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Bioleaching of Mn(II) from Manganese Nodules by Bacillus sp. MR2 (Bacillus sp. MR2에 의한 망간단괴의 생물용출)

  • Choi, Sung-Chan;Lee, Ga-Hwa;Lee, Hong-Keum
    • Korean Journal of Microbiology
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    • v.45 no.4
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    • pp.411-415
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    • 2009
  • Some microorganisms are capable of leaching Mn(II) from nonsulfidic manganese ores indirectly via nonenzymatic processes. Such reductive dissolution requires organic substrates, such as glucose, sucrose, or galactose, as a source of carbon and energy for microbial growth. This study investigated characteristics of Mn(II) leaching from manganese nodules by using heterotrophic Bacillus sp. strain MR2 provided with corn starch as a less-expensive substrate. Leaching of Mn(II) at 25.6 g Mn(II) $kg^{-1}$ nodule $day^{-1}$ was accompanied with cell growth, but part of the produced Mn(II) re-adsorbed onto residual $MnO_2$ particles after 24 h. Direct contact of cells to manganese nodule was not necessary as a separation between them with a dialysis tube produced similar amount [24.6 g Mn(II) $kg^{-1}$ nodule $day^{-1}$]. These results indicated an involvement of extracellular diffusible compound(s) during Mn(II) leaching by strain MR2. In order to optimize a leaching process we tested factors that influence the reaction, and the most efficient conditions were $25\sim35^{\circ}C$, pH 5~7, inoculum density of 1.5~2.5% (v/v), pulp density of 2~3 g/L, and particle size <75 ${\mu}m$. Although Mn(II) leaching was enhanced as particle size decrease, we suggest <212 ${\mu}m$ as a proper size range since more grinding means more energy consumption The results would help for the improvement of bioleaching of manganese nodule as a less expensive, energy-efficient, and environment-friendly technology as compared to the existing physicochemical metal recovery technologies.

Long-tenn Evaluation of Extruded Pellet Diets Compared to Raw Fish Moist Pellet Diet for Growing Flounder, Paralichthys olivaceus (넙치 미성어 건조 배합사료 및 습사료의 장기사육 평가)

  • Kim Kang-Woong;Kang Yong Jin;Kim Kyong-Min;Lee Hae Young;Kim Kyoung-Duck;Bai Sungchul C.
    • Journal of Aquaculture
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    • v.18 no.4
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    • pp.225-230
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    • 2005
  • This experiment was conducted to compare the effects of extruded pellets and raw fish-based pellet on olive flounder Paralichthys. olivaceus. Six diets were prepared for this study: two formulated extruded pellets (FEP1 & FEP2), three commercially available extruded pellets (CEP1, CEP2 & CEP3) and moist pellet (MP). Weight gain offish fed FEP1 and CEP3 were significantly higher (P<0.05) than those of fish fed FEP2, CEP1, CEP2 and MP, while that of fish fed MP was not significantly different (f<0.05) from those of fish fed the FEP2, CEP1 and CEP2. Feed efficiency of fish fed CEP2 was significantly lower (P<0.05) than those of fish fed FEP1, FEP2, CEP1, CEP3 and MP. There was no significant difference in protein efficiency ratio and hepatosomatic index between fish fed FEP1 and CEP3, and among fish fed FEP2, CEP1 and CEP2. There was no significant difference in condition factor among fish fed the FEP1 and CEP3, and between fish fed FEP2, CTP1 and MP. However, fish fed MP had a lower survival rate than fish fed the other five EP These results suggest that diet FEPl could be developed to replace MP for the owing stage of flounder without adverse effects on growth performance.

The Estimation Model of an Origin-Destination Matrix from Traffic Counts Using a Conjugate Gradient Method (Conjugate Gradient 기법을 이용한 관측교통량 기반 기종점 OD행렬 추정 모형 개발)

  • Lee, Heon-Ju;Lee, Seung-Jae
    • Journal of Korean Society of Transportation
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    • v.22 no.1 s.72
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    • pp.43-62
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    • 2004
  • Conventionally the estimation method of the origin-destination Matrix has been developed by implementing the expansion of sampled data obtained from roadside interview and household travel survey. In the survey process, the bigger the sample size is, the higher the level of limitation, due to taking time for an error test for a cost and a time. Estimating the O-D matrix from observed traffic count data has been applied as methods of over-coming this limitation, and a gradient model is known as one of the most popular techniques. However, in case of the gradient model, although it may be capable of minimizing the error between the observed and estimated traffic volumes, a prior O-D matrix structure cannot maintained exactly. That is to say, unwanted changes may be occurred. For this reason, this study adopts a conjugate gradient algorithm to take into account two factors: estimation of the O-D matrix from the conjugate gradient algorithm while reflecting the prior O-D matrix structure maintained. This development of the O-D matrix estimation model is to minimize the error between observed and estimated traffic volumes. This study validates the model using the simple network, and then applies it to a large scale network. There are several findings through the tests. First, as the consequence of consistency, it is apparent that the upper level of this model plays a key role by the internal relationship with lower level. Secondly, as the respect of estimation precision, the estimation error is lied within the tolerance interval. Furthermore, the structure of the estimated O-D matrix has not changed too much, and even still has conserved some attributes.

Analysis of media trends related to spent nuclear fuel treatment technology using text mining techniques (텍스트마이닝 기법을 활용한 사용후핵연료 건식처리기술 관련 언론 동향 분석)

  • Jeong, Ji-Song;Kim, Ho-Dong
    • Journal of Intelligence and Information Systems
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    • v.27 no.2
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    • pp.33-54
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    • 2021
  • With the fourth industrial revolution and the arrival of the New Normal era due to Corona, the importance of Non-contact technologies such as artificial intelligence and big data research has been increasing. Convergent research is being conducted in earnest to keep up with these research trends, but not many studies have been conducted in the area of nuclear research using artificial intelligence and big data-related technologies such as natural language processing and text mining analysis. This study was conducted to confirm the applicability of data science analysis techniques to the field of nuclear research. Furthermore, the study of identifying trends in nuclear spent fuel recognition is critical in terms of being able to determine directions to nuclear industry policies and respond in advance to changes in industrial policies. For those reasons, this study conducted a media trend analysis of pyroprocessing, a spent nuclear fuel treatment technology. We objectively analyze changes in media perception of spent nuclear fuel dry treatment techniques by applying text mining analysis techniques. Text data specializing in Naver's web news articles, including the keywords "Pyroprocessing" and "Sodium Cooled Reactor," were collected through Python code to identify changes in perception over time. The analysis period was set from 2007 to 2020, when the first article was published, and detailed and multi-layered analysis of text data was carried out through analysis methods such as word cloud writing based on frequency analysis, TF-IDF and degree centrality calculation. Analysis of the frequency of the keyword showed that there was a change in media perception of spent nuclear fuel dry treatment technology in the mid-2010s, which was influenced by the Gyeongju earthquake in 2016 and the implementation of the new government's energy conversion policy in 2017. Therefore, trend analysis was conducted based on the corresponding time period, and word frequency analysis, TF-IDF, degree centrality values, and semantic network graphs were derived. Studies show that before the 2010s, media perception of spent nuclear fuel dry treatment technology was diplomatic and positive. However, over time, the frequency of keywords such as "safety", "reexamination", "disposal", and "disassembly" has increased, indicating that the sustainability of spent nuclear fuel dry treatment technology is being seriously considered. It was confirmed that social awareness also changed as spent nuclear fuel dry treatment technology, which was recognized as a political and diplomatic technology, became ambiguous due to changes in domestic policy. This means that domestic policy changes such as nuclear power policy have a greater impact on media perceptions than issues of "spent nuclear fuel processing technology" itself. This seems to be because nuclear policy is a socially more discussed and public-friendly topic than spent nuclear fuel. Therefore, in order to improve social awareness of spent nuclear fuel processing technology, it would be necessary to provide sufficient information about this, and linking it to nuclear policy issues would also be a good idea. In addition, the study highlighted the importance of social science research in nuclear power. It is necessary to apply the social sciences sector widely to the nuclear engineering sector, and considering national policy changes, we could confirm that the nuclear industry would be sustainable. However, this study has limitations that it has applied big data analysis methods only to detailed research areas such as "Pyroprocessing," a spent nuclear fuel dry processing technology. Furthermore, there was no clear basis for the cause of the change in social perception, and only news articles were analyzed to determine social perception. Considering future comments, it is expected that more reliable results will be produced and efficiently used in the field of nuclear policy research if a media trend analysis study on nuclear power is conducted. Recently, the development of uncontact-related technologies such as artificial intelligence and big data research is accelerating in the wake of the recent arrival of the New Normal era caused by corona. Convergence research is being conducted in earnest in various research fields to follow these research trends, but not many studies have been conducted in the nuclear field with artificial intelligence and big data-related technologies such as natural language processing and text mining analysis. The academic significance of this study is that it was possible to confirm the applicability of data science analysis technology in the field of nuclear research. Furthermore, due to the impact of current government energy policies such as nuclear power plant reductions, re-evaluation of spent fuel treatment technology research is undertaken, and key keyword analysis in the field can contribute to future research orientation. It is important to consider the views of others outside, not just the safety technology and engineering integrity of nuclear power, and further reconsider whether it is appropriate to discuss nuclear engineering technology internally. In addition, if multidisciplinary research on nuclear power is carried out, reasonable alternatives can be prepared to maintain the nuclear industry.

Comparison of Removal Efficiencies in Single and Duplex Ventilation Constructed Wetland Systems for Treating Domestic Sewage (단일 통풍형과 이중 통풍형 인공습지시스템의 하수처리 효율 비교)

  • Seo, Dong-Cheol;Lim, Seok-Cheon;Jo, In-Seong;Lee, Byeong-Ju;Lee, Hong-Jae;Kim, Sang-Don;Lee, Jun-Bae;Cho, Ju-Sik;Heo, Jong-Soo
    • Korean Journal of Environmental Agriculture
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    • v.28 no.3
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    • pp.258-265
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    • 2009
  • To develop environmentally friendly constructed wetlands(CWs) for treating domestic sewage which was produced in farming and fishing village, the efficiency of water treatment at different ventilation systems in the vertical bed, depths of horizontal bed, and sewage loads was investigated. In the vertical bed, BOD and COD by duplex ventilation system were lower than those by single ventilation system. But T-N and T-P concentrations by both ventilation systems in the vertical bed were little different. In the horizontal bed, BOD, COD, T-N and T-P in 1.0 m and 1.3 m depths were little different. To reduce the CWs' area and to improve the pollutant removal efficiencies, the optimum depth of horizontal bed was 1.3 m. In single and duplex ventilation CWs, the removal rate of BOD, COD, SS, T-N and T-P decreased slightly with the sewage load increases. In same sewage load conditions, the removal rates of BOD, COD, SS, T-N and T-P by duplex ventilation CWs were higher than those by single ventilation CWs. In summary, to effectively treat domestic sewage from farming and fishing village, the optimum constructed wetlands would be the duplex ventilation CWs.

The Rusticity and Spirit of Scholars Found at Suwoojae, the Birth House of Garam Byungi Lee (가람(嘉藍) 이병기 생가(李秉岐 生家) 수우재(守愚齋)에서 찾는 소박함과 선비정신)

  • Kim, Jung-Sik;Rho, Jae-Hyun;Kim, Jeong-Moon;Oh, Hyun-Kyung
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.28 no.1
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    • pp.1-11
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    • 2010
  • This study examines the authentic meaning, location, garden layout, and structural characteristics of Suwoojae(守愚齋), the birth house of Garam Byungi Lee, which was the very epitome of the traditional house structure based on literature review, field survey, and the existing measured drawings. The followings explain how rusticity and spirit of scholars, the core concepts of Garam's poetry, were featured in structural and spacial arrangements of Suwoojae as well as its location and physical layout. 1. Suwoojae is enclosed by Cheonho mountain which fans out of Noryoung mountains in East and located on the tail of Yongwha mountain in West. It has proved to be Yangtack Myoungdang according to the Poongsoo theory, Inguljiryoungron; The energy of earth at a certain location results in the better fortune together with the energy emitted from human body. 2. Suwoojae is an official local monument which was built in 1844, late Joesoen Dynasty by Joheung Lee, Garam's grandfather. Some parts of inner-structure connect with the kitchen in the shape of called Gopae. Suwoojae consists of 4 Sarangchae, 3 Gobangchae, and a Jangdokdae behind Anchae. 3. Since inner and outer walls of Suwoojae are distinctly separate from the main structure, its look varies significantly from different angles. Suwoojae, in its entirety, discloses Garam's philosophy, ideas, and ideology on life and the universe. 4. Apricot trees, Japanese-magnolias, aromatic-trees, crape myrtle, white-magnolias, camellia-trees were planted on the left of the walls, and persimmon trees, jujube trees, plum trees, quince trees were at the inner-yard. Especially, trifoliate orange trees a natural monument of Jeonrabukdo draw substantial attention from visitors. 5. The main garden facilities are located in front of Sarangchae: A rectangle pond(14.72m in length and 3.87m in height), the surroundings of the pond and Anchae, rocks that have distinctive shapes. In general, the garden was designed to incorporate the scenery around Suwoojae as a part of its structure and contain the love for nature and aesthetic sense. 6. It seems that the natural surroundings of Suwoojae had helped form motives of Garam's poetry and assisted him in finding subject-matters and identifying the themes of his works. This is well revealed in his poem, Seungwoonjungee.

Cystic Diseases of the Kidney in Children (소아의 낭포성 신질환)

  • Lee Ji-Suk;Rho Kwang-Sik;Kim Ji-Hong;Lee Jae-Seung;Kim Pyung-Kil
    • Childhood Kidney Diseases
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    • v.1 no.2
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    • pp.144-150
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    • 1997
  • Purpose : The kidney is one of the most common sites of cyst formation. Cystic diseases of the kidney are a diverse group of clinicopathologic entities and variable prognosis. They span a wide range of both age of presentation and severity of the renal disease. And many of them are systemic disorders, sharing similar process of cyst formation in other organs. Recently, development of imaging studies has been contributing widely to the diagnosis of the diseases. Treatment, however, is not established satisfactorily. We performed this study to evaluate the occurrence and treatment of cystic diseases of the kidney. Methods : We reviewed retrospectively the medical records of 44 patients with cystic diseases of the kidney in the Department of Pediatrics, during last 11 years. Results : In the 44 patients with cystic diseases of the kidney, 31 patients(71%) had multicystic dysplastic kidney and 11(35%) of them received nephrectomy due to differentiation from neoplasms or severe abdominal distension. Seven patients(16%) had polycystic kidney disease, and all of them were infantile type. Five patients(11%) were diagnosed as having a simple renal cysts. Progression to renal failure was noted in none of the cases. In 14(32%) out of total 44 patients, the diagnosis was made in neonatal or infantile pelted. Conclusion : The incidence of cystic diseases of the kidney appeared very low, but further investigation on their pathogenesis, classification, and indication of treatment is needed.

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Algicidal Characteristics of 1-Alkyl-3-Methylimidazolium Chloride Ionic Liquids to Several Fresh-water Algae (이온성 액체 1-alkyl-3-methylimidazolium chloride계 화합물의 담수조류에 대한 살조활성 특징)

  • Hwang, Hyun-Jin;Kim, Jae-Deog;Choi, Jung-Sup;Kim, Young-Wun;Kim, Jin-Seog
    • Korean Journal of Weed Science
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    • v.30 no.3
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    • pp.233-242
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    • 2010
  • This study was conducted to know that if ionic liquids can be applicable as control agents of harmful algae in water-ecosystem and to find out problems caused by ionic liquid application. Firstly, the differential selectivity of various fresh-water algal species to several 1-alkyl-3-methylimidazolium chloride ionic liquids was investigated. There was a distinct differential response between alkyl chain lengths from butyl to dodecyl and towards the algal organisms : Generally algicidal activity was increased with increase of chain length and among the algae used in this study, Stephanodiscus hantzschii f. tenuis, Oscillatoria tenuis and Spirulina pratensis were most sensitive to 1-dodecyl-3-methylimidazolium chloride (MAIC12), next was Microcystis aeruginosa, and the others were relatively less sensitive to the chemical. The selectivity degree was about ten to twenty times based on the $EC_{80}$ (Effective concentration required for 80% growth inhibition). Secondly, an activity persistence of ionic liquids was investigated in natural mimic condition (using water bottle containing soil-sediments under the greenhouse condition). At the application of $1.0{\mu}g\;mL^{-1}$ of 1-octyl-3-methylimidazolium chloride (MAIC8), the algal growth did not occur at all until 6 days after treatment(DAT) and observed a only little growth at 9 DAT. But the algae grew rapidly after 9 DAT. So at 20 DAT, total chlorophylls was $264.4{\mu}g\;L^{-1}$ and the growth was inhibited by 58.2% compared to untreatment. On the other hand, MAIC12 also had a similar persistence pattern to MAIC8, showing nearly 5 times more activity than MAIC8. At 20 days after $0.2{\mu}g\;mL^{-1}$ application of MAIC12, that is, total chlorophylls was $251.2{\mu}g\;L^{-1}$ and the growth was inhibited by 55.2% compared to untreatment. In summary, 1-alkyl-3-methylimidazolium chloride ionic liquids is likely to be applicable for selective control of harmful algae as potent compounds having long lasting activity. However, the difficulty of degradation seems to be a limiting factor in an eco-friendly application of the compounds.

Eco-friendly and efficient in situ restoration of the constructed sea stream by bioaugmentation of a microbial consortium (복합미생물 생물증강법을 이용한 인공해수하천의 친환경 효율적 현장 수질정화)

  • Yoo, Jangyeon;Kim, In-Soo;Kim, Soo-Hyeon;Ekpeghere, Kalu I.;Chang, Jae-Soo;Park, Young-In;Koh, Sung-Cheol
    • Korean Journal of Microbiology
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    • v.53 no.2
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    • pp.83-96
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    • 2017
  • A constructed sea stream in Yeongdo, Busan, Republic of Korea is mostly static due to the lifted stream bed and tidal characters, and receives domestic wastewater nearby, causing a consistent odor production and water quality degradation. Bioaugmentation of a microbial consortium was proposed as an effective and economical restoration technology to restore the polluted stream. The microbial consortium activated on site was augmented on a periodic basis (7~10 days) into the most polluted site (Site 2) which was chosen considering the pollution level and tidal movement. Physicochemical parameters of water qualities were monitored including pH, temperature, DO, ORP, SS, COD, T-N, and T-P. COD and microbial community analyses of the sediments were also performed. A significant reduction in SS, COD, T-N, and COD (sediment) at Site 2 occurred showing their removal rates 51%, 58% and 27% and 35%, respectively, in 13 months while T-P increased by 47%. In most of the test sites, population densities of sulfate reducing bacterial (SRB) groups (Desulfobacteraceae_uc_s, Desulfobacterales_uc_s, Desulfuromonadaceae_uc_s, Desulfuromonas_g1_uc, and Desulfobacter postgatei) and Anaerolinaeles was observed to generally decrease after the bioaugmentation while those of Gamma-proteobacteria (NOR5-6B_s and NOR5-6A_s), Bacteroidales_uc_s, and Flavobacteriales_uc_s appeared to generally increase. Aerobic microbial communities (Flavobacteriaceae_uc_s) were dominant in St. 4 that showed the highest level of DO and least level of COD. These microbial communities could be used as an indicator organism to monitor the restoration process. The alpha diversity indices (OTUs, Chao1, and Shannon) of microbial communities generally decreased after the augmentation. Fast uniFrac analysis of all the samples of different sites and dates showed that there was a similarity in the microbial community structures regardless of samples as the augmentation advanced in comparison with before- and early bioaugmentation event, indicating occurrence of changing of the indigenous microbial community structures. It was concluded that the bioaugmentation could improve the polluted water quality and simultaneously change the microbial community structures via their niche changes. This in situ remediation technology will contribute to an eco-friendly and economically cleaning up of polluted streams of brine water and freshwater.

Estimation of Urban Heat Island Potential Based on Land Cover Type in Busan Using Landsat-7 ETM+ and AWS Data (Landsat-7 ETM+ 영상과 AWS 자료를 이용한 부산의 토지피복에 따른 여름철 도시열섬포텐셜 산출)

  • Ahn, Ji-Suk;Hwang, Jae-Dong;Park, Myung-Hee;Suh, Young-Sang
    • Journal of the Korean Association of Geographic Information Studies
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    • v.15 no.4
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    • pp.65-77
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    • 2012
  • This study examined changes in land cover for the past 25 years in Busan and subsequently evaluated heat island potential by using land surface temperature and observation temperature data. The results were as below. The urban area of Busan increased by more than 2.5 times for the past 25 years from 1975 to 2000. It was believed that an increase in the pavement area of city within such a short period of time was an unprecedented phenomenon unique to our country. It could be assumed that urban heat island would be worsened through this process. After analyzing the land temperature according to the land cover, it was shown that there were noticeable changes in the temperature of urban & built-up and mountain & forest areas. In particular, the temperature rose to $36{\sim}39^{\circ}C$ in industrial areas during the summer, whereas it went down to $22{\sim}24^{\circ}C$ in the urban areas at whose center there were mountains. It was found that heat island potential according to the level of land cover had various values depending on the conditions of land cover. Among the areas of urbanization, the industrial area's heat island potential is 6 to $8^{\circ}C$, and the residential and commercial area's is $0{\sim}5^{\circ}C$, so it has been found that there is high possibility to induce urban heat islands. Meanwhile, in the forest or agricultural area or the waterside, the heat island potential is $-6{\sim}-3^{\circ}C$. With this study result, it is possible to evaluate the effects of temperature increase according to the urban land use, and it can be used as foundational data to improve urban thermal environment and plan eco-friendly urban development.