• Title/Summary/Keyword: fnr

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A Study on Nitrogen and Phosphorus Removal in FNR Process (FNR process를 이용한 하수처리장의 질소.인의 제거에 관한 연구)

  • Cho Il-Hyoung;Lee Nae-Hyun;Lee Seung-Mok;Kim Young-Kyu
    • Journal of Environmental Science International
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    • v.15 no.6
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    • pp.571-577
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    • 2006
  • This study make a comparison between the phosphorus removal performance of FNR(Ferrous Nutrient Removal) process and A/O process by the laboratory experiments. For simultaneous removal of phosphorus, iron electrolysis was combined with oxic tank. Iron precipitation reactor on the electrochemical behaviors of phosphorus in the iron bed. The phosphorus removal in FNR process was more than A/O process. Iron salts produced by iron electrolysis might help to remove COD and nitrogen. And the demanded longer SRT is the more removes the removes COD, nitrogen, and phosphorus. Also, FNR process of sludge quantity more reduce than A/O process to input cohesive agents.

Changes of PBP Quantity and FNR Activity by Light Wavelengths in Anabaena variabilis (光波長에 따른 Anabaena variabilis 의 Phycobiliprotein 含量 및 FNR 活性度 變化)

  • Kim, Jung-Suk;Chang, Nam-Kee
    • The Korean Journal of Ecology
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    • v.14 no.1
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    • pp.87-99
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    • 1991
  • Changes of phycobiliproteins(PBP) quantity and ferredoxin-NADP reductase(FNR) activity were investigated in various light illuminated cyanobacteria, Anabaena variabilis. PBP components were increased under blue light illumination, whereas decreased under red light illumination. PBP contents were twofolds in blue light than in red light. In view of the PBP composition, allophycocyanin(APC) in red light was higher 5.5% and phycoerythrocyanin(PEC) in blue light was higher 2.2% than in white light-illuminated PBP. It was suggested that PBP changes in bule light be the results of regulation of photosysthetic efficiency and protection of photosystem, whereas PBP changes in red light be effected by adaptation of adequate harvesting of light energy in photosystem. Changes of FNR activity were highest in red light, and sequenced lower to blue light and green light. It means that light-dependent production rate of NADP is the highest in red light. The difference of values was larger than that of values in comparison of red and blue light. It was suggested that increasing of FNR activity be due not to the function of isozyme, but to the synthesis of enzymes. Because of NAD/NADP regulation-effect to metabolism, it was considered that FNR activity might influence the metabolism indirectly and explain the probability of regulation in pathways of key enzyme activation. FNR activity was directly proportional to intensity of light. Optimum temperature and pH were about 25℃ and 7.5, respectively.

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Intrusion Detection System for In-Vehicle Network to Improve Detection Performance Considering Attack Counts and Attack Types (공격 횟수와 공격 유형을 고려하여 탐지 성능을 개선한 차량 내 네트워크의 침입 탐지 시스템)

  • Hyunchul, Im;Donghyeon, Lee;Seongsoo, Lee
    • Journal of IKEEE
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    • v.26 no.4
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    • pp.622-627
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    • 2022
  • This paper proposes an intrusion detection system for in-vehicle network to improve detection performance considering attack counts and attack types. In intrusion detection system, both FNR (False Negative Rate), where intrusion frame is misjudged as normal frame, and FPR (False Positive Rate), where normal frame is misjudged as intrusion frame, seriously affect vechicle safety. This paper proposes a novel intrusion detection algorithm to improve both FNR and FPR, where data frame previously detected as intrusion above certain attack counts is automatically detected as intrusion and the automatic intrusion detection method is adaptively applied according to attack types. From the simulation results, the propsoed method effectively improve both FNR and FPR in DoS(Denial of Service) attack and spoofing attack.

Metabolic Characterization of Lactic Acid Bacterium Lactococcus garvieae sk11, Capable of Reducing Ferric Iron, Nitrate, and Fumarate

  • Yun, Su-Hee;Hwang, Tae-Sik;Park, Doo-Hyun
    • Journal of Microbiology and Biotechnology
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    • v.17 no.2
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    • pp.218-225
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    • 2007
  • A lactic acid bacterium capable of anaerobic respiration was isolated from soil with ferric iron-containing glucose basal medium and identified as L. garvieae by using 16S rDNA sequence homology. The isolate reduced ferric iron, nitrate, and fumarate to ferrous iron, nitrite, and succinate, respectively, under anaerobic $N_2$ atmosphere. Growth of the isolate was increased about 30-39% in glucose basal medium containing nitrate and fumarate, but not in the medium containing ferric iron. Specifically, metabolic reduction of nitrate and fumarate is thought to be controlled by the specific genes fnr, encoding FNR-like protein, and nir, regulating fumarate-nitrate reductase. Reduction activity of ferric iron by the isolate was estimated physiologically, enzymologically, and electrochemically. The results obtained led us to propose that the isolate metabolized nitrate and fumarate as an electron acceptor and has specific enzymes capable of reducing ferric iron in coupling with anaerobic respiration.

Design and Implementation of a Trajectory-based Index Structure for Moving Objects on a Spatial Network (공간 네트워크상의 이동객체를 위한 궤적기반 색인구조의 설계 및 구현)

  • Um, Jung-Ho;Chang, Jae-Woo
    • Journal of KIISE:Databases
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    • v.35 no.2
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    • pp.169-181
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    • 2008
  • Because moving objects usually move on spatial networks, efficient trajectory index structures are required to achieve good retrieval performance on their trajectories. However, there has been little research on trajectory index structures for spatial networks such as FNR-tree and MON-tree. But, because FNR-tree and MON-tree are stored by the unit of the moving object's segment, they can't support the whole moving objects' trajectory. In this paper, we propose an efficient trajectory index structure, named Trajectory of Moving objects on Network Tree(TMN Tree), for moving objects. For this, we divide moving object data into spatial and temporal attribute, and preserve moving objects' trajectory. Then, we design index structure which supports not only range query but trajectory query. In addition, we divide user queries into spatio-temporal area based trajectory query, similar-trajectory query, and k-nearest neighbor query. We propose query processing algorithms to support them. Finally, we show that our trajectory index structure outperforms existing tree structures like FNR-Tree and MON-Tree.

Analysis of the orf 282 Gene and Its Function in Rhodobacter sphaeroide 2.4.1 (R. sphaeroides 에서의 orf282 유전자의 분석과 이들의 기능)

  • Son, Myung-Hwa;Lee, Sang-Joon
    • Journal of Life Science
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    • v.22 no.8
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    • pp.1009-1017
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    • 2012
  • The orf282 gene of Rhodobacter sphaeroides is located between the ccoNOQP operon encoding $cbb_3$ terminal oxidase and the fnrL gene encoding an anaerobic activator, FnrL. Its function remains unknown. In an attempt to reveal the function of the orf282 gene, we disrupted the gene by deleting a portion of the orf282 gene and constructed an orf282-knockout mutant. Two FnrL binding sites were found to be located upstream of orf282, and it was demonstrated that orf282 is positively regulated by FnrL. The orf282 gene is not involved in the regulation of spectral complex formation. The $cbb_3$ oxidase activity detected in the orf282 mutant was comparable to that in the wild-type sample, indicating that the orf282 gene is not involved in the regulation of the ccoNOQP operon and the biosynthesis of the cbb3 cytochrome c oxidase. The elevated promoter activity of the nifH and nifA genes, which are the structural genes of nitrogenase and its regulator, respectively, in the orf282 mutant, suggests that the orf282 gene product acts as a negative effector for nifH and nifA expression.

Fnr, NarL and NarP Regulation and Time Course Expression of Escherichia coli aeg-46.5 Gene

  • Ahn, Ju-Hyuk;Choe, Mu-Hyeon
    • BMB Reports
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    • v.29 no.1
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    • pp.88-91
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    • 1996
  • The anaerobically expressed gene aeg-46.5, which had been identified by the operon fusion technique with a hybrid bacteriophage of ${\lambda}$ and Mu, ${\lambda}$placMu53, was studied for its expression pattern and growth. The expression of aeg-46.5 was studied in the wild-type cell and mutant cells that have mutation (s) in the control gene of anaerobic respiration (fnr) and nitrate response (narL and narP). The ${\beta}$-galactosidase reporter gene showed maximum expression in narL host after two hours of aerobic to anaerobic switch in M9-Glc-nitrate medium. Both 40 mM and 100 mM concentrations of nitrate ion in the medium had little effect on expression level. We propose that aeg-46.5 is subject to multiple regulations of anaerobic activation by Fnr, nitrate activation by NarP and repression mediated by NarL.

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Trajectory Index Structure based on Signatures for Moving Objects on a Spatial Network (공간 네트워크 상의 이동객체를 위한 시그니처 기반의 궤적 색인구조)

  • Kim, Young-Jin;Kim, Young-Chang;Chang, Jae-Woo;Sim, Chun-Bo
    • Journal of Korea Spatial Information System Society
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    • v.10 no.3
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    • pp.1-18
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    • 2008
  • Because we can usually get many information through analyzing trajectories of moving objects on spatial networks, efficient trajectory index structures are required to achieve good retrieval performance on their trajectories. However, there has been little research on trajectory index structures for spatial networks such as FNR-tree and MON-tree. Also, because FNR-tree and MON-tree store the segment unit of moving objects, they can't support the trajectory of whole moving objects. In this paper, we propose an efficient trajectory index structures based on signatures on a spatial network, named SigMO-Tree. For this, we divide moving object data into spatial and temporal attributes, and design an index structure which supports not only range query but trajectory query by preserving the whole trajectory of moving objects. In addition, we divide user queries into trajectory query based on spatio-temporal area and similar-tralectory query, and propose query processing algorithms to support them. The algorithm uses a signature file in order to retrieve candidate trajectories efficiently Finally, we show from our performance analysis that our trajectory index structure outperforms the existing index structures like FNR-Tree and MON-Tree.

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A Study on Phosphorus Removal Effects Per Iron Surface Area in FNR Process (철전기분해장치(FNR)에서 철판의 표면적이 인제거에 미친 영향에 관한 연구)

  • Kim, Young-Gyu
    • Journal of Environmental Health Sciences
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    • v.38 no.6
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    • pp.568-574
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    • 2012
  • Objectives: The purpose of this experiment is to understand the phosphorus removal ratio effects of iron plates per unit of surface area through the iron electrolysis system, which consists of an anoxic basin, aerobic basin, and iron precipitation apparatus. Methods: Iron electrolysis, which uses an iron precipitation reactor in anoxic and oxic basins, consisted of iron plates with total areas of 400 $cm^2$, 300 $cm^2$ and 200 $cm^2$ respectively. The FNR process was operated with a hydraulic retention time and a sludge retention time of 12 hours and three days, respectively. Wastewater used in the experiments was prepared by dissolving $KH_2PO_4$ in influent water. Results: The iron plates 400 $cm^2$ (16.6 $mA/cm^2$), 300 $cm^2$ (13.3 $mA/cm^2$) and 200 $cm^2$ (7.3 $mA/cm^2$) in surface area in the phosphorus reactor had respective phosphorus of 2.4 mg/l, 2.7 mg/l and 3.2 mg/l in the effluent and phosphorus removal respective efficiencies of 90.3%, 89.1% and 87.1%. The effluent in the reactor, where the iron plate was not used, had relatively very low phosphorus removal efficiency showing phosphorus concentration of 15.3 mg/l and a phosphorus removal efficiency about 38.3%. Phosphorus removal per ferrous was 0.472 mgP/mgFe in the iron electrolysis system where the surface area of iron was low. Phosphorus pollution load per active surface area and the phosphorus removal efficiency had an interrelation of RE = -0.27LS + 89.0 (r = 0.85). Conclusion: With larger iron plate surface area, the elution of iron concentration and phosphorus removal efficiency was higher. The removal efficiency of phosphorus has decreased by increasing the initial phosphate concentration in the iron electrodes. This shows a tendency of decreasing phosphorus removal efficiency because of decreasing of iron deposition as the phosphorus pollution load per active surface area increases.