• Applied Chemistry for Engineering
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• v.26 no.4
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• pp.495-504
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• 2015

This work investigated the characteristics of a packed-bed plasma reactor system and the performances of the plasma reactors connected in series or in parallel for the decomposition of ethylene. Before the discharge ignition, the effective capacitance of the ${\gamma}$-alumina packed-bed plasma reactor was larger than that of the reactor without any packing, but after the ignition the effective capacitance was similar to each other, regardless of the packing. The energy of electrons created by plasma depends mainly on the electric field intensity, and was not significantly affected by the gas composition in the range of 0~20% (v/v) oxygen (nitrogen : 80~100% (v/v)). Among the various reactive species generated by plasma, ground-state atomic oxygen and ozone are understood to be primarily involved in oxidation reactions, and as the electric field intensity increases, the amount of ground-state atomic oxygen relatively decreases while that of nitrogen atom increases. Even though there are many parameters affecting the performance of the plasma reactor such as a voltage, discharge power, gas flow rate and residence time, all parameters can be integrated into a single parameter, namely, specific input energy (SIE). It was experimentally confirmed that the performances of the plasma reactors connected in series or in parallel could be treated as a function of SIE alone, which simplifies the scale-up design procedure. Besides, the ethylene decomposition results can be predicted by the calculation using the rate constant expressed as a function of SIE.

• Journal of environmental and Sanitary engineering
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• v.21 no.3 s.61
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• pp.15-26
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• 2006

As traffic in city-centre around the world continues to increase, so levels of atmospheric pollutants continue to rise. High concentrations of NOx can have negative effects on human health, and we must find new ways to reduce their levels in the air we breathe. Nitrogen oxide gas (NOx), consisting of nitrogen monoxide (NO) and nitrogen dioxide $(NO_2)$ produced using $O_3$ oxidation, at a low concentration corresponding to that on roads as a result of exhaust from automobiles, was carried out to evaluate the removal characteristics of NOx through a laboratory-scale biofilter packed with soil as a packing material. A mixture media (yellow soil (30%): soil (40%): compost (10%): a used briquet (20%)) was applied. After about 1day of operation, the removal efficiency for $NO_2$ in all experiments with a constant condition ($25^{\circ}C$ and water humidity (60%)) was over 98%. The retention times of the section between phase I and phase II for formation and reduction of $NO_3$ NO and $NO_2$ on the initial $NO_3$ concentration was 50min $(O_3:195\;ppb),\;55min\;(O_3:925\;ppb),\;65min\;(O_3:1743\;ppb),\;70min\;(O_3:2616\;ppb),\;75min\;(O_3:3500\;ppb)$, respectively The soil biofilter system is a unique technology that purifies urban air by utilizing the natural processes that take place in the soil. Although some of the processes are quite complex, they can broadly be summarized as adsorption onto soil particles, dissolution into soil pore water, and biochemical.

• The Korea Journal of Herbology
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• v.23 no.2
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• pp.9-17
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• 2008

Objectives : The purpose of this report was to provide the information packaging of herbal medicines by analyzing papers. We investigated the packaging materials, packaging methods and expiration date of herbal medicines by analyzing papers of the Korea, Japan and China. Methods : We survey herbal medicine-related law and crude drug monograph of compendium in each three country, we purchased herbal medicine of the Korea, Japan and China in the market and verify the expressed-item in packing paper. In case of Japan, we examine packaging materials, packaging methods, and expiration date of herbal medicine in pharmaceutical company. Results : The pharmaceutical company in japan used the methods of nitrogen gas pouring, vacuum packing for the herbal medicine packaging. The expiration date of the herbal products in Japan is generally 3 to 5 year after packaging. And packaging materials were aluminium and polyethylene. In Korea, pharmaceutical company used airtight packing for the herbal medicine packaging and expiration date of the herbal product were generally 3 year after packaging. Packaging materials were polyethylene, nylon or polyethylene-nylon mixed materials. In China, pharmaceutical company also used airtight packing for the herbal medicine packaging, and the expiration date were generally 5 year after packaging. Packaging materials were polyethylene, wrapping paper-used parcel or tea leaves filter paper. Conclusion : This results can present the basic data for expiration date and preservation methods of the herbal roots in Korea.

• Korean Journal of Food Science and Technology
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• v.25 no.3
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• pp.243-246
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• 1993

For extending the shelf-life of Yukwa (oil puffed rice cake) which is one of the most favorable Korean traditional rice snack, the Yukwa was packed in $O_2$ preventive container and substituted the air with $N_2$ gas or packed with $O_2$ absorbent (ageless sachet). The quality of Yukwa stored at $35^{\circ}C$ was evaluated by POV, AV and TBA including sensory evaluation. The POV of oil in Yukwa of $N_2$ substitute pack and absorbent sachet included were 5.3 and 11.9 meq/kg, respectively, while no packing (control) was 195.5 meq/kg after 90 days storage at $35^{\circ}C$. AV and TBA were also same trend but the gap with the control was not so big. The Yukwa, $N_2$ gas substituted, was better in quality than absorbent treatment in sensory evaluation and no difference was detected in quality of 90 days storage Yukwa at $35^{\circ}C$ with 15 days. The main reason for lower sensory score of absorbent treatment was that the $O_2$ absorbent also absorbed the flavor component of Yukwa.

• Journal of Environmental Health Sciences
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• v.34 no.1
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• pp.101-107
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• 2008

Bio-filtration utilizes microorganisms fixed to a porous medium to metabolize pollutants present in an air stream. The microorganisms grow in a bio-film on the surface of a medium or are suspended in the water phase surrounding the medium particles. Therefore, bio-filter support media play one of the most important key roles in bio-filtration of gas phase pollutants. To characterize and select the appropriate support media, gas adsorption capacity and microorganism immobilization were investigated in lab-scale experiments for the selected target support media which were compost I (compost from lab-scale process), compost II (compost from municipal facility), bark, wood chip, orchid stone and vermiculite. As odor materials, ammonia and trimethylamine were utilized. From the result of experiments, bark was superior to any other support media tested in adsorption capacity as much as 12.5 mg ammonia per 1 g bark. In trimethylamine adsorption, bark and wood chip showed a remarkable results of 21.1 and 14.1 mg/g respectively. On the other hand, microorganism fixation test determined by the count of nitrogen oxidizing microbes population, the compost II and wood chips showed the best results. Considering the characteristics of materials and the operating condition of the bio-filter, bark, wood chip, and compost II are applicable to the support media of bio-filter when they are appropriately blended on the basis of studying the media pH, packing porosity and moisture contents.

• Applied Biological Chemistry
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• v.27 no.3
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• pp.139-145
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• 1984

For the ultimate manufacture of vinegar with watermelon juice, we examined the preliminarily alcoholic fermentation of watermelon juice using Saccharomyces cerevisiae, Saccharomyces cerevisiae var. ellipsoideus and Kluyveromyces fragilis. The juice contained 3.2% total reducing sugar by the Somogyi-Nelson method. Strains of yeast culture, pH, temperature and concentration of sugar in the juice were important factors affecting alcoholic fermentation. Saccharomyces cerevisiae var. ellipsoideus produced 5.3% alcohol from the juice fortified with 12% glucose under the conditions of pH 5.73 and $27^{\circ}C$ for 8 days. Generally, small quantities of various salts and N-sources affected little the alcoholic fermentation of the juice. The sterilization of the juice by autoclaving improved efficiency of fermentation than that by $SO_2$ sterilization. Determination of alcohol was carried out by the gas chromatographic method using Chromosorb W: Carbowax as packing material.

• Safety and Health at Work
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• v.9 no.3
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• pp.356-359
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• 2018

This case report attempts to present a case of acute toxic hepatitis in fire extinguisher manufacturing workers exposed to 2,2-dichloro-1,1,1-trifluoro-ethane (HCFC-123) in August 2017 in Korea. Twenty-two-year-old male workers were exposed to HCFC-123 for 1.5 hours one day and for 2.5 hours the other day, after which one worker died, and the other recovered after treatment. The workers were diagnosed with acute toxicity of hepatitis. However, exposure levels of HCFC-123 were not known with no work environment measurement done. Therefore, this study was conducted to estimate the exposure concentration of HCFC-123 via a job simulation experiment. In the simulation, the HCFC-123 exposure concentration was measured with the same working practice and working time as with the workers aforementioned. As a result, the workers who infused HCFC-123 into storage tanks were estimated to be exposed to HCFC-123 at a concentration of $20.65{\pm}10.81ppm$, and a mean concentration of area samples within a working radius were estimated as $70.30{\pm}18.10ppm$. Valve assembly workers working on valves of a fire extinguisher filled with HCFC-123 were exposed to HCFC-123 at concentrations of $91.65{\pm}4.03ppm$ and $115.55{\pm}7.28ppm$, respectively, in the simulation, and area samples simulated within the working radius were also found to be high with concentrations of $122.75{\pm}91.15ppm$ and $126.80{\pm}60.25ppm$, respectively. Nitrogen gas packing workers, who did not handle HCFC-123 directly, were exposed to the agent at a concentration of $71.80{\pm}8.49ppm$. These results suggest that exposure to HCFC-123 at high concentrations for 1.5-2.5 hours caused acute toxic hepatitis in two workers.

• Horticultural Science & Technology
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• v.28 no.3
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• pp.522-527
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• 2010

Onion has been reported to contain various organosulfur compounds which have antibiotic and anticarcinogenic properties and flavonoid like quercetin which is a valuable natural source of antioxidants. Carbohydrates in onion constitute about 80% of dry matter, and the major non-structural carbohydrate of onion bulb is fructo-oligosaccharides, well known as fructan, followed by glucose, fructose, and sucrose. The sugar concentration is associated with dormancy and storage life of onion, occurring as decrease in glucose, fructose and fructan, particularly towards the end of storage. Forced air pre-drying for 15-20 days at room temperature is an essential procedure to reduce freezing injury and sprouting, then onion bulbs can be stored at $0^{\circ}C$ for 6 months to control sprouting and decay. Bacterial soft rot caused by $Erwinia$ and $Pseudomonas$ is the main postharvest disease when the bulbs are infected with the bacteria and stored at room temperature. Browning in sliced onion is due to oxidation of phenolic compounds by polyphenol oxidase and it can be inhibited by citric acid treatment, packing with nitrogen gas, and polyethylene film.