• Journal of Soil and Groundwater Environment
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• v.11 no.6
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• pp.18-27
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• 2006

Air Sparging (IAS, AS) is a ground-water remediation technique, in which organic contaminants are volatilized into air as they rise from saturated to vadose soil zone. This study was conducted to investigate the variation characteristics of TPH, VOCs and $CO_2$ for air sparging of diesel contaminated saturated soil. Initial TPH concentration was 10,000 mg/kg for saturated soil phase and 1,001 mg/L for soil aquifer phase. After 36 days of air sparging, the equilibrium temperature of 2-Dimension experiment system was $24.9{\pm}1.5^{\circ}C$. The saturated soil TPH concentration (in the C10 port close to air diffuser) was reduced to 66.0% of the initial value. The mass amount of $CO_2$ was 3,800 mg and 3,200 mg in air space (C70 port) and in unsaturated soil zone (C50 port), respectively. The VOCs production kinetic parameter was 0.164/day in the air space (C70 port) and 0.182/day in the unsaturated soils (C50 port).

• Journal of Korean Society of Environmental Engineers
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• v.29 no.5
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• pp.564-570
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• 2007

This study investigated the treatment of liquid waste containing highly concentrated iron(III)-ethylenediaminetetraaceticacid (Fe(III)-EDTA) of 70,000 mg/L by an underwater electrical discharge process using low voltage and high current. When AC voltage is applied to the discharging electrode with the other electrode grounded, the temperature of the liquid waste around the discharging electrode rapidly increases, and at the same time, hydrogen and oxygen gases are formed at the electrode as a result of electrochemical reactions. Ultimately, gases formed by vaporization of water and electrochemical reactions cover the electrode. Since the liquid waste is electrically conductive, it elongates the ground electrode up to the border of the gas layer, where electrical discharge occurs. Without hydrogen peroxide, electrical discharge was able to remove about 50% of Fe(III)-EDTA. As the concentration of hydrogen peroxide added increased, the removal efficiency of Fe(III)-EDTA increased. When the molar ratio of hydrogen peroxide to the initial Fe(III)-EDTA was higher than 24.7, more than 80 g of Fe(III)-EDTA was removed with an energy of 1 kWh. A comparison between tungsten and steel electrodes showed that electrode material did not affect the Fe(III)-EDTA removal. In the present underwater electrical discharge process, the removal of Fe(III)-EDTA was completed within 30 min at molar ratios of hydrogen peroxide to the initial Fe(III)-EDTA higher than 24.7.

• Korean journal of applied entomology
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• v.51 no.3
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• pp.235-243
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• 2012

Population dynamics of the American serpentine leafminer, Liriomyza trifolii (Burgess), were observed and modeled in order to compare the effects of air and tomato leaf temperatures inside a greenhouse using DYMEX model builder and simulator (pre-programed module based simulation programs developed by CSIRO, Australia). The DYMEX model simulator consisted of a series of modules with the parameters of temperature dependent development and oviposition models of L. trifolii were incorporated from pre-published data. Leaf surface temperatures of cherry tomato leaves (cv. 'Koko') were monitored according to three tomato plant positions (top, > 1.8 m above the ground level; middle, 0.9 - 1.2 m; bottom, 0.3 - 0.5 m) using an infrared temperature gun. Air temperature was monitored at the same three positions using a self-contained temperature logger. Data sets for the observed air temperature and average leaf surface temperatures were collected (top and bottom surfaces), and incorporated into the DYMEX simulator in order to compare the effects of air and leaf surface temperature on the population dynamics of L. trifolii. The initial population consisted of 50 eggs, which were laid by five female L. trifolii in early June. The number of L. trifolii larvae was counted by visual inspection of the tomato plants in order to verify the performance of DYMEX simulation. The egg, pupa, and adult stage of L. trifolii could not be counted due to its infeasible of visual inspection. A significant positive correlation between the observed and the predicted numbers of larvae was found when the leaf surface temperatures were incorporated into the DYMEX simulation (r = 0.97, p < 0.01), but no significant positive correlation was observed with air temperatures(r = 0.40, p = 0.18). This study demonstrated that the population dynamics of L. trifolii was affected greatly by the leaf temperatures, though to little discernible degree by the air temperatures, and thus the leaf surface temperature should be for a consideration in the management of L. trifolii within cherry tomato greenhouses.

• Research in Plant Disease
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• v.16 no.1
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• pp.59-65
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• 2010

This study was conducted to select the cultivars and strains which are suitable in cultivation of the Chinese cabbage having good horticultural characteristics and the resistance to clubroot caused by Plasmodiophora brassicae, which is a widespread disease that causes serious problems in many Brassica growing areas. Thirty four cultivars and nineteen strains of the Chinese cabbage were planted in the contaminated fields in highland and investigated the wilting symptom due to the initial disease occurrence and high temperature. Disease occurrence rate and severity of clubroot and the horticultural characteristics were also examined. According to the results, Bulamplus, Kangryeokyeoleumbaechu among cultivars of Chinese cabbage, SP-05, SP-02, CR DB 50, and CR DB 29 among strains of Chinese cabbage were resistant to hot weather by showing delayed above-ground symptom (wilting) of clubroot in 30 days after transplanting. In case of below-ground clubroot rate, Daetong, super CR Kimi 85 and super CR Hiroki among the cultivars of Chinese cabbage were resistant to clubroot in 60 days after transplanting. When fresh weight of Chinese cabbage among cultivars were compared, super CR Hiroki of over 2,500 g was the highest among other cultivars. Although the resistant and susceptible reactions of Chinese cabbage cultivars and strains against clubroot disease were somewhat different from the above-ground symptoms (wilting) of clubroot in 30 days and below-ground symptoms of clubroot in 60 days, we recommend that super CR Hiroki, CR Kimi 85, CR Janggun among cultivars of Chinese cabbage and CR DB 50 and CR DB 29 among strains of Chinese cabbage will be more suitable in cultivation of Chinese cabbage in highland.

• Journal of the Korea Organic Resources Recycling Association
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• v.21 no.1
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• pp.69-75
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• 2013

This study is a fundamental research to test the applicability of powdered MSWI(Municipal Solid Waste Incinerator) ash melted slag as a seed Crystal for crystallization reaction. Powdered ash melted slag was melted at $1100^{\circ}C$ and ground to lesser than 0.35mm. According to the result of the tests, calcium, enough for crystallization reaction, was eluted from powdered ash melted slag. Moreover, sample(Phosphorus concentration is under 10 mg/L), more than 90% of Phosphorus can be removed. So we rectify the Phosphorus concentration to 100 mg/L. Alkalinity, being well known that it interferes crystallization reaction, effect was studied for synthetic solution(100 mg/L initial Phosphorus concentration, 50 mg/L calcium, pH 8, 1% powdered ash melted slag dosage). For this result, we know that Phosphorus removal is hindered by alkalinity. In addition, the effect of reaction temperature was performed at the same method. The reaction velocity was increased through raising the reaction temperature.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.10
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• pp.723-730
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• 2011

In this experiment, persulfate, a strong oxidant for ISCO (In-Situ Chemical Oxidation) was used to degraded RDX in artificial ground water at ambient temperature. Results of RDX degradation by persulfate in a batch reactor showed that the oxidation reaction was pseudo first order with estimated Ea (activation energy) of $1.14{\times}10^2kJ/mol$ and the rate was increased with the increase of reaction temperature. The oxidation of RDX by persulfate increased slightly with the increase of initial solution pH from 4 to 8. The RDX oxidation rate increased 13 times at pH 10 compared with that at pH 4, however, alkaline hydrolysis was found to be the main reaction of RDX degradation rather than oxidation. The study also showed that the oxidation rate of RDX by persulfate was linearly dependent upon the molar ratios of persulfate to RDX from 5 : 1 up to 100 : 1, with a proportion constant of $4{\times}10^{-4}$ ($min^{-1}$/molar ratio) at $70^{\circ}C$. While NOM (Natural Organic Matter) exerted negative effects on the oxidation rate of RDX by persulfate, with a proportion constant of $1.21{\times}10^{-4}$ ($min^{-1}{\cdot}L/mg-NOM$) at $70^{\circ}C$ and persulfate/NOM molar ratio of 10/1. The decrease in RDX oxidation rate was linearly dependent upon the added NOM concentration. However, the estimated activation energy in the presence of 20 mg-NOM/L was within 3.3% error compared to that without NOM, which implies the addition of NOM does not alter intrinsic oxidation reaction.

• Korean Journal of Soil Science and Fertilizer
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• v.18 no.1
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• pp.20-26
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• 1985

Under the field condition mulched by polyethylene film, changes of the soil moisture content and soil temperature due to the meteorological influence, which have had a great effect upon productivity of upland - field crop, was investigated. The results obtained were as follows; 1. During the early growth stage from the first part of April to the last part of May, soil temperature at 15cm below the mulched surface of ridge (13:00) was about $5^{\circ}C$ higher than that of non-mulched plot. 20 days earlier than normal soil temperature reached up to $20^{\circ}C$ due to the mulching. The increasing of soil temperature resulted from poly ethylene film mulching had a similar tendency for the annual experiment of 3 years (1982-1984). 2. Changes of the soil moisture content in the plow layer during the growing season was remarkably less in the mulched plot than in the non-mulched plot due to suppression of evaporation by polyethylene film. 3. Soil moisture contents of the plots planted with tobacco was lower than those of the non-planted plots owing to the more transpiration induced by growing of the tobacco plant. As the results, it was refered that initial fresh weight of above ground part of tobacco that had an influence upon the consumption of soil moisture by the transpiration rather than evaporation was about 250g per plant. 4. At the appreciable amount of rainfall (for instance; 63.5mm), soil moisture content at middle place between plants in the plow layer of the mulched plot was not increased owing to the infiltration interruption by polyethylene film. 5. By the comparatively small amount of rainfall (e.g. 20mm) after the drought period, leaf water potential of the mulched plot was not increased as much as that of the non-mulched plot owing to the less moisture content of soil resulted from interruption of rainfall.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.7
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• pp.714-721
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• 2010

This research was undertaken to evaluate the feasibility of lanthanum hydroxide for fluoride removal from aqueous solutions. A batch sorption experiments were conducted to study the influence of various factors such as pH, contact time, initial fluoride concentration and temperature on the sorption of fluoride on lanthanum hydroxide. The optimum fluoride removal was observed in the $pH_{eq}{\leq}8.8$. Sorption equilibrium of fluoride on lanthanum hydroxide was better described by the Freundlish isotherm model than by the Langmuir isotherm model. The adsorption energy obtained from D-R model was 9.21 kJ/mol indicating an ion-exchange process as primary adsorption mechanism. The pseudo-second-order kinetic model described well the experimental kinetic data. Thermodynamic parameters such as ${\Delta}Go^{\circ}$, ${\Delta}H^{\circ}$ and ${\Delta}S^{\circ}$ indicated that the nature of fluoride sorption is spontaneous and endothermic. The used lanthanum hydroxide could be regenerated by washing with NaOH solution. Also, the results applied to real ground water indicate that fluoride selectivity and removal capacity of lanthanum hydroxide were superior to those of PA anion-exchange resin.

• Korean Journal of Agricultural Science
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• v.35 no.2
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• pp.155-165
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• 2008

A seasoned squid Jeotkal, Korean traditional fermented seafood, and its ingredients for manufacturing, including red hot pepper powder, ground garlic, sesame seeds, were irradiated with 0, 0.5, 1, 2, and 5 kGy by electron beam and stored at $4^{\circ}C$ for 4 weeks to determine the changes in microbiological and sensory characteristics. The initial contamination of squid Jeotkal such as total aerobic bacteria, yeast & mold, and coliform bacteria were at the levels of 2.88, 3.04, and 4.20 log CFU/g, respectively. However, electron beam irradiation with does at 5 kGy reduced the total aerobic bacteria to about 1 log CFU/g. Yeast & mold and coliform bacteria were reduced to 1-2 log CFU/g after 2 kGy of irradiation and reached to undetected level when the sample was irradiated at 5 kGy and following storage at $4^{\circ}C$ for 4 weeks. Sensory characteristics showed that electron beam irradiation of up to 5 kGy did not adversely affect overall acceptability of squid Jeotkal and its ingredients during cold storage. Therefore, electron beam irradiation is one of the possible means to improve storage stability of seasoned squid jeotkal, which has limited alternative sterilization methods due to the temperature characteristics of the products.

• Applied Chemistry for Engineering
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• v.34 no.5
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• pp.529-533
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• 2023

The fundamental electrochemical properties and adsorption capabilities of the carbonized product derived from coffee grounds, a prevalent form of lignocellulose abundantly generated in our daily lives, have been extensively investigated. The structure and morphology of the resultant carbonized product, obtained through a carbonization process conducted at a relatively low temperature of 600 ℃, were meticulously examined using a scanning electron microscope. Raman spectroscopy measurements yielded a relative crystallinity (D/G ratio) of the carbon product of 0.64. Electrical measurements revealed a linear ohmic relationship within the carbonized product. Furthermore, the viability of utilizing this carbonized material as an anode in lithium-ion batteries was evaluated through half-cell charge/discharge experiments, demonstrating an initial specific capacity of 520 mAh/g. Additionally, the adsorption performance of the carbon material towards a representative dye molecule was assessed via UV spectroscopy analyses. Supplementary experiments corroborated the material's ability to adsorb a distinct model molecule characterized by differing surface polarity, achieved through surface modification. This article presents pivotal findings that hold substantial implications for forthcoming research endeavors centered around the recycling of lignocellulose waste.