In Situ Monitoring of the Microstructural Corrosion Mechanisms of Zinc-Magnesium-Aluminum Alloys Using Time Lapse Microscopy and ICP-MS Ionic Analysis

2010 ◽  
Keyword(s):  
Aluminum Alloys ◽  
Time Lapse ◽  
In Situ Monitoring ◽  
Time Lapse Microscopy ◽  
Icp Ms ◽  
Corrosion Mechanisms

scholarly journals In situ monitoring of corrosion mechanisms and phosphate inhibitor surface deposition during corrosion of zinc–magnesium–aluminium (ZMA) alloys using novel time-lapse microscopy

2015 ◽  
Vol 180 ◽  
pp. 361-379 ◽  
Author(s):  
James Sullivan ◽  
Nathan Cooze ◽  
Callum Gallagher ◽  
Tom Lewis ◽  
Tomas Prosek ◽  
...  
Keyword(s):  
Image Analysis ◽  
Mass Loss ◽  
Alloy System ◽  
Time Lapse ◽  
Open Circuit ◽  
In Situ Monitoring ◽  
Corrosion Mechanism ◽  
Saturation Effects ◽  
Corrosion Mechanisms

In situtime-lapse optical microscopy was used to examine the microstructural corrosion mechanisms in three zinc–magnesium–aluminium (ZMA) alloy coated steels immersed in 1% NaCl pH 7. Preferential corrosion of MgZn2lamellae within the eutectic phases was observed in all the ZMA alloys followed by subsequent dissolution of Zn rich phases. The total extent and rate of corrosion, measured using time-lapse image analysis and scanning vibrating electrode technique (SVET) estimated mass loss, decreased as Mg and Al alloying additions were increased up to a level of 3 wt% Mg and 3.7 wt% Al. This was probably due to the increased presence of MgO and Al2O3at the alloy surface retarding the kinetics of cathodic oxygen reduction. The addition of 1 × 10−2mol dm−3Na3PO4to 1% NaCl pH 7 had a dramatic influence on the corrosion mechanism for a ZMA with passivation of anodic sites through phosphate precipitation observed using time-lapse image analysis. Intriguing rapid precipitation of filamentous phosphate was also observed and it is postulated that these filaments nucleate and grow due to super saturation effects. Polarisation experiments showed that the addition of 1 × 10−2mol dm−3Na3PO4to the 1% NaCl electrolyte promoted an anodic shift of 50 mV in open circuit potential for the ZMA alloy with a reduction in anodic current of 2.5 orders of magnitude suggesting that it was acting primarily as an anodic inhibitor supporting the inferences from the time-lapse investigations. These phosphate additions resulted in a 98% reduction in estimated mass loss as measured by SVET demonstrating the effectiveness of phosphate inhibitors for this alloy system.

scholarly journals Accurate dating of stalagmites from low seasonal contrast tropical Pacific climate using Sr 2D maps, fabrics and annual hydrological cycles

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mohammadali Faraji ◽  
Andrea Borsato ◽  
Silvia Frisia ◽  
John C. Hellstrom ◽  
Andrew Lorrey ◽  
...  
Keyword(s):  
Principal Component ◽  
Tropical Pacific ◽  
In Situ Monitoring ◽  
Marine Aerosols ◽  
Icp Ms ◽  
Optical Maps ◽  
Hydrological Cycles ◽  
Climate Proxies ◽  
Dimensional Mapping

AbstractTropical Pacific stalagmites are commonly affected by dating uncertainties because of their low U concentration and/or elevated initial 230Th content. This poses problems in establishing reliable trends and periodicities for droughts and pluvial episodes in a region vulnerable to climate change. Here we constrain the chronology of a Cook Islands stalagmite using synchrotron µXRF two-dimensional mapping of Sr concentrations coupled with growth laminae optical imaging constrained by in situ monitoring. Unidimensional LA-ICP-MS-generated Mg, Sr, Ba and Na variability series were anchored to the 2D Sr and optical maps. The annual hydrological significance of Mg, Sr, Ba and Na was tested by principal component analysis, which revealed that Mg and Na are related to dry-season, wind-transported marine aerosols, similar to the host-rock derived Sr and Ba signatures. Trace element annual banding was then used to generate a calendar-year master chronology with a dating uncertainty maximum of ± 15 years over 336 years. Our approach demonstrates that accurate chronologies and coupled hydroclimate proxies can be obtained from speleothems formed in tropical settings where low seasonality and problematic U–Th dating would discourage the use of high-resolution climate proxies datasets.

In situ monitoring of single molecule binding reactions with time-lapse atomic force microscopy on functionalized DNA origami

Nanoscale ◽  
2011 ◽  
Vol 3 (6) ◽  
pp. 2481 ◽  
Author(s):  
Na Wu ◽  
Xingfei Zhou ◽  
Daniel M. Czajkowsky ◽  
Ming Ye ◽  
Dongdong Zeng ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Single Molecule ◽  
Time Lapse ◽  
Dna Origami ◽  
In Situ Monitoring ◽  
Force Microscopy ◽  
Atomic Force

scholarly journals Respirometric in Situ Methods for Real-Time Monitoring of Corrosion Rates: Part II. Immersion

2020 ◽  
Author(s):  
Michael Strebl ◽  
Mark Bruns ◽  
Ghina Schulze ◽  
Sannakaisa Virtanen
Keyword(s):  
Real Time ◽  
In Situ Monitoring ◽  
Intermittent Flow ◽  
Real Time Monitoring ◽  
Corrosion Rates ◽  
Immersion Corrosion ◽  
In Situ Methods ◽  
Flow Through ◽  
Corrosion Mechanisms

With the aim to open a new window into corrosion processes this paper presents respirometric methods for real-time in situ monitoring of corrosion rates under immersion conditions. With these techniques, sensitive, non-destructive corrosion rate measurements are possible on basically all metals and alloys. Different methods are presented that enable to monitor HER, ORR or both reactions simultaneously based on the amount of evolved H2 or the amount of consumed O2 by volumetric, manometric and sensor-based approaches. Various research examples are presented, demonstrating the benefits and limitations of the different approaches. For Mg alloys, besides HER, ORR plays a role in the cathodic reactions and a good correlation of the total cathodic charge with mass loss was obtained. H2 dissolution into the electrolyte was identified as an important factor. The results obtained for Zn immersion corrosion in intermittent-flow and flow-through respirometric experiments suggest that the ORR mechanism leads to the generation of stable H2O2 under these conditions. As a result, the effective number of exchanged electrons for one O2 molecule was found to be in between two and four. The here introduced respirometric techniques allow new insights into corrosion mechanisms, in addition to enabling real-time monitoring of corrosion.

Experience of using time-lapse microscopy in IVF and ICSI programs

2020 ◽  
pp. 47-50
Author(s):  
N. V. Saraeva ◽  
N. V. Spiridonova ◽  
M. T. Tugushev ◽  
O. V. Shurygina ◽  
A. I. Sinitsyna
Keyword(s):  
Pregnancy Rate ◽  
Embryo Transfer ◽  
Selection Procedure ◽  
Time Lapse ◽  
Single Embryo Transfer ◽  
Main Group ◽  
Clinical Pregnancy ◽  
Control Group ◽  
Time Lapse Microscopy

In order to increase the pregnancy rate in the assisted reproductive technology, the selection of one embryo with the highest implantation potential it is very important. Time-lapse microscopy (TLM) is a tool for selecting quality embryos for transfer. This study aimed to assess the benefits of single-embryo transfer of autologous oocytes performed on day 5 of embryo incubation in a TLM-equipped system in IVF and ICSI programs. Single-embryo transfer following incubation in a TLM-equipped incubator was performed in 282 patients, who formed the main group; the control group consisted of 461 patients undergoing single-embryo transfer following a traditional culture and embryo selection procedure. We assessed the quality of transferred embryos, the rates of clinical pregnancy and delivery. The groups did not differ in the ratio of IVF and ICSI cycles, average age, and infertility factor. The proportion of excellent quality embryos for transfer was 77.0% in the main group and 65.1% in the control group (p = 0.001). In the subgroup with receiving eight and less oocytes we noted the tendency of receiving more quality embryos in the main group (р = 0.052). In the subgroup of nine and more oocytes the quality of the transferred embryos did not differ between two groups. The clinical pregnancy rate was 60.2% in the main group and 52.9% in the control group (p = 0.057). The delivery rate was 45.0% in the main group and 39.9% in the control group (p > 0.050).

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