• Journal of the Korea Organic Resources Recycling Association
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• v.9 no.2
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• pp.66-70
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• 2001

In this study farm soil was tested under artificial acid rain(pH = 5.34), which is average pH of Pusan metropolitan area. and to find out the soil's acid neuralization capacity, soil acidity, CEC(cation exchange capacity)and akaline meatals, such as K, Ca and Na were tested. Because oyster shells(OS) had portion of alkaline metals, OS could play a role in acid soil amendment. And soil addition of sewage treatment sludge(STS) could be a alternative for disposal method. The purpose of this study is to evlauate acid soil amendment using STS and OS. In case of soil and STS, mixing ratio was10:0, 9:1, 8:2, 7:3. And STS mixed OS was also added in acid soil as same ratio as STS. Throught the experiment, soil acidity was stationary state with slight decrease, and CEC was also stationary state but with slight increase. Allkaline metals showed differences in concentration, but all of them were tend to decrease. In conclusion, STS mixed OS could play a part in amendment of acid soil.

• Analytical Science and Technology
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• v.18 no.3
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• pp.232-240
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• 2005

The total PCBs level in the transformer insulation oil samples using GC/ECD and HRGC/HRMS were ranged from 0.087 to $223.6{\mu}g/g$ and ranged from N.D. to $154.04{\mu}g/g$, respectively. The calculated TEQ values were ranged from 0.00067 to 6.8 ng WHO-TEQ/g. Among the samples, 6 samples showed higher than 2 ppm concentration (specific waste criterion of Korea). A variety in the concentration of total PCBs were observed between ECD and HRMS analysis. This is maybe due to quantification mehtod. The Aroclor 1248 wasn't present in the samples. The distribution pattern of Co-PCB congeners showed that the ratio of monoortho substituted congeners were higher than non-ortho substituted congeners. Among that, PCB-167 congener was predominant. In addition, the distribution of Co-PCBs congeners was different with that of flue gas and ambient air samples as well as commercial PCB formulations (Aroclor, Kanechlor).

• Journal of Korean Society of Forest Science
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• v.109 no.3
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• pp.313-324
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• 2020

This study investigated the environmental location effects that Larix kaempferi and mixed forests had on the early growth of wild-simulated ginseng (Panax ginseng C. A. Meyer) seedlings. Experimental plots were created in Larix kaempferi and mixed forests, and confirmed the location environments and growth characteristics of wild-simulated ginseng seedling. Our results showed that the soil properties, such as soil organic matter, total nitrogen, and cation exchangeable capacity were significantly higher in the mixed forest soil compared to the Larix kaempferi forest soil. Likewise, the growth characteristics of wild-simulated ginseng seedlings were significantly higher in mixed forestsd compare to the Larix kaempferi forest. Correlation analysis between tree species ratio, soil properties, and growth characteristics in the experimental plots determined that the soil properties and growth characteristics had significant positive correlation with the broad-leaved forest percentage. Growth characteristics of the wild-simulated ginseng seedlings were shown to have a significant positive correlation with organic matter, total nitrogen, and cation exchange capacities. This study has clearly demonstrated that the tree species ratio, and soil properties in Larix kaempferi and mixed forests were significantly correlated with the early growth of wild simulated ginseng seedlings. These results could help to improve the selection of suitable cultivation sites for wild-simulated ginseng.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.1
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• pp.98-107
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• 2007

Most of plastic film house plots in Korea have salinity problems caused by salt accumulations associated with continuous cropping including the heavy applications of chemical fertilizers, and high evapotranspiration. The objective of this study was to investigate soil properties and watermelon (Citrullus lanatus Thunb.) productivity in plastic film houses as influenced by the short-term crop rotation in the continuous watermelon-cultivated soils. The short-term rotational crops selected were corn, Chinese cabbage, radish, young radish, lettuce, spinach, and onion. Soil pH increased in most plots where a short-term crop was added to the crop rotation, except where radish was added. The content of soil organic matter significantly decreased in the lettuce-cultivated plot. The available phosphorus content in the soils increased with the cultivations of spinach and onion. Exchangeable Ca and Mg tended to increase in most of plots where a short-term rotational crop was grown, whereas the exchangeable K was clearly reduced by more than 50% in the same plots. Cultivation of rotational crops during the post-harvest season significantly decreased the electrical conductivity (EC) and the concentrations of soluble anions, such as chloride ($Cl^-$), nitrate ($NO_3{^-}$), and sulfate ($SO{_4}^{2-}$) in the soils. In particular, the EC decrease was related with the decrease in soil $K^+$ to $Ca^{2+}$ and $Mg^{2+}$ ratio. In all plots cultivated with the shot-term rotational crops, the ratios of bacteria to fungi (B/F) increased. However, the improvement in soil properties after adding a rotational crop did not result in a clear improvement in watermelon quantity or quality as measured by fruit weight and sugar content. Therefore, the addition of short-term rotational crops to a continuous watermelon cropping system would be beneficial to improve target soil properties in plastic film house plots studied.

• Korean Journal of Animal Reproduction
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• v.26 no.3
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• pp.245-252
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• 2002

This study was to evaluate the in vitro survival of bovine enucleated MII (eMII) oocytes according to minimum volume cooling (MVC) freezing method and activation timing, and their in vitro development after somatic cell nuclear transfer (SONT). in vitro matured bovine oocytes for 20 h were stained with 5 $\mu\textrm{g}$/$m\ell$ Hoechst, and their 1st polar body and MII plate were removed by enucleation micropipette under UV filter. Also, eMII oocytes were subjected to activation after (group II) and before (group III) vitrification in 5 ${\mu}{\textrm}{m}$ ionomycin added CRlaa medium for 5 min. For vitrification, eMll oocytes were pretreated with EG10 for 5 min, exposed to EG30 for 30 sec and then directly plunged into L$N_2$. Thawing was taken by 4-step procedures at 37$^{\circ}C$. Survived eMII oocytes were subjected to SONT with cultured adult bovine ear cells. Reconstructed oocytes were cultured in 10 $\mu\textrm{g}$/$m\ell$ of cycloheximide and 2.5 $\mu\textrm{g}$/$m\ell$ of cytochalasin D added CRlaa medium for 1 h, and then in 10 $\mu\textrm{g}$/$m\ell$ of cycloheximide added CRlaa medium for 4 h. Subsequently, the reconstructed oocytes were incubated for 2 days and cleaved embryos were further cultured on cumulus-cell monolayer drop in CRlaa medium for 6 days. Survival rates of bovine vitrified-thawed eMII oocytes in group II (activation after vitrification and thawing) and III (activation before vitrification) were 81.0% and 84.9%, respectively. Fusion rates of cytoplasts and oocytes in group II and III were 69.0% and 70.0%, respectively, and their results were not different with non-frozen NT group (control, 75.2%). Although their cleaved rates (53.4% and 58.4%) were not different, cytoplasmic fragment rate in group II (32.8%) was significantly higher than that in group III (15.6%)(P<0.05). Also, subsequent development rate into >morula in group II (8.6%) was low than that in group III(15.6%). However, in vitro development rate in group III was not different with that in control (24.8%). This result suggested that MVC method was appropriate freezing method for the bovine eMII oocytes and vitrified eMII oocytes after pre-activation could support in vitro embryonic development after SONT as equally well as fresh oocytes.

• Journal of Korean Society of Forest Science
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• v.98 no.4
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• pp.444-450
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• 2009

In this study, the physicochemical properties of the soils in the forest stands in the ecological restoration project in the Young-il Erosion Control District were investigated according to the type of plant growing therein. The soil texture was mostly sandy loam (SL), and the sand content was 59.7% on average while the average soil pH was 5.0, which was lower than the average pH of Korea's forest soil (5.5). Moreover, the average carbon, total nitrogen, and available phosphorus ($P_2O_5$) contents were 1.6%, 0.11%, and 3.7 ppm respectively. The C/N ratio was 15.1, and the average cation exchange capacity (CEC) was 13.2 cmol/kg. The physicochemical properties of the soils in the different forest stands were compared. Among all the stands, the Larix leptolepis stand had the highest pH 6.3 and the most stable C/N ratio (11.7). The Alnus firma-Styrax stand had the lowest pH 4.6 while the Pinus rigida stand had the lowest total nitrogen content. The Alnus firma-Styrax stand had the highest CEC (17.4 cmol/kg). The results showed that the Young-il Erosion Control Districtwas devastated and deprived of soil nutrients over a long period. Therefore, sustainable forest management, suchas tending and regeneration, are recommended for the Young-il Erosion Control District.

• Journal of Applied Biological Chemistry
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• v.53 no.2
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• pp.99-104
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• 2010

The influences on antioxidant activities of the substituents ($R_1-R_4$) on benzo ring in 4-Methyl-2H-benzopyran-2-one analogues (1-23) were discussed quantitatively using three dimensional quantitative structure-activity relationships (3D-QSARs: Comparative molecular field analyses (CoMFA) and Comparative molecular similarity indice analyses (CoMSIA)) methods. The statistical qualities of CoMSIA models were better than those of CoMFA models and the CoMSIA 2 model was optimized model ($q^2$=0.700 & $r^2$=0.979). Also, the contribution ratios (%) of the optimized CoMSIA 2 model were H-bond donor field 43.5%, electrostatic field 41.8% and steric field 14.7% so that the antioxidant activity exhibited a strong correlation with H-bond donor and electrostatic factor of molecules. From the analytical results of the CoMSIA contour maps, if the positive charge favor group and H-bond donor disfavor group were placed in the $R_1-R_4$ positions on the benzo ring, it was predicted that the groups would raised the antioxidant activity.

• Korean Journal of Weed Science
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• v.13 no.2
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• pp.89-95
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• 1993

The Inhibiting activity of newly synthesized phenol (E-series) and triazine (T-series) derivatives was evaluated by using thylakoid membranes extracted from cyanobacteria (Anacystis nidulans $R_2$). There were no significant differences between phenol derivatives and dinoseb to the thylakoid membrane extracted from wild type in the Hill reaction. However, a phenol derivative, E-24 which has no -Cl at phenyl ring, did not show any activity. The longer the length of R substituents was in phenol derivatives, the lower inhibiting activity was in the Hill reaction. Triazine derivatives, T-27, T-28, T-40, T-41, T-47 and T-48 were also compared with diuron and atrazine. Among triazine compounds, T-27 and T-28 showed 10 and 30 times activity as high as atrazine to wild type, respectively. Other triazine derivatives, T-40, T-41, T-47 and T-48 showed low inhibiting activity to wild and mutant type. A structural difference of T-27 and T-28 from T-40, T-41, T-47 and T-48 was the presented of -C-NH-. Both T-27 and T-28 were very closely associated with serine, an amino acid located at the 264th position of D1 protein because of the resistant ratio(R/S) to mutant G-264 were higher than that of atrazine.

• Korean Journal of Soil Science and Fertilizer
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• v.30 no.3
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• pp.280-287
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• 1997

This study was carried out to investigate agricultural status and soil fertility of Bonghwang-cheon watershed area which is located at Chodong-myeon, Milyang-si. The acreage of arable land was about 1,209ha, and the population was 3,706 people. Out of total arable land, paddy was 64.4%, upland 19.6% and orchard 16.0%. Chicken was the largest in the number of livestock and poultry, but pig seems to contribute most severly to water pollution. The geology in the lower stream was alluvium but andesite and derivated materials from it were occupied most upland areas. Tuff was scattered in the small area near by the alluvium of Nakdong river, and diorite and granodiorite were located at the low hill and mountains respectivately. The principal paddy soils in the area were Geumgog, Jisan and Imgog series etc of fine loamy on sloped valleys and fans. The Pyeongtaeg series, fine silty family of imperfectly drained on plain was irrigated by Chodong reservoir. The clayey Honam series on alluvium was distributed along the low hill while Gyuam series, coarse silty alluvial soil way close to Nakdong river. In chemical properties of soils, the vinyl house soils were higher in EC, and orchard soils in OM, $P_2O_5$, exchangeable canons than other soils.

• Journal of the Korea institute for structural maintenance and inspection
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• v.21 no.6
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• pp.74-82
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• 2017

This research presents the results of the strength and drying shrinkage properties to study the effect of ground granulated blast furnace slag(GGBFS), fly ash(FA) and calcium sulfoaluminate(CSA) for activated ternary blended slag cement. The activated ternary blended cement(ATBC) mortar were prepared having a constant water-cementitious materials ratios of 0.4. The GGBFS contents ratios of 100%, 80%, 70% and 60%, FA replacement ratios of 10%, 20%, 30% and 40%, CSA ratios of 0%, 10%, 20% and 30% were designed. The superplasticizer of polycarboxylate type were used. The activator was used of 10% sodium hydroxide(NaOH) + 10% sodium silicate($Na_2SiO_3$) by weight of binder. Test were conducted for mini slump, setting time, V-funnel, water absorption, compressive strength and drying shrinkage. According to the experimental results, the contents of superplasticizer, V-funnel and compressive strength increases with an increase in CSA contents for all mixtures. Moreover, the setting time, water absorption ratios and drying shrinkage ratio decrease with and increase in CSA. One of the major reason for the increase of strength and decrease of drying shrinkage is the accelerated reactivity of GGBFS with alkali activator and CSA. The CSA contents is the main parameter to explain the strength development and decreased drying shrinkage in the ATBC.