• Korean journal of applied entomology
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• v.32 no.3
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• pp.271-278
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• 1993

This experiment was carried out to elucidate the mfluence of honeybees pollinatIOn on yield and YIeld components of soybean at the Kyungbuk Provincial Rural Development Administration from 1990 to 1991. SIX soybean varieties were cultivated in net houses with and without bees. Italian honeybees(Apis melhfem L.) were used. The Vlsiting frequency of bees in net house wIth bees was 58% higher than that of field honeybees, and it was the highest at 10 A.M. during a day. Number of pods per plant and podding ratio of soybean were higher with bees compared with Wlthout bees, especially for the varieties Paldalkong and Dankyongkong. The number of seeds per pod was not significantly different between with bees and without bees, although the percentage of three seeded pod of varieties Danyeobkong and Muhankong and one seeded pod of varieties Hwangkeumkong and Milyangkong 'was increased. The percentage of three seeded pod of Paldalkong and Dankyeongkong, however, was decreased with bees compared with without bees. At the same time no varietal difference was found in two seeded pods between with bees and without bees. Yield of soybeans was increased 0 to 12 % with bees compared with that of without bees. Yield increase was the hIghest in Paldalkong and Dankyongkong. The ratIO of soybean hybrid plant was mcreased with-bees compared with that of without-bees, especially m Paldalkong and Dankyongkong. A negative correlation was found between the ratio of hybrid plant and the duration of flowering in soy¬beans.

• Korean journal of communication and information
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• v.27
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• pp.283-316
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• 2004

This study examines different news frames of local newspapers reporting the controversial 'Nu[lear Waste Site' issues which deeply split regions showing their intention to bid for the state affair. Three local papers were analyzed for this study, "Gwang-Ju-Il-bo" "Mae-il-sin-mun" and "Jun-buk-il-bo." Overall, the three local papers displayed widely divergent main news frames on the same issue. Firstly, "Gwang-Ju-Il-bo", and "Mae-il-sln-mun" showed the strong tendency of using 'counter frame' while "Jun-buk-il-bo" exhibited 'loral development frame'. Secondly, "Gwang-Ju-Il-bo", and "Mae-il-sin-mun" were frequently headlined 'Nuclear Waste Site', while "Jun-buk-il-bo" carried headlines 'Radioactive Waste Management Facility' overwhelmingly more often than the other two papers, indicating that headline key words are closely associated with the configuration of news frames. Thirdly, the main news frames remained consistent for "Gwang-Ju-Il-bo", and "Mae-il-sin-mun" even after the government's report about the possible connection of 'ion-beam irradiation-accelator' and 'Nuclear Waste Site.' On the other hand, "Jun-buk-il-bo" was significantly less headlined 'Nuclear Waste Site' while significantly more headlined "Radioactice Waste Management Facility." "Jun-Buk-il-bo" which is in stark contrast to the other two papers changed in its tone by increasing the 'local development frame' with decrease in the 'counter frame.' The "Jun-buk-il-bo"'s more frequent use of 'Radioactive Waste Management Facility' as a headline than "Nuclear Waste Management Equipment" is seen as its attempt to minimize negative image of Nuclear Waste and to promote favorable public opinion by highlighting aspects of economic benefits and the local development the construction would brind about. The major findings of this study further support the claim that media overage ends up a reality. The fact that Buan in Jun-buk Province made a successful bid for the construction is not a coincidence.

• Korean Chemical Engineering Research
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• v.45 no.5
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• pp.433-441
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• 2007

This work investigated the stability of a Sn-modified Pt electrode, which was used for reduction of nitrate, fabricated by an adsorption or electro-deposition of Sn on Pt. In order to find the causes for instability of the electrode, the effects of the solutions in which the electrode was used and the potential applied to the electrode on the electrochemical and metallurgical behaviors of Sn on Pt were studied. The Sn of freshly- prepared modified-Sn Pt electrode existed as Sn hydroxide form, which brought about an easy loss of the electro-activity of the electrode even staying in water, especially in acid solution. When the Sn-modified Pt electrode was used for the reduction of nitrate, the electro-activity of the electrode was affected depending on the potential applied to the electrode. When a more negative potential than the redox equilibrium potential between $Sn(OH)_2$ and Sn was applied to the electrode, the Sn hydroxide was converted to Sn that could diffused into Pt, which leaded to the loss of electro-activity of the electrode as well. The solid diffusion of Sn increased linearly with the applied potential. The Sn-electrodeposited Pt electrode which had more Sn on the electrode was more favorable to maintaining the integrity of the electrode during the reduction of nitrate than the Sn-adsorbed Pt electrode prepared in the under-potential deposition way.

• Analytical Science and Technology
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• v.5 no.3
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• pp.239-247
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• 1992

The complexations and selectivities of the 10 species of mono- and dimethylsubstituted anilinium ions with 18-crown-6 in methanol are examined at dropping mercury electrode. The stability constants of these complexes varies drastically due to the steric hindrance by the positions and numbers of methyl groups. And the analyses of the isomeric mixtures of methylanilinium, which are impossible to detect due to the overlapped peaks in normal conditions, were also accomplished by the additions of 18-crown-6 as the supporting complexing agent using the selective complexations by the steric hindrance effects. As results in case of the difference of stability, ${\Delta}log\;K$ were about 0.7~1.3, it was possible to confirm the existence of two species qualitatively. Otherwise when ${\Delta}log\;K$ were large than 1.6, the quantitative determinations of each species could be accomplished sucessfully. From these results it is deduced that the selective recongnition of the positions and numbers of methyl groups as the steric hindrance in anililniums by 18-crown-6 cause the large variation of the magnitudes of negative shift of reduction waves for guest ions in mixtures.

• Korean Journal of Environmental Agriculture
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• v.5 no.1
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• pp.11-23
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• 1986

Soils and rice plants in wastewater irrigated area of the Mangyeong River receiving waster from the Jeonju Industrial Complex and municipal sewage were sampled at two depths to assess the nature and content of Cd, Cu, Pb and Zn, particularly with respect to distance from wastewater source. For metal levels of soils in these area, no difference in the heavy metal contents between the surface and the subsurface soils was found. Total contents of Cu, Pb and Zn in soils were negatively correlated with distance from the source. A positive correlation was found between contents of total and 0.1N-HCl extractable or $1N-CH_3COONH_4$ extractable heavy metals in surface soils of these area. Total contents of heavy metals in soils were positively correlated with clay, soil organic matter and cation exchange capacity. Heavy metal contents of brown rice sampled at the Jeon-ju Industrial Complex area ranged from 0.15 to 0.91 ppm for Cd, from 1.13 to 5.68 ppm for Cu, from 0.22 to 7.16 ppm for Pb and from 11.74 to 38.66 ppm for Zn. Negative correlation was found between the contents of Cd, Cu, Pb, and Zn in the brown rice and the distance from the source. The contents of Cd, Cu and Zn in rice straw were positively correlated with those in the brown rice.

• Journal of Food Hygiene and Safety
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• v.33 no.5
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• pp.354-360
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• 2018

This study presents a method validation for extraction and quantitative analysis of trichothecene mycotoxins in nuts based on quick, easy, cheap, effective, rugged, and safe (QuEChERS) approach for extraction and enhanced matrix removal (EMR)-lipid-disperive-SPE (d-SPE) cleanup method, with detection and quantification by high-performance liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) in positive- and negative-ion modes. Linearity, precision, and accuracy were validated for LC-MS/MS methods. Results obtained with LC-MS/MS were linear, with correlation coefficient ($R^2$) of 0.998. Limits of detection and quantification for mycotoxins were $0.41-3.57{\mu}g/kg$ and $1.23-10.82{\mu}g/kg$, respectively. Intra- and inter-day precisions (RSD, %) were 0.40-8.44% and 1.93-12.46%, respectively. Results indicated to be rapidly and accurately identifying trichothecene mycotoxins and may be used as a suitable safety management method for nuts and nuts related commodities.

• Korean Chemical Engineering Research
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• v.43 no.1
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• pp.60-65
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• 2005

The electrosorption of U(VI) from waste water was carried out by using activated carbon fiber(ACF) felt electrode in a continuous electrosorption cell. In order to enhance the electrosorption capacity at lower potential, ACF felt was chemically modified in acidic, basic and neutral solution. Pore structure and functional groups of chemically modified ACF were examined, and the effect of treatment conditions was studied for the adsorption of U(VI). Specific surface area of all ACFs decreases by this treatment. The amount of acidic functional groups decreases with basic and neutral salt treatment, while the amount increases a lot with acidic treatment. The electrosorption capacity of U(VI) decreases on using the acid treated electrode due to the shielding effect of acidic functional groups. Base treated electrode enhances the capacity due to the reduction of acidic functional groups. The electrosorption amount of U(VI) on the base treated electrode at -0.3 V corresponds to that of ACF electrode at -0.9 V. Such a good adsorption capacity was not only due to the reduction of shielding effect but also the increase of $OH^-$ in the electric double layer on ACF surface by the application of negative potential.

• Korean Journal of Microbiology
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• v.36 no.2
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• pp.79-83
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• 2000

Activated sludge samples were collected from a municipal sewage treatment plant and used for enrichment of microbial consortia with aniline as the sole carbon and nitrogen source. Threc aniline-degrading bacteria were obtained lrom microbial consortia and an isolate which has excellent aniline degradability was selected for this study. The isolate was Gram-negative, and identified and designated as Delfha sp. JK-2 on the basis of various physiological and biochemical tests. 10 mM aniline was completely degraded within 24 hours after inoculation of the culture. Ammonium ion was liberated in the medium transiently during the incubation and disappeared when aniline was completely degraded. Addition of glucose as a supplementary source to aniline minimal media showed significant decrease in aniline degradat~on rate for the strain Effective degradation of aniline was achieved by the addition of 0.5% nitrate as a nitrogen source, and resulted in approximately 80% higher aniline degradation compared to the absence of nitrate. Phylogenetic analysis based on 16s [DNA sequence revealed that the strain was closely related to De@ia acidovorans, with 96% overall similarity. The 16s [DNA sequence of JK-2 was also found to be closely related to those of six other clonal types, including Acidovoru, Aquaspirillum. Xylophilus, Variovorm, and Rhodofernr.

• Korean Journal of Microbiology
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• v.39 no.3
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• pp.175-180
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• 2003

Microbial Fe(III) reduction is an important factor for biogeochemical cycle in anaerobic environments, especially sediment of freshwater such as lakes, ponds and rivers. In addition, the Fe(III) reduction serves as a model for potential mechanisms for the oxidation of organic compounds and the reduction of toxic heavy metals, such as chrome or uranium. Shewanella putrefaciens DK-1 was a gram-negative, facultative anaerobic Fe(III) reducer and used ferric ion as a terminal electron acceptor for the oxidation of organic compounds to $CO_{2}$ or other oxidized metabolites. The ability of reducing activity and utilization of various electron acceptors and donors for S. putrefaciens DK-1 were investigated. S. putrefaciens DK-1 was capable of using a wide variety of electron acceptor, including $NO_{3}^{-}$, Fe(III), AQDS, and Mn(IV). However, its ability to utilize electron donors was limited. Lactate and formate were used as electron donors but acetate and toluene were not used. Fe(III) reduction of S. putrefaciens DK-l was inhibited by the presence of either $NO_{3}^{-}$ or $NO_{2}^{-}$. Further S. putrefaciens DK-1 used humic acid as an electron acceptor and humic acid was re-oxidized by nitrate. Environmental samples showing the Fe(III)-reducing activity were used to investigate effects of the limiting factors such as carbon, nitrogen and phosphorus on the Fe(III) reducing bacteria. The highest Fe (III) reducing activity was measured, when lactate as a carbon source and S. putrefaciens DK-1 as an Fe(III) reducer added in untreated sediment samples of Cheon-ho and Dae-ho reservoirs.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.04a
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• pp.14-14
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• 2018

This Camptotheca acuminata Decne. (CA), belonging to Nyssaceae, is a deciduous tree. and has been used as Traditional Chinese medicine since ancient times. The CA produces camptothecin a natural indole alkaloid, and reported to have anti-cancer effects. But the studies on biological activities of CA leaves are insufficient. Therefore, this study confirmed various biological activities such as antioxidant, antidiabetic, anticancer, antiinflammatory and metabolism analysis by HPLC-MS/MS of CA leaves. The $RC_{50}$ values of DPPH radical scavenging activity of ethyl acetate fraction, n-Butanol fraction, methanol extraction, water fraction and n-Hexane fraction were $12.23{\pm}0.01$, $15.93{\pm}0.42$, $55.12{\pm}0.45$, $56.29{\pm}4.15$ and $427.29{\pm}6.13ug/mL$, respectively. The $IC_{50}$ values of ${\alpha}$-glucosidase inhibitory activity of ethyl acetate fraction, n-Butanol fraction, methanol extraction, n-Hexane fraction and water fraction were $24.29{\pm}0.14$, $47.86{\pm}0.45$, $54.23{\pm}1.21$ $466.76{\pm}2.21$ and $623.91{\pm}9.67ug/mL$, respectively. The nitric oxide release activity of n-Hexane fraction, methanol extraction, ethyl acetate fraction, water fraction and n-Butanol fraction were $31.49{\pm}5.74$, $29.79{\pm}0.71$, $26.89{\pm}0.71$, $8.24{\pm}5.83$ and $7.75{\pm}4.08%$ at 25 ug/mL, respectively. The anti-cancer activity of n-Hexane fraction, methanol extraction, ethyl acetate fraction, water fraction and n-Butanol fraction were $31.49{\pm}5.74$, $29.79{\pm}0.71$, $26.89{\pm}0.71$, $8.24{\pm}5.83$ and $7.75{\pm}4.08%$ at 25 ug/mL, respectively. The ethyl acetate fraction activities showed higher biological activities than other fractions. Thus, Additional studies were conducted using ethyl acetate fraction. Metabolite analysis was performed using a LCMS-8040 triple quadrupole mass spectrometer. As a result, Five compounds (1-5) were identified in the ethyl acetate fraction of the CA leave. The identification of these compounds was generated by the analysis of fragmentation methods of the negative and positive ion modes. Five compounds were identified as gallic acid (1), chlorogenic acid (2), isoquercetin (3), astragalin (4) and camptothecin (5). These results suggest that the CA leave can be used for functional materials.