• Title/Summary/Keyword: Harmful material

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A Study on Improvement of Industrial Hood in Ventilation System for Elimination of Harmful Material and Dust (유해물질 및 공업용 분진 제거를 위한 산업용 후드 개선에 관한 연구)

  • Kim, Young-Sun;Oh, Yool-Kwon
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.20 no.4
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    • pp.238-244
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    • 2008
  • This study investigates on the improvement of inhalation effect of hood which attached new device named as "gas-guide-device" in local exhaust ventilation system for the effective elimination of harmful material and dust in manufacturing factory. The gas-guide-device having a diamond shape is composed of width (b) and two sides of a device (X, Y) and its size is selected the industrial hood under application in manufacturing factory after due consideration. In order to investigate the effect of gas-guide-device, numerical and experimental study is performed that the flow velocity is calculated and is measured by a commercial program "COMSOL $Multiphysics^{TM}$" and a hot wire type of anemometer, respectively. The numerical and experimental results are revealed is a similar pattern and flow velocity has improved to hood attached gas-guide-device. Also, the numerical method and result is also verified the dependance. Moreover, the optimum shape and size of gas-guide-device is revealed that the width (b) and the ratio of two sides of gas-guide-device (X, Y) has 125mm and 4 to 6.

Influence of Heat-treatment on Physical Properties of Nanocrystalline Indium Tin Oxide (ITO) Particle (나노급 인듐 주석 산화물 입자의 물성에 미치는 열처리의 영향)

  • 홍성제;한정인;정상권
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.17 no.7
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    • pp.747-753
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    • 2004
  • In this paper, nanocrystalline indium tin oxide (ITO) particles were fabricated by using synthesis without harmful elements. The synthetic method is to eliminate the chloridic and nitridic elements which are included in the current wet type synthetic method. Therefore, it is possible to lower synthetic temperature below 600 $^{\circ}C$ to eliminate the harmful elements. Accordingly, fine particle can be achieved by applying the process. Particle size, surface area, crystal structure, and composition ratio of the synthesized nanocrystalline ITO particle by using the method were analyzed with high resolution transmission electron microscopy (HRTEM), BET surface area analyzer, X-ray diffraction (XRD), and energy dispersion spectroscopy (EDS). As a result, its particle size is less than 10 nm, and the surface area exceeds 100 m$^2$/g. The XRD analysis indicates that the cystal structure of the powder is cubic one with orientation of <222>, <400>, <440>. Also, the analysis of the composition demonstrates that the around 8 wt% tin is uniformly included in In$_2$O$_3$ lattice of the nanoparticle.

The Effect of the Sn Amounts on the Microstructure of Rapidly Solidified Ag-Sn-In Alloys (급속응고한 Ag-Sn-In 미세조직에 미치는 Sn 함량 변화의 영향)

  • Cho, Dae-Hyoung;Kwon, Gi-Bong;Nam, Tae-Woon
    • Journal of Korea Foundry Society
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    • v.26 no.2
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    • pp.92-97
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    • 2006
  • Contact material is widely used as electrical parts. Ag-Cd alloy has a good wear resistance and stable contact resistance. But the disadvantages of Ag-Cd alloy are coarse Cd oxides and harmful metal, Cd. To solve the disadvantages of that, Ag-Sn alloy that has stable and fine Sn oxide at high temperature has been developed. In order to optimize Sn amount that affects the formation of the oxide layer on the surface, we worked for the microstructures and properties of Ag-Sn material fabricated by rapid solidification process. The experimental procedure were melting using high frequency induction, melt spinning, and internal oxidation. We have shown that the optimized Sn amount for high hardness is 7.09 wt%Sn. Surface oxide layer forms when Sn amount is over 9.45 wt%. The size of Sn oxide is 20 nm.

Reliability Assessment Methods for Electronic Component Removed Environmental Materials (환경물질을 제외한 전자부품의 신뢰성평가 방법 연구)

  • Lee, Jong-Boem;Cho, Jai-Rip
    • Proceedings of the Safety Management and Science Conference
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    • 2007.11a
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    • pp.275-298
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    • 2007
  • Recently, all kind of 21C-typed electronic goods show the tendency of hightechnology and digital convergence rapidly. Also, failure mechanism which differs from original goods concept presents. Today, failure mechanism which differs from one that was happened by restricted harmful environment material before adapted the raw of environment material is changing the paradigm of reliability engineering. Thus, when applied the environment matter of original and secondary material at the electronic goods were removed, reliability assessment method and prediction stay into low level. This study suggests as solution to overcome these phenomenon. The study on the management method of environmental restriction substances which is recognized as important element in the reliability assessment about environment material of electronic goods and the study on reliability assessment method of PWB without environment material are progressed.

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Reliability Assessment Methods for Electronic Component Removed Environmental Materials (환경물질을 제외한 전자부품의 신뢰성 평가 방법 연구)

  • Lee, Jong-Boem;Cho, Jai-Rip
    • Journal of the Korea Safety Management & Science
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    • v.9 no.6
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    • pp.55-68
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    • 2007
  • Recently, all kind of 21C-typed electronic goods show the tendency of hightechnology and digital convergence rapidly. Also, failure mechanism which differs from original goods concept presents. Today, failure mechanism which differs from one that was happened by restricted harmful environment material before adapted the raw of environment material is changing the paradigm of reliability engineering. Thus, when applied the environment matter of original and secondary material at the electronic goods were removed, reliability assessment method and prediction stay into low level. This study suggests as solution to overcome these phenomenon. The study on the management method of environmental restriction substances which is recognized as important element in the reliability assessment about environment material of electronic goods and the study on reliability assessment method of PWB without environment material are progressed.

Properties of Concrete Mixed with Waste Incinerated Bottom Ash (쓰레기 소각재를 혼입한 콘크리트의 재료특성 및 강도특성)

  • 어석홍;홍기호;최덕진;김희성
    • Proceedings of the Korea Concrete Institute Conference
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    • 2002.10a
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    • pp.217-222
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    • 2002
  • The purposes of this study are to investigate the material characteristics and strength properties of concrete mixed with waste incinerated bottom ash(BA), and to evaluate the leaching of environmentally harmful heavy metals from the bottom ash itself and from hardened concrete mixed with bottom ash. For this purpose, two reference mixes with W/C ratios of 0.45 and 0.55 were used, and the replacement proportion of BA was varied with the ratios of 0%, 30%, 50%, 70%, and 100% by volume of fine aggregate in the reference mixes. The variation of compressive and splitting tensile strength, workability and unit weight of concrete were considered. Test results showed that the strengths, workability and unit weight decreased with increase in proportion of BA replaced. Leaching test results showed that there would be no environmentally harmful problem from using BA as the substitutes of fine aggregates in concrete.

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An Experimental Study on the Compressive Strength of Cement Mortar mixing Anion Exchange Resin (음이온교환수지 혼입 시멘트 모르타르의 압축강도에 관한 실험적 연구)

  • Jeong, Do-Hyun;Lee, Yun-Su;Lee, Han-Seung
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2018.05a
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    • pp.54-55
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    • 2018
  • Reinforced concrete is a building material that is generally used in modern society. Securing the performance of reinforced concrete is directly connected to the durability and longevity of the building. One of the major factors that deteriorate the durability of concrete is harmful ion. Recently, the quality and improvement method of reinforced concrete for penetration of harmful ion has been studied. In this study, the bead type ion exchange resin is substituted for 0%, 3%, and 6% of the fine aggregate volume in the mortar. The speciments underwent underwater curing and were checked for compressive strengths of 3 days and 28 days. From the results of compressive strength, it can be seen that the higher the substitution ratio of the ion exchange resin, the lower the early strength and long-term strength development, especially the early strength development.

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A study of decomposition of harmful gases using Composite catalyst by Photocatalytic plasma reactions (복합촉매를 이용한 플라즈마 반응에 의한 유해가스의 제거에 관한 연구)

  • Kim, Gwan-Jung;U, In-Seong;Park, Hwa-Yong;Lee, Hong-Ju
    • Proceedings of the Safety Management and Science Conference
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    • 2012.04a
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    • pp.421-433
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    • 2012
  • The objective of this study is to obtain the optimal process condition and the maximum decomposition efficiency by measuring the decomposition efficiency, electricity consumption, and voltage in accordance with the change of the process variables such as the frequency, maintaining time period, concentration, electrode material, thickness of the electrode, the number of windings of the electrode, and added materials etc. of the harmful atmospheric contamination gases such as NO, $NO_2$, and $SO_2$etc. with the plasma which is generated by the discharging of the specially designed and manufactured $TiO_2$ catalysis reactor and SPCP reactor.

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Rapid Management Mechanism Against Harmful Materials of Agri-Food Based on Big Data Analysis (빅 데이터 분석 기반 농 식품 위해인자 신속관리 방법)

  • Park, Hyeon;Kang, Sung-soo;Jeong, Hoon;Kim, Se-Han
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.40 no.6
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    • pp.1166-1174
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    • 2015
  • There were the attempts to prevent the spread of harmful materials of the agri-food through the record tracking of the products with the bar code, the partial information tracking of the agri-food storage and the delivery vehicle, or the control of the temperature by intuition. However, there were many problems in the attempts because of the insufficient information, the information distortion and the independent information network of each distribution company. As a result, it is difficult to prevent the spread over the life-cycle of the agri-food using the attempts. To solve the problems, we propose the mechanism mainly to do context awareness, predict, and track the harmful materials of agri-food using big data processing.

An Experimental Study on the Resistance to Penetration of Harmful Ions in Surface Coatings Material Containing Organic Corrosion inhibitor (유기계 방청제를 혼입한 표면피복재의 유해이온 침투저항에 관한 실험적 연구)

  • Ryu, Hwa-Sung;Shin, Sang-Heon;Lee, Han-Seung
    • Journal of the Korea Institute of Building Construction
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    • v.17 no.2
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    • pp.157-166
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    • 2017
  • In general, carbonation and chlorine ions are the most harmful causes of deterioration of concrete structures. Recently, a method has been developed to control the corrosion of rebar in concrete containing chloride by impregnating a Surface coating material with a inhibitor. In this study, accelerated carbonation and differential thermogravimetric analysis (TG-DTA) and CASS tests were carried out to evaluate the characteristics of Surface coatings containing Organic Corrosion inhibitors which are excellent in corrosion inhibition and fix degradation causes $CO_2$ and $Cl^-$. As a result of the experiment, TG-DTA analysis and accelerated carbonation showed that $CO_2$ was directly reacted with amine derivative in concrete by the incorporation of Organic Corrosion inhibitor. In other words, $CO_2$ was immobilized and carbonation inhibition effect was confirmed. In addition, in the CASS test, the specimen coated with the Surface coating material containing the Organic Corrosion inhibitor with $Cl^-$ fixing property showed no corrosion until the 28th day and had excellent performance in preventing corrosion of a rebar by the chloride ion.