• Title/Summary/Keyword: Water Vapour

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A Study on Vapour Explosion Caused by the Contact Between Molten Salt of Na$_2$CO$_3$-NaOH Mixture and water (Na$_2$CO$_3$-NaOH 혼합용융염과 물의 접촉에 의한 증기폭발에 관한 연구)

  • Mok, Yun-Soo;Chiaki Ogiso;Yoichi Uehara
    • Journal of the Korean Society of Safety
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    • v.4 no.1
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    • pp.41-46
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    • 1989
  • Molten salt-water explosion caused by the contact between molten salt and water is one of vapour explosions. An experimental study of the vapour explosion, which occurs when the molten mixture of Na$_2$CO$_3$-NaOH and water come in contact was performed. The pressure wave generated in each composition Of molten mixtures was measured. The results obtained are as follows: 1) The vapour explosion didn't occur for a molten salt of 100%-Na$_2$CO$_3$- 2) For a molten salt of Na$_2$CO$_3$ 80%-NaOH 20% mixture, a small vapour explosion occured initially, and a large vapour explosion, which showed the largest pressure wave among the present experiments, occurred after an induced period. 3) For molten salt of Na$_2$CO$_3$60% - NaOH 40% mixture and Na$_2$CO$_3$ 40% - NaOH 60% mixture, the vapour explosion occurred near the water surface shortly after they come in contact with water. This explosion would be caused by fragmentation of the molten salts due to impulse generated when thee molten salts and water come in contact.

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Change of Porosity and Water Vapour Transport Properties of Wool Fabrics by the Change of Moisture Regain and Fabric Structure (모직물의 수분율 변화와 구조에 따른 기공도 및 수분전달 특성변화)

  • 김동옥;나미희;김은애
    • Journal of the Korean Society of Clothing and Textiles
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    • v.23 no.6
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    • pp.820-828
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    • 1999
  • The purpose of this study was to investigate the changes of pore area and water vapour transport by the changes of moisture regain and fabric structure of wool fabrics, As specimens 4 worsted wool fabrics were used. The pore area were measured by image analysis method and dinamic vapour transport and water reisitance was determined by clothing-environment-body modelling system. The pore area was changed by the moisture regain of wool fabrics. The change of pore area was influenced by the yarn twist thread count and cover factor and the weave type. The water vapour transport was changed by the moisture regain. The change of water vapour transport was influenced by the change of pore aree which was determined by image analysis.

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The Water Vapour Transfer on Outdoor Activities Clothing (야외 운동복에서의 수분전달)

  • Oh, Ae-Gyeong
    • Proceedings of the Korean Fiber Society Conference
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    • 2001.10a
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    • pp.115-118
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    • 2001
  • The water vapour permeability of clothing materials is a critical property for clothing systems that must maintain thermal equilibrium for the wearer. The evaporation of perspiration provides the means of cooling the human body. The perspiration should evaporate from the surface of the skin and pass as water vapour through the clothing, which must be permeable for comfort. The primary objectives in this study of the transfer through fabrics of water vapour are to measure this property in a quantitative manner appropriate to clothing systems and to provide an increased understanding of various types of fabric in water vapour transfer. (omitted)

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Evaluation Method for the Water Transport Properties of Sweat Absorbent Fabrics - Water Vapour Transport in the of Human-Clothing-Environment System - (첨단 흡수속건소재의 수분전달 특성 평가방법에 관한 연구 - 인체-의복-환경 System에서의 투습성 평가 -)

  • Kim, Eun Ae;Barker, Roger L.
    • Journal of the Korean Society of Clothing and Textiles
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    • v.17 no.2
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    • pp.329-338
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    • 1993
  • The purpose of this study was to design an instrument to simulate the Human-Clothing-Environment system and evaluate the water vapour transport properties of sweat absorbent PET fabrics. The instrument was composed of sweat generating part, clothing part which can simulate clothing layers, and enviromental part. As specimens, sweat absorbent PET, regular PET, cotton, nylon and acrylics fabrics were included. For the water vapour transport(WVT), relative humidities and temperatures were measured by film type humidity sensors and thermocouples, respectively. Water vapour pressures were calculated with measured RH's and temperatures. For the liquid water transport, wickability and demand wettability were measured. Results showed that there was a difference in terms of water vapour transport mechanism depending on the fiber type ; sweat absorbent PET showed higher WVT at the transient period then equilibrated, whereas other fabrics showed lower WVT at the transient period then increased continuously. These differences are expected to affect to the difference in the comfort properties of clothings. Sweat absorbent PET showed higher demand wettability and wickability than other fabrics. Wide application of the instrument was also suggested.

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The impact of corrosion on marine vapour recovery systems by VOC generated from ships

  • Choi, Yoo Youl;Lee, Seok Hee;Park, Jae-Cheul;Choi, Doo Jin;Yoon, Young Soo
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.11 no.1
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    • pp.52-58
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    • 2019
  • Marine emissions of Volatile Organic Compounds (VOCs) have received much attention because the International Maritime Organization (IMO) requires the installation of vapour emission control systems for the loading of crude oils or petroleum products onto ships. It was recently recognised that significant corrosion occurs inside these vapour emission control systems, which can cause severe clogging issues. In this study, we analysed the chemical composition of drain water sampled from currently operating systems to investigate the primary causes of corrosion in vapour recovery systems. Immersion and electrochemical tests were conducted under simulated conditions with various real drain water samples, and the impact of corrosion on the marine vapour recovery system was carefully investigated. Moreover, corrosion tests on alternative materials were conducted to begin identifying appropriate substitutes. Thermodynamic calculations showed the effects of environmental factors on the production of condensed sulphuric acid from VOC gas. A model of sulphuric acid formation and accumulation by the characteristics of VOC from crude oil and flue gas is suggested.

The Generation of Vacuum Scale Using the Vapour Pressure of Water (물의 증기압을 이용한 진공도눈금의 생성)

  • Seong D. J.;Shin Y. H.;Chung K. H.
    • Journal of the Korean Vacuum Society
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    • v.14 no.4
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    • pp.180-185
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    • 2005
  • The possibility of generation of the vacuum scale using the vapour pressure of water was evaluated. The range of vacuum from 3.3 kPa to 101.3 kPa was corresponds the vapour pressure of water in the temperature range from $25^{\circ}C$ to $100^{\circ}C$ The measured values of the vapour pressure of water were agreed within the deviation of $5\%$ comparing to reference value. This result shows the vapour pressure of water can be used as an secondary reference of the vacuum scale. Moreover it shows the thermo-dynamical properties such as, triple point, temperature-pressure curve of a material have a applicability in the vacuum scale as a reference in corresponding range of vacuum.

PREPARATION OF HYDROXYAPATITE COATINGS USING R.F. MAGNETRON SPUTTERING

  • Hosoya, Satoru;Sakamoto, Yukihiro;Hashimoto, Kazuaki;Takaya, Matsufumi;Toda, Yoshitomo
    • Journal of the Korean institute of surface engineering
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    • v.32 no.3
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    • pp.307-311
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    • 1999
  • The well-crystalline hydroxyapatite($Ca_{10}(PO_4)_6(OH)_2$ ; HAp) layer having a biocompatibility was successfully coated onto titanium substrate using a radio-frequency magnetron sputtering, and effects of sputtering gas and the thickness of HAp film on a crystal growth of the HAp layers were investigated. The deposition rate of the layer sputtered with water-vapour gas was slower than that of the layer sputtered with argon gas. The results of X-ray diffraction demonstrated that the about $0.8\mu\textrm{m}$ thick HAp film under water-vapour gas was an amorphous phase, the about $1.2\mu\textrm{m}$ thick film was (100) plane-oriented HAp, and the about $1.5\mu\textrm{m}$ thick film was (001)plane-oriented HAp. FT-IR analysis proved that hydroxyl group of the layer sputtered with argon gas was defected, but that of the layer sputtered with water-vapour gas was not defected. From these results, it was favorable to use water-vapour gas on the HAp coatings onto metal surface.

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Performance Evaluation of Water Vapour Adsorption/Desorption Property for a Building Material by Mock up Test (실물시험을 통한 흡방습 건축자재의 성능평가)

  • Kim, Hea Jeong;Song, Kyoo Dong;Lee, Yun Gyu
    • KIEAE Journal
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    • v.9 no.2
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    • pp.53-58
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    • 2009
  • There are increasing developments and uses of functional building materials are recently developed and introduced to the test method for the materials. Especially, moisture problem has a major role are also being established in indoor air quality problems. The purpose of this study is to evaluate the water vapour adsorption/desorption property of a ceiling material. The variation of the temperature and moisture were measured with the application materials by mock up test based on JIS 1470-1. The result shows that water vapour adsorption/desorption property of ceiling material is appeared in changes of moisture adsorption and desorption in comparison with that of a general ceiling material. Therefore, in case of decreasing and increasing in humidity, these materials can be used as an finishing material to sustain comfort condition.

A Study on the Improvery Efficiency of Heavy Water Vapour for CANDU Reactor Systems (CANDU형 원자력 발전소의 중수 증기 회수율 증대 방안에 관한 연구)

  • 김윤제;박이동;황영규;이도영
    • Proceedings of the Korea Society for Energy Engineering kosee Conference
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    • 1995.05a
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    • pp.101-112
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    • 1995
  • In order to improve the recovery efficiency of heavy water vapour from the atmosphere inside a reactor building, and to recover and upgrade the heavy water which escape, special treatments, such as reducing the ingress of light water vapour, are studied in the design of the CANDU reactor systems. This is considered in controlled method of the humidity over drawing fresh air through a desiccant dehumidifier which dries the air by absorption. Comparing with the moisture loads between summer and winter operations, the moisture removal rates are calculated. Those are proportional to the difference between the controlled space and the surrounding environment Installation of a new dehumidifier will be able to reduce the moisture loads from the cooling systems, improving overall system efficiency and saving operating costs.

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Preparation of Porous Cordierite by Using Water-Vapour Treatment (수증기처리공정에 의한 다공성 코디어라이트의 제조)

  • 문교태;서신석;노재성;조득희;김동표
    • Journal of the Korean Ceramic Society
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    • v.34 no.9
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    • pp.986-992
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    • 1997
  • Cordierite ceramic was prepared by sol-gel method. It was analyzed by Infrared spectroscopy and X-ray diffraction patterns that the ceramic was chemically mixed in molecular level and transformed to $\alpha$-cordierite at 125$0^{\circ}C$. Water vapour treatments for aging and drying process were conducted to get porous cordierite with thermally stable pore structure. It resulted in 220-410 $m^2$/g BET surface area and mesoporous structure with mean pore diameter, 40$\AA$. Compared to naturally dried ceramic, the ceramic showed superior thermal stability of surface area up to $700^{\circ}C$. Surfaces of porous cordierite ceramics were observed by SEM.

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