• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.6
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• pp.810-817
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• 2023

Oysters are a highly consumed seafood throughout Korea, but they have a short shelf life because they support rapid microbial growth due to their of high moisture content and fragile muscle tissue. We examined natural food additives including lactic acid bacteria fermentation powder, rosemary extract, and lemon juice for their ability to preserve raw oyster Crassostrea gigas quality. Samples were stored at 4℃, and microbiological and physicochemical analyses were conducted. Among the natural additives tested, lemon juice was the most effective. Lemon juice was thus applied at different concentrations (50-300 ppm) to quantitatively assess its effect on total viable cell count, pH, glycogen, soluble protein, and turbidity. 200 ppm was confirmed to be optimal, and is projected to extend shelf life by 2 days compared to the control group.

• Journal of the East Asian Society of Dietary Life
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• v.16 no.6
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• pp.707-716
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• 2006

To make tofu (soybean curd) with cuttlefish int the cuttlefish ink diluted 20-fold was added to soymilk in the ratio of 0%, 1%, 3%, 5%, 7% and 9% there is no respective comparison here respectively and the prepared cuttlefish inky tofu samples were stored for 15 days at $4^{\circ}C$. After storage, the tofu samples were tested for yield, pH, acidity, bacterial growth, sensory evaluations and physical properties. The yields of 7%(I7) and especially 9%(I9) cuttlefish ink tofu were higher than that of the control tofu(I0). The pH was decreased, but the acidity was increased with increasing storage period. The microorganism count of I9 was the lowest during the storage period. The turbidity gradually increased until 9 days of storage and rapidly increased at 12 days of storage. In the measurement of inky tofu color, the L and b values were decreased during the storage period. In the texture analysis, the hardness, gumminess and brittleness of inky tofu were increased until 12 days of storage but then decreased. Chewiness was decreased with increasing storage period. Springiness of Il and I3 was higher than that of I0. In sensory evaluation, color was increased with increasing cuttlefish inky concentration. Sleekness of I3 was the highest. Hardness and chewiness of inky Il and I3 were the highest. Springiness, cohesiveness and softness were the highest in I3. In overall acceptability, I3 gained the highest score.

• Journal of Korean Society of Water and Wastewater
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• v.18 no.5
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• pp.588-597
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• 2004

In this research, we investigated the variation of transmembrane pressure and permeate water quality with pre coagulation and sedimentation with iron based coagulant and chlorination of feed water for PVDF (polyvinylidene fluoride) based MF membrane filtration. NaCIO was fed to the membrane module with dosage of 0.5mg/L and maintained during filtration. To observe the effect of raw water, three types of raw and processed waters, including river surface water, coagulated water and coagulated-settled water, were applied. In case of river surface water, the transmembrane pressure increased drastically in 500 hours of operation. On the contrary, no significant increase in transmembrane pressure was observed for 1,200 hours of operation for coagulated water and coagulated-settled waters. The turbidity of permeate was lower than a detection limit of equipment for all raw waters. The removal efficiency of humic substances of coagulated water and coagulated-settled water was approximate ten times of that of surface river water. And, the removal efficiency of TOC and DOC was approximate two times of that of surface river water. From the results of plant operation, stable operation was maintained at $0.9m^3/m^2{\cdot}day$ filtration flux through the combination of pre-coagulation and pre-chlorination. However, the water quality of permeate was the best when pre-coagulation-sedimentation process was combined with pre-chlorination.

• Journal of Soil and Groundwater Environment
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• v.18 no.7
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• pp.54-62
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• 2013

Fine suspended solids and soluble heavy metals generated from mine drainage could destroy environment as the aesthetic landscapes, and depreciate water quality. Therefore, this research is focused on process development applied the actual field for controlling fine suspended solids and heavy metals, and so that bench-scale tests were performed for field application based on advanced researches. The field of mine drainage in this research was in H mine located Taebaek-si, Gangwon-do. The inclination plates were mounted 2 kinds of arrangement (octagon and radial types) in circle type settling basin. The inclination plates could be helped to settle of suspended solids; decreased 34% of suspended solids and 50% of turbidity in effluent. Radial type of inclination plates showed the results that is more efficient to settle of suspended solids (average to 3.45 mg/L) compared to octagon type. In the experiments to decrease retention time of mine drainage in settling basin from 6 hrs to 1.5 hrs, suspended solid concentration was exceeded to 30 mg/L as the standard for suspended solid at 10 days after the operation under tha retention time of 3hrs and 1.5hrs. In the tests for filtration, granular activated carbons were indicated the better effective to filtering and absorption of fine suspended solid and soluble heavy metals than anthracite.

• Korean Journal of Food Science and Technology
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• v.49 no.1
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• pp.35-43
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• 2017

The sensory characteristics of 12 commercial top-fermented beers were determined by sensory descriptive analysis. Beer samples were also analyzed for soluble solids, titratable acidity, pH, reducing sugar content, bitterness unit (BU), turbidity, hunter color values, amino acid content, total phenolic content, and DPPH radical scavenging activity. Five appearance, nine aroma, six flavor/taste, and four mouth-feel related sensory attributes were evaluated by a panel of nine judges. As the result of three way analysis of variance of descriptive data, all sensory attributes except "cereal" aroma and "salty" taste showed significant differences among the beers (p<0.05). Based on the principal component analysis of the descriptive data, samples were primarily separated by first and second principal components, which accounted for 78% of the total variance between the beers with high intensities of "yellow color", "caramel aroma", and "barley taste" versus "hop aroma", "sour", and "citrus aroma". In the correlation analysis between the sensory terms and physicochemical parameters, BU, total phenolic content, titratable acidity, soluble solids, and yellowness ($b^*$) showed significant positive correlations with citrus aroma, pineapple aroma, and fresh aroma characteristics.

• Journal of the korean society of oceanography
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• v.35 no.2
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• pp.109-123
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• 2000

Depositional processes of fine-grained sediments were investigated on the basis of sediment transport vector analysis and identification of benthic foraminiferal assemblages in Yoja Bay, southern coast of Korea. The bay is a semi-enclosed embayment where extensive mud flats occur with a width up to about 4 km. Most surface sediments are poorly sorted (sorting values: 1.9-3.0 ${\phi}$) mud and silt (mean grain size: 6.0-8.7 ${\phi}$), except for the tidal inlets with basement rocks locally exposed. Grain-size distribution shows a fining tendency toward the basin center near the Yoja Island, implying a possible existence of turbidity maximum and relatively rapid settling of fine-grained sediments. The agglutinated foraminiferal taxa are dominant in the inner bay and decrease in abundance toward the mouth of the bay. Species diversities are higher in the outer bay, due to mixing of the offshore faunas with those of the bay. Four groups of benthic foraminiferal assemblages, identified by cluster analysis, represent the bay. Biofacies I and ll with relatively lower diversities are dominated by Ammobaculites exiguus and Ammonia beccarii, suggestive of influx of fresh water. In contrast, biofacies III and IV with relatively higher diversities include increased amounts of calcareous genus Elphidium and Quinquelocuzina, accounting for strong influence of sea water from the offshore. The fluvial discharge in summer floods appears to develop a bay-wide, clockwise lateral circulation in Yoja Bay, a typical of well-mixed estuaries. Accordingly, the foraminiferal assemblages of the surface sediments well show a sign of this circulation. The dominant inflow of the offshore water into the western part of the bay has resulted in more extensive muddy tidal flats compared to the eastern narrower counterpart.

• Environmental Engineering Research
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• v.18 no.2
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• pp.95-101
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• 2013

Alternative sources of water are sought in some water stressed communities in the study area. The study focuses on the Aguata-Awka area of southeastern Nigeria. Aquifers occur at great depths, and surface waters may be far from homesteads. The scarcity of water has necessitated the people to adopt various local technologies for harvesting rainfall. The local technology includes collecting rainwater from roofs and channeling the water into large underground tanks, shallow wells and surface reservoirs. Large concrete tanks of $6m{\times}6m{\times}4m$ dimensions are often built underground and can store $144m^3$ of water. Surface reservoirs built on 4 m concrete pillar supports having dimensions of $10m{\times}10m{\times}4m$ and have a storage capacity of $400m^3$. Water samples were collected at 3 different locations of Agulu, Ekwulobia, and Awka and were analyzed for their physical, chemical, and bacteriological parameters. Results indicate a range of values for pH, 5.9 to 7.1; turbidity, 0.9 to 2.7; total dissolved solids, 80 to 170 mg/L; total hardness, 4.5 to 6.4 mg/L; magnesium, 1.2 to 1.4 mg/L; bicarbonate, 19.4 to 83.6 mg/L; and sulfate, 3.6 to 6.4 mg/L. Bacteriological analysis results were negative for fecal and total coliform counts. All parameters, with the exception of pH where aluminum and galvanized iron roofs are used for collection, fall within the recommended guidelines for drinking water quality of the World Health Organization, and the Standard Organization of Nigeria, new Nigerian standards for drinking water quality. Magnesium is above the maximum permitted level for consumer acceptability of the Nigerian standards for drinking water quality. The water can be classified as fresh moderately hard and soft. The water can be described as a calcium and bicarbonate type.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1996.06c
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• pp.692-700
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• 1996

The objective of this study is to develop a systematic purification plant using the metabolism of aerobic microorganisms. This system is subsequently aerated and continuously removes suspended solids and settling sludges caused by aerating pressure at the bottom of a lower pipe (i.e., Continuous Removal of Suspended solids and Settling sludges, CRSS). The CRSS plants are brought out by introducing fine air bubbles into the liquid phase of a lower pipe in the bio-reactor. These plant uses aeration pipe, with multiple inlets to sweep the floor of bio-reactor tank, instead of the conventional scraper mechanisms. The principal advantage of this system is that it can continuously remove very small or light particles that settles completely within a short time. Once the particles have been floated to the surface, they can be moved into the pipe and collected in the settling tank by sequently aerated pressure. The experimental results shows that about 99.0% of the biochemical oxygen demand(BOD), 99.3% of the suspended solid(SS), 92.3% of the total nitrogen(T-N), 99.0% of the turbidity(TU), 100% of the total coliform(TC)and ammonia was respectively removed during aerobic digestion for 9 days. These result indicates that the CRS S plants are very effective for reduction and deodorization of swine wastewater contaminants, and the efflux from CRS S can either be discharged in the river or used as nutrient solution of formulation for plant growth factories. The developed CRSS plant proved to be flexible and it can simply be adapted to any type of biological waste treatment problem.roblem.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.5
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• pp.391-399
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• 2010

This study was conducted to improve the antioxidative activity of instant noodles containing enzymatic extracts from Ecklonia cava (EEC). EEC has relatively better antioxidative activity than extracts from other indigenous plants in Jeju Island. The EEC (2.5 mg/mL) had 82.5% for the hydroxy radical, 78.4% for the DPPH radical, and 64.9% for the superoxide anion radical scavenging activities, and 65.2% for the cell viability (100 ${\mu}g/mL$). According to the texture of the dough, the DPPH free radical scavenging of uncooked instant noodles, sensory evaluation of cooked instant noodles, and turbidity of the cooking drip, the optimal EEC concentration was 1.8% for the instant noodles. The major amino acids in the instant noodles with EEC were glutamic acid (24.2%), proline (10.2%), valine (10.0%), and isoleucine (12.3%). The zinc and iron in the instant noodles were enhanced by adding 1.5-1.8% EEC. The antioxidant activity of instant noodles with EEC was 75.4% for the hydroxy radical, 74.1% for the DPPH radical, and 51.2 % for the superoxide anion radical scavenging activities.

• Journal of Korean Society of Water and Wastewater
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• v.24 no.5
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• pp.629-639
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• 2010

To evaluate the performance of high rate coagulation system(HRCS) for CSOs treatment, fundamental function of lab scale HRCS has been tested by using the Jar tester and lab scale HRCS. The optimum pH dose by Streaming Current value was found in the range of 5.3~6.0 in Fe(III), and in the range of 5.8~6.6 in Al(III) and the optimum chemical dose were 0.44mM of $Al_2(SO_4)_3$ and 0.93mM of $FeCl_3$. The removal efficiencies at optimum $Al_2(SO_4)_3$ dose were 75%($TCOD_{Cr}$), 97%(TP), 95%(SS) and 96%(turbidity), respectively. And the removal efficiency of particles with less than $5{\mu}m$ of diameter was 70% and that of particles with higher than $5{\mu}m$ of diameter was 90%. The optimum alum dose in lab scale HRCS was 150mg/L, and the treatment efficiency was the best with addition of 1.0mg/L polymer. The effect of Micro sand addition was not clear, because the depth of the sediment tank in lab scale HRCS was not long enough. But the HRT of this lab scale HRCS was able to be shorten less then 7 minutes by adding the micro sand. The surface loading rates with respect to using different chemicals were 0.43m/h with alum only, 5.78m/h with alum and polymer and 6.22m/h with alum, polymer and micro sand. As a result, HRCS using coagulant, polymer and micro sand developed in this study was evaluated to be very effective for CSOs treatment.