• 한국표면공학회지
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• 제32권3호
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• pp.312-316
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• 1999

The interfacial structure of duplex treated AISI 4140 consisting of iron nitride and TiN layer was characterized by optical microscope, SEM and XRD. A black layer was formed from the decomposition of iron nitride during Ti ion bombardment. The black layer was characterized as an a-Fe phase transformed from the iron nitride by XRD. In order to identify the formation mechanism of the black layer, a thermal analysis of iron nitride undertaken by DSC method. As an iron nitride was mostly consisted of ${\gamma}$'-Fe$_4$N and $\varepsilon$-$Fe_3$N phase after plasma nitriding, in this study, a ${\gamma}$'$-Fe_4$N and $\varepsilon$-$Fe_3$N powders were separately prepared by the different processing conditions of gas nitriding of iron powder in the fluidized bed. From the DSC thermal analysis, the phase transformation of ${\gamma}$'$-Fe_4$N, $\varepsilon$-$Fe_3$N was followed the path of transformation; $ \Upsilon{'}-Fe_4$Nlongrightarrow${\gamma}$-Felongrightarrowa-Fe and of $\varepsilon$-$Fe_3$Nlongrightarrow$\varepsilon$-$Fe_{2.5}$ /N+${\gamma}$'$-Fe_4$Nlongrightarrow${\gamma}$'-Fe$_4$Nlongrightarrow${\gamma}$longrightarrowFelongrightarrowalongrightarrowFe, respectively. It explains the reason why the $\varepsilon$ $-Fe_3$N phase disappeared in the first time and then ${\gamma}$'-Fe$_4$N in the formation of the black layer in the duplex coating.

• The Korean Journal of Ecology
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• 제12권1호
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• pp.21-35
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• 1989

It was found that seed germination and seedling growth of selected species were inhibited by phytotoxic substance released from black pine. The longer was the aqueous extraction time of black pine needles, the smaller was the relative germination and growth of the species were inhibited in aqueous leachate and rain leachate as well as in soil underneath the black pine trees. In addition, the growth of lettuce was suppressed in volatile substances from black pine needles. To detect phytotoxic substances of black pine needles, paper chromatography and high performance liquid chromatography were used and fourteen kinds of KDICical compounds were isolated and identified as phenolic acids including benzoic acids. The growth of lettuce was inhibited in the experiment using reagents identical to these KDICical substances and a great inhibition was observed in the concentration of less than 5$\times$ M.

• Ocean Science Journal
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• 제43권2호
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• pp.107-113
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• 2008

Laboratory bioassays were conducted to test the acute toxicity effects of sudden exposure to sodium cyanide (NaCN) on the endogenous rhythm of the oxygen consumption rate (OCR) in the black rockfish Sebastes schlegeli. The OCR of the black rockfish(n = 14, total length = $20.4{\pm}1.16\;cm$, wet weight = $158{\pm}25\;g$) was measured with an automatic intermittent-flow-respirometer. OCR decreased significantly when experimental fish were exposed to NaCN. When exposed to 10 ppb NaCN, fish were able to recover their OCR rhythmic activities. When fish were exposed to 20 ppb, however, the metabolic activity rhythms were not recovered. These results suggest that exposure to NaCN concentrations over 20 ppb cause severe physiological damage to the endogenous rhythms of black rockfish.

• The Plant Pathology Journal
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• 제18권1호
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• pp.54-55
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• 2002

Soaked black rot symptom was observed on the stem of Angelica acutiloba from July to August 2000 at Kumsan, Chungnam in Korea. This disease usually occurred under humid and high temperature conditions. The lesions on the stem appeared as soft rot with brown elliptical spots, which developed into large black spots at a later stage. When the bacterial isolates from the diseased plants were inoculated onto healthy plants by artificial needle prick method, symptoms similar to that observed in the fields developed. According to the cultural characteristics and pathogenicity of the isolates on the host plant the causal bacterium was identified as Xanthomonas campestris. This study proposed that the disease be named "bacterial black stem rot of A. acutiloba"loba".

• Elastomers and Composites
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• 제24권3호
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• pp.193-202
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• 1989

An experimental study of the development of carbon black dispersion by an internal mixer and its characterization is presented. We describe the measurement of carbon black agglomerate size and related characteristics using four different experimental techniques : optical microscopy, scanning elctrion microscopy, surface roughness, and electrical couductivity. The results from these different experiments are compared uning the same carbon black for a series of six different butadiene-styrene copolymers. The results from the different techniques are cross plotted and are critically discussed. It is found that surface but then sharply deteriorate. At subsequent stages of mixing optical microscopy seemed the most reliable measure.

• 미생물학회지
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• 제19권3호
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• pp.108-114
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• 1981

In order to isolate microorganisms which produce antibiotics aganist wheat black rust, some bacteria, molds, and actinomycetes were isolated from soils and screened for the production of antibiptics against wheat black rust. Beacuse wheat black rust-puccinia graminis--is a complete parsitic mold which can't grow in artifical medium, new method for the screening of antibiotic producing microorgsnisms against wheat black rust developed by using live leaves of wheat. With new method, a strain No. $480HS_{20}$ which produces a substnace having strong and Puccinia graminis activity and very narrow antimicrobial spectrum was isolated. the substance produced by the strain No.$480HS_{20}$ had better anti Puccinia graminis activity than any other known antifungal antibotics such as kasurgamycin, balasticidins, actidione, antimycin, ologomycin. And the substance was observed to be very stable at heat and ultraviolet light. The strain was indentified as Bacillus subtilis.

• 천문학회보
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• 제41권2호
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• pp.29.5-30
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• 2016

(1) The correlation between the mass of supermassive black holes (SMBHs) and the properties of their host galaxies suggests that SMBHs and host galaxies are closely linked in their formation and evolution. While the exact origin of their relationship is still under debate, theoretical models often invoke feedback from active galactic nuclei as a crucial mechanism for establishing the BH-host correlation. In the first part of my talk, I will present our efforts to find observational sign of the AGN feedback in young luminous AGNs. (2) While intermediate-mass black hole (IMBH) is thought be cosmologically important class to understand the link between stellar mass black holes and SMBHs, it is extremely rare in the present-day Universe. In the second part of this talk, I will report a Gemini/GMOS-N IFU study of an ultraluminous X-ray source in NGC 5252, which is a possible candidate of an off-nuclear non-stellar black hole.

• 천문학회보
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• 제42권1호
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• pp.27.4-27.4
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• 2017

(1) The correlation between the mass of supermassive black holes (SMBHs) and the properties of their host galaxies suggests that SMBHs and host galaxies are closely linked in their formation and evolution. While the exact origin of their relationship is still under debate, theoretical models often invoke feedback from active galactic nuclei as a crucial mechanism for establishing the BH-host correlation. In the first part of my talk, I will present possible observational biases in the BH-host relation, and methods to overcome these biases. I will also report our efforts to find observational sign of the AGN feedback in high-z young luminous AGNs. (2) While intermediate-mass black hole (IMBH) is thought be cosmologically important class to understand the link between stellar mass black holes and SMBHs, it is extremely rare in the present-day Universe. In the second part of this talk, I will report a Gemini/GMOS-N IFU study of an ultraluminous X-ray source in NGC 5252, which is a possible candidate of an off-nuclear non-stellar black hole.

• 대한수의학회지
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• 제44권2호
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• pp.159-162
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• 2004

We investigated the cytogenetic characteristics of male black-striped field mouse (Apodemus agrarium) in Korea. Chromosome slides were obtained from blood cell cultures which were synchronized with thymidine blocking or not. In the chromosome slide which synchronization with thymidine blocking was employed on, the GTG(G bands by trypsin using Giemsa)-bands of high resolution were observed. The male black-striped field mouse has 48 chromosomes composed 46 autosomes and XY sex chromosomes. The centromeric regions of autosomes were positive to GTG-banding. According to this investigation, thymidine blocking in cell culture process was useful to get lengthened chromosomes. It may be necessary to employ RBG-banding technique to investigate complementary band patterns between R- and G-banding in black-striped field mouse.

• Food Science and Biotechnology
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• 제14권5호
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• pp.672-675
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• 2005

Two anthocyanins were isolated from 1% HCl-20% methanol extracts of KG 97287 black common bean (Phaseolus vulgaris L.) using semipreparative, high-performance liquid chromatography (HPLC). The anthocyanins were identified using a combination of LC/ES-mass spectrometry (MS) and spectroscopic methods of UV-Vis, $^1H-$ and $^{13}C-$ nuclear magnetic resonance (NMR). The chemical structures of these two anthocyanins were elucidated as delphinidin 3-glucoside and petunidin 3-glucoside and their contents in KG 97287 black common bean seed coats were determined to be $2.614{\pm}0.11$ and $0.167{\pm}0.01\;mg/g$, respectively. These contents were lower than reported internationally and we recommend the introduction into Korea of high anthocyanin varieties of black common bean.