Corrosion of Ti99.8-Pd Under Gamma Irradiation in MgC12-Rich Brine

1997 ◽  
Vol 506 ◽  
Author(s):  
E. Smailos ◽  
D. Schild ◽  
K. Gompper
Keyword(s):  
Surface Layer ◽  
Field Experiments ◽  
Surface Films ◽  
General Corrosion ◽  
Experimental Conditions ◽  
Test Conditions ◽  
Strong Candidate ◽  
Main Component ◽  
Container Material

ABSTRACTThe combined influence of gamma radiation (10 Gy/h) and high temperature (150 °C) on the corrosion of the promising HLW container material Ti99.8-Pd was investigated in an MgCl2-rich brine, and the corrosion surface films formed were characterized by XPS. For comparison, specimens without irradiation were also examined.Under the test conditions used, the alloy Ti99.8-Pd is resistant to local corrosion and its general corrosion is negligible low. The thin corrosion films formed on the surface of unirradiated specimens and in the crevices of specimens exposed to radiation consist of TiO2. However, outside the crevices of irradiated specimens, a surface layer consisting of Mg (main component of the brine) and Si (impurity in the brine) oxide is built up over the TiO2 layer. Comparable TiO2 layer thicknesses (30 - 65 nm, depending on the experimental conditions) are found for unirradiated and irradiated laboratory specimens. The TiO2 layer formed on the in-situ corrosion specimens (33 nm / 5.3 years) is thinner than that of the laboratory specimens (58 nm / 191 days) indicating less aggressive conditions in the field experiments. In view of these results, the alloy Ti99.8-Pd continues to be considered as a strong candidate container material and will be further investigated.

An experimental investigation of Top of Line Corrosion in a static CO<sub>2</sub> environment

CORROSION ◽  
10.5006/3548 ◽  
2021 ◽  
Author(s):  
Sheyla de Carvalho ◽  
Richard Barker ◽  
MARIANA FOLENA ◽  
Mohaamed Al-Khateeb ◽  
JOSE ANTONIO PONCIANO GOMES ◽  
...  
Keyword(s):  
Mass Loss ◽  
Gas Flow ◽  
Corrosion Behaviour ◽  
General Corrosion ◽  
Condensation Rate ◽  
Experimental Conditions ◽  
Corrosion Rates ◽  
Water Condensation ◽  
Surface Temperatures

&lt;i&gt;This paper presents an experimental and theoretical investigation into water condensation and corrosion under non-corrosion product forming conditions at the top of line in a static, CO&lt;sub&gt;2 &lt;/sub&gt;environment. An experimental test cell is developed to measure droplet lifetimes, condensation rates, as well as in situ and integrated corrosion rates (using miniature electrodes and mass loss specimens, respectively), as a function of the surface and gas temperatures, when the gas flow is dominated by natural convection. Experimental results show clearly that that water condensation rate (WCR) is not very influential on corrosion rate at low surface temperatures (T&lt;sub&gt;s&lt;/sub&gt;) (particularly below 25&lt;sup&gt;o&lt;/sup&gt;C) but becomes much more important at higher surface temperatures (&gt;40&lt;sup&gt;o&lt;/sup&gt;C). These findings are summarised in a new empirical correlation for TLC rate as a function of the condensation rate and surface temperature. A model for condensation at the top of the line for static, buoyancy-driven conditions is also presented and is shown to predict dropwise condensation rates accurately for a range of experimental conditions. The developed miniature electrodes for in situ electrochemical measurement are shown to provide an accurate interpretation of the transient response in general corrosion behaviour by giving real-time corrosion rates to complement the mass loss measurement.&lt;/i&gt;

Patterns of Incorporation of 75Se-Methionine into Fibrinogen and Other Plasma Proteins in Rabbits Stimulated by Different Test Conditions

1973 ◽  
Vol 29 (01) ◽  
pp. 076-086 ◽  
Author(s):  
Uri Seligsohn ◽  
Samuel I. Rapaport ◽  
Ariella Zivelin
Keyword(s):  
Growth Hormone ◽  
Plasma Proteins ◽  
Tissue Injury ◽  
Injury Pattern ◽  
Experimental Conditions ◽  
Test Conditions

SummaryRabbits were injected with 75Se-Methionine (75SeM) 4-8 hr after being subjected to a variety of experimental conditions: injection of ACTH, growth hormone, glucagon, adrenalin, endotoxin, turpentine, hydrocortisone and laparotomy. All of these experimental conditions except injection of glucagon were associated with increased incorporation of 75SeM into fibrinogen. Three patterns of incorporation of 75SeM into plasma proteins were recognized: 1. the pituitary pattern, which was observed in animals injected with ACTH, growth hormone or endotoxin, and which was characterized by increased incorporation of 75SeM only into fibrinogen and by a delayed incorporation of 75SeM into α2 and β1 globulins; 2. the tissue injury pattern, which was characterized by a markedly increased incorporation of 75SeM into fibrinogen and no alteration in incorporation of 75SeM into α2 or β1 globulins; and 3. the pharmacologic corticosteroid pattern, which was characterized by a moderately increased incorporation of 75SeM into fibrinogen and a strikingly increased incorporation of 75SeM into α2 and β1 globulins.

In situ monitoring of isophorone diisocyanate-based flexible polyurethane foams formation

2016 ◽  
Vol 54 (1) ◽  
pp. 37-52 ◽  
Author(s):  
I Eceiza ◽  
L Irusta ◽  
A Barrio ◽  
MJ Fernández-Berridi
Keyword(s):  
Foam Height ◽  
Polyurethane Foams ◽  
In Situ Monitoring ◽  
Generation Process ◽  
Isophorone Diisocyanate ◽  
Experimental Conditions ◽  
Foaming Process ◽  
Foam Generation ◽  
Flexible Polyurethane

Novel isophorone diisocyanate-based flexible polyurethane foams were prepared by the one-step method in a computerized foam qualification system (FOAMAT). The experimental conditions to obtain this type of foams, in relation to the nature and concentration of catalysts as well as the reaction temperature, were established as no data were available in scientific literature. The chemical reactions occurring during the foam generation process were monitored in situ by attenuated total reflectance-FTIR spectroscopy. The kinetics of the foam generation was fitted to an nth order model and the data showed that the foaming process adjusted to a first-order kinetics. The physical changes as pressure, foam height, and dielectric polarization were monitored by the FOAM software (FOAMAT). According to these parameters, the foaming process was divided into four steps: bubble growth, bubble packing, cell opening, and final curing.

scholarly journals Application of an enzymatic cascade reaction for the synthesis of the emeraldine salt form of polyaniline

2021 ◽  
Author(s):  
Minoru Kurisu ◽  
Reinhard Kissner ◽  
Masayuki Imai ◽  
Peter Walde
Keyword(s):  
Cascade Reaction ◽  
Emeraldine Salt ◽  
Salt Form ◽  
Experimental Conditions ◽  
Peroxidase Isoenzyme ◽  
Large Unilamellar Vesicles ◽  
Dark Green ◽  
Catalyzed Oxidation ◽  
Reference Reaction

AbstractThe synthesis of the emeraldine salt form of polyaniline (PANI-ES) from aniline with Aspergillus sp. glucose oxidase (GOD), d-glucose, dissolved O2, and horseradish peroxidase isoenzyme C (HRPC) in the presence of large unilamellar vesicles of AOT (sodium bis-(2-ethylhexyl)sulfosuccinate) as templates at pH = 4.3 and T ~ 25 °C was investigated in a systematic way. In this cascade reaction mixture, the oxidation of aniline is catalyzed by HRPC with H2O2 that is formed in situ as byproduct of the GOD-catalyzed oxidation of d-glucose with O2. Under the elaborated experimental conditions which we considered ideal, the formation of PANI-ES products is evident, as judged by UV/Vis/NIR and EPR measurements. Comparison was made with a reference reaction, which was run under similar conditions with added H2O2 instead of GOD and d-glucose. Although the reference reaction was found to be superior, with the cascade reaction, PANI-ES products can still be obtained with high aniline conversion (> 90%) within 24 h as stable dark green PANI-ES/AOT vesicle dispersion. Our results show that the in situ formation of H2O2 does not prevent the inactivation of HRPC known to occur in the reference reaction. Moreover, the GOD used in the cascade reaction is inactivated as well by polymerization intermediates.

The Effect of Lesion Characteristic on Remineralization and Model Sensitivity

1992 ◽  
Vol 71 (3_suppl) ◽  
pp. 811-813 ◽  
Author(s):  
F. Schäfer ◽  
S.J. Raven ◽  
T.A. Parr
Keyword(s):  
Real Life ◽  
High Sensitivity ◽  
Lesion Size ◽  
Experimental Conditions ◽  
Treatment Groups ◽  
Human Enamel ◽  
Enamel Sample ◽  
Two Factors ◽  
Treatment Bias

A major criterion for assessing the value of any experimental model in scientific research is the degree of correspondence between its results and data from the real-life process it is designed to model. Intra-oral models aimed at predicting the anti-caries efficacy of toothpastes or other topical treatments should therefore be calibrated against treatments proven to be effective in a caries clinical trial. For this to be achieved, it is necessary that a model with high sensitivity be designed, while at the same time retaining relevance to the process to be modeled. This means that the effects of the various experimental conditions and parameters of the model on its performance must be understood. The purpose of this paper was to assess the influence of two specific factors on the performance of an in situ enamel remineralization model, which is based on human enamel slabs attached to partial dentures. The two factors are initial lesion severity and origin of enamel sample. The results indicated that initial lesion size affected whether net remineralization or net demineralization occurred during in situ treatment. Samples with an initial range of from 1500 to 2500 (ΔZ) tended more toward demineralization than did samples with ΔZ > 3500. This means that treatment groups must be well-balanced with respect to initial lesion size. Differences in initial demineralization severity between different tooth locations must also be considered so that systematic treatment bias can be avoided. The solution used in the model discussed here is based on a balanced experimental design, which allows this effect to be taken into account in the data analysis.

scholarly journals Microbial Functional Gene Diversity with a Shift of Subsurface Redox Conditions duringIn SituUranium Reduction

2012 ◽  
Vol 78 (8) ◽  
pp. 2966-2972 ◽  
Author(s):  
Yuting Liang ◽  
Joy D. Van Nostrand ◽  
Lucie A. N′Guessan ◽  
Aaron D. Peacock ◽  
Ye Deng ◽  
...  
Keyword(s):  
Functional Diversity ◽  
Field Experiments ◽  
Gene Diversity ◽  
Functional Gene ◽  
Redox Conditions ◽  
Functional Genes ◽  
Microbial Functional Diversity ◽  
Content Type ◽  
Microbial Functional Gene

ABSTRACTTo better understand the microbial functional diversity changes with subsurface redox conditions duringin situuranium bioremediation, key functional genes were studied with GeoChip, a comprehensive functional gene microarray, in field experiments at a uranium mill tailings remedial action (UMTRA) site (Rifle, CO). The results indicated that functional microbial communities altered with a shift in the dominant metabolic process, as documented by hierarchical cluster and ordination analyses of all detected functional genes. The abundance ofdsrABgenes (dissimilatory sulfite reductase genes) and methane generation-relatedmcrgenes (methyl coenzyme M reductase coding genes) increased when redox conditions shifted from Fe-reducing to sulfate-reducing conditions. The cytochrome genes detected were primarily fromGeobactersp. and decreased with lower subsurface redox conditions. Statistical analysis of environmental parameters and functional genes indicated that acetate, U(VI), and redox potential (Eh) were the most significant geochemical variables linked to microbial functional gene structures, and changes in microbial functional diversity were strongly related to the dominant terminal electron-accepting process following acetate addition. The study indicates that the microbial functional genes clearly reflect thein situredox conditions and the dominant microbial processes, which in turn influence uranium bioreduction. Microbial functional genes thus could be very useful for tracking microbial community structure and dynamics during bioremediation.

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