• Journal of Food Hygiene and Safety
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• v.25 no.4
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• pp.367-375
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• 2010

The bacteriological and physiochemical analysis of sea water and sediments in Tongyeong harbor was conducted to evaluate sanitary conditions. The samples were collected at 8 stations established once a month from June, 2008 to May, 2009. During the study period, the range of temperature was from 6.7 to $25.2^{\circ}C$, transparency ranged from 1.2 to 2.6 m, chemical oxygen demand ranged from 1.90 to 2.92 mg/L, dissolved oxygen ranged from 6.2 to 10.5 mg/L, dissolved nitrogen ranged from 0.052 to 0.098 mg/L, phosphate ranged from 0.044 to 0.065 mg/L, respectively. Seafood, if eaten raw, carries the risk of food poisoning. Seafood poisoning is often cause by pathogenic microorganism originating from fecal contamination, such as Salmonella sp., Shigella sp. and norovirus. Fecal coliforms are an important indicator of fecal contamination. Therefore, data on fecal coliform are very important for evaluating the safety of fisheries in coastal areas. So, we investigated the sanitary indicate bacteria. The coliform group and fecal coliform MPN's of sea water in Tongyeong harbor were ranged from < 1.8~22,000/100 mL (GM 164.9 MPN/100 mL) and < 1.8~7,900 MPN/100 mL (GM 33.7 MPN/100 mL), respectively. Total coliform were detected 97.0% in 96 of samples and 68.9% of total coliforms were fecal coliforms. These results similar to another seawater detection ratio of total coloforms and fecal coliforms. The Vibrios was isolated and identified with VITEK system. Four hundred eighty strains that were obtained from sea water samples in Tongyeong harbor Detection ratio Vibrio alginolyticus, 34.2%, Vibrio parahaemolyticus, 13.8%, Vibrio vulnificus 10.0%, and V. mimicus 12.5% respectively. Vibrio cholerae O1, was not detected. During the study period, the ranges of water content, ignition loss, COD, and acid volatile sulfates in sediments in Tongyeoung harbor were 41.0~57.4%, 7.8~10.5%, 6.51~9.30 mg/g, 0.04~0.09 mg/g, respectively. Heavy metals in sediment of Tongyeoung harbor were Cd, $0.10{\pm}0.05$; Cu, $4.79{\pm}8.20$; As, $1.95{\pm}0.17$; Hg, $0.10{\pm}0.07$; $Cr^{6+}$, $0.34{\pm}0.12$; Zn, $125.33{\pm}16.40$; Ni, $16.43{\pm}1.93$ mg/kg.

• Korean Journal of Soil Science and Fertilizer
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• v.22 no.4
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• pp.329-336
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• 1989

A series of green house experiment was conducted to find but the effect of fertilizer application and inoculation of rhizobium on the changes of amide-N, ureide-N and $NH_4-N$ concentration in stem and root exudates of soybean plant growth. The results obtained were summarized as follows ; 1. Five strains of indigenous Rhizobium japonicum-nitrogen fixing activity($C_2H_2$-reducing activity) was more than 6.4 to 20.1 nmole/hr/tube-were identified from 37 soil samples in 22 areas of farmers field throughout country. 2. These identified 5 strains of rhizobium were obtained high nitrate reductase but low ammonium and nitrite oxidase activities. Among 5 strains of rhizobium the Rhizobium japonicum RjK-134 was applied for this green house experiment. 3. Dry matter yield was increased by the combination of inoculation of Rhizobium japonicum RjK-134 with no fertilizer and without nitrogen fertilizer application. However, dry matter yield was decreased with application of N and NPK with inoculation of rhizobium. 4. The concentrations of amide-N and ureide-N were increased in xylem sap than that of root exudate and higher concentration was obtained ar 30 days after planting than flowering stage (45 days after planting). 5. The combination of NPK application with inoculation of Rhrizobium japonicum RjK-134 enhanced the increase of amide-N and ureide-N concentration in xylem sap and root exudate. 6. High ammonium-N concentration in xylem sap and root exudate were obtained in combination with without-fertilizer under no inoculation of rhizobium and N and NPK application with inoculation of rhizobium.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.15 no.1
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• pp.41-50
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• 2010

We have developed an in-situ benthic chamber (BelcI) for use in coastal studies that can be deployed from a small boat. It is expected that BelcI will be useful in studying the benthic boundary layer because of its flexibility. BelcI is divided into three main areas: 1) frame and body chamber, 2) water sampler, and 3) stirring devices, electric controller, and data acquisition technology. To maximize in-situ use, the frame is constructed from two layers that consist of square cells. All electronic parts (motor controller, pA meter, data acquisition, etc.) are low-power consumers so that the external power supply can be safely removed from the system. The hydrodynamics of BelcI, measured by PIV (particle image velocimetry), show a typical "radial-flow impeller" pattern. Mixing time of water in the chamber is about 30 s, and shear velocity ($u^*$) near the bottom layer was calculated at $0.32\;cm\;s^{-1}$. Measurements of diffusivity boundary layer thickness showed a range of $180-230\;{\mu}m$. Sediment oxygen consumption rate, measured in-situ，was $84\;mmol\;O_2\;m^{-2}\;d_{-1}$, more than two times higher than on-board incubation results. Benthic fluxes assessed from in-situ incubation were estimated as follows: nitrate + nitrite = $0.18\;{\pm}\;0.07\;mmol\;m^{-2}\;d^{-1}$ ammonium $23\;{\pm}\;1\;mmol\;m^{-2}\;d^{-1}$ phosphate = $0.09\;{\pm}\;0.02\;mmol\;m^{-2}\;d^{-1}$ and silicate = $23\;{\pm}\;1\;mmol\;m^{-2}\;d^{-1}$.

• Journal of the Korean earth science society
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• v.45 no.1
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• pp.1-18
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• 2024

This study analyzed the effect of warming on PM_2.5 aerosol production in mid-latitude East Asia during June 2020 using PM_2.5 aerosol anomalies, which were identified by incorporating meteorological and climate data into the Weather Research Forecasting model coupled with Chemistry (WRF-Chem) model. The decadal temperature change trend over a 30-year period (1991-2020) in East Asia showed that recent warming has been greater in summer than in winter. Summer warming in East Asia generated low and high pressure in the lower and upper troposphere, respectively, over China. The boundary between the lower tropospheric low and upper tropospheric high pressure sloped along the terrain from the Tibetan Plateau to Korea. The eastern China, Yellow Sea, and Korean regions experienced a convergence of warm and humid southwesterly airflows originating from the East China Sea with the development of a northwesterly Pacific high pressure. In June 2020, the highest temperatures were observed since 1973 in Korea. Meanwhile, enhanced warming in East Asia increased the production of PM_2.5 aerosols that travelled long distances from eastern China to Korea. PM_2.5 anomalies, which were derived solely by inputting meteorological and climatic data (1991-2020) into the WRF-Chem model and excluding emission variations, showed a positive distribution extending from eastern China to South Korea across the Yellow Sea as well as over the Pacific Northwest. Thus, the contribution of warming to PM_2.5 aerosols in East Asia during June 2020 was more than 50%. In particular, PM_2.5 aerosols were transported from eastern China to Korea through the Yellow Sea, where the warm and humid southwesterly airflows implied wet scavenging of sulfate but promoted nitrate production.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.5
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• pp.469-475
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• 2002

The rotating biological contactor (RBC) was tested for treatment of aquacultural water in a pilot-scale recirculating aquaculture system. Performance of RBC on the treatment of nitrogen source such as total ammonia nitrogen (TAN), nitrite nitrogen and nitrate nitrogen and chemical oxygen demand (CODcr.) was evaluated. A system was stocked with nile tilapia at an initial rearing densities of $5\%$ and $7\%$ over 30 days. As increasing rearing density from $5\%$ to $7\%$, the TAN removal rates was increased from $39.4 g/m^3{\cdot}day$ to $86.0 g/m^3{\cdot}day$. But TAN removal efficiency was decreased from $24.5\%$ to $16.0\%$. The removal rate of $COD_Cr$ was higher than TAN. The RBC as an aerator was also evaluated for increasing dissolved oxygen concentration. For $5\%$ and $7\%$ of rearing density, the average aeration rate were $280 g/m^3{\cdot}day$ and $255 g/m^3{\cdot}day$, respectively.

• Journal of Food Hygiene and Safety
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• v.35 no.3
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• pp.261-270
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• 2020

The application of color retention agents (3 items), preservatives (17 items), and bleaching agents (6 items) as food additives in processed foods were investigated by food type. Among color retention agents, sodium nitrite was used the most with 257 cases, mainly in seasoned jeoktal (71.21%), ready-to-eat foods (7.78%), and breads (4.87%). Of the benzoates (1,236 cases) used as a preservative, sodium benzoate showed up most, in 1,215 cases, while 81.16% of these were in beverages such as beverage base (39.51%), mixed beverages (22.47%), and ginseng/red ginseng beverages (8.89%). Grapefruit seed extracts (3,291 cases) were applied to 44 types of processed foods such as sauces (54.65%), liquid tea (10.46%), and other products (5.15%). Ethyl p-hydroxybenzoate (2,957 cases) was applied to products (total 96.44%) such as sauces (92.15%), blended soy sauce (2.77%), and pickled foods (1.52%). Potassium sorbate was applied to a total of 789 cases, mainly pickled foods (40.43%) and processed fishery products (47.15%). All 27 cases of sorbic acid were applied to fish paste (100%). Of the bleaching agents, sodium bisulfite and sodium hydrosulfite were mainly used in confectioneries, breads or rice cakes, and potassium metabisulfite, sodium metabisulfite, and sulfur dioxide were mainly found in alcoholic beverages including fruit wine, while sodium sulfite was mostly used in pickled foods. These results are deemed useful in applying food additives to processed foods.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.1
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• pp.1-10
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• 2005

The purpose of this study was to evaluate the potential of a gamma irradiation to decompose 2,4,6-trinitrotoluene(TNT) in an aqueous solution. The decomposition reaction of TNT by gamma irradiation was a pseudo first-order kinetic over the applied initial concentrations($25{\sim}100mg/L$). The dose constant was strongly dependent on the initial TNT concentration. The removal of TNT was more efficient at pH below 3 and at pH above 11 than at neutral pH(pH 5-9). The required irradiation dose to remove over 99% of TNT was 40, 80 and 10 kGy, individually at pH 2, 7 and 13. The dose constant was increased by 1.6 fold and over 15.6 fold at pH 2 and 13, respectively, when compared with that at pH 7 When irradiation dose of 200 kGy was applied, the removal efficiencies of TOC were 91, 46 and 53% at pH 2, 7 and 13, respectively. Ammonia and nitrate were detected as the main nitrogen byproducts of TNT and glyoxalic acid and oxalic acid were detected as organic byproducts. The results showed that a gamma irradiation was an attractive method for the decomposition of TNT in an aqueous solution. However, regarding the application of high energy radiation for the TNT decomposition and mineralization, an application of an acidic pH below 3 to the solution before irradiation should be considered.

• Journal of Life Science
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• v.15 no.2 s.69
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• pp.225-230
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• 2005

The aim of this study was to examine the fluctuation in phytoplankton assemblages with regarding to environmental conditions and nutrients, which were surveyed quarterly over the fours seasons (February, May, July, and October). In turn, an understanding of biological effects should provide insights into a wide range of initiated Cochlodinium blooms in Narodo. Sampling was carried out throughout 2001 on the coasts of Busan (St. 1), Yeosu (St. 2), Narodo (St. 3), Kohung (St. 4), and Kwangdo (St. 5). The maximum surface water temperature was recorded in July, and it ranged from 20 to $22^{\circ}C$. Salinity showed no great variation, which maintained itself in the range of 29-34 psu. The maximum surface salinity was recorded in February, which was about 34 psu. The chlorophyll $\alpha$ concentration of the surface water ranged from 0.01 to $1.3\;{\mu}g\;1^{-1}$. The concentrations of $NH_{4}-N $ were persistently high from February to October; in particular, the peak was observed at St. 1 in February and May (0.15 and $0.19\;{\mu}mol\;1^{-1}$, respectively), while it was detected at St. 2 in July and October (0.22 and $2.2\;{\mu}mol\;1^{-1}$ respectively). Similar trends to those for $NH_4-N $ were observed in the concentrations of $NO_{2}-N$ and $NO_{3}-N$. In contrast to nitrogen, a distinct peak of $NO_{4}-P$ at St. 3, 4, and 5 was observed throughout year $(0.01-0.1\;{\mu}mol\;1^{-1}$ except for October. At St. 1 encounter a peak of cell number of 30,000 and $13{\times}10^3$ cells $1^{-1}$, respectively, in July and October. During the period of this study, the majority of the taxa were diatoms. The dinoflagellates were rather abundant after February, in particular at St. 3, 4, and 5 which attained an abundance of $10\~20\%$without marked fluctuation during the period of this study. At St. 3, the highest average cell width, $178.11\;{\mu}m$, was recorded: the highest cell length, $337.72\;{\mu}m$, was measured in July. Consequently, dinoflagellates bloom in July at Narodo influenced by warm water current are not only associated with a desirable development of cell morphometric characteristics, but also with the health growth of C. polykrikoides. During the period of this study, warm water currents caused an increased water temperature in Narodo, but did not change the amount of nutrients.

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.1
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• pp.52-60
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• 2000

This study was conducted to gain basic data for alleviation of gas emission and conservation of healthy soil environment by investigating an aspect of gas emission and microbial diversity due to the supplement of different fertilizers after application with a livestock manure compost in greenhouse soils. Green pepper was cultivated in clay loamy soil from April to August. Before planting, a livestock manure compost was applied with $741mg\;ha^{-1}$ on the basis of the phosphate content contained in compost. And then, deficient nitrogen for cropping was supplemented with either quick-acting fertilizer of urea or a controlled slow release fertilizer made from urea formaldehyde(U/F). $NH_3$ and R $NH_2$ gases emitted from soil showed a low concentration in the early stage but a maximum in 27 days after planting, then decreased rapidly and not detected after 33 days. Their average concentrations were 42% and 85% lower in the treatment of slow release fertilizer than that of urea fertilizer, respectively. $CO_2$ gas emitted under urea fertilization was ranged from 1,200 to $3,200mg{\ell}^{-1}$ and that in slow release fertilizer was $900{\sim}2,650mg\;{\ell}^{-1}$. The average concentration of urea treatment was $2,260mg{\ell}^{-1}$ and 30% higher than that of slow release fertilizer. The treatment of slow release fertilizer with the lapse of cropping time populated larger in numbers of bacteria, actinomycetes, nitrate bacteria and nitrate reduction bacteria, and ratios of bacteria and actinmycetes to fungi than that of urea fertilizer. But the number of fungi was higher in the treatment of urea fertilizer and denitrifying bacteria showed a similar trend in both treatments. The microbial diversity index, which calculated with numbers of 6 species of microorganisms, was decreased with increasing of growing stage in the range of 0.1 to 0.35 and that was higher in the tratment of slow release fertilizer than urea.

• Journal of Life Science
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• v.25 no.8
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• pp.896-902
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• 2015

This study was conducted to evaluate the substitution effect of red beet powder on sodium nitrite in emulsion-type pork sausages, and to investigate the effect of the addition of red beet powder on the physicochemical characteristics of emulsion-type pork sausages at 10℃ for 6 weeks. The treatments were divided into five groups: Control (sodium nitrite 0.01%), T1 (sodium nitrite 0.005% + red beet powder 0.5%), T2 (sodium nitrite 0.005% + red beet powder 0.25%), T3 (red beet powder 0.5%), and T4 (red beet powder 0.25%). In the CIE^*I didn’t delete this asterisk (*) because it might be a marker for something you wish to add later, but please note that if there is no significance for the asterisk, it should be removed as a typographical error. color of emulsion-type pork sausages, the lightness value of the control was significantly higher than for the other groups (p＜0.05). The redness value was higher in T1, whereas the yellowness value was higher in the T3 and T4 groups compared with the others (p＜0.05). The pH values of emulsion-type pork sausages were significantly decreased in the T3 and T4 groups by the addition of red beet powder (p＜0.05). However, the DPPH radical-scavenging activity was higher in the T1 and T3 groups than in the others (p＜0.05). The residual nitrite ion was the highest in the control group (p＜0.05). Therefore, it is determined that red beet powder can substitute for nitrite as a natural colorant, and it has a slightly antioxidant effect in emulsion-type pork sausages.