• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.5
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• pp.533-540
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• 2016

This study assessed the risk of an oyster-shucking site to establish the hazard analysis critical control point (HACCP) system model by measuring viable cell counts, coliform group Staphylococcus aureus foreign material on oysters, oyster-producing equipment, and washing water. The viable cell count and coliform group levels of the harvested raw oysters were 4.00 log CFU/g and 1.1×10² MPN/100 g, while those of washed oysters were 2.99 log CFU/g and (3.2−4.6) × 10 MPN/100 g, respectively. After washing the oysters, no Escherichia coli or pathogenic bacteria (E. coli O157:H7, Listeria monocytogenes, S. aureus, Salmonella spp., Vibrio parahaemolyticus, and Clostridium perfringens) were detected. Regardless of the location of foreign matter, up to 100% more metallic and non-metallic foreign matter was detected at 1.5 mmΦ than at 3.5 mmΦ, using a metal detector with increased sensitivity. According to the results, the critical control points (CCP) are the washing and metal-detection processes. These results can be used as basic data to improve sanitation at oyster-shucking sites in factories with an HACCP system.

• Journal of the Korea Convergence Society
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• v.11 no.10
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• pp.213-217
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• 2020

An eco-friendly water purifier was developed using natural minerals, plants, and sludge from water purification plants. A wastewater complex treatment system using this water purification agent was developed. The wastewater complex treatment system goes through the process of inflow of contaminated water, input of water purification agent, operation of a pressurized flotation device, sludge flotation, sludge collection and treatment water discharge. This device was applied to the removal of green algae in livestock desorption liquid, broiler washing water, factory wastewater, sewage treatment plant and pond to obtain excellent removal rate. The use of natural water purification agents for organic waste purification has not been investigated.

• Textile Coloration and Finishing
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• v.18 no.4
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• pp.11-19
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• 2006

Black-dyed PET fabrics were sputtered with stainless steel through DC-magnetron type device to investigate the possibility of coloration effect, and then considered the morphological structure and physical characteristics such as water permeation ability and washing fastness. Change in color was estimated on the basis of CIELAB color system. The color coordination of metal plated PET was shifted to yellow-red from red-blue. Colour difference$({\Delta}E^*)$ was increased by sputtering conditions with increasing ion current and treatment time. Especially, $Lightness(L^*)$ value of PET was remarkably increased by sputtering, whereas $Chroma(C^*)$ increased gradually. From SEM analysis, rough and uneven craters were found and thickened on the fiber surfaces with longer sputtering time. And washing fastness was a little poor and absorption ability slightly decreased. There were little changes of breaking load and breaking extension. It was evident that observed uneven craters in the plated thin layer resulted in the colour change of PET fabrics by sputtering treatments.

• Journal of Biosystems Engineering
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• v.34 no.3
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• pp.167-174
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• 2009

This study was conducted to develop an agaricus bisporus washing machine which uses compressed air to remove foreign materials attached on the surface of agaricus bisporus. A prototype of the washing machine was constructed, and performance of removing foreign materials was tested. Research results are as follows: 1. Several transferring methods including PE roller rotation, brush roller rotation, PE screw rotation, vibration plate, and belt conveyor were evaluated. Roller, screw, and vibration methods caused damages on the surface of the products, but belt conveyor method caused the least damages. 2. For air jet, a stationary nozzle type and a rotational type were evaluated. The best air jet nozzle was the jet-type nozzle, and the rotational type was more effective than stationary type nozzle. 3. With the conveyer belt, box type moving method and the rotational air jet nozzle, the washing machine showed the best performance when higher than 5.4${\times}$105 Pa of air jet pressure and lower than 0.047 m/s of moving speed was used. Working performance of the system was 650 kg/h, and the damaging rate was 1.2 %.

• Journal of Korean Society on Water Environment
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• v.28 no.1
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• pp.50-56
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• 2012

In this study, loess composites, loess with lanthanum and with aluminum, were made and evaluated for treatment of phosphorus removal in natural water system. Desiccation method for production of loess composite was superior to centrifugation method in obtaining high concentrated composites of lanthanum and aluminum. Washing of loess lanthanum composite by water did not deteriorat the lanthanum concentration in the composite, but this lowered the aluminum concentration of loess aluminum composite. Total of 15 and 37.5% of aluminum contents were removed after first washing treatment in aluminum loess of 0.05% and 0.1% respectively. However, no more aluminum loss was monitored with increase of washing times. Phosphorus removal efficiencies were not decreased with washed loess aluminum composite. Phosphorus removal was successfully achieved by adsorption of phosphate to loess composite at pH range of 5.0 ~ 8.0. Freundlich and Langmuir adsorption isotherm was observed in the adsorption of phosphate for loess composite. Dosages of 0.05% and 0.1% lanthanum composite for 95% of phosphorus removal could reduce its usage amount to 25% and 50%, respectively, comparing with dosage of loess alone. Dosages of 0.05% and 0.1% aluminum composite could reduce its usage amount to 48% and 63%, respectively.

• YAKHAK HOEJI
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• v.41 no.1
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• pp.30-37
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• 1997

In order to formulate a controlled release system for oral drug delivery, the microcapsules were prepared in w/o emulsion containing cefaclor as a water-soluble model drug by th e method of interfacial polycondensation. Gelatin wis selected as a suitable polymer for interfacial polycondensation. Gelatin solution containing drug was emulsified in an organic phase under mechanical stirring. After emulsification, terephthaloyl chloride was added as cross linking agent, followed by mechanical stirring, washing and drying. Physical characteristics of microcapsules were investigated by optical microscopy, scanning electron microscopy and particle size analysis. Mean particle sizes of gelatin microcapsules were, in the range, of about 20~50 ${\mu}$m. The microcapsules were in good apperance with spherical shapes before washing, but were destroyed partially after washing and drying, even though some microcapsules were still maintained in their shapes. Contents of cefaclor in the microcapsules were calculated by UV spectrophotometry after 3 days extraction with pH 4 carbonate buffer solution. The effects of cross linking time. pH. concentration of cross-linking agent, and temperature on drug release kinetics have been discussed extensively.

• Applied Chemistry for Engineering
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• v.8 no.3
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• pp.357-364
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• 1997

The objective of this study was to find optimum nonionic surfactants for clean up of soils contaminated by hydrocarbon oils. PIT(phase inversion temperature) measurements in ternary systems containing pure hydrocarbons, pure nonionic surfactants, and water were carried out and interfacial tensions were measured as a function of time for n-hexadecane oil drops brought into contact with various mixtures of nonionic surfactant and water. Batch surfactant washing experiments were performed based on the measurement, results of PIT and interfacial tension and the results showed that maximum removal of n-hexadecane occurred at the PIT of the system. For the $C_{12}E_5(C_{12}H_{25}O(CH_2CH_2O)_5H)$ system, maximum n-hexadecane removal of 73.4% occurred at the PIT of $52^{\circ}C$. In contrast, n-hexadecane removal at $25^{\circ}C$ and at $60^{\circ}C$, each corresponding to the conditions of below PIT and above PIT of the system, was found to be 57.1% and 57.0% respectively. The maximum removal of a hydrocarbon at the PIT of a system, where the hydrophilic and hydrophobic properties are balanced, was found to be due to the existence of high oil solubilization into a middle-phase microemulsion and ultralow interfacial of the order of $10^{-2}$ to $10^{-3}$ dyne/cm between middle-phase microemulsion and excess oil phase.

• Journal of Environmental Science International
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• v.26 no.1
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• pp.23-28
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• 2017

This study was aimed at determining the changes in heavy metal removal efficiency at different acid concentrations in a micro-nanobubble soil washing system and pickling process that is used to dispose of heavy metals. For this purpose, the initial and final heavy metal concentrations were measured to calculate the heavy metal removal efficiency 5, 10, 20, 30, 60, and 120 min into the experiment. Soil contaminated by heavy metals and extracted from 0~15 cm below the surface of a vehicle junkyard in the city of U was used in the experiment. The extracted soil was air-dried for 24 h, after which a No. 10 (2 mm) was used as a filter to remove large particles and other substances from the soil as well as to even out the samples. As for the operating conditions, the air inflow rate in the micro-nano bubble soil washing system was fixed at 2 L/min,; with the concentration of hydrogen peroxide being adjusted to 5%, 10%, or 15%. The treatment lasted 120 min. The results showed that when the concentration of hydrogen peroxide was 5%, the efficiency of Zn removal was 27.4%, whereas those of Ni and Pb were 28.7% and 22.8%, respectively. When the concentration of hydrogen peroxide was 10%, the efficiency of Zn removal was 38.7%, whereas those of Ni and Pb were 42.6% and 28.6%, respectively. When the concentration of hydrogen peroxide was 15%, the efficiency of Zn removal was 49.7%, whereas those of Ni and Pb were 57.1% and 42.6%, respectively. Therefore, the efficiency of removal of all three heavy metals was the highest when the hydrogen peroxide concentration was 15%.

• Korean Journal of Veterinary Research
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• v.29 no.3
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• pp.343-359
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• 1989

To study the effects of ibaraki virus on preimplantation mouse embryos collected from prepubertal ICR and BALB/cByJ mice (30~40days old) by superovulation, zona pellucidaintact(ZPI) or free(ZPF) embryos(n=774) of 4- to 8-cell and morulae were exposed to $10^{5.8}$ $TCID_{50}$ of the virus up to 96 hours. The embryos were examined morphologically by observing the degeneration and hatching rates, and virologically and immunologically by determining the presence of infection with the virus, in addition, the effect of washing the embryos to remove virus possibly attached to was also investigated. The ZPI 4- to 8-cell embryos and morulae exposed to the virus showed considerably higher degeneration rate than those not exposed, for 96, and for 72 to 96 hours, respectively(p<0.01). The ZPF 4- to 8-cell embryos and morulae exposed to the virus showed considerably higher degeneration rates than those not exposed, throughout the whole culture hours in vitro (p<0.01). The ZPI 4- to 8-cell embryos and morulae not exposed to the virus showed considerably higher rates of hatched blastocyst than those exposed (p<0.01). The virus infection rates of the ZPF 4- to 8-cell embryos and morulae were significantly higher than those of the ZPI embryos according to cell culture system. The viral antigen was detected exclusively on the zona pellucida of ZPI embryos, while the antigen was evenly distributed in the blastomeres of ZPF embryos by the immunofluorescent assay. In the ZPI embryos exposed to ibaraki virus, the virus was detected in the two times-washing groups, but not in the ten times-washing groups. The results indicated that zona pellucida of murine embryos would provide an effective protection and that ten times-washing of the ZPI embryos previously exposed to the virus was effective to remove virus from the embryos.

• Korean Journal of Materials Research
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• v.10 no.6
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• pp.445-449
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• 2000

Nickel ferrite $(Ni_{0.75}Fe_{2.25}O_4$ was synthesized by co-precipitation method in order to investigate its behavior under conditions of the reactor coolant system in pressurized light water nuclear power plants. Ammonia or potassium carbonate was used as a solution pH control agent, and aqueous ammonia or potassium carbonate solution or secondary distilled water was used as a co-precipitate washing agent. The effects of the pH control agent and the co-precipitate washing agent on the production yield on the basis of the Ni/Fe molar ratio and the particle characteristics of final products were investigated by XRD, SEM, EDX and XPS. The production yield was almost congruent with that of the initial aqueous mixture in case of using potassium carbonate as a pH control agent, while in case of using ammonia, it was quite changed. The difference seemed to be due to the effects of $Ni^{2+}{\leftarrow}NH_3$complexation in the aqueous solution and of the pH of co-precipitate washing agent.