• Composites Research
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• v.35 no.2
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• pp.98-105
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• 2022

In this study, polyvinyl alcohol (PVA)/graphene oxide (GO)/iron oxide (Fe₃O₄) magnetic microgels were prepared using a microfluidic approach and the dye adsorption capacity of the microgels was confirmed. The adsorption capacity (q_e) of the gels was evaluated by varying the dye concentration, pH, and contact time with the microgels. The dyes used in this work were methylene blue (MB), crystal violet (CV), and malachite green (MG), and microgels showed the highest adsorption capacity (191.1 mg/g) in methylene blue. The microgels exhibited the highest adsorption capacity in the dye aqueous solution at pH 10 due to the presence of atomic nitrogen ions (N⁺) on the dye molecules. The adsorption isotherm studies revealed that the Langmuir isotherm is the best fit isotherm model for the dye adsorption on the microgels, indicative of monolayer adsorption. The kinetic analysis exhibited that the pseudo-second order model fits better than the pseudo-first order model, confirming that the adsorption process is chemisorption. In addition, the magnetic microgels showed good reusability and recovery efficiency. It was confirmed that the adsorption capacity of the gels maintains more than 70% of the initial capacity after 5 times of cycle experiments.

• Journal of the Korean Applied Science and Technology
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• v.39 no.3
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• pp.471-478
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• 2022

This study attempted to find out the improvement effect the improvement effect of Babassu oil on damaged hair by damaged hair by applying a hair-improving formulation with Babassu oil to damaged hair after manufacturing. As the experimental raw material, the contents of babassu oil were changed to 0 g, 3 g 6 g, and 9 g and added to the perm base agent. The prepared formulation was applied to 8 levels of bleached sample hair. Each sample and damaged hair were measured and compared and analyzed. As for the measurement method, tensile strength, absorbance using methylene blue, and gloss were measured to know the effect of improving damage hair Statistical analysis was conducted for the reliability of the research results. As a result of the research, it was found that the tensile strength was higher than that of the damaged hair in all samples applied by adding babassu oil. As a result of absorbance analysis using methylene blue, it was found that absorbance was decreased in all samples compared to damaged hair. As a result of the gloss measurement, it was found that the gloss was increased in all samples compared to the damaged hair. In conclusion, it was found that babassu oil had an improvement effect on damaged hair.

• Applied Chemistry for Engineering
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• v.33 no.2
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• pp.159-165
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• 2022

To enhance the photocatalytic activities of WO₃ photocatalysts, fluorine doping was performed to induce the oxygen vacancies. Both plasma and direct vaper fluorination were carried out for fluorine doping, and photocatalytic activities were examined by using methylene blue dye. Oxygen vacancies of the plasma and direct vaper fluorinated WO₃ photocatalysts were measured to be 14.65 and 18.59%, which increased to about 23 and 56% at pristine WO₃ photocatalysts. The degradation efficiency of methylene blue was also determined about 1.7 and 3.4 times higher than pristine WO₃ photocatalysts, respectively, depending on oxygen vacancies increased. In addition, it was confirmed that the bandgap process energy decreased from 2.95 eV to 2.64 and 2.45 eV after fluorine doping. From this result, it is considered that the direct vaper fluorination has an advantage for increasing the photocatalytic activities of WO₃ compared to that of the plasma fluorination.

• Korean Journal of Environmental Biology
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• v.41 no.2
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• pp.101-108
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• 2023

Recently, in relation to climate change, many studies have been conducted to predict the potential habitat area and distribution range of tilapia and the suitability of habitat for each species. Most tilapia are tropical fish that cannot survive at water temperatures below 10 to 12℃, although some tilapia can survive at 6 to 8℃. This study predicted habitable areas and the possibility of spreading of habitat ranges of tilapia (Oreochromis niloticus and Oreochromis aureus) known to inhabit domestic streams. Due to climate change, it was found that habitats in the Geum River, Mangyeong River, Dongjin River, Seomjin River, Taehwa River, Hyeongsan River, and the flowing in East Sea were possible by 2050. In addition, it was confirmed that tilapia could inhabit the preferred lentic ecosystem such as Tamjin Lake, Naju Lake, Juam Lake, Sangsa Lake, Jinyang Lake, Junam Reservoir, and Hoedong Reservoir. In particular, in the case of tilapia, which lives in tributaries of the Geumho River, Dalseo Stream, and the Nakdong River, its range of habitat is expected to expand to the middle and lower of the Nakdong River system. Therefore, it is judged that it is necessary to prepare physical and institutional management measures to prevent the spread of the local population where tilapia currently inhabits and to prevent introduction to new habitats.

• Journal of the Korea Society of Computer and Information
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• v.28 no.8
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• pp.103-109
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• 2023

In this paper, we propose a smart wall switch based on IEEE 802.11b/g/n standard 2.4GHz band communication. As the 4th industrial era evolves, smart home solution development is actively underway, and application cases for smart wall switches are increasing. Most of the Chinese products that preoccupy the market through price competitiveness use Bluetooth and Zigbee communication switches. However, while ZigBee communication is low power, communication speed is slower than Bluetooth and network configuration through a separate hub is additionally required. The Bluetooth method has problems in that the communication range and speed are lower than Wi-Fi communication, the communication standby time is relatively long, and security is weak. In this study, an IEEE 802.11b/g/n smart wall switch applied with Wi-Fi communication technology was developed. In addition, through the two-wire structure, it is designed so that no additional cost is incurred through the construction of a separate neutral line in the building. The result of the study is more than 30% cheaper than the existing wall switch, so it is judged that it will be able to preoccupy the market not only in terms of technological competitiveness but also price competitiveness.

• Journal of the Korean Society of Floral Art and Design
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• no.37
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• pp.157-166
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• 2017

To select fruit trees for urban garden with Elaeagnus umbellata var. coreana, Malus domestica 'Alps Otome', Prunus mume, Ribes nigrum, Rubus fructicosus, and Vaccinium corymbosum 'Reka', growth characteristics of these 6 species were compared and effect of trickle irrigation and shading on the growth of these fruit trees were investigated that these treatments were carried out how much these trees are endurable exposed to improper conditions. After passing the winter, E. umbellata var. coreana, M. domestica 'Alps Otome', P. mume, and V. corymbosum 'Reka' showed the highest survival rate, in contrast to R. nigrum with the lowest of 56.0%. In 9 months after planting, the hight growth rate of 62.3% was shown in P. mume but that of E. umbellata var. coreana was stagnant during experimental period. Flowering rate over 80.0% were shown in E. umbellata var. coreana, M. domestica 'Alps Otome', R. fructicosus, and V. corymbosum 'Reka'. On the other hand, R. nigrum has not ever flowering branches. Other species except E. umbellata var. coreana and R. nigrum have about 10 days in flowering duration. After flowering, fruition rate has shown significant difference among 6 species. As a result of both treatment of trickle irrigation and shading, leaf area and leaf weight of E. umbellata var. coreana, M. domestica 'Alps Otome' significantly inceased with treatments that have not affected other species. Based on these result, it is possible to deploy suitable fruit trees to specific garden condition after selecting various fruit trees.

• Journal of Dairy Science and Biotechnology
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• v.41 no.4
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• pp.191-202
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• 2023

In this study, lactic acid bacteria (LAB) was isolated from blueberries. The isolated LAB were rod-shaped and gram-positive, as shown using gram staining. In addition, the identified bacteria showed high homology to Lactiplantibacillus argentoratensis. The culture supernatant was isolated from L. argentoratensis and its antibacterial activity against the pathogenic bacteria Salmonella and Escherichia was analyzed. Culture supernatants of L. argentoratensis significantly inhibited the growth of Salmonella. Enteritidis NCCP 16947, Salmonella Typhimurium NCCP 16960, and Salmonella. Thompson NCCP 11704. Interestingly, the higher the concentration of the culture supernatant, the more significant was the antibacterial activity. Additionally, the culture supernatant of L. argentoratensis showed significant antibacterial activity against Escherichia strains. To determine whether the antibacterial substance is stable to heat and pH, the LAB culture supernatant was heat-treated under 65℃ for 30 min, 75℃ for 15 min, 85℃ for 10 min, and 100℃ for 5 min. Measurement of antibacterial activity against pathogenic strains by adding 5% of heat-treated culture medium showed the same antibacterial activity as before heat treatment. However, in a test where the pH of the culture supernatant was adjusted to 7.0 from 3.73, no antibacterial activity was observed.

• Land and Housing Review
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• v.15 no.1
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• pp.167-177
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• 2024

This study aimed to assess the efficacy of an adsorption process in removing organic matter and micropollutant residuals. After a full-scale water circulation system, the adsorption process was considered a post-treatment step. The system, treating anthropogenically impacted surface waters, comprises a hydro-cyclone, coagulation, flocculation, and dissolved air flotation unit. While the system generally maintained stable and satisfactory effluent quality standards over months, it did not meet the highest standard for organic matter (as determined by chemical oxygen demands). Adsorption experiments utilized two granular activated carbon types, GAC 830 and GCN 830, derived from coal and coconut-shell feedstocks, respectively. The assessment encompassed organic materials along with two notable micropollutants: acetaminophen (APAP) and acid orange 7 (AO7). Adsorption kinetics and isotherm experiments were conducted to determine adsorption rates and maximum adsorption amounts. The quantitative findings derived from pseudo-second-order kinetics and Langmuir isotherm models suggest the effectiveness of the adsorption process. The findings of this study propose the potential of employing the adsorption process as a post-treatment to enhance the treatment of contaminants that are not satisfactorily treated by conventional water circulation systems. This enhancement is crucial for ensuring the sustainability of urban water cycles.

• Journal of Bio-Environment Control
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• v.32 no.4
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• pp.336-341
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• 2023

This study examines the characteristics of berries from secondary bearing shoots of 'Scintilla' southern highbush blueberry, grown hydroponically in the Jinju, Gimhae, and Uiryeong regions of Gyeongnam Province. Typically, 'Scintilla' forms flower buds at the tips of regular bearing shoots during the previous season, yielding berries in the current season. However, under heated cultivation, we observed a proliferation of secondary bearing shoots that produce berries in the same growing season. Flowering and harvesting on secondary bearing shoots were delayed by 52 and 36 days, respectively, compared to regular bearing shoots. However, these shoots exhibited a 54% increase in diameter and a 10% increase in length. We found no significant difference in berry size and soluble solid content between the two types of shoots. Notably, berries from the secondary bearing shoots had higher potassium and lower calcium and magnesium concentrations. We conclude that berries from secondary bearing shoots could be marketable, provided the bushes are healthy. These findings provide valuable insights for optimizing cultural practices to improve the yield and quality of blueberries under specific environmental conditions.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.05a
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• pp.69-72
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• 2008

In the paper, embedded system that manage, control the status of vehicle through internet and mobile instruments are designed. The network is composed of the distributed control system using CAN communication, where communication is possible with two lines, and the bluetooth, where wireless communication is possible. We also designed the Embedded system to make up the web server only for the vehicle, made it possible to catch hold of the conditions of the vehicle and control the vehicle through internet by interfacing the destributed controller. We also made such a Web Server possible th be monitored and controlled by the mobile instruments such as PDA, mobile phones.