• Korean Journal of Microbiology
• /
• v.38 no.2
• /
• pp.113-118
• /
• 2002

Laboratory experiments were aimed to evaluate the effect of nitrate as a electron acceptor during the biological phosphorus uptake and to investigate the microbial community. Anaerobic-anoxic sequencing batch reactor (SBR) compared the removal behaviour to anaerobic-oxic SBR, both SBRs maintained lower effluent quality with 1.0 mgp/1. Anaerobic-anoxic SBR was able to remove additional 5.0 to 7.0 mg (P+N)/ι than other biological nutrient removal (BM) system. Therefore, it was proposed that the anaerobic-anoxic SBR was more effective at weak sewage. From the results of the maicrobial community analysis, it can be inferred that denitrifying bacteria and polyphosphate accumulating bacteria coexist in anaerobic-anoxic SBR during stable condition for removing the nitrogen and phosphorus. Particularly, it was suggested that the Zoogloea ramigera in the $\beta$-subclass of proteobacteria and the Alcaligenes defragrans of the Rhodocyclus group in the $\beta$-subclass of proteobacteria played a major role for removing the nitrogen and phosphorus as dPAOs (denitrifying phosphate accumulating organisms).

• Journal of Ginseng Research
• /
• v.41 no.1
• /
• pp.10-22
• /
• 2017

Background: Asian ginseng and American ginseng are functional foods that share a close genetic relationship and are well-known worldwide. This article aims to investigate the correlation between morphological characteristics and the inherent quality of Asian and American ginsengs. Methods: In this study, an ultra-HPLC-quadrupole/time-of-flight MS (UHPLC-Q/TOF-MS) method was established for the quantitative analysis of 45 ginseng samples. The method developed for determination was precise and accurate. Results: The results showed that Asian ginseng samples with the same growing time (with the same or similar number of stem scars) that had a thinner main root, a longer rhizome and more branch roots contained greater amounts of ginsenosides. For American ginseng, two tendencies were observed in the relationship between the diameter of the main root and contents of ginsenosides. One tendency was that samples with thinner main roots tended to contain higher levels of ginsenosides, which was observed in the samples sold under the commercial name pao-shen. Another tendency was that samples with thicker main roots contained higher contents of ginsenosides, which was observed in the samples sold under the commercial name pao-mian, as well as in samples of American ginseng cultivated in Jilin, China. Conclusion: An approach using ultra-HPLC-quadrupole/time-of-flight MS was successfully established to link morphology and active components for evaluating the quality of Asian and American ginsengs. Clear correlation between visible morphological features and quality of Asian and American ginsengs was found. People can see the difference; this means consumers and vendors can evaluate ginseng by themselves.

• The Research Journal of the Costume Culture
• /
• v.29 no.2
• /
• pp.204-221
• /
• 2021

The morning ritual was a rite whereby a morning audience with the emperor was held for feudal lords sovereigns and subjects living in the precincts, monarchs or foreign envoys of the outskirts of the capital, and other ethnic group. Distinction between the main and subordinate rituals, changes in the ceremony according to the times, and the position or rank of those participating in the rite, were factors that directly affected the costumes worn for ritual. Accordingly, in this paper, the costumes worn by members of the Ming dynasty (emperor, prince imperial, prince) were examined in terms of the period and detailed ceremonies with a focus on the morning ritual and costume systems presented in the official historical records. Through this study, only Mian-fu (冕服) and Pi-bian-fu (皮弁服) were defined by the costume system ase costumes worn in the morning ritual. However, through comparative analysis with the morning ritual system, it was confirmed that Tongtian-guan-fu (通天冠服), Yishan-guan-fu (翼善冠服), and Bianfu (便服: slightly casual wear) were also worn. It is worth noting that the color of Gunlong-pao (袞龍袍) was differentiated according to status; the Emperor wore yellow, the Prince Imperial and lower levels wore red, which was the traditional perception of academia. However, following confirmation of the custom costume for the morning ritual, it was confirmed that the color of this differentiation appeared during the 3rd year of Emperor Yongle of Ming (1305). Previously five traditional colors (blue, red, yellow, white, and black) were used for the season.

• Publications of The Korean Astronomical Society
• /
• v.36 no.2
• /
• pp.37-45
• /
• 2021

We have analyzed 42 research papers regarding on the solar astronomy written by North Korea scientists to investigate the current status of astronomical activities in North Korea. The papers are surveyed from the 'Bulletin of Astronomy', the 'Physics', the 'Bulletin of Academy of Science', and the 'Natural Science' in North Korea, and SCI journals. In addition, we refer to the presentation material announced in the 2015 IAU by director of Pyongyang Astronomical Observatory (PAO) and the 2013 OAD/IAU reports. We have analyzed the papers statistically according to three criteria such as research subject, research field, and research members. The main research subjects are the sunspot (28%), observation system (21%), and space environments (19%). The research fields are distributed with data analysis (50%), numerical method (29%), and instrument development (21%). There have been 25 and 9 researchers in the solar astronomy and space environment, respectively since 1995. North Korea's solar research activities were also investigated in three area: instrument, solar physics, and international research linkage. PAO has operated two of sunspot telescope and solar horizontal telescope for spectroscopy and polarimetry, but there is no specific information on solar radio telescopes. North Korea has cooperated in solar research with Europe and China. We expect that the results of this study will be used as useful resource in supporting astronomical cooperation between South and North Korea in the future.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
• /
• 2002.10b
• /
• pp.347-348
• /
• 2002

The numbers of synthetic greases have been developed with synthetic oils because of their excellent performance factors including thermal/oxidation stability, low-temperature fluidity and plastic compatibility. Long life under high-temperature condition and excellent low-temperature fluidity are required to serve as grease for bearings of engine room electrical component. As many plastics are used in place of metals for the purpose of weight saving, synthetic hydrocarbon grease is in use to avoid adverse effect on plastics. Other various special synthetic greases are also in use depending on specific requirements like conductivity and vacuum condition.

• Bulletin of the Korean Chemical Society
• /
• v.33 no.8
• /
• pp.2592-2596
• /
• 2012

Cysteine capped silver nanoparticles (Cys-AgNPs) have been synthesized by employing electrochemically active biofilm (EAB), $AgNO_3$ as precursor and sodium acetate as electron donor in aqueous solution at $30^{\circ}C$. Cys-AgNPs of 5-10 nm were synthesized and characterized by UV-Vis, FT-IR, XRD and TEM. Capping of the silver nanoparticles with cysteine provides stability to nanoparticles by a thiolate bond between the amino acid and the nanoparticle surface and hydrogen bonding among the Cys-AgNPs. In addition, the antibacterial effects of as-synthesized Cys-AgNPs have been tested against two pathogenic bacteria Escherichia coli (O157:H7) and Pseudomonas aeruginosa (PAO1). The results demonstrate that the as-synthesized Cys-AgNPs can proficiently inhibit the growth and multiplication of E. coli and P. aeruginosa.

• BMB Reports
• /
• v.38 no.2
• /
• pp.191-197
• /
• 2005

Although the human genome has been nearly completely sequenced, the functions and the roles of the vast majority of the genes, and the influences of single nucleotide polymorphisms (SNPs) in these genes are not entirely known. A modified mutation detection method was developed for large-scale cloning of the possible SNPs between tumor and normal cells for facilitating the identification of genetic factors that associated with cancer formation and progression. The method involves hybridization of restriction enzyme-cut chromosomal DNA, cleavage and modification of the sites of differences by enzymes, and differential cloning of sequence variations with a designed vector. Experimental validations of the presence and location of sequence variations in the isolated clones by PCR and DNA sequencing support the capability of this method in identifying sequence differences between tumor cells and normal cells.

• Journal of Microbiology and Biotechnology
• /
• v.15 no.6
• /
• pp.1368-1376
• /
• 2005

Pseudomonas aeruginosa produces a variety of bacteriocidal substances including pyocins that are active against the same species, but their physiological roles are relatively unknown. Here, we profiled the bacteriocidal activities in the culture supernatants of various P. aeruginosa isolates and describe the competitive growth advantages of strains PAO1 and PA14 over some strains including PAK, which are sensitive to their bacteriocidal activities. These findings suggest that the factors governing the production of pyocins and the resistance to them play important roles in controlling P. aeruginosa populations in its local environments.

• Journal of Plant Biology
• /
• v.32 no.4
• /
• pp.285-292
• /
• 1989

The intracellular localizations of polyamines and their related enzymes were investigated from young spinach leaves. Polyamines were present in all parts of plant cells, both in the subcellular organelles and in the soluble fraction of cytoplasm, however, polyamines were mainly located in the cytosolic fraction. Most activities of L-arginine decarboxylase(ADC) and L-ornithine decarboxylase(ODC), two important enzymes of putrescine and polyamine biosynthesis, were detected in cytosol fraction, while in subcellular organelles the activities were very low. Activities of diamine oxidase(DAO) and polyamine oxidase(PAO), the catabolic enzyme of diamine and polyamine, were not detected in spinach leaves. It was suggested that polyamines and their related synthetic enzymes were located in the soluble fraction of cytoplasm.

• Proceedings of the Korean Environmental Sciences Society Conference
• /
• 2007.05a
• /
• pp.339-345
• /
• 2007

이번 연구에서는 pH 조작이 어려운 소규모 하수 처리장에서의 BNR 슬러지의 접종으로 인한 SBR start-up시 영양 염류 제거 특성 및 변화를 관찰 하였다. 1) 글루코즈를 탄소원으로 사용한 유기물 제거에 있어서 모두 85%이상의 높은 제거 효율을 보였으나 BNR 슬러지 접종 비율이나 유무에 따른 SBR의 유기물 제거에 미치는 영향은 미비한 것으로 나타났다. 2) 유입비율에 따라 암모니아 제거 효율은 BNR 슬러지 첨가 유무에 따라 바뀌었으며, 비율에 상관없이 첨가된 반응조는 7일 이내 $82{\sim}98%$에 달하는 제거율을 보였다. 3) 인 제거효율에 있어서는 유입비율에 따라 인 제거 효율이 증가하였으며, 첨가와 미첨가의 차이는 25%이상의 인 방출량 차이를 나타내었다. 4) 첨가한 BNR 슬러지의 비율이 전체의 40%이상일 때는 50%일 때와 큰 차이를 보이지 못했다. 5) FISH를 통하여 미생물 군집을 확인하였고 각 미생물들 간의 상대적인 비율과 heterotroph의 급격한 증식을 확인할 수 있었다. 6) pH, DO, ORP graph를 통한 Reactor의 실시간 조정 가능성을 볼 수 있었다. 7) BNR 슬러지를 접종하지 않을 경우, PAOs와 질산화 미생물의 성장이 더뎌 영양염류 제거가 어려웠다.