• Title/Summary/Keyword: Toxic Gas

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The Analysis on Work Clothes' Clothing Comfort and Wearer Mobility of Welding and Grinding Workers in the Machine and Shipbuilding Industries (기계, 조선산업 용접 및 사상공정 근로자의 작업복 착의실태와 착용감 및 동작성능 연구)

  • Park, Gin-Ah;Park, Hye-Won;Bae, Hyun-Sook;Kim, Jie-Kwan
    • Journal of Fashion Business
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    • v.15 no.2
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    • pp.145-159
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    • 2011
  • The study aimed to analyze the status quo of manufacturing work environment and the work clothes' clothing comfort and wearer mobility of welding and grinding work processes in the machine and shipbuilding industries in South Korea. A questionnaire survey was conducted for the study, which consisted of questions about work clothes' clothing comfort and wearer mobility according to body parts. The findings derived from the research were: the high impact levels of work environment factors on welding and grinding work processes were noise, metal fragment, superheat, toxic gas, UV ray factors. Subject workers' assessment of work clothes' clothing pressures were in the levels between 3 (i.e. moderate) and 4 (i.e. comfortable) in a range of 5-point scale. The impact levels of wearer mobility factor were high on the work processes of welding and grinding in machine and grinding in shipbuilding. While welding process in shipbuilding showed a 'moderate' wearer mobility level and this was because its work postures were uncomfortable yet the rate of the motion change was low. The consideration to develop the work clothes specialized for certain work processes should include the materials' protecting performance from the hazardous work environment factors; and work clothes' designs that provides workers with maximized clothing comfort and wearer mobility for bending or tilting postures of upper, lower and lateral body parts defined in the study.

Evaluation of the Appropriateness of Smoke Control Conditions of Platform at the Subway Fire by using FDS (FDS를 이용한 지하철 객실 화재 시 승강장 제연조건의 적정성 평가)

  • Kim, Ki-Sung;Song, Dong-Woo;Lee, Su-Kyung
    • Fire Science and Engineering
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    • v.27 no.5
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    • pp.8-14
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    • 2013
  • In the subway, various fires continue to take place across the world. In the Daegu subway accident in 2003, many people were damaged by shortened visibility range caused by toxic gas and smoke. This paper, assuming that a subway fire happens in the Mandeok Station of the subway system in Busan, analyzed different smoke-spreading situations depending on the ventilation situation at its platform (opening of the train doors, operation of ventilation facilities in the tunnel, and working of fire door), using FDS. The calculation proved that it would be more effective to secure evacuation route when the ventilation facilities of the tunnel are not operated, than when they are on. And, it was also found that the case where the doors of the platform to the escape route and only the platform-facing doors of the subway car on fire office are open would be more effective to ventilation than the case where all the doors are open. And, it was found to be important that the fire doors of the platform are working properly.

Fire Patterns According to the Blood Hb-CO Concentration of Charred Bodies (소사체의 혈중 헤모글로빈-일산화탄소 농도에 따른 연소형태 연구)

  • Choi, Seung-Bok;Oh, Bu-Yeol;Choi, Don-Mook
    • Fire Science and Engineering
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    • v.26 no.3
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    • pp.40-48
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    • 2012
  • Fire patterns have been used to determine the origin and cause of fires in every setting imaginable. However, it is very difficult to identify fire patterns and causes from the fire-damaged remains of a devastated structure. If someone was killed by the fire, it is possible to identify fire patterns by analyzing the Hb-CO concentration in charred bodies of deceased as well as the pace of the fire. For example, a low level of Hb-CO concentration in the charred bodies indicate a rapid fire with accelerants and the death was caused by severe heat and thick toxic fumes. However, a high level of Hb-CO concentration in the charred bodies demonstrates that the fire was slow and/or there was a flameless form of combustion. Thus, it is possible to identify fire patterns through analyzing the level of Hb-CO concentration on the dead from the fire. In this study, the Hb-CO concentration in the charred bodies was from 3 % at the case of gas burning oneself to death to 93 % at the death caused by smoldering fire.

Carbon Monoxide Ameliorates 6-Hydroxydopamine-Induced Cell Death in C6 Glioma Cells

  • Moon, Hyewon;Jang, Jung-Hee;Jang, Tae Chang;Park, Gyu Hwan
    • Biomolecules & Therapeutics
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    • v.26 no.2
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    • pp.175-181
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    • 2018
  • Carbon monoxide (CO) is well-known as toxic gas and intrinsic signaling molecule such as neurotransmitter and blood vessel relaxant. Recently, it has been reported that low concentration of CO exerts therapeutic actions under various pathological conditions including liver failure, heart failure, gastric cancer, and cardiac arrest. However, little has been known about the effect of CO in neurodegenerative diseases like Parkinson's disease (PD). To test whether CO could exert a beneficial action during oxidative cell death in PD, we examined the effects of CO on 6-hydroxydopamine (6-OHDA)-induced cell death in C6 glioma cells. Treatment of CO-releasing molecule-2 (CORM-2) significantly attenuated 6-OHDA-induced apoptotic cell death in a dose-dependent manner. CORM-2 treatment decreased Bax/Bcl2 ratio and caspase-3 activity, which had been increased by 6-OHDA. CORM-2 increased phosphorylation of NF-E2-related factor 2 (Nrf2) which is a transcription factor regulating antioxidant proteins. Subsequently, CORM-2 also increased the expression of heme oxygenase-1 and superoxide dismutases (CuZnSOD and MnSOD), which were antioxidant enzymes regulated by Nrf2. These results suggest that CO released by CORM-2 treatment may have protective effects against oxidative cell death in PD through the potentiation of cellular adaptive survival responses via activation of Nrf2 and upregulation of heme oxygenase-1, leading to increasing antioxidant defense capacity.

Characterization of a lipopolysaccharide-protein complex of type A Pasteurella multocida (Pasteurella multocida type A의 lipopolysaccharide-protein 복합체의 특성)

  • Ryu, Hyo-ik;Kim, Chul-joong
    • Korean Journal of Veterinary Research
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    • v.40 no.1
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    • pp.63-71
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    • 2000
  • An immunogenic, high molecular weight lipopolysaccharide (LPS)-protein complex isolated from a potassium thioncyanate extract of a Pasteurella multocida (P multocida ; strain P-2383, capsular type A and somatic type 3) was characterized. Chemical analysis of the complex by gas chromatography on a capillary column demonstrated that this complex contained most of the chemical constituents characteristic of LPS extracted by the phenol-water methed from the whole bacterium. However, there was proportionately more carbohydrate than fatty acid in the complex in contrast to LPS in which fatty acid seemed to be in excess. When toxicity of the complex was evaluated in 10-day-old chicken embryos, the complex was less toxic ($LD_{50}=12.72{\mu}g$) than the purified LPS ($LD_{50}=0.44{\mu}g$). The $LD_{50}$, of the LPS moiety extracted from the complex was $5.24{\mu}g$. Composition of the complex was analyzed by SDS-PAGE with silver staining and Western immunoblotting. The complex did not migrate through the polyacrylamide gel unless dissociated with SDS. The complex dissociated with SDS contained at least 32 different protein and polysaccharide components: 18 components reacted with an antiserum against the complex. There was no significant compositional variation between the complexes from different strains, but quantitative differences in individual components were noted. When cross-protectivity of the complex was evaluated in mice, this complex provided substantial protection not only against the homologous bacteriun but also against different P multocida strains of the same serotype. LPS-protein complexes isolated by the same method from other strains also induced protection against an challenge with P-2383.

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Aerosol Jet Deposition of $CuInS_2$ Thin Films

  • Fan, Rong;Kong, Seon-Mi;Kim, Dong-Chan;Chung, Chee-Won
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.02a
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    • pp.159-159
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    • 2011
  • Among the semiconductor ternary compounds in the I-III-$VI_2$ series, $CulnS_2$ ($CulnSe_2$) are one of the promising materials for photovoltaic applications because of the suitability of their electrical and optical properties. The $CuInS_2$ thin film is one of I-III-$VI_2$ type semiconductors, which crystallizes in the chalcopyrite structure. Its direct band gap of 1.5 eV, high absorption coefficient and environmental viewpoint that $CuInS_2$ does not contain any toxic constituents make it suitable for terrestrial photovoltaic applications. A variety of techniques have been applied to deposit $CuInS_2$ thin films, such as single/double source evaporation, coevaporation, rf sputtering, chemical vapor deposition and chemical spray pyrolysis. This is the first report that $CuInS_2$ thin films have been prepared by Aerosol Jet Deposition (AJD) technique which is a novel and attractive method because thin films with high deposition rate can be grown at very low cost. In this study, $CuInS_2$ thin films have been prepared by Aerosol Jet Deposition (AJD) method which employs a nozzle expansion. The mixed fluid is expanded through the nozzle into the chamber evacuated in a lower pressure to deposit $CuInS_2$ films on Mo coated glass substrate. In this AJD system, the characteristics of $CuInS_2$ films are dependent on various deposition parameters, such as compositional ratio of precursor solution, flow rate of carrier gas, stagnation pressure, substrate temperature, nozzle shape, nozzle size and chamber pressure, etc. In this report, $CuInS_2$ thin films are deposited using the deposition parameters such as the compositional ratio of the precursor solution and the substrate temperature. The deposited $CuInS_2$ thin films will be analyzed in terms of deposition rate, crystal structure, and optical properties.

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Effects of Se/(S+Se) Ratio on Cu2ZnSn(SxSe1-x)4 (CZTSSe) Thin Film Solar Cells Fabricated by Sputtering

  • Park, Ju Young;Hong, Chang Woo;Moon, Jong Ha;Gwak, Ji Hye;Kim, Jin Hyeok
    • Current Photovoltaic Research
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    • v.3 no.3
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    • pp.75-79
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    • 2015
  • Recently, $Cu_2ZnSn(S_xSe_{1-x})_4$ (CZTSSe) has been received a tremendous attraction as light absorber material in thin film solar cells (TFSCs), because of its earth abundance, inexpensive and non-toxic constituents and versatile material characteristics. Kesterite CZTSSe thin films were synthesized by sulfo-selenization of sputtered Cu/Sn/Zn stacked metallic precursors. The sulfo-selenization of Cu/Sn/Zn stacked metallic precursor thin films has been carried out in a graphite box using rapid thermal annealing (RTA) technique. Annealing process was done under sulfur and selenium vapor pressure using Ar gas at $520^{\circ}C$ for 10 min. The effect of tuning Se/(S+Se) precursor composition ratio on the properties of CZTSSe films has been investigated. The XRD, Raman, FE-SEM and XRF results indicate that the properties of sulfo-selenized CZTSSe thin films strongly depends on the Se/(S+Se) composition ratio. In particular, the CZTSSe TFSCs with Se/(S+Se) = 0.37 exhibits the best power conversion efficiency of 4.83% with $V_{oc}$ of 467 mV, $J_{sc}$ of $18.962mA/cm^2$ and FF of 54%. The systematic changes observed with increasing Se/(S+Se) ratio have been discussed in detail.

Degradation of Pesticides in Wastewater Using Plasma Process Coupled with Photocatalyst (광촉매를 병합한 플라즈마 공정을 이용한 폐수에 함유된 살충제 분해)

  • Jang, Doo Il;Kim, Kil-Seong;Hyun, Young Jin
    • Applied Chemistry for Engineering
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    • v.24 no.1
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    • pp.87-92
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    • 2013
  • Nonthermal plasma hybridized with photocatalysts is proven to be an effective tool to degrade toxic organics in wastewater. In this study, a specially designed dielectric barrier discharge (DBD) plasma system combined with photocatalysts was applied to decompose pestiticides such as dichlorovos, carbofuran and methidathon, which are frequently used in the golf courses and the orange plantations. The degradations of the pesticides in single and coupled systems were evaluated. The single system was used with ozone plasma which consisted of electrons, radicals, ions produced by oxygen gas and air, with and without ultra-violet (UV) irradiation, respectively. The coupled systems utilized the air-derived ozone plasma combined with zinc oxide, titanium dioxide and graphite oxide photocatalyst activated by UV. The graphite oxide was synthesized by a modified Hummer's method and characterized using FTIR spectrometer. It was elucidated that the plasma reaction with graphite oxide (0.01 g/L) brought about almost 100% of degradation degrees for dichlorovos and carbofuran in 60 min, as compared with the performances showed by no catalyst condition. The photocatalyst-hybridized plasma in the presence of UV irradiation was proven to be an effective alternative for degrading pesticides.

Heterogeneous Sensor Data Analysis Using Efficient Adaptive Artificial Neural Network on FPGA Based Edge Gateway

  • Gaikwad, Nikhil B.;Tiwari, Varun;Keskar, Avinash;Shivaprakash, NC
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.13 no.10
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    • pp.4865-4885
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    • 2019
  • We propose a FPGA based design that performs real-time power-efficient analysis of heterogeneous sensor data using adaptive ANN on edge gateway of smart military wearables. In this work, four independent ANN classifiers are developed with optimum topologies. Out of which human activity, BP and toxic gas classifier are multiclass and ECG classifier is binary. These classifiers are later integrated into a single adaptive ANN hardware with a select line(s) that switches the hardware architecture as per the sensor type. Five versions of adaptive ANN with different precisions have been synthesized into IP cores. These IP cores are implemented and tested on Xilinx Artix-7 FPGA using Microblaze test system and LabVIEW based sensor simulators. The hardware analysis shows that the adaptive ANN even with 8-bit precision is the most efficient IP core in terms of hardware resource utilization and power consumption without compromising much on classification accuracy. This IP core requires only 31 microseconds for classification by consuming only 12 milliwatts of power. The proposed adaptive ANN design saves 61% to 97% of different FPGA resources and 44% of power as compared with the independent implementations. In addition, 96.87% to 98.75% of data throughput reduction is achieved by this edge gateway.

Flame Retardancy and Thermal Properties of PVC/ATH Composites Prepared by a Modular Intermeshing Co-rotating Twin Screw Extruder

  • Lee, Hyeongsu;Park, Se-Ho;Lee, Jae-Yeul;Park, Yuri;Jeong, Hobin;Jhee, Kwang-Hwan;Bang, Daesuk
    • Elastomers and Composites
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    • v.51 no.2
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    • pp.147-153
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    • 2016
  • Polyvinyl chloride (PVC) has been used as a general-purpose polymer because of its lower cost, good durability and mechanical properties compared to other materials. However, PVC is vulnerable to heat deformation and generates a toxic gas like hydrogen chloride. Therefore, it is important to delay or prevent the flame retardancy and thermal degradation of the PVC during the processing. It was reported that aluminum trihydroxide (ATH) improved flame retardancy as well as smoke inhibition of the virgin polymer. In this study, PVC composites by addition of ATH were compounded in a modular intermeshing co-rotating twin screw extruder. The PVC composites with different concentrations of ATH (0~5 phr) were analyzed. Flame retardancy of the PVC composite significantly increased depending on the ATH concentration. LOI of the composite also increased with the concentration of ATH. There were no significant differences for the thermal properties of the PVC composites with ATH.