• Title/Summary/Keyword: storage condition

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HEAT REMOVAL TEST USING A HALF SCALE STORAGE CASK

  • Bang, K.S.;Lee, J.C.;Seo, K.S.;Cho, C.H.;Lee, S.J.;Kim, J.M.
    • Nuclear Engineering and Technology
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    • v.39 no.2
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    • pp.143-148
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    • 2007
  • Spent nuclear fuel generated at nuclear power plants must be safely stored during interim storage periods. A dry storage cask to safely store the spent nuclear fuel should be able to adequately emit the decay heat from the spent nuclear fuel. Therefore, heat removal tests using a half scale dry storage cask have been performed to estimate the heat transfer characteristics of a dry storage cask under normal, off-normal, and accident conditions. In the normal condition, the heat transfer rate to an ambient atmosphere by convective air through a passive heat removal system reached 83%. Accordingly, the passive heat removal system is designed well and works adequately. In the off-normal condition, the influence of a half blockage in the inlet on the temperature appears minimal. In the accident condition, the temperature rose for 12 hours after the accident, but the temperature rise steadied after 36 hours.

A STUDY ON SURFACE HARDNESS OF COMPOSITE RESINS ACCORDING TO STORAGE CONDITON AND HEAT TREATMENT (보관조건과 열처리에 따른 복합레진의 표면경도에 관한 연구)

  • Kang, Seung-Hoon;Min, Byung-Soon
    • Restorative Dentistry and Endodontics
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    • v.19 no.1
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    • pp.194-204
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    • 1994
  • The purpose of this study was to evaluate the surface hardness of composite resins according to heat treatment. storage condition and storage time. In this study. two kinds of composite resin inlays and one kind of conventional posterior composite resin were used as experimental materials. One hundred eighty composite resin specimens were constructed from composite resin inlays and conventional posterior composite resin. The conditions of this study were heat treatment. storage condition and storage time. Hardness readings were taken from the top surface of each samples using the Vickers microhardness tester(MHT-l. Matsuzawa. Japan}. The following results from this study were obtained: 1. Regardless of storage condition. both composite resin inlay and conventional posterior composite resin have a higher surface hardness under heat treatment than not. 2. Composite resins with heat treatment have a higher surface hardness under dry storage than under water immersion. 3. In case of Clearfil Photo Posterior and Brilliant Enamel with heat treatment. there was no significant difference with time. but Clearfil CR Inlay with heat treatment. there was statistical difference after 24 hours. 4. Surface hardness of composite resins with coarse hybrid type was higher than that of composite resin with fine hybrid type.

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A Development of Representative Condition Evaluation Standard for LNG Storage Tank Structures (LNG 저장탱크 구조물의 종합적 상태평가기준 개발)

  • Kim, Jung-Hoon;Jo, Young-Do
    • Journal of the Korean Institute of Gas
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    • v.22 no.6
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    • pp.44-51
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    • 2018
  • As the LNG storage tank is aged, if there is a crack in the outer wall concrete or corrosion of the reinforcing steel, there is a risk of a major accident such as collapse of the structure depending on the type and degree of damage. Since 2014, LNG storage tanks have undergone precise safety diagnosis and safety inspection has been carried out. The condition evaluation criteria for each component have been revised and applied in January 2016. The condition evaluation standard is to evaluate the status of storage tanks based on the appearance survey and material test results of LNG storage tanks and it is important for maintenance. In addition, the representative condition evaluation standard that shows the comprehensive state of each LNG storage tank is important in maintenance, but the related standard for LNG storage tank outer concrete is not available in Korea and abroad, and development of the condition evaluation standard is necessary. In this paper, we examined the structural characteristics of LNG storage tanks, analyzed the status of the condition evaluation criteria for each member, and developed a comprehensive status rating system by weighting the members. We used the AHP(Analytic Hierarchy Process) technique and developed a representative conditon evaluation criteria through surveys of professional organizations.

A Study on the Storage of Fresh Fruits and Vegetables (I) -Changes of the Internal Atmosphere in Storage Room and the Biochemical Changes of Apple Fruits by Controlled Ventilation- (청과물 저장에 관한 연구(제1보) -통기량 조절에 따른 저장실내 기체조성 및 생리화학적 변화에 대하여-)

  • Sohn, Tae-Hwa;Choi, Jong-Uck;Kim, Sung-Dal
    • Korean Journal of Food Science and Technology
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    • v.4 no.1
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    • pp.13-17
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    • 1972
  • This experiment was conducted to observe the changes of composition of atmosphere in storage room by controlled ventilation under normal and sub-atmospheric conditions, and the biochemical changes in apple texture under these conditions. The results were as follows; 1) By controlled ventilation, concentration of carbon dioxide in storage room was optionally regulated and constantly maintained. 2) Among compositions of internal atmosphere of apple, especially, concentration of ethylene was much decreased at apple stored under sub-atmospheric condition than that stored under normal atmospheric condition. 3) Acidity of apple stored under sub-atmospheric condition was much greater than that of apple stored under normal atmospheric condition. 4) Respiratory quotients of apple, which was stored under normal and sub-atmospheric conditions, were shown to be high. But decarboxylation of added pyruvate was found more active in slices prepared from apple stored under sub-atmospheric condition.

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The Influences of Temperature and Humidity in Storage Room, Moisture Content and Packing Weight of Leaf on the Carbonization of Processed Flue-cured Leaf Tobacco (저장실의 온습도, 제통수분함량 및 제통중량이 황색종 가공엽의 탄화에 미치는 영향)

  • 김상범;안동명;이윤환;김용규;복진영
    • Journal of the Korean Society of Tobacco Science
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    • v.23 no.1
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    • pp.19-30
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    • 2001
  • This study was carried out to investigate the influences of environmental condition in storage room, moisture content and packing weight of leaf on the carbonization of processed flue-cured leaf tobacco, and find out a regression model able to pre-estimate the degree of carbonization. The influence of temperature and humidity in storage room on the carbonization was high,, while that of packing weight was relatively low, However, high moisture content and packing weight of leaf accelerated the carbonization under the high temperature and humidity condition. Thus the leaf tobacco under the condition of 4$0^{\circ}C$, 7$0^{\circ}C$ R.H. in storage room, 16% moisture content and 286 kg/box of packing weight could be carbonized within one month. The pH, total sugar content, lightness(L) and yellowness(b) of leaf were closely related to carbonization of leaf during storage. There were significant regression and yellowness of leaf. It is considered that the certification and/or pre-estimation of carbonization during storage may be possible by applying the regression equation.

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Effect of Thermal Processing and Packaging Materials on Microbial Growth of Vacuum Packaged a Meat Product during Storage (진공포장한 육류제품의 열가공처리와 포장재질에 따른 저장중의 미생물성장 효과)

  • Lee, Chong-Hyun
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.4 no.1
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    • pp.33-40
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    • 1997
  • The microbial growth of fresh, vacuum packaged, cook-in-bag uncured beef patties was determined in two film structures, a commercial (PE/EVOH), and super barrier ($SiO_2$ coated polyester) material. Packaged samples were cooked to internal temperature of 71 and $82^{\circ}C$ for 30 minutes, and stored in temperature abused ($23{\pm}2^{\circ}C$) and refrigerated storage ($4-6^{\circ}C$). Barrier properties had a significant effect (p<0.001) on aerobic and mesophilic growth in the abused condition. Cooking temperatures had a statistically significant effect (p<0.05) on aerobic growth in the refrigerated condition. The growth of anaerobes and psychrophiles were not significantly effected by either variables. Storage times had the most significant effect (p<0.001) for all groups of microorganisms. The physical properties of the commercial film (strength, thickness, and shrinkage) were changed after exposure to thermal treatment, while the super barrier package had actually no change.

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Determination of an LNT Regeneration Condition Based on a NOx Storage Fraction in a 2.2L Direct Injection Diesel Engine (2.2L 디젤 엔진에서 NOx 흡장률 기반 LNT 재생 조건 결정)

  • Chun, Bongsu;Lee, Jungwoo;Han, Manbae
    • Transactions of the Korean Society of Automotive Engineers
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    • v.24 no.3
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    • pp.345-351
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    • 2016
  • This study was carried out to determine an optimal lean $NO_x$ trap (LNT) regeneration condition based on a $NO_x$ storage fraction. The LNT regeneration was performed by an in-cylinder post fuel injection method. A $NO_x$ storage fraction is defined by the ratio of current cumulated $NO_x$ amount in the LNT to the $NO_x$ storage capacity: 0 means empty and 1 fully loaded. In this study five engine operating conditions were chosen to represent the New European Driving Cycle. With various $NO_x$ storage fractions each engine operating condition, the LNT regeneration was executed and then $NO_x$ conversion efficiency, additional fuel consumption, CO and THC slip, peak catalyst temperature were measured. The results showed that there exist an optimal condition to regenerate the LNT, eg. 1500 rpm 6 bar BMEP with below 0.7 $NO_x$ storage fraction in this experimental constraint.

Changes of egg Quality according to eggshell treatment and storage condition (계란의 난각 처리와 보관 방법에 따른 품질 변화)

  • Lee Sung-Mo;Hong Chong-Hae
    • Korean Journal of Veterinary Service
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    • v.28 no.3
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    • pp.225-234
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    • 2005
  • Egg has been considered as one of the most important food sources in both nutritionally and economically. However, because the hazards of egg flow chains' complexity from producers to consumers and the insufficiency of cold chain systems in Korea are still remained, preventive measures for egg safety should be established. This experiment was carried out to investigate the changes of egg qualify during storage in order to find out the proper storage condition and eggshell treatment. Eggs were stored at cold condition $(5^{\circ}C,\;relative\;humidity;\;RH:\;65\pm3\%)$ and room Condition $(1st: Sep\; 6\~Nov\; 15,\;2001,\; 10\~30^{\circ}C,\;RH\;41\~86\%,\;2nd;\; Dec\;13,\;2001\~Feb\;21,\;2002,\;4\~23^{\circ}C,\;RH\;36\~89\%)$ after eggshell treatment (unwashed, washed and coated egg) during'10 weeks and examined weight loss and interior quality periodically. Weight loss was in decreasing order room washed > room unwashed > cold washed > cold unwashed > room coated > cold coated egg. And, Haugh unit was decreasing order room washed > room unwashed > room coated > cold washed > cold unwashed > cold coated egg. Our findings show that both coated eggs and refrigeration reduces the rate of decline in Haugh units and egg weight. And, washed eggs had lower average Haugh units and a higher weight loss than any of the eggshell treatment in both storage conditions. Conclusively, for washing eggshell, 150 ppm of sodium hypochlorite, regular exchange and temperature control of water should be consistent and also eggs should be dried immediately after washing. Also, national guidelines for temperature and moisture of storage places, transportation and expiration data should be established to keep quality and weight loss of eggs. Storage temperature that is a critical factor in the quality and safety of eggs should be kept under 12'c and labelling of expiration date should be obligatory.

A Study on the Improvement of Storage Environment in Museums -With Research on Actual State of Storage in Domestic Museums- (박물관 수장부문의 환경개선에 관한 연구 -국내 박물관 수장고 실태조사를 중심으로-)

  • 임채진;정성욱
    • Korean Institute of Interior Design Journal
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    • no.25
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    • pp.253-261
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    • 2000
  • Except the time when the relics of the museum are exhibited or loaned to the public, they are stored in a storage. Therefore, the environmental condition of a storage is a important factor. But in Korea, the appearance of the building and exhibition design are emphasized more than any other factors in planing museums, so the preservation technology has not yet reached the appropriate level and leaded to some environmental problem in the museum storage. The purpose of this study is to suggest guideline for an apt storage system by reconsidering practical notes in planning storage and give a efficient long-term plans examinable category. So this study based on the research had been stated from the recognition that the relics should be planned and placed differently in sorts, and developed this by researching the theory related to the matter throughout documents and to cope with the low efficiency in its essential role compared to the massive investment and through on-the-spot surveys emphasizing on the storage of the domestic museums in progress since 1995. Hereafter it compares the actual condition and problems of the domestic museum planning with the ones abroad, and analyzes the characteristic and difference between the two, and then establish an organized storage system.

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