• Title/Summary/Keyword: Dry heat

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A Study on Initiating Events Identification of the IS Process

  • Cho, Nam-Chul;Jae, Moo-Sung;Eon, Yang-Joon
    • International Journal of Safety
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    • v.5 no.1
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    • pp.29-32
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    • 2006
  • There has been an increasing need for substitute energy development due to the dry up of the fossil fuel and environmental problems. Among the substitute energy under consideration, producing hydrogen from water without the accompanying release of carbon has become a promising technology. Also, Iodine-Sulfur (IS) thermochemical water decomposition is one of the promising processes that can produce hydrogen efficiently using the high temperature gas-cooled reactor (HTGR) as an energy source capable of supplying heat at over 1000. In this study, to effect an initiating events identification of the IS process, Master Logic Diagram (MLD) was used and 9 initiating events that cause a leakage of the chemical material were identified.

An Experimental Study on the Properties of Hwangtoh Mortar for the Application of Construction Material (건축적 적용을 위한 황토모르터의 물성에 관한 실험적 연구)

  • Lee, Hyun-Chul;Lee, Gun;Go, Seong-Seok
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2006.11a
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    • pp.43-46
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    • 2006
  • The Hwangtoh is one of the traditional construction material used in wall, plastering material, and ondol (Korean underfloor heating system) with stone and wood. It is an important greenness material and it has much advantages such as; high storage of heat, auto-purification, antibiotic ability, and emission of far infrared rays. But, it is not developed and not used in modern construction because of its low strength and properties of dry shrinkage crack. According to the recent researches and studies, it is evaluated for natural pozzolanic material like flyash or pozzolan. It's possibility on construction material is high because it's chemical and mineralogical proportion is like as Metakaolin and Kaolinite. In this point of view, this study aims to analyze the physical properties on Hwangtoh mortar through an experiment with various activation condition of Hwangtoh, which is natural pozzolanic material, for the purpose of increase the using possibility in construction material.

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Determining thermal comfort properties of coverall worn in the atomic power plant using a sweating thermal manikin and ISO 7730 (발한 Thermal manikin과 국제 표준 7730을 이용한 원자력 발전소 작업복의 열적 쾌적성 판별)

  • 홍성애
    • Journal of the Ergonomics Society of Korea
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    • v.15 no.1
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    • pp.91-103
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    • 1996
  • For determining thermal comfort properties of work suit in an atomic power plant, three different coverall ensembles (PVE, PET/Rayon, PP Nonwoven) were selected and the resistance to dry and evaporative heat transfer were measured for each ensemble by using a sweating thermal manikin. Also, PMV (Predicted Mean Vote) and PPD(Predicted Percentage of Dissatisfied) indices were predicted according to ISO 7730. As a result, ideal environmental conditions in an atomic power plant were suggested to make workers feel thermally comfortable. In addition, ideal intrinsic insulation values of coverall ensembles as a work suit under the present environmental conditions in the at6omic power plant were provided. The information given in this paper can be used to control environmental conditions in the atomic power plant thermally comfortable and to select a proper work suit for providing thermal comfort to the workers.

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Crack Properties of Concrete depending on Changes in Surface-Covered Curing Materials in Hot Weather (서중환경에서 표면피복 양생재 변화에 따른 콘크리트의 균열특성)

  • Lee, Je-Hyun;Kim, Tae-Woo;Baek, Cheol;Lee, Sang-Un;Han, Min-Cheol;Han, Cheon-Goo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2017.11a
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    • pp.175-176
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    • 2017
  • Many problems in various aspects such as generation of plastic/dry contraction cracks and cold joints can be caused unless proper quality control measures are established in hot weather circumstances. Therefore, this study aimed to compare the crack patterns of concrete by applying a change in 3 surface curing methods such as a mono aluminum-deposited bubble sheet developed to reduce the temperature and cracks through reflection of heat in summer and a PE film and a surface exposure used generally to an actually constructed apartment slab. The study result confirmed that the best concrete crack reduction effect can be obtained with a mono aluminum-deposited bubble sheet.

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Thermal Conductivity Properties of Adsorption Matrix According to Silica Gel (실리카겔을 활용한 흡착 경화체의 열전도율 특성)

  • Gwon, Oh-Han;Lim, Hyun-Ung;Lee, Dong-Hoon;Lee, Sang-Soo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2017.11a
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    • pp.109-110
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    • 2017
  • In recent years, it has been urgently required to develop and study a product that adsorbs and reduces lardon gas due to the risk of lardon gas in Korea. Therefore, this study develops a board for adsorbing lardon gas into the inside and outside of the room. The thermal conductivity was measured in order to carry out an adiabatic test for satisfying the following conditions. Experimental level and factors were substituted with silica gel. In addition, silica gel was used by dry mixing and prewetting, and 10, 20, and 30% of cement was substituted for each. As a result of the test, the thermal conductivity decreased to 0.45 W/mK with increasing the amount of replacement, and reached a similar level when compared with diatomite.

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A Study on Recycling of Waste Tire (폐타이어 재 자원화를 위한 연구)

  • 이석일
    • Journal of Environmental Health Sciences
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    • v.26 no.4
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    • pp.38-44
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    • 2000
  • Compared to other waste, waste tire has much discharge quantity and calorie. When we use waste heat from waste tire, it can be definitely better substitute energy than coal and anthracite in high oil price age. To use as a basic data for providing low cost and highly effective heating system, following conclusion was founded. Annual waste tire production was 19,596 million in 1999, Recycling ratio was almost 55% and more than 8.78 million was stored. Waste tire has lower than 1.5% sulfur contain ratio which is resource of an pollution, So it is a waste fuel which can be combustion based on current exhaust standard value without any extra SOx exclusion materials. Waste tire has 9,256Kcal/kg calorific value and it is higher than waste rubber, waste rubber, waste energy as same as B-C oil. When primary and second air quantity was 1.6, 8.0 Nm$^3$/min, dry gas production time was 270min and total combustion time was 360 min. In the SOx, NOx, HC of air pollution material density were lower than exhaust standard value at the back of cyclone and dusty than exhaust standard value without dust collector.

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Improving Strength in Casting Mold by Control of Starting Material and Process

  • Cho, Geun-Ho;Kim, Eun-Hee;Jung, Yeon-Gil
    • Journal of the Korean Ceramic Society
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    • v.53 no.5
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    • pp.541-547
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    • 2016
  • In developing high temperature molds with advantages of the sand and precision (investment) castings, mechanical properties of the mold were improved through homogeneous coating of starting powders with an inorganic binder and improvement of fabrication process. Beads with mullite composition were employed for properties of the mold under high temperature, which was compared with artificial sands. Precursors of silica and sodium oxide were used as starting materials for an inorganic binder to achieve homogeneous coating on the starting powders. Strength was enhanced by the glass phase converted from the inorganic binder through heat treatment process. Also, two kinds of process, wet and dry processes, were incorporated to prepare mold specimens. Consequently, fabrication process of the mold with superior strength and high temperature applicability, compared with the previous molds for sand casting, could be suggested through control of the starting material and enhancement of the vitrification efficiency.

Processing and Properties of Steel Foam Sandwiches

  • Lefebvre, Louis-Philippe;Gauthier, Maxime;Baril, Eric;Voizelle, Benoit
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 2006.09a
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    • pp.91-92
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    • 2006
  • Metallic foams have a combination of attractive properties such as high specific mechanical properties and good energy absorption characteristics. This paper presents the properties of steel foam sandwiches produced using powder metallurgy approach. Metallic powder, solid polymeric binder and a foaming agent are dry-mixed and molded into the desired shape. The molded powder mix is then heat-treated to foam, debind and sinter the material. The resulting material has an open cell structure with high porosity. The structure and properties of sandwiches specimens produced with the process are presented and discussed.

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A study of oriental medical treatments for diabetic nephropathy (당뇨병성 신증의 한의학적 접근 및 치료에 대한 연구)

  • Kang, Yoon-Ho;Kim, Sung-A
    • Journal of the Korean Institute of Oriental Medical Informatics
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    • v.11 no.2
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    • pp.1-13
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    • 2005
  • Objectives To research oriental medical treatments for diabetic nephropathy by literature study Methods We reviewed oriental medical book concerning the diabetic nephropathy. Results & Conclusions 1. The diabetic nephropathy has relation to edema, dizziness, exhaustion of strenght, obstruction and rejection among the transformations of emaciation and thirst. 2. The causes of diabetic nephropathy are dry heat caused congenital defect, mental depression and greasy diet damages liquid nutrients and thereafter Gi and Yang deficiency produces blood stagnation, dampness and phlegm-turbidity. 3. The medical treatments are invigorating Gi, promoting blood flow to remove blood stasis and removing dampness through diuresis. The frequently used herb are Radix Astragali, Poria, Fructus Corni, Rhizoma Dioscoreae, Radix Salviae Miltiorrhizae, etc. and Dansam is meanigfull of all herbs for invigorating blood and dispelling blood stagnation.

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A Surface Study of 304 and 316 Stainless Steel Oxidized between $300^{\circ}C$ and $500^{\circ}C$ ($300^{\circ}C$$500^{\circ}C$사이에서 산회된 304, 316 스테인리스강의 표면특성)

  • 김경록;이경구;강창석;최답천;이도재
    • Journal of the Korean institute of surface engineering
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    • v.32 no.1
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    • pp.43-48
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    • 1999
  • Oxidation behavior of 304 and 316 stainless steels was studied. After solution heat treatment, specimens were polished up to 1$mu \textrm{m}$ using $Al_2O_3$ powder and then subjected to oxidation between $300^{\circ}C$ and 50$0^{\circ}C$ in dry air. TEM and EDS were used for analyzing the components and structure of oxide film. TEM analysis of oxide film revealed that thin amorphous Fe oxide ($Fe_2O_3$) was formed on the top of surface while polycrystalline (Cr, $Fe_2O_3$ was formed below the amorphous Fe oxide layer. The specimens oxidized at $500^{\circ}C$ showed that 316 stainless steel had higher oxidation resistance than 304 stainless steel. These results suggest that Mo component of 316 stainless steel suppresses the formation of Cr carbide which may result in a local Cr depleted area.

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