• Title/Summary/Keyword: stability test

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Wind tunnel test research on aerodynamic means of the ZG Bridge

  • He, Xiangdong;Xi, Shaozhong
    • Wind and Structures
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    • v.2 no.2
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    • pp.119-125
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    • 1999
  • The ZG Bridge(preliminary design), with unfavorable aerodynamic stability characteristics, is a truss-stiffened suspension bridge, its critical wind speed of flutter instability is much lower than that of code requirement, In the present paper, based on both aerostatic and aeroelastic section model wind tunnel test, not only effects of some aerodynamic means on aerodynamic stability of its main girder are investigated, but also such effective aerodynamic means of it as flap and plate-like center stabilizer are concluded.

Evaluation on the Safety of ${\gamma}$-Irradiated Angelica gigas Nakai: Stability of Active Components and Safety in Genotoxicity Test (감마선 조사 당귀(Angelica gigas Nakai)의 유효성분 안정성 및 유전독성학적 안전성 연구)

  • 조성기;유영법
    • 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.

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Study on animal Ocular irritation test of ozonated olive oil (오존화 올리브오일의 동물 눈 안점막 자극시험 연구)

  • Kim, Duck-Sool
    • Journal of the Korean Applied Science and Technology
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    • v.35 no.4
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    • pp.1407-1412
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    • 2018
  • This study suggests that ozonated olive oil can kill a wide variety of microorganisms while being less toxic but in the case of administration or abdominal administration, the human body is harmless. In Korea, there is no animal stability test yet. In this study, ozonated olive oil was used to test the stability of the animal through the eye. Specific experiments were performed to evaluate animal Ocular irritation safe test of ozonized oil (high concentration) in rabbits. and Observation of the treatment point on the test substance, ozonated olive oil showed no Ocular irritation in both the non-washing group and the washing group.

FORMULATION AND STABILITY TEST OF ANTIAGING CREAM CONTAINING METHANOL FRACTION OIL OF PANGIUM EDULE.REINW. AS A RADICAL SCAVENGER AGENT

  • Djajadisastra, J.;Anwar, E.;Milani, E.
    • Proceedings of the SCSK Conference
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    • 2003.09b
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    • pp.303-306
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    • 2003
  • Indonesia is a tropical country having a temperature range of 25-35$^{\circ}C$ which can affect the skin and causes damages like aging. This aging process is due, at least, to free radical reactions. For this reason, many attempts had been done to find out creams containing natural antioxidant compound which have a potential of free radical scavenger. Kluwek, a fermented form of foot ball fruit or picung (Pangium edule.Reinw), had been proved to contain antioxidant compound in its methanol fraction oil to which antiaging cream was formulated. Stability evaluation was conducted for cream with Kluwek oil compared to base cream, including organoleptic (colour and odour), pH, viscosity, particle size, centrifugation test and flow characteristics either in room temperature (27$^{\circ}C$) or stress condition (4$^{\circ}C$ and 5$0^{\circ}C$) for 8 weeks continuously, and six times cycling test at 4$^{\circ}C$ and 5$0^{\circ}C$ every 24 hours. The results showed that cream with Kluwek oil and base cream were stable at temperature 27 and 4$^{\circ}C$, cycling test and centrifugation test, but not stable at 5$0^{\circ}C$. Free radical evaluation was done by Electron Spin Resonance and the result showed that cream with Kluwek oil had less free radicals compared to base cream.

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Experiments on Development A Pulse-Gun Pressure-Wave Inducing Device for Stability Rating Test Technique (연소안정성 평가시험 기법을 위한 펄스건 압력파 유도장치 개발 실험)

  • Lee, Kwang-Jin;Kim, Hong-Jip;Seo, Seong-Hyeon;Moon, Il-Yoon;Kim, Hyung-Mo;Lee, Soo-Yong;Ko, Young-Sung
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.33 no.3
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    • pp.99-106
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    • 2005
  • The SRT(stability rating test) technique, which is indispensable for the development of a LRE(liquid rocket engine), essentially requires a development of a combustion test sequence as well as artificial perturbation devices. For the development of an indigenous SRT technique, several combustion tests of sub-scale LRE were performed to search a proper combustion test sequence. At first, a pressure-wave inducing device which is used for adapting pulse gun was designed and a cooling gas supply system for the pressure-wave inducing device was set up to prevent a malfunction of pulse gun. Through the several combustion tests which included cooling procedure of a pressure-wave inducing device, a proper combustion test sequence was found out. It did not make any significant disturbance at normal combustion process. Finally, an indigenous SRT technique has been developed successfully.

Captive Model Test of Submerged Body Using CPMC (몰수체의 CPMC 구속모형시험)

  • Kim, Yeon-Gyu;Yun, Kun-Hang;Kim, Sun-Young;Kim, Dong-Jin
    • Journal of the Society of Naval Architects of Korea
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    • v.49 no.4
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    • pp.296-303
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    • 2012
  • The captive model test of submerged body using CPMC(Computerized Planar Motion Carriage) was carried out at the Ocean Basin of KORDI/MOERI. The target model is a submarine with general hullform. The forces and moments acting on the submerged body were measured by 6-axis waterproof gage. The oblique motion test and turning test were carried out in horizontal and vertical planes of the model. Maneuvering coefficients and derivatives were obtained from the test results. The stability indices in horizontal and vertical planes were obtained by using maneuvering derivatives. In this paper the introduction of test equipment and test results are presented.

An Experimental Assesment of Combustion Stability of Coaxial Swirl Injector and Impinging Injector through Simulating Combustion Test (상압기상연소시험을 통한 동축형 스월 분사기와 충돌형 분사기의 연소안정성 평가)

  • Park, Junhyeong;Kim, Hongjip
    • 한국연소학회:학술대회논문집
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    • 2014.11a
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    • pp.153-156
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    • 2014
  • This study was aimed to assess combustion stability for coaxial swirl injector and FOOF impinging injector which would be candidates in liquid rocket engine combustors. Simulating combustion tests under atmospheric condition have been conducted by gaseous oxygen and the mixture of methane and propane, using two actual injectors. By analyzing the measured dynamic pressure signals, we have evaluated the combustion stability margin of both injectors by drawing a stability map.

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Schur Stability of Complex Polynomials (복소다항식의 Schur 안정성)

  • Choo, Youn-Seok;Kim, Dong-Min
    • Journal of Institute of Control, Robotics and Systems
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    • v.15 no.7
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    • pp.671-674
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    • 2009
  • Determining the Schur stability of a polynomial is one of fundamental steps in many engineering problems including digital control system design or digital filter design. Due to its importance a variety of techniques have been reported in the literature for checking the Schur stability of a given polynomial. However most of them focus on real polynomials, and few results are available for complex polynomials. This paper concerns the Schur stability of complex polynomials. A simplified Jury's table for real polynomials is extended to complex polynomials.

Effects of Using a Mobile Phone on Postural Control (휴대전화 이용이 자세조절에 미치는 영향)

  • Won, Jong-Im
    • Physical Therapy Korea
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    • v.19 no.3
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    • pp.61-71
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    • 2012
  • In daily activities, people often perform two or more tasks simultaneously. This is referred to as dual-tasking or multi-tasking. The purpose of this study was to examine the effects of performing dual tasks while using a mobile phone on static and dynamic postural stability. Twenty-four subjects were asked to stand on a force plate and then instructed to perform a balance task only (BT), a balance task while listening to music (BTL), a balance task while talking on the mobile phone (BTT), and a balance task while sending text messages (BTS). We used the BioRescue$^{(R)}$ to measure postural sway and limit of stability for static and dynamic postural stability. Also the star excursion balance test (SEBT) was used to measure dynamic postural stability. A one-way ANOVA with repeated measures was used to compare the effects of the BT, BTL, BTT, and BTS. The Bonferroni's post hoc test was used to determine the differences among four tasks. Carrying out the BTS significantly decreased the limit of stability compared with carrying out the BT, BTL, and BTT (p<.05). In limit of stability, total surface area of BTT was more significantly decreased than that of BT and total surface area of BTS was more decreased than that of BT, BTL and BTT (p<.05). In the SEBT, the BTS displayed significantly smaller reach distance values compared with the BT or BTL (p<.05). These findings suggest that performing the balance task while sending text message on the mobile phone decreases dynamic postural stability, whereas performing the same task while listening to music using the mobile phone does not. Therefore, it requires more attention to maintain dynamic balance while sending text messages.

Evaluation of Homogeneity and Stability of Korean Mussel (Mytilus coruscus) Standards for Cadmium Analysis (카드뮴 분석용 홍합(Mytilus coruscus) 표준물질의 균질성 및 안정성 시험평가)

  • Lee, Ha-Eun;Lee, Jangho;Chung, David;Lee, Soo Yong;Park, Ki-Wan;Shim, Kyu-Young
    • Journal of Environmental Science International
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    • v.28 no.11
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    • pp.1041-1045
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    • 2019
  • In this study, the KS A ISO Guide 35 was applied to develop analytical standards for heavy metal cadmium using the Korean mussel (Mytilus coruscus) and to evaluate the homogeneity and stability of the sample. Some of the crucial characteristics that reference materials must consist include homogeneity and stability of both intra- and inter-bottles. We tested homogeneity using ANOVA analysis and short-term stability using regression analysis. The variations of cadmium concentrations did not significantly differ between intra- and inter-bottles (F=0.41, p=0.90). For short-term stability verification, cadmium analysis results were not statistically significant as a result of the regression analysis (significance F=0.51, p=0.53). This suggests that we can not dismiss the null hypothesis that there is no significant variation in concentrations of cadmium over time. These results indicated that the cryogenic-milling process has statistically proven the short-term stability for materials from mussels in the chemical analysis of cadmium. Therefore, we propose that the Korean mussel's reference material developed for the proficiency test could be used as a tool to evaluate reliability and consistency in laboratories.