• Title/Summary/Keyword: Dry condition

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Variation of Thermal and Mechanical Properties of Crystalline Granite under Saturated-Loading Condition (침수-하중 조건에서의 결정질 화강암의 열적, 역학적 물성 변화)

  • Heo, Jin;Lee, Jae Chul;Seo, Jung Bum;Park, Seung Hun;Park, Jung Chan;Kwon, Sangki
    • Tunnel and Underground Space
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    • v.24 no.3
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    • pp.224-233
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    • 2014
  • It is well known that rock properties can be affected by loading in underground condition. In the case of flooded underground mine or tunnels, rock properties variation due to loading might be different from the loading in dry condition. In order to verify the influence of saturated loading condition on rock properties, various laboratory tests had been carried out. Loading on the rock specimen was controlled to be ranged in between 20 ~ 80% of UCS. By comparing the variation of thermal, mechanical, and physical properties of rock specimens under the same load in saturated and dry condition, it was possible to find that the rock properties can be more significantly disturbed in the saturated loading condition than in dry loading condition.

Analysis on the Dielectric Characteristics of Dry Air According to Pressures for Developing an Eco-friendly High Voltage Switchgear (친환경 고압배전반 개발을 위한 dry air의 압력별 절연내력특성 분석에 관한 연구)

  • Nam, Seok-Ho;Kang, Hyoung-Ku
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.8
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    • pp.1560-1565
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    • 2011
  • The environmental pollution caused by green-house gases such as $CO_2$ and $SF_6$ has been becoming the main issue of industrial society. Many developed countries are making efforts to minimize the amount of $CO_2$ emission come from the operation of high voltage electrical apparatuses. As a part of these efforts, 180 countries signed the Kyoto Protocol in 1997 to cut back on their green-house gas emissions. Nowadays, the study on the development of dry air insulated switchgear (DAIS) which is known as an eco-friendly electrical apparatus is in progress. A DAIS is advantageous for minimizing the effect of impurities and enhancing the dielectric characteristics over an air insulated switchgear (AIS) by applying constant pressure to an enclosed cubicle. Therefore, a study on the electrical insulation performance of dry air as a gaseous insulation medium is conducted in this paper to substitute a gas insulated switchgear (GIS) for DAIS. As results, it is verified that the AC dielectric characteristics of dry air are similar to those of air and the lightning impulse dielectric characteristics of dry air are superior to those of air at 1bar pressure condition. However, dry air is of inferior dielectric characteristics to $SF_6$ at 4bar pressure condition. Finally, it is suggested that the internal pressure of DAIS should be over 4bar pressure to develop a high voltage switchgear which has similar electrical performance to a conventional GIS. Also, the empirical formulae on calculating the maximum electric field intensity at sparkover of dry air are deduced by experiments according to pressures. It is expected that these results are helpful to design and develop a high voltage electrical apparatus.

BCK-ALGEBRAS WITH SUPREMUM

  • Jun, Young-Bae;Lee, Kyoung-Ja;Park, Chul-Hwan
    • The Pure and Applied Mathematics
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    • v.16 no.1
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    • pp.1-11
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    • 2009
  • The notion of a BCK-algebra with supremum (briefly, sBCK-algebra) is introduced, and several examples are given. Related properties are investigated. We show that every sBCK-algebra with an additional condition has the condition (S). The notion of a dry ideal of an sBCK-algebra is introduced. Conditions for an sBCK-algerba to be an spBCK-algebra are provided. We show that every sBCK-algebra satisfying additional condition is a semi-Brouwerian algebra.

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A Study on the Printability of Printing Paper according to the Changing of Calendering Condition (Calendering 조건 변화에 따른 인쇄용지의 인쇄적성에 관한 연구)

  • Kwon, Young-Jong;Youn, Jong-Tae;Ha, Young-Baeck
    • Journal of the Korean Graphic Arts Communication Society
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    • v.23 no.2
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    • pp.25-43
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    • 2005
  • Generally, machine calendering are used change of paper surface properties. During machine calendering, dry paper passes between the rolls under pressure, thereby improving the surface smoothness and gloss. These improvements make the paper better suited for printing and decreasing problems during the printing, such as delayed dry and set-off. Then we investigated newspaper properties by the changing of machine calendering condition, and relationship printability. Properties of each samples were examined in accordance with KS and TAPPI standard test method i.e, basic weight, bulk density, thickness, porosity, opacity, brightness, smoothness and roughness. IGT printability tester was used to obtain ink requirement of newspaper, printed density and set-off. Results of in this study, we have proposed the optimizes range of newspaper calendering condition. Useful optimize calendering condition was pressure 55 kN/m, temperature $130^{\circ}C$.

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Improvement of Wet-end Performance and Paper Strength with Polyvinylamine

  • Son, Dong-Jin;Kim, Bong-Yong
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.37 no.5 s.113
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    • pp.63-69
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    • 2005
  • This study was performed to introduce recently developed polyvinylamine as a wet-end process and paper strength improving aids. As a retention and drainage aids, high cationic charged polyvinylamine was more effective at the BCTMP and ONP stock condition than LBKP stock condition. As a dry tensile strength aid, dual system of polyvinylamine with anionic polyacrylamide was the best at the LBKP or ONP stock conditions. On the other hand, polyvinyl amine alone was better than dual system of polyvinylamine with anionic polyacrylamide at the BCTMP condition. As a wet tensile strength aid, polyvinylamine single system and dual system of polyvinylamine with anionic polyacrylamide were good at LBKP, BCTMP and ONP stock conditions. However, poly(aminoamide)-epichlorohydrin resin was good at LBKP and ONP stock conditions but efficiency of poly(aminoamide)-epichlorohydrin resin was remarkably decreased at BCTMP stock condition.

Effect of Temperature Condition on Growth of Juvenile Abalone, Haliotis discus hannai with the Different Feeds (사료 종류별 사육수온이 전복 치패의 성장에 미치는 영향)

  • Cho, Sung-Hwoan;Cho, Young-Jin
    • The Korean Journal of Malacology
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    • v.25 no.2
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    • pp.121-126
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    • 2009
  • This study was performed to determine the effect of temperature condition on growth of juvenile abalone Haliotis discus hannai with the different feeds. Two types of feed (dry sea tangle and experimental diet) at water temperatures of 20 and $23^{\circ}C$, and 23 and $26^{\circ}C$ were applied to experimental abalone twice. Forty-five juvenile abalone averaging 10.1 g in the first feeding trial and 11.5 g in the second feeding trial were randomly stocked into 6 of 50 L plastic rectangular containers each. Fishmeal, soybean meal and shrimp head meal was used as the primary protein source in the experimental diet. And dextrin and wheat flour, and soybean oil were used as the primary carbohydrate and lipid sources in the experimental diet, respectively. The dry sea tangle and experimental diet were fed to abalone once a day at the ratio of 1.5-2.0% total biomass of abalone with a little leftover in each experimental condition. Weight gain of abalone was significantly affected by feed type, but not by water temperature in the first feeding trial. Regardless of water temperature, weight gain of abalone fed the experimental diet was significantly higher than that of abalone fed the dry sea tangle. However, weight gain of abalone was significantly affected by water temperature, but not by feed type in the second feeding trial. Weight gain was highest in abalone fed the experimental diet at $23^{\circ}C$, followed by abalone fed the dry sea tangle at $23^{\circ}C$, abalone fed the experimental diet and dry sea tangle at $26^{\circ}C$, which was lowest. Moisture and crude protein content of the edible portion of abalone was significantly affected by feed type, but not by water temperature in the second feeding trial. However, ash content of the edible portion of abalone was significantly affected by water temperature, but not by feed type. In considering these results, it can be concluded that the well formulated feed was superior to the dry sea tangle for growth of juvenile abalone, and water temperature conditions of 20 and $23^{\circ}C$ seemed to be better than $26^{\circ}C$ to improve weight gain of abalone.

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Effects of IAA Seed Pretreatment on Reduction of CNP and Butachlor Injury to Rice (IAA의 종자침지처리(種子浸漬處理)가 CNP와 Butachlor에 의한 수도약해(水稻藥害)의 경감(輕減)에 미치는 영향)

  • Pyon, J.Y.;Kwon, Y.W.;Lee, E.W.
    • Korean Journal of Weed Science
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    • v.2 no.2
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    • pp.141-145
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    • 1982
  • In order to determine the possibility of reducing rice injury caused by CNP and butachlor application, the effects of IAA seed presoaking on CNP and butachlor action against early growth of rice seedlings were investigated under flooded direct-seeding and dry-seeded conditions. CNP and butachlor injury to rice was reduced by soaking rice seeds at 0.1, 1.0 and 10ppm of IAA solution for 36 hours before seeding under flooded condition and thus shoot length and dry weight of rice seedlings increased compared with those of IAA untreated seedlings. IAA seed pretreatment also overcame the inhibitory effect of CNP and butachlor under dry-seeded condition. Effect on reducing rice injury by IAA pretreatment was more remarkable when CNP applied under dry seeded condition and butachlor under flooded condition.

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Effect of Cooking Condition on the Water-Soluble Flavor Precursors in Various Beef Muscles from Hanwoo (Korean Cattle)

  • Kang, Sun Moon;Kang, Geunho;Seong, Pilnam;Kim, Youngchun;Park, Beomyoung;Cho, Soohyun
    • Food Science of Animal Resources
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    • v.33 no.6
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    • pp.752-756
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    • 2013
  • This study was carried out to investigate the effect of cooking condition on the water-soluble flavor precursors relevant to postmortem glycogen metabolisms in various beef muscles from Hanwoo (Korean cattle). The loins, striploins, top rounds, and eye of rounds from 40-mon-old heifers were cooked in either with $100^{\circ}C$ water bath (wet-cooking) or $180^{\circ}C$ household electric oven (dry-cooking) until attained to about $80^{\circ}C$ of internal temperature before the measurements of amounts of macroglycogen, proglycogen, free glucose, and lactate. The macroglycogen and proglycogen contents were not significant differences in all beef muscles between the wet-cooking and dry-cooking treatments. Regardless of cooking condition, the both loin and top round had higher (p<0.05) two types of glycogen than the eye of round. The free glucose and lactate contents presented higher trends in the dry-cooking treatment compared with the wet-cooking treatment. The wet-cooked top round had higher (p<0.05) free glucose than the wet-cooked eye of round. Moreover, the top round contained the highest lactate content regardless of cooking condition. Consequently, it is considered that the dry-cooking treatment would be more beneficial to the flavor of cooked beef muscles than the wet-cooking treatment.

Changes in Sugars Composition of Dried Lavers during Storage (마른김의 당류조성(糖類組成)과 저장중의 변화)

  • Park, Young-Ho
    • Korean Journal of Food Science and Technology
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    • v.5 no.4
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    • pp.235-239
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    • 1973
  • Studies were made on the sugars composition in dried lavers (Porphyra yezoensis Ueda) and changes in the contents of sugars during the storage under a dry and a humid conditions respectively. 1) No notable difference was observed in the glucose content between those dried lavers samples, which were stored under dry and humid conditions. Galactose content showed little change under a dry condition, but under a humid condition rapidly increased to a maximum of about ten times of its initial amount and then decreased gradually. 2) The content of floridoside rapidly decreased under a humid condition while slowly decreased under a dry condition, of which tendency is a contrast to that of galactose. 3) One of the unidentified components, which is deduced to be isofloridoside, showed a fluctuation pattern, which bears resemblance to that of floridoside.

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Estimation of Vehicle Speed using Skid Mark (스키드 마크를 이용한 자동차 속도 추정)

  • Hong, Yu-Sik;Han, Chang-Pyeong
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 2005.11a
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    • pp.471-474
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    • 2005
  • For the purpose of objective and scientific inspection, traffic accidents should be appraised and inspected by righteous material evidences, computer simulation, and studies such as automobile engineering, traveling and collision accident dynamics, road and traffic engineering. In this paper, it displays the results of studying cases with the reasons of traffic accidents by analyzing and studying automobile kinetics, real traffic accidents and the results of in scientific and objective ways. In this paper, it is proved that with compared by dry and wet road surface condition, the transient brake time of wet condition is longer than dry road condition. Moreover, compared with unpacked road condition and packed road condition. unpacked road condition is shorter than packed road condition using computer simulation.

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