• Korean Journal of Soil Science and Fertilizer
• /
• v.24 no.2
• /
• pp.109-115
• /
• 1991

This study examines the effect of submergence on phosphorus adsorption characteristics in Gangseo(paddy soil), Yesan(non-cultivated soil), and Jungdong soil(upland soil). The soils were submerged with glucose sol'n at $28^{\circ}C$ for 17 days. After the submergence, the phosphorus adsorption was conducted at three temperatures(5, 25 and $45^{\circ}C$). The phosphorus adsorption maximum($X_m$) and the equilibrium constant(K) were obtained by Langmuir adsorption isotherm, and the heat of adsorption(${\Delta}H$) was calculated by van't Hoff's equiation. Results obtained are as follows ; 1. The amounts of adsorbed P were increased with temperature, but the effects of temperature on rate of P adsorption were very small in all three soils. 2. By submergence, $X_m$ were increased from 500mg P/kg to 850mg P/kg in Gangseo soil, from 1,850mg P/kg to 3,300mg P/kg in Yesan soil, and from 310mg P/kg to 670mg P/kg in Jungdong soil. But the effects of temperature on $X_m$ were very small in all three soils. 3. Submergence decreased K for Gangseo and Yesan soils, but increased for Jungdong soil. Whereas K were increased with temperature in all three soils. 4. By submergence, ${\Delta}H$ for Gangseo soil was greatly increased (from 2.2 Kcal/mole to 3.5 Kcal/mole), whereas that for Yesan soil changed little (from 5.7 Kcal/mole to 5.5 Kcal/mole). It was 4.4 Kcal/mole in submerged Jungdong soil.

• Journal of Food Hygiene and Safety
• /
• v.32 no.6
• /
• pp.485-492
• /
• 2017

This study investigated to determine the microbial contamination levels of strawberries at harvest and distribution stages and to suggest a control measure for reducing the microbial contamination of strawberries by replacing worker's gloves used at harvest and distribution stages. According to the monitoring results, the contamination levels of total aerobic bacteria (TAB) were in the order of soil ($7.12{\pm}0.61{\log}_{10}CFU/g$), gloves ($6.06{\pm}1.80{\log}_{10}CFU/cm^2$), strawberry ($3.28{\times}0.98{\log}_{10}CFU/g$), and water ($3.08{\pm}0.55{\log}_{10}CFU/g$) at harvest stage. TAB of strawberry at was harvest stage reduced from $3.28{\pm}0.98{\log}_{10}CFU/g$ to $1.85{\pm}0.21{\log}_{10}CFU/g$ and $2.6{\pm}0.30{\log}_{10}CFU/g$ at cold and room temperature storage, respectively. By the replacement of worker's gloves and distribution temperature, TAB levels of the strawberries were significantly reduced when compared to those of the strawberries treated without replacement of worker's gloves and distributed at room temperature. For reusing the replaced gloves, washing with a commercial disinfectant, clorox, was effective to reduce microorganisms contaminated on the worker's gloves. These results demonstrated that appropriate replacement of gloves at the harvest and distribution stages is an effective method for reducing microbial contamination of fresh strawberries.

• The Journal of Korean Academy of Prosthodontics
• /
• v.53 no.3
• /
• pp.189-197
• /
• 2015

Purpose: The aim of this study was to assess the degree of awareness and actual practice of dental practitioners regarding infection control during prosthodontic treatment. Materials and methods: Study participants were composed of dentists, dental hygienists, dental technicians working at dental university hospital, general hospital, dental hospital and dental clinics in Daejeon, Korea (n=126). The questionnaires included the data on general characteristics, education, awareness and practice of infection control procedures during prosthodontic treatment through personal self-administration survey. Awareness and practice were measured by Likert scale ranging from 1 to 5. Statistical analysis was done by one-way ANOVA. Influence of awareness on practice was estimated by regression analysis. Results: 27.7% of the respondents answered that the infection control education regarding prosthodontic treatment is insufficient. The mean value of awareness and practice of infection control during the prosthodontic treatment were $2.72{\pm}0.80$, $1.58{\pm}0.88$, respectively. The mean value of practice who answered that had education curriculum at college was $1.62{\pm}0.9$, and $1.31{\pm}0.49$ who did not. The mean value of awareness who equipped guideline was $3.01{\pm}0.9$, and $2.56{\pm}0.70$ who did not. Conclusion: 1. The respondents who received the infection control education by college curriculum showed higher degree of practice than the respondents who did not. 2. The respondents who have appropriate infection control guidebook in their workplace showed higher degree of awareness than the respondents who did not. 3. There was a correlation between the awareness and practice of infection control during prosthodontic treatment; the degree of awareness becomes higher, so does the degree of practice. 4. During the prosthodontic treatment, the degree of practice was lower than the degree of awareness on infection control.

• Journal of Korean Society of Transportation
• /
• v.33 no.4
• /
• pp.379-392
• /
• 2015

Freight flow data in Korea has been collected for a variety of purposes by various organizations. However, since the representation and format of the data varies, it has not been substantially used for freight analyses and furthermore for freight policies. In order to increase the applicability of those data sets, it is required to bring them in a table and compare for finding the differences. Then, it is shown that the raw data can be aggregated by a particular criterion such as mode, origin and destination, and type commodity. This study aims to examine the freight data issue in terms of three different points of view. First, we investigated various freight volume data sets which are released by several organizations. Second, we tried to develop formulations for freight volume data. Third, we discussed how to apply the formulations to network models in which particular OR (Operations Research) techniques are used. The results emphasized that some data might be useless for modeling once they are aggregated. As a result of examining the freight volume data, this study found that 14 organizations share their data sets at various aggregation levels. This study is not an ordinary research article, which normally includes data analysis, because it seems to be impossible to conduct extensive case studies. The reason is that the data dealt in this study are diverse. Nevertheless, this study might guide the research direction in the freight transport research society in terms of data issue. Especially, it can be concluded that this study is a timely research because the governmemt has emphasized the importance of sharing data to public throughout 'government 3.0' for research purpose.

• Korean Journal of Soil Science and Fertilizer
• /
• v.45 no.3
• /
• pp.435-443
• /
• 2012

This study investigated soil carbon storage and microbial activities influenced by different management practices in rice paddies and pastures. Soils under a single-crop farming of rice (CON) and rice-Italian ryegrass rotation farming (IRG) were compared in Jangheung, Jeollanam-do, Seocheon and Cheonan, Chungcheongnam-do. Soils from pastures were analyzed to investigate the effect of duration period (P1, P2, P3) in Namwon, Jeollabuk-do and Seosan, Chungcheongnam-do. In rice paddy, total and particulate carbon (PC) concentrations in the IRG soils were significantly higher than those in the CON soils both in Jangheung and Seocheon where the IRG has been established for three years, whereas carbon concentrations were not significantly different in Cheonan where IRG planting history is only one year. In rice paddy soils, PC was suggested as an early indicator to monitor changes in soil carbon storage followed by adopting different management practices. In pasture, total and PC concentrations increased with duration period especially in the 0-5 cm soils. Contrary to the rice paddy soils, the magnitude of change in PC concentration is not as great as that in total carbon concentration, implying that there is a need to develop a new early indicator other than PC using different fractionation scheme. The soil carbon storage in pasture also increased with years since establishment and the increasing rate was significantly greater in the early stage (0-5 yrs) than the later one (> 5 yrs). Microbial activities measured from fluorescein diacetate (FDA) hydrolysis analysis were significantly lower in the IRG soils than CON soils, whereas no difference was observed in the pastures of different ages. This shows that FDA activity is not a sensitive indicator to differentiate soil qualities influenced by management practices if it is used by itself.

• Korean Journal of Microbiology
• /
• v.55 no.3
• /
• pp.289-292
• /
• 2019

Lachnospiraceae bacterium KGMB03038 (=KCTC 15821) belonging to the class Clostridia in phylum Firmicutes, was isolated from a stool sample of a healthy Korean. Herein, we report the complete genome sequence of strain KGMB03038 analyzed using the PacBio Sequel platform. The genome comprises of 3,334,474 bp with G + C content of 47.8%, which includes 3,099 predicted protein-coding genes, 12 ribosomal RNAs, 54 transfer RNAs, and 4 ncRNAs. Genome analysis revealed that strain KGMB03038 possesses a number of genes involved in hydrolysis of carbohydrates, including mono-, di-, and oligo-saccharides, and biosynthesis of various amino acids.

• Journal of Food Hygiene and Safety
• /
• v.36 no.6
• /
• pp.493-503
• /
• 2021

The study was designed to analyze raw and auxiliary materials of Korean traditional cookies such as Yugwa and Gangjeong, equipment and tools, personal hygiene of workers and microbial contamination of materials by each manufacturing process. In addition, it looked at washing method for reducing microorganisms at the site and reduction effect of microorganisms by frequency in the manufacturing processes of Yugwa. In the process of producing Korean traditional cookies, the level of total aerobic bacteria (TAB) in popped rice was 1.2 Log CFU/g and the level of TAB in finished products increased to 3.7 Log CFU/g. In the process of producing Yugwa, the level of TAB increased to a maximum of 6.5 Log CFU/g in the soaking process but decreased to 1.3 Log CFU/g in the frying process. However, the level of TAB increased again to 1.3 Log CFU/g in finished products that proves its recontamination. It is estimated that he manufacturing process causes cross-contamination that comes from the work tools, equipment or workers. In particular, the spatula, one of the work tools, was found to have 4.4 Log CFU/g of aerobic bacteria and 4.2 Log CFU/g of colon bacillus that show they are highly contaminated. In the soaking process of Yugwa that lasts seven days, the level of TAB was a maximum of 10 Log CFU/g and the level of total colon bacillus was 6.8 Log CFU/g. When compared with washing methods, using hands and tools or running water, it is confirmed that the level of both TAB and total colon bacillus decreased to 5.0 Log CFU/g and 2.8 Log CFU/g respectively when hands were washed with running water 10 times. The above result shows that it's required for workers to wash their hands as well as wash and disinfect work tools and equipment in the process of producing Korean traditional cookies at small-scale companies. In addition, to reduce the level of microbial contamination in finished products, workers are required to apply their reduction method at the site.

• Korean Journal of Plant Resources
• /
• v.36 no.2
• /
• pp.107-121
• /
• 2023

This study analyzed the polyphenol, flavonoid contents, antioxidant activity, anti-aging activity and phenol component contents of Saccharina japonica (SJ), Costaria costata (CC) extracts with hot water, 95% methanol, 95% prethanol for investigating possible utilization of SJ and CC extracts. The result revealed that the SJ and CC methanol extracts showed the highest polyphenol and flavonoid contents, 4.63 mg TAN/g, and 4.19 mg QUE/g respectively. Also, the SJ and CC methanol extracts showed higher antioxidant activity than prethanol and hot water extracts, whereas the ABTS radical scavenging activities were the highest in prethanol extracts (IC₅₀ = 15.4, 10.3 ㎍/µL). In anti-aging activity for evaluating the anti-wrinkle activity and skin whitening activity, the CC methanol extracts had high collagenase inhibitory activity (88.3%), and the SJ prethanol extracts showed higher elastase inhibitory activity (19.0%) compared to other extracts. Then the tyrosinase inhibitory activity was significantly higher in the SJ and CC methanol extracts (41.8, 30.3%, respectively), whereas prethanol extracts were the lowest. To identify the phenol component contents of SJ and CC extracts, 4-hydroxybenzoic acid, naringenin, naringin and nicotinic acid were measured using LC-MS/MS. As a result, the phenol contents were the highest in SJ methanol extract (4-hydroxybenzoic acid), SJ and CC prethanol extract (naringin and naringenin) and CC prethanol extract (nicotinic acid). Lastly, the antioxidant activity of SJ and CC showed high correlations with polyphenol and flavonoid contents (R = -0.946~0.883). These results suggest that prethanol or methanol extracts of SJ and CC have higher antioxidant activities, anti-aging activity and the potential to be used as material for health functional food and cosmetics.

• Journal of radiological science and technology
• /
• v.37 no.3
• /
• pp.233-238
• /
• 2014

The amount of environmental radiation was measured in the indoor(basement) and outdoor(rooftop) of the two buildings of the University (the old building and the new building) in Suwon City, Gyeonggi Province. Measuring the environmental radiation dose from the first week of April 2013 to last week of March 2014, Twice a week, one year. The measured results were as follows. 1. The average annual environmental radiation of the two buildings were $0.169727{\mu}Sv/hr$. The lowest value was $0.0760{\mu}Sv/hr$ whereas the highest value was $0.3000{\mu}Sv/hr$. 2. The amount of environmental radiation dose was $0.176373999{\mu}Sv/hr$ in the old building and the amount of environmental radiation dose was $0.163052885{\mu}Sv/hr$ in the new building. The old building environmental radiation dose was higher then the new building. 3. The month of the lowest amount of environmental radiation dose in a year was November resulting in $0.152844{\mu}Sv/hr$ whereas May was found the month of the highest amount of environmental radiation dose showing with $0.197222{\mu}Sv/hr$. 4. The amount of environmental radiation dose in the indoor(basement) was $0.164649{\mu}Sv/hr$ and the amount of environmental radiation dose of the outdoor(rooftop) was $0.174779{\mu}Sv/hr$. And the outdoor(rooftop) was higher than the indoor(basement). 5. Depending on seasonal, the lowest amount of environmental radiation dose was in winter with $0.1632{\mu}Sv/hr$ while spring was the season with the highest amount of environmental radiation dose with $0.183846{\mu}Sv/hr$. The measured amount was high in the order of spring, summer, autumn, and winter.

• Korean Journal of Plant Resources
• /
• v.29 no.2
• /
• pp.241-263
• /
• 2016

This study was carried out to survey the vascular plants on Mt. Seokbyeongsan (1,055 m) and provide a basis for the conservation and management of plant resources. The vascular plants were surveyed from March to October 2015. The flora on Mt. Seokbyeongsan was classified as follows: 102 families, 295 genera, 454 species, 4 subspecies, 51 varieties, 7 forms, and a total of 516 taxa. Endemic plants included 17 families, 24 genera, 25 species, 1 variety, and a total of 26 taxa. The Korea Forest Service assignment of rare plants, including 21 families, 33 genera, 33 species, 3 varieties, and a total of 36 taxa, was investigated. Moreover, the Ministry of Environment assignment of rare plants, including 13 families, 17 genera, 17 species, 1 variety, and a total of 18 taxa, was investigated. Floristic special plants in the surveyed area were divided into five classes (Classes I-V): 42 taxa of Class I, 26 taxa of Class II, 35 taxa of Class III, 20 taxa of Class IV, and 9 taxa of Class V for a total of 132 taxa. Naturalized plants were 18 taxa, and plants threatened by climate change were 48 taxa.