• Journal of the Korean Wood Science and Technology
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• v.44 no.5
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• pp.785-808
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• 2016

The objective of this study was to investigate the effect of the short-term weathering on the flame retardant performance of wood coated with Dancheong. Flame retardants were applied on the Dancheong coated Korean red pine. Flame retardants applied panels were layed at the two conditions of outdoor exposure and artificial aging to assess the reliability of artificial aging. Flame retardants used were commercial products developed for historical wooden buildings. Scanning electron micrographs revealed the forming of carbonized membrane by melting of flame retardant on wood surface. These carbonized membranes may help delay the further combustion of wood. Flame retardant performance was assessed by measuring heat release rate (HRR) and total heat release (THR) by cone calorimetry. There was no difference in flame retardant performance between before and after 6-month outdoor exposure tests. And also no difference in flame retardant performance between before and after 2-week artificial aging which corresponds to 6-month outdoor exposure. Both tests showed the similar results of combustion characteristics.

• Journal of Life Science
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• v.21 no.5
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• pp.734-738
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• 2011

Aging in humans is inexorable and inescapable. The progressive decrease of physiological capacity and the reduction of the ability to cope with environmental stresses lead to increased susceptibility and vulnerability to human disease. Recently, in the cosmetic industry, many researchers have paid considerable attention to delaying or improving the symptoms of skin aging. Since the early 1990`s, there have been various challenges in developing cosmeceutical products which have strong anti-aging effects, and this has been an important issue in the cosmetic industry. Meanwhile, development of anti-aging cosmetics supported by biochemical activities in the skin has been researched. Castanea crenata inner Shell solvent extracts were investigated for anti-wrinkle and whitening effects, in order to apply it as a functional ingredient for cosmetic products. For anti-wrinkle effect, elastase inhibition activity of Castanea crenata inner shell acetone extract (CA) was 51.0% at a concentration of 100 ug/ml. The collagenase inhibition activity of CA and Castanea crenata inner shell ethanol extract (CE) was 96.4%, 94.3% at a concentration of 50 ug/ml. The tyrosinase inhibitory effect, which is related to skin-whitening, was 47.2% and 45.8% in CA and CE at a concentration of 500 ug/ml. All these results suggest that Castanea crenata inner shell can be effectively used as a cosmeceutical ingredient for the prevention of wrinkles.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.6
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• pp.3799-3804
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• 2014

In sea water, microalgae are exposed to a range of critical environmental conditions. Microalgae are protected from UV-A radiation due to the presence of mycosporine like amino acids(MAAs). Owing to the UV-A absorption properties of MAAs, they are used widely as a UV protecting ingredient in cosmetics. Therefore, there is a need to increase the production yield of MAAs. This study investigated the production yield of MAAs in transformed microalgae by radiofrequency(RF) exposure. Initially, the Glut-1 gene was transformed to Chlamydomonas hedleyi microalgae as a glucose transporter. The biomass was enhanced after Glut-1 gene transformation. In addition, the MAAs production yield was increased during large scale production in bioreactors due to the RF treatment. Therefore, purified extracts of MAAs can be used as a sun block material in the cosmetic industrial field.

• Journal of Environmental Policy
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• v.13 no.2
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• pp.99-129
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• 2014

This research estimates the impact of population aging on energy use and carbon emissions by energy sources and by industrial sectors in Korea until 2035. For the estimation, the structural change in household consumption expenditure identified by the age-specific consumption pattern was analyzed in conjunction with energy and environment input-output tables. The estimation result presents that, despite the population aging, energy use and carbon emissions induced by household consumption continue to increase until 2026, and then that elevated levels of energy use and carbon emissions will be maintained for a considerable period of time. According to the estimation by energy sources, the use of natural gas will show substantial increase while the use of crude oil will switch to a downturn at a relatively early period. According to the estimation by industrial sectors, carbon emissions in the sectors with relatively high consumption share of old households such as medical health, dwelling, lighting, heating, air-conditioning, and food will have substantial increase, whereas those in the sectors associated with education, transport, catering, and accommodation services will turn downward relatively early. In addition, the study analyzes through policy simulation the impact of aging-related policy similar to the basic pension system, which is recently being discussed for legislation, on energy use and carbon emissions.

• Korean Journal of Environmental Agriculture
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• v.14 no.2
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• pp.202-212
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• 1995

In order to elucidate the degrading characteristics of the pyrethroid acaricide-insecticide, acrinathrin in two different types of soils, Soil A(pH, 5.8; organic matter, 3.4%; C.E.C., 115 mmol(+)/kg soil; texture, sandy loam) and Soil B(pH, 5.7; organic matter, 2.0%; C.E.C., 71 mmol(+)/kg soil; texture, sandy loam), residualities of the non-labeled compound under the field and laboratory conditions, extractability with organic solvents and formation of non-extractable bound residues, and degradabilities of [$^{14}C$]acrinathrin as a function of aging temperature and aging period were investigated. The half lives of acrinathrin in Soil A treated once and twice were about 18 and 22 days and in Soil B about 13 and 15 days, respectively, in the field, whereas, in the laboratory, those in Soil A and B were about 36 and 18 days, respectively, suggesting that the compound would be non-persistent in the environment. The amounts of $^{14}CO_2$ evolved from [$^{14}C$]acrinathrin in Soil A and B during the aging period of 24 weeks were 81 and 62%, respectively, of the originally applied $^{14}C$ activity, and those of the non-extractable soil-bound residues of [$^{14}C$]acrinathrin were about 70% of the total $^{14}C$ activity remaining in both soils, increasing gradually with the aging period. Degradation of [$^{14}C$]acrinathrin in both soils increased with the aging temperature. Three degradation products of m/z 198(3-phenoxy benzaldehyde), m/z 214(3-phenoxybenzoic acid), and m/z 228(methyl 3-phenoxybenzoate) as well as an unknown were detected by autoradiography of acetone extracts of both soils treated with [$^{14}C$]acrinathrin and aged for 15, 30, 60, 90, 120, and 150 days, respectively, and the degradation pattern of acrinathrin was identical in both soils. Acrinathrin in soil turned out to be degraded to 3-phenoxybenzaldehyde cyanohydrin by hydrolytic cleavage of the ester linkage adjacent to the $^{14}C$ with a cyano group, the removal of hydrogen cyanide therefrom led to the formation of 3-phenoxybenzaldehyde as one of the major products, and the subsequent oxidation of the aldehyde to 3-phenoxybenzoic acid, followed by decarboxylation would lead to the evolution of $^{14}CO_2$.

• Journal of Soil and Groundwater Environment
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• v.25 no.2
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• pp.9-15
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• 2020

This study was conducted to investigate the in situ formation of amorphous Fe oxides as a stabilization technology in As-contaminated soil. After addition of ferric nitrate and the neutralizing agent, most of extractable fractions of As in soil (i.e., SO₄^2- and PO₄^3--extractable As) was converted into As bound to amorphous Fe oxides. In addition, results of solubility bioavailability research consortium (SBRC) test indicated that a significant amount of As in untreated soil changed to a non-bioaccessible form after stabilization. The reason was attributed to the newly formed amorphous Fe oxides in the stabilized soil, which was confirmed by linear combination of fitting (LCF) using X-ray absorption spectroscopy (XAS) analysis. Interestingly, after five months of aging of the stabilized soil, ferrihydrite and schwertmannite newly formed in the soil were transformed to crystalline Fe oxides such as goethite, and further decrease in SBRC extractable fraction of As was observed. The results suggest that co-precipitated As with amorphous Fe oxides can be further immobilized with time, due to the crystallization of amorphous Fe oxides.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.4 no.2
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• pp.198-207
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• 1994

In order to evaluate the effectiveness of environmental intervention of work place, metal mercury concentration in air and in urine of the total 43 workers for 3years from December 1991 to October 1993 in a fluorescent lamp manufacturing industry exposed to mercury, was measured before and after implementation of controls such as establishing exhaust ventilation at the department of exhaustion, coating the floor of work place with epostane, cleaning of the floor, improved housekeeping, and etc. The results were as follows. 1. Before the intervention(December 1991) 39.0% exceeded metal mercury Threshold Limit Value(TLV, $0.05mg/m^3$). After the intervention(October 1993) 10.0% exceeded TLV and geometric mean of mercury in air was $0.1mg/m^3$, and showed effectiveness rate of intervention to be 74.4% 2. After the intervention, geometric means of mercury concentrations in air were 0.013, $0.019mg/m^3$ and showed effectiveness rate of intervention to be 76.6%, 65.5% in A factory(right tube lamp)and at exhaustion department, respectively, A follow up survey fround statistically significant reductions in mercury concetration in air three years later. 3. Mercury concentration in urine of 11 workers(29.7%) exceeded warning level of $100{\mu}l/l$ before the intervention. After the intervention, of 3workers(8.8%) exceeded warning level and geometric mean of mercury concentration($26.5{\mu}l/l$) in urine was 2.4 times than that of before the intervention. Geometric means of mercury concentrations in urine of workers at exhaustion department, at sealing and aging department were 44.0, $77.7{\mu}l/l$, respectively and they decreased 2.3, 3.2 times than that of before the intervention.

• Journal of Korean Society of Rural Planning
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• v.19 no.4
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• pp.237-248
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• 2013

The purpose of this study is to investigate the effect of city dwellers' migration to the rural areas on the increase of their life satisfaction and its influencing variables. Using a quota sampling, 500 city dwellers across the country and 180 migrators to the Goesan Gun in the Chungcheongbuk-do were selected. The results showed that (a) most city dwellers want to move to the rural areas for their relaxation and rest for their retirement, but migrants' main goal is to realize their internally oriented values, (b) life satisfaction is more evident for migrants compared to city dwellers, and it is influenced by self-assessed income, self-perceived health and internally oriented value, and (c) migrators contribute to their own successful aging by using strategies of selection, optimization and compensation compared to city dwellers. The contribution of this paper is to identify and confirm that (a) migration to the rural areas is an effective way to increase individual's life satisfaction although goals of dwellers and migrators are different, (b) the specific influencing variable and their weights in increase of life satisfaction are unique in Korea, and (c) income level is a not sufficient condition but necessary condition. Several managerial implications and policy directions were suggested to help both migrators and potential migrators to settle successfully in the rural areas.

• Environmental Engineering Research
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• v.25 no.3
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• pp.345-355
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• 2020

This study has been carried out to evaluate the leaching behavior of Tunisian phosphogypsum (PG) tailings in Skhira city (southern Tunisia). Two PG samples, including old and freshly deposited samples, were characterized in terms of physical, geotechnical, mechanical, chemical and mineralogical properties. Special attention was paid to their leaching behavior when subjected to standard leaching tests. Our results indicated that both samples are mainly composed of more than 31.85% CaO and 31.4% SO3, indicating the predominance of gypsum. This was further confirmed by XRD patterns that revealed the presence of characteristic reflections of gypsum, brushite, quartz and Maladrite. Compressive strength after 90 d exceeded 769 kPa, but still lower than that of natural sand (1,800 kPa). Leaching test was proposed as an appropriate method to determine the released contaminants from PG. The obtained results showed that Fluorine and Phosphorus are the most released elements from PG with 40 and 30%, respectively. The released Se, Cd, and Zn were the only trace elements that exceeded the threshold limits. It seemed that leached element concentrations were independent aging or particle size of the PG. Based on the assessment of leaching behavior, an integrated management approach of the PG deposits was proposed.

• Korean Journal of Medicinal Crop Science
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• v.20 no.6
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• pp.415-420
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• 2012

In order to evaluate the effect of seed weight on different aspect of safflower (Carthamus tinctorius L.) seed germination and growth characteristics. Quantity of sinapine leaked from seed was greater as the viability of seeds was dropped by the time elapsed of seed aging model and long storage condition in safflower (Carthamus tinctorius L.). The cultivar of safflower was Jin-Sun and the seeds that are separated to three different weights of small, middle, and large were used in this experiment. Large seeds revealed the highest germination percent, coleoptiles fresh weight, coleoptiles dry weight, radicle fresh weight and 1000 seed weights than other seed weight. Seed weight had little effect on yield while seed number exerted a positive influence. Interestingly, yield per plant and its major components, number of capsules and capsule weights, revealed a negligible relationship with oil content.