsoil under a breakwater in the calculation stage. The $m_v$ was estimated from results of cone penetration tests and the final settlement by consolidation was calculated with it.

• Analytical Science and Technology
• /
• v.35 no.6
• /
• pp.249-255
• /
• 2022

In this study, a new method for the analysis of high-purity nitrogen was developed. A gas chromatography-flame ionization detector (GC-FID) was used for purity analysis. Certified reference materials (CRMs) at a level of 3 µmol/mol of carbon monoxide (CO), carbon dioxide (CO₂), and methane (CH₄), which may exist in high-purity nitrogen, were prepared using the gravimetric method, and these CRMs were used for purity analysis. In this new method, ultra-high-purity and high-purity nitrogen were used as carrier gases. The impurities in high-purity nitrogen were quantitatively analyzed by comparing the differences in the area values of the GC chromatograms of the prepared CRMs. We purchased liquid nitrogen and three bottles of nitrogen gas, which were produced by three different manufacturers, using high-purity nitrogen. Furthermore, to validate the developed purity analysis method, the fraction of impurities in high-purity nitrogen was compared with the results of the typical purity analysis method. The comparison results were consistent within the expanded uncertainties (k = 2).

• Genomics & Informatics
• /
• v.21 no.4
• /
• pp.45.1-45.11
• /
• 2023

Nonalcoholic fatty liver disease (NAFLD) is a common type of chronic liver disease, with severity levels ranging from nonalcoholic fatty liver to nonalcoholic steatohepatitis (NASH). The extent of liver fibrosis indicates the severity of NASH and the risk of liver cancer. However, the mechanism underlying NASH development, which is important for early screening and intervention, remains unclear. Weighted gene co-expression network analysis (WGCNA) is a useful method for identifying hub genes and screening specific targets for diseases. In this study, we utilized an mRNA dataset of the liver tissues of patients with NASH and conducted WGCNA for various stages of liver fibrosis. Subsequently, we employed two additional mRNA datasets for validation purposes. Gene set enrichment analysis (GSEA) was conducted to analyze gene function enrichment. Through WGCNA and subsequent analyses, complemented by validation using two additional datasets, we identified five genes (BICC1, C7, EFEMP1, LUM, and STMN2) as hub genes. GSEA analysis indicated that gene sets associated with liver metabolism and cholesterol homeostasis were uniformly downregulated. BICC1, C7, EFEMP1, LUM, and STMN2 were identified as hub genes of NASH, and were all related to liver metabolism, NAFLD, NASH, and related diseases. These hub genes might serve as potential targets for the early screening and treatment of NASH.

• Proceeding of Spring/Autumn Annual Conference of KHA
• /
• 2006.11a
• /
• pp.328-333
• /
• 2006

A few methodologies have been recently developed to estimate the environmental affect when various materials and components are used in building life cycle. The direct survey method has limitations to analyze the environmental problems because of the limit of survey scope and cost. Therefore, another indirect method has been developed as alternatives. The indirect method is represented as input-output analysis. This paper aimed at analyzing the estimation the environmental affect of building materials and works at building construction, utilizing the input-output analysis as a indirect estimation method. The results suggested that the building works is overally responsible for the energy consumption and $CO_2$ emission. In other words, Over the 80% of the total consumption and $CO_2$ emission are resulted at the building work.

• Structural Engineering and Mechanics
• /
• v.2 no.3
• /
• pp.227-244
• /
• 1994

The purpose of this investigation is to propose a numerical simulation method of the crack propagation behavior in 3-dimensionl elastic body. The simulation method is based on the displacement-type finite element method, and the linear fracture theory is introduced. The results from the proposed method are compared with those from the structural experiments, and the good coincidences between them are shown in this paper. At the same time, 2-dimensional analysis is also done, and the results are compared with those obtained from 3-dimensional analysis and the structural experiments.