• 한국환경과학회지
• /
• 제30권11호
• /
• pp.967-977
• /
• 2021

From January 1, 2020, the International Maritime Organization has implemented a global regulation, known as IMO 2020, to reduce the sulfur content in fuel oil of ships from 3.5% to 0.5%. In this study, we used data from air monitoring stations to evaluate the change in air quality at New Port and North Port in Korea areas after the regulation was implemented. The concentration of SO₂ and NO₂ was higher in the port areas than in the surrounding areas due to exhaust gas from ships and vehicles. However, the SO₂ concentration decreased by more than 50% in the port area, demonstrating the efficiency and positive effect of the IMO 2020 sulfur limit.

• 한국전기화학회:학술대회논문집
• /
• 한국전기화학회 1999년도 제2회 총회 및 춘계학술발표회
• /
• pp.72-72
• /
• 1999

• 한국환경보건학회지
• /
• 제16권2호
• /
• pp.21-29
• /
• 1990

This study investigated to find out the patterns of the wind direction and wind speeds influenced by concentration of sulfur dioxide in Taegu area for a year in 1988.The results were as follows: Prevailing wind by months where easterly wind from May to September and the other months were westerly and / or west-north-westerly wind. Condition of calm was the most at December(8.6%). Prevailing wind by seasons were westerly and easterly wind in spring and autumn, east-north-easterly and/or west-south wind in summer, the other hand, west-south-westerly and/or west-north-westerly wind in winter. Mean concentration of sulfur dioxide (SO$_{2}$) at each sites were influenced by prevailing wind and location of industrial estates. Mean wind speeds by times were the highest at the before and after 4 P.M.,but the lowest at the before and after 5 A.M. Average wind velocity were highest at Spring (3.38m / sec).

• 한국대기환경학회지
• /
• 제15권5호
• /
• pp.649-655
• /
• 1999

Biofiltration of polluted gas streams contained $H_2S$ was studied. The experiments were performed in a laboratory-scale reactor with a porous ceramic media inoculated with sulfur oxidizing bacterium, TAS which was isolated from activiated sludge. The concentration of $H_2S$ in the inlet gas varied from 109 to 3,841 ppm, at the various space velocities(SV) of 50 $h^{-1}$ to 250 $h^{-1}$. Various tests have been conducted to evaluate the effects of such parameters as pH, concentration of sulfate ion and retention time on the pressure drop and maximum elimination capacity. The removal efficiency of $H_2S$ decreased as the $H_2S$ concentration or gas velocity increased in the inlet gas. Pressure drop was insignificant in this system. The maximum elimination capacity could reach up to 16.35g-S/kg-dry packing material/day.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2001년도 하계학술대회 논문집
• /
• pp.917-920
• /
• 2001

Effects of addition of manganese and final reduction on segregation behavior of sulfur and final mangetic induction during final annealing have been investigated in the 300 ppm sulfur-contained 3% silicon-iron alloy strips with or without manganese. At the same concentration of sulfur, lower final reduction is favorable for final Goss texture. This is because the probability that the initial Goss grains survive under the highly segregated sulfur atmosphere and grow selectively within the segregated sulfur-free time range becomes higher. In the case of 3% silicon-iron with manganese, much lower magnetic induction was obtained, although the weak final reduction of 30% is given to the alloy, comparative to the 40%. This is because MnS particles acted as an reducer in the primary grain size.

• 한국환경보건학회지
• /
• 제2권1호
• /
• pp.29-31
• /
• 1975

This experiment Was carried out under two points of view, from May 1st to the end of 1973. One was the comparative determination of the activation factor of Lead dioxide by kinds in measuring of Sulfur oxides concentration by $PbO_2$ cylinder method, and the other was the comparison that result with the record of auto analyzer. Five measuring sites were selected out of Seoul City. Three kinds of Lead dioxide made in Japan (B,C and D) were compared with Standard $PbO_2$ (A for use in Determination of Sulphur in the atmosphere, purity 99% up) made in British Institution, and monthly measuring was conducted at every sampling site. The recording by auto analyzer (Beckman Model 906-A $SO_2$ Analyzer) was conducted once or twice a month for 24 hours at each sampling site during the same period. And some significant results were obtained. 1. In comparative experiments to determine the activation degree of three kinds of Lead dioxide (B,C and D), the obtained correction factor of B reagent was 1.09, 1.16 in C and 1.30 in D against Standard $PbO_2$ (A). Therefore, it should be in need of standardization or clear statement about the reagents for use, in determination sulfur oxides by $PbO_2$ cylinder method. 2. Generally, the concentration of Sulfur dioxide by wilkins' convertion method from $SO_3$ showed about 20-30% higher than those by Auto analyzer.

• 전기화학회지
• /
• 제13권2호
• /
• pp.110-115
• /
• 2010

The plasticized polymer electrolytes based on polyvinylidene fluoride-co-hexafluoropropylene (P(VdF-co-HFP)), tetra (ethylene glycol) dimethyl ether (TEGDME), and lithium perchlorate ($LiClO_4$) are prepared for the lithium sulfur batteries by solution casting with a doctor-blade. The polymer electrolyte with EO : Li ratio of 16 : 1 shows the maximum ionic conductivity, $6.5\;{\times}\;10^{-4}\;S/cm$ at room temperature. To understand the effect of the salt concentration on the electrochemical performance, the polymer electrolytes are characterized using electrochemical impedance spectroscopy (EIS), infrared spectroscopy (IR), viscometer, and differential scanning calorimeter (DSC). The optimum concentration and mobility of the charge carriers could lead to enhance the utilization of sulfur active materials and the cyclability of the Li/S unit cell.

• 한국식품저장유통학회지
• /
• 제30권6호
• /
• pp.905-917
• /
• 2023

The optimal fermentation conditions for producing fermented black soybeans rich in sulfur-containing amino acids were investigated. Response surface methodology monitored fermentation conditions. A central composite design examined the effect of independent variables: enzyme concentration (X₁) and fermentation time (X₂) on yield and methionine content. Both factors significantly influenced these dependent variables. Enzyme concentration more profoundly affected amino nitrogen content than fermentation time. β-Glucan content and cystine level were primarily affected by fermentation time. We elicited each variable's regression formula and identified optimal fermentation conditions for functional compounds. The predicted optimum conditions were an enzyme concentration of 0.28-0.32% and a fermentation time of 58.0-62.0 min. Under these optimal conditions, each black soybean variety's sulfur amino acid content ranged from 818.62 to 922.62 mg/100 g, demonstrating significant variety differences.

• 농업과학연구
• /
• 제44권2호
• /
• pp.261-271
• /
• 2017

The aim of this study was to investigate the amount of glucosinolates (GSLs) in kale sprouts (Brassica oleracea L. var. acephala) ('TBC') according to different concentrations of sulfur ions in sprout's nutrient solutions (0.0, 0.5, 1.0, and 2.0 mM) and to different light sources [Fluorescent lamp, Red, Blue, and Mix (R+B) LED]. Kale sprouts were cultivated in a growth chamber for 13 days in sulfur solutions. Kale sprouts were treated with fluorescent lamp and LED light sources for 5 days, from eight days after sowing to harvest. Amount of seven types of GSLs (progoitrin, sinigrin, 4-hydroxyglucobrassicin, glucobrassicin, 4-methoxyglucobrassicin, gluconasturtiin, and neoglucobrassicin) were measured in kale sprouts after harvest. The total GSL content was influenced by different sulfur solution concentration, and it was the highest at S 0.5 mM ($172.54{\mu}mol{\cdot}g^{-1}DW$) and the lowest at S 2.0 mM ($163.09{\mu}mol{\cdot}g^{-1}DW$). The GSL content was influenced by different light source, and it was the highest with Red LED ($159.23{\mu}mol{\cdot}g^{-1}DW$) and the lowest with Blue LED ($147.57{\mu}mol{\cdot}g^{-1}DW$). As the sulfur solution concentration increased under all light source, progoitrin and sinigrin contents tended to decrease while glucobrassicin content showed an upward tendency for all of the light sources. The content of glucobrassicin was higher than that of progitrin when treated with sulfur solutions for all LED light sources. Sinigrin, which has excellent anti-cancer effects, showed the highest rate (92.2%) among all the GSLs, under all of the light sources.

• 한국초지조사료학회지
• /
• 제42권3호
• /
• pp.195-200
• /
• 2022

Sulfur is an essential element in plants, including amino acids, vitamin synthesis, and acting as an antioxidant. However, the interaction between endogenous sulfur and proline synthesis has not been yet fully documented. White clover (Trifolium repens L.) is known as a species highly sensitive to sulfate supply. Therefore, this study aimed to elucidate the role of sulfur in regulating proline metabolism in relation to ammonia detoxification and hydrogen peroxide (H₂O₂) accumulation in white clover. The detached leaves of white clover were immersed in solution containing different concentration of sulfate (0, 10, 100, and 1000 mM MgSO₄). As MgSO₄ concentrations were increased, the concentration of H₂O₂ increased up to 2.5-fold compared to control, accompanied with H₂O₂ detection in leaves. Amino acid concentrations significantly increased only at higher levels (100 and 1000 mM MgSO₄). No significant difference was observed in protein concentration. Proline and ∆^1-pyrroline-5-carboxylate (P5C) concentrations slightly decreased at 10 and 100 mM MgSO₄ treatments, whereas it rapidly increased over 1.9-fold at 1000 mM MgSO₄ treatment. Ammonia concentrations gradually increased up to 8.6-fold. These results indicate that exogenous sulfur levels are closely related to H₂O₂ and ammonia synthesis but affect proline biosynthesis only at a higher level.