• Applied Chemistry for Engineering
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• v.19 no.4
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• pp.445-451
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• 2008

In order to regenerate the activated carbon polluted by volatile organic compounds (VOCs) using microwave, adsorption and desorption characteristics of benzene over activated carbon (AC) coated with insulating materials were investigated. Physical characteristics of activated carbon and insulator-coated ACs were investigated by means of $N_2$ gas adsorption and scanning electron microscopy (SEM). The amount of VOC adsorbed showed a positive relationship with the specific surface area of the ACs, and spark discharge over insulator-coated ACs did not occur. Potassium silicate (PS) was the best binder for coating of insulating materials on AC. Amount of benzene desorbed by microwave irradiation was dependent on output power of microwave. Nearly same performance was obtained even though the adsorption-desorption operation under microwave irradiation was repeated 5 times. Finally, it was known that the microwave heating was a very effective mean for regenerating the polluted AC.

• Korean Journal of Plant Resources
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• v.29 no.3
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• pp.347-354
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• 2016

The present study was performed to investigate the effects of the colchicine concentrations on chromosome doubling for producing of tetraploid plants of Codonopsis lanceolata, and its effect on plant morphology. A total of 180 individuals germinated from 16 treatment groups, were exposed to various concentrations (0.05-1.0% w/v) of colchicine for different soaking duration (3-24 hour). The highest numbers of tetraploid plants (3) were observed from the lowest concentration of colchicine (0.05%), and one (1) tetraploid plant was obtained from the 0.5% concentration group with a 6 hour treatment. However, no tetraploid individual was observed in any other treatment groups. The plant height of the diploid (18.1 ㎝) was slightly shorter than that of the tetraploid (13.4 ㎝). The fresh weight of the main root in the diploid (0.5 g) was four-fold higher than the tetraploid (2.2 g). The colchicine-treated plant regeneration rate in C. lanceolata was decreased when the plants were subjected to high concentration of colchicine. In particular, the highest number of tetraploid plants (5 and 3) was obtained from the lower concentration (0.05% and 0.1%) of colchicine for 6-hour treatment, which were a higher rate (29.4% and 30%) of regenerated tetraploid plants than other regenerated plants. As in the seed treatment result, the plant height of the diploid was significantly higher (10.4 ㎝) than tetraploid. The higher morphological changes were observed comparatively from tetraploid plants than the diploid.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.8
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• pp.815-823
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• 2011

Combustion phenomena in porous media combustors are widely used in industrial fields for the combustion of lowgrade fuels and the regeneration of combustion heat. However, studies of combustion phenomena in porous media have been limited, because these phenomena are difficult to observe, and the configurations of porous media are complex. We propose a simple model combustor: a multi-channel combustor that consists of many layers of combustion channels made of quartz plates. We conducted an experimental observation of the flames in the multi-channel combustor and obtained experimental results for the flame stabilization limits. Flames formulated in the multi-channel combustor showed variation in the spatial distribution depending on the heat transfer between neighboring channels. A simple analytical model was developed and the variation in the flammability limits of the multi-channel combustor was discussed. This study will enhance our understanding of flame behavior in a porous-media combustor.

• Korean Journal of Medicinal Crop Science
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• v.25 no.6
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• pp.404-410
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• 2017

Background: Hair loss related syndromes are increasing due to environmental pollution and stress. Hair care products are mainly prepared by mixing chemicals and natural extracts, such as those obtained from medicinal plants. The purpose of this study was to investigate the effects of 70% ethanol extracts from the flowers of Calendula officinalis, fruit body of Phellinus linteus, and the whole plant of Houttuynia cordata on the growth of CCD-986 cells, hair follicle dermal papilla cells (HFDPC), and 3T3-L1 cells. Methods and Results: All sample extracts at all concentrations, except for that from P. linteus fruit body at $500{\mu}g/m{\ell}$, were cytotoxic to CCD-986 cells. However, none of the sample extracts were cytotoxic to HFDPC. The lipid differentiation of 3T3-L1 cells regulates hair regeneration via secretion of platelet derived growth factor. The 70% ethanol extract of H. cordata whole plant promoted hair growth. Adipogenesis rate significantly increased in a treatment concentration-dependent manner. Conclusions: These results suggest that 70% ethanol extracts of C. officinalis flower, P. linteus fruit body and H. cordata could be used for the development of hair care products.

• Food Engineering Progress
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• v.21 no.3
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• pp.233-241
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• 2017

Scaffolds of cell substrates are biophysical platforms for cell attachment, proliferation, and differentiation. They ultimately play a leading-edge role in the regeneration of tissues. Recent studies have shown the potential of bioactive scaffolds (i.e., osteo-inductive) through 3D printing. In this study, rice bran-derived biocomposite was fabricated for fused deposition modeling (FDM)-based 3D printing as a potential bone-graft analogue. Rice bran by-product was blended with poly caprolactone (PCL), a synthetic commercial biodegradable polymer. An extruder with extrusion process molding was adopted to manufacture the newly blended "green material." Processing conditions affected the performance of these blends. Bio-filament composite was characterized using field emission scanning electron microscopy (FE-SEM) and energy dispersive X-ray spectroscopy (EDX). Mechanical characterization of bio-filament composite was carried out to determine stress-strain and compressive strength. Biological behaviors of bio-filament composites were also investigated by assessing cell cytotoxicity and water contact angle. EDX results of bio-filament composites indicated the presence of organic compounds. These bio-filament composites were found to have higher tensile strength than conventional PCL filament. They exhibited positive response in cytotoxicity. Biological analysis revealed better compatibility of r-PCL with rice bran. Such rice bran blended bio-filament composite was found to have higher elongation and strength compared to control PCL.

• The Journal of the Convergence on Culture Technology
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• v.7 no.1
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• pp.327-335
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• 2021

We aimed to find new space types and characteristics for creating gardens in the city through the type of idle space in the city, present guidelines that can be used in creating gardens in the future, and establish basic data for expanding green infrastructure. As a result, we found that the idle space in the city was classified into four types, and it was determined that differentiation should be given to the creation of each type. The achievements of this study can be a potential source of urban ecosystem services that can provide community benefits and opportunities for urban regeneration through the redevelopment of the community and support the health and well-being of local residents. In addition, urban idle space can be a valuable resource as a green infrastructure that can be used to support the health of urban ecosystems and improve the quality of life of urban residents.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.32 no.1
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• pp.1-9
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• 2022

Objectives: The purpose of this study is to evaluate exposure characteristics of lead using data from the domestic occupational exposure literature. Methods: Occupational airborne exposure data on lead reported in the domestic literature from 1981 to 2018 were collected and re-analyzed. The exposure levels in the data were expressed as an estimated arithmetic mean and a weighted arithmetic mean (WAM) of the number of samples. Lead exposure characteristics were analyzed by industry, process, and year. Results: From a total of 14 documents, 8,305 airborne lead measurements for 17 industries were identified, and the WAM concentration in eight industries exceeded the occupational exposure limit of 50 ㎍/m³. Three industries (battery manufacturing, lead smelting, and litharge manufacturing) accounted for 95% of the total data, and exposure trends could be confirmed over 10 years. Exposure levels continue to decrease in all three industries. Conclusions: Considering the distribution outlook of lead and lead compounds, the main management targets are lead storage battery manufacturing and secondary smelting for lead regeneration.

• Applied Chemistry for Engineering
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• v.33 no.5
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• pp.482-487
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• 2022

In this study, the activity test and characterization were performed to evaluate the hydrogen sulfide removal characteristics using a V/TiO₂ catalyst at room temperature. The optimal vanadium loading was 10 wt%, and the durability was greater than 60 minutes at 60~80% relative humidity. The Brunauer-Emmett-Teller (BET) surface area and raman spectroscopy results confirmed that the structure of the vanadium site exposed to the surface was a dominant factor in catalyst activity. From Scanning Electron Microscope (SEM), Energy Dispersive Spectroscopy (EDS) and X-ray crystallography (XRD) analyses, it was found that sulfur can be accumulated on the catalyst surface, which results in a decrease in durability under catalytic activity tests. Therefore, it is judged that a combined process of catalytic oxidation and regeneration is needed.

• Journal of the Society of Disaster Information
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• v.19 no.4
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• pp.815-825
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• 2023

Purpose: This paper aims to explore approaches for obtaining KOLAS certification for masks developed as protective equipment for use during evacuation processes in the event of a radiation disaster involving residents within a radiation emergency planning zone. Method: Various reports, papers, and data from the KOLAS accreditation bodies' websites were examined for this study. Result: Although domestic radiation disaster preparedness measures have been established to enhance resident protection, the distribution of protective equipment is limited to thyroid protection drugs. Supplementary support items like masks are necessary to prepare for radiation disasters. Currently, there is no KOLAS-accredited certification body for radiation protection masks. Conclusion: For masks that have established performance certification criteria, a dual process is required for KOLAS certification. This involves obtaining an official test report as an industrial respirator mask, receiving certification, and then obtaining a general test report based on internal standards.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.11
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• pp.309-316
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• 2020

This study analyzed Japan's three-dimensional road system as part of a study on urban regeneration plans through the three-dimensional use of road space. The three-dimensional road system integrates the Road Act, Urban Planning Act, and the Building Standard Act. The advantage of the three-dimensional road system is that landowners can freely use the space above and below the road so that they can live and operate sustainably, and road managers have the advantage of reducing the land acquisition costs because they only acquire rights to the road. In terms of type, it is applied to a variety of integrated and separated structures in elevated roads, underpasses, free passages, parking lots, and monorails. In addition, in the case of development methods, the degree of freedom of development plans is improved by enabling integrated maintenance of roads and buildings. Management stability is improved by applying management and law-based authority according to the Road Act. In this way, the three-dimensional road system provides support to maximize the use of limited available land through the three-dimensional use of road space, and to develop sustainable and good urban areas in development areas.