• Applied Chemistry for Engineering
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• v.34 no.1
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• pp.36-44
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• 2023

Core-shell TiO₂/Ag nanoparticles were synthesized by a modified sol-gel process and the reverse micelle method using acetoxime as a reducing agent in water/dodecylbenzenesulfonic acid (DDBA)/cyclohexane. The structure, shape, and size of the TiO₂/Ag nanoparticles were investigated using X-ray diffraction (XRD), UV-visible spectroscopy, scanning electron microscope (SEM), transmission electron microscope (TEM), and thermogravimetric analysis (TGA). The size of TiO₂/Ag nanoparticles could be controlled by changing the [water]/[DDBA] molar ratio values. The size and the polydispersity of TiO₂/Ag nanoparticles increased when the [water]/[DDBA] molar ratio rose. The resultant Ag nanoparticles over the anatase crystal TiO₂ nanoparticles exhibited a strong surface plasmon resonance (SPR) peak at about 430 nm. The SPR peak shifted to the red side with the increase in nanoparticle size. Conductive pastes with 70 wt% TiO₂/Ag nanoparticles were prepared, and the pastes were coated on the PET films using a screen-printing method. The printed paste films of the TiO₂/Ag nanoparticles demonstrated greater surface resistance than conventional Ag paste in the range of 405~630 μΩ/sq.

• Economic and Environmental Geology
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• v.55 no.1
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• pp.29-43
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• 2022

The groundwater quality in Boseong area was characterized and their background concentrations were estimated based on the chemical data obtained from 200 groundwater samples collected during July 2019. Groundwater data were classified into two groups: Group 1 with NO₃^- < 44.3 mg/L and Group 2 with NO₃^- ≥ 44.3 mg/L. Results of t-tests indicate that groundwaters in Group 2 are significantly higher in water temperature and Ca concentration and significantly lower in F, As, Pb and Zn concentrations. It was also revealed that groundwaters Group 2 are closely linked to low pH, alkalinity, NH₄, NO₂, F, As, Fe, Mn, Pb and Zn levels, and high EC and water temperature. Background concentrations were estimated using the the BRIDGE method. The results depicted the higher levels in NO₃, NH₄, PO₄, As, Fe, Mn than the ones estimated by MOE and KECO (2018; 2019), which were prepared for the three catchment units in Boseong. The results of this study are believed to have more reliability because more data were used.

• 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 Institute of Landscape Architecture
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• v.50 no.1
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• pp.20-32
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• 2022

For this study, 313 pedestrians, including students, from two schools participated in the greening project of the school commuting roads in Seoul. These schools were compared to two without street greenspaces to analyze the effects of the green areas on pedestrian satisfaction and the future direction of creation. As a result of the greenspace satisfaction analysis of schools with greenspace, the items that had the greatest effect on overall satisfaction were 'Width of the sidewalk' (37%), 'Harmony with the surrounding landscape' (24.97%), 'The arrangement of trees, grass, and flowers' (18.30%) and 'Overall management' (10.44%). In other words, the item that satisfies most is securing the appropriate width of the sidewalk where the greenspace is located. It is necessary to re-considered creating greenspaces in existing sidewalk spaces and secure a sidewalk width for pedestrian convenience. As a result of the analysis on the direction of greenspace creation, the respondents who experienced greenspaces through the greenspaces on school commuting routes recognized natural features, such as grass and flowers as more important elements as well as noting that landscape and harmony are important. In addition, respondents interested focusing on functionality recognized the need for greenspaces and highly recognized the importance of arranging natural materials, such as trees, grasses, and flowers. This group also recognized the advantages of functionality and the effectiveness of green spaces. Therefore, it is necessary to expand awareness of the effectiveness of greenspaces through environmental education, publicity, and the provision of information boards. More effort will be needed to apply regional and school characteristics rather than uniform composition to the development of greenspaces.

• The Journal of Engineering Geology
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• v.32 no.4
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• pp.627-642
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• 2022

The world's long reliance on fossil fuels (e.g., oil, coal, and natural gas) is severely changing its environment and climate. Energy research has focused on developing hydrogen as the most promising energy carrier and a key technology for sustainable energy development. Hydrogen can be classified as gray, blue, green, and otherwise according to the raw materials and methods used for production and processing. For the development of hydrogen energy, geologists are attempting to identify the mechanism of abiotic hydrogen generation by serpentinization or hydrothermal alteration. Teams in the United States, France, and Australia have researched laboratory-scale hydrogen production through water-rock interactions under various conditions, whereas there has been almost no research on abiotic hydrogen in South Korea. This paper reviews the current state of international research on hydrothermal alteration and offers suggestions for future investigations of abiotic hydrogen production in South Korea.

• Journal of Life Science
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• v.32 no.2
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• pp.148-154
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• 2022

Focal adhesion kinase (FAK) is known to regulate cell adhesion, migration, and mechanotransduction in focal adhesions (FAs). However, studies on how FAK activity is regulated in the plasma membrane microdomains according to the composition of extracellular matrix (ECM) proteins are still lacking. A genetically encoded fluorescence resonance energy transfer (FRET)-based biosensor can provide useful information on the activity of intracellular signals with high spatiotemporal resolution. In this study, we analyzed the FAK activities in lipid raft (detergent-resistant membrane) and non-lipid raft (non-detergent-resistant membrane) microdomains using FRET-based membrane targeting FAK biosensors (FAK-Lyn and FAK-KRas biosensors) under four different ECM protein compositions: glass, type 1 collagen, fibronectin, and laminin. Interestingly, FAK activity in response to laminin in a lipid raft microdomain was lower than that in other ECM conditions. Cells subjected to fibronectin showed higher FAK activity in a lipid raft microdomain than that in a non-lipid raft microdomain. Therefore, this study demonstrates that the FAK activity can be distinctively regulated according to the ECM type and the environment of the plasma membrane microdomains.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.25 no.4
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• pp.15-31
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• 2022

The Green Purification Unit System (GPUS) is a green infrastructure facility applicable to the roadside to reduce particulate matter from road traffic. This study introduces two types of GPUS (type1 and type2) and assesses the performance and maintenance costs of each of them. The GPUS's performance analysis used the data collected in November 2021 after the installation of the GPUS type1 and type2 at the study site in Suwon. The changes in the particulate matter concentration near the GPUS were measured. The maintenance cost of GPUS type1 and type2 was assessed by calculating the initial installation cost and the management and repair cost after installation. The results of the performance analysis showed that the GPUS type1, which was manufactured by combining plants and electric dust collectors, had a superior particulate matter reduction performance. In particular, type1 produced a greater effect of particulate matter reduction in the time with a high concentration (50㎍/m³ or higher) of particulate matter due to the operation of electric dust collectors. GPUS type2, which was designed in the form of a plant wall without applying an electric dust collector, showed lower reduction performance than type1 but showed sufficiently improved performance compared to the existing band green area. Meanwhile, the GPUS type1 had three times higher costs for the initial installation than GPUS type2. In terms of costs for managing and repairing, it was evaluated that type1 would be slightly more costly than type2. Finally, this study discussed the applicability of two types of GPUS based on the result of the analysis of their particulate matter performance and maintenance cost at the same time. Since GPUS type2 has a cheaper cost than type1, it could be more economical. However, in the area suffering a high concentration of particulate matter, GPUS type1 would be more effective than type2. Therefore, the choice of GPUS types should rely on the status of particulate matter concentration in the area where GPUS is being installed.

• Clean Technology
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• v.28 no.3
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• pp.249-257
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• 2022

The adsorption equilibria of nitrogen on a region of nanoporous carbonaceous adsorbent with local molecular orientation (LMO) were calculated by grand canonical Monte Carlo simulation at 77.16 K. Regions of LMO of identical size were arranged on a regular lattice with uniform spacing. Microporosity was predominately introduced to the model by removing successive out-of-plane domains from the regions of LMO and tilting pores were generated by tilting the basic structure units. This pore structure is a more realistic model than slit-shaped pores for studying adsorption in nanoporous carbon adsorbents. Their porosities, surface areas, and pore size distributions according to constrained nonlinear optimization were also reported. The adsorption in slit shaped pores was also reported for reference. In the slit shaped pores, a clear hysteresis loop was observed in pores of greater than 5 times the nitrogen molecule size, and in capillary condensation and reverse condensation, evaporation occurred immediately at one pressure. In the LMO pore model, three series of local condensations at the basal slip plane, armchair slip plane and interconnected channel were observed during adsorption at pore sizes greater than about 6 times the nitrogen molecular size. In the hysteresis loop, on the other hand, evaporation occurred at one or two pressures during desorption.

• The Journal of Sustainable Design and Educational Environment Research
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• v.21 no.1
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• pp.11-23
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• 2022

The purpose of this study is to develop the Korean New Deal policy in the post-corona era, and furthermore, to provide basic data to discover and present a desirable future educational facility environment-related agenda that will help the successful realization of the policy. In order to achieve the above research purpose, we explored the new paradigm shift for the education new deal in the post-COVID-19 era and the future educational facility environment through Korean and overseas related policies, reports, and source books. And a Delphi survey was conducted on panels of experts in the front-line education field, academia, and industry. As a result, 5 areas were derived as key domains of the educational facility environment in the post-COVID-19 era, and a total of 33 agendas [8 in green, 9 in smart, 9 in spatial innovation, 4 in school facilities complexation, and 3 in others (safety)] were derived. The study findings confirmed that the demand for the smart area and spatial innovation area as the educational facility environment agenda in the post-COVID-19 era was relatively high compared to the green area or school facilities complexation area. Therefore, when establishing educational facility policies in the future, it is necessary to establish customized policies that reflect the demands and needs for the smart area and spatial innovation area, whereas it is necessary to focus more on establishing policies that improve awareness and interest about the green area and school facilities complexation area.

• Journal of Wetlands Research
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• v.24 no.3
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• pp.170-184
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• 2022

The Riparian Buffer Zone(RBZ) is a sustainable social-ecological system created in the middle zone between water and land. For the RBZ, close communication with the local community is important, and it is necessary to promote it as a communicative environmental planning process. In this study, for the RBZ project, three strategies are presented as a communicative act to understand and implement planning. First, government-led projects were avoided and improved to a process in which citizens and stakeholders participated together, centered on local partnership. Second, it was intended to introduce design criterias in terms of enhancing the function of ecosystem services that citizens can sympathize with, and to increase acceptance and awareness through the planning of preferred spaces and facilities. Third, after a balanced plan for habitats, water cycle-based ecological environment, ecological experience and open space, citizens felt the restoration effect and value as an ecological resources, and a system was prepared to participate in the operation and management. This study will work as a process model based on citizens's participation. In addition, it will be possible to provide lessons for the change of the policy paradigm for the RBZ and the implementation of similar projects in the future.