• Title/Summary/Keyword: HCN

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Study of the Density of Smoke and Harmful Gases of Adhesive Indirect Moxibustion (접착식 간접구의 연기 밀도 및 유해가스 발생 확인 연구)

  • Kim, Eun-Jung;Kim, Yu-Jong;Hwang, Ji-Hoo;Cho, Hyun-Seok;Kim, Kyung-Ho;Lee, Seung-Deok;Kim, Kap-Sung
    • The Journal of Korean Medicine
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    • v.33 no.1
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    • pp.42-51
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    • 2012
  • Objectives: We measured the density of smoke and harmful gases emitted from burning adhesive indirect moxa. Through the test we aimed to find out if there was an excessive amount of smoke emitted and if it included harmful gases. Methods: 9 types of adhesive indirect moxa were chosen. The buffer layers which do not burn during treatment were removed and 10g of each moxa were made into powder and put into a holder. A smoke density chamber (Smoke Density Chamber FTT. U.K) and Fourier transform infrared spectroscopy (FT-IR I 4001. MIDAC U.S.A.) were used to measure the density of smoke and harmful gases emitted from burning moxa by ISO 5659-2 test. Results: The result of measuring maximum smoke density showed that the regular indirect adhesive moxa (A-F) emitted high density smoke of 172.1-291.4Ds. The smokeless moxas, Seoam moxas, emitted the least amount of 3.4-5.5Ds. Concentrations of 7 typical harmful gases (CO, HCl, HCN, HBr, HF, SO2, NOx) were measured and all of the moxas emitted CO due to incomplete combustion. 4 types of moxa emitted NOx and all smokless moxas emitted NOx. HBr, HCN, HCl, HF, SO2 were not found in any of the moxas. Conclusions: The amount of harmful gases emitted from burning moxa was much lower than short-term exposure standards of chemical and physical factors (Ministry of Labor 2010-44). Further experiments measuring gases from moxa combustion should be done in larger environments similar to normal medical clinics.

Experimental Study on the Effects of Combustion Products on the Human Body and Suggestion of Law Revision (흡음재의 연소 생성물이 인체에 미치는 영향에 대한 실험적 연구 및 법률 개정 제언)

  • Kang, Jung Ki;Choi, Don Mook
    • Fire Science and Engineering
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    • v.33 no.4
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    • pp.28-34
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    • 2019
  • Regardless of the ignition source, the main factors affecting the spread of flames to the human body are combustibles. The sound absorption material, which is the finishing material used in music institutes and karaoke rooms, consists of polyurethane that generates a large amount of toxic gas with a high amount of combustion gases during a fire. Still, the current law does not require the use of impregnated finishing materials for tutoring services with less than 100 users. In this study, the rate of flame diffusion was measured using the MultiRaelite composite gas measuring instrument (target substance VOC, HCHO, SO2, CO2, CO, HCN, and NO2) for the collection of sound-absorbing materials installed in the actual music academy. The results showed that the toxic gas found in this experiment exceeded the allowable concentration of TWA (Time Weighted Average) and STEL (Short Term Exposure Limit). In addition, a comparative combustion test of the general sound absorber and non-combustion sound absorbing materials on the market showed wide differences in ignition and diffusion. Therefore, based on the results of the experiment, private institutes with less than 100 users should be mandated to use non-combustion sound absorbing materials.

Catalytic Wet Gasification of Biomass Mixed Fuels (바이오메스 혼합연료의 습윤 촉매 가스화 연구)

  • Kang, Sung-Kyu;Lee, Seung-Jae;Ryu, In-Soo;Hur, Sung
    • Journal of the Korea Organic Resources Recycling Association
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    • v.17 no.2
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    • pp.59-72
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    • 2009
  • In order to utilize sewage sludge as a heat source of energy, it goes without saying that the fuel should be clean and pose no threat to the environment. As a consequent, it should not contain even minute quantities of heavy metals / impurities. The SOCA (Sludge-Oil-Coal- Agglomerates) fuel can meet all these requirements. SOCA being a solid fuel can be gasified for the production of clean energy. Wet catalytic gasification is the most appropriate process for SOCA containing nearly 60% water. It is important to note that the SOCA thus obtained inherits ca. 40~50% of sulfur from the coal used. It can poison the catalyst during catalytic gasification process. Consequently, it becomes important to choose a proper catalyst for the gasification. Calcium was found to be ideal choice as a catalyst for the gasification of SOCA. The optimal gasification was performed at $850^{\circ}C$ with water vapor. The role of fuel-N is of utmost importance in the gasification of SOCA. The gasification should be controlled to reduce the production of HCN to a minimum and enhance its conversion to $N_2$ and/or $NH_3$.

The Effect of Some Additives on the Components of Cigarette Smoke (첨가제가 담배 연기성분에 미치는 영향)

  • Ra Do-Young;J도 Byong-Kwon;Lee Chang-Kook;Cho Si-Hyung;Lee Dong-Wook
    • Journal of the Korean Society of Tobacco Science
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    • v.27 no.1 s.53
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    • pp.40-50
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    • 2005
  • The influence of tobacco additives on the composition of the combustion products in mainstream smoke is discussed. The effect of additives on the chemical composition of smoke have been further evaluated in order to discover additives that would alter the chemical composition of smoke. Tobacco was uniformly treated at a 1-5$\%$ level with 8 classes of additives. Group M treated with alkali metal salt and group S, F, O give lower tar, nicotine and CO values than the control. Group AN treated with natural antioxidant gives higher tar and CO values than the control. The increases are most probably due to the high transfer rate of the ingredients to smoke. M3 and P1 reduced above the $50\%$ of TSNA from the smoke. M4 and P1 reduced above the $50\%$ of HCN from the smoke. These results suggest that tobacco additives alter pyrolysis or combustion product distribution and provide fundamental data to lead the development of a RRP(reduced risk product).

A Study on Toxicity Evaluation of Combustion Gases Released from the Residental Container Fire - Efficiency Test for the Fire Gas Mask Filters (주거용 컨테이너 화재시 발생되는 연소가스의 독성 평가에 관한 연구 - 화재용 방독면 filter의 성능평가를 중심으로)

  • Lee Jung Yun;Kim Jeong Hun;Kim Youn-Hi;Jung Ki Chang
    • Journal of the Korean Society of Safety
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    • v.19 no.4 s.68
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    • pp.48-54
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    • 2004
  • The recent Ire incident in an elementary school of Chonan city causes the media focus on the fire safety of residential container buildings. In this study, real fire tests were conducted in this kind of buildings. Combustion products including $O_2,\; CO_2,\;CO,\;NOx,\;SOx,\;HCI,\;HCN$ were measured, and blood samples of lab rats were analyzed in terms of Co-Hb, Glucose, AST(GOT), ALT(GPT), in order to investigate the hazard-reduction effects of employing gas mask protected with filter during the fire emergency of residential container buildings. According to the test results, whether or not employing the filter showed a sheer difference in the toxicity of the fire-induced gases, and then the importance of wearing a gas mask was evidently demonstrated.

The Effect of Meridian Acupressure on Constipation in the Bed-ridden Aged with Stroke (경혈지압이 뇌졸중 와상노인 환자의 변비완화에 미치는 효과)

  • Jung, Young-Hoe;Jun, Jum-Yi
    • Korean Journal of Adult Nursing
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    • v.20 no.4
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    • pp.664-673
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    • 2008
  • Purpose: The purpose of this study was to identify the effect of meridian acupressure on constipation in bed-ridden aged inpatients. Methods: The research design was a non-synchronized non-equivalent control group pretest-posttest design. The subjects consisted of 28 bed-ridden aged inpatients. Meridian acupressure was administered to the experimental group at 30 minutes before breakfast every morning for two weeks. Each meridian was pressured for 10 seconds, 10 times. The frequency of defecation and stool form were examined every day. The data was analyzed by the $x^2$-test, Fisher's exact test, t-test and repeated measures ANOVA. Results: The experimental group given Meridian Acupressure had a higher frequency of defecation(F = 59.372, p = .000) and normal stool(F = 46.046, p = .000) than the control group. Conclusion: The results suggest that Meridian Acupressure was an effective method for the relief of constipation for bed-ridden aged inpatients. A follow -up research is needed to validate that other patients with constipation can use the Meridian Acupressure as a non-invasive nursing intervention instead of a laxative or enema.

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MOLECULAR CORES OF THE HIGH-LATITUDE CLOUD MBM7

  • MINH Y. C.;KIM H. G.;KIM S. J.;BERGMAN P.;JOHANSSON L. E. B.
    • Journal of The Korean Astronomical Society
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    • v.33 no.1
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    • pp.37-45
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    • 2000
  • We have investigated the properties of the high-latitude cloud MBM 7 using the 3 mm transitions of CO, CS, HCN, $HCO^+,\;C_3H_2,\;N_2H^+$, and SiO. The molecular component of MBM 7 shows a very clumpy structure with a size of $\le$0.5 pc, elongated along the northwest-southeast direction, perpendicularly to an extended HI component, which could be resulted from shock formation. We have derived physical properties for two molecular cores in the central region. Their sizes are 0.1-0.3 pc and masses 1-2 M$\bigodot$ having an average volume density $\~2{\times}10^3 cm^{-3}$ at the peak of molecular emission. We have tested the stability of the cores using the full version of the virial theorem and found that the cores are stabilized with ambient medium, and they are expected not to be dissipated easily without external perturbations. Therefore MBM 7 does not seem to be a site for new star formation. The molecular abundances in the densest core appear to be much less (by about one order of magnitude) than the 'general' dark cloud values. If the depletions of heavy elements are not significant in the HLCs compared with those in typical dark clouds, our results may suggest different chemical evolutionary stages or different chemical environments of the HLCs compared with dense dark clouds in the Galactic plane.

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Roles of Key Elementary Reaction for NO Formation in Premixed Flame and Counterflow Diffusion Flame (예혼합 및 대향류확산 화염에서 NO의 생성에 미치는 소반응의 역할)

  • ;;H.S.Yamashita
    • Journal of Advanced Marine Engineering and Technology
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    • v.22 no.1
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    • pp.108-116
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    • 1998
  • In this paper it is investigated the roles of key elementary reactions for NO formation in methane-air one-dimensional premixed flame and counterflow diffusion flame, which were studied numerically by using NO kinetics and $C_{2}$ -chemistry complied by Miller and Bowman. The spatial distributions of the reaction rates of 9 main elementary reactions directly related to NO formation and destruction were calculated. Integration of the rates of all reactions in the NO formation across the flame yields the quantitative reaction path diagram, which shows clearly relative importance of each reaction path in NO formation and how it changes with the type and parameters of the flame. The results show that the thermal and Fenimore mechanisms are dominant respectively for learn and rich premixed flames, and the latter is dominant for diffusion flames. In addition, it was found that the HCN recycle route is important for diffusion flame, and that the routes of mutual transformation between NO and NO$^{2}$, and between NO and HNO do not contribute to the net NO formation.

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MOLECULAR LINE STUDY OF L1014 WITH SRAO 6M TELESCOPE (L1014 분자운 핵에 대한 SRAO 6m 망원경을 이용한 분자선 관측연구)

  • Lee, Chang-Won
    • Publications of The Korean Astronomical Society
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    • v.20 no.1 s.24
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    • pp.1-5
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    • 2005
  • We report molecular line observations of CO(1-0), $^{13}CO(1-0)$, CS(2-1), and HCN(1-0) with SRAO 6m telescope toward L1014-IRS which is thought to be a very faint infrared source embedded in previously known 'starless' core L1014. The CO(1-0) observations find several components with different velocities along the line of sight of L1014, $4km\;s^{-1}$ and between $40{\sim}50km\;s^{-1}$. We find a parsec scale CO molecular outflow at the $4km\;s^{-1}$ component for the first time the direction of which is coincident with that of the small scale (${\sim}500pc$) outflow previously found. Although the observation is not covered for whole area of the outflow, the size of the molecular outflow seems not very inconsistent with the expected age of L1014-IRS. More accurate size and shape of the molecular outflow from L1014-IRS will be determined from the full coverage mapping in CO over the outflow region in very near future.

On the Chemical Evolution of Collapsing Starless Cores

  • Seo, Young-Min;Lee, Jeong-Eun;Kim, Jong-Soo;Hong, Seung-Soo
    • The Bulletin of The Korean Astronomical Society
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    • v.35 no.2
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    • pp.73.2-73.2
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    • 2010
  • In order to understand internal dynamics of starless cores, molecular line emissions are usually observed. From profiles of the molecular lines, internal motions of starless cores have been deduced using a simple radiative transfer model such as the two-layer model (Myers et al.1996). This brings complexities arising from the chemical evolution. The motivation of this study is to follow the chemical evolution of a starless core that goes through gravitational contraction. For this purpose, we have performed hydrodynamical simulations with a marginally unstable Bonnor-Ebert sphere as an initial condition. We follow the chemical evolution of this core with changing conditions such as the chemical reaction rate at the dust surface and the strength of radiation field that penetrate into the core. At the core center, the molecules suffer from a higher degree of molecular depletion on the dust covered by ice rather than on the bare silicate dust. The stronger radiation field dissociates more molecules at the core envelope. From analysis on the line profile using the two-layer model, we found that the speed of inward motion deduced from the HCN F = 2-1 line adequately traces the true infall speed, when the dust is covered by ice and the core is exposed to the diffuse interstellar radiation field. Under different conditions, the two-layer model significantly underestimate the infall speed.

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