• Journal of Korean Society on Water Environment
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• v.25 no.6
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• pp.840-848
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• 2009

Spatial and temporal distributions of POC and DOC were surveyed in the North Han River system, Korea The proportion of algal cells was calculated in four reservoirs (Lakes Soyang, Paro, Chunchon, and Uiam). Monthly average DOC concentrations ranged from 1.5 to 2.3 mg C/L, and POC showed larger variation than DOC (range 0.3 to 1.9 mg C/L). The average proportion of POC in TOC was higher than those of typical natural lakes. Due to the influence of the Asian summer monsoon, the seasonal variation in POC concentration depended on heavy rain events occurring during the summer. POC concentrations increased during the summer monsoon season due to turbid storm runoff laden with debris, while DOC concentrations did not increase. The highest POC concentrations were observed in Lake Soyang in 2006 when a severe rain event occurred. In two deep stratified reservoirs (Lake Soyang and Paro) storm runoffs formed an intermediate turbidity layer with high POC and chlorophyll concentrations which is thought to originate from terrestrial debris and periphyton transported by inflowing streams. The proportion of algal cells in total POC was much lower than for most natural lakes, and it varied with season; low in the monsoon season and high in dry seasons with algal blooms. An analysis of POC concentration and chlorophyll a concentration showed that the ratio of POC/Chl.a varied from 24 to 80.

• Korean journal of food and cookery science
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• v.26 no.6
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• pp.831-839
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• 2010

The results of wet noodles added with 0, 1, 3, 5, and 7% freeze-dried maesangi powder demonstrate that the addition of maesangi powder up to 5% was desirable formation of noodles. The moisture contents of wet noodle 35.48~36.42%. As the added amount of maesangi powder increased, weight, volume, water absorption, and turbidity the wet noodle soup after cooking increased. Measurement of color changes between before and after cooking the wet noodles found that as the added amount of maesangi powder increased, the lightness and yellowness increased. Measurement of texture after boiling found that, hardness, chewiness and gumminess tended to increase as the amount of added maesangi powder increased whereas, springiness and cohesiveness were significantly different between the different samples. The results of the sensory evaluation showed that the 3%-added group was the best for color, flavor, and taste while the control groups had the best texture. For overall acceptability, the 3%-added group showed found the highest preference level. Measurement of the changes in total viable cells during storage at $5^{\circ}C$ for 18 days found that 6-days was the optimal storage period for the noodles from the control groups and added groups. As the storing period increased, the maesangi powder added groups showed slower propagation speed for viable cells compared to the control groups.

• Journal of Korean Society on Water Environment
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• v.28 no.3
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• pp.418-425
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• 2012

Dam construction in a river can change its hydrological pattern and trap sediments, which results in ecological changes in the downstream. It is a common phenomenon in the downstream of dams to have decreased sediment flow and increased periphyton. Artificial floods and sediment application are suggested as mitigation practices in order to simulate natural process of flood; transporting sediment and sloughing periphyton off. In this study the effects of artificial floods on periphyton were examined by applying sand artificially and discharging water from a dam (Yangyang Dam, Korea). The study area has been suffering from turbidity problems caused by shore erosion of the dam. The accumulation of inorganic sediments and increase of periphyton on the river bottom are the major factors of habitat deterioration in the downstream reaches. Artificial flood and artificial addition of sand was performed in summer and the effects were measured. Piles of applied sands were washed off easily by discharge and it enhanced the periphyton sloughing effect. The removal efficiency of periphyton was 50 ~ 80% within the 2 km reach from the dam. In conclusion artificial floods and sand application can be a good mitigation measure for the habitat rehabilitation after a dam construction in streams.

• Proceedings of the Membrane Society of Korea Conference
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• 1997.04a
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• pp.55-62
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• 1997

In Japan, the membrane filtration is becoming a common technology for municipal water supply system especially for small plant. 6 years before (1991), the national research project of membrane filtration for small plant has started. The project was named as "MAC 21", MEMBRANE AQUA CENTURY 21. In the project the Ministry of Health and Welfare, 8 universities and 18 water treatment plant companies have been involved. This was the first attempt to research a common theme in joint with government, universities and private companies. After three years, the guide line for membrane filtration application for small plant has been established. This has promoted to install some actual plant. And also, another joint research for "RESEARCH OF MEMBRANE FILTRATION FOR ADVANCED WATER TREATMENT" has started in 1994 and completed in March, 1997. The project was named as MAC21. In the former project the main objectives were removal of turbidity and bacteria from water. However, in new project the objective was establishment of the further advanced membrane filtration technology which would be applicable for trace chemical components removal such as tri-halo-methane pre-courser, agricultural chemicals removal, offensive smell and taste removal and virus removal. For the objectives, application of nanofiltration and hybrid-system, a combination of micro-filtration ultra-filtration with biological, ozone and activated carbon treatment process have been studied. In addition, application of membrane filtration for treatment of back-wash waste water originated from membrane filters and conventional sand filters has.been studied. At the end of March of this year, about 30 membrane filtration plants are actually supplying the water, the total treatment capacity is about 6,000 m$^{3}$/day and another 20 will be installed within one year.led within one year.

• Korean Journal of Food Science and Technology
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• v.32 no.3
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• pp.674-680
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• 2000

This study was conducted to investigate the effect of soaking and blanching of chicken- head on the quality of chicken-head broth. The longer soaking time, the lower the contents of free amino acids and nucleotide and its derivatives in chicken-head broth. Sensory panel showed that increased soaking time led to decreases in the degree of darkness, yellowness, turbidity and the intensity of bloody flavor and organ meat-like flavor. Optimal soaking time was determined to be 30 min according to the result of sensory evaluation. While the broth using unblanched chicken-head contained more free amino acids, nucleotide and its derivatives than the broth using blanched one, sensory test revealed no significant difference between two broths. Therefore, blanching was found to be unnecessary process for the preparation of chicken-head broth.

• Food Science and Preservation
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• v.18 no.5
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• pp.678-683
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• 2011

The effects of coagulant types (magnesium chloride, calcium chloride, calcium sulfate, glucono-${\delta}$-lactone) on yield, quality properties and storability of astringent persimmon powder added tofu were investigated. Yield, hardness, chewness, crispness, and overall acceptability of tofu coagulated by glucono-${\delta}$-lactone were higher than those coagulated by the others. L value, a value, pH, soaking-solution turbidity, and total aerobic bacteria of glucono-${\delta}$-lactone coagulated tofu were lower than those coagulated by the others. Calcium sulfate and calcium chloride coagulated tofu showed relatively high L and b values. Magnesium chloride coagulated tofu had higher sensory score for firmness, taste, overall acceptability than calcium chloride and calcium sulfate coagulated tofu, but there was no significant difference between magnesium chloride and glucono-${\delta}$-lactone. The results suggested that glucono-${\delta}$-lactone and magnesium chloride were found to be the suitable coagulants for processing of the persimmon powder added tofu.

• Korean Journal of Food Science and Technology
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• v.21 no.2
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• pp.197-202
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• 1989

This study was conducted to investigate the characteristics of Sikhye as affected by different amount of cooked rice and malt, and by different kinds of sweeteners. In the various Sikhyes made with the different amount of cooked rice and malt, the degree of such sensory properties as color and malt odor significantly increased with the increased amount of malt. As the amount of cooked rice increased, sensory properties such as turbidity, sweetness and viscosity increased. Reducing sugar content in Sikhye was consistent with those of sensory evaluation on sweetness. Sikhyes containing aspartame, saccharin, sorbitol or sucrose at equisweet levels to Sikhyes containing 10% sucrose showed different sensory characteristics except sweetness. Sikhye sweetened with mixtures of substituted sweeteners showed increase in sweetness and differences in bitterness and astringency compared with Sikhye containing 10% sucrose.

• YAKHAK HOEJI
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• v.54 no.2
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• pp.106-111
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• 2010

The chemical structures of eight compounds purified from two plants (Polygala tenuifolia Willdenow and Dioscorea batatas Decene) were determined and their anti-microbial activity against three microbial strains (Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans) was tested. The three micro organisms were cultured in 96-well plates or Petri dishes without (control) or with the eight compounds added at concentrations of 100 to 0.01 ${\mu}M$ (wt/vol). The growth of the microorganisms in the medium was examined after a 24-h incubation. The inhibitory effect of each compound on the growth of the microorganisms was calculated from the optical density measured at 595 nm, turbidity, and size of the inhibition zone around the treated paper disc. The minimum inhiitory concentration (MIC) of compounds 4 to 7 against S. aureus was 0.08, 0.05, 1.3 and 0.02 ${\mu}M$, respectively, and 0.09, 0.1, 0.2 and 100 ${\mu}M$ against C. albicans. The $IC_{50}$ (50% inhibition) values of compounds 5 and 6 were 3.1 and 6.4 ${\mu}M$ against S. aureus, respectively, and 10 and 2.4 ${\mu}M$ against C. albicans. Therefore, compounds 4 to 6 were the most potent anti-microbial agents among the eight compounds tested.

• Journal of Korean Society of Water and Wastewater
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• v.13 no.1
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• pp.81-94
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• 1999

This study aims at a proposal of the plan that can improve raw water quality by an experimental study using influent water of Nak-dong river, which has been used as raw water for drinking in U-city, through the establishment of the submerged biofilter process PILOT PLANT of media packing channel method. From the analysis of removal efficiency for each water quality item of the collected sample, following results are obtained. First of all, the removal rate of suspended material, BOD, COD, T-N, TOC, turbidity, and $NH_3$ -N appear 82%, 78%, 42%, 15%, 57%, 43%, 54%, and 55% respectively and it is known that the submerged biofilter process of media packing channel method takes effects on water quality improvement from the above analysis results of water treatment efficiency. And the analyzed results for water temperature, residence time, and activities of microorganism, which can be the factors affect on water quality improvement, are as follows. 1) The removal rate variation of SS, BOD, and COD attendant on water temperature change is examined and it is known that the removal rate increases at $13^{\circ}C$ or above. 2) The removal rate of SS, BOD, and COD attendant on residence time is most active in the range of 0~18hr, 0~1.8hr, 0~2.7hr respectively, so it is found that the removal rate becomes smaller after 2.7hr. 3) From the examination of microorganism activity with the abundance of normal bacteria, it is found that the floating bacteria decrease as the flow distance from raw water inflow point of PILOT PLANT increases, and the adhesive bacteria have no concern with the flow distance. And it its known that the biomass of fine algae decreases as the flow distance from the raw water inflow point of PILOT PLANT increases from the examination with Chl-a.

• Korean journal of food and cookery science
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• v.24 no.5
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• pp.665-671
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• 2008

The principal objective of this study was to assess the quality properties of noodles to which browned oak mushroom (Lentinus edodes) paste was added at concentrations of 10%, 20%, and 30% to wheat flour, respectively. With regard to the cooking properties of the noodles, the weight and water absorption of the cooked noodles increased with increasing paste contents, but the turbidity of the noodle soups decreased (p<0.05). The hardness and gumminess of the uncooked and cooked noodles decreased significantly in proportion to the quantity of added paste, except in the case of the cooked noodles with 30% paste. The springiness and cohesiveness of both noodles with Lentinus edodes paste were significantly higher than in the controls. The lightness of the uncooked and cooked noodles decreased in accordance with the amount of added paste. However, the yellowness of both noodles was significantly increased. Moreover, the results of our sensory evaluation showed that the cooked noodles with 20% and 30% added Lentinus edodes paste had higher values. Thus, Lentinus edodes paste added to a concentration of up to 30% was shown to effectively improve the quality of noodles.