• Title/Summary/Keyword: pressure effects

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Effects of the Process Variables of Condebelt Drying on Linerboard Properties Made from KOCC (콘디밸트 건조공정 변수가 국산 골판고지로 제조한 라이너지의 물성에 미치는 영향)

  • 이학래;윤혜정;정태민;김진두
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.31 no.3
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    • pp.19-25
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    • 1999
  • Effects of the process variable in Condebelt press drying including drying temperature, pressure , drying time, and moisture content of the sheets on the paper properties were examined. The experiment was performed with a static rig and Korean OCC was used as raw material. Significant improvement in sheet density, compression strength, tensile strength, surface smoothness ,etc. was obtained when condebelt drying was applied. Control of pressure and inlet dryness was found to be two most critical variables in improving sheet properties.

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A Study on the Engine Lubrication System Analysis Adapting Discontinuous Oil Supply Crankshaft System (불연속 오일공급 크랭크샤프트 시스템을 채택한 엔진 윤활시스템의 해석)

  • 윤정의
    • Tribology and Lubricants
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    • v.20 no.1
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    • pp.27-32
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    • 2004
  • This paper presents unsteady oil flow behaviors in the engine lubrication network to clarify the differences between continuous and discontinuous oil supply crankshaft system. Using commercial network analysis program, Flowmaster2, engine lubrication network system analysis were carried out. And effects of crankshaft speed and supplied oil pressure on pressure fluctuation in oil groove and oil flow rate to each bearing were analyzed.

Interference Effects of Neighboring Structures on Wind Pressure (인접 구조물의 상호 간섭 효과 해석)

  • Park, Sang-Jun;Lee, Seung-Un;Lee, Seung-Su
    • Proceeding of EDISON Challenge
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    • 2014.03a
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    • pp.574-578
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    • 2014
  • 본 연구에서는 인접 구조물의 상호 간섭에 의한 풍압 변화에 대한 분석을 수행하였다. 두 개의 구조물 사이의 거리 및 위치를 변경하여 비교 해석하는 것으로써 사각형 구조물 구현을 위해 EDISON_CFD를 이용하여 수치해석을 하였고, 유한 체적 법(Finite Volume Method, FVM) 기반의 범용 비압축성 유동 해석을 위해 2D_Incomp-P_2.1 해석자를 사용하였다. 이 연구를 통하여 인접한 구조물의 영향을 분석하여 상호 간 거리와 위치를 결정할 수 있는 근거자료를 확보하였다.

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A Numerical Model of Thermoacoustic Refrigerators (열음향냉동기의 수치적 모델)

  • 채왕병;정은수
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.8 no.1
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    • pp.110-119
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    • 1996
  • A numerical of thermoacoustic refrigerators has been developed. Effects of heat transfer and viscosity on pressure and velocity distributions in resonators and heat exchangers were considered. Predictions of cooling capacity and COP agreed well with previous experimental results. Effects of important design parameters, such as pressure ratio, spacing between the plates in the stack and stack length, on the performance of thermoacoustic refrigerators were shown.

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Pharmacological Studies on Root Bark Extract of Aralia elata -General Pharmac \logical Action on the Butanol Fraction- (두릅나무 근피 추출물의 약물학적 연구 - 두릅나무 추출물의 Butanol분획의 일반약리작용 -)

  • 정춘식;이은방
    • YAKHAK HOEJI
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    • v.37 no.6
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    • pp.631-637
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    • 1993
  • In the previous report, it was described that the butanol fraction of the root bark extract of Aralia elata had potent antigastritic and antiulcerative effects in rats, In this pharmacological profile, the fraction revealed low acute toxicities in mice and rats, no central nervous system activities, moderate analgesic action, weak inhibitory action in carrageenin edema of rats and no direct effects on isolated smooth muscles of rats and guinea-pigs. Slight lowering of blood pressure as given i.v. in rabbit was observed.

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Treatment of Snoring and Obstructive Apnea with Oral Appliance (코골이와 수면무호흡증의 구강내 장치 치료)

  • Tae, Il Ho
    • The Journal of the Korean dental association
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    • v.53 no.4
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    • pp.259-265
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    • 2015
  • Recently, oral appliances for treating snoring and obstructive sleep apnea are widely used. Among various appliances, mandibular advancement devices are most effective without serious side effects. Advancement of mandible keep airway open and decrease snoring and/or obstructive apnea events. They can be used as stand-alone therapy or an adjunct to continuous positive air pressure for lowering air pressure. Oral appliances should be applied by dentists who have knowledges and experiences on occlusion and temporomandibular disorders and manage of side effects.

Synthesis and Biological Activities of New Substituted Indoles

  • Hishmat, Orchidee H.;Nakkady, Sally S.;El Shabrawy, Osama A.;Mahmoud, Sawsan S.
    • Archives of Pharmacal Research
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    • v.15 no.1
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    • pp.104-108
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    • 1992
  • 2, 3-Diphenyl-6-formyl-5-methoxyindole reacts with ethyl cyano acetate to yield the arylidene derivative which forms with urea and thiourea the corresponding pyrimidine derivatives. The arylidene derivatives react with hydrazines and with active methylenes to form the respective pyrazole derivatives and the $\alpha, \;\beta$-disubstituted acrylonitriles. Seven new compounds were tested for their effects on the arterial blood pressure of rats and analgesic activity.

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Influence of Injection Rate Shaping on Combustion and Emissions for a Medium Duty Diesel Engine

  • Benajes, J.;Molina, S.;Rudder, K. De;Rente, T.
    • Journal of Mechanical Science and Technology
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    • v.20 no.9
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    • pp.1436-1448
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    • 2006
  • This paper describes the effects of injection rate shaping on the combustion, fuel consumption and emission of $NO_x$ and soot of a medium duty diesel engine. The focus is on the influence of four different injection rate shapes, square type 1, square type 2, boot and ramp, with a variation of maximum injection pressure and start of injection (SOI). The experiments were carried out on a 1 liter single cylinder research diesel engine equipped with an amplifier-piston common rail injection system, allowing the adjustment of the injection pressure during the injection event and thus injection rate as desired. Two strategies to maintain the injected fuel mass constant were followed. One where rate shaping is applied at constant injection duration with different peak injection pressure and one strategy where rate shaping is applied at a constant peak injection pressure, but with variable injection duration. Injection rate shaping was found to have a large effect on the premixed and diffusion combustion, a significant influence on $NO_x$ emissions and depending on the followed strategy, moderate or no influence on soot emission. Only small effects on indicated fuel consumption were found.

Waterproofing Mechanism of Hardened Cement Paste with Waterproofing Materials (구체방수제가 혼입된 시멘트 경화체의 방수 메카니즘)

  • Kang, Hyun Ju;Song, Myong Shin;Park, Jong Hun;Jeon, Se Hoon;Lee, Sung Hyun
    • Journal of the Korean Ceramic Society
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    • v.50 no.1
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    • pp.25-30
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    • 2013
  • The pore volume of hardened cement with waterproofing materials is lower compared to that of hardened cement without waterproofing materials. Thus, fewer gaps will appear by means of chemical reactions between $Ca^{2+}$ ions in hardened cement and water, solutes, and other ions. Due to the selective permeability, the osmotic pressure of hardened cement can change due to physical effects such as the reduction of the pore volume and the reduction in the number of pores, as well as by the electrochemical reaction between water, solutes, other ions and $Ca^{2+}$ ions in hardened cement. Of course, these factors do not have independent effects but instead a combined complex effect. Accordingly, we studied changes in the osmotic pressure due to the difference in the pore structure of hardened cement. A pore size smaller than 1 nm in hardened cement had only a slight effect on the osmotic pressure, whereas a pore size larger than 1 nm had a direct effect on the osmotic pressure.

Analysis of Tube Support Plate Reinforcement Effects on Burst Pressure of Steam Generator Tubes with Axial Cracks (증기발생기 전열관지지판의 축균열 파열억제 효과 분석)

  • Kang, Yong Seok;Lee, Kuk Hee;Kim, Hong Deok;Park, Jai Hak
    • Journal of the Korean Society of Safety
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    • v.30 no.4
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    • pp.168-173
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    • 2015
  • A steam generator tubing is one of the main pressure boundary of the reactor coolant system in the nuclear power plants. Structural integrity refers to maintaining adequate margins against failure of the tubing. Burst pressure of a tube at tube support plate can be higher than that for a free-span tube because failure behaviors could be interfered from the tube support plate. Alternative repair criteria for out-diameter stress corrosion cracking indications in tubes to the drilled type tube support plate were developed, however, there are very limited information to the eggcrate type tube support plate. This paper discussed reinforcement effect of steam generator tube burst pressure with axial out-diameter stress corrosion cracking within an eggcrate type tube support plate. A series of tube burst tests were performed under the room temperature and it was found out that there is no significant but marginal effects.