• Title/Summary/Keyword: 밀봉재

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Design of Reactor Coolant Purification Filter and Seal Injection Filter (원자로 냉각재 정화필터 및 밀봉수 주입필터 국산화 설계)

  • Park, Jong-Beom;Kim, Dong-Soo;Lee, Joo-Hyoung
    • Proceedings of the KIEE Conference
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    • 2000.11c
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    • pp.476-478
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    • 2000
  • Objective is to design a high performance purification filter system of reactor coolant and seal injection system at nuclear power station. The purification filter systems play an important role in the stability of the nuclear and volume control system which consist the primary network systems of the nuclear power station. But the users of the purification filter systems frequently suffer from high maintenance cost which comes from lack of understanding of the system technology and domestic suppliers. It is time to establish a high performance domestic filter system manufacturing technology and optimum design for wide use in industrial applications.

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Effect of Packaging Systems with High CO2 Treatment on the Quality Changes of Fig (Ficus carica L) during Storage (저장 중 무화과(Ficus carica L) 선도유지를 위한 고농도 이산화탄소 처리된 포장 시스템 적용 연구)

  • Kim, Jung-Soo;Chung, Dae-Sung;Lee, Youn Suk
    • Food Science and Preservation
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    • v.19 no.6
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    • pp.799-806
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    • 2012
  • This experiment was conducted to establish the optimum conditions for high $CO_2$ gas treatment in combination with a proper gas-permeable packaging film to maintain the quality of fig fruit (Ficus carica L). Among the fig fruits with different high $CO_2$ treatments, the quality change was most effectively controlled during storage in the 70%-$CO_2$-treated fig fruit. Harvested fig fruit was packaged using microperforated oriented polypropylene (MP) film to maintain the optimum gas concentrations in the headspace of packaging for the modified-atmosphere system. MP film had an oxygen transmission rate of about $10,295cm^3/m^2$/day/atm at $25^{\circ}C$. The weight loss, firmness, soluble-solid content (SSC), acidity (pH), skin color (Hunter L, a, b), and decay ratio of the fig fruits were monitored during storage at 5 and $25^{\circ}C$. The results of this study showed that the OPP film, OPP film + 70% $CO_2$, and MP film+70% $CO_2$ were highly effective in reducing the loss rate, firmness and decay occurrence rate of fig fruits that were packaged with them during storage. In the case of using treatments with packages of OPP film and OPP film+70% $CO_2$, however, adverse effects like package bursting or physiological injury of the fig may occur due to the gas pressure or long exposure to $CO_2$. Therefore, the results indicated that MP film containing 70% $CO_2$ can be used as an effective treatment to extend the freshness of fig fruits for storage at a proper low temperature.

The Structual Restoration on Gyeongju-Style Piled Stone-Type Wooden Chamber Tombs (경주식 적석목곽묘의 구조복원 재고)

  • Gweon, Yong Dae
    • Korean Journal of Heritage: History & Science
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    • v.42 no.3
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    • pp.66-87
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    • 2009
  • The definition of the structure of wooden chamber tomb(piled stone-type) is as follows. It is a tomb with wooden chamber, and stones were piled on top of the wooden chamber, and then a wooden structure was placed on top of the piled stones, and more stones were piled on top of the wooden structure, and sealed with clay. Of course this definition can vary according to periods, the buried, etc. Gyeongju-style piled stone type wooden chamber tombs have some distinguished characteristics compared to general definition of piled stone type wooden chamber tombs. Outside the wooden chamber, either stone embankments or filled-in stones were layed out, and pilet-in stones are positioned right above the wooden chamber, and almost every class used this type, and finally, it is exclusively found in Gyeongju area. First generations of this Gyeongju-style piled stone type wooden chamber tombs appeared in first half of 5th century. These tombs inherited characteristics like ground plan, wooden chamber, double chamber(inner chamber and outer chamber), piled stones, burial of the living with the dead, piled stones, from precedent wooden chamber tombs. However these tombs have explicit new characteristics which are not found in the precedent wooden chamber tombs such as stone embankments, wooden pillars, piled stones(above ground level), soil tumuluses. stone embankments and wooden pillars are exclusively found on great piled stone type above-ground level wooden chamber tombs such as the Hwangnamdaechong(皇南大塚). Stone embankments, wooden pillars, piled stones(above ground level) are all elements of building process of soil tumuluses. stone embankments support outer wall of above-ground level wooden chambers and disperse the weight of tumuluses. Wooden pillars functioned as auxiliary supports with wooden structures to prevent the collapse of stone embankments. Piled stones are consists of stones of regular size, placed on the wooden structure. And after the piled stones were sealed with clay, tumulus was built with soil. Piled stones are unique characteristics which reflects the environment of Gyeongju area. Piled stone type wooden chamber tombs are located on the vast and plain river basin of Hyeongsan river(兄山江). Which makes vast source of sands and pebbles. Therefore, tumulus of these tombs contains large amount of sands and are prone to collapse if soil tumulus was built directly on the wooden structure. Consequently, to maintain external shape of the tumulus and to prevent collapse of inner structure, piled stones and clay-sealing was made. In this way, they can prevent total collapse of the tombs even if the tumulus was washed away. The soil tumulus is a characteristic which emerges when a nation or political entity reaches certain growing stage. It can be said that after birth of a nation, growing stage follows and social structure will change, and a newly emerged ruling class starts building new tombs, instead of precedent wooden chamber tombs. In this process, soil tumulus was built and the size and structure of the tombs differ according to the ruling class. Ground plan, stone embankments, number of the persons buried alive with the dead, quantity and quality of artifacts reflect social status of the ruling class. In conclusion, Gyeongju-style piled stone type wooden chamber tombs emerged with different characteristics from the precedent wooden chamber tombs when Shilla reached growing stage.

Effects of Item Packaging Methods on the Quality Characteristics of Yukwa during Storage (단위포장 방법에 따른 유과의 저장 중 품질 특성)

  • Jang, Min Jun;Lee, Keun Taik
    • Food Science and Preservation
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    • v.20 no.2
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    • pp.158-165
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    • 2013
  • This study aimed at investigating the quality changes of Yukwa during storage using the various item packaging methods present in the domestic market. The samples consisted of a self-adhesive-oriented polypropylene (OPP) film pouch (P1), a heat-sealed OPP film pouch (P2), and a polystyrene (PS) tray with a polyethylene terephthalate (PET) lid (P3). These were stored at $25^{\circ}C$ up to eight weeks. Throughout the storage period, the acid values of all the study samples remained under the Korean hygiene regulation limit of 2.0 mg KOH/g. The P2 samples showed both the slowest decrease in water content and the slowest increase in hardness value during storage. Sensory evaluation also showed that the P2 samples were the only ones that maintained their market value of 5.0 throughout the eight-week assessment period.

The Conservation and Current Condition of the Excavated Metallic Objects (출토금속 문화재의 보존과 현황)

  • Moon, Whan Suk
    • Journal of Conservation Science
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    • v.6 no.2 s.8
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    • pp.141-148
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    • 1997
  • When we have entered high economic growth since 1970s, many archaeological excavations were performed all over the country. Excavated objects composed of variable materials are inevitably subjected to deformations owing to surrounding environments and storage conditions. Although the importance of conservation treatment of the objects is greatly increased, a few conservation laboratories are there comparing with excavation groups. The metallic objects excavated are very unstable and deformable state. So it is important not to allow iron objects, especially cast iron, to dry out once excavated. Because the corrosion reactions on the surface proceed rapidly, the objects may be destroyed at the moment. The conservation procedures of the excavated metallic objects are as follows: (1)It is stable on-site storage method for objects to keep vinyl film with envelop or to immerse alkaline solution to prevent the environmental changes. (2)The objects must be treated at once under suitable methods in the conservation laboratory after excavation. (3)The continued existence of objects depends on environmental factors such as relative humidities, regular inspection, light etc.

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Influence of Physical Property of Soft Film and Packaging Method on the Storage Stability of Individually Packaged Fresh Ginseng (연포장재 필름의 물성 및 포장방법이 개별포장한 수삼의 저장성에 미치는 영향)

  • 손현주;김은희;노길봉;정광식;김정한
    • Journal of Ginseng Research
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    • v.25 no.1
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    • pp.45-52
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    • 2001
  • The storage stability of fresh ginseng packaged individually in a soft film bag was more enhanced as the soft film with lower oxygen permeability was used, while the optimum water vapor permeability for enhancing the storage stability of fresh ginseng was estimated 3.5 g/m$^2$$.$day$.$90% RH when using the soft film with low oxygen permeability of 3.6∼5.4 cc/m$^2$$.$day$.$atm. The storage stability of the individually packaged fresh ginseng was also enhanced when the soft film bag was filled with carbon dioxide-oxygen-nitrogen (25:5:70) miked gas but the vacuum packaging exhibited little effect for the enhancement of storage stability of the fresh ginseng.

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Study on the Preparation of the Phosphoric Flame retardent for the EMC (EMC용 반응형 인계 난연 수지 개발)

  • Ahn, Tae-Kwang;Kim, Han-Byung;Ryu, Kum-Sook
    • Proceedings of the KAIS Fall Conference
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    • 2009.05a
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    • pp.372-375
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    • 2009
  • 반도체 봉지재란 실리콘 칩, 골드와이어, 리드프레임 등의 반도체 소지를 열, 수분, 충격으로부터 보호하기 위해 밀봉하는 재료로서 EMC(Epoxy Moding Compound)가 가장 많이 쓰인다. EMC는 기계적, 전기적 성능향상을 위한 무기재료로 실리카(Silica), 열에 의해 경화되어 3차원 경화구조를 형성하는 에폭시수지, 빠른 경화특성을 부여하기 위한 경화제로서의 페놀수지, 유기재료와 무기재료 사이의 결합력을 높이기 위해 커플링제, 카본블랙, 이형성 확보를 위한 왁스(Wax), 착색제(Colorant), 난연제(Flame Retardant)등의 첨가제로 구성되는 복합소재로써 본 연구에서는 에폭시의 유형에 따른 용융 실리카를 주충진재로 하여 각각의 봉지재의 첨가제를 기준으로 할 때 다양한 형태의 친환경 비할로겐계 반응형 난연제를 합성하는 기술을 개발하고 비 할로겐계 및 Sb 계 첨가형 난연제의 혼용 배합을 통해 친환경 EMC용 난연제의 제조기술을 개발하였다. 이들 EMC의 요구특성은 요구특성은 외부환경으로부터 칩 보호, 칩을 전기적으로 절연특성 유지, 칩의 작동시 발생되는 열의 효과적인 방출 특성 유지, 실장(Board Mounting)의 간편성 특성을 확보해야 하는 특성을 지니고 있어 이들 요구특성에 적합한 특성조사가 함께 이루어졌다.

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Quality Change and Weight Loss of Fresh Ginseng Individually Packaged in a Soft Film According to its Storage Condition (연포장재 필름으로 개별포장한 수삼의 저장조건에 따른 외관품질 변화 및 개체무게 감소)

  • 손현주;김은희;이성계;노길봉
    • Journal of Ginseng Research
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    • v.25 no.3
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    • pp.122-126
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    • 2001
  • Fresh ginseng was washed with water and packaged individually in a soft film bag (ONY/LDPE/L-LDPE;200${\times}$300mm, 90$\mu\textrm{m}$), then stored at 25$^{\circ}C$, 10$^{\circ}C$, or 4$^{\circ}C$ to investigate quality and weight changes of the packaged fresh ginseng according to its storage time. Softening was the major phenomenon which influenced on the quality of the packaged fresh ginseng while spoilage and color-change were relatively minor phenomena. There were very good correlations not only between the quality change rate constant and the storage temperature but between the weight change rate constant and the storage temperature. This result suggests that the shelf-life and the weight loss of the packaged fresh ginseng being store at low temperature can be estimated by an accelaerated sotrage test.

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매실의 다양한 이용을 위한 가공 저장 및 포장방법

  • 은종방;김철암;차환수
    • Food preservation and processing industry
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    • v.3 no.1
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    • pp.68-80
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    • 2004
  • 매실을 다양하게 이용하고 부가가치를 높이며 매실의 품질저하 방지 및 이용성 증대를 도모하기 위하여 실시된 지금까지의 매실의 가공, 저장 및 포장 방법에 대한 것을 조사하였다. 매실의 저온저장 시청매실은 $0\~1^{\circ}C$의 저온보다도 $5\~8^{\circ}C$에서 저온 장해가 발생하기가 쉽다고 보고되었다. 이러한 장해를 방지하기 위하여 수확직후에 $0^{\circ}C$정도의 냉수로 급속히 청매실의 품온을 저하시키면 $5\~8^{\circ}C$의 저장에서도 저온장해가 경감되고 추숙도 억제한다고 한다. 상온 CA저장 조건 하에서 청매실의 선도를 유지하기 하는데 대량으로 발생하는 에틸렌의 제거와 저산소($2\%$ 하한), 고이산화탄소($8\%$)의 가스조성이 효과적이라고 보고되었다. 청매실의 저장 중 선도유지를 위하여 청매실을 저밀도폴리에틸렌(LDPE 20${\mu}m$) 필름 봉투에 포장하여 에틸렌 제거제를 넣고 $20^{\circ}C$에 저장한 결과, 에틸렌생성량은 낮은 수준으로 유지되었고 연화에 의한 품질저하가 현저히 억제된는 것을 볼 수 있다. 그리고 MA포장(LDPE 30${\mu}m+$에틸렌제거제)에서도 청매실의 녹색유지 효과가 탁월하였고 이산화탄소 농도가 높을수록 황화가 억제된 것이 연구에 의하여 밝혀졌다. 포장재의 두께를 달리할 때 청매실의 선도유지 효과도 서로 다르게 나타난다고 보고되었다. 청매실을 두께가 다른 필름에 포장, $25^{\circ}C$에서 8일간 저장한 매실은 LDPE 20, 30 필름에 포장한 것이 저장 8일에도 녹색을 그대로 유지한 것을 보아 선도유지 효과가 있음을 알 수 있다. 그리고 중량감소은 LDPE 30, 40이 적게 나타났고 장해정도는 LDPE 20, 30 적게 나타났다. 청매실의 저장 중 선도유지가 가장 양호한 LDPE 30 포장재에 청매실과 함께 탄산가스흡수제, 에틸렌제거제를 각각 또는 혼합첨가하고 밀봉한 후 $25^{\circ}C$에서 10일간 저장한 매실은 에틸렌제거제 첨가한 것이 녹색유지효과와 선도유지효과가 좋았으며 매실의 장해발생도 가장 낮은 것으로 보고되었다. 매실을 이용하여 제조되는 가공식품으로는 매실주, 매실차, 매실 Fruit leather, 매실절임, 고추장장아찌, 매실식초, 매실잼, 매실김치 등이 있다. 앞으로 매실의 이용을 증진시키고 소비를 더욱 촉진시키기 위해서는 매실의 생리학적특성을 이해하여 더욱 효과적인 저장 및 포장방법을 개발하고 생리활성을 이용한 새로운 매실제품의 개발에 대한 연구가 뒤따라야 할 것이다.

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An Experimental Study on the Erosion of a Compacted Calcium Bentonite Block (압축된 칼슘벤토나이트 블록의 침식에 대한 실험적 연구)

  • Baik Min-Hoon;Cho Won-Jin
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.3 no.4
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    • pp.341-348
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    • 2005
  • Bentonite has been considered as a candidate buffer material in the underground repository for the disposal of high-level radioactive waste because of its low permeability, high sorption capacity, self sealing characteristics, and durability in nature. In this study, the potential for separation of bentonite particles caused by the groundwater erosion was studied experimentally for a Korean Ca-bentonite under the relevant repository conditions. Results showed that bentonite particles can be generated at the bentonite/granite interface and mobilized by the water flow although the intrusion of bentonite into fracture by swelling pressure was observed to be small. Different processes of mobilization of theses colloids from the compacted bentonite block have been identified in this study. The concentration of particles eluted in water was increased as the flow rate increased. Thus the result reveals that the erosion of the bentonite surface due to the groundwater flow together with intrusion processes is the main mechanism that can mobilize bentonite colloids in the fracture of the granite.

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