• 한국해양학회지
• /
• v.22 no.3
• /
• pp.191-206
• /
• 1987

Keum River discharges 6.4billion tons of fresh water annually into the Yellow Sea. More than 60% of the total discharge is concentrated in summer, differentiating distinct low-discharge and high-discharge periods for the estuarine environment. The concentration of SPM(Suspended Particulate Matter) is, in general, very high, except sometime during rainy season, and turbidity maximum is often observed, especially during spring-tides(Lee and Kim, 1987).

• Journal of Environmental Impact Assessment
• /
• v.19 no.4
• /
• pp.367-380
• /
• 2010

수산 해양환경적 측면에서 중요한 위치에 있는 황해(Yellow Sea)의 해양 생태계 변화과정에 대 한 체계적이고 심층적인 연구을 위하여 기후 변화와 관련된 생태 및 환경변화에 대한 황해 해역의 반응성 연구가 필요한 실정이다. 본 연구는 황해해역에서 수온 상승에 따른 클로로필의 변화를 살펴보고, 지구온난화가 해양환경과 생태계에 미칠 영향을 예측하고자 하였다. 황해해역에서 해수유동 모델의 결과를 기초 입력자료로 활용하여 클로로필과 상호작용을 하는 육상유입부하량, 저질 영양 염용출량 및 생물학적 파라메타 등을 입력하여 현재상태를 재현하였다. 우리나라 주변 해수의 온도가 지난 10년간 약 $0.75^{\circ}C$ 상승했다고 가정하였을 때, 본 실험에서는 수온이 선형적으로 연간 $0.075^{\circ}C$ 씩 상승한다고 가정하여 10년 후까지의 Chlorophyll-a 농도 변화를 예측하였다. 예측 결과, 연구해역의 중앙부에서는 전체적으로 농도가 높아지고, 우리나라 연안해역에서 Chlorophyll-a 의 농도가 낮아지는 것으로 예측되었다. 본 연구의 결과를 기초로 하여 10년 이상의 장기적인 예측실험을 한다면 기후변화가 황해해역의 생태계 변화에 미치는 영향을 파악할 수 있을 것으로 기대된다.

• Journal of Navigation and Port Research
• /
• v.34 no.5
• /
• pp.383-388
• /
• 2010

Lab scale experiment study was carried out for biological process development on cruise. SBR(Sequence Batch Reactor), MBR(Membrane Bioreactor), and MSBR(Membrane Sequence Batch Reactor) system were investigated for practical application on shipboard sewage treatment. From the results it was suggested that MSBR system might be suitable process for cruise in terms of pollutant removal efficiency, maintenance and special environmental conditions of cruise. About 99% of BOD, 98% of COD and 99% of SS were removed in MSBR system. In addition, about 76% of total nitrogen was reduced and the total phosphorus reduction averaged 59%.

• Journal of Korean Society of Water and Wastewater
• /
• v.19 no.2
• /
• pp.200-208
• /
• 2005

In this study, a new submerged membrane bioreactor process packed with granular sulfur (MBR-GS) was operated to identify the biological nitrogen removal behaviors with plating wastewater containing high-strength $NO_3{^-}$ concentration. The continuous denitrification was carried out at $20^{\circ}C$ with various nitrogen loading rates using synthetic wastewater, which composed of $NO_3{^-}$ and $HCO_3{^-}$, but also actual plating wastewater, which was collected from the effluent of the H metal plating company. As a result, high-rate denitrification in the range of $0.8kg\;NO_3{^-}-N/m^3\;day$ was accomplished at nitrogen loading rate of $0.9kg\;NO_3{^-}-N/m^3\;day$ using synthetic wastewater. Also, higher-rate denitrification with actual plating wastewater was achieved up to $0.91kg\;NO_3{^-}-N/m^3\;day$ at the loading rate of $1.11kg\;NO_3{^-}-N/m^3\;day$. Additionally, continuous filtration was possible during up to 30 days without chemical cleaning in the range of 20 cmHg of transmembrane pressure. On the basis of the proposed stoichiometry, ${SO_4}^{2-}$ production could be estimated efficiently, while observed alkalinity consumption was somewhat lower than theoretical value. Consequently, a new process, MBR-GS is capable of high-rate autotrophic denitrification by compulsive flux and expected to be utilized as an alternative of renovation techniques for nitrogen removal from not only plating wastewater but also municipal wastewater with low C/N ratio.

• Korean Journal of Environment and Ecology
• /
• v.24 no.1
• /
• pp.62-68
• /
• 2010

This study was conducted to find out how the germination, phenology and leaf morphology of Phytolacca insularis(endemic species of Korea) and P. americana(alien species) react to the global warming situation. Seed and seedlings of two species were sampled and placed under two separate conditions for the experiment. One of the seed and seedlings was treated in the glass house with control(ambient $CO_2$+ambient temperature, (AC-AT), and the other with control(elevated $CO_2$+ elevated temperature, EC-ET), over the period of one year, 2008-2009. The germination rate of two species was fast, and the time of their germination started early, when they were treated at EC-ET than at AC-AT. Furthermore, the germination rate of Phytolacca insularis(endemic species of Korea) was found to be comparatively lower than that of P. americana(alien species). The former showed only vegetative growth whereas the latter showed both vegetative growth and reproductive growth in one year period. The more $CO_2$ degree and temperature increased, phenological responses of two species, including leaf growth, the formation of flower stems, flowering, and fruit maturing, became much faster, and the time of their leaf-yellowing was delayed. The lamina length of P. insularis was not significantly affected by elevated $CO_2$ and temperature. The lamina length of P. americana, on the other hand, became longer at EC-ET than at AC-AT, but the leaf width of both species increased at EC-ET. As for the number of leaves, both species showed no difference. Finally, the ratio of the leaf area of P. insularis was high at AC-AT, but P. americana was high at EC-ET. These results indicate that P. americana, aliens species, reacts more sensitively to global warming than P. insularis, endemic species, does.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.36 no.11
• /
• pp.1465-1471
• /
• 2007

Response surface methodology (RSM) was employed to optimize extraction conditions in order to find the maximal functional properties of fluid Cheonggukjang. Based on central composite design, a study plan was established with variations of microwave power, ethanol concentration, and extraction time. Regression analysis was applied to obtain a mathematical model. The maximum inhibitory of tyrosinase activity was found as 26.75% at the conditions of 30.56W microwave power, 2.40 g/mL of ratio of solvent to sample content and 10.00 min extraction time, respectively. The maximum superoxide dismutase (SOD)-like activity was 53.23% under the extraction conditions of 108.42 W, 4.38 g/mL and 7.84 min. Based on superimposition of three dimensional RSM with respect to extraction yield, inhibitory of tyrosinase activity and SOD-like activity obtained under the various extraction conditions, the optimum ranges of extraction conditions were found to be microwave power of $55{\sim}75$ W, ratio of solvent to sample content of $2{\sim}5$ g/mL and extraction time of $3.5{\sim}15$ min, respectively.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.42 no.3
• /
• pp.457-463
• /
• 2013

The purpose of this study was to apply the Hazard Analysis Critical Control Point (HACCP) system to the production of dressing. The hazard analysis examined the main materials, industrial water, microbial evaluation, and airborne microorganisms of each working area, as well as the pathogenic microbial contamination risk. The survey was conducted at SJ Company in Jincheon (Chungchengbuk-do), Korea for 30 days from April 1, 2012 to April 30, 2012. The results showed that raw material microorganisms had a total plate count in industrial water below $3.00{\times}10$ CFU/mL in working room I, working room II, the packing room, washing water, and the inspection room for five times in each place. During dressing production (including heat treatment and mixing), general bacteria were detected at an average of $3{\times}10$ CFU/mL, but yeast, mold, and pathogenic bacteria were not detected. Airborne microbiological evaluation (for total plate count, yeast, and mold) found levels below the legal limit at each working area. While workers were positive for microbes in total plate counts, coliform and Staphylococcus aureus were not detected. In conclusion, standards for hygienic management should be established to prevent and decrease hazards, such as general bacteria and pathogenic microorganisms (for example, E. coli, B. cereus, Listeria spp, Salmonella spp, Staph. aureus, Clostridium perfringens, yeast, and mold), and to found critical limits for microorganisms with an HACCP system.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.37 no.7
• /
• pp.900-907
• /
• 2008

The physicochemical properties of black rice flours produced from dry and wet milling were carried out to investigate their applications in food processing industry. The dry milled black rice flours showed lower fat, protein, ash, and anthocyanin contents than those of wet milled black rice flours with no effect due to number of millings. Average particle sizes ($379{\sim}288\;{\mu}m$) of dry milled flours were bigger than those ($336{\sim}253\;{\mu}m$) of wet milled flours. Particles with 60 mesh or more increased with increasing milling times. Wet milled flours had higher damaged starch, water solubility index (WSI), and water absorption index (WAI) compared to dry milled flours. Pasting properties measured by rapid visco analyzer (RVA) resulted in higher pasting temperatures in dry milled flours ($62.5{\sim}69.4^{\circ}C$) than wet milled flours ($46.1{\sim}46.4^{\circ}C$). As the number of milling times increased, pasting temperature of wet milled flours were not effected. Dry and wet milling resulted in reduced trough, final viscosity, and consistency with increasing milling times.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.32 no.5
• /
• pp.661-666
• /
• 2003

This research was aimed at evaluating the effects of natural antioxidants on lipid oxidation and sensory quality in cooked, chill- stored and reheated Wanjajun prepared with pork meat (short shank). Sage (SA) and combinations of herbs; basil/mints (BM), rosemary/parsley/thyme (RPT) were used as sources of antioxidants. The products were pan-fried in a medium layer of soybean oil and then stored in a refrigerator at 3$^{\circ}C$ for 8 days after rapid chilling. The process of heat treatment of Wanjajun caused changes in the chemical composition of products and simultaneously, thermal oxidative reaction was initiated. During storage of products in a refrigerator, further hydrolytic and oxidative processes in the lipid extraction were progressed. Acid value was increased, peroxides and malonaldehyde formation gradually were increased during cool storage. Addition of garlic, sage and combinations of herbs retarded the process of oxidation. Wanjajun made with addition of SA and RPT showed good quality in antioxidative potential after 8 days of storage. The sensory effect of herbs on undesirable warmed-over flavor was in order of : SA>RPT>BM.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.42 no.2
• /
• pp.255-261
• /
• 2013

This study investigated changes in the physicochemical characteristics and coffee flavors of coffee beans under different roasting conditions. Four different kinds of roasted coffees were analyzed using a headspace gas chromatographic technique. The moisture content and total acidity of roasted coffee decreased whereas the pH and weight loss (%) increased, as coffee beans were roasted at higher temperatures. The Hunter's color values of the roasted coffee (indicating L (lightness) and b (yellowness)) decreased as the roasting temperature of the coffee beans increased, but a (redness) value only increased with light roasting. We also noted that the color of the Arabica coffee was darker than that of the Robusta coffee. The aroma compounds, acetaldehyde, acetone, 2-methylfuran, 2-methylbutanol, 2-methylpyrazine, furfural, 2-propanone, furfuryl alcohol, 2,5-dimethylpyrazine and furfuryl acetate were mainly analyzed. A sensory evaluation of all light-roasted coffees had flavor and sourness and those of all medium-roasted coffees had heaviness and finishness.