• 제목/요약/키워드: CP potential

검색결과 285건 처리시간 4.493초

Cathodic Protection Behavior of Coastal Bridge Structure with Sacrificial Anode Cathodic Protection System (희생양극식 음극방식이 적용된 해안 교량 구조물의 방식거동)

  • Ha, Ji-Myung;Jin, Chung-Kuk;Jeong, Jin-A
    • Corrosion Science and Technology
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    • 제11권6호
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    • pp.242-246
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    • 2012
  • This measurement represents the effectiveness of sacrificial anode cathodic protection (SACP) system in a coastal bridge structure. To verify the cathodic protection (CP) effect, the monitoring sensor (DMS-100) that could measure potential, corrosion rate, current, concrete resistivity, and temperature was embedded. The measurement conducted for three years after CP system was installed. Specifically, due to the fact that fresh water and sea water was repeated in the bridge structure, this bridge structure presented special CP behavior. Measurement factors were CP potential, CP current, concrete resistivity, and depolarization potential. In addition, visual inspection was also carried out. As a result of current and depolarization measurement, CP system was well activated in most piers.

Distribution of Cathodic Protection Potential for Concrete Slab Specimens at Diverse Environmental Conditions

  • Jin, Chung-Kuk;Jeong, Jin-A
    • International Journal of Ocean System Engineering
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    • 제3권2호
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    • pp.90-94
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    • 2013
  • This study represents the recent laboratory results from cathodic protection (CP) system with the use of sacrificial anodes at different environmental conditions (temperature of $10^{\circ}C$ and $40^{\circ}C$). Specimens were slab type with a dimension of $500mm{\times}50mm{\times}100mm$, and concrete cover thickness were 25mm. Zinc mesh and/or bulk type anodes were installed at the center of specimen to confirm the distance that CP system has influences on the specimen to distribute uniform CP current to rebar. Two different kinds of temperature condition were applied to verify the effect of temperature. Experiments were conducted for 60 days, and the distribution of potential and current that supplied from anode to rebar was measured. From the results, CP potential was varied with time, and temperature played an important role in CP potential variations. Current was also changed with time, and current distribution could be improved by installing additional bulk type anode.

Electrochemical Characteristics of Zn-mesh Cathodic Protection Systems in Concrete in Natural Seawater at Elevated Temperature

  • Kim, Ki-Joon;Jung, Jin-A;Lee, Woo-Cheol;Jang, Tae-Seub
    • Corrosion Science and Technology
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    • 제6권6호
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    • pp.269-274
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    • 2007
  • The corrosion of steel in concrete is significant in marine environment. Salt damage is one of the most detrimental causes to concrete bridges and port structures. Especially, the splash and tidal zones around water line are comparatively important in terms of safety and life-time point of view. During the last several decades, cathodic protection (cp) has been commonly accepted as an effective technique for corrosion control in concrete structures. Zn-mesh sacrificial anode has been recently developed and started to apply to the bridge column cp in marine condition. The detailed parameters regarding Zn-mesh cp technique, however, have not well understood so far. This study is to investigate how much Zn-mesh cp influences along the concrete column at elevated temperature. About 100 cm column specimens with eight of 10 cm segment rebars have been used to measure the variation of cp potential with the distance from Zn-mesh anode at both $10^{\circ}C$ and $40^{\circ}C$ in natural seawater. The cp potential change and current diminishment along the column specimens have been discussed for the optimum design of cp by Zn-mesh sacrificial anode.

The effect of temperature and relative humidity on concrete slab specimens with impressed current cathodic protection system

  • Jeong, Jin-A;Jin, Chung-Kuk
    • Journal of Advanced Marine Engineering and Technology
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    • 제37권3호
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    • pp.260-265
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    • 2013
  • Impressed current cathodic protection (ICCP) system is one of the most promising corrosion protection methods. The Effect of ICCP system can be changed at diverse conditions. Particularly, temperature and relative humidity plays a crucial role in CP (Cathodic Protection) effect. Thus, in this study, the influence of temperature and relative humidity on concrete specimens was investigated. Specimens were concrete slab type with a base of $400mm{\times}400mm$ and height of 70mm. To enhance the effect of CP system, seawater was used as an electrolyte. Used anode for ICCP system was mixed metal oxide (MMO) titanium. Test factors were natural potential, CP potential, CP current, and 4-hour depolarization potential. From this study, it could be confirm that CP potential and current were highly influenced by temperature and relative humidity.

Reactivity of RhCp* Complexes Containing Labile Ligands toward Potential Linking Ligands Containing Terminal Thiophene or Furan Rings:Preparation and Structures of [Cp*Rh(L1)Cl2], [Cp*Rh(η2-NO3)(L1)](OTf),and {[Rh(L2)] · (OTf)}[L1 = 1,2-Bis((thiophen-2-yl)methylene)hydrazine); L2 = 1,2-Bis((furan-2-yl)methylene)hydrazine]

  • Lee, Kyung-Eun;Lee, Soon-W.
    • Bulletin of the Korean Chemical Society
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    • 제31권12호
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    • pp.3600-3604
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    • 2010
  • Rhodium(III)-$Cp^*$ complexes containing labile ligands, $[Cp^*RhCl_2]_2$, [$Cp^*Rh({\eta}^2-NO_3)$(OTf)], and $[Cp^*Rh(OH_2)_3](OTf)_2$, reacted with potential linking ligands [$L^1$ = (2-thiophene)-CH=N-N=CH-(2-thiophene); $L^2$ = (2-furan)-CH=N-N=CH-(2-furan)] to give two molecular compounds, [$Cp^*Rh(L^1)Cl_2$] (1) and [$Cp^*Rh({\eta}^2-NO_3)(L^1)$]$(OTf){\cdot}CH_2Cl_2$ ($2{\cdot}CH_2Cl_2$), and one 1-dimensioanl coordination polymer, $\{[Rh(L^2)]{\cdot}(OTf)}_{\infty}$ (3). Whereas one imine nitrogen atom within the ligand is coordinated to the Rh metal in compounds 1 and 2, both nitrogen atoms are bound to two neighboring Rh metals in compound 3 to lead to a 1-D chain polymer.

Bacterial Reverse Mutation Test of CP pharmacopunture (세균을 이용한 CP 약침의 복귀돌연변이 시험)

  • Hwang, Ji Hye;Ku, Jaseung;Jung, Chul
    • The Journal of Korean Medicine
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    • 제41권3호
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    • pp.55-65
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    • 2020
  • Objectives: This study aimed to evaluate the toxicity of CP pharmacopunture using bacterial reverse mutation test. Methods: To determine the mutagenic potential of CP pharmacopunture, histidine requiring Salmonella typhimurium (TA98, TA100, TA1535, and TA1537) and tryptophan requiring Escherichia coli (WP2uvrA, pKM101) strains were used. The negative (normal saline solution) and positive (Sodium azide, 2-Nitrofluorene, 2-Aminoanthracene, 9-Aminoacridine, and 4-Nitroquinoline N-oxide) control groups were used. To determine the dose levels of the main study, a dose range-finding study was conducted. Results: As a results of the dose range-finding study, the growth inhibition by CP pharmacopunture was not evident at any dose levels in the absence and presence of metabolic activation. As a results of the main study, the mean number of revertant colonies was less than twice when compared to the negative control values at all dose levels of the CP pharmacopuncture in the presence and absence of metabolic activation, showing no dose-related increase. In the positive control group, the number of revertant colonies was markedly increased by more than twice when compared to the negative control group. Conclusion: According to the results of this study, CP pharmacopunture did not show any signs of mutagenic potential.

CpG Islands Detector: a Window-based CpG Island Search Tool

  • Kim, Ki-Bong
    • Genomics & Informatics
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    • 제8권1호
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    • pp.58-61
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    • 2010
  • CpG is the pair of nucleotides C and G, appearing successively, in this order, along one DNA strand. It is known that due to biochemical considerations CpG is relatively rare in most DNA sequences. However, in particular subsequences, which are a few hundred to a few thousand nucleotides long, the couple CpG is more frequent. These subsequences, called CpG islands, are known to appear in biologically more significant parts of the genome. The ability to identify CpG islands along a chromosome will therefore help us spot its more significant regions of interest, such as the promoters or 'start' regions of many genes. In this respect, I developed the CpG islands search tool, CpG Islands Detector, which was implemented in JAVA to be run on any platform. The window-based graphical user interface of CpG Islands Detector may facilitate the end user to employ this tool to pinpoint CpG islands in a genomic DNA sequence. In addition, this tool can be used to highlight potential genes in genomic sequences since CpG islands are very often found in the 5' regions of vertebrate genes.

An Analysis of the Protective Potential Distribution against Corrosion for Hull ICCP with Computer simulation (컴퓨터 Simulation을 통한 선체 음극방식(ICCP)의 방식전위분포해석)

  • Im, Gwan-Jin;Kim, Ki-Joon;Lee, Myung-Hoon;Moon, Kyung-Man
    • Proceedings of the Korean Society of Marine Engineers Conference
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    • 한국마린엔지니어링학회 2005년도 전기학술대회논문집
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    • pp.395-400
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    • 2005
  • The ship hull part is always exposed to severe corrosive environments. Therefore, it should be protected in appropriate ways to reduce corrosion problems. So there are two effective methods in order to protect the corrosion of ship hull. One is the paint coating as a barrier between steel and electrolyte (seawater) and the other is the cathodic protection(CP) supplying protection current. In the conventional design process of the cathodic protection system the required current densities of protected materials have been used. However, the anode position of field or laboratory experiment for obtaining the required current density for CP is significantly different from anode position for real structures. Therefore, the recent CP design must consider the optimum anode position for potential distribution equally over the ship hull. The CP design companies in the advanced countries can obtain the potential distribution results on the cathodic materials by using the computer analysis module. This study would show how to approach the potential analysis in the field of corrosion engineering. The computer program can predict the under protection area on the structure when the boundary condition and analysis procedure are reasonable. In this analysis the polarization curve is converted to the boundary condition in material data.

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Identification of pathways and genes associated with cerebral palsy

  • Zhu, Qingwen;Ni, Yufei;Wang, Jing;Yin, Honggang;Zhang, Qin;Zhang, Lingli;Bian, Wenjun;Liang, Bo;Kong, Lingyin;Xuan, Liming;Lu, Naru
    • Genes and Genomics
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    • 제40권12호
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    • pp.1339-1349
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    • 2018
  • Cerebral palsy (CP) is a non-progressive neurological disease, of which susceptibility is linked to genetic and environmental risk factors. More and more studies have shown that CP might be caused by multiple genetic factors, similar to other neurodevelopmental disorders. Due to the high genetic heterogeneity of CP, we focused on investigating related molecular pathways. Ten children with CP were collected for whole-exome sequencing by next-generation sequencing (NGS) technology. Customized processes were used to identify potential pathogenic pathways and variants. Three pathways (axon guidance, transmission across chemical synapses, protein-protein interactions at synapses) with twenty-three genes were identified to be highly correlated with CP. This study showed that the three pathways associated with CP might be the molecular mechanism of pathogenesis. These findings could provide useful clues for developing pathway-based pharmacotherapies. Further studies are required to confirm potential roles for these pathways in the pathogenesis of CP.

Effect of Cheongpyesagan-tang on LPS Induced Inflammation in RAW 264.7 Cells (LPS로 유도된 RAW 264.7 cell의 염증반응에서 청폐사간탕(淸肺瀉肝湯)의 항염증 효과)

  • Kim, Tae Yeon;Leem, Kang Hyun
    • Journal of Physiology & Pathology in Korean Medicine
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    • 제33권1호
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    • pp.31-38
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    • 2019
  • Cheongpyesagan-tang (CP) is one of the traditional medicinal prescription to treat Taeumin (太陰人)'s disease. It has been commonly used for the treatment of stroke, arthritis, diabetes and obesity. In this study, we investigated an anti-inflammatory potential of CP water extract. We examined the effects of CP on the lipopolysarccharide (LPS)-induced production of nitric oxide (NO) and prostaglandin $E_2$ ($PGE_2$). We also examined the levels of protein or mRNA of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) and proinflammatory cytokines in RAW 264.7 cells. CP inhibited NO and $PGE_2$ production in a dose dependent manner and decreased the protein and mRNA expression of iNOS and COX-2. Also, CP decreased the mRNA expression of interleukin-6 (IL-6), interleukin-$1{\beta}$ (IL-$1{\beta}$), tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$). These results suggest that CP has potential as anti-inflammatory therapeutic medicine.