• 한국연소학회:학술대회논문집
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• 한국연소학회 2015년도 제51회 KOSCO SYMPOSIUM 초록집
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• pp.215-218
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• 2015

Simultaneous laser ignition and spectroscopy is a scheme that enables rapid determination of the local equivalence ratio and condensed fuel concentration during a reaction in a two phase spray flame. We have conducted quantitative analysis of the LIBS signals according to the equivalence ratio, droplet size, droplet number density and droplet concentration as a part of novel feedback control strategy proposed for flame ignition and stabilization with simultaneous in situ combustion flow diagnostics. This is a desirable scheme since such real time information onboard an engine for instance can be constantly monitored and fed back to the control loop to enhance the mixing process and minimize emissions of unwanted species and potential combustion instability.

• International Journal of Reliability and Applications
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• 제2권2호
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• pp.137-146
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• 2001

In general, analysis of the decision problems in nuclear system management involves a simultaneous consideration of various criteria and decision alternatives. Sometimes, it is a complex, unstructured, ill-defined process incorporating the multi-criteria and the data of impreciseness. To cope with this analysis, a fuzzy hierarchical analysis methodology is proposed and demonstrated with a simple example.

• 생약학회지
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• 제51권3호
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• pp.222-229
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• 2020

Recently, consume for functional cosmetics containing natural products has been greatly increased. In order to develop it as a natural cosmetic material, we selected Ixeridium dentatum (Thunb.) Tzvelev, Plantago asiatica L. and Rumex crispus L. that have antioxidant and anti-inflammatory effects. In this study, simultaneous quantitative analysis of the isolated compounds and natural product complexes (Mix.) were validated using high performance liquid chromatography (HPLC). The isolated six compounds were shown in a large linearity with a correlation coefficient (R²) of 0.99. The limit of detection (LOD) of chlorogenic acid, plantamajoside, acteoside, emodin chrysophanol and physcion were 0.36 ㎍/mL, 0.36 ㎍/mL, 0.37 ㎍/mL, 0.30 ㎍/mL, 0.22 ㎍/mL and 0.12 ㎍/mL, respectively. The limit of quantification (LOQ) of chlorogenic acid, plantamajoside, acteoside, emodin chrysophanol and physcion were 1.10 ㎍/mL, 1.08 ㎍/mL, 1.12 ㎍/mL, 0.99 ㎍/mL, 0.66 ㎍/mL and 0.35 ㎍/mL, respectively. Content analysis showed chlorogenic acid (0.19 ± 0.02%), plantamajoside (0.48 ± 0.01%), acteoside (0.65 ± 0.01%), emodin (1.15 ± 0.11%), chrysophanol (0.73 ± 0.01%) and physcion (0.69 ± 0.09%). Therefore, the results of this study may provide for basic data of standardization research natural cosmetic material development on the I. dentatum, P. asiatica and R. cripus.

• 약학회지
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• 제46권4호
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• pp.231-236
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• 2002

A high-performance liquid chromatographic method for the simultaneous quantitative analysis of methylparaben (MP), ethylparaben (EP), propylparaben (PP), butylparaben (BP) and imidazolidinyl urea(IU) or diazolidinyl urea(DU) in cosmetics was studied by using a cyano-propyl column and 0.05M hexanesulfonic acid at 228 nm. Calibration curves were found to be linear in the 60-1000 $\mu\textrm{g}$/mL range (parabens), 100-1,250 $\mu\textrm{g}$/mL range (IU) and the 120-2000 $\mu\textrm{g}$/mL range (DU). 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 commercial cosmetic cream. The precision of this method, calculated as the relative standard deviation (RSD) of the recoveries (0.46-2.71％) was excellent for all compounds.

• Bulletin of the Korean Chemical Society
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• 제21권5호
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• pp.471-476
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• 2000

Liquid chromatography/mass spectrometry with an atmospheric pressure chemical ionization interface (LC/APCI/MS) is evaluated for the simultaneous determination of carbamate pesticides and organophosphorus pesticides in a single chromatographic analysis. APCI mass spectra of those compounds were obtrained to study their ionization characteristics. APCI provided abundant ions such as protonated molecules and characteristic fragment ions for carbamate pesticides and organophosphorus pesticides. To evaluate the feasibility of the LC/APCI/MS for a routine quantitative analysis, the linearity and repeatability of LC/APCI/MS were examined by measuring standard solution mixtures of five carbamate pesticides and four organophosphorus pesticides over the range of 1 to 100 ㎍/mL. Teh peak areas in chromatograms of characteristic ions for those compounds showed less than 3% of variation from run to run. The standard calibration curves for the nine pesticides show good linearity in the concentration range. The detection limits of the LC/APCI/MS system for those compounds range from 0.006 to 0.2 ng.

• Mass Spectrometry Letters
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• 제5권1호
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• pp.30-33
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• 2014

A solid phase extraction (SPE) method was optimized for the quantitative analysis of perfluorooctanoic acid (PFOA) in serum using hydrophilic-lipophilic balance SPE and LC-MS/MS. Fetal bovine serums spiked with $^{13}C_8$-PFOA before or after SPE were used as test samples for evaluation of the SPE efficiency. Simultaneous evaluation of matrix effects and absolute SPE recovery for $^{13}C_8$-PFOA in serum using different sample pre-treatments and SPE conditions allowed optimization of SPE process efficiency with minimal matrix effect and decent SPE recovery. Introduction of protein precipitation as a sample pre-treatment procedure for serum samples before SPE generally decreased matrix effect in LC-MS/MS analysis and provided more stable recovery of PFOA.

• Journal of Advanced Marine Engineering and Technology
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• 제27권3호
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• pp.395-404
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• 2003

Quantitative data of the temperature and velocity were obtained simultaneously by using liquid crystal tracer. PIV(Particle Image Velocimety) based on a grey-level cross-correlation method was used for visualizing and analysis of the flow field. The temperature gradient was obtained by applying the color-image processing to a visualized image, and a neural-network a1gorithm was applied to the color-to-temperature calibration. This simultaneous measurement was applied to the Rayleigh-Bernard convection. This paper describes the method, and presents the quantitative visualization of Rayleigh-Bernard convection and the effect of aspect ratio and viscosity. Also the experimental results were compared with the numerical results.

• 한국수소및신에너지학회논문집
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• 제33권3호
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• pp.232-239
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• 2022

This study performed qualitative and quantitative risk assessment of equipment for evaluating the protocol of hydrogen refueling stations and suggested measures to improve safety. Hazard and operability study was performed for qualitative risk assessment, and Hy-KoRAM was used for quantitative risk assessment. Through a qualitative risk assessment, additional ventilation devices were installed, simultaneous venting of the storage container was prohibited, and the number of repeated refilling of the evaluation equipment was identified to manage the number of fillings of the container. Through quantitative risk assessment, the area around the device was set as a restricted area when evaluating the station, and measures were suggested to reduce the frequency of accidents.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2023년도 임시총회 및 춘계학술대회
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• pp.31-31
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• 2023

Mung bean(Vigna radiata (L.) R. Wilczek var. radiata) is a legume that originated in India. It is the third most cultivated legume in Korea after soybean and adzuki bean. Recently, the use of mung bean seeds and sprouts in trendy foods such as rice noodles and Chinese-style stir-fry is expanding thereby increasing its demand. Subsequently, improvement of mung bean varieties is also being actively conducted. In this study, the important agricultural characteristics of 324 mung bean germplasm were recorded and statistically investigated. Seeds of the mung bean germplasm were cultivated at an experimental field located in the National Agrobiodiversity Center (Jeonju, Korea) and 10 quantitative agricultural traits were investigated. Basic statistics, correlation analysis, and principal component analysis were then performed. The results showed significant variations of the quantitative traits among the germplasms (p < 0.05). The days to flowering, maturity, and growth were in the ranges of 31~80, 22~72, and 57~110 days with means of 45, 47, and 92 days, respectively. The highest frequency (f = 192) was for lodging score with 11~50%, while simultaneous maturity (f = 182) was below 50%. Other quantitative traits related to yield including the number of seeds per pod (CV = 10.9%), number of pods per plant (CV = 41.2%), and one-hundred seeds weight (CV = 36.6%) also showed significant variations. Correlation analysis showed positive correlations between the days to maturity and one-hundred seeds weight (r = 0.41) and the days to growth and simultaneous maturity (r = 0.39). In contrast, one-hundred seeds weight was negatively correlated to the number of pods per plant (r = -0.41) and the days to flowering (r = -0.29). Similarly, the days to growth and the number of pods per plant had a negative association with each other (r = -0.29). The principal component analysis revealed the number of days to maturity as the most influential variable along the first principal component (23.7%). In general, this study revealed wide variations in quantitative traits among the studied mung bean germplasm, which could provide several options for cultivar development.

• 생약학회지
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• 제52권2호
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• pp.112-117
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• 2021

Helianthus annuus L. has been reported with various pharmacological activities such as antibacterial, antidiabetic, and antioxidant effects. According to recent studies, H. annuus L. is known to contain components such as phenolic compounds, flavonoids, alkaloids, sesquiterpenoids, and lignans. The seeds of H. annuus L. have been reported to contain chlorogenic acid and di-O-caffeoylquinic acid as major components. However, studies on the main components and content of leaves of H. annuus L. are still incomplete. Therefore, in this study, the contents of four major components of H. annuus L. were evaluated by simultaneous quantitative analysis with high performance liquid chromatography (HPLC)-diode array detector (DAD). The isolated four compounds Caffeoylquinic acid(CQA), 3,4-dicaffeoylquinic acid(3,4-DCQA), 3,5-dicaffeoylquinic acid(3,5-DCQA) and 4,5-dicaffeoylquinic acid(4,5-DCQA) were shown in a large linearity with a correlation coefficient (R²) of 0.99. In addition, as a result of intra-inter day analysis of four major compounds by the analysis method of this study, the accuracy of 88.46% or more and less than 112.85% and excellent precision of less than 3% were shown, the content analysis showed CQA (0.383±0.018 mg/g), 3,4-DCQA (0.282±0.017 mg/g), 3,5-DCQA (1.109±0.068 mg/g), and 4,5-DCQA (0.673±0.020 mg/g).