Micro-Raman investigations of early stage silver corrosion products occurring in sulfur containing atmospheres

2013 ◽  
Vol 44 (5) ◽  
pp. 770-775 ◽  
Author(s):  
I. Martina ◽  
R. Wiesinger ◽  
M. Schreiner
Keyword(s):  
Early Stage ◽  
Corrosion Products ◽  
Sulfur Containing

scholarly journals Biosynthesis of Sulfur-Containing Small Biomolecules in Plants

2020 ◽  
Vol 21 (10) ◽  
pp. 3470 ◽  
Author(s):  
Yumi Nakai ◽  
Akiko Maruyama-Nakashita
Keyword(s):  
Redox Regulation ◽  
Early Stage ◽  
Plant Cells ◽  
Essential Element ◽  
Thiol Group ◽  
Sulfur Transfer ◽  
Transfer Processes ◽  
Characteristic Features ◽  
Small Biomolecules ◽  
Sulfur Containing

Sulfur is an essential element required for plant growth. It can be found as a thiol group of proteins or non-protein molecules, and as various sulfur-containing small biomolecules, including iron-sulfur (Fe/S) clusters, molybdenum cofactor (Moco), and sulfur-modified nucleotides. Thiol-mediated redox regulation has been well investigated, whereas biosynthesis pathways of the sulfur-containing small biomolecules have not yet been clearly described. In order to understand overall sulfur transfer processes in plant cells, it is important to elucidate the relationships among various sulfur delivery pathways as well as to investigate their interactions. In this review, we summarize the information from recent studies on the biosynthesis pathways of several sulfur-containing small biomolecules and the proteins participating in these processes. In addition, we show characteristic features of gene expression in Arabidopsis at the early stage of sulfate depletion from the medium, and we provide insights into sulfur transfer processes in plant cells.

scholarly journals Corrosion behavior of double-glow plasma copperizing coating on Q235 steel

2020 ◽  
Vol 56 (2) ◽  
pp. 257-268
Author(s):  
Z.-G. Yang ◽  
W.-P. Liang ◽  
Y.-L. Jia ◽  
Q. Miao ◽  
Z. Ding ◽  
...  
Keyword(s):  
Copper Ions ◽  
Early Stage ◽  
Iron Hydroxide ◽  
Electrochemical Measurement ◽  
Charge Transfer Resistance ◽  
Corrosion Products ◽  
Thermodynamical Equilibrium ◽  
Transfer Resistance ◽  
Q235 Steel ◽  
Glow Plasma

In this paper, the copperized layerwas fabricated on the surface of Q235 steel via double glow plasma surface alloying technology to improve the marine fouling organisms attached on the surface of marine structures. The microstructure and phases composition of the coating were analyzed by SEM and XRD. The corrosion characteristics of substrate and coating were investigated in 3.5wt.% NaCl solution.The results indicated that the protective coating had a novel structure of an outermost deposition layer (85?m) and inner diffusion layer (51 ?m), which exhibited great adhesion stress because of the metallurgical bonding effects. The corrosion characteristics of substrate and coating were analyzed in detail. The corrosion products of Q235 steel were mainly ?-FeOOH, ?-FeOOH, and ?-FeOOH in the early stage of corrosion process. Then the whisker-like structure of ?-FeOOH grew on the surface of ?-FeOOH and the ?-FeOOH transformed into ?-FeOOH to achieve thermodynamical equilibrium. The dissolved copper ions in solution resulted in a unique difference in the formation of corrosion products, which inhibited the transition of iron hydroxide and promoted the formation of amorphous phases. Based on electrochemical measurement, the coating hadlower corrosion current density and higher charge transfer resistance than substrate. The corrosion resistance of copperized layer wasbetter than that of Q235 steel.

scholarly journals Corrosion Behavior of Corrosion-Resistant Spring Steel Used in High Speed Railway

2021 ◽  
Vol 11 (18) ◽  
pp. 8668
Author(s):  
Jinbo Li ◽  
Ziying Zhu ◽  
Hongwei Chen ◽  
Shaojie Li ◽  
Hongyan Wu ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
High Speed ◽  
Corrosion Potential ◽  
Early Stage ◽  
Corrosion Current ◽  
Corrosion Products ◽  
Atmospheric Environment ◽  
Rust Layer ◽  
Experimental Steel

Corrosion behavior of 60Si2Mn-A and 60Si2Mn-B in simulated industrial atmospheric environment was investigated by alternate immersion corrosion test and electrochemical method. The phase, morphology, characteristics of corrosion products, and the distribution of Cr, Cu, and Ni in the corrosion products of experimental steel were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), and electron probe microanalyzer (EPMA). The results show that the phase of rust layer is Fe3O4 and γ-FeOOH in the early stage and then changes to α-FeOOH and γ-FeOOH in the later stage; the size of the rust layer with corrosion resistance of 60Si2Mn is less than 60Si2Mn; the Cr element accumulates in the rust layer of the experimental steel in the early stage of corrosion resistance; and Cu, Ni, and Cr in the corrosion resistance 60Si2Mn are concentrated in the rust layer near the substrate In the later stage of corrosion. As the corrosion cycle is prolonged, the corrosion potential and the resistance of the rust layer of the experimental steel increases, and the corrosion current decreases; in the same corrosion cycle, the corrosion potential and corrosion resistance of 60Si2Mn-B are greater than 60Si2Mn, and the corrosion current is less than 60Si2Mn.

scholarly journals Early Stage of Corrosion Formation on Pipeline Steel X70 Under Oxyfuel Atmosphere at Low Temperature

Processes ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 421
Author(s):  
Andreas Kratzig ◽  
Le Quynh Hoa ◽  
Dirk Bettge ◽  
Martina Menneken ◽  
Ralph Bäßler
Keyword(s):  
Raman Spectroscopy ◽  
Pipeline Steel ◽  
Early Stage ◽  
Ambient Pressure ◽  
Corrosion Layer ◽  
Corrosion Products ◽  
X Ray ◽  
Pit Formation ◽  
Additional Water

The early stage of corrosion formation on X70 pipeline steel under oxyfuel atmosphere was investigated by applying a simulated gas mixture (CO2 containing 6700 ppmv O2, 100 ppmv NO2, 70 ppmv SO2 and 50 ppmv H2O) for 15 h at 278 K and ambient pressure. Short-term tests (6 h) revealed that the corrosion starts as local spots related to grinding marks progressing by time and moisture until a closed layer was formed. Acid droplets (pH 1.5), generated in the gas atmosphere, containing a mixture of H2SO4 and HNO3, were identified as corrosion starters. After 15 h of exposure, corrosion products were mainly X-ray amorphous and only partially crystalline. In-situ energy-dispersive X-ray diffraction (EDXRD) results showed that the crystalline fractions consist primarily of water-bearing iron sulfates. Applying Raman spectroscopy, water-bearing iron nitrates were detected as subordinated phases. Supplementary long-term tests exhibited a significant increase in the crystalline fraction and formation of additional water-bearing iron sulfates. All phases of the corrosion layer were intergrown in a nanocrystalline network. In addition, numerous globular structures have been detected above the corrosion layer, which were identified as hydrated iron sulphate and hematite. As a type of corrosion, shallow pit formation was identified, and the corrosion rate was about 0.1 mma−1. In addition to in-situ EDXRD, SEM/EDS, TEM, Raman spectroscopy and interferometry were used to chemically and microstructurally analyze the corrosion products.

Characterization of Bronze Corrosion Products on Exposition to Sulphur Dioxide

2010 ◽  
Vol 138 ◽  
pp. 21-28 ◽  
Author(s):  
B. De Filippo ◽  
L. Campanella ◽  
A. Brotzu ◽  
S. Natali ◽  
D. Ferro
Keyword(s):  
Sulfur Dioxide ◽  
Relative Humidity ◽  
Early Stage ◽  
Xrd Analysis ◽  
Corrosion Products ◽  
X Ray Diffraction ◽  
X Ray ◽  
Weight Variation ◽  
Room Condition

In the main frame of the research aimed to model the corrosion growth on bronze surface, the objective of the work here reported has been to characterize the corrosion products formed on laboratory samples of bronze alloy (Cu Sn12), during the early stage of exposure to moist air with sulfur dioxide. A cycling corrosion cabinet was used to control 200 ppm gas concentration, relative humidity (RH) and temperature, according to the DIN 50018 (Kesternich test).The method is designed to evaluate how well the surface resists to sulfur dioxide corrosion; the test cycle consists of 8 hours exposure to sulfur dioxide at 40°C temperature and 100% relative humidity, followed by 12 hours drying at room condition. Weight variation, Spectrophotometer, Scanning Electron Microscopy with X-ray microanalysis (SEM-EDS), X-ray Diffraction (XRD) analysis were carried out for the tarnish products characterization. Some of the compound identified were brochantite (Cu4(OH)6SO4), chalcanthite (CuSO4•5H2O) cuprite (Cu2O), cassiterite (SnO2) and ottemannite (Sn2O3).

Methionine-Specific Staining of Collagen

1982 ◽  
Vol 40 ◽  
pp. 294-295
Author(s):  
E.M. Kuhn ◽  
K.D. Marenus ◽  
M. Beer
Keyword(s):  
Amino Acids ◽  
Collagen Fibers ◽  
Type Iii Collagen ◽  
Type I ◽  
Electron Microscopic ◽  
Good Correspondence ◽  
Specific Staining ◽  
Type Iii ◽  
Different Types ◽  
Sulfur Containing

Fibers composed of different types of collagen cannot be differentiated by conventional electron microscopic stains. We are developing staining procedures aimed at identifying collagen fibers of different types.Pt(Gly-L-Met)Cl binds specifically to sulfur-containing amino acids. Different collagens have methionine (met) residues at somewhat different positions. A good correspondence has been reported between known met positions and Pt(GLM) bands in rat Type I SLS (collagen aggregates in which molecules lie adjacent to each other in exact register). We have confirmed this relationship in Type III collagen SLS (Fig. 1).

Alterations in the number of motoneurons containing immunoreactive calcitonin gene-related peptide(CGRP)& choline acetyltransferase(ChAT) in the cervical spinal cord of the wobbler mouse during the development of the motoneuron disease

1995 ◽  
Vol 53 ◽  
pp. 970-971
Author(s):  
L. Vacca-Galloway ◽  
Y.Q. Zhang ◽  
P. Bose ◽  
S.H. Zhang
Keyword(s):  
Spinal Cord ◽  
Early Stage ◽  
Cervical Spinal Cord ◽  
Wild Type Mouse ◽  
Reflex Response ◽  
Mouse Strains ◽  
Behavioral Tests ◽  
Wobbler Mouse ◽  
Stage 4 ◽  
Stage 1

The Wobbler mouse (wr) has been studied as a model for inherited human motoneuron diseases (MNDs). Using behavioral tests for forelimb power, walking, climbing, and the “clasp-like reflex” response, the progress of the MND can be categorized into early (Stage 1, age 21 days) and late (Stage 4, age 3 months) stages. Age-and sex-matched normal phenotype littermates (NFR/wr) were used as controls (Stage 0), as well as mice from two related wild-type mouse strains: NFR/N and a C57BI/6N. Using behavioral tests, we also detected pre-symptomatic Wobblers at postnatal ages 7 and 14 days. The mice were anesthetized and perfusion-fixed for immunocytochemical (ICC) of CGRP and ChAT in the spinal cord (C3 to C5).Using computerized morphomety (Vidas, Zeiss), the numbers of IR-CGRP labelled motoneurons were significantly lower in 14 day old Wobbler specimens compared with the controls (Fig. 1). The same trend was observed at 21 days (Stage 1) and 3 months (Stage 4). The IR-CGRP-containing motoneurons in the Wobbler specimens declined progressively with age.

Automated high-resolution microscopy: the approaches so far

1987 ◽  
Vol 45 ◽  
pp. 58-61
Author(s):  
W. O. Saxton
Keyword(s):  
High Resolution ◽  
Early Stage ◽  
Automatic Recording ◽  
Microprocessor Control ◽  
Alternative Systems ◽  
Electron Image ◽  
Complete Automation ◽  
Analysis System ◽  
High Resolution Microscopy

Recent commercial microscopes with internal microprocessor control of all major functions have already demonstrated some of the benefits anticipated from such systems, such as continuous magnification, rotation-free diffraction and magnification, automatic recording of mutually registered focal series, and fewer control knobs. Complete automation of the focusing, stigmating and alignment of a high resolution microscope, allowing focal series to be recorded at preselected focus values as well, is still imminent rather than accomplished, however; some kind of image pick-up and analysis system, fed with the electron image via a TV camera, is clearly essential for this, but several alternative systems and algorithms are still being explored. This paper reviews the options critically in turn, and stresses the need to consider alignment and focusing at an early stage, and not merely as an optional extension to a basic proposal.

Direct observation of Fe-Al-Zn ternary intermetallic compound and its transformation during the early stage of hot-dip galvanizing

1993 ◽  
Vol 51 ◽  
pp. 1116-1117
Author(s):  
C. S. Lin ◽  
W. A. Chiou ◽  
M. Meshii
Keyword(s):  
Intermetallic Compound ◽  
Reaction Rate ◽  
Diffusion Rate ◽  
Early Stage ◽  
Zinc Bath ◽  
Steel Sheets ◽  
Direct Observations ◽  
Solid Iron ◽  
Iron And Zinc ◽  
Ternary Intermetallic Compound

The galvannealed steel sheets have received ever increased attention because of their excellent post-painting corrosion resistance and good weldability. However, its powdering and flaking tendency during press forming processes strongly impairs its performance. In order to optimize the properties of galvanneal coatings, it is critical to control the reaction rate between solid iron and molten zinc.In commercial galvannealing line, aluminum is added to zinc bath to retard the diffusion rate between iron and zinc by the formation of a thin layer of Al intermetallic compound on the surface of steel at initial hot-dip galvanizing. However, the form of this compound and its transformation are still speculated. In this paper, we report the direct observations of this compound and its transformation.The specimens were prepared in a hot-dip simulator in which the steel was galvanized in the zinc bath containing 0.14 wt% of Al at a temperature of 480 °C for 5 seconds and was quenched by liquid nitrogen.

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