• Title/Summary/Keyword: Harmful material

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Evaluation on the buffer temperature by thermal conductivity of gap-filling material in a high-level radioactive waste repository

  • Seok Yoon;Min-Jun Kim ;Seeun Chang ;Gi-Jun Lee
    • Nuclear Engineering and Technology
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    • v.54 no.11
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    • pp.4005-4012
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    • 2022
  • As high-level radioactive waste (HLW) generated from nuclear power plants is harmful to the human body, it must be safely disposed of by an engineered barrier system consisting of disposal canisters and buffer and backfill materials. A gap exists between the canister and buffer material in a HLW repository and between the buffer material and natural rock-this gap may reduce the water-blocking ability and heat transfer efficiency of the engineered barrier materials. Herein, the basic characteristics and thermal properties of granular bentonite, a candidate gap-filling material, were investigated, and their effects on the temperature change of the buffer material were analyzed numerically. Heat transfer by air conduction and convection in the gap were considered simultaneously. Moreover, by applying the Korean reference disposal system, changes in the properties of the buffer material were derived, and the basic design of the engineered barrier system was presented according to the gap filling material (GFM). The findings showed that a GFM with high initial thermal conductivity must be filled in the space between the buffer material and rock. Moreover, the target dry density of the buffer material varied according to the initial wet density, specific gravity, and water content values of the GFM.

An Exploratory Study of Material Flow Cost Accounting: A Case of Coal-Fired Thermal Power Plants in Vietnam

  • NGUYEN, To Tam
    • The Journal of Asian Finance, Economics and Business
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    • v.9 no.5
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    • pp.475-486
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    • 2022
  • The purpose of this paper is to examine the use of material flow cost accounting (MFCA) in Vietnam's coal-fired thermal power plants. This study is based on the contingency and system theories to explain the application of management tools and analyze steps of input, output, and process in manufacturing. Costs in producing process-based MFCA include material cost, energy cost, system cost, and waste management cost. The exploratory case study methodology is used to describe and answer two questions, namely "How coal flow cost is recognized?" and "Why waste in material consumption can be harmful to the environment?". By analyzing the Quang Ninh and Pha Lai coal-fired thermal power plants that are the typical plants, this paper identifies the flow of primary material in these plants as a basis for determining losses for the business. The material flow of coal-fired thermal power plants provides the basis for the use of the MFCA. The manufacturing of electrical items in these plants is divided into four stages, each with its own set of losses. As a result, some phases in the application of MFCA are suggested, as well as some other elements required for MFCA application in coal-fired thermal power plants.

A Study on the Surface Deterioration Evaluation of Epoxy Resin Coating as Anticorrosive Material of Concrete Water Tank Using Ozone($O_3$) (오존 정수처리 음용수조 구조물에 사용하는 에폭시 수지 방수.방식재의 표면특성 평가)

  • 오상근;강효진;곽규성
    • Proceedings of the Korea Concrete Institute Conference
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    • 2003.11a
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    • pp.513-518
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    • 2003
  • Recently, advanced systems for water treatment are introduced for water quality improvement. One of those systems is water treatment method using ozone($O_3$). For it has strong oxidizing energy, it is necessary to have materisl stability against $O_3$. In this paper, epoxy resin specimens using as anticorrosive material of concrete structure for drink water are used to serve as a material of deterioration evaluation. It is to be studied weight loss, surface corrosion of specimens, ingredient analysis of floating particle, a solute of chemical ingredient by way of accelerated ozone testing. As the results of experiment, specimen weight is decreased. The surface of specimen is eroded heavily and showed a loss of gloss and floating particle, and in the stability for drinking water, harmful ingredient is not detected in the water.

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A Study on the Fire Safety Performance of Interior Surface Materials in a Building (건축물의 실내건축 재료에 관한 화재안전성 연구)

  • Seo, Su-Eun;Shin, Seung-Woo
    • Proceedings of the Safety Management and Science Conference
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    • 2013.11a
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    • pp.275-290
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    • 2013
  • The main cause of building fire fatalities occur in the combustible material heat, smoke and toxic gases are. Building interior decoration, etc., especially as much of the harmful substances generated during combustion, and, used in domestic architecture wallpaper, ceiling, and other plastics, built-in foam insulation also analyzed recognition of fire hazards approach to test the conkalrorimiteo test, choedaeyeolbangchulryul through, chongbal heat, mass loss rate, generates carbon monoxide gas hazard ratio tests, analysis and evaluation rigid foam index testing the toxicity of hazardous material generated by performing a gas clean up and assess the material test results, the minimum order to provide data to quantify the risk of fire. Ensure fire safety of building materials, composite materials in order to test the various risk factors could be considered organic to the introduction of testing and evaluation is needed urgently.

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Experimental Study on Application of Paste-like Grouting Material to Void (공동부 충전재로써 페이스트형 유동화토의 환경 안정성 평가에 관한 실험적 연구)

  • Kim, Jin-Chun;Kang, Hee-Jin;Lim, Yu-Jin
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.10a
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    • pp.1063-1068
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    • 2008
  • When construction of high pressure jet-grouting is to be performed, it has been reported that applied cement slurry which hasn't got dried out can cause severe environmental pollution, and can flow into near streams and fish farms. Several laboratory tests were performed in this study in order to verify safety of paste-like grouting material that was developed newly to be applied to void in the ground. According to experimental test results, it is proved to be so safe that application of the newly developed flowable grouting material can prevent the materials from spilling into surrounding areas and is not harmful to fishes.

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Real-time Chemical Monitoring System using RGB Sensor toward PCB Manufacturing (PCB 제조공정을 위한 화학약품 용액의 실시간 모니터링 시스템)

  • An, Jong-Hwan;Lee, Seok-Jun;Kim, Lee-Chui;Hong, Sang-Jeen
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.21 no.5
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    • pp.397-401
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    • 2008
  • Most of the topic in PCB industry was about increasing the volume of product for the development of electronics in numerous industrial application area. However, it has been emerged that yield improvement quality manufacturing via detecting any suspicious process in order to minimize the scrapped product and material waste. In addition, recently, restriction of hazardous substances (RoHS) claims that electronic manufacturing environment should reduce the harmful chemicals usage, thus the importance of monitoring copper etchant and detecting any mis-processing is crucial for electronics manufacturing. In this paper, we have developed real-time chemical monitoring system using RGB sensor, which is simpler but more accurate method than commercially utilized oxidation reduction potential (ORP) technique. The developed Cu etchant monitoring system can further be utilized for copper interconnect process in future nano-semiconductor process.

Formaldehyde Deodorization Effect and Far-Infrared Emission Characteristics of Ceramics Prepared with Sawdust, Risk Husk, and Charcoal: Effect of Material Mixing Ratio

  • HWANG, Jung-Woo;OH, Seung-Won
    • Journal of the Korean Wood Science and Technology
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    • v.50 no.2
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    • pp.104-112
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    • 2022
  • Indoor air quality is a very important environmental factor in modern society. However, air pollutants generated from various interior construction materials significantly affect the human body, including formaldehyde (HCHO) and volatile organic compounds that threaten public health by deteriorating indoor air quality. Effective in removing these harmful substances are porous materials, such as woodceramics. In this study, charcoal, a porous material, was added to rice husk, an agricultural by-product, and sawdust generated during the sawing process to prepare boards and ceramics at different mixing ratios, and the HCHO deodorization performance and far-infrared emission characteristics were measured. As the mixing ratio of charcoal increased, the deodorization rate of the boards and ceramics tended to increase. Overall, the deodorization rate was measured to be 80% to 90%, indicating that the boards and ceramics prepared with charcoal are suitable to be used for the purpose of deodorization. The effect of the material mixing ratio on far-infrared emissivity and emission power was insignificant.

Mechanical Properties of Self-Healing Mortar Using Cementitious Material-Based Capsule (시멘트계 재료 기반 캡슐을 사용한 자기치유 모르타르의 역학 특성)

  • Lee, Jae-In;Im, Soo-Bin;Na, Bum-Su;Kim, Chae-Young;Yoon, Joo-Hoo;Choi, Se-Jin
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2023.05a
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    • pp.149-150
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    • 2023
  • Although concrete is a material widely used in the construction industry, it is very vulnerable to cracking and has a disadvantage in that durability deteriorates when cracks occur. When cracks occur, harmful factors are introduced through the micro-cracks of the structure, reducing durability. Therefore, in this study, as part of a study to alleviate the problems of maintenance and durability deterioration due to cracks in concrete structures, the mechanical properties of self-healing mortar according to the size of the capsule made of cement material were reviewed.

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Analysis of General Composition and Harmful Material of Protaetia brevitarsis (흰점박이꽃무지(Protaetia brevitarsis)의 일반성분 및 유해물질 분석)

  • Chung, Mi Yeon;Gwon, Eun-Yeong;Hwang, Jae-Sam;Goo, Tae-Won;Yun, Eun-Young
    • Journal of Life Science
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    • v.23 no.5
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    • pp.664-668
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    • 2013
  • To evaluate Protaetia brevitarsis as a food material, we investigated its composition of nutritional and harmful components. Analysis of nutritional composition (moisture, crude protein, crude fat, crude ash, crude fiber, and carbohydrates) showed that the content of crude protein, fat, fiber, and ash were $57.86{\pm}0.01$%, $16.57{\pm}1.81$%, $5.31{\pm}0.10$%, and $8.36{\pm}0.10$% in Protaetia brevitarsis powder, respectively. Amino acids were composed of 17.68% essential and 33.97% non-essential in Protaetia brevitarsis powder. Protaetia brevitarsis powder contained 61.10% unsaturated fatty acid with oleic acids. Additionally, Protaetia brevitarsis powder had a large quantity of minerals related to body organization, such as K (1597 mg/100 g), P (724.1 mg/100 g), Mg (366.3 mg/100 g), and so on. We also confirmed that all bacteria and all heavy metals analyzed in this study, except for very small amount of Hg ($0.1{\pm}0.042$ mg/kg), were not detected in the lysophilized Protaetia brevitarsis powder.

The Effect of the Te on the Microstructure of Rapidly Solidification Ag-Sn-In Contact Material (급속응고한 Ag-Sn-In계 접점재료의 미세조직에 미치는 Te 의 영향)

  • Chang, Dae-Jung;Kwon, Gi-Bong;Kim, Young-Ju;Cho, Dae-Hyoung;Nam, Tae-Woon
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.20 no.1
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    • pp.86-91
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    • 2007
  • Contact material is widely used as electrical parts. Ag-CdO has a good wear resistance and stable contact resistance. But the disadvantages of Ag-Cd alloy are coarse Cd oxides and harmful metal, Cd. Then Ag-Sn alloy that has stable and fine Sn oxide at high temperature has been developed. In order to investigate the effect of Te additional that affects the formation of the oxide layer on the surface and the formation of oxide in matrix Ag, we studied the microstructures and properties of Ag-Sn-In(-Te) material fabricated by rapid solidification process. The experimental procedure were melting using high frequency induction, melt spinning, and internal oxidation. Specimens were examined and analyzed by Transmission electron microscopy(TEM), energy dispersive X-ray spectroscopy(EDS) and Vickers hardness. As a result, internal oxidation was completed even at $600^{\circ}C$. Te forms coarse $In_{2}TeO_{6}$ phase and makes fine and well dispersed $SnO_{2}$ Phase. 0.3 wt% Te shows favorable properties.