• Analytical Science and Technology
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• v.33 no.3
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• pp.125-133
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• 2020

Methylisothiazolinone (MIT) and chloromethylisothiazolinone (CMIT) cause allergic contact dermatitis and are banned cosmetics ingredients, except in rinse-off products. However, their presence has been detected in cosmetics. We report a UPLC-tandem MS/MS screening method for their simultaneous determination in cosmetics. To facilitate extraction from various matrices, pretreatment methods were developed for each sample type. The method was optimized through a series of assessments, including specificity, LOD, LOQ, linearity, recovery, stability, precision, and accuracy. The LODs and LOQs for MIT ranged from 0.054 and 0.163 ㎍ mL^-1 whereas those for CMIT ranged from 0.040 and 0.119 ㎍ mL^-1. The linear correlation coefficients (r²) were higher than 0.999. Relative standard deviations (RSDs) for both intra- and inter-day measurements ranged from 0.3 ~ 13.6 %. Recoveries at three different concentrations were within 87.9 ~ 118.9 %. The RSD for stability measurements of spiked samples was within 7 %. These results confirm the suitability of the developed method for the simultaneous quantitation of MIT and CMIT in cosmetics. Samples of 320 color cosmetics, including eyeshadows, solid lipsticks, liquid lipsticks, and nail polishes were analyzed using the developed method, and two of them were found to contain both MIT and CMIT and one of them was found to contain only MIT. This data and the method will aid the regulation of ingredients used in cosmetics.

• Journal of the Korea Institute of Military Science and Technology
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• v.20 no.1
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• pp.1-11
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• 2017

In this paper, design requirements of the large radar were investigated, and development was performed through the analysis and design. Large radar should be designed by bearing the 75 knot wind force and $20kg/m^2$ ice mass as operating conditions in order to meet structural stability, and driving torque and bearing load were calculated for securing the driving stability. Thermal dissipation analysis was performed considering TRM and DC-DC Converter's limitation temperature by $50^{\circ}C$ ambient temperature condition in order to attain thermal stability, and PSD and shock analysis were carried out by using MIL-STD-810G vibration and shock specification in order to transport and installation of the large radar. As a result, all components of large radar could secure the structural stability more than 2.8 factor of safety, and driving stability was also secured with adequate bearing fatigue life. Thermal stability was attained by allowable max temperature 88.7 C of the TRM, and structural stability for transportation and installation of the large radar was also secured more than 5 factor of safety. After it was transported and installed to the radar site, operating capability was finally verified by rotating the large radar.

• Herbal Formula Science
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• v.24 no.2
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• pp.71-79
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• 2016

Objectives : To verify the equivalence between Atractylodis Rhizoma Alba herbal prescription(HP-ARA) and Atractylodis Rhizoma Alba herbal sub stance(HS-ARA). Methods : Safety tests by microbial regulation and heavy metal analysis (total heavy metal, Pb, As) and a stability test by long term shelf test for HP-ARA according to notification of the Ministry of Food and Drug Safety were carried out. Then, multi component profile of HP-ARA and HS -ARA were analyzed by HPLC. Results : The safety and stability of HP-ARA confirmed by several tests. Correlation coefficient of equivalence of HP-ARA and ARA-HS showed 0.992. Conclusion : Based on this result of equivalence between HP-ARA and HS-ARA, HP-ARA can substitute HS-ARA used to make herbal medicines (herbal decoction, pills and powder).

• Geomechanics and Engineering
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• v.14 no.1
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• pp.71-81
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• 2018

Soils are mostly nonhomogeneous and anisotropic in nature. In this study, nonhomogeneity and anisotropy of soil are taken into consideration by assuming that the cohesion increases with depth linearly and also varies with respect to direction at a particular point. A three-dimensional rotational failure mechanism is adopted, and then a three-dimensional stability analysis of slope is carried out with the failure surface in the shape of a curvilinear cone in virtue of the limit analysis method. A quasistatic approach is used to develop stability charts in nonhomogeneous and anisotropic soils. One can easily read the safety factors from the charts without the need for iterative procedures for safety factors calculation. The charts are of practical importance to prevent a plane failure in excavation slope whether it is physically constrained or not. Then the most suitable location of piles within the reinforced slope in nonhomogeneous and anisotropic soils is explored, as well as the interactions of nonhomogeneous and anisotropic coefficients on pile reinforcement effects. The results indicate that piles are more effective when they are located between the middle and the crest of the slope, and the nonhomogeneous coefficient as well as the anisotropic coefficient will not only influence the most suitable location for piles but also affect the calculated safety factor of existing reinforced slope. In addition, the two coefficients will interact with each other on the effect on slope reinforcement.

• Journal of Korean Medicine Rehabilitation
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• v.19 no.1
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• pp.187-199
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• 2009

Objectives : The electroacupuncture was generally has been used in oriental medicine doctors. In recent years, there have been a few studies about safety and stability of acupuncture needle in itself, but then again research of acupuncture needle safety and stability on applying electroacupuncture have been insignificant. Therefore we investigated the safety and change in mechanical characteristic of acupuncture needle in electroacupuncture therapy. Methods : We observed mechanical characteristic change by SEM(Scanning Electron Microscope) and EDX(Energy Dispersive X-ray Spectroscopy), evaluated the hardness by vickers hardness tester. We used MTT assay and cell stain to study about biocompatibility of electroacupuncture. Results : In this study, any corrosion of material, alternation of elements, and change of hardness were not observed in surface analysis using SEM and EDX. In cytotoxity evaluation using MTT assay and cell stain, cell survival rate was low when practicing the electroacupuncture for more than 3 hours. Conclusions : Change of mechanical property was not observed based on the test results using surface analysis and hardness estimation by the electroacupuncture. And considering the biocompatibility, electroacupuncture was thought to be safe in an hour based on cytotoxity evaluation using MTT assay and cell stain.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.2
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• pp.300-306
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• 2000

In the present studies, we assessed the stability of active components and toxicological safety of irradiated Angelica gigas Nakai(Danggui). In order to confirm the stability of active components in the ${\gamma}$-irradiated roots of Danggui, the quantitative analysis of decursin and decursinol angelate of ${\gamma}$-irradiated sample was carried out by high performance liquid chromatographic (HPLC) methods using reverse phase columns and normal phase columns. From the root of Danggui, decursin and decursinol angelate were isolated by a silica gel column chromatography(toluene : ether (1 : 1), Hexane : EtOAc(15 : 1)). And then the structures were confirmed in the 1H and 13C-NMR analysis. The HPLC chromatograms of decursin and decursinol angelate in ${\gamma}$-irradiated Danggui were similar with those of non-irradiated sample. In the examination of in vitro genotoxicity of the water extract from ${\gamma}$-irradiated Danggui using Salmonella reversion assay(Ames test) and micronucleus test in Chinese hamster ovary (CHO) cells, mutagenicity was not exhibited in the two assays with or without metabolic activation. These resutls suggest that active components in the ${\gamma}$-irradiated Danggui should be stable and that the safety of ${\gamma}$-irradiated Danggui could be revealed in further test in vivo.

• Journal of the Society of Naval Architects of Korea
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• v.40 no.6
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• pp.30-36
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• 2003

To improve survivability of damaged ship, assessment of stability and structural safety, and behavior analysis in wave is required. Prediction of sinking time, damage stability and structural strength considering progressive flooding and dynamic force in wave is very important. To do it, a geometric model which can be express damaged ship is prepared. This paper described the geometric modeler for survivability assessment of damaged ship. The modeler is developed based on 3-D geometric modeling kernel, ACIS. The hull form and compartment definition is available fundamentally. And requirement for modeler contains data generation and interface for hydrostatic calculation, behavior analysis, and longitudinal strength analysis and so on. To easy access modeling system by conventional user such as crew, user interface is developing.

• Journal of the Korean Geotechnical Society
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• v.18 no.5
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• pp.271-280
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• 2002

A probabilistic approach to identify the effects of uncertainties of soil strength parameters on searching a critical slip surface with the lowest reliability is introduced. In general construction field, it is impossible for the engineer to always gather a variety of statistical information of soil strength parameters for which lots of laboratory and in-situ soil testing are required and to use it with enough statistical knowledge. Thus, in order that the engineer may easily understand the probabilistic concept for the slope stability analysis, this study proposes a combined procedure to incorporate the engineering probabilistic tools into the existing deterministic slope stability analysis methods. Using UTEXAS 3, a slope stability analysis computer program developed by U.S. Army Corps of Engineers (U.S. COE), this study provides the results of this probabilistic slope stability analysis in terms of probability of failure or reliability index. This probabilistic method f3r slope stability analysis appears to yield more comprehensive results of slope reliability than does existing deterministic methods with safety factors alone.

• Journal of Power System Engineering
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• v.14 no.3
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• pp.71-76
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• 2010

The safety block which prevents drop of laborers at high altitude was analyzed by finite element method. Elastic analysis was done by Ansys ver. 11.0. and tetrahedral meshing was used. As load applied more vertically at the fixed face of saw tooth, the stress concentration became smaller and the load distributed broader. When load worked at saw tooth and the shape was more straight to the direction of load, most stresses except principal stress became smaller. When the area of the load increased, principal stress and equivalent stress could be decreased simultaneously. A principal stress and other various stresses occurred in 3D shape, therefore revised model which has smaller equivalent stress than other models shows excellence on the stability and the credibility.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.904-909
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• 2008

Most of current slope safety analysis consider only the effect of the rise of underground water level. However, because the infiltration of surface water into the ground is believed to have signification effect on slope stability, the present study performed slope safety analysis in case of the rise of underground water level, infiltration of surface water, and both resulting from rainfall, and examined their effect.