• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.6D
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• pp.557-563
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• 2012

The purpose of this study is to analyze the spatial structure of Mega-Economic Region particularly in Daegu using Freight Origin-Destination (O/D) Data which comes from KTDB. To diagnose the appropriate separation of Regions, the mean of three standardized indices was calculated. The indicates measured are Freight Occupancy Ratio (FOR), Freight Dependancy Ratio (FDR), Scale Parameter (SP), respectively. The result of analysis showed that FOR FDR SP indicators gave effective explanation about characteristic of Regions depending on Freight moving patterns. Especially, Gyeongsan and Gumi had high correlation Regions with FOR FDR indicator. Also, the major industries of Daegu Metropolitan based on the SP indicator are Chemical and Metal machinery industry.

• Korean Journal of Environmental Agriculture
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• v.25 no.4
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• pp.365-370
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• 2006

This study was performed to determine the adsorption-desorption characteristics of polyhexame-thyleneguanidine phosphate in three different soil types of textural classification. Adsorption and desorption studies is impotent for prediction their fate and generating essential information on the mobility of chemicals and their distribution in the soil, water and air of our biosphere. The detection limit of the test substance quantified by a spectroscopic method using Eosin indicator was $0.25{\mu}g/mL$. The reproducibility of analytical method was confirmed by the preliminary test. The concentrations of polyhexamethylenequanidine phosphate in aqueous solution were $1.36{\pm}0.09,\;2.45{\pm}0.01,\;and\;$4.25{\pm}0.05{\mu}g/mL$ by a spectroscopic method using Eosin indicator. The adsorption percents of polyhexamethylenequanidine phosphate in soil were greater than 95.2% for all three test soils. The desorption percents from the adsorbed soil were less than 4.5, 4.7 and 4.7%. Therefore, the adsorption coefficient (K) were greater than 110, 111 and 116. The adsorption coefficient calculated as a function of the organic carbon content (Koc) of the test soils were greater than 9,181, 11,100, and 8,942, respectively. Therefore, the test substance, polyhexamethylenequanidine phosphate could be concluded as medium or high adsorption (>25%) and poorly desorption (<75%) in soil media. Therefore, this chemical is likely to be retained in soil media and may not pose a risk in the aquatic environment.

• The Korean Journal of Food And Nutrition
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• v.19 no.4
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• pp.515-525
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• 2006

Survey was done to total 250 people to analyze characteristics of water quality in 5 widely used mineral water springs-(Teajosan(a), Leechungmukong(b), Onju(c), Yeongin(d), Crown(e))-in Chung-nam area and local mineral water usage. And the content of mineral and physico-chemical properties were compared in 5 sites. The largest users of mineral water spring was $40{\sim}50's$ of ages. Among those mineral water spring users, 52.5% had regular dietary habit and 32% showed improvement in lift habit after using mineral water spring. The mineral water spring users were engaged in student, housewife, professional, self-employed, etc. Those who were highly interested in health were likely to use mineral spring water more often regardless of age and occupation. Five mineral water springs differed in contents of mineral. The average content of minerals was $Ca\;28.5mg/{\ell},\;K\;1.5mg/{\ell},\;Mg\;5.3mg/{\ell},\;Na\;14.3mg/{\ell}$. 'K index' was an indicator of healthy water, and 'O index' was an indicator of tasty water. According to K indek and O index, waters of a b, c and e area were classified as 'tasty and healthy water', and water of e area had the highest values in both K and O index d area was classified as 'tasty water.'

• Journal of Food Hygiene and Safety
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• v.32 no.6
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• pp.500-506
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• 2017

Kimchi cabbage is one of the four major vegetable crops in Korea. The total annual production of kimchi cabbage, the main material of kimchi, was 20,559 tons in 2015. Kimchi cabbage is one of the majer crops produced by farmers which accounts for about 80% of the total leaf vegetable production in Korea. As the consumption of environmental-friendly agricultural products increases, food safety is one of the major public health concerns. We analyzed the biological hazards of kimchi cabbage produced by two types of cultivation methos such as organic farming and conventional farming using various culture media and microscopy. A total of 432 samples were analysed for presence of sanitary indicator microorganisms (aerobic plate count, coliform count, yeast & mold) and food-borne pathogens (Staphylococcus aureus, environmental Listeria, Bacillus cereus). The population of sanitary indicating microorganisms and food borne pathogens was under 5 Log CFU/g in all tested samples. The results of total microorganism numbers of leaf surface showed a positive correlation to those of soil samples. Additionally, we examined chemical factors such as pesticide residues and heavy metals in soil samples. All tested samples did not shown contamination levels higher than the standard limit.

• Korean Journal of Plant Resources
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• v.32 no.4
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• pp.325-337
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• 2019

This study was conducted to analyze character of distribution of plants by landforms and altitude in Mt. myeonbong. The chemical properties of soil in this study sites were as follows; pH 4.86, organic 52.53 g/kg, $P_2O_5$ 7.57 mg/kg, potassium $0.18cmol^+/kg$, calcium $2.45cmol^+/kg$ and magnesium $0.49cmol^+/kg$. Generalists in the upper layer were analyzed as follows; Quercus mongolica, Pinus densiflora, Quercus variabilis, and specialists; Carpinus cordata, Tilia amurensis, Morus bombycis etc. In the middle layer, generalists were Betula schmidtii, Quercus mongolica, Sorbus alnifolia and specialists; Lindera erythrocarpa, Quercus serrata, Staphylea bumalda etc. Generalist of shrubs; Lindera obtusiloba, Rhododendron mucronulatum, Sorbus alnifolia, and specialists; Morus bombycis, Pinus densiflora, Deutzia glabrata etc. Generalists of herbaceous layer; Rhus tricocarpa, Lespedeza maximowiczii, Polygonatum odoratum var. pluriflorum and specialists; Liparis kumokiri, Davallia mariesii and Chrysosplenium flagelliferum etc.

• Journal of the Society of Disaster Information
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• v.18 no.2
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• pp.351-363
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• 2022

Purpose: The objective of this research is to find manufacturing employment clusters of the disaster safety sector in South Korea. Method: The LISA(Local Indicator of Spatial Association) analysis method is applied to the employment data of 229 local governments categorized by the 2019 Korean Standard Industry Classification and Disaster Safety Industry Special Classification. The LISA method identifies the spatial dependency of employment and the spatial cluster of industries. Result: Three research findings are summarized. First, employment of the disaster safety industry in South Korea occupies about six percent of the total manufacturing industry. The annual proportion is in increasing trend. Second, the employment cluster of the disaster safety industry is located in the western side of the Seoul metropolitan region. Third, manufacturing businesses of industrial safety goods preventing industrial accidents are concentrated in regions of Busan, Ulsan, Changwon, Gyeongnam, and Gimhae, where heavy and chemical industries and industrial complexes are formed. Conclusion: Investment and promotion policies are suggested to the manufacturing employment clusters of the disaster safety industry for fostering these regions. Research results can be used to the better policies for industrial development and employment improvement of manufacturing clusters of the disaster safety industry in South Korea.

• Korean Chemical Engineering Research
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• v.57 no.5
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• pp.637-651
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• 2019

In the event of a major accident such as an explosion in a refinery or a petrochemical plant, it has caused a serious loss of life and property and has had a great impact on the insurance market. In the case of catastrophic incidents occurring in process industries such as refinery and petrochemical plants, only the proximate causes of loss have been drawn and studied from inspectors or claims adjustors responsible for claims of property insurers, incident cause investigators, and national forensic service workers. However, it has not been done well for conducting root cause analysis (RCA) and identifying the factors that contributed to the failure and establishing preventive measures before leading to chemical plant's catastrophic incidents. In this study, the criteria of warning signs on CCPS catastrophic incident waning sign self-assessment tool which was derived through the RCA method and the contribution factor analysis method using the swiss cheese model principle has been reviewed first. Secondly, in order to determine the major incident warning signs in an actual chemical plant, 614 recommendations which have been issued during last the 17 years by loss control engineers of global reinsurers were analyzed. Finally, in order to facilitate the assessment index for catastrophic incident warning signs, the criteria for the catastrophic incident warning sign index at chemical plants were grouped by type and classified into upper category and lower category. Then, a catastrophic incident warning sign index for a chemical plant was developed using the weighted values of each category derived by applying the analytic hierarchy process (pairwise comparison method) through a questionnaire answered by relevant experts of the chemical plant. It is expected that the final 'assessment index for catastrophic incident warning signs' can be utilized by the refinery and petrochemical plant's internal as well as external auditors to assess vulnerability levels related to incident warning signs, and identify the elements of incident warning signs that need to be tracked and managed to prevent the occurrence of serious incidents in the future.

• Journal of Microbiology and Biotechnology
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• v.20 no.8
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• pp.1219-1225
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• 2010

Actinobacillus succinogenes, a representative succinicacid-producing microorganism, is seriously inhibited by ammonium ions, thereby hampering the industrial use of A. succinogenes with ammonium-ion-based materials as the pH controller. Therefore, this study isolated an ammonium-ion-tolerant mutant of A. succinogenes using a continuous-culture technique in which all the environmental factors, besides the stress (ammonium ions), were kept constant. Instead of operating the mutant-generating system as a nutrient-limited chemostat, it was used as a nutrient-unlimited system, allowing the cells to be continuously cultured at the maximum specific growth rate. The mutants were isolated on agar plates containing the acid-base indicator bromothymol blue and a high level of ammonium ions that would normally kill the parent strain by 100%. When cultured in anaerobic bottles with an ammonium ion concentration of 354 mmol/l, the mutant YZ0819 produced 40.21 g/l of succinic acid with a yield of 80.4%, whereas the parent strain NJ113 was unable to grow. When using $NH_4OH$ to buffer the culture pH in a 3.0 l stirredbioreactor, YZ0819 produced 35.15 g/l of succinic acid with a yield of 70.3%, which was 155% higher than that produced by NJ113. In addition, the morphology of YZ0819 changed in the fermentation broth, as the cells were aggregated from the beginning to the end of the fermentation. Therefore, these results indicate that YZ0819 can efficiently produce succinic acid when using $NH_4OH$ as the pH controller, and the formation of aggregates can be useful for transferring the cells from a cultivation medium for various industrial applications.

• Journal of Korean Society for Atmospheric Environment
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• v.26 no.2
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• pp.118-136
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• 2010

Photochemical characteristics of ozone ($O_3$) and its precursors such as $O_3$ budget and $O_3-NO_x$-VOC sensitivity were analyzed in different physico-chemical properties of air masses around the Mexico City Metropolitan Area (MCMA) using aircraft observations during March 2006. The physico-chemical properties of air masses were categorized into 5 groups: boundary layer (BL), biomass burning (BB), free tropospheric continent (FTCO) and marine (FTMA), and Tula industrial complex (TIC). Results from the $O_3$ budget analysis indicated that $O_3$ production for BL, FTCO, and FTMA (for BB and TIC) was mainly controlled by a photochemical production pathway, a reaction of NO with $HO_2$ (with $RO_2$), while the main pathway of photochemical $O_3$ destruction for BL, FTCO, and FTMA (for BB and TIC) was a reaction of $HO_2$ with $O_3$ (of $H_2$ with $O^1$(D)). In addition, most of air mass categories (especially FTCO) were estimated to be $NO_x$-sensitive for $O_3$ production with lower $NO_y$, higher ratios of the other indicator species (e.g., $O_3/(NO_y-NO_x$), $H_2O_2/HNO_3$, etc.), and the lower removal rate of radicals ($\leq$0.5) by the reaction of OH with $NO_2$ than those of the VOC-sensitive condition.

• Environmental Engineering Research
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• v.12 no.2
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• pp.64-71
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• 2007

The necessity of disinfecting playground soil is an important issue, because pathogenic protozoa, bacteria, and parasite eggs remain viable for several months and can infect children. UV irradiation has been used to decontaminate water but its effectiveness on soil is unclear. We determined the efficacy of UV radiation for inactivation of an indicator bacteria, E. coli (strain ATCC 8739), on playground soil. While 99% inactivation of E. coli in the soil was readily achieved by UV radiation within 55 min at $0.4\;mW\;cm^{-2}$, complete inactivation was not achieved, even after prolonged treatment at $4\;mW\;cm^{-2}$. This was attributed to the irregular surface of the soil. A small number of E. coli escaped the UV radiation because they were situated in indentations or under small particles on the soil surface. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) confirmed that the surface characteristics of the soil is the major limiting factor in the inactivation of E. coli by UV radiation. Thus UV treatment may not be adequate for disinfecting some soils and should be carefully evaluated before being used on playground soils.