• Journal of Korean Society for Atmospheric Environment
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• v.5 no.2
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• pp.55-71
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• 1989

This study was carried out to determine the ozone concentration to behaviour and the factors to be influenced the variation of its concentration in the ambient air in Seoul. Measurements of ozone concentrations were made at 10 monitoring station to take care of SIHE (Seoul Institute of Health & Environment) during December 1987 to November 1988, also measured the hourly average concentration of sulfur dioxide, total suspended particulate, nitrogen oxide $(NO & NO_2)$, carbon monoxide, hydro carbon $(n-CH_4 & THC)$ and meteorological factors, that is, temperature, humidity, wind velocity wind direction and ultraviolet intensity etc, for the same period at same place. The basis of the data obtained were analyzed statistically along with the various data. The results were as follows; 1. The annually arithmetic mean concentration of ozone for the 10 sites during one years was 10.0 ppb and ranged from 3.1 $\pm$ 4.5ppb at the Kuro industrial complex to 17.2 $\pm$ 18.7 ppb at the Ssangmun site. 2. The frequency of hours on which oxidant concentrations exceeded the present short term standard of ozone (100 ppb) were 78 times. 3. The diurnal patterns of hourly ozone concentrations in Seoul area was a typical bi-modal variation which have 4 to 5 a.m. peak and 3. to 4 p.m peak. 4. The time ozone of highest ozone concentration in a whole day and hight was 1 to 5 p.m and 90.9 percent of appearence rate. 5. The diurnal patterns of hourly ozone concentrations in Seoul were on the whole the order of daytime from 5.8ppb to 28.7 ppb evening from 1.7 to 18.7 ppb night time from 1.9 to 9.3 ppb daybreak from 1.4ppb according to measuring sites, and the highest that observed at the Ssangmun area while the lowest was the Kuro industrial complex monitor sites. 6. The weekly variation of ozone concentration was the higher level ozone concentration in the day of the week occured sunday-monday and weekend but the decrease were observed from wednesday to thursday.

• Korean Journal of Microbiology
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• v.29 no.6
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• pp.380-386
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• 1991

Three types of soluble cytochrome c were purified to homogeneity from Methylobacillus sp. strain SK1 which grows only on methanol. Cytochrome c-I was purified 58.5-fold in seven steps. Cytochrome c-II and c-III were purified 57.3- and 122.1-fold in eight steps, respectively. The molecular weights of the cytochrome c-I was determined to be 12,500, while those of the cytochrome c-II and c-III were 16,000. The isoelectric points of the c-I, c-II and c-III were found to be 8.8, 6.6, and 6.6 respectively. The spectrum of reduced cytochrome c-I showed .alpha.-, .betha.-, .gamma.-peaks at 551.4, 522.2, and 416.6nm. The peaks for c-II were found at 551.0, 521.6, and 416.5nm, while those for c-III were shown at 551.2, 521.8, and 416.0 nm. The spectra of oxidized cytochrome c-I, c-II, and c-III showed .gamma.-peak at 411.8, 409.0, and 410.2 nm, respectively. The absorption coefficients of .alpha.- and .gamma.-peak for c-I in the reduced state were determined as 47 and 197 $mM^{-1}$ $cm^{-1}$ , respectively. The coefficients of .alpha.- and .gamma.-peak for c-II were determined to be 43 and 137 $mM^{-1}$ $cm^{-1}$ , while those for c-III were 41 and 172 $mM^{-1}$ $cm^{-1}$ , respectively. The c-I and c-III were found to bind carbon monoxide.

• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.3
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• pp.358-364
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• 2016

The combustion and exhaust emission characteristics in a spark ignition (SI) engine with various test fuels (bioethanol - gasoline blends) and air-fuel ratio were investigated in this research. To investigate the influence of the excess air ratio and ethanol blends on the combustion characteristics such as the cylinder pressure, rate of heat release (ROHR), and fuel consumption rate were analyzed. In addition, the reduction effects of exhaust emissions such as carbon monoxide (CO), unburned hydrocarbon (HC), and oxides of nitrogen (NOx) were compared with those of neat gasoline fuel under the various excess-air ratios. The results showed that the peak combustion pressures and the ROHR of bioethanol fuel cases were slightly higher than those of gasoline fuel at all test ranges and fuel ratio. As compared with gasoline fuel (G100) at each given excess air ratio, BSFC of bio-ethanol was increased. The CO, HC, NOx emissions of bio-ethanol blends were lower than those of gasoline fuel under overall experimental conditions.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 1997.11a
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• pp.85-92
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• 1997

Flammability of non-flame-retardant and flame-retardant materials was studied by using cone calorimeter Also, relations between the results obtained by using cone calorimeter and those obtained by the flammability test of japanese fire Service Law were examined. The results are as follows: 1) The ignition time of the molten specimens is relatively long, whereas the ignition time of the non-molten specimens is short. None of remarkable difference of the ignition time has been found between non-flame-retardant and flame-retardant materials specimens. 2) The peak heat release rates of flame-retardant materials are smaller than those of non-flame- retardant materials. 3) The carbon monoxide and smoke evolved from flame-retardant materials generate much more than those evolved from non-flame-retardant materials. 4) Even if flame-retardant materials are passed by the flammability test of Japanese Fire Service Law, they burn easily under external radiative heating condition.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.29 no.2
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• pp.45-49
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• 2019

Relatively fine silicon carbide (SiC) crystalline aggregates have been synthesized with the carbonized rice husks, paper sludge, coffee grounds as the carbon sources and the silica powder. The main reaction source to obtain silicon carbide (SiC) aggregates from the mixture of carbon sources and silica was inferred as the gaseous silicon monoxide (SiO) phase, being created from this mixture through the carbothermal reduction reaction. The silicon carbide (SiC) crystalline aggregates, fabricated from the carbonized rice husks and paper sludge, coffee grounds and silica ($SiO_2$) powder, were investigated by XRD patterns, FE-SEM and FE-TEM images. In these specimens, obtained from the carbonized rice husks, paper sludge and silica, XRD patterns showed rather high strong peak of (111) plane near $35^{\circ}$. The FE-TEM images and patterns of specimens, synthesized from carbonized rice husks, paper sludge, coffee grounds and silica under Ar atmosphere, showed relatively fine particles under $1{\mu}m$ and crystalline peak (110) of silicon carbide (SiC) diffraction pattern.

• Applied Chemistry for Engineering
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• v.27 no.1
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• pp.39-44
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• 2016

This study was to investigate the characteristics of combustion toxic gases of pinus rigida specimens treated with chemical additives such as pyrophosphoric acid (PP)/ammonuium ion ($NH_4{^+}$), methylenepiperazinomethyl-bis-phosphonic acid (PIPEABP) and $PIPEABP/NH_4{^+}$. Each pinus rigida plates was painted in three times with 15 wt% of each chemical additives in the aqueous solution. After drying these specimens at room temperature, the production of combustion gases and smoke was examined by the cone calorimeter (ISO 5660-1). As a result, the peak mass loss rate time (PMLR time) treated with chemicals was delayed upto 10.5~47.4% compared to that of using untreated specimen. In addition, the peak production of carbon monoxide ($CO\;_{peak}$) of 32.1~71.4% and total smoke release rate (TSRR) of 15.6~43.6% for test pieces treated with the chemical additive were higher than that of using the virgin plate. In particular, for the specimens treated with the chemical additive, the rate of smoke release (RSR) 29.4~41.5% was obtained higher than that of untreated plate except the specimen treated with $PP/4NH_4{^+}$. It can thus be concluded that the treatment using the chemical additive could partially increase the combustion-retardation properties of the species when compared to those of the virgin plate.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.7
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• pp.609-615
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• 2015

In this study, the combustion and exhaust emission characteristics in a gasoline direct injection engine with variations of the bio-ethanol-gasoline blending ratio and the excess air factor were investigated. To investigate the effects of the excess air factor and the bio-ethanol blends with gasoline, combustion characteristics such as the in-cylinder combustion pressure, rate of heat release (ROHR), and the fuel consumption rate were analyzed. The reduction of exhaust emissions such as carbon monoxide (CO), unburned hydrocarbon (HC), and nitrogen oxides ($NO_x$) were compared with those of gasoline fuel with various excess air factors. The results showed that the peak combustion pressure and ROHR of bio-ethanol blends were slightly higher and were increased as bio-ethanol blending ratio is increased. Brake specific fuel consumption increased for a higher bio-ethanol blending ratio. The exhaust emissions decreased as the bio-ethanol blending ratio increased under all experimental conditions. The exhaust emissions of bio-ethanol fuels were lower than those of gasoline.

• Journal of Microbiology and Biotechnology
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• v.20 no.3
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• pp.532-541
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• 2010

Peroxidase-like activity of Vitreoscilla hemoglobin (VHb) has been recently disclosed. To maximize such activity, two catalytically conserved residues (histidine and arginine) found in the distal pocket of peroxidases have successfully been introduced into that of the VHb. A 15-fold increase in catalytic constant ($k_{cat}$) was obtained in P54R variant,which was presumably attributable to the lower rigidity and higher hydrophilicity of the distal cavity arising from substitution of proline to arginine. None of the modifications altered the affinity towards either $H_2O_2$ or ABTS substrate. Spectroscopic studies revealed that VHb variants harboring the T29H mutation apparently demonstrated a spectral shift in both ferric and ferrous forms (406-408 to 411 nm, and 432 to 424-425 nm, respectively). All VHb proteins in the ferrous state had a $\lambda_{soret}$ peak at ~419 nm following the carbon monoxide (CO) binding. Expression of the P54R mutant mediated the downregulation of iron superoxide dismutase (FeSOD) as identified by two-dimensional gel electrophoresis (2-DE) and peptide mass fingerprinting (PMF). According to the high peroxidase activity of P54R, it could effectively eliminate autoxidation-derived $H_2O_2$, which is a cause of heme degradation and iron release. This decreased the iron availability and consequently reduced the formation of the $Fe^{2+}$-ferric uptake regulator protein ($Fe^{2+}$-Fur), an inducer of FeSOD expression.

• Safety and Health at Work
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• v.5 no.4
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• pp.234-237
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• 2014

Background: Inhalation of asbestos fibers can lead to adverse health effects on the lungs. This study describes lung function profiles among individuals with nonmalignant asbestos-related disorders (ARDs). Methods: The study population was from the Workers' Compensation (Dust Diseases) Board of New South Wales, Sydney, Australia. Lung function measurements were conducted in males with asbestosis (n = 26), diffuse pleural thickening (DPT; n = 129), asbestosis and DPT (n = 14), pleural plaques only (n = 160) and also apparently healthy individuals with a history of asbestos exposure (n = 248). Standardized spirometric and single-breath diffusing capacity for carbon monoxide ($DL_{CO}$) measurements were used. Results: Mean age [standard deviation (SD)] was 66.7 (10.3) years for all participants. Current and ex-smokers among all participants comprised about 9.0% and 54.8%, respectively. Median pack-years (SD) of smoking for ex- and current-smokers were 22.7 (19.9). Overall 222 participants (38.6%) and 139 participants (24.2%) had forced expiratory volume in 1 second ($FEV_1$) and forced vital capacity (FVC) measurements < 80% predicted, and 217 participants (37.7%) had $FEV_1/FVC$ results < 70%. A total of 249 individuals (43.8%) had DLCO values < 80% predicted and only 75 (13.2%) had DLCO/VA results < 80% predicted. A total of 147 participants (25.6%) had peak expiratory flow (PEF) measurements < 80% predicted. The presence of ARDs lowered the lung function measurements compared to those of healthy individuals exposed to asbestos. Conclusion: Lung function measurement differs in individuals with different ARDs. Monitoring of lung function among asbestos-exposed populations is a simple means of facilitating earlier interventions.

• The Journal of Natural Sciences
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• v.8 no.2
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• pp.119-127
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• 1996

The effect of sodium hydroxide treatment on some physicochemical properties of zeolite mordenite mineral was studied with chemical analyses, powder X-ray diffraction, thermal analyses, infrared analysis, measurement of carbon dioxide adsorption and gas chromatography. Mordenite mineral from tuffaceous rocks in Yeongil and Wolsung area was used as a starting material and treated with 0.1-5N NaOH aqueous solution at about $95^{\circ}C$ in the water bath for three hours.At the concentration of sodium hydroxide below 0.5N, all chemical compositions in the tuff were virtually insoluble and the mordenite structure did not change. At the concentration above 1N, the chemical compositions such as silica, alumina, etc., were dissolved. The dissolution ratio of silica was lager than that of alumina, and the ratio of silica to alumina in the tuff decreased sharply in the concentration range of 2 to 3N. Intensity of X-ray diffraction peak of mordenite (202) plane and the adsorbed amount of carbon dioxide also decreased with the increasing concentration of sodium hydroxide above 1N. These decreases corresponded to the degree of mordenite structure collapsed.The separation of gas chromatography of nitrogen, oxygen and carbon monoxide was not affected by the sodium hydroxide treatment, but elution peaks of methane and krypton tended to be broadened and their retention time was shortened. The elution peaks of both methane and krypton tended to be overlapped with those of nitrogen and oxygen.