• Economic and Environmental Geology
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• v.34 no.4
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• pp.417-422
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• 2001

Sutfactants may be used in remediation of subsoil and aquifer contaminated with hydrophobic compounds. The objectives of this study were to select potentially suitable sUlfactants that solubilize toluene present as a contaminant and to determine the effectiveness of toluene removal from Ottawa sand by the selected surfactants. Material used as the model soil was Ottawa sand and the organic used as model contaminant was toluene. Used experimental methods were separatory funnel experiment and shaker table agitation/centrifugation experiments. Based on the experimental results, the following conclusions were drawn; t) In the surfactant selection, six different surfactants were chosen based on surfactant types, toxicity, and water solubility. These six were focused into two on the basis of HLB and surface tension study, separatory funnel experiment, shaker table and centrifugation experiments. The two most suitable surfactants were Sandopan JA36 (an anionic surfactant), and Pluronic L44 (a non-ionic surfactant). 2) In the shaker table agitation and centrifugation experiments, the highest recovery of the toluene was 96% which was obtained with one surfactant wash plus two water rinses using an anionic surfactant (Sandopan JA36).

• Journal of the Korea Organic Resources Recycling Association
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• v.5 no.2
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• pp.29-37
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• 1997

Because food waste have high moisture content, landfill or incineration is not most suitable. The reuse of food waste by composting contribute to solve resourse, environmental, aglicultural problems. The purpose of this research is to optimise operating conditions and to develop new microorganisms for recycling of food waste by ultilizing small-scale composting equipment. The reduction rate of food waste was 75~85% by weight, and it was coincided with moisture reduction. When initial moisture was 25%, 45% and 60%, C/N ratio on based net weight was 9.8, 10.7 and 11. 8, respectively. And it was suitable for composting. But, The developed microorganism, PNU2, was better than existing commercial seed in the activity based on $CO_2$ concentration.

• Resources Recycling
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• v.24 no.5
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• pp.56-62
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• 2015

Solvent extraction experiments for the separation and recovery of Re from hydrochloric acid leaching solution of spent super alloy by Alamine 304-1 were carried out. The effects of some variables, such as the nature and concentration of the extractants, HCl concentration, and the presence of impurities were investigated. The synthetic solutions of Re were prepared by dissolving ammonium perrhenate (APR), Alamine304-1, Cyanex272 and $D_2EHPA$ were used solvent extractants distilled in kerosene. The extraction percentage of Re by Alamine304-1 was higher than the other extractants as Cyanex272 and $D_2EHPA$ and the percentage is about 99%. Only 99% of Re was extracted in the presence of Al, Co and V in HCl solution.

• Resources Recycling
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• v.18 no.5
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• pp.44-51
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• 2009

Fundamental study has been made on the recovery of copper from the electronic scrap by hydrometallurgical process. Nitric acid was used as a leaching agent to dissolve the metals such as Cu, Sn, Pb, Fe etc. from the crushed electronic scraps. TBP was employed to extract nitric acid from the strong nitric acid leaching solutions and to reclaim nitric acid. From the experimental results, Cu was effectively leached by 3.0-4.0 M nitric acid. And 95% of nitric acid in the leaching solution was extracted by 60% TBP, and 98% of nitric acid was stripped from the loaded organic phase by distilled water and it was possible to reuse as a leaching agent.

• Resources Recycling
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• v.23 no.2
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• pp.37-45
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• 2014

Solvent extraction experiments have been performed to separate Nd and Pr from chloride leaching solution of monazite sand using single Cyanex272 and mixed extractants as PC88A+Cyanex272 and PC88A+TBP. For this purpose, the effect of the concentration of extractants on the extraction and separation of the two metals were studied by varying the pH of aqueous solution. In the experimental ranges conducted in this study, the distribution coefficients of Nd were higher than those of Pr. In Cyanex272 system, our results indicated that concentration of extractant and initial pH did not affect distribution coefficients, but separation factor was increased with increasing initial pH. In binary extractant system, distribution coefficients were lower than those of single PC88A system, whereas separation factor was similar in both mixed and single extractant system.

• Korean Journal of Plant Resources
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• v.24 no.5
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• pp.564-583
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• 2011

The flora of Gitdae-bong area were investigated from March, 2009 to September, 2010. The vascular plants were summarized as 435 taxa; 90 families, 272 genera, 380 species, 3 subspecies, 45 varieties, and 7 forma. Among the investigated 435 taxa, twelve Korean endemic, eight rare plants and 68 specially designated plants by Ministry of Environment were also included. The naturalized plants were 15 taxa and percent of naturalized plant species was 3.4%. Usefulness of plants of 435 taxa listed consists of 203 taxa (46.7%) of edible plants, 141 taxa (32.4%) of medicinal plants, 64 taxa (14.7%) of pasture plants, 44 taxa (10.1%) of ornamental plants, 18 taxa (4.1%) of timber plants, 15 taxa (3.4%) of fiber plants and 4 taxa (0.9%) of industrial plants.

• Korean Journal of Plant Resources
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• v.29 no.2
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• pp.171-188
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• 2016

This study was carried out to investigate the flora of Mt. Baegam (1,099 m) from March, 2014 to July, 2015. The vascular plants were summarized as 506 taxa, including 90 families, 293 genera, 435 species, 5 subspecies, 58 varieties and 8 forms. Among the investigated 506 taxa, 14 Korean endemic, 16 rare plants and 80 specially designated plants (V degree: 3 taxa, IV degree: 7 taxa, III degree: 22 taxa, II degree: 21 taxa, I degree: 27 taxa) by the Ministry of Environment were also included. The naturalized plants were 36 taxa including 3 ecosystem disturbance wild plant. The urbanization index and percent of naturalized plants species were estimated as 11.2% and 7.1%, respectively. Useful plants of 506 taxa listed consists of 207 taxa (40.9%) of edible plants, 200 taxa (39.5%) of pasture plants, 146 taxa (28.9%) of medicinal plants, 58 taxa (11.5%) of ornamental plants and 15 taxa (3.0%) of timber plants, respectively.

• Korean Journal of Plant Resources
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• v.31 no.1
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• pp.16-23
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• 2018

Paeonia japonica is a perennial flowering plant used in traditional medicine therapy. The purpose of this study was to investigate the effect of water extract and solvent fractions obtained from P. japonica on anti-oxidative, anti-thrombin, anti-invasive and pro-apoptotic activities in YD-10B cells, human oral squamous carcinoma cell line. Water fraction revealed the highest extraction yield at 11.44% (w/w). Anti-oxidative activity was the highest in ethyl acetate fraction (85.13%). In the thrombin inhibitory activity test, ethyl fraction was the highest, with a value of 87.54%. Release and activation of MMP-2/pro-MMP-2 ratio in thrombin-treated YD-10B cells were significantly inhibited in the ethyl acetate fraction. At a concentration of $120{\mu}g/m{\ell}$ water extract and solvent fractions of P. japonica inhibited cell proliferation in YD-10B cells except water fraction. Pro-apoptotic effect on human oral squamous carcinoma cell using the Bax/Bcl-2 ratio analysis was higher in water extract than other fractions. These findings suggest that the ethyl acetate fraction of P. japonica potentiates a promising antioxidant, anti-thrombin and anti-invasive agents.

• Journal of the Korean Recycled Construction Resources Institute
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• v.1 no.3
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• pp.219-224
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• 2013

In this study, the inorganic insulating material was fabricated with quartzite, ordinary portland cement(OPC), lime and anhydrous gypsum. After characteristic analysis of slurry, the optimum mixing ratio was derived with different $CaO/SiO_2$ mole ratio. Based on derived mixing ratio, the inorganic insulating material was fabricated at different water content and hydrothermal synthesis conditions. Specific gravity was $0.26g/cm^3$, compressive strength was 0.4 MPa, and thermal conductivity was 0.064 W/mK. This properties were enhanced performance of conventional ALC (Autoclaved Lightweight Concrete). And it can replace organic insulation with harmless inorganic insulation through continues research and development.

• Korean Journal of Plant Resources
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• v.9 no.3
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• pp.305-310
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• 1996

Five edible mountain vegetables(Saussurea sp. Aster tataricus, A. scaber. Synurus deltoides, Ligularia fischeri) were investigated on the basis of amplified DNA polymorphisms resulted from PCR (polymerase chain reaction) analysis. The sampled plants consisted of 38 individuals in 5 taxa. Only 10 primers out of 62 primers (60 random [10-mer] primers, two 15-mer [M13 core sequence, and (GGAT) sequence]) tested gave rise to polymorphisms in all of the tested plants, producing 176 DAN fragments amplified. Intraspecific polymorphisms found in each taxa showed intraspecies constancy (31.1-61.1%) in the banding patterns of individual plants: Saussurea sp. 31.1%, 15 bands, Aster tataricus, 40.9%, 18 bands, A. scaber. 38.5%, 15 bands. Synurus deltoides, 34.7%, 17 bands, and Ligularia fischeri, 61.1%, 22 brands, respectively. All five species were well classified from each other at the 0.93 level of similarity index value. Intraspecific and interspecific variations were appeared at the levels ranging from 0.62 to 0.99. Based on these results, our PCR analyses support the previous data derived from external morphology of the 5 edible mountain vegetables, but very low levels o intraspecific variations were detected in all of these taxa.