• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.11
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• pp.595-601
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• 2020

During the safety inspection of nitrocellulose-made explosive containers stored for more than 10 years, cracks were found in the containers. Therefore, a failure cause analysis test was performed. First, the cause of failure through the failure tree analysis was conducted to select the factors that influenced failure. The changes in the properties of the container caused by the acceleration of the reaction were found to be the cause of the failure by confirming the influence on the environment and internal/external factors that may occur during storage. To confirm this, environmental tests, such as thermal shock test and vacuum thermal stability test, were performed using a naturally aged container to analyze the cause of failure, and an accelerated aging test was performed to reproduce the failure. Through this, the chemical reaction was accelerated by heat and charge, as in the result of the fault tree analysis, and it was confirmed that the physical properties of the container were changed. In addition, the service life of the container was estimated using the Arrhenius model for the storage life due to thermal aging.

• KAPE Magazine
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• s.207
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• pp.8-9
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• 2013

• Journal of the Korea Organic Resources Recycling Association
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• v.6 no.2
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• pp.113-129
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• 1998

To suggest the separate collection system of garbage in household, people's disposition was evaluated. It was indicated that garbage be collected daily to minimize the odor which was major nuisance from garbage. However, most people wanted to discharge garbage in two or three days interval, as they did not prefer frequent handling. So, proper size of garbage container was determined as two to three days capacity. In contrast with it, it was major opinion that dicharged garbage should be collected everyday by local government to eliminate the outdoor pollution. Plastic bag was the most popular container, as it could be used instantly. Price of the bag affected on the efficiency of reduction and separate collection of garbage. Low price increased the separate collection and decreased the reduction, while high price introduced the opposite result. So, the dual price system was suggested to enhance both objectives.

• Journal of Technologic Dentistry
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• v.30 no.1
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• pp.149-153
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• 2008

1. 석고를 보관할 때는 건조한 곳에 밀봉하여 보관해야 한다. 따라서 용기 포장을 일단 개봉하면 밀봉용기에 담아 보관하는 것이 바람직하다. 2. 혼수비는 석고의 기계적 성질에 영향을 주기 때문에 정상적인 혼수비를 지켜야 하며, 모형은 경화된 후에도 물과 닿지 않도록 주의한다. 3. rubber인상재의 경우 비눗물을 붓이나 스프레이타입으로 뿌려준 후 흐르는 물에 씻고, 물기를 제거한 후 석고를 주입하면 기포 발생을 줄일 수 있다. 4. 석고를 인상체내에 너무 높이 올려쌓아도 무게로 인해 변형 된다. 5. 석고가 tray밖으로 흘러나가도 변형된다. (공기와 접촉되어 경화된 석고가 아직 경화되지 않은 석고를 잡아당김.) 6. 인상체에서 분리한 모형은 요오드 스프레이를 제조자 설명서에 따라 뿌려 소독한다. 7. 교합기에 모형 부착 시 base끼리 bar나 성냥개비등 다른 고정장치로 고정 시켜야하고, 교합기를 위에서 눌러주어야 한다. 그렇지 않을시 교합관계가 높아질 수 있다. 8. 재료를 구입시 물리적 특성이 많이 기재되어 있는 제품을 선택한다.

• Life and Agrochemicals
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• s.252
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• pp.24-27
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• 2009

농업인이 첨단 자재인 농약사용을 망설이거나 소비자가 우리 농산물이 안전한지 아닌지를 의심하는 것만큼 불행한 현실은 없다. 농업인은 올바른 사용 및 보관법을 준수하여 대소의 사로를 예방해야 하면 소비자는 농업 여건과 방제해야 하는 현실을 시인하고 이해해야 한다.

• 방재와보험
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• s.118
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• pp.48-51
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• 2007

본 고에서는 상온일 때 액체상태가 됨에 따라 포화증기압이 1bar 이하가 되는 물질의 보관에 대해 알아보고자 한다. 대체적으로 증류된 석유제품들(가솔린, 나프타, 케로신, 디젤이 그러하다. Zalosh의 '산업화재 예방공학(Indusrtial Fire Protection Engineering)' 과 Crowl의 '폭발의 이해(Understanding Explosions)' 를 통해 많이 다루어져왔던 내용이다.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.11a
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• pp.276-282
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• 1996

일체형원자로는 노심, 증기발생기, 가압기, 펌프 등 1차측 주기기들을 하나의 압력용기안에 모두 포함하고 있고, 또 1차측 냉각재가 원자로 안에서만 순환하므로 기존의 분리형원자로에 비해 구조특성상 대용량 원자로 냉각재 상실사고(LBLOCA)의 발생 가능성을 원천적으로 제거할 수 있다. 반면 원자로 냉각재의 보충 등을 위한 소형 배관의 파단 가능성은 역시 존재하므로 소용량 원자로 냉각재 상실 사고(SBLOCA)는 여전히 존재한다. 따라서 현재 한국원자력연구소에서 연구 개발중인 중소규모 전력생산 및 열 활용 목적의 일체형 원자로에는, 원자로 압력용기 외부에 별도의 압력용기(안전용기)를 설치하여 SBLOCA시 원자로 압력용기로부터 방출되는 냉각수를 안전 용기내에 보관하도록 함으로써 사고시 외부로의 방사성 물질 유출 가능성을 획기적으로 줄 일수 있는 설계 개념을 도입하고 있다. 본 논문에서는 안전용기의 설계시 효율적인 냉각방식에 대한 열유체 해석적 접근을 시도하였고, 예비개념설계된 일체형 열병합원자로의 설계상의 특징들 및 안전용기 설계시 앞으로의 연구방향 등도 간략히 소개하였다.

• The korean journal of orthodontics
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• v.27 no.6 s.65
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• pp.979-995
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• 1997

The purpose of this study was to identify the preventive and the progressive inhibitory effects of enamel demineralization with fluoride releasing light-and self-cured orthodontic sealants(FluoroBond), in vitro, under the polarizing light microscope and the scanning electon microscope. The polarizing light microscopic group was subdivided into seven groups(Group A-Group G). The scanning electron microscopic group was also subdivided into seven groups(Group A'-Goup G'). For polarizing light microscopic evaluation, longitudinal sections were made longitudinally by Maruto cutter(Maruto Co., Japan) and Maruto grinding machine(Maruto Co., Japan). Sections were examined and photographed by the polarizing light microscope(Olympus Optical Co., Japan) using crossed polars and with the enamel rod longitudinal axis oriented at $45^{\circ}$ to the extinction position. For scanning electron microscopic evaluation, the specimens were coated with a highly conducting layer of gold palladium in a model Hus-4 high-vacuum evaporator and examined in an ISI-100B scanning electron microcope operated at 20kV. The results of this study were as follows : 1. The mean depths of artificial carious lesions under a polarized light microscope were $Group\;A(5.08{\mu}m),\;Group\;B(47.82{\mu}m,\;Group\;C(8.42{\mu}m),\;Group\;D(7.20{\mu}m),\;Group\;E(85.41{\mu}m),\;Group\;F(60.38{\mu}m),\;Group\;G(60.13{\mu}m)$. 2. There were statistically significant differences in Group B compared with Group A, C, and D(p<0.05), and also, in Group I compared with Group F and Group G(p<0.05). 3. Light-and self-cured orthodontic sealants had the preventive effects of enamel demineralization. 4. Light-and self-cured orthodontic sealants had the progressive inhibitory effects of enamel demineralization. 5. The time progress of demineralizing agent had no influence on the samples of light-and self-cured orthodontic sealants under the scanning electron microscope. 6. There was no difference between the specimens of light-and self-cured orthodontic sealants both in the polarized light microscopic group and in the scanning electron microscopic group.

• Journal of Climate Change Research
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• v.2 no.4
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• pp.309-316
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• 2011

The study evaluated the loss rate of carbon dioxide, which is the prevalent greenhouse gas, according to the method of keeping specimens using standard gases. In order to examine the difference generated by a bag of storing specimens, it checked the loss rate according to concentration and time by making a 2nd set of standard gases in a Tedlar bag and an Aluminium bag. The containers lost gases at a rate of 5% or more after 6 day, and 10% or more after 15 days in both bags. In time, it was confirmed that the loss rate of the Aluminium bag was higher than that of the Tedlar bag. Specifically, there was no significant difference between the two bags after 12 days had passed, but by the 15th day, it was confirmed that the loss in an Aluminium bag was more severe than that in the Tedlar bag. The study went on to check the relations between the humidity in storage and the loss rate. The results showed that there was no significant effect of humidity on the loss rate until 72 hours had passed, when the loss rate in the Tedlar bag with high humidity was about 5% higher than that of the Tedlar bag in dry conditions. This study examined the loss rate of carbon dioxide, a typical greenhouse gas. It is important to note that the loss rate was determined by calculating highly reliable carbon dioxide emission and emission coefficient data, with consideration to the method of keeping specimens.

• Analytical Science and Technology
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• v.35 no.3
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• pp.116-123
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• 2022

Polymer bags, metallic canisters, and glass bottles have been used as containers for analyzing the volatile organic compounds (VOCs) in air. In this study, various sampling containers were compared to investigate the short-term stability of VOCs, that is, from the time they are sampled to the time they are analyzed. Polyvinyl fluoride (PVF), polypropylene (PP), polyester aluminum (PE-Al) bags, canisters, and glass bottles were used as sample containers. A 100 nmol/mol standard gas mixture of benzene, toluene, ethylbenzene, m-xylene, styrene, and o-xylene was used for the VOC comparison. Changes in the concentrations of samples stored for 10~20 day in each container were measured using a thermal desorption-gas chromatograph-flame ionization detector (TD-GC-FID). As a result, VOCs stored in a canister and two kinds of amber glass bottles have shown immaterial decreases in concentration in one week, and more than 80 % of the initial concentration was maintained for two weeks. In the case of polymer bags, the concentration of all VOCs, except benzene and toluene, were remarkably decreased below 70% of the initial concentration in one day. Particularly, ethylbenzene, xylene, and styrene have shown dramatic decreases in concentration below 30 % of the initial concentration in all polymer bags in one day.