• Title/Summary/Keyword: seta

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An Analysis of Detachment Mechanism of Gecko Adhesion System using Finite Element Method (유한요소법을 이용한 게코 접착 시스템의 분리 메커니즘에 대한 해석)

  • Kim, Won-Bae;Cho, Maeng-Hyo
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2010.04a
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    • pp.550-553
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    • 2010
  • 본 논문에서는 seta와 spatula로 구성된 게코(gecko) 접착 시스템의 해석을 위한 새로운 adhesive beam contact model을 제시한다. adhesive contact 해석에 있어서 기존의 JKR model은 nano pillar와 같은 형태의 접촉방식의 해석에는 매우 유용하지만, seta와 같이 보(beam)의 형상을 가지는 구조물의 접촉방식의 해석에는 부적합하다. 따라서 본 연구에서는 seta와 같은 보의 형상을 가지는 접촉 시스템의 해석을 위해 adhesive beam contact model을 제시하고, 유한요소 해석을 통하여 접촉면에서의 불균일한 응력분포 상태가 분리 메커니즘에 미치는 영향에 대한 해석 결과를 제시한다. 또한 spatula의 기하학적 형상과 보의 접촉각(contact angle)등이 seta adhesion system의 분리 메커니즘(detachment mechanism)에 미치는 영향에 대한 결과를 제시한다.

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The Measurement of Flash Point of Water-Methanol and Water-Ethanol Systems Using Seta Flash Closed Cup Tester (Seta Flash 밀폐식 장치를 이용한 Water-Methanol과 Water-Ethanol계의 인화점 측정)

  • Ha, Dong-Myeong;Park, Sang Hun;Lee, Sungjin
    • Fire Science and Engineering
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    • v.29 no.2
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    • pp.39-43
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    • 2015
  • The flash point is the major property to characterize fire and explosion hazard of liquid mixtures. The flash point is the lowest temperature at which a liquid gives off enough vapor to form a flammable air-vapor mixture. The flash points of two aqueous mixtures, water-methanol and water-ethanol, were measured using Seta flash closed cup tester. A prediction method based on activity coefficient models, Wilson and UNIQUAC equations, was used to calculate the flash point. The calculated flash points were compared to the results by the calculating method using Raoult's law. The calculated values based on activity coefficients models were found to be better than those based on the Raoult's law.

Two new species of harpacticoid copepods from anchialine caves in karst area of North Vietnam

  • Tran, Duc Luong;Chang, Cheon-Young
    • Animal cells and systems
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    • v.16 no.1
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    • pp.57-68
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    • 2012
  • Two new harpacticoid species belonging to the genera $Microarthridion$ Lang, 1944 (Tachidiidae) and $Nitocra$ Boeck, 1864 (Ameiridae) are recorded from underground caves in the karst area of Ninh Binh Province, North Vietnam. $Microarthridion$ $thanhi$ n. sp. is distinguished from congeneric species by the number of setae on the antennary exopod, the structure of leg 5 in both sexes, and the finger-like process modified from an outer distal pinnate seta of the third endopodal segment of leg 2 in the male. $Nitocra$ $vietnamensis$ n. sp. has the character combination of six setae on the ellipsoidal exopod of leg 5 in both sexes, the first endopodal segment of leg 1 shorter than the whole exopod, the seta/spine armature of an inner seta of P2-P4 enp-1 and four elements on P2 enp-3, and the reduction of the proximal endite to a seta on the maxillary syncoxa.

Measurement of Flash Points for n-hexanol+n-butyric acid and n-butanol+propionic acid by Seta-flash Closed Cup Method (Seta-flash 밀폐식 방법에 의한 n-hexanol+n-butyric acid 계와 n-butanol+propionic acid 계의 인화점 측정)

  • Ha, Dong-Myeong;Lee, Sungjin
    • Journal of the Korean Society of Safety
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    • v.29 no.6
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    • pp.76-80
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    • 2014
  • The flash point is one of the most important physical properties used to determine the fire hazard of flammable liquid mixture and defined as the lowest temperature at which a liquid produces sufficient vapor to form a combustible mixture with air. The main purpose of this paper is to measure and predict the flash point of binary flammable miscible mixtures. The flash points for n-hexanol+n-butyric acid and n-butanol+propionic acid, were measured by using Seta-flash closed cup method. The experimentally derived data were correlated with the binary interaction parameters of the van Laar and NRTL equations through the optimization method. The flash points estimated by these correlations were compared with those calculated by the method based on Raoult's law. The optimization method were found to be better than the method based on the Raoult's law.

The Calculation and Measurement of Flash Point for Water+1-Propanol and Water+2-Propanol Using Closed Cup Aparatus (밀폐식 장치를 사용한 Water+1-Propanol 과 Water+2-Propanol의 인화점 측정과 계산)

  • Ha, Dong-Myeong;Lee, Sungjin
    • Journal of Energy Engineering
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    • v.25 no.4
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    • pp.190-197
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    • 2016
  • Flash point is the one of the important properties for the safe handling of inflammable liquid solution. In this paper, flash points of binary liquid solutions, water+1-propanol and water+2-propanol, were been measured by using Seta flash closed cup aparatus. Flash point was estimated using regression analysis method. Flash points were also estimated by the method based on Raoul's law and the method optimizing the binary parameters of van Laar equation. Experimental results were compared with the calculated results. The regression analysis method is able to estimate the flash point fairly well for water+1-propanol and water+2-propanol mixture.

Flash Point Measurement of n-Propanol+n-Hexanol and n-Butanol+n-Hexanol Systems Using Seta Flash Closed Cup Tester (Seta Flash 밀폐식 장치를 이용한 n-Propanol+n-Hexanol계와 n-Butanol+n-Hexanol계의 인화점 측정)

  • Ha, Dong-Myeong;Lee, Sungjin
    • Journal of the Korean Society of Safety
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    • v.34 no.1
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    • pp.34-39
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    • 2019
  • Flash point is the important indicator to determine fire and explosion hazards of liquid solutions. In this study, flash points of n-propanol+n-hexanol and n-butanol+n-hexanol systems were obtained by Seta flash tester. The methods based on UNIFAC equation and multiple regression analysis were used to calculate flash point. The calculated flash point was compared with the experimental flash point. Absolute average errors of flash points calculated by UNIFAC equation are $2.9^{\circ}C$ and $0.6^{\circ}C$ for n-propanol+n-hexanol and n-butanol+n-hexanol, respectively. Absolute average errors of flash points calculated by multiple regression analysis are $0.5^{\circ}C$ and $0.2^{\circ}C$ for n-propanol+ n-hexanol and n-butanol+n-hexanol, respectively. As can be seen from AAE, the values calculated by multiple regression analysis are noticed to be better than the values by the method based on UNIFAC eauation.

Determination of Flash Point for n-Octane+n-Nonane and n-Nonane+n-Decane Systems by Seta flash Apparatus (Seta flash 장치에 의한 n-Octane + n-Nonane계 및 n-Nonane + n-Decane계의 인화점 결정)

  • Ha, Dong-Myeong;Lee, Sungjin
    • Journal of the Korean Institute of Gas
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    • v.24 no.6
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    • pp.11-17
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    • 2020
  • In order to guarantee safe storage and transportation of a flammable liquid solution, it is very important to know its flash point information. In this paper, flash points of n-octane+n-nonane system and n-nonane+n-decane system were measured by Seta flash apparatus and an empirical equation is proposed for the accurate estimation of flash point. Empirical equation is used to predict flash point of n-octane+n-nonane system and n-nonane+n-decane system, which were also compared to Unifac-based model. Absolute average errors of flash point data predicted by Unifac-based model are 0.7℃ and 0.6℃ for n-octane+n-nonane system and n-nonane+n-decane system, respectively. Absolute average errors of flash point data predicted by empirical equation are 0.2℃ and 0.4℃ for n-octane+n-nonane system and n-nonane+n-decane system, respectively. In conclusion, empirical equation proposed in this paper, presented the most satisfactory.

Three new species of Myzomolgus(Copepoda, Cyclopoida, Catiniidae) associated with sipunculan worms from a tidal flat in Phuket, Thailand

  • Hong, Jae-Sang;Kim, Il-Hoi
    • Journal of Species Research
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    • v.10 no.3
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    • pp.287-300
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    • 2021
  • Three new species of Myzomolgus are described as associates of sipunculans from a tidal flat in Phuket, Thailand. As diagnostic features, Myzomolgus leptocercosus n. sp. has elongate caudal rami which are 10.7 times longer than wide, 5 setae and a conical process on the first antennular segment, an armature formula 1, 0, 1+sucker, and 6 of antenna, and an inner coxal seta on all swimming legs. Myzomolgus spatulatus n. sp. lacks a rostrum, but bears 4 setae and a spatulate process on the first antennular segment, an armature formula 0, 0, 2+sucker, and 6 of the antenna, the inner coxal seta on legs 1-3, and 5 armture elements on the third endopodal segment of legs 1-3. Myzomolgus cucullatus n. sp. has short caudal rami which are 1.60 times longer than wide, a broad, hood-like tergite of fouth pedigerous somite, 4 setae only on the first antennular segment, the armature formula 0. 0. 2+sucker, and 6 of the antenna, and no iiner coxal seta on the swimming legs.

Measurement of Flash Point for Binary Mixtures of Toluene, Methylcyclohexane, n-heptane and Ethylbenzene at 101.3 kPa (Toluene, Methylcyclohexane, n-heptane 그리고 Ethylbenzene 이성분 혼합계에 대한 101.3 kPa에서의 인화점 측정)

  • Hwang, In Chan;In, Se Jin
    • Fire Science and Engineering
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    • v.31 no.3
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    • pp.19-24
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    • 2017
  • Flammable substances are used in laboratories and industrial process. The flash point (FP) is one of the most important physical properties used to determine the potential for characterizing the fire and explosion hazard of liquids. The FP data at 101.3 kPa were measured for the binary systems {toluene+ethylbenzene}, {methlycyclohenxane+ethylbenzene} and {n-heptane+ ethylbenzene}. The experiments were performed according to the standard test method (ASTM D 3278) using a SETA closed cup flash point tester. The measured FPs were compared with the values predicted using the following activity coefficient models: Wilson, Non-Random Two Liquid (NRTL), and UNIversal QUAsiChemical (UNIQUAC). The average absolute deviation between the predicted and measured lower FP was less than 1.74 K.

Experimental Determination of Closed Cup Flash Point of Binary Flammable Solutions, 2-Propanol+Propionic acid and n-Hexanol+Formic Acid Solutions (가연성 이성분계 용액인 2-Propanol+Propionic acid 와 n-Hexanol+Formic acid 용액의 밀폐식 인화점의 실험적 결정)

  • Ha, Dong-Myeong;Lee, Sungjin
    • Journal of the Korean Institute of Gas
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    • v.19 no.3
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    • pp.18-24
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    • 2015
  • The flash point is one of the most important indicators of the flammabiliy of liquid solutions. The flash point is the lowest temperature at which there is enough concentration of flammable vapor to form an ignitable mixture with air. In this study the flash points of binary flammable solutions, 2-propanol+propionic acid and n-hexanol+formic acid systems, were measured using Seta flash closed cup tester. Particularly n-hexanol+formic acid system exhibited minimum flash point behavior. The measured values were compared with the calculated values using Raoult's law and optimization method. The calculated data by optimization method described the measured values more effectively than those calculated by Raoult's law.