• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.2
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• pp.230-237
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• 2003

For hygenic evaluation, microbiological tests of seasoned raw vegetal)les from five high school foodservice operations were conducted. The antimicrobiological effect of pre-preparation with vinegar against microorganisms on vegetables in foodservice operations was also investigated. Total plate counts of leek gukgalli, broad bellflower saengchae and vegetable salad ranged from 10$^4$ CFU/g to 10$^{6}$ CFU/g. Coliform levels of those ranged from 10$^2$CFU/g to 10$^4$ CFU/g. Leek washed three times was pre-prepared at different concentration (0.05%,0.1%,0.5%,1% and 2%) and temperature ( 1$0^{\circ}C$ 2$0^{\circ}C$ and 4$0^{\circ}C$) for 5, 10 and 30 minutes. The higher the concentration and temperature of vinegar were, the more the antimicrobiological activity increased. The sanitizing activity of vinegar increased with treatment time. Considering the quality of vegetable and the expense, when the levels of total plate counts and coliform of vegetable were 10$^{6}$ and 10$^3$ CFU/g, pre-preparation with 0.5% of vinegar at 2$0^{\circ}C$ for 10 minutes was best. The population of total plate count and coliform on row and leek washed three times increased during storage for 72 hours. However, The levels of microorganism on leek samples pre-prepared with 0.5% and 1% vinegar decreased during storage. After the treatment of vinegar at 1$0^{\circ}C$ for 10 minutes, Staphylocucus aureus, Escherichia coli O157, Shigella sonnei, Salmonella entritidis, Listeria monolytogenes were not detected.

• Korean Journal of Environment and Ecology
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• v.32 no.1
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• pp.30-38
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• 2018

The purpose of this paper is to provide reference data about propagation, restoration, and preparation of policy of endangered Sarcandra glabra (Thunb.) Nakai by investigating growth response and variation of ecological niche breadth according to moisture and nutrient under the condition of elevated $CO_2$ concentration and elevated temperature. We divided the investigation into the controlled group and treated group (elevated $CO_2$ concentration and elevated temperature) and then varied the moisture and nutrient treatment for testing. The results showed that the ecological niche breadth was wide at moisture and nutrient gradients of 0.899 and 0.844, respectively, under control. Also, the ecological niche breadth regarding the moisture and nutrient gradients under treatment simulating global warming was wider as 6.60% and 2.09%, respectively. Therefore, moisture and nutrient will not be the restriction factors concerning the growth of Sarcandra glabra under continued global warming. However, it will be advisable to specify the nutrient content condition in the soil to be 10% for population restoration when growing Sarcandra glabra in the green house which is not affected by external environment since the studies of rearing reaction reported that Sarcandra glabra prefer 10% of nutrient content than 0-5%. Furthermore, it is necessary to protect evergreen broad-leaved forest where is the natural habitat of Sarcandra glabra that has relatively high nutrient content.

• Korean Journal of Environmental Agriculture
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• v.6 no.2
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• pp.39-45
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• 1987

A water culture experiment was conducted to investigate the effect of As content in a culture solution on the water status and growth of rice plants. Rice (Oryza sativa L. Line. Iri 316) seeds were germinated in bentonite and cultivated there for 30 days. Rice seedlings were transplanted into 3.5l pots containing the culture solution on May 1, 1985 and allowed to grow without As treatment for one month. Afterwards, they were grown in a culture solution maintaining the final concentration of As, 0, 1, 5, 10 and 15mg/1 renewing in the solution dissolved sodium arsenate at intervals of 3 to 7 days. Plants were cultivated in the green house during the growing period and harvested 60 days after As treatment. The results obtained were as follows: Transpiration of rice plants was decreased with the increase of the As level in the culture solution. Stomatal diffusive resistance and leaf temperature increased with increase of As levels though the humidity and the air flow rate in leaf decreased. Air flow rate, transpiration and stomatal diffusive resistance showed a highly significant correlation with As contents in shoots and roots of rice plants: Espally The air flow rate and transpiration revealed a significantly higher correlation with As contents in the root than that in the shoot, but diffusive resistance showed adverse tendency. High levels of As in the culture solution depressed plant height, no. of tillers, leaf width and dry weight of plant remarkably. Typical symptoms of As toxicity were root discoloration, and necrosis of leaf tips and margins, and leaf rolling during the sunny daytime were also another symptoms.

• Horticultural Science & Technology
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• v.34 no.3
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• pp.461-471
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• 2016

This study was conducted to establish an in vitro propagation system for sea-milkwort (Glaux maritima L.), which is an endangered coastal plant species with high horticultural value. Two phenotypes, 'Red type (RT)' and 'Pistachio type (PT)' based on the colors of stem and flower, were obtained from a personal horticulturist in 2009 and used for this study as plant materials. The stock plants showed typical morphologies in flower, capsule, and seed appearances as previously reported. Low temperature treatment at $4^{\circ}C$ for four or more weeks after in vitro sowing maximized seed germination percentage, indicating that imbibition of seed and subsequent low temperature treatment are crucial for its germination. The in vitro seedlings had phenotypic variation, falling into 'RT' and 'PT' classes like the stock plants. Although slight differences depending on genotype and medium were recognized, the fourth or fifth nodes detached from the in vitro seedlings revealed the best multiplication efficacy when estimated on the basis of total number of nodes of newly developed axillary shoots. In addition, the nodes from 'RT' and 'PT' regenerated the most shoots on medium supplemented with $0.5mg{\cdot}L^{-1}$ BA alone and $0.5mg{\cdot}L^{-1}$ BA plus $0.5mg{\cdot}L^{-1}$ IAA, respectively. The node culture-derived plantlets were well acclimatized in a culture room ex vitro and completed the pseudo-annual life cycle coincident with that in the natural salt march habitat with the current cultivation method of applying fresh water-irrigation under an inland environment. This work represents the first report of in vitro propagation of sea-milkwort. Thus, our study will contribute to exo-habitat conservation and natural habitat restoration of this endangered species in addition to development of a horticultural product.

• Economic and Environmental Geology
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• v.53 no.6
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• pp.667-675
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• 2020

An Alum-sludge based adsorbent (ASBA) was synthesized by the hydrothermal treatment of alum sludge obtained from settling basin in water treatment plant. ASBA was applied to remove fluoride and arsenic in artificially-contaminated aqueous solutions and mine drainage. The mineralogical crystal structure, composition, and specific surface area of ASBA were identified. The result revealed that ASBA has irregular pores and a specific surface area of 87.25 ㎡ g-1 on its surface, which is advantageous for quick and facile adsorption. The main mineral components of the adsorbent were found to be quartz(SiO2), montmorillonite((Al,Mg)2Si4O10(OH)2·4H2O) and albite(NaAlSi3O8). The effects of pH, reaction time, initial concentration, and temperature on removal of fluoride and arsenic were examined. The results of the experiments showed that, the adsorbed amount of fluoride and arsenic gradually decreased with increasing pH. Based on the results of kinetic and isotherm experiments, the maximum adsorption capacity of fluoride and arsenic were 7.6 and 5.6 mg g-1, respectively. Developed models of fluoride and arsenic were suitable for the Langmuir and Freundlich models. Moreover, As for fluoride and arsenic, the increase rate of adsorption concentration decreased after 8 and 12 hr, respectively, after the start of the reaction. Also, the thermodynamic data showed that the amount of fluoride and arsenic adsorbed onto ASBA increased with increasing temperature from 25℃ to 35℃, indicating that the adsorption was endothermic and non-spontaneous reaction. As a result of regeneration experiments, ASBA can be regenerated by 1N of NaOH. In the actual mine drainage experiment, it was found that it has relatively high removal rates of 77% and 69%. The experimental results show ASBA is effective as an adsorbent for removal fluoride and arsenic from mine drainage, which has a small flow rate and acid/neutral pH environment.

• Economic and Environmental Geology
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• v.54 no.6
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• pp.689-698
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• 2021

Since the mine reclamation scheme was implemented from 2007 in Korea, various remediation programs have been decontaminated the pollution associated with mining and 254 mines were managed to reclamation from 2011 to 2015. However, as the total amount of contaminated mine drainage has been increased due to the discovery of potential hazards and contaminated zone, more efficient and economical treatment technology is required. Therefore, in this study, the adsorption properties of arsenic was evaluated according to the adsorbents which were derived from water treatment sludge(Alum based adsorbent, ABA-500) and granular ferric hydroxide(GFH), already commercialized. The alum sludge and GFH adsorbents consisted of aluminum, silica materials and amorphous iron hydroxide, respectively. The point of zero charge of ABA-500 and GFH were 5.27 and 6.72, respectively. The result of the analysis of BET revealed that the specific surface area of GFH(257 m²·g^-1) was larger than ABA-500(126~136 m²·g^-1) and all the adsorbents were mesoporous materials inferred from N₂ adsorption-desorption isotherm. The adsorption capacity of adsorbents was compared with the batch experiments that were performed at different reaction times, pH, temperature and initial concentrations of arsenic. As a result of kinetic study, it was confirmed that arsenic was adsorbed rapidly in the order of GFH, ABA-500(granule) and ABA-500(3mm). The adsorption kinetics were fitted to the pseudo-second-order kinetic model for all three adsorbents. The amount of adsorbed arsenic was increased with low pH and high temperature regardless of adsorbents. When the adsorbents reacted at different initial concentrations of arsenic in an hour, ABA-500(granule) and GFH could remove the arsenic below the standard of drinking water if the concentration was below 0.2 mg·g^-1 and 1 mg·g^-1, respectively. The results suggested that the ABA-500(granule), a low-cost adsorbent, had the potential to field application at low contaminated mine drainage.

• Economic and Environmental Geology
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• v.55 no.6
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• pp.727-736
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• 2022

Ice wedges are subsurface ice mass structures that formed mainly by freezing precipitation with airborne dust and surrounding soil particles flowed through the active layer into the cracks growing by repeating thermal contractions in the deeper permafrost layer over time. These ice masses characteristically contain high concentrations of solutes and solids. Because of their unique properties and distribution, the possibility of harnessing ice wedges as an alternative archive for reconstructing paleoclimate and paleoenvironment has been recently suggested despite limited studies. It is imperative to preserve the physicochemical properties of the ice wedge (e.g., solute concentration, mineral particles) without any potential alteration to use it as a proxy for reconstructing the paleo-information. Thawing the ice wedge samples is prerequisite for the assessment of their physicochemical properties, during which the paleo-information could be unintentionally altered by any methodological artifact. This study examined the effect of thawing conditions and procedures on the physicochemical properties of solutes and solid particles in ice wedge samples collected from Cyuie, East Siberia. Four different thawing conditions with varying temperatures (4 and 23℃) and oxygen exposures (oxic and anoxic) for the ice wedge sample treatment were examined. Ice wedge samples thawed at 4℃ under anoxic conditions, wherein biological activity and oxidation were kept to a minimum, were set as the standard thawing conditions to which the effects of temperature and oxygen were compared. The results indicate that temperature and oxygen exposure have negligible effects on the physicochemical characteristics of the solid particles. However, the chemical features of the solution (e.g., pH, electric conductivity, alkalinity, and concentration of major cations and trace elements) at 4℃ under oxic conditions were considerably altered, compared to those measured under the standard thawing conditions. This study shows that the thawing condition of ice wedge samples can affect their chemical features and thereby the geochemical information therein for the reconstruction of the paleoclimate and/or paleoenvironment.

• Journal of The Korean Society of Grassland and Forage Science
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• v.23 no.4
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• pp.247-254
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• 2003

A study was carried to compare two varieties of tall fescue(Festuca arundinacea Schr.): Fawn (endophyte infection) and Roa(endophyte-free). The study examined plant height, botanical composition, and dry matter yield of mixed pasture. The cattle grazed on a mixed pasture of tall fescue species and orchardgrass(Dactylis glomerata L.), perennial ryegrass(Lolium perenne L.) and white clover(Trifolium repens L.) during March 22, 1997, to September 21, 1997. The number of grazing animals was 4.3/ paddock(50m x50m) and was adjusted according to the condition of pasture. Dry matter yields determined on ungrazed pasture(7-time harvests) were 1,690 $\pm$407kg and 1,128 $\pm$ 238kg/ha on pastures consisting of Fawn and Roa, respectively. This difference was significant(P<0.01). There were 17.71 $\pm$ 1.27cm and 12.83$\pm$0.90cm in average plant lengths of Fawn and Roa(P<0.01), respectively The botanical composition of tall fescue and orchardgrass in the mixture treatment included in the Fawn variety were shown in 34.2 and 3.8％, comparing Roa with 17.1 and 9.6％, on the 21th of September, 1997, respectively. Tall fescue Roa represented a higher botanical composition than orchardgrass(a main species on Cheju). Crude protein content of Fawn was slightly less than that of Roa. From these results, we may conclude that Roa variety is nutritionally better, but is less adaptible to high temperature climate than Fawn. However, Roa variety is still better than orchardgrass in high temperature conditions.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.64 no.3
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• pp.165-175
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• 2019

In response to elevated temperature, a shift in the rice planting period was proposed as a promising option in temperate regions. To understand the yield response of early maturing rice to different transplanting dates and to analyze the related agronomic traits in the central plain area, we performed a two-year study using different transplanting dates and six varieties in Suwon, Korea. The maximum head rice weight was achieved in the treatments transplanted between June 14 and 29, depending upon the varieties. The optimal mean temperature during the 40 days from heading stage for attaining the maximum head rice weight was $21.8^{\circ}C$ on the average of six varieties. The index of head rice weight was positively correlated with the indices of both the milled rice weight and head rice percentage, the latter showing a higher coefficient of determination. The highest milled rice weight was commonly achieved from the treatment transplanted on June 29, where the head rice weight was also the highest. The index of milled rice weight was significantly correlated with the indices of grain filling percentage and number of spikelets per area, but not correlated with the index of 1000-brown rice weight. The transplanting date with the highest milled rice yield produced the largest number of spikelets per area, greatest biomass at the heading and harvesting stages, and highest level of harvest index. We suggest that the optimal transplanting date for early maturing rice varieties in the central plain area is from June 14 to 29. High head rice yield in this study was attributed to increased spikelets owing to the increased biomass production at the heading stage, enhanced grain filling due to the high biomass production and harvest index at maturity, and improved head rice percentage.

• Journal of the East Asian Society of Dietary Life
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• v.21 no.6
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• pp.853-862
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• 2011

We reproduced and investigated the quality characteristics of Samhaeju (one type of Korean traditional rice wine), which has been described in ancient documents. During fermentation, the room temperature was $9.1{\sim}25.0{\circ}C$, and each treatment's material temperature was $11.7{\sim}23^{\circ}C$. As the fermentation proceeded, the pH rapidly decreased (initial pH was 6.6~6.9) and rose gradually from the 18th day. Titratable acidity and amino acidity slowly increased in general. Regarding soluble solid contents, there were various change patterns depending on the production method, and they were affected by initial room temperature. In the treatments using 1 (Sang-ga-yo-rok), 3 (Eum-sik-di-mi-bang), 7 (Jo-sun-mu-ssang-sin-sik-yo-ri-je-beop), 8 (Sang-ga-yo-rok $15^{\circ}C$), reducing sugar contents decreased rapidly after 1st mashing day and then increased slightly after 2nd mashing. The alcohol content increased as the fermentation proceeded, and most of the treatments produced 1/2 the amount of total alcohol content before the 2nd mashing day, followed by a slight increase until the end of fermentation (about 100 days from the 2nd mashing day). In the sensory evaluation, Samhaeju using methods 2, 4, 5, and 6 got high scores and had much reducing sugar contents than other treatments. Among the seven manufacturing processes, method 2 was relatively simple and got the highest score in the sensory evaluation. Therefore, method 2 would be suitable for industrialization and popularization of Korean traditional alcoholic beverage.