• Title/Summary/Keyword: temperature history

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Temperature background characteristics of concrete according to changes in bubble sheet types in hot weather environments (서중환경에서 버블시트 종류 변화에 따른 콘크리트의 온도이력 특성)

  • Lee, Jea-Hyeon;Lee, Jae-Jin;Lee, Sang-Un;Lee, Joung-Gyo;Han, Min-Cheol;Han, Cheon-Goo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2016.10a
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    • pp.132-133
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    • 2016
  • This research team has developed single silk white bubble sheets to be used as surface sheath curing material for spring, summer, and autumn. But though its effects for spring and autumn temperature conditions have been proved, there haven't been any studies for summer temperature conditions. Therefore in this study, single silk white bubble sheets and single silk transparent bubble sheets as well as aluminum metalizing single silk bubble sheets have been applied to actual box-frame apartment slabs in construction, in order to compare temperature backgrounds of the concrete and other qualities. Upon application, the temperature of concrete cured in summer temperature conditions showed excellent scores, being the lowest for aluminum metalizing single silk white bubble sheets, then single silk transparent bubble sheets. But the aluminum metalizing single silk bubble sheet gave off a harmful glare, so for actual use, white single silk bubble sheets are recommended.

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A Study on Improved Heating Performance of an Apartment Housing Unit (공동주택 세대별 난방 성능 개선 연구)

  • Seo, Jeong-Ah;Shin, Younggy;Kim, Yong-Ki;Lee, Tae-Won
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.28 no.2
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    • pp.69-74
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    • 2016
  • Most hot water heating valves for apartments are constant-flow types, which limit the flow rate through an individual household for even distribution of heating water to other households. The constant-flow type is implemented by an on-off control. As a result, heating water is supplied intermittently and hence, indoor air temperature also fluctuates. Returning water temperature is also high, which reduces energy efficiency. To implement continuous feedback control, the indoor temperature dynamics was simulated to fit a measured temperature history by a state-of-the-art physical model. From the model, it was found that the most important disturbance is outdoor temperature and its effect on indoor temperature lasts about an hour. To cope with the slow response and the significant disturbance, a prediction control with proportional feedback is proposed. The control was found to be successful in implementing continuous heating water flow and improved indoor temperature control.

A Study on In-Cylinder Measurement of Flame Temperature and Soot Distribution in D.I. Diesel Engine Using Tow-Color Method (이색법을 이용한 직접 분사식 디젤엔진 실린더내의 화염 분도 및 Soot 분포 측정에 관한 연구)

  • 박정규;정수훈;원영호
    • Transactions of the Korean Society of Automotive Engineers
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    • v.7 no.7
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    • pp.42-53
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    • 1999
  • Two dimensional flame temperature and KL value distribution from the luminous flame containing soot in a DI diesel engine were measured by the tow-color method using tow different wavelengths of the flame image. The combustion chamber of a DI diesel engine was visualized by elongating the piston and cylinder and the flame in the combustion chamber was photographed on a nega-color film using a high speed camera. In this study, color CCD camera was used to digitize the three color density of the film exposed to the flame and standard lamp . The accuracy of the measuring method depends on the calibration line of film made from a high temperature standard tungsten lamp. The formation and oxidization of soot in the diesel engine were studied by observing measured time history of KL factor and flame temperature . Also , effects of various shapes of combustion chamber and fuel injection on flame temperature. Also, effects of various shapes of combustion chamber and fuel injection on flame temperature and KL value distribution were examined.

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Reproductive Ecology and Early Life History of Paradise Fish, Macropodus chinensis (Pisces; Belontidae) in Aquarium (버들붕어, Macropodus chinensis의 생식생태와 초기생활사)

  • Song, Ho-Bok;Choi, Shin-Sok
    • Korean Journal of Ecology and Environment
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    • v.33 no.3 s.91
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    • pp.282-294
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    • 2000
  • The reproductive ecology and the early life history of Macropodus chinensis were investigated in aquarium. Mature male made the bubble nest and spawned with wrapping the female and reverse posture. The parental male protected the offspring until the larvae depart the bubble nest. Egg productivity and egg hatching rate were the highest at water temperature in $28^{\circ}C$ and $26^{\circ}C$ respectivity than any other artificial temperature. The eggs were buoyant, globular and 0.95${\sim}$1.05 mm in diameter. Cleavage was progressed at intervals of 15 minutes. Eggs hatched in 42${\sim}$44hours after fertilization and the newly hatched larvae were 3.0${\sim}$3.2 mm in total length. The lawae were 4.5${\sim}$5.4 mm in 4${\sim}$5 days after hatching and fed on the food with dispersion from the nest. In 40${\sim}$45 days after hatching, all fin rays completely developed, and juveniles reached 18.2${\sim}$23.5 mm in total length. In 90${\sim}$110 days after hatching, body from of young fishes were similar to adult with 37.4${\sim}$48.2 mm and represented secondary sexual characters longer than 45.0 mm in total length, and about 120 days, fishes began spawning(water temperature for ontogenesis: $26.0{\pm} 1^{\circ}C$).

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Reproductive Phenology of Gracilaria verrucosa (Rhodophyta) in Cheongsapo near Pusan, Korea

  • Kim Young Sik;Choi Han Gil;Kim Hyung Geun;Nam Ki Wan;Sohn Chul Hyun
    • Fisheries and Aquatic Sciences
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    • v.1 no.1
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    • pp.147-151
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    • 1998
  • The reproductive phenology of Gracilaria verrucosa was studied in Cheongsapo near Pusan, Korea. Among the life history phases, tetrasporic plants occurred dominantly in varying degrees of abundance throughout the year except from July to September. Cystocarpic plants increased rapidly during summer, and then recorded maximum abundance in July. Whereas, seasonal peaks of spermatangial plants were observed in April and September. However, they were less than cystocarpic plants in abundance. Vegetative plants dominated from December to May for long period, with a occurrence peak in February. Even though fertile plants in both gametophytes and tetrasporophytes occurred throughout the year, their seasonal abundance suggests that the positive correlation between reproduction and water temperature is basically found in the reproductive pattern of Gracilaria verrucosa. The distributional aspect of life history phases appears to be related with differences of their longevity, fecundity or survivorship.

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Egg Development and Early Life History of Korean Endemic Species Korean Spotted Sleeper, Odontobutis interrupta (Pisces: Odontobutidae)

  • Park, Jae-Min;Han, Kyeong-Ho;Kim, Na-Ri;Yoo, Dong-Jae;Yun, Seong-Min;Han, Ji-Hyeong
    • Development and Reproduction
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    • v.18 no.4
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    • pp.259-266
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    • 2014
  • The egg development and early life history of Korean spotted sleeper, Odontobutis interrupta which is Korean endemic species from Sora-choen was investigated. The Korean spotted sleeper were caught at Sora-myeon, Yeosu-si, Jeollanamdo, from Korea at May in 2014. The fertilized eggs were $4.23{\pm}0.05mm$ in long diameter and had oil globules. Hatching time of the embryo began about 442 hr 14 min after fertilization under water temperature of $19.5^{\circ}C$. The newly hatched larvae were $4.27{\pm}0.35mm$ in total length and their anus were not yet opened. 3 days after hatching postlarvae was measured $6.20{\pm}0.11mm$ in total length. 10 days after hatching postlarvae was measured $6.69{\pm}0.14mm$ in total length.

Development of Eggs and Early Life History of Korean Bitterling, Rhodeus pseudosericeus (Acheilognathinae) (한강납줄개, Rhodeus pseudosericeus (Acheilognathinae)의 난 발생과 초기생활사)

  • Kim, Chi-Hong;Kang, Eon-Jong;Kim, Jong-Hwa
    • Korean Journal of Ichthyology
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    • v.18 no.3
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    • pp.266-272
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    • 2006
  • The egg development and early life history of Korean endemic bitterling Rhodeus pseudosericeus were observed under the controlled water temperature, $17.0{\pm}0.5^{\circ}C$. Fertilized eggs are opaque yellow in color, measuring 2.9~3.1 mm in length and 1.6~1.9 mm in breadth. The eggs of this species began to hatch about seventy hours after insemination and the range of total length of larvae were 3.2~3.4 mm. The larvae reached at the heterotrophic stage about twenty-five days after hatching. R. pseudosericeus had a pair of wing-shaped yolk projection during the prelarval stage that is a common character of the genus Rhodeus.

The Effect of Cold and Elevation on Skin Temperature (냉과 거상이 피부 온도에 미치는 영향)

  • Kim, Min-Kyu;Current, Marion E.;Kim, Hyo;Lee, Jung-Bae
    • Physical Therapy Korea
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    • v.3 no.1
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    • pp.48-56
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    • 1996
  • The research of cold therapy is preceding rarely nowadays. This study was researched to measure the skin temperature of the right foot malleolus when the leg change the situation precisely speaking it was cold, elevation, cold plus elevation. Twenty young healthy volunteers(M:10, F:10)with no history of cardiopulmonary disease, peripheral artery disease were tested. This study were analyzed by one-way-repeated ANOVA. In the first we examined the within changes of the skin temperature between before and after examination for each modality. The skin temperature at all of modalities had fallen. Therefore we could know the fact that elevation plus cold modality had fallen skin temperature significantly more than elevation or cold. And there were no significant difference between male and female. We conclude that elevation and cold therapy could be better effective on edema, contusion and sprain than cold or elevation therapy independently.

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High Temperature Structural Integrity Evaluation Method and Application Studies by ASME-NH for the Next Generation Reactor Design

  • Koo, Gyeong-Hoi;Lee, Jae-Han
    • Journal of Mechanical Science and Technology
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    • v.20 no.12
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    • pp.2061-2078
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    • 2006
  • The main purpose of this paper is to establish the high temperature structural integrity evaluating procedures for the next generation reactors, which are to be operated at over 500$^{\circ}C$ and for 60 years. To do this, comparison studies of the high temperature structural design codes and assessment procedures such as the ASME-NH (USA), RCC-MR (France), DDS (Japan), and R5 (UK) are carried out in view of the accumulated inelastic strain and the creep-fatigue damage evaluations. Also the application procedures of the ASME-NH rules with the actual thermal and structural analysis results are described in detail. To overcome the complexity and the engineering costs arising from a real application of the ASME-NH rules by hand, all the procedures established in this study such as the time-dependent primary stress limits, total accumulated creep ratcheting strain limits, and the creep-fatigue damage limits are computerized and implemented into the SIE ASME-NH program. Using this program, the selected high temperature structures subjected to two cycle types are evaluated and the parametric studies for the effects of the time step size, primary load, number of cycles, normal temperature for the creep damage evaluations and the effects of the load history on the creep ratcheting strain calculations are investigated.

Investigation on the Applicability for Method of Setting Time Difference by Super Retarding Agent for Reducing Hydration Heat of Transfer Girder Mass Concrete (전이보 매스콘크리트의 수화열저감을 위한 초지연제 응결시간차 공법의 적용가능성에 대한 검토)

  • Yoon Seob;Hwang Yin Seong;Baik Byung Hoon;Han Cheon Goo
    • Proceedings of the Korea Concrete Institute Conference
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    • 2004.05a
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    • pp.128-131
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    • 2004
  • This paper is to investigate the mock up test results of mass concrete for transfer girder using setting time difference with super retarding agent(SRA) to reduce hydration heat. According to test results, the temperature history of plain concrete without placing lift had a steep rising curvature, and plain concrete had a big temperature difference between surface and middle section of mass concrete, which may result in occurrence of temperature crack. However, considering placing method B, because setting time of middle section concrete was retarded with an increase in SRA contents, higher hydration heat temperature was observed at surface section concrete compared with that at middle section concrete at early age, which can lower the possibility of hydration heat crack. In case of placing method C, although peak temperature of hydration heat was much lower, at early age, high crack occurrence possibility of the hydration heat attributable to the big temperature difference between middle section and bottom section of concrete was expected at bottom section concrete. Therefore, the structure above the ground like transfer girder is not applicable to consider the placing method C.

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