• Title/Summary/Keyword: deaeration

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The Study on the Corrosion Behavior of Al-alloy Radiator for Automobile in Fresh Water (청수 중에서 자동차용 Al합금 방열기의 부식거동에 관한 연구)

  • 임우조;이상열;윤대영
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.38 no.4
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    • pp.265-270
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    • 2002
  • Most of all the mechanical devices are becoming more high-speed and high-power as well as their used condition being more pollution with rapid development in industrial part. So, it is necessary for these devices to equip cooling system to overcome that kind of severe using condition. Industrial development and income increase causes rapid increase in using fossilenergy and it results in accelerating environmental pollution owing to the increasement in emission of air pollution substance. Specially, fresh water like stream and river water is acidified. Therefore, corrosion damage is accelerated in radiator for automobile that is using acidified water. So, in this study, corrosion test was carried out in distilled and tap water for the investigation on the corrosion behavior of Al-alloy that is using as material for radiator of automobile The main results obtained are as follows According to increase of temperature, open circuit potential is decreased in fresh water. And open circuit potential after deaeration is lower than that before deaeration. Corrosion current density in distilled water is less drained than that of tap water. And Corrosion current density after deaeration is less drained than that before deaeration.

Alteration of Physical and chemical Characteristics of Waterlogged Archaeological Woods After Cleaning (세척 후 수침고목재의 물리.화학적 특성 변화)

  • Cha, Mi-Young;Lee, Kwang-Ho;Kim, Yoon-Soo
    • Journal of Conservation Science
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    • v.19
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    • pp.19-30
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    • 2006
  • Alteration of physical and chemical characteristics and the effect of removal of mineral substances in waterlogged archaeological woods by different cleaning processes were examined using oak wood(Quercus spp.) that was excavated from wetland near Gwangju, Korea. Cleaning methods employed in the present work were (1) tools, (2) deaeration, (3) EDTA and (4) ultrasonic cleaning, which are being currently applied in the field of preservation treatment. Cleaning process were performed independently or continuously. Composition of mineral substances in the waterlogged archaeological wood was almost same as the that of soil in which waterlogged archaeological woods were buried. In case of independent cleaning, tools cleaning efficiently removed the mineral substances on surface. Surface color become brighter after cleaning with EDTA. In contrast, deaeration and ultrasonic cleaning did not show any significant removal of mineral substances. In continuous cleaning process, tool cleaning as the first step treatment showed the same effect as shown in independent cleaning. Although deaeration as the second step cleaning did not remove the mineral substances, it could be assumed to contribute the infiltration of dimensional agents by homogenization of wood. EDTA treatment (the third step cleaning) removed the iron(Fe) and increased the whiteness of wood color. The ultrasonic treatment (the fourth step cleaning) removed the sodium(Na) remained after EDTA treatment and the fine mineral substances.

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The Analysis of Environmental Impact Load by Fibrous Raw Materials and Wet-end Additives in Papermaking Process (제지공정 섬유상 원재료 및 공정 첨가제의 환경오염 부하 분석)

  • Kim, Hyoung-Jin;Shin, Dong-Uk
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.37 no.3
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    • pp.50-58
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    • 2005
  • It is generally known that paper industry is the second largest industry in the use of process water, and also have the highest environmental impact load in the contaminant sources. Paper is produced from the mixtures composed of 1% fibrous raw materials and 99% water. The optimum use of process water effects on the quality properties of paper and the environmental impact load of waste water treatment. In this research, the kinds of fibrous raw material & additives used in the paperboard production line were investigated, and the quantification of environmental loads and the environmental effects of process water on COD potential were evaluated. The NBDCODs were also analyzed from process water by the method of waste water treatment in paper mill and applied for the optimum use of recycling water, and zero effluent process. In the fibrous raw materials, KOCC caused the highest COD potentials, and sack paper & UKP was comparatively low. The NBDCOD of KOCC largely reduced after biological treatment because of easily biodegradable properties, but AOCC contained non-biodegradable materials. In chemical additives, COD was high in turns of rosin>starch>deaeration agent>dye, NBDCOD greatly reduced in starch and deaeration agent. In the case of 2 kinds of paperboard product, the COD potentials was mainly high in starch, AOCC and KOCC.

A Study on Corrosion Characteristics of $SUP-9/50CrV_{4}$by Surface Processing (표면처리법에 따른 $SUP-9/50CrV_{4}$의 부식특성에 관한 연구)

  • Jung, Jae-Wook;Park, Kyung-Dong
    • Proceedings of the KSME Conference
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    • 2004.11a
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    • pp.319-324
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    • 2004
  • In this study, the high strength and superior toughness spring steels as the suspension material, used for automobile and railroad industries were utilized to carry out the following investigations. Corrosion times were controlled in 7, 14, 30 and 60days to examine the relation between corrosion pit and compressive residual stress in the static corrosion environment after shot peened. And then corrosion current and corrosion potential were measured for every 24 hours to investigate the corrosion mechanism. Shot peened material shows the low or rate of corrosion current as compared with unpeened material. In case of peened material which has the highest residual stress, it has a low corrosion current density.

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Effects of Water Circulation on the Phosphorus Release Rate from Sediments in the Lake (호수의 물 순환이 저니의 인 용출율에 미치는 영향)

  • Kim, Geonha;Jeong, Woohyeok;Choi, Seunghee
    • Journal of Korean Society on Water Environment
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    • v.21 no.6
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    • pp.595-601
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    • 2005
  • In this research, effects of water circulation on phosphorus release from sediment into water body were studied. Sediments sampled at the Daechung Lake were used for the column experiments with circulation and non-circulation conditions. Deaeration coefficient, $K_1$ and reaeration coefficient, $K_2$ of non-circulation condition were 0.133 and 0, respectively, while $K_1$ and $K_2$ for circulation condition were 0.46 and 0.018, respectively. Oxidation Reduction Potential (ORP) showed a linear relationship with dissolved oxygen (DO) when DO is over 2 mg/L. Phosphorus concentration induced by phosphorus release from sediment was highly dependent upon DO, ORP, and pH. Under anaerobic condition, phosphorus release rate was higher for $Fe^{2+}$-bounded phosphorus compared to that of $Ca^{2+}$-bounded phosphorus.

Determination of Ethylene Oxide Rexidue and its Secondary Products in Powdered Food (분말상 식품에 있어서 Enthylene Oxide의 잔류성과 이차생성물 분석)

  • 권중호;김석원;변명우;조한옥;이기동
    • Journal of Food Hygiene and Safety
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    • v.9 no.1
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    • pp.43-48
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    • 1994
  • Instrumental determination was performed for the analysis of residues of ethylene oxide(EO), ethylene chlorohydrin(ECH) and ethylene glycol(EG) in white ginseng powders which were deaerated for 30 min after EO fumigation. Gas chromatographic data showed that EO residues were 570 ppm in the immediate samples after deaeration and 170 ppm in the stored ones for 8 days at 30$\pm$1$^{\circ}C$, respectively, showing a decreasing tendency with elapsed time. On the other hand, ECH and EG residues in samples as the secondary products of EO were 17, 650 ppm and 727 ppm stored for one month, and 9, 595 ppm and 221 ppm stored for 3 months, respectively.

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A Study on the Mechanism of Oil Aeration in Automotive Engines(I) (엔진 오일의 공기 혼입 발생기구에 관한 연구(I))

  • 이두순;김원규;오대윤;최재권
    • Transactions of the Korean Society of Automotive Engineers
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    • v.7 no.7
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    • pp.129-135
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    • 1999
  • We developed a new measuring equipment which makes it possible to perform on-line measurements with the merits of its implicity and the time-saving characteristics. By using the newly developed measurement system, the amount of aeration is directly measured on several parameters, i.e, engine speed, oil quantity, oil deterioration, oil temperature and viscosity, etc. It showed that oil aeration is strongly related to be gas movements in crankcase and the residence time of circulating oil in oil pan. In addition, in order to clarify the mechanism of aeration and to quantify the degree of aeration, a modelling analysis to predict aeration was performed , and as a guiding parameter, Aeration Index was defined. Finally, the parameter was compared with the actual amount of aeration, and it was confirmed that they gave a good correlation with each other.

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Effects of Packing Materials on the Keeping Freshness of Chinese Chives(Allium Tubersum Rottler) at Low Temperature Storage (부추 저온저장시 선도유지에 미치는 포장재료의 효과)

  • Kim, Chang-Bae;Lee, Suk-Hee;Kim, Jong-Su;Yoon, Jae-Tak;Kim, Tak
    • Food Science and Preservation
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    • v.6 no.3
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    • pp.270-275
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    • 1999
  • During the storage period of chives(Allium Tubersum fouler) at low temperature(4-5$^{\circ}C$), weight loss in chives by the packages of LDPE, p.p and HDPE film was decreased less than 1%, however that of chives unpacked was remarkably increased as time went by. Soluble solids of unpacked chives was decreased from 6.0 to 4.6 $^{\circ}$Brix after 2 weeks storage and that of LDPE film sealed was lessened to 4.9-5.9 $^{\circ}$Brix, the treatment of deaeration showed a tendency to decrease a lot to 4.5-4.7 $^{\circ}$Brix. The vitamin C content of chives unpacked was 37.1mg% at before storage, but after one week decreased very much to 15.2mg%, and that in chives packed by the different methods was visibly lessened after 2 weeks storage. the Vitamin C content in chives processed by deaeration sealing method was lessened compared to that at chives processed by sealing only. In the bag of chives packed by HDPE film had low CO$_2$ and C$_2$H$_4$ concentration and the gas concentration in the bag of chives processed by P.P. film was increased as storage period went by. Conclusively the freshness of chives packaged by LDPE and HDPE film maintained for 3 weeks, at P.P film for 2 weeks, but the marketability of chives unpacked was degraded in 3-4 days.

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Impact of Thickness of Sand Capping on Phosphorus Release Rate from Sediment (모래 캡핑 두께가 퇴적물 인 용출에 미치는 영향)

  • Jeong, Woo-Hyeok;Kim, Geon-Ha
    • Korean Journal of Ecology and Environment
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    • v.39 no.3 s.117
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    • pp.331-339
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    • 2006
  • This research was carried out to understand the impacts of thickness of sand capping to control phosphorus release from sediment into overlying water. As capping effectively retards release flux, phosphorus concentration in water body can be maintained if phosphorus release rate was kept under microbial degradation rate. With capping thickness increases, deaeration rate become less, while reaeration coefficient become higher. Phosphorus release rate and capping thickness were linearly correlated. The results of regression analysis indicated that phosphorus release can be controlled effectively by sand capping of least 20${\sim}$40 mm thickness.