• Title/Summary/Keyword: hazardous gas

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Study on Self-extinguishing Epoxy Resin Composition (자기소화성 에폭시 수지 조성물 연구)

  • Kim, Young Chul;Cha, Ok Ja;Kim, Kyung Man
    • Journal of Adhesion and Interface
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    • v.11 no.4
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    • pp.168-173
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    • 2010
  • Flame retardant halogen containing compounds have been replaced as environmentally safe material which does not contain hazardous materials generating toxic gas. Self-extinguishing epoxy resin compositions have been studied in order to produce eco-friendly epoxy molding compound, which is used as insulating materials in semiconductor. We developed self-extinguishing epoxy resin compositions which do not contain halogen compounds with new epoxy resin (E3). The new epoxy molding compound (EMC-1) showed high flame resistance (UL-V0) and high thermal resistance ($451.9^{\circ}C$ at 5 wt% loss) enough to use as eco-friendly material.

A Study on the Development of Simulator for LPG Transporting System (LPG 이송시스템 교육장비(시뮬레이터) 개발에 관한 연구)

  • Leem, Sa-Hwan;Huh, Yong-Jeong
    • The Journal of Korean Institute for Practical Engineering Education
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    • v.1 no.1
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    • pp.66-71
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    • 2009
  • Simulator is being utilized usefully in industrial education. Especially, it is the best method to use for the higher value-added business or hazardous system to train. Also, it is needed to effect in forward-looking industrial education changing from theoretical education to hands-on training. Therefore, the development of equipment that can be used in both theory and experience class and its application to education help you to maximize the training effect on LPG transportation method when you work in the field. As a result of its applying to the education, the understanding of transportation system of educational equipment came out 4.86 points of 5 points, the utilization on site had 4.47 points/5 points, and the satisfaction has 0.5 points/4.48 points. The LPG transporting system(simulator) is considered effective when it is utilized in the education.

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Analysis of Heavy Metal Concentration on Working Clothes for Waste Incinerating Workers (생활폐기물 소각장 작업복의 중금속 분석)

  • Park, Soon-Ja
    • The Korean Journal of Community Living Science
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    • v.18 no.1
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    • pp.39-53
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    • 2007
  • The purpose of this study was to determine the characteristics of an experimental protective clothing material with regard to comfort and isolation from the hazardous heavy metals produced in municipal waste incineration. An analysis was conducted on the total concentrations of heavy metals in some parts such as surface, middle layer, and interior for the treated fabric, and the untreated one, and working clothes. We conclude that the processed fabric with charcoal for working clothes showed the least exposure to heavy metals of the three. Working clothes worn by workers during waste incineration were much more contaminated than the untreated and treated materials. The material of working clothes could be chosen according to the function with regard to its original chemical characteristics, which are the proper results of the dyeing process. The processed fabric material has high degrees of moisture regain, thermal insulation, water vapor penetration, and antibacterial function; consequently, it is much more comfortable to wear. The fabric material proposed in this research contributed much more to blocking heavy metal concentrations (such as Cd, Pb, Cu, Cr, Zn, Mn) than did the fabric of working clothes at present. Consequently, we strongly suggest that the material of working clothes be upgraded by adopting the above-mentioned charcoal-processed fabric. Materials of working clothes must be improved to increase comfort and prevent harmful gas, flying dust, and heavy metals from permeating the fabrics.

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Emission Characteristics and Hazard Assessment of Polycyclic Aromatic Hydrocarbon (PAHs) from Solid Fuel Facilities (고형연료제품 사용시설에 따른 다환방향족탄화수소 (PAHs)의 배출특성 및 유해성 평가)

  • Heo, Sun-Hwa;Lim, Seung-Young;Kang, Dae-Il;Kim, Dae-Gon;Jeon, Ki-Joon;Jang, Kee-Won
    • Journal of Korean Society for Atmospheric Environment
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    • v.33 no.4
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    • pp.333-341
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    • 2017
  • Recently, the earth has shown the limit of environmental capacity. It is also experiencing an environmental crisis with rising energy prices and depletion of coal. Therefore, development of renewable energy is very important solution. However, waste fuel solid are renewable fuels, but they cause environmental problems. In this study, the emission characteristics of hazardous air pollutants were analyzed through measurements at the facilities using solid fuels (SRF, BIO-SRF). Analysis method of PAHs are based on the Korea Standard Methods for Examination. The analysis of PAHs showed that the concentration much higher in Naphthalene, and Benzo(a)pyrene showed at a higher concentration incertain sources. As a result of gas phase and particle phase PAHs, most of Benzo(a)pyrene appeared to be particulate. Through the results of this study will provide basic data for atmospheric environmental management.

Residues of Dioxins in Soil Cultured Ginseng of North Gyeongbuk (경북북부 인삼 재배 토양 중 Dioxins의 잔류)

  • Kim, Jung-Ho
    • Journal of Environmental Science International
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    • v.21 no.4
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    • pp.451-459
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    • 2012
  • PCDDs(Polychlorinated dibenzo-$p$-dioxins) and PCDFs(polychlorinated dibenzofurans) are measured in soil of Yeungju and Sangju on North Gyeongbuk to investigate the risk assessment of dioxins. Dioxins are analyzed by HRGC/HRMS(high resolution gas chromatography - high resolution mass spectrometer). 2,3,7,8-T4CDD and 1,2,3,7,8-Pe5CDD in soil on Yeungju and Sangju are not detected. Also, 2,3,7,8-T4CDF is not detected in soil on Yeungju and Sangju. PCDDs and PCDFs in Yeungju soil are 1.957 pg/g and 0.294 pg/g, respectively. Total of dioxins in Yeungju soil are 2.251 pg/g. PCDDs and PCDFs in Sangju soil are 1.220 pg/g and 0.420 pg/g, respectively. Total of dioxins in Sangju soil are 1.640 pg/g. PCDDs and PCDFs in Yeungju soil are 0.0049 pg WHO-TEQ/g and 0.0123 pg WHO-TEQ/g, respectively. Total of dioxins with PCDDs and PCDFs in Yeungju soil are 0.0172 pg WHO-TEQ/g. PCDDs and PCDFs in Sangju soil are 0.0065 pg WHO-TEQ/g and 0.0213 pg WHO-TEQ/g, respectively. Total of dioxins with PCDDs and PCDFs in Sangju soil are 0.0278 pg WHO-TEQ/g. Amount for pg/g concentration unit of PCDDs is higher than amount of PCDFs in soil. But, WHO-TEQ of PCDFs is higher than WHO-TEQ of PCDDs in soil.

A Study of Local Ventilation Design on PC Programm (국소환기 설계의 전산화에 관한 연구)

  • Yoon, Myong Cho
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.3 no.2
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    • pp.213-226
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    • 1993
  • The purpose of this study is to computerize the design of single source for a duct work system which is essential for the improvement of working places. There are different types of hood, such as general hood, push pull hood and canopy hood. And out of these three types, general hood and canopy hood were used as subjects of this study. The software used here was Quattro Pro 123 programm, and the hardware was IBM PS/SX(type 5510-SK4 S/N 83-05164). And the results are tabulated in

    and
    . All of the hazardous factors of working places, except for physical factors, such as noise, vibration, illumination and etc, are control measurement related. In order words, workiong places that have problems with toxic gas, mist, fume, dust, odors, biological factors or wetness can be improved by means of the local ventilation design. However, the reqires very complicate processes, and in the case of canopy hood, particularly, one runs into difficulties due to frequent discrepancies generated from calculations through many processes. Recently, progress of the computer hardware technics has been dazzling, and also the software is development rapidly. As proven in the results of this study, it is good that designs for industrial ventilation systems are readily available for easy use. It is hopeful that young scholars will develop easier and quicker methods for local ventilation designs in the future.

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  • Pyrolysis Reaction for the Treatment of Hazardous Halogenated Hydrocarbon Waste (유해 할로겐화 탄화수소 폐기물 처리를 위한 열분해 반응)

    • 조완근
      • Journal of Environmental Science International
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      • v.6 no.4
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      • pp.399-407
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      • 1997
    • The pyrolysis reactions of atomic hydrogen with chloroform were studied In a 4 cm 1.6. tubular flow reactor with low flow velocity 1518 cm/sec and a 2.6 cm 1.4. tubular flow reactor with high flow velocity (1227 cm/sec). The hydrogen atom concentration was measured by chemiluminescence titration with nitrogen dioxide, and the chloroform concentrations were determined using a gas chromatography. The chloroform conversion efficiency depended on both the chloroform flow rate and linear flow velocity, but 416 not depend on the flow rate of hydrogen atom. A computer model was employed to estimate a rate constant for the initial reaction of atomic hydrogen with chloroform. The model consisted of a scheme for chloroform-hydrogen atom reaction, Runge-Kutta 4th-order method for Integration of first-order differential equations describing the time dependence of the concentrations of various chemical species, and Rosenbrock method for optimization to match model and experimental results. The scheme for chloroform-hydrogen atom reaction Included 22 elementary reactions. The rate constant estimated using the data obtained from the 2.6 cm 1.4. reactor was to be 8.1 $\times$ $10^{-14}$ $cm^3$/molecule-sec and 3.8 $\times$ $10^{-15}$ cms/molecule-sec, and the deviations of computer model from experimental results were 9% and 12% , for the each reaction time of 0.028 sec and 0.072 sec, respectively.

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    Compatibility of Diazepam with Polypropylene Multilayer Infusion Container

    • Noh, Dong-Il;Park, Kyu-Nam;Chun, Heung-Jae;Park, Chong-Won;Jang, Ju-Woong;Ahn, Yun-Gyong
      • Macromolecular Research
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      • v.17 no.7
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      • pp.516-521
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      • 2009
    • Techflex$^{(R)}$, a polypropylene-lined, multilayer infusion bag, was studied for its compatibility with diazepam, in comparison to the conventional infusion bag, Safeflex$^{(R)}$, which is comprised of poly(vinyl chloride) (PVC). Diazepam was diluted in 0.9% sodium chloride isotonic solution and stored in the infusion bags for 24 h. To evaluate the sorption of diazepam into the infusion bags during storage, the concentration of the drug remaining in the bag was measured using gas chromatography-mass spectroscopy. The PVC bags exhibited a marked sorption of diazepam, with a drug loss reaching up to 90% of the initial concentration after 24 h of contact, whereas Techflex$^{(R)}$ inhibited the drug sorption, showing approximately 10%, under the same conditions. The differences in the sorption behaviors of the bags are discussed in terms of solubility parameters and crystallinities of the polymers.

    Formation of Polybrominated Dibenzo-p-dioxins/Furans (PBDDs/Fs) by the Pyrolysis of 2,4-Dibromophenol, 2,6-Dibromophenol, and 2,4,6-Tribromophenol

    • Na, Yun-Cheol;Hong, Jong-Ki;Kim, Kang-Jin
      • Bulletin of the Korean Chemical Society
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      • v.28 no.4
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      • pp.547-552
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      • 2007
    • This study examined the thermal reactions of 2,4-dibromophenol (diBP), 2,6-diBP and 2,4,6-triBP. The products obtained under pyrolytic conditions were analyzed by gas chromatography/mass spectrometry (GC/MS). 2,7-dibromodibenzo-p-dioxin (diBDD) was the major compound produced from the thermal reaction of 2,4-diBP. In addition, monoBDD and triBDDs were obtained through a process of debromination and bromination, respectively. The pyrolysis of 2,6-diBP and 2,4,6-triBP produced two major brominated dioxin isomers through direct condensation and a Smiles rearrangement. The two ortho-Brs in 2,6-diBP and 2,4,6-triBP mainly led to the production of dioxins, whereas in addition to 2,7-diBDD, 2,4-diBP produced two furans as minor products, 2,8-dibromodibenzofuran (diBDF) and 2,4,8-triBDF, through the intermediate dihydroxybiphenyl (DOHB). The maximum yield of the major dioxins was obtained at 400 oC, and decomposition by debromination at 500 oC resulted in less substituted bromodioxins.

    The Effects of Welding Process Parameters on Weld bead Width in GMAW Processes (GMAW 공정 중 용접 변수들이 용접 폭에 미치는 영향에 관한 연구)

    • 김일수;권욱현;박창언
      • Journal of Welding and Joining
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      • v.14 no.4
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      • pp.33-42
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      • 1996
    • In recent years there has been a significant growth in the use of the automated and/or robotic welding system, carried out as a means of improving productivity and quality, reducing product costs and removing the operator from tedious and potentially hazardous environments. One of the major difficulties with the automated and/or robotic welding process is the inherent lack of mathematical models for determination of suitable welding process parameters. Partial-penetration, single-pass bead-on-plate welds were fabricated in 12mm AS 1204 mild steel flats employing five different welding process parameters. The experimental results were used to develop three empirical equations: curvilinear; polynomial; and linear equations. The results were also employed to find the best mathematical equation under weld bend width to assist in the process control algorithms for the Gas Metal Arc Welding(GMAW) process and to correlate welding process parameters with weld bead width of bead-on-plates deposited. With the help of a standard statistical package program. SAS, multipe regression analysis was undertaken for investigating and modeling the GMAW process, and significance test techniques were applied for the interpretation of the experimental data.

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