• Journal of the Korean Wood Science and Technology
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• v.36 no.6
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• pp.113-120
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• 2008

This study was performed to develop environmentally-friendly finishing materials for construction. In order to abate formaldehyde and ammonia in indoor air, liquid coating agents for indoor finishing were formulated with bamboo charcoal powder, cypress extracted water, and water-borne acrylic binder. Deodorization rate, far-infrared ray emission rate, anions emission amount, and anti-bacterial effect were investigated. Deodorization rate was increased as cypress extracted water content increased. Deodorization rates of the coating agents were 60.0~98.6% on formaldehyde and 76.7~86.2% on ammonia. No differences on far-infrared ray emission rate, anions emission amount, and anti-bacterial effect were found depending on different formulations. A 91.7% of far-infrared ray emission rate, 77 ea/cc of anions emission amount, and 99.4% of anti-bacterial effect were detected for all formulations. More effective application method of the coating agents revealed was a spray-gun. A $0.66kg/m^2$ of coating agent with a spray-gun and $0.94kg/m^2$ of coating agent with a brush was consumed each.

• Journal of Food Hygiene and Safety
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• v.32 no.1
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• pp.50-56
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• 2017

The purpose of this study was to investigate the microbiological contamination of water and drinking cups in springs and to estimate the toxin gene, enterotoxin production ability and antibiotic susceptibility of foodborne pathogens. Ten spring water and 34 drinking cups were tested. The average number of total aerobic bacteria and coliform bacteria in spring water were 1.8 log CFU/mL and 1.2 log CFU/mL, and in drinking cups were $4.7log\;CFU/100cm^2$ and $1.7log\;CFU/100cm^2$. Salmonella spp., Staphylococcus aureus, E. coli O157:H7, Listeria monocytogenes, Vibrio parahaemolyticus, Yersinia enterocolitica were not isolated from all of samples but Bacillus cereus was detected in 5 (14.7%) of 34 drinking cups. The nheA and entFM genes were major enterotoxin genes in B. cereus isolated from drinking cups. All of B. cereus tested in this study produce non-heamolytic enterotoxin but only 2 isolates possessed heamolysin BL enterotoxin producing ability. B. cereus was resistant to ${\beta}-lactam$ antibiotics. These results revealed that the sanitary conditions of drinking cups in spring should be improved promptly. The substitution carrying a personal drinking cup for the public drinking cups equipped in springs is suggested to prevent food-borne illness.

• Korean Journal of Agricultural and Forest Meteorology
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• v.9 no.1
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• pp.61-70
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• 2007

This study was conducted to investigate nutrient dynamics and water quantity of throughfall and stemflow in natural oak stands in Korea. The ratio of the total throughfnll and stemflow to the amount of precipitation varied with locations. It was considered that the ratio was affected not only by the characteristics of tree species but also by regional, weather and other environmental conditions. It was, therefore, necessary to set up a water control system to launch a tending project for natural oak stands. Comparisons of nutrient amount in throughfall among regions reflected regional characteristics. $Ca^{2+},\;Mg^{2+}$ and $K^+$ ions were leached from the canopy and yellow sand accumulation. $Na^+$ and $Cl^-$ were marine-borne. $NO_3^-$ and $SO_4^{2-}$ resulted from dry deposition of air pollutants. Nutrient amount in the stemflow was as low as about 10% of that in the total throughfall and stemflow. The pH of stemflow in natural oak stands in urban areas ranged from 3 to 5. Influx of the acidic stemflow to soil could, in the long term, affect pH in soil solution and nutrient dynamics around root zones.

• Journal of Korea Water Resources Association
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• v.39 no.10 s.171
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• pp.823-832
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• 2006

Precipitation is the most important component to the study of water and energy cycle in hydrology. In this study we investigate rainfall retrieval uncertainty from different sources of remotely sensed precipitation field and then probable error propagation in the simulation of hydrologic variables especially, runoff on different vegetation cover. Two remotely sensed rainfall retrievals (space-borne IR-only and ground radar rainfall) are explored and compared visually and statistically. Then, an offline Community Land Model (CLM) is forced with in situ meteorological data to simulate the amount of runoff and determine their impact on model predictions. A fundamental assumption made in this study is that CLM can adequately represent the physical land surface processes. Results show there are big differences between different sources of precipitation fields in terms of the magnitude and temporal variability. The study provides some intuitions on the uncertainty of hydrologic prediction via the interaction between the land surface and near atmosphere fluxes in the modelling approach. Eventually it will contribute to the understanding of water resources redistribution to the climate change in Korean Peninsula.

• Korean Journal of Food Science and Technology
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• v.37 no.1
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• pp.113-121
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• 2005

Antimicrobial effects of Camellia japonica L. were determined against Escherichia coli, Salmonella typhimurium, Staphylococcus aureus, and Listeria monocytogenes using paper disc method, and minimum inhibitory concentrations (MICs) were measured. Methanol extract (MEex), water fraction (WAfr), and butanol fraction(BUfr) showed antimicrobial effects against all tested microorganisms, with MEex showing strong antimicrobial effect against S. aureus and L. monocytogenes, and WAfr, Bufr, and ethylacetate fraction (EAfr)against S. aureus. No effects were observed in n-hexane fraction (HEfr) and chloroform fraction (CHfr) against all tested microorganisms. All species grown in the medium adding fractions of Camellia Japonica L. leaves extact were inhibited from WAfr and BUfr, repectively.(meaning not clear) MEex showed over 25% inhibitory effect against all tested microorganisms. BUfr showed over 50% inhibitory effect against all microorganisms except L. monocytogenes. EAfr and WAfr showed over 30% effect against S. aureus and L. monocytogenes. MICs of MEex against S. typhimurium and BUfr against S. aureus were 625 g/mL, indicating C. japonica L. extract can exert antimicrobial activity even at low concentration.

• Journal of Korean Society on Water Environment
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• v.35 no.3
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• pp.224-233
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• 2019

Nitrogen components in liquid manure can reduce safety and quality of environment harmfully. To minimize the environmental risks of manure, understanding fate of manure in environment is necessary. This study aimed at investigating applicability of a simplified Level III fugacity model for simulating $NH_3-N$ component to analyze environmental fate and transport of $NH_3-N$ in liquid manure and to provide basis for improving management of N in the liquid manure system and for minimizing the environmental impacts of N. The model simulation conducted for four environmental compartments (air, water, soil, and rice plants) during rice-cropping to trace $NH_3-N$ component and provided applicability of the Level III fugacity model in studying the environmental fate of $NH_3-N$ in manure. Most of $NH_3-N$ was found in water body and in rice plants depending upon the physicochemical properties and proper removal processes. For more precise model results, the model is needed to modify with the detailed removal processes in each compartment and to collect proper and accurate information for input parameters. Further study should be about simulations of various N-typed fertilizers to compare with the liquid manure based on a modified and relatively simplified Level III fugacity model.

• Journal of Food Hygiene and Safety
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• v.28 no.3
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• pp.279-285
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• 2013

To establish sample preparation method for detection of food-borne pathogens from lettuce, perilla leaves, cucumber, pepper, and cherry tomato, the influences of diluent composition, processing time, and proportion of diluent to sample were examined. Each produce was inoculated with 6.0 log $CFU/cm^2$ of Escherichia coli O157:H7, Salmonella Typhimurium, Listeria monocytogenes, Staphylococcus aureus, and Bacillus cereus. Each produce was treated with 0.1% peptone water, and D/E neutralizing broth. Processing time of produce was 30, 60, 90, and 120s, and the proportion of diluent to sample was 2 : 1, 4 : 1, 9 : 1, and 19 : 1. The number of bacteria after treatment of D/E neutralizing broth was higher than that of 0.1% peptone water (P<0.05). In cherry tomato, the population of S. typhimurium recovered from treated with D/E broth was higher than that recovered from treated with 0.1% peptone water by 1.05 log $CFU/cm^2$ (P<0.05). No difference in numbers of pathogens was observed in processing time. Optimum proportion of diluent to perilla leaf, iceberg lettuce, cucumber, green pepper, and tomato was 9 : 1, 4 : 1, 2 : 1, 2 : 1, and 2 : 1, respectively. These data suggest that D/E neutralizing broth should be recommend as diluent, and the diluent volume applied to produce should be determined in proportion to produce surface area per weight (g).

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.2
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• pp.242-249
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• 2015

This study examined the antioxidant and antimicrobial activities of 70% ethanol extracts and water extracts of Allium hookeri root. We evaluated the effects of water extracts of A. hookeri root on storage of seasoned pork added with water extracts at $4^{\circ}C$ for 21 days in order to evaluate its potential as a functional food material. A. hookeri root water extracts displayed antioxidant activities (total polyphenol content and DPPH and ABTS radical scavenging activities) that were superior to those of 70% ethanol extracts. The 70% ethanol extracts and water extracts of A. hookeri root showed antimicrobial activities against food-borne Staphylococcus aureus bacteria that were about 1/400 times greater than that of vancomycin. Chemical composition analysis was conducted on pork seasoned with sauce containing 5%, 10%, and 15% water extracts. Moisture and crude ash contents significantly decreased as the amount of water extracts increased (P<0.05), and the highest crude protein content was in the 10% group. Acidity of seasoned pork increased proportionally in the early stages of storage, whereas it significantly decreased as the amount of water extracts increased after day 12 (P<0.05). Although the total number of bacteria in seasoned pork continuously increased during storage, growth of bacteria was significantly restricted as level of A. hookeri root water extracts increased (P<0.05). In the sensory evaluation, pork seasoned with 10% A. hookeri root water extracts showed the highest scores for taste, texture, and overall acceptance (P<0.05). In summary, A. hookeri water extracts display antioxidant and antimicrobial activities that can improve quality characteristics of seasoned pork and have potential as natural preservatives to restrict bacteria growth. Regarding the amount of extracts, 10% was determined to be the most appropriate level to minimize changes in seasoned pork during storage and improve sensory quality.

• Journal of agricultural medicine and community health
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• v.9 no.1
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• pp.56-66
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• 1984

Giardia lamblia is a pathogenic flagellate causing intestinal disorders such as diarrhea, abdominal pain and malabsorption of nutrients. Giardia is mainly infected by the ingestion of contaminated foods per os. Craun (1979) has recently reported that mass infection of this flagellate through the contaminated water supply systems is one of public health hazards. Also, so-called traveller's diarrhea is sometimes caused by Giardia infection (CDC, U.S.A., 1971). However, a few epidemiological studies figuring out the mode of infection or control measures of Giardia infection has been done so far in Korea. The present study was aimed to know the prevalence of Giardia infection in several Korean populations, detectability of this flagellate in water systems and the viability of the cysts against sewages and disinfectants applying to drinking water. In the present study, 388 stool specimens from orphanage children in Chun-joo, Chung-joo, On-yang and Chun-an areas and 538 stool specimens from inhabitants in Woo-do, In-chon, and Chun-joo were examined by formalin-ether concentration technique to detect out Giardia cysts. On the other hand, water samples from 14 sites of Han River and its tributaries were collected in May through July, 1984. Fifty liter of water sample in each sampling site was then filtered through water filtering system deviced by U.S. Environmental Proutection Agency and the sediments rinsed out from the thread rolls, a part of water filtering system, were examined to detect out the Giardia cysts. In order to observe the viability of Giardia cysts in the sewage samples, the cysts were treated in it at $4^{\circ}C$ or $25^{\circ}C$ for 7 through 28 days. For this purpose, the cysts were also exposed to various concentrations of disinfectants such as chlorine, iodine and ozone gas for proper time intervals. After treatment, the viability test of the Giardia cysts were carried out by method of Rice and Schaefer (1981) with minor modification. The results obtained in this study were as follows : 1) The detection rates of G lamblia cysts in the stool specimens were 18.3% in orphans and 4.3% in general examinees. 2) The prevalences of Giardia Infection were higher in the young age groups than in-adults. The highest positive rate was 18.4% in the age group less than 10. 3) Of 14 water specimens sampled from Han River system and its tributaries around the Seoul area, the Giardia cysts were detected from 4 samples, and no cyst was found in the water supply systems. 4) The cysts treated in the sewage survived for 28 days at $4^{\circ}C$ and for 13 days at $25^{\circ}C$. 5) The cysts were completely destroyed within 60 minutes by exposure to 8 mg/l of residual chlorine at 4g and within 30 minutes by exposure to the same concentration of chlorine at $25^{\circ}C$. 6) The cysts were all dead when exposed to 1 mg/1 of iodine for 60 minutes at $4^{\circ}C$ or $25^{\circ}C$. 7) The cysts were destroyed after 10 minute exposure in 0.15 mg to 0.25mg of residual ozone gas per liter. Summarizing the above results, it is considered that Giardia infection is regarded as water-borne disease and the cysts are able to be controlled by the application with the disinfectants in the water supply systems.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.7
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• pp.975-979
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• 2010

Biological activities of different parts (stems, leaves, roots, fruits) and solvents (water, ethanol) of seabuckthorn (Hippophae rhamnoides L.) grown in Korea were tested as follows. In the experiment of inhibiting $\alpha$-glucosidase activity, ethanol extract of Hippophae rhamnoides L. stem showed the highest inhibitory activity by 93% and the next highest was the ethanol extract of its leaf by 88.7%. In the case of these two extracts, the effect of inhibiting $\alpha$-glucosidase activity was extraordinarily great when comparing with control group, acarbose. In the experiment of inhibiting $\alpha$-amylase activity, water extract of leaf showed the highest result by 54.7%, among all extracts. Regarding anticancer effect for HT-29 cell and DU-145 cell, water extract of root showed 47.1% and 32.3% activities, respectively. The experiment on antibacterial activity showed that the ethanol extract from the leaf inhibitory activity of Clostridium butyricum, Proteus mirabilis, and Shigella flexneri which are the several food borne pathogenic strains. In future research, materials for biological activity appear isolated and purified and research should continue.