• Journal of the Korean Society for Heat Treatment
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• v.15 no.5
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• pp.213-218
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• 2002

In order to develop the economic and environmental water-soluble black coloring agent, some adequate chemical mixtures were mixed and this solution was applied to coat quenched and tempered 51B20 steel bolt. Some basic properties of the solution and characteristics of the coated film in addition to the corrosion resistance were investigated. The developed 100 kg of water-soluble black coloring agent solution was a chemical mixture consisted of 10 kg of aqueous coloring agent, 40 kg of surface active agent, 0.3 kg of anti-foam agent and $50{\ell}$ of water. The coated film of the bolt was composed of hard layer of about $2{\mu}m$ and the disbondable soft layer of about $4{\mu}m$ above the hard layer. Many surface active agents peaks and a few hydrophilic peaks were observed in the coated film. Surface roughness value of the coated bolt was lower than that of the non-coated bolt. Corrosion resistance of the coated bolt considerably improved and also relatively showed a good polarization resistance at test condition of $40^{\circ}C$ colorizing temperature and 5% the solution concentration in 3% NaCl anodic polarization test. Initial appearance time of the surface rust was greatly retarded owing to the coated film in salt spray test.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.8 no.2
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• pp.73-84
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• 1975

The present study was conducted to evaluate the effects of oil spill from the wastewater of Yeosu Refinery on water quality of hard clam culture beds in Taein-Ri, Kwang Yang Bay. Wastewater and oil spill may reach to the culture beds in 6-8 hours by tidal current movement. Water quality is nearly normal as unpolluted sea water except the concentration of n-hexane extractive chemicals which shows higher than unpolluted sea water in period of September to October in 1973. It may be caused by wastewater of Yeosu Refinery.

• Journal of Pharmaceutical Investigation
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• v.33 no.2
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• pp.85-89
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• 2003

Piroxicam-arginine complex was prepared to improve the solubility and dissolution rate of poorly water-soluble piroxicam. Its formation was identified by infrared spectrophotometry, differential thermal analysis and dissolution rate. Piroxicam complex dispersible tablets, commercial $Feldene^{\circledR}$ dispersible tablets and piroxicam physical mixture hard capsules were prepared to compare dissolution rate in water. Dissolved amounts (%) after 15 mins of piroxicam complex dispersible tablets, commercial $Feldene^{\circledR}$ dispersible tablets and piroxicam physical mixture hard capsules were 98%, 48% and 10%, respectively. The solubility of complex in water was significantly higher than that of piroxicam itself. In vivo, pharmacokinetic parameters were obtained after oral administrations of piroxicam complex and physical mixture at a does of 2 mg to New Zealand White Rabbit. The $C_{max}$ of piroxicam complex was similar to that of piroxicam. However, there were much difference between the two formulations with regard to $T_{max}$ and AUC. The $T_{max}$ of piroxicam alone was 4 hours, but that of piroxicam complex was 0.8 hours. In addition, the AUC of piroxicam complex was 1.38 times greater than that of piroxicam alone.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.4
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• pp.421-426
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• 2008

Freshly harvested seed of Chinese milk vetch (Astragalus sinicus L.; CMV) was strongly dormant because of hardseedness. Seeds of freshly harvested germinated only 8% while clipping the seed coat completely overcome the innate dormancy, which indicates inhibition of germination of the seed is mainly due to seed coat (87%). The dormant (intact) hard seeds did not imbibe water whereas the non-dormant (clipped) seeds took up rapidly. In natural environment condition, the hard seed coat dormancy was broken only after 5 months after seed harvest. To break such a strong seed coat dormancy, the chemical and heat treatments were effective. Concentrated sulfuric acid was more effective than dry heat and hot water treatments. Hot water treatment improved germination but the germination percentage was less than 41%. Treatments increased germination due to its effect on the seed coat integrity. A scanning electron microscope reveled that disruption of seed coat layers and subsequent development of numerous crack in the hilum region of the seed and on the seed coat surface of concentrated sulfuric acid treatment and formation of cracks in the dry heat treatments, respectively, were observed in the seed coat surface, which served as water entry points.

• Korean Journal of Veterinary Service
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• v.45 no.4
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• pp.277-284
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• 2022

Salmonella is a pathogenic bacterium that has long been important industrially because it has a wide host range and can be transmitted to humans through direct contact as well as indirect contact such as food contaminated with animal waste. Understanding how to reduce Salmonella contamination in pig farms is important for public health and the livestock industry from an economic perspective. In the swine industry, high concentrations of disinfectants have been applied because it is difficult to effectively control Salmonella in environments contaminated with organic substances. In order to evaluate the synergetic effect of disinfectants, the efficacy of two commercial disinfectants diluted in hard water and microbubble water (MBW) were compared under the laboratory condition. Different concentrations of both disinfectants combined with 1% detergent diluted in the two diluents were evaluated for their antibacterial effect. In the case of monopersulfate-based disinfectant groups, the growth of Salmonella was not observed at 1:200 dilution with both the hard water and MBW combined with 1% detergent. In the case of citric acid-based disinfectant, the bacterial growth was not observed at 1:800 dilution with MBW combined with 1% detergent. Our results show that the use of MBW as a diluent might improve the biological activities of acid-based disinfectant.

• Journal of the Korean Institute of Landscape Architecture
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• v.32 no.5
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• pp.43-51
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• 2004

Recently, the importance of choosing correct pavement materials has been increasing in urban spaces and streets. Much research regarding the pavement theory and construction method have been conducted, but analysis in terms of human psychological character has not yet been performed. The purpose of this study is to investigate the psychological characters to 12 pavement materials, that are commonly used in our urban spaces and streets. The results of the psychological character for each pavement material can be summarized as follows: 1. The psychological characters to each pavement material were as follows: ① Clay embodies a natural, traditional, soft and intimate psychological character; ② Pebble stone has a natural, hard, cool and intimate psychological character; ③ Turf grass incorporates an intimate and soft psychological character; ④ Ceramic brick has an artificial and hard psychological character; ⑤ Tile pavement has a modern, artificial, hard and cool psychological character; ⑥ Water permeable concrete has a modern and artificial psychological character; ⑦ Flag stone has a natural psychological character; ⑧ Granite has a modern and artificial psychological character; ⑨ Portland concrete has an artificial and hard psychological character; ⑩ Small compacted brick has an artificial, dynamic and modern psychological character; ⑪ Wood block pavement has a natural and traditional psychological character; ⑫ Asphalt concrete pavement has a modern, hard and artificial character. 2. On the results of the cluster analysis regarding psychological indexes for 12 pavement materials, pavement materials were categorized in 3 clusters. Among them, one cluster was mainly used as the most popular pavement material in our urban spaces and streets. From this point of view, psychological character for pavement material in our urban spaces and streets was not as various as we expected. 3. In conclusion, the proper selection of pavement materials was very important and the factors affecting the human psychological character should be considered in the design of urban spaces and streets.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.8
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• pp.2073-2080
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• 1994

In this paper, a model of material removal in abrasive water jet machining of brittle material is developed, and experimentally evaluated. Abrasive water jet machining proved to yield better material removal rate than other machining techniques for hard and brittle material (alumina ceramics). It was also found that large scale fracture may develop at the exit of the jet from the material. The fracture size was predicted as a function of water jet pressure and size of the hole. Finally, the feasibility of using acoustic emission signals for in-process monitoring of the abrasive water jet machining process is investigated.

• Proceedings of the KIEE Conference
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• 1997.07a
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• pp.149-151
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• 1997

Korea Water Resources Corporation (KOWACO) has used hard wired sequential control system for dams and SCADA / DCS for water supply offices. The control system, which consists of automatic control, communication and computer science, has to look for the security of operation and the quality of generated power and treated water. In this paper, we would like to propose the systematic evaluation of technical proposals such as purpose, method/procedure, evaluation criteria and report preparation.

• Food Science and Preservation
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• v.13 no.2
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• pp.259-268
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• 2006

We investigated food preservation hurdles used for Korean traditional side dishes. As a first step of the research preparation and cooking recipes of the side dishes were surveyed, which are commonly used in Korean households. As next step, compositional and microbial quality attributes were measured onto the samples collected from the market. Antimicrobial ingredient added in the preparation are reasoned to work as important hurdles based on the scientific principles. Heating processes such as blanching, boiling, braising, hard-boiling and frying help to keep the produce decontamination or water activity adjustment. Measured salt contents of most side dishes were in the range of 1-5% with those of salt-preserved vegetables being higher. pH values were 4.7-6.4 with those of salt-preserved vegetables being lower and those of hard boiled fishes being higher. Soluble solids of braised or hard-boiled dishes were usually above $40^{\circ}Brix$, while those of blanched and seasoned vegetables had lower values. Water activity values were 0.93-0.95 for seasoned vegetables and 0.77-0.88 for hard-boiled or semi dried beans and seafoods. Product with processing steps of braising or blanching showed lower bacterial load of 102-104 cfu/g, while seasoned or salt-preserved vegetables and seafoods had aerobic bacterial count above 106 cfu/g. Korean traditional side dishes were found to apply the appropriate combinations of heating preparation process, water activity and pH adjustment and salting, providing the required preservation properties.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.69-72
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• 2004

There are an electronic and a manual type in Bidet. The electronic bidet has some advantages. it supplies multiple functions and is up easily. However, it has frequent defects and a high price. The manual bidet is not need to supply electric and is cheaper than the electronic type. However, it is needed to supply hot water and is hard to set up. In order to solve these defects, this study designed a bidet heating unit using an electric instantaneous water heating method. To get a proper heating elements, experiments were performed about a Ni-Cr heater and a film heater.