• Journal of the Korean Society of Marine Environment & Safety
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• v.17 no.2
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• pp.123-129
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• 2011

A study on the occurrence and movement of marine debris is required for protecting the marine environment and ecosystem from marine pollution. The aim of this study is to show annual production and movement characteristics through analysis for the flow path, composition and the sources of marine debris. This study analyzed the distribution and characteristics of marine debris collected in the region of $100\;m{\times}20\;m$($=2,000\;m^2$) at the Daekwang Beach in the Yellow Sea. During the collection period from 2008 to 2010, the total weight of the marine debris was 1,445 kg in this site. The most marine debris was plastic amounting to 46.5% of the whole collection; the rest were styrofoam(20%) and wooden material(12.6%). The amount of marine debris mused from foreign country observed 155.5 kg, more than 90% of them was plastic came from China such as buoys. Additionally, this study analyzed seasonal change if marine environment to understand occurrence amount change if marine debris. 2009 and 2010 was high occurrence ratio in season that the north wind is very strong and the occurrence rate appeared highest by 40% in the summer(July) of 2008 that appeared westbound tidal current. Overall, marine Debris mused from foreign country was high occurrence ratio in January, May and then November has a lot of quantity secondly. While, occurrence ratio was the highest by 46% summer(July) in 2008, but in 2009 and 2010 showed the lowest rate to 4%.

• Food Science and Preservation
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• v.22 no.6
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• pp.788-795
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• 2015

The efficacy of an experimentally designed cold chain container and a currently used styrofoam container was investigated with respect to important factors affecting the quality of fresh beef during storage under different conditions. The temperature in the TEPP-1 container was maintained at $5^{\circ}C$ using a phase change material (PCM) during transport and delivery. During storage in the TEPP-1 container, no significant difference was observed in pH of beef, but color decreased slightly, which does not affect the desire to purchase. After storage for 7 days, the rate of VBN and TBA in the TEPP-1 container, was lower than that in the TEPP-2 container. Drip loss was lower in the TEPP-1 container (0.87%) than in the TEPP-2 container (1.78%). No significant changes were observed in microbal count until 4 days in either of the containers, but after storage for 7 days, the count increased significantly. Microbial count in TEPP-1 was 6.65 log CFU/mL and that in TEPP-2 was 7.62 log CFU/mL. The results of sensory evaluations indicated that the overall acceptability of beef after storage for 7 days was better in the TEPP-1 container than in the TEPP-2 container. The EPS container was inferior in comparison with TEPP-1 and TEPP-2. It was impossible to continue the experiment using the EPS container after 3 days. These results suggest that the experimentally designed TEPP-1 container can be used for beef transport and delivery for 7 days without significantly affecting the quality of beef.

• Korean Journal of Medicinal Crop Science
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• v.28 no.2
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• pp.152-166
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• 2020

Background: Ginsenosides, which have various physiological activities, are known to be abundant in the leaves and roots of ginseng. Ginseng sprouts can be used as a fresh vegetable and roots, stems, and leaves of ginseng can be consumed. This study aimed to investigate the effect of carbon dioxide treatment and the modified atmosphere (MA) packaging method in suppressing quality deterioration during the distribution of ginseng sprouts. Methods and Results: Ginseng sprouts were packed using Styrofoam, barrier film + non gas treatment, barrier film + gas treatment, 15 ㎛ polyamide (PA) double film + non gas treatment, 15 ㎛ PA double film + gas treatment, 25 ㎛ PA film + non gas treatment, or 25 ㎛ PA film + gas treatment. Quality parameters including gas composition, relative humidity, chlorophyll SPAD (Soil Plant Analysis Development) value, firmness, and rate of quality loss in ginseng sprouts were monitored at the following temperatures: 20℃, and 10℃. Ginseng sprouts packaged with 25 ㎛ PA film showed loss in quality because of wilting owing to low relative humidity within the film. Chlorophyll and firmness did not differ between film and gas treatments. The time point at which the combined loss from softening and decay owing to fungal, and bacterial infection and wilt reached 20% was considered the limit of distribution. At 20℃, the packaging not included in the 20% distribution loss rate limit or up to 7 days was 15 ㎛ PA double film + gas treatment. At 10℃, the packaging not included in the 20% distribution loss rate limit for up to 18 days were barrier film + gas treatment and 15 ㎛ PA double film + gas treatment. Conclusions: The film packaging suitable for the distribution of ginseng sprouts was found to be the barrier film and PA film with low gas permeability and maintaining hygroscopicity at 95% relative humidity. To prevent the loss in quality of ginseng sprouts, gas treatment (8% of O₂ and 18% of CO₂) in the film was found to be more suitable than no gas treatment for inhibition of decay.

• Magazine of the Korean Society of Agricultural Engineers
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• v.35 no.2
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• pp.92-103
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• 1993

A sunday system with a horizontal bin-type composter was constructed and operated to evaluate its composting performance for four days for each test in October, 1992. A sundry system is one of popular systems for composting livestock manure, of which main benefit is to utilize unlimited, clean, and free solar radiation. A rectangular concrete bin(composter) with dimension of 300cm(length) X90cm(width) X60cm(height) was bedded alternatively with four lanes of aeration pipes and heating pipes, and was insulated at three walls with 50mm styrofoam. Each aeration pipe of a diameter of 25mm had 4mm perforated holes at every 15cm longitudinally, and supplied air of about 2m$^3$/min to the composter to maintain aerobic condition . A stirrer rotating at 1 rpm made one round trip every 20 minutes on the conveying chain along the the length of the composter. Five tests (Test 1~Test 5) were implemented to evaluate the composting effectiveness of a sundry system with a horizontal bin-type composter. Treatments of two levels of the mixture ratio of swine manure and paper sludge cakes(manure : paper sludge cakes= 1 : 4 and 1 : 2) and two levels of the water content(W/C ; 70% and 50%) were made to test the significance of the physicochemical properties for decomposition of the mixture materials. Temperature, C/N ratio, water content, microbial activity of the composting materials were taken measurements to evaluate its performance with the lapse of composting time for tests. A small-scale sundry system with a bin-type composter did not appear to be an appropriate system for composting livestock manure. Since heat generation by the composting materials could not overcome heat loss due to areation in a small-scale composter, a proper thermal enviroment could not be maintained to propagate massively thermopilic microorganism relatively in a short period of time. Different from the result of Chol et al.(1992) 6), a temperature variation of the composting materials did not show the peak clearly and C/N ratio didn't lower with time as expected. Mesophilic microoragnism seemed to play an important role for decomposition of the mixture materials. A sundry system with a bin-type composter may be good for a large-scale livestock farm household which may produce enough animal manure. Therefore a decision should be made very carefully to choose a system for composting livestock waste.

• Journal of the Korean Institute of Gas
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• v.18 no.5
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• pp.47-51
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• 2014

This paper is to analyze and study the fire examples in respect of intake and exhaust, alternator tuning and inflow of inflammables on exhaust part in a car. In the first example, the driver diverted the intake and exhaust system for tuning of a car. Stopping a car to rest for moment, the flammable styrofoam scrap go into exhaust pipe that installed with exhaust manifold newly. It certified the fact that catched fire gradually, furthermore enlarged the fire by leaking fuel. In the second example, the driver enlarged the generator performance to divert the audio system in side room., it knew the fact that the electric wiring connected with generator gave the cause of outbreak a fire by overheating. In the third example, the serviceman replaced the engine oil using funnel-shaped, he put the a bottle of plastic pat onto engine cover carelessly. Consequentially, it found the fire occurrence in the engine room. Therefore, the driver never divert the intake and exhaust and generator construction of a car abnormally. Also, repairing and inspecting a car, the serviceman have a care to not occur the fire by inflammables.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.5
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• pp.675-682
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• 2021

Fire accidents on land and at sea can cause serious casualties; specifically, owing to the nature of marine plants and ships, the mortality rate at sea from suffocation in confined spaces is significantly higher than that on land. To prevent such cases of asphyxiation, it is essential to install ventilation fans that can outwardly direct these toxic gases from fires; however, considering the scale of marine fires, the installation of large ventilation fans is not easy owing to the nature of marine structures. Therefore, in this study, we developed a new concept for fire safety technology to control toxic gases generated by fires from applied direct current (DC) electric fields. In the event of a fire, most flames contain large numbers of positive and negative charges from chemi-ionization, which generates an "ionic wind" by Lorentz forces through the applied electric fields. Using these ionic winds, an experimental study was performed to artificially control the fire smoke caused by burning paper and styrofoam, which are commonly used as insulation materials in general buildings and ships. The experiments showed that a fire smoke could be artificially controlled by applying a DC voltage in excess of ±5 kV and that relatively effective control was possible by applying a negative voltage rather than a positive voltage.

• Journal of Marine Life Science
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• v.7 no.2
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• pp.205-212
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• 2022

Transport is essential in the farming process of farmed fish and is one of the physical stress factors such as sorting. The effect of water temperature and anesthesia during low salinity transport was confirmed. In the experimental group, the water temperature was set to 20℃ (natural water temperature, NWT), 15℃ (cooling water temperature, CWT) respectively, in water with a salinity concentration of 35‰, 15‰ and an anesthetic (anesthesia, Anes., Sigma USA) was diluted and mixed to 50 ppm. A styrofoam box (66×42×20 cm) was used as a transport container, and 8 flounder were accommodated and transported in a plastic bag injected with 3 ℓ of seawater and liquid oxygen. As a result of the study, the concentration of cortisol before transport increased significantly from 2.4±0.1 ng ml^-1 in the experimental groups except for the CWT+35‰ group (16.7±12.8 ng ml-1). The K⁺ concentration slightly increased from 3.1±0.0 mEq l^-1 before transport to 4.5±1.1 mEq l^-1 in the NWT+15‰ group, showing no difference, and significantly increased in all other experimental groups. There was no effect on changes in blood characteristics, and water temperature and anesthetic had a negative effect on osmotic control due to stress. AST and ALT were not affected.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.3
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• pp.62-72
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• 2022

In this study, a miniaturized GPS band(L₁ : 1.575 GHz) antenna that can be mounted on a small drone is proposed. The miniaturization was designed by applying the perturbation method based on the λ/4 microstrip antenna and lengthening the current path at the edge of the patch. The miniaturized antenna was fabricatred such that it could be attached to the surface of styrofoam(ε_r=1.06, t=10 mm) having a size of 10 mm × 9 mm × 10 mm (0.05 λ × 0.05 λ × 0.05 λ). The thickness and length of the feeding line and the spacing between short stubs were adjusted for impedance matching. S₁₁ was found to be -18.8 dB at the center frequency of the fabricated antenna, 1.575 GHz. The radiation pattern measurement results show that the maximum gain of E_θ is 1.87 dBi in 0 directions in the xz-plane, and that E_θ is an omnidirectional characteristic with an average gain of -1.7 dBi in the yz-plane. It was found that the antenna can be used as an ultra-small microstrip antenna, which can be mounted on a small dron for GPS, and is capable of preserving a reduction ratio of 98.8% as compared to a λ/2 microstrip patch antenna.

• Horticultural Science & Technology
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• v.33 no.3
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• pp.303-308
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• 2015

The consumption of leaf vegetables has been steadily increasing in Korea. Leaf vegetables are used for "Ssam (vegetable wrap-up), eaf vegetables has been steadily increasing in Korea. Leaf vegetables are used for asoned condiments inside several layers of young vegetable leaves. This study investigated the effect of air temperature on the growth and phytochemical contents of beet (Beta vulgaris L.) and Ssamchoo (Brassica lee L. ssp. namai) grown in a closed-type plant factory system where fluorescent lamps were used as an artificial light source. Seeds of beet and Ssamchoo were sown in a peat-lite germination mix. The roots of 20-day-old seedlings were washed, and the seedlings were planted on a styrofoam board and grown in hydroponic beds for 25 days under fluorescent light. Plants were exposed to one of three different air temperature regimes (20, 25 and $30^{\circ}C$ during the day combined with $18^{\circ}C$ during the night), which were monitored with a sensor at 30 cm above the plant canopy. Increased plant height and leaf area were observed in beet at $25^{\circ}C$ and $30^{\circ}C$ compared to $20^{\circ}C$. For Ssamchoo, the greatest plant height, leaf area, fresh weight and dry weight were obtained at $20^{\circ}C$. Ascorbic acid content of beet and Ssamchoo leaves were highest at $30^{\circ}C$. In beet, total polyphenol and flavonoid contents were higher at $20^{\circ}C$ (42.4, $197.0mg{\cdot}g^{-1}DW$) and $25^{\circ}C$ (46.9, $217.0mg{\cdot}g^{-1}DW$) than $30^{\circ}C$ (22.4, $88.0mg{\cdot}g^{-1}DW$). In Ssamchoo, total polyphenol and flavonoid contents were also higher at $20^{\circ}C$ (79.2, $268.2mg{\cdot}g^{-1}DW$) and $25^{\circ}C$ (66.3, $258.3mg{\cdot}g^{-1}DW$), respectively, than $30^{\circ}C$ (53.7, $134.7mg{\cdot}g^{-1}DW$). Hence, the optimum temperature appears to be $20^{\circ}C$ for growing both beet and Ssamchoo in a closed-type plant factory system with fluorescent light.

• Journal of Bio-Environment Control
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• v.20 no.2
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• pp.116-122
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• 2011

This study was carried out to investigate the effects of several cooling methods such as water hose cooling, mist, fog and control on growth and microclimate, and to develop a simple nutriculture bed for production of fresh leaves of narrowhead goldenaray 'Ligularia stenocephala'. When the root-zone was cooled with 240 L/hr flow rate of $13^{\circ}C$ ground water using water hose, the temperature was lowered approximately by 2 to $3^{\circ}C$ than that of control. The growth of narrowhead goldenaray were favorable in the water hose cooling compared with the other cooling methods. Nutrient culture system having part cooling effect around plant canopy was developed. The system was composed of 15 cm diameter of water hose on side wall of beds, cooling hose, and expanded rice hull media as organic substrate. When cool water which the temperature changed in the range of 14 to $22^{\circ}C$ diurnally with 240 L/hr of flow rate through water hose, the air temperature around canopy and root-zone temperature were dropped by $0.5^{\circ}C$ and $3^{\circ}C$ compared with that of conventional styrofoam bed, respectively. These results showed that newly devised bed system using water hose was simple and economical for the production of high quality narrowhead goldenaray leaves. This system might be practically used both at summer and winter season for the cultivation of narrow head goldenaray by part cooling or heating around root-zone and plant canopy.