• Title/Summary/Keyword: wet-dry

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The Effects of Drawing Conditions on Physical Properties of the Drawn Worsted Yarns (II) (연신공정 조건이 소모연신사의 물성에 미치는 영향 (II))

  • Han, Won-Hee;Kim, Seung-Jin;Jo, Jin-Hwang
    • Textile Coloration and Finishing
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    • v.22 no.1
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    • pp.61-70
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    • 2010
  • This effects of drawing conditions on the physical properties of the drawn worsted yarns were investigated. The drawn worsted yarns were made on the yarn drawing system with various drawing conditions such as concentration of reducing agent, draw ratio, setting time of drawn yarn and concentration of oxidizing agent. The dry and wet shrinkage, irregularity(CV%), thin and thick part, hairiness and abrasion resistance of these various specimens were measured and discussed in terms of various drawing conditions.

Characterizion of Total Deposition by the Filtered Collection Method (여과식 채취방법을 통한 대기 총침착물의 특성)

  • 김병용;박정호;정재우;박기형;최금찬
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 2002.04a
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    • pp.243-244
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    • 2002
  • 대기 중으로 방출된 대기오염물질의 제거과정에는 주로 강수에 의한 습성침착(wet deposition)과 직접 지표면부근으로 침착하는 건성침착(dry deposition)으로 구분 할 수 있다. 습성침착의 경우 지구 환경문제의 하나로서 주목되고 있는 산성비 문제로 지금까지 국내외의 많은 보고들이 있다. 그러나 건성침착의 경우 침착현상의 복잡성 때문에 건성 침착을 평가하는 표준적인 방법은 아직 정리되어 있지 않은 실정이다. 그러나 건성침착량은 습성침착량과 거의 동등하다고 알려져 있어, 침착 대기오염물질로 인한 지표면 부근의 환경에 주는 부하량을 평가하기 위해서는 습성침착 뿐만 아니라 건성침착을 포함한 총침착물(total=wet+dry) 특성에 대한 연구가 중요하다. (중략)

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Feed Water Flow Control of Super Critical Once Through Boiler in Korea Standard Power Plant (한국표준형 초 임계압 관류형 보일러의 급수제어)

  • 김은기;장용창;조수현
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.251-251
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    • 2000
  • Tangjin Power Plant is modern Korean standard plant which is made up Once Through Super Critical Boiler, Turbin, Generator and Flue Gas Desulfarization System. INFI-90 system fur control of the 500 MW Korean standard super critical once through boiler Mark-V for Turbine, EX-2000 fer Generator, WDPF for FGD were installed in Tangiin thermal power plant. There were two BFPTs, BFPM, 25% control valve, 35% control valve to control boiler feed water flow. It is very difficult to tune the Separator Tank level control system and change the mode from Wet to Dry. This paper focuses on test results and modification control logic for feed water control system in Tangjin power plant.

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WATER INDUCED MECHANICAL EFFECT ON THE DENTAL HARD TISSUE BY THE SHORT PULSED LASER

  • Kwon,Yong-Hoon;Kim, You-Young
    • Journal of Photoscience
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    • v.5 no.1
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    • pp.33-37
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    • 1998
  • One macroscopic effect in the free-running Er:YAG laser is an accumulation of microscopic effects. Understanding of the exogenous water induced mechanical effect on the dental hard tissue by the Qswitched Er:YAG laser has an important impact on the further understanding of the free-running Er:YAG laser ablation on the dental hard tissue. The Q-switched Er:YAG laser (1-$\mu$s-long pulse width) was used in the recoil pressure measurement with an aid of water-jet system and a pressure transducer. The amplitude of the recoil pressure depends on the tooth surface conditions (dry and wet) and the volume of the water upon it. Wet surfaces yielded higher recoil pressure than that of dry, surface, and as the volume of the exogenous water drop increased, the amplitude of the recoil pressure increased also.

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Experimental Study for the Identification of the Nascent Product of OH Heterogeneous Reaction with NaCl using Chemical Ionization Mass Spectrometry

  • Park, Jong-Ho;Ivanov, Andrey V.;Molina, Mario J.
    • Mass Spectrometry Letters
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    • v.3 no.4
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    • pp.108-111
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    • 2012
  • An experimental study on the nascent product of the OH heterogeneous reaction with NaCl was performed under dry and wet conditions using a bead-filled flow tube system coupled to a high-pressure chemical ionization mass spectrometer. The ozone concentration in the flow tube for the atomic hydrogen removal was varied in order to control the conversion reaction of molecular chlorine into HCl for the identification of the nascent product. The mass spectrometric observation was that the $O_3$ introduction reduced the concentration HCl, while it increased the concentration of $Cl_2$ and ClO. Based on the experimental results, we suggest that the nascent product of the titled reaction is gaseous $Cl_2$, which is followed by fast conversion into HCl in presence of H. No significant difference in the concentration profile between under dry and wet (RH = 2%) conditions was observed.

Dynamic Friction of Polyester Air-jet Textured Yarns

  • Rengasamy Raju Seenivasan;Guruprasad Raghavendran;Asis Patnaik
    • Fibers and Polymers
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    • v.6 no.2
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    • pp.146-150
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    • 2005
  • In this paper, friction of air-jet textured yams is investigated. Using a friction measuring apparatus fabricated inhouse, dynamic friction forces of the yams under yarn-to-metal (YM) and yam-to-yam (YY) rubbing modes are measured. The influence of processing variables of air-jet texturing viz., overfeed, air pressure, dry/wet texturing and normal/core-and-effect texturing on dynamic friction is analysed. The results indicate that friction force increases with increasing rubbing speeds and yam input tension. YM dynamic friction decreases initially and then starts to increase at higher overfeeds. YY dynamic friction increases with increasing overfeed. YM dynamic friction decreases with an increase in air pressure while an opposite trend is observed for YY friction. Wet textured yams have higher friction than dry textured yams. Core wetted coreand-effect textured yams have higher friction than normal textured yams.

The Frost and Defrost Performances of Fin-and-Tube Heat Exchangers with Different Surface Treatment Characteristics (서로 다른 표면특성을 갖는 핀-관 열교환기의 착상과 제상 성능평가)

  • 최봉준;황준현;신종민
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.14 no.10
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    • pp.781-785
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    • 2002
  • The effects of different surfaces on dry and wet frosting test were experimentally investigated. The results of experiment were compared by the performance evaluation coefficient (PEC). Results showed that the air-side pressure drop of lacquer coated evaporator increased by 5% as compared to the plasma treated one. It was also found that the Plasma coated evaporator is lower than lacquer coated one in the PEC ratio.

Evaluation on the Electrical Properties of Outdoor Epoxy Resin Insulators under Accelerated Agings (가속열화에 따른 옥외용 epoxy 수지 애자의 전기적특성 평가)

  • Cho, H.G.;Kim, I.S.;Ahn, M.S.
    • Proceedings of the KIEE Conference
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    • 1994.07b
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    • pp.1360-1363
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    • 1994
  • Epoxy resin insulator have good electrical properties (high electric strength, high resistivity, low dielectric loss) in addition to high mechanical strength, small dimensions and design versatility. Polymer insulator, however, are subjected to aging processes, caused by the surrounding atmosphere, which may lead to degradation of their properties. This paper describes the results of a important study on the artificial pollution test, Weather-Ometer properties and rotating wheel dip test of high voltage different aging insulators which are the most important factors for outdoor uses. Also, the objects of this paper are to (a)result of insulator under dry(wet) flashover voltage, (b)artificial pollution test of salt spay, (c)Accelerated aging test of Weather-Ometer, (d) wet and dry flashover voltage under rotating wheel dip test.

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Evaluation of Corrosion Protective System for Reinforced Concrete Structures Constructed With Sea Sand (해사 혼입된 콘크리트 구조물의 부식도 평가)

  • 김웅희;홍기섭;오승모;장지원;최응규;최완철
    • Proceedings of the Korea Concrete Institute Conference
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    • 1997.04a
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    • pp.203-209
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    • 1997
  • An experimental study to evaluate to evaluate corrosion protection systems was undertaken with 44 reinforced concrete slab specimens subjected to cyclic wet and dry saltwater exposure. Corrosion measurements included monitoring macrocell corrosion currents, which are genrerally accecpted in United States practice. Test results indicate that specimens containing 2 kg/$\textrm{m}^3$ of NaCl and exposed to wet(outdoor) and dry(indoor) conditions but not to saltwater show very low values of corrosion measurements regardless applying any corrosion protective systems. Corrosion currents of the specimens exposed at 10 percent of NaCl were higher than that of the specimen exposed at 5 percent of NaCl, so the density of the salt water had an influential effect on the test. For the specimens with water repellent membrane currents kept relatively low numerical values, but test specimens with surface corrosion inhibitor protective system showed high values of corrosion current. It would be expected that evaluation of the corrosion protective systems need long-term measurement.

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