Corrosion Behaviors of B10 under the Combination Action of Sulfate-Reducing Bacteria and V.Natriegens

2011 ◽  
Vol 343-344 ◽  
pp. 101-105
Author(s):  
Cai Xiang Gu ◽  
Xing Hua Du ◽  
Wei Li ◽  
Guan Jun Zhu

Polarization curves, corrosion potential, scanning electron microscopy (SEM) were adopted in order to investigate the corrosion behaviors of B10 under the combination action of anaerobic SRB and facultative anaerobic V.natriegens. The characteristics and mechanisms of microbial corrosion action in sea water were analyzed in this paper. The results show that the existence of marine microorganisms accelerates the corrosion process of B10; SRB in the mixed microbe medium plays a leading role; the combined action of SRB and V.natriegens influences the matrix surface reunion phenomenon seriously and prone to pitting corrosion. Furthermore, this investigation indicates that the affectability of microbial corrosion of the base metal can be shown as follows: SRB > Mixed bacteria > V.natriegens > Sterile.

2011 ◽  
Vol 356-360 ◽  
pp. 161-164
Author(s):  
Cai Xiang Gu ◽  
Xiao Ming Zhao ◽  
Yan Sheng Yin ◽  
Gui Jun Ji

Advantage strains SRB and V.natriegens were obtained from the China East Sea for this study. Polarization curves, corrosion potential, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) analyses were adopted in order to investigate the corrosion behaviors of 0Cr18Ni9 stainless steel under the combination action of anaerobic SRB and facultative anaerobic V.natriegens, The characteristics and mechanisms of microbial corrosion action in sea water were analyzed in this paper. The results show that SRB and V.natriegens promote each other’s growth when cultivated in the mixed microbe medium, in which the rate of corrosion is higher than that in the single microbe; Under the combined action of the mixed microbe, the microbial film gets wider and thicker, and corrosion products and metabolite are produced, which furthermore accelerates the passivation and pit corrosion to the 0Cr18Ni9 stainless steel.


2015 ◽  
Vol 1119 ◽  
pp. 365-369
Author(s):  
G. Purushotham ◽  
Joel Hemanth

Nickel alloys have wide-spread applications in mechanical, tribological and corrosion components such as clutches, cylinder liners, pistons in the automotive industry and marine components in sea water owing to its relative corrosion resistant & good thermal conductivity. The presence of silicon results in reduction of the co-efficient of thermal expansion of nickel & produces an alloy with good casting machining & corrosion characteristics. Further it is reported that addition of silica, improves the mechanical properties which in turn has profound influence on the mechanical properties and corrosion behavior of Nickel-SiO2 alloys. Therefore an investigation in the present research will be made to fabricate and evaluate the microstructure, corrosion of chilled composites consisting of nickel matrix and fused SiO2 particles as the reinforcement (size 40-150 µm) in the matrix. The reinforcement being added ranges from 3 to 12 wt. % in steps of 3%. The resulting composites cast in moulds containing metallic and non metallic chill block (MS, SiC & Cu) were tested for their microstructure and corrosion behaviors. The main objective of the present research is to obtain fine grain Ni/SiO2 chilled sound composite having very good mechanical and corrosion properties.


2011 ◽  
Vol 335-336 ◽  
pp. 752-755
Author(s):  
Cai Xiang Gu ◽  
Xing Hua Du ◽  
Guan Jun Zhu ◽  
Yan Sheng Yin ◽  
Wen Ge Li

Polarization curves, corrosion potential, scanning electron microscopy (SEM) were adopted to investigate the corrosion behaviors of QSn4-3 under two kinds of marine advantage bacteria (anaerobic SRB and facultative anaerobic Vibrio natriegens) environment. The results show that the microbial film has some effects on inhibiting corrosion of QSn4-3 at the early stage of corrosion; the existence of marine microorganisms accelerates the corrosion process of QSn4-3; the combined action of SRB and V.natriegens accelerates the corrosion obviously and QSn4-3 coupon is more prone to pitting corrosion.


3 Biotech ◽  
2018 ◽  
Vol 8 (12) ◽  
Author(s):  
Shanthi Vaithiyanathan ◽  
Karthikeyan Chandrasekaran ◽  
R. C. Barik

2016 ◽  
Vol 04 (01) ◽  
pp. 1640001 ◽  
Author(s):  
Ying Wan ◽  
Xing Li ◽  
Shenqi Wang

Biohybrid materials play an important role in tissue engineering, artificial organs and regenerative medicine due to their regulation of cell function through specific cell–matrix interactions involving integrins, mostly those of fibroblasts and myofibroblasts, and ligands on the matrix surface, which have become current research focus. In this paper, recent progress of biohybrid materials, mainly including main types of biohybrid materials, rapid prototype (RP) technique for construction of 3D biohybrid materials, was reviewed in detail; moreover, their applications in tissue engineering, artificial organs and regenerative medicine were also reviewed in detail. At last, we address the challenges biohybrid materials may face.


2009 ◽  
Vol 79-82 ◽  
pp. 1017-1020 ◽  
Author(s):  
Hui Shu Zhang ◽  
Dong Ping Zhan ◽  
Song Lian Bai ◽  
Zhou Hua Jiang

The corrosion behaviors of Al-Si-Cr-Cu bearing low carbon steel and a reference steel Q235 were tested in a cyclic dry/wet environment containing 0.01mol/L NaHSO3 in laboratory. Rust layers were observed by optical microscope (OM), scanning electron microscopy (SEM) and XRD. The electrochemical behaviors of the steels were studied on the polarization curves and electrochemical impedance spectroscopy (EIS). The results indicate that after 120h corrosion test, the annual corrosion rates of the designed steels reduce 42 % than Q235 at least. The corrosion products are generally iron oxyhydroxides and oxides such as FeOOH, γ-FeOOH, α-FeOOH, γ-Fe2O3, Fe3O4. The α-FeOOH possesses good stabilization mainly exits and can improve the corrosion resistance. There are the enrichments of Cu, Cr, Si and Al in the rust layer close to the matrix, which make the rust layer be more compact and protected. The corrosion currents of the two designed steels are lower than that of Q235, the corrosion potentials are higher than that of Q235 after Tafel fitting. The rust layer impedances of the designed steels are higher than that of Q235.


2007 ◽  
Vol 189 (24) ◽  
pp. 8901-8913 ◽  
Author(s):  
Antje Labes ◽  
Peter Schönheit

ABSTRACT The hyperthermophilic archaeon Archaeoglobus fulgidus strain 7324 has been shown to grow on starch and sulfate and thus represents the first sulfate reducer able to degrade polymeric sugars. The enzymes involved in starch degradation to glucose 6-phosphate were studied. In extracts of starch-grown cells the activities of the classical starch degradation enzymes, α-amylase and amylopullulanase, could not be detected. Instead, evidence is presented here that A. fulgidus utilizes an unusual pathway of starch degradation involving cyclodextrins as intermediates. The pathway comprises the combined action of an extracellular cyclodextrin glucanotransferase (CGTase) converting starch to cyclodextrins and the intracellular conversion of cyclodextrins to glucose 6-phosphate via cyclodextrinase (CDase), maltodextrin phosphorylase (Mal-P), and phosphoglucomutase (PGM). These enzymes, which are all induced after growth on starch, were characterized. CGTase catalyzed the conversion of starch to mainly β-cyclodextrin. The gene encoding CGTase was cloned and sequenced and showed highest similarity to a glucanotransferase from Thermococcus litoralis. After transport of the cyclodextrins into the cell by a transport system to be defined, these molecules are linearized via a CDase, catalyzing exclusively the ring opening of the cyclodextrins to the respective maltooligodextrins. These are degraded by a Mal-P to glucose 1-phosphate. Finally, PGM catalyzes the conversion of glucose 1-phosphate to glucose 6-phosphate, which is further degraded to pyruvate via the modified Embden-Meyerhof pathway.


2013 ◽  
Vol 393 ◽  
pp. 919-924
Author(s):  
Muhd Azimin Ab Ghani ◽  
A.F. Ahmad Kamal ◽  
Mohamad Ali Ahmad ◽  
Y.M.D. Taib ◽  
Z. Salleh ◽  
...  

This paper presents an experimental study on the influence of fiberglass woven in Long Kenaf Polyester Composite (LKPC). Wear and friction characteristics were examined using sea water and sand as a slurry. Wear test were carried out using Slurry Erosion Test Rig (TR-40). These tests were performed at room temperature with speed of 200 rpm for every 2 km interval. The results from the tests show that mass loss were depends on the matrix composition of the composite. Surface Roughness, Ra, was consistently reduced after each test in all cases.


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