Crevice Corrosion of Grade-2 Titanium in Saline Solutions at Different Temperatures and Oxygen Concentrations

2017 ◽  
Vol 164 (13) ◽  
pp. C788-C795 ◽  
Author(s):  
Thalia E. Standish ◽  
Mehdi Yari ◽  
David W. Shoesmith ◽  
James J. Noël
Keyword(s):  
Crevice Corrosion ◽  
Different Temperatures ◽  
Saline Solutions ◽  
Oxygen Concentrations

Localized Corrosion of UNS A95052 Aluminum Alloy for Application in Multi-Effect Desalinator Plants

CORROSION ◽  
10.5006/2815 ◽  
2018 ◽  
Vol 74 (9) ◽  
pp. 1023-1032
Author(s):  
Dannisa R. Chalfoun ◽  
Mariano A. Kappes ◽  
Mauricio Chocrón ◽  
Raul B. Rebak
Keyword(s):  
Aluminum Alloy ◽  
Crevice Corrosion ◽  
Low Cost ◽  
Localized Corrosion ◽  
Complete Evaluation ◽  
Electrochemical Tests ◽  
Metal Plates ◽  
Different Temperatures ◽  
Partially Occluded ◽  
Desalination Plants

Aluminum alloy UNS A95052 (AA5052) is very attractive for desalination applications because of its good corrosion resistance in seawater at temperatures up to 125°C, low cost, good thermal conductivity, and non-toxicity of its corrosion products. The pitting corrosion potential, Epit, and the pit repassivation potential, Er,pit, of AA5052 were measured in deaerated 65,000 ppm sodium chloride (NaCl) solutions at 30°C, 60°C, and 85°C. Epit decreased with temperature, in accord with literature results. Er,pit was a function of anodic charge passed during pit growth stage. A complete evaluation of suitability of this alloy from a corrosion perspective requires also studies of crevice corrosion at different temperatures, considering that multi-plate designs of desalinators have metal plates in contact with rubber gaskets and seals. Cyclic potentiodynamic polarization was used to estimate crevice repassivation potentials, Er,crev, at 30°C, 60°C, and 85°C, in specimens with an attached rubber O-ring as a crevice former. This crevice former simulated the partially occluded geometry expected in desalination plants. Stable crevice corrosion potentials, Ecrev, were similar to Epit, and, when polarized to a similar anodic charge density, Er,crev were similar to Er,pit. Based on this result, from a corrosion perspective, the presence of crevices in the desalination plant is not expected to present an additional risk during operation of the plant. Electrochemical tests were also performed in saturated AlCl3 solutions to explain the results using Galvele’s localized acidification model.

The self-sustaining propagation of crevice corrosion on the hybrid BC1 Ni–Cr–Mo alloy in hot saline solutions

2016 ◽  
Vol 105 ◽  
pp. 58-67 ◽  
Author(s):  
N. Ebrahimi ◽  
J.J. Noël ◽  
M.A. Rodríguez ◽  
D.W. Shoesmith
Keyword(s):  
Crevice Corrosion ◽  
The Self ◽  
Saline Solutions

Factors determining the in vitro emergence of sexual stages of Hepatozoon clamatae from erythrocytes of the Green Frog (Rana clamitans)

2013 ◽  
Vol 91 (4) ◽  
pp. 219-226 ◽  
Author(s):  
M.J. Trites ◽  
L.V. Ferguson ◽  
C.T. Ogbuah ◽  
C.M. Dickson ◽  
T.G. Smith
Keyword(s):  
Xanthurenic Acid ◽  
Rana Clamitans ◽  
Apicomplexan Parasites ◽  
Parasite Plasmodium ◽  
Parasite Plasmodium Falciparum ◽  
Different Temperatures ◽  
Sexual Stages ◽  
Incubation Temperatures ◽  
Saline Solutions

Sexual reproduction of apicomplexan parasites in haematophagous arthropods requires that intracellular sexual stages of these protozoa escape vertebrate erythrocytes in the blood meal. Although cues that signal sexual stages of the human malaria parasite (Plasmodium falciparum Welch, 1897) to emerge from erythrocytes are well documented, such signals are poorly known for other blood-dwelling Apicomplexa. The objective of this comparative study was to investigate conditions required to induce in vitro emergence of sexual stages of Hepatozoon clamatae (Stebbins, 1905) from frog erythrocytes. Blood was drawn from Green Frogs (Rana clamitans Latreille in Sonnini de Manoncourt and Latreille, 1801 = Lithobates clamitans clamitans (Latreille in Sonnini de Manoncourt and Latreille, 1801)) infected with H. clamatae and treated with solutions of various concentrations of saline, pH, and xanthurenic acid at different temperatures. Hypertonic saline solutions of 200 and 222 mmol/L at pH 7.4 and 7.7 elicited emergence of nearly 100% of gamonts from frog erythrocytes, but at pH 8.0 resulted in decreased emergence. Solutions containing 1, 10, and 100 μmol/L xanthurenic acid increased gamont emergence at saline concentrations of 156, 178, and 244 mmol/L, but decreased emergence at 200 and 222 mmol/L. Gamont emergence increased as incubation temperatures increased from 18 to 26 °C. These results suggest that conditions necessary for emergence of sexual stages of bloodstream Apicomplexa from erythrocytes vary among genera.

scholarly journals Controlling suction by the vapour equilibrium technique at different temperatures and its application in determining the water retention properties of MX80 clay

2005 ◽  
Vol 42 (1) ◽  
pp. 287-296 ◽  
Author(s):  
Anh-Minh Tang ◽  
Yu-Jun Cui
Keyword(s):  
Thermal Effects ◽  
Unsaturated Soils ◽  
Water Retention ◽  
Water Retention Curve ◽  
Retention Curve ◽  
Temperature Changes ◽  
Different Temperatures ◽  
Water Retention Properties ◽  
Saline Solutions ◽  
Good Agreement

Problems related to unsaturated soils are frequently encountered in geotechnical or environmental engineering works. In most cases, for simplicity, one can study the problems by considering the suction effects on volume change or shear strength under isothermal conditions. Often, under these conditions, a temperature-independent water retention curve is considered in the analysis — obviously a simplification. When the temperature changes are too significant to be ignored, it is necessary to account for the thermal effects. This note presents a method for controlling suction with the vapour equilibrium technique at different temperatures. First, calibration of various saturated saline solutions was carried out at temperatures ranging from 20 °C to 60 °C. A mirror psychrometer was used to measure relative humidity generated by saturated saline solutions at different temperatures. The results obtained were in good agreement with the data from the literature. This information was then used to determine the water retention properties of MX80 clay, which showed that the retention curve shifts downward with increasing temperature.Key words: vapour equilibrium technique, hygrometer, water retention curve, temperature effects, compacted bentonite.

scholarly journals Determination of the water sorption isotherms for cassava flour

2010 ◽  
Vol 1 (2) ◽  
pp. 83 ◽  
Author(s):  
Juliana Fermino Farias ◽  
Mirele Fernandes Ferreira ◽  
Wagner André dos Santos ◽  
Evandro Bona
Keyword(s):  
Water Sorption ◽  
Chemical Properties ◽  
Sorption Isotherms ◽  
Small Variation ◽  
Cassava Flour ◽  
Different Temperatures ◽  
Saline Solutions ◽  
Processing Steps ◽  
Water Sorption Isotherms

<p>Cassava is a nourishing food and widely consumed in Brazil in the form of flour. However, it is necessary a more detailed study of the physical-chemical properties of the cassava flour and thus optimize its processing steps such as drying. The objective of this work was to obtain the water sorption isotherms for the cassava flour at different temperatures. For this aim, experiments were carried out using the static method with saturated saline solutions at 30, 40, 60 and 70&deg;C. The data obtained were adjusted on available literature equations using the software MATLAB R2007b. The results indicate that the temperature ranging from 40 to 70&deg;C does not significantly influence the cassava flour equilibrium moisture. It was also found &nbsp;that both Halsey and Smith's isotherm can be used to predict the cassava flour equilibrium moisture. Furthermore, it was observed a small variation in the equilibrium moisture for water activity ranging from 0 to 0.8.</p><p>&nbsp;</p><p>DOI: http://dx.doi.org/10.14685/rebrapa.v1i2.21</p>

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