• Korean Journal of Environment and Ecology
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• v.26 no.5
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• pp.707-718
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• 2012

This study was conducted to monitor 4 years of changes in the vegetation structure starting from 2007 when restoration began and propose vegetation management ideas for the riparian ecological restoration areas in the purchased land around Nakdonggang(River). The study was conducted in each of 15 locations ($208,342m^2$) in the riparian ecological restoration areas in November 2007, September 2008, October 2009 and September 2010. The analysis results of the changes in planting species and population showed that, in the case of trees, Acer pseudo-sieboldianum, Quercus acutissima, Acer ginnala, Quercus aliena, Quercus variabilis indicated relatively little changes in their numbers and Quercus dentata, Cornus walteri, Morus alba, Styrax obassia, Sorbus alnifolia var. macrophylla indicated a 100% withering rate. Most shrubs withered due to the oppressive pressure of herbs and climbing plants. The planting density decreased over 4 years on average 28 plants/$100m^2$ to 20 plants/$100m^2$ to 16 plants/$100m^2$. Shortly after the restoration, The the amount of growth was reduced by restoration stress. however as time goes on after the restoration tended to stabilize. The changes in the basal area showed a decrease from $507.1cm^2/100m^2$ in 2007 right after restoration to $301.8cm^2/100m^2$ in 2008 and afterwards showed an increasing trend by going to $324.9cm^2/100m^2$ in 2009 and $372.7cm^2/100m^2$ in 2010. To improve the planting structure of the riparian ecological restoration area, the selection of tree species that have been considered for soil moisture and the differentiation of suitable planting structures that have been considered for local conditions were needed.

• Korean Journal of Environment and Ecology
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• v.30 no.6
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• pp.939-961
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• 2016

For effective conservation of endangered wild plants, it is necessary to understand their interactions with environmental factors in each habitat together with life traits of target species. First, the characteristics of their distribution were investigated followed by their monitoring for 4 years focusing on the habitats in the lagoon. Also, their life traits were compared including production of hibernacles, fruits, and seeds by the soil fertilization and light intensities. Next, the information on the species was secured by germination experiment using the generated seeds from the cultivation experiment. The habitat of Glaux maritima var. obtusifolia Fernald in Korea was located in the rear edge of the worldwide distribution and its four habitats were isolated and distributed far away each other. Two of them were located in small salt-marsh and fine sand estuaries formed in the rocky area of the seashore, and the other two were inhabited with the sandy soil in the lagoon which was connected by river-mouth to the sea. Glaux maritima var. obtusifolia Fernald tends to be distributed in the sites where the establishment and growth of the competitor were inhibited by salinity, periodic flooding, and lower layer of the soil to extend a roots. It maintained its population by recruitments of hibernacles and seedling. The production of hibernacle was assumed to be affected by the particle consist of the sand together with organic matters in the soil. Seedling recruitment was observed only in the salt-marsh area located in the rear sites of sand ridge where was the shore of the lagoon. Glaux maritima var. obtusifolia Fernald was observed to have different threatening factors by each population. Its population in Pohang seemed the sedimentation of fine sand which affected the recruitment of hibernacles had been eroded due to the construction of the coastal road. The population in Ulsan appeared rapid expansion of competitor and reduction of its distribution area due to the interruption of eluted water supplied to the habitat. On the other hand, the habitat in the lagoon maintained the population relatively stable. Especially, the population in Songji-ho was determined to be the most stable one. To sustain the population of Glaux maritima var. obtusifolia Fernald distributed in the lagoon, it is suggested that the wide ranged scale of conservational activities is necessary to maintain the mechanisms including the entrance of seawater which belongs to the lagoon, and periodic flooding.

• Journal of the Korean Institute of Landscape Architecture
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• v.37 no.4
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• pp.32-41
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• 2009

Places such as famous urban sights and foreign settlements have recently been created in Korea, which reflects the increase in social and cultural exchanges and the number of place-making and landscape-planning projects. Understanding place identity is required in environmental design and planning. This paper examined the components of the identity of place through comparison of perceptions of "placeness" between residents and visitors of Seo-Rae Village, Seoul, Korea. More than 40% of French nationals in Korea reside in the village, which many Koreans visit as an urban sightseeing place. Twenty-five French inhabitants and forty-one Korean visitors were surveyed. Insideness of Seo-Rae Village was formed by limited activities and needs of the residents, primarily children's education and food purchases. Residents mentioned that the physical environment, especially buildings, lacked theauthenticity of French style. The symbolic meaning of the French village influenced the visitors' activities. The authenticity of French style, however, did not affect the perception of visitors and outsideness of the place. Visitors' activities and cognitive meanings of the place were formed mainly by the commercial environment established by Korean investments. Commercialization of the place and related activities played an important role in establishing insideness of the place. The village shows the phenomenon of the reversal of insideness and outsideness. The "placeness" of Seo-Rae village has been shaped by visitors' tastes rather than the true experience of insideness. Mass identity formed by mass media using French characteristics influenced this phenomenon. Insideness formed by inhabitants appeared to be a pseudo-place, which was created by the French tastes of visitors and lacked French authenticity. Seo-Rae Villagerepresents a superficial cloak.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.1
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• pp.1-10
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• 2005

The purpose of this study was to evaluate the potential of a gamma irradiation to decompose 2,4,6-trinitrotoluene(TNT) in an aqueous solution. The decomposition reaction of TNT by gamma irradiation was a pseudo first-order kinetic over the applied initial concentrations($25{\sim}100mg/L$). The dose constant was strongly dependent on the initial TNT concentration. The removal of TNT was more efficient at pH below 3 and at pH above 11 than at neutral pH(pH 5-9). The required irradiation dose to remove over 99% of TNT was 40, 80 and 10 kGy, individually at pH 2, 7 and 13. The dose constant was increased by 1.6 fold and over 15.6 fold at pH 2 and 13, respectively, when compared with that at pH 7 When irradiation dose of 200 kGy was applied, the removal efficiencies of TOC were 91, 46 and 53% at pH 2, 7 and 13, respectively. Ammonia and nitrate were detected as the main nitrogen byproducts of TNT and glyoxalic acid and oxalic acid were detected as organic byproducts. The results showed that a gamma irradiation was an attractive method for the decomposition of TNT in an aqueous solution. However, regarding the application of high energy radiation for the TNT decomposition and mineralization, an application of an acidic pH below 3 to the solution before irradiation should be considered.

• Journal of Korean Society of Forest Science
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• v.105 no.3
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• pp.275-283
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• 2016

The objective of this study was to examine carbon dynamics with biomass, soil $CO_2$ efflux, litter and root decomposition after tree density control in young Pinus densiflora stands. The stands were established with 50% thinning, clear-cut, and control stands with three pseudo-replicated plots and a bare soil plot in 8-year-old Pinus densiflora nursery field. Monthly measurements were conducted from March 2012 to February 2014 and aboveground biomass and coarse-roots were estimated by derived allometric equations. Average diameter growth at root collar in control and thinned was 0.89 cm and 1.48 cm per year, respectively, and the diameter growth of control stand was significantly higher than that of thinned stands (p<0.05). Total biomass was estimated to 5.17, $4.85kg\;C\;m^{-2}$ per year in control and thinned, respectively. Annual soil $CO_2$ efflux in control, thinned, clear cut, and bare soil was 3.71, 3.90, 4.17, $4.56kg\;CO_2\;m^{-2}\;yr^{-1}$, respectively and removing trees significantly increased soil $CO_2$ efflux (p<0.05). Net Ecosystem Production (NEP) was 1.57, 1.36, -0.67, $-1.25kg\;C\;m^{-2}\;yr^{-1}$ in control, thinned, clear cut and bare soil in the young Pinus densiflora stands. NEP was significantly decreased by removing trees. Thinning increased diameter at root collar and carbon of individual tree and recovered 86% of carbon removed by thinning after one-year. In addition, soil $CO_2$ efflux increased and NEP increased by thinning. Results of this study, tree density control such as thinning increased the carbon storage and growth of the young Pinus densiflora stands.

• Clean Technology
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• v.17 no.1
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• pp.48-55
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• 2011

The application of fibrous activated carbon (FAC)-titanium dioxide ($TiO_2$) hybrid system has not been reported yet for the control of malodorous dimethyl sulfide (DMS) at residential environmental levels. Accordingly, the current study was designed not only to characterize this hybrid system using x-ray diffraction method, particulate surface measurement and Fourier transform Infrared (FTIR) method, but also to evaluate its adsorptional photocatalytic activity (APA) for the DMS removal. The physical/surface characteristics of FAC-$TiO_2$ which was prepared in this study suggested that the hybrid material might have certain APA for DMS. The Brunauer-Emmett-Teller (BET) specific area, total pore volume, micropore volume and mesopore volume decreased all as the $TiO_2$ amounts coated on FAC increased, whereas the reverse was true for average pore diameter. $TiO_2$ coated onto FAC did not influence the adsorptional activity of FAC for the DMS input concentration of 0.5 ppm. The APA test of the hybrid material presented that the initial removal efficiencies of DMS were 93, 78, 71 and 57% for the flow rates of 0.5, 1.0, l.5 and 2.0 L/min, respectively, and they decreased somewhat 2 h after the experiment started and kept almost constant for the rest experimental period. Under this pseudo-equilibrium condition, the DMS removal efficiencies were 78, 58, 53 and 36% for the four flow rates, respectively. Meanwhile, there were no significant byproducts observed on the surfaces of the hybrid material. Consequently, this study suggests that, under the experimental conditions used in the present study, the hybrid material can be applied for DMS at residential environment levels without being interfered by any byproducts.

• Korean Journal of Agricultural and Forest Meteorology
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• v.5 no.3
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• pp.158-165
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• 2003

This study was conducted to reveal the role of meteorological elements on the habitat characteristics and vegetative structure for S. commixta natural populations at Ulleung Island. Potential Evapotranspiration(PET) by elevation of Ulleung Island was estimated using Thornthwaite's climatology estimating method. Also, Warm Index (WI), Coldness Index (CI) and vegetative composition by elevation were determined. The following results were obtained: The S. commixta trees wire mainly distributed from an elevation of 300 m to 900 m. The WI and CI were about 66.8∼95.0, -21.5∼-7.7, respectively. Water deficit by precipitation and Potential Evapotranspiration (PET) mainly occurred from March to October at all elevations. But wafer deficits diminished with increased elevation. The apparent species in S. commixta natural populations at Ulleung Island were: 10 tree layer species, 17 subtree layer species, and 25 species in the shrub layer. In the tree layer, S. commixta was dominant with the highest value of 46.85, then Fagus crenate 13.43, Acer mono and Tilia amurensis 12.41 and 12.03, respectively. In the subtree layer, A. mono was dominant with the highest value of 13.16, then F. crenata 12.68, Acer pseudo-sieboldianum and S. commixta 11.37 and 10.76, respectively. Dominant species and IV values in the shrub layer were Sasa borealis (22.09) and Rhododendron brachycarpum (10.51). The S. commixta natural forests were in a relatively stable rendition because of the even distribution of its various indexes: the species diversity index of Shannon, the evenness index and dominance were 0.6199∼1.1390, 0.6199∼0.8825 and 0.1852∼0.3801, respectively.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.4
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• pp.278-286
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• 2009

In this study, four natural Mn oxides ($NMO_1-NMO_4$) was characterized using x-ray diffraction, scanning electron microscopy, and their removal efficiency for 1-naphthol (1-NP) in aqueous phase, using batch reactor, was investigated. The results were compared with one another and a synthetic manganese oxide, birnessite. The NMOs have a various Mn minerals including pyrolusite (${\beta}-MnO_2$), cryptomeltane (${\alpha}-MnO_2$) as well as birnessite (${\delta}-MnO_2$) depending on their sources, which results in different removal efficiencies (removals, kinetics) and reaction types (sorption or oxidative-transformation). The comparative study showed that $NMO_1$ (electrolytic Mn oxide) have a higher removal efficiency for 1-NP via oxidative-transformation compared to birnessite. The 1-NP removals by NMOs were followed by pseudo-first order reaction, and the surface area-normalized specific rate constants ($K_{surf},\;L/m^2$ min) determined were in order of $NMO_1(3.31{\times}10^{-3})$>${\delta}-MnO_2(1.48{\times}10^{-3}){\fallingdotseq}NMO_3(1.46{\times}10^{-3})$>$NMO_2(0.83{\times}10^{-3})$>$NMO_4(0.67{\times}10^{-3})$. From the solvent extraction experiments with the Mn oxide precipitates after reaction, it was observed that the oxidative-transformation rates of 1-NP were in order of $NMO_1{\fallingdotseq}{\delta}-MnO_2$>$NMO_3$>$NMO_4{\gg}NMO_2$ and the analysis of HPLC chromatogram and UV-Vis. absorption ratios ($A_{2/4}$, $A_{2/6}$) on the supernatant confirmed that the reaction products were oligomers formed by oxidative-coupling reaction. Results from this study proved that natural Mn oxide (except $NMO_2$) used in this experiment can be effectively applied for the removal of naphthols in aqueous phase, and the removal efficiencies are depending on the surface characters of the Mn oxides.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.4
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• pp.237-245
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• 2014

Amur silver grass (Miscanthus sacchariflorus) and reed canary grass (Phalaris arundinacea) were selected for RDX removal experiments in hydroponic culture conditions based on vegetation survey at three shooting ranges in northern Kyunggi province. Seedling of two plants were grown in 1/4 strength Hoagland solution in quadruplicates containing 10, 20, 30, 40 mg/L RDX for 15 days along with control and blank treatments. During the 15 days of incubation, pH and RDX concentration in medium were routinely analyzed and RDX contents in the shoot and the root were determined after solvent extraction at the end of the experiments. Both plant species showed no symptoms of RDX phyto-toxicity. The pseudo first order RDX-removal constants for amur silver grass and reed canary grass were in the range of $0.0143{\sim}0.0484day^{-1}$ and $0.0971{\sim}0.1853^{-1}$, respectively. Plant biomass normalized RDX removal rates, which decreased with the increase of initial RDX concentration, were in the range of $0.27{\sim}1.01mL{\cdot}g^{-1}day^{-1}$ and $0.87{\sim}1.66mL{\cdot}g^{-1}day^{-1}$ for amur silver grass and reed canary grass, respectively. After 15 days of treatment, RDX removal from the medium decreased from 49.0% to 23.7% with increase in the initial RDX concentration in amur silver grass and 7.3% of the initial RDX remained in the plant. In reed canary grass planted medium, less than 16.8% and 5% of the initial RDX remained in the medium and in the plant, respectively. Large quantities of unidentified polar compound, which was not detected in amur silver grass, accumulated in the root and shoot of reed silver grass.

• Journal of the Korean Wood Science and Technology
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• v.14 no.4
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• pp.14-20
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• 1986

These experiments were carried out to determine the ultraviolet absorption spectra of AcBr lignins(acetyl bromide lignin) from 10 hardwood species grown in Mt. Jiri. 1. There were 3 peak positions, at 249nm(max. peak), at 262-266nm(shallow min. peak) and at 270-280nm(lower max. peak). The Bj$\ddot{o}$rkman lignin and lignin sulfonatic acid spectra had shoulders, but the AcBr lignin didn't. 2. Average absorbances of the AcBr lignin at peak positions were 0.457${\pm}$0.0077 at 249nm, 0.297${\pm}$0.0029 at 262-266nm and 0.309${\pm}$0.0067 at 270-280nm. 3. Average absorptivities of the AcBr lignin at peak positions were 25.005${\pm}$0.3825 at 249nm, 16.264${\pm}$0.2347 at 262-266nm and 16.863${\pm}$0.3444 at 270-280nm. 4. AcBr lignin absorptivities in each species were as follows: 16.939${\pm}$0.3735 in Acer pseudo-sieboldianum var. koreanum, 17.411${\pm}$0.2937 in Carpinus laxiflora, 16.579${\pm}$0.4348 in Comus controversa, 16.385${\pm}$0.4140 in Fraxinus rhynchophylla, 16.287${\pm}$0.4156 in Meliosma myriantha, 16.492${\pm}$0.1432 in Platycarya strobilacea, 16.343${\pm}$0.3177 in Prunus sargentii, 17.549${\pm}$0.3253 in Sophora japanica, 18.400${\pm}$0.2925 in Stewartia koreana, 16.245${\pm}$0.4339 in Styrax obassia. 5. As the spectra of AcBr lignin from hardwood showed the unpromounced peak from 270nm to 280nm, it was supposed that thes hardwood lignins were the guaiacyl-syringyl copolymers.