scholarly journals Anodisation of Aluminium in Aqueous Sodium Oxalate and Sodium Sulphate Media

2013 ◽  
Vol 38 ◽  
pp. 9-16
Author(s):  
CM Mustafa ◽  
MA Habib ◽  
MS Islam
Keyword(s):  
Reference Electrode ◽  
Visual Observation ◽  
Sodium Sulphate ◽  
Sodium Oxalate ◽  
Aqueous Sodium ◽  
Surface Breakdown ◽  
Constant Potential ◽  
Sulphate Media ◽  
Concentration Graphs ◽  
Current Potential

An investigation was conducted on the anodisation of commercial grade aluminium in aqueous sodium sulphate and sodium oxalate solutions. The parameters investigated were anodisation potential and electrolyte composition. Degree of anodisation was evaluated by visual observation of the anodised surface, analyses of current-concentration graphs at constant potential and current-potential characteristics, and measurement of corrosion rate of the anodised surface. Anodisation potential played an important role on the degree of anodisation. The optimum potential was 400 mV and 800 mV wrt saturated Ag/AgCl (SSE) reference electrode for sodium sulphate and sodium oxalate solutions respectively. Below and above the optimum potential poor anodisation was due to insufficient production of Al3+ to form anodic film and surface breakdown respectively. Anodisation increased with the increase of oxalate concentration. Sulphate concentration was less effective on the degree of anodisation. Between the two electrolytes sodium oxalate was more suitable than sodium sulphate for aluminium anodisation. DOI: http://dx.doi.org/10.3329/rujs.v38i0.16544 Rajshahi University J. of Sci. 38, 09-16 (2010)

EUROPIUM OXALATE ION ASSOCIATION IN WATER

1966 ◽  
Vol 44 (24) ◽  
pp. 3057-3062 ◽  
Author(s):  
P. G. Manning
Keyword(s):  
Acetic Acid ◽  
Ionic Strength ◽  
Stability Constant ◽  
Stability Constants ◽  
Aqueous Phase ◽  
Sodium Acetate ◽  
Ion Association ◽  
Sodium Oxalate ◽  
Aqueous Sodium ◽  
Oxalate Ion

The partitioning of radiotracer 152/151Eu between aqueous sodium oxalate (Na2L) solutions and toluene solutions of thenoyltrifluoroacetone (HTTA) has been studied as a function of the oxalate concentration. The pH of the aqueous phase was controlled by means of sodium acetate – acetic acid mixtures and the ionic strength (I) by NaCl or NaClO4.At low ionic strengths (~0.05) and [L] ~10−4 M EuL+ formed, but at I = 0.95 and [L] ~10−3 M EuL2− also formed. Stability constants for the 1:1 and 1:2 (metal:ligand) complexes are reported.The magnitudes of the stepwise stability constant ratios are discussed.

Spectroelectrochemical Investigation of Pentacarbonyl(pyrazine)metal(0) (Metal = Cr, Mo, W) Complexes of Group 6 Elements

2002 ◽  
Vol 57 (1) ◽  
pp. 92-98 ◽  
Author(s):  
Şeniz Özalp Yaman ◽  
Emren Esentürk ◽  
Ceyhan Kayran ◽  
Ahmet M. Önal
Keyword(s):  
Cyclic Voltammetry ◽  
Electrochemical Behaviour ◽  
Reference Electrode ◽  
Constant Current ◽  
Oxidation Peak ◽  
Group 6 ◽  
Constant Potential ◽  
Electrochemical Mechanism ◽  
Temperature Constant

The electrochemical behaviour of pentacarbonyl(pyrazine)metal(0) complexes of the group 6 elements was studied by cyclic voltammetry in dichloromethane-(n-Bu)4NBF4 solventelectrolyte couple at -20°C vs. Ag/Ag+ or SCE reference electrode. Constant potential electrolyses of the complexes were carried out at their first oxidation peak potentials and monitored in situ by UV-Vis spectrometry. Electrolysis of W(CO)5pz produces [W(CO)5pz]+ and a similar electrochemical mechanism is expected both for Cr(CO)5pz and Mo(CO)5pz complexes. In situ low temperature constant current ESR electrolysis also confirmed the production of [W(CO)5pz]+ after the electron transfer.

Hydration and Ion Pairing in Aqueous Sodium Oxalate Solutions

ChemPhysChem ◽  
2003 ◽  
Vol 4 (4) ◽  
pp. 373-378 ◽  
Author(s):  
Richard Buchner ◽  
Faradj Samani ◽  
Peter M. May ◽  
Peter Sturm ◽  
Glenn Hefter
Keyword(s):  
Ion Pairing ◽  
Sodium Oxalate ◽  
Aqueous Sodium

Inhibition of copper corrosion in acidic sulphate media by eco-friendly amino acid compound

2014 ◽  
Vol 68 (3) ◽  
Author(s):  
Ana Simonović ◽  
Marija Petrović ◽  
Milan Radovanović ◽  
Snežana Milić ◽  
Milan Antonijević
Keyword(s):  
Corrosion Inhibitor ◽  
Open Circuit ◽  
Sodium Sulphate ◽  
Copper Electrode ◽  
Sulphate Solution ◽  
Protective Film ◽  
Copper Corrosion ◽  
Sulphate Media ◽  
Acid Compound ◽  
Acidic Sulphate

AbstractThis investigation aimed to study a “green” non-toxic biodegradable copper corrosion inhibitor in an acidic sodium sulphate solution. The methods used in the investigation of cysteine as a copper corrosion inhibitor in an acidic sodium sulphate solution were: potentiodynamic measurements, open circuit potential measurements, and chronoamperometric measurements. Optical microscopy was used in addition to electrochemical methods. Potentiodynamic measurements show that cysteine has good inhibitory properties in an acidic medium. Polarisation curves indicate that the presence of cysteine in a sulphate solution decreases the current density and that using various cysteine concentrations results in the formation of a protective film on the surface of the electrode due to the formation of the Cu(I)-cys complex. These results are confirmed by chronoamperometric measurements. Furthermore, it is clear from microphotographs that a protective film does form on copper electrode in the presence of cysteine. The Langmuir adsorption isotherm indicates that cysteine is chemisorbed on the surface of the electrode.

scholarly journals Corrosion Inhibition of Al-Si-Cu Alloy in the Basic Media by UsingSix Inhibitors at Four Temperatures

2008 ◽  
Vol 5 (3) ◽  
pp. 427-436
Author(s):  
Baghdad Science Journal
Keyword(s):  
Sodium Sulphate ◽  
Inorganic Materials ◽  
Sodium Oxalate ◽  
Effect Of Temperature ◽  
Sodium Chromate ◽  
Solution Ph ◽  
Protection Efficiency ◽  
Cu Alloy ◽  
Naoh Solution ◽  
Polarization Behaviour

The research involved attempt to inhibit the corrosion of Al-Si-Cu alloy in 2.5x10-3 mol.dm-3 NaOH solution (pH=11.4) by addition of six different inhibitors with three concentrations (1x10-3, 1x10-2, and 0.1 mol.dm-3). These inhibitors include three organic materials (sodium acetate, sodium benzoate, and sodium oxalate) and three inorganic materials (sodium chromate, disodium phosphate, and sodium sulphate). The data that concerning polarization behaviour are calculates which include the corrosion potential (Ecorr) and current density (icorr), cathodic and anodic Tafel slopes (bc & ba), and polarization resistance (Rp). Protection efficiency (P%) and activation energy (Ea) values were calculated for inhibition by the six inhibitors. The results indicated the effect of temperature on the inhibition in basic media.

scholarly journals The Relationship between Neuropsychological Performance and Level of Direct Current Potential in Patients with Occupational Diseases from Exposure to Physical Factors

2021 ◽  
Vol 6 (1) ◽  
pp. 94-100
Author(s):  
O. I. Shevchenko ◽  
O. L. Lakhman
Keyword(s):  
Direct Current ◽  
Occupational Diseases ◽  
Group Iv ◽  
Physical Factors ◽  
Group Iii ◽  
Dc Potential ◽  
Constant Potential ◽  
The Brain ◽  
Current Potential ◽  
Potential Level

The aim of the study was to identify the peculiarities of neuropsychological indices disorders depending on changes in the level of constant potential in patients with occupational diseases as a result of physical factors.Materials and methods. The study involved 60 patients with vibration disease caused by local vibration (group I), 106 patients with vibration disease caused by combined exposure to local and general vibration (group II), 101 civil aviation pilots with an established diagnosis of professional sensorineural hearing loss (group III), and 50 healthy men (group IV, comparison group) who were not exposed to vibration and noise due to the specifics of their professional activities. Methods of neuro-energy mapping and neuropsychological testing were used.Results. In groups I–II, compared with group IV, an increase in local levels of constant potential (DC-potential level) in the central, right temporal, and central frontal parts of the brain (2.3 (6.5–3.8) mV; –0.3 (–2.1–2.1); 2.1 (–3.4–6.8) and –0.3 (–3.1–4.3); –2.24 (–6.4–3.8); 0.9 (–3.1–8.5) mV at p = 0.005, 0.007 and 0.004 respectively). Differences in the values of DC-potential level gradients in individuals of group III when compared with group IV reached the level of significance in the central, temporal, occipital leads relative to the central frontal (–5.0 (–13.1–3.8); –4.1 (–9.4–5.1); –2.1 (–10.9–6.6); –6.3 (–15.3–1.8) and 2.9 (–3.0–10.6); 2.2 (–4.5–13.8); 5.6 (–7.6–14.1); –1.4 (–7.5–3.9) mV at p = 0.008; 0.009; 0.009, and 0.007 respectively). Cognitive disorders in patients of groups I–III when compared with group IV correspond to a mild disorder of dynamic, constructive praxis and expressive speech (1.40 (0–1,6); 1.43 (0–1,7); 1.2 (0–1,5) and 0.3 (0–1); 0.2 (0–1); 0.06 (0–1) points at p = 0.008, 0.008 and 0.009 respectively).Conclusions. A common neurofunctional sign of a mild impairment of the cognitive sphere in occupational diseases caused by physical factors is an increase in direct current potential level in the frontal-central and parieto-occipital regions, predominantly of the left hemisphere of the brain.

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