D.S. Antropov and M.S. Veshchunov
A new recently proposed mechanism of the lenticular grain face bubble migration which controls the bubble mobility and determines the drag force exerted on the grain boundary, is…
Abstract
A new recently proposed mechanism of the lenticular grain face bubble migration which controls the bubble mobility and determines the drag force exerted on the grain boundary, is further developed in application to the peripheral (edge and corner) intergranular bubbles. It is shown that contribution of the peripheral bubbles to the retarding effect can be significant, especially under irradiation conditions with high fission rates in UO2 fuel. In addition, simultaneous consideration of intergranular bubbles and pores evolution allows further improvement of the model predictions for grain growth under irradiation conditions. The improved model was implemented in the integral code MFPR, which is designed for modelling of fission product release from irradiated UO2 fuel, and validated against various tests under irradiation and annealing conditions with various types (dense and porous) fuel pellets.
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M.N. Desai and S.M. Desai
Mann, Antonucci, Nathan, Hackerman and Antropov investigated aniline and N — substituted methyl and ethylamines as corrosion inhibitors for iron in acidic media. The present study…
Abstract
Mann, Antonucci, Nathan, Hackerman and Antropov investigated aniline and N — substituted methyl and ethylamines as corrosion inhibitors for iron in acidic media. The present study was therefore undertaken to investigate the retardation of corrosion of aluminium 65S in hydrochloric acid.
Alexander P. Sukhodolov, Elena G. Popkova and Tatiana N. Litvinova
This chapter is aimed at the elimination of contradictions and the development of a strong and transparent theoretical basis for studying information economy, with the goal of…
Abstract
Purpose
This chapter is aimed at the elimination of contradictions and the development of a strong and transparent theoretical basis for studying information economy, with the goal of determining the basic characteristics of information economy and compiling its conceptual model.
Methodology
The research methods include the methods of systemic, logical, structural and functional analysis, synthesis, induction, deduction, method of modeling socioeconomic systems, and method of graphical presentation of information. The authors also use the noosphere research method that allows for the viewing of the information economy as a noosphere and studying the role, interdependencies, and results of interaction between its components – the technosphere, sociosphere, and economic sphere.
Results
As a result, the authors develop and present a graphical conceptual model of information economy, in which the noosphere is in the form of a pyramid. The pyramid is based on technosphere – spheres of economy in which information and information and communication technologies are produced, which provides technological support for information economy. The pyramid’s center is occupied by sociosphere – information society – which is the social core of information economy, in which the constant exchange of electronic information between economic subjects in information economy and outside of it due to its openness takes place. The pinnacle is occupied by economic sphere – economic tip of information economy – in which information and information and communication technologies are used in economic activities, and informatization (transfer into electronic form) of all spheres of economy takes place. The flows of resources and information move from the foundation of the pyramid to its pinnacle, due to which the target result is maximized – intensity of creation and effectiveness of using new information – which is knowledge and technologies.
Recommendations
The authors recommend the use of the presented graphical illustration for studying the conceptual model of information economy.
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To investigate the capability of a series of nitrogen‐based heterocyclic organic compounds in inhibiting corrosion of iron in HCl and elucidate the dominant active form of the…
Abstract
Purpose
To investigate the capability of a series of nitrogen‐based heterocyclic organic compounds in inhibiting corrosion of iron in HCl and elucidate the dominant active form of the applied compounds during the adsorption process to explore the mechanism of their action.
Design/methodology/approach
The tested compounds were pyrimidine containing compounds, which were selected, based on molecular structure considerations. Gravimetric method has been applied with various electrochemical techniques (polarisation resistance, polarisation curves and electrochemical impedance spectroscopy) to investigate inhibition efficiency and mechanism.
Findings
The inhibiting action of the investigated pyrimidine containing compounds depends primarily on their concentration and molecular structure. These compounds act as mixed type inhibitors and function via adsorption on the surface, which follows Frumkin adsorption isotherm. The inhibition by the tested pyrimidine derivatives could be attributed to their chemisorption on the metal surface forming donor/acceptor type of bond between the inhibitor molecules and the vacant d orbitals of the surface iron atoms. Contribution from electrostatic adsorption, via interaction between the protonated form of the inhibitor and the charged metal surface, is also possible.
Research limitations/implications
The applied inhibitors were tested in the presence of chloride ions as a corrosive medium. Whether these inhibitors will function well in the presence of other ions that are typically present in natural corrosive environment is unknown.
Originality/value
This paper provides useful information regarding inhibition effect of pyrimidine and series of its derivatives. The outcome of this work contributes to better understanding of the mechanism of inhibition by this class of N‐based heterocyclic organic compounds.
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Last month we published abstracts and summaries of some of the papers presented at the Congress, which was held at the Imperial College of Science and Technology from April 10–15…
Abstract
Last month we published abstracts and summaries of some of the papers presented at the Congress, which was held at the Imperial College of Science and Technology from April 10–15 under the auspices of the International Union of Pure and Applied Chemistry. In this issue we publish further abstracts and summaries together with illustrations of many of the corrosionists attending and photographs of some of the many visits which were arranged to works and laboratories. The Congress attracted over 800 delegates.
Certain classes of organic chemicals that can behave like carbon black in protecting polythene from thermal degredation have recently been developed at Bell Telephone laboratories…
Abstract
Certain classes of organic chemicals that can behave like carbon black in protecting polythene from thermal degredation have recently been developed at Bell Telephone laboratories in the U.S.A. Mrs. A. Worthington and Dr. W. L. Hawkins described their discovery at a recent meeting of the American Chemical Society in New York. They demonstrated that a number of compounds containing alternating unsaturated bonds provide excellent thermal anti‐oxidant properties in combination with previously reported sulphur‐bearing compounds.
M.N. Desai, G.H. Thanki and M.H. Gandhi
Organic compounds containing sulphur, nitrogen and oxygen atoms are capable of retarding metallic corrosion. As the thiourea molecule contains one sulphur and two nitrogen atoms…
Abstract
Organic compounds containing sulphur, nitrogen and oxygen atoms are capable of retarding metallic corrosion. As the thiourea molecule contains one sulphur and two nitrogen atoms, thiourea and its derivatives are potential corrosion inhibitors. While extensive investigations have been carried out on inhibitor properties of thiourea, due attention has not yet been paid to a systematic study of inhibitor action of thiourea derivatives. However, several substituted thioureas have been investigated as corrosion inhibitors. The applications of thiourea and its derivatives as corrosion inhibitors reported in literature up to 1967 are narrated in this article.
Resit Yildiz and Basak Dogru Mert
This paper aims to study inhibitory effect of 4-aminothiophenol on the corrosion of mild steel (MS) in 0.5 M HCl.
Abstract
Purpose
This paper aims to study inhibitory effect of 4-aminothiophenol on the corrosion of mild steel (MS) in 0.5 M HCl.
Design/methodology/approach
In this study, electrochemical experiments, quantum chemical calculations, potentiodynamic measurements, linear polarization resistance and scanning electron microscopy were used.
Findings
The experimental results suggest that this compound is efficient corrosion inhibitor and the inhibition efficiencies increase with increasing their (from 0.5 to 10.0 mM.) concentrations. This reveals that inhibitive actions of inhibitors were mainly due to adsorption on mild steel surface. The adsorption of these inhibitors was found to obey Langmuir adsorption model. The computed quantum chemical features show good correlation with empirical inhibition efficiencies.
Originality/value
The 4-aminothiophenol is suitable inhibitor for application in closed-circuit systems against corrosion. The study is original and has great impact in industrial area. The obtained theoretical results have been adapted with the experimental data.
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M.N. Desai, S.M. Desai, M.H. Gandhi and C.B. Shah
The discovery of the Hall‐Herqult process for the manufacture of aluminium made it possible to obtain the metal in large quantities. Soon it attained the position of a major…
Abstract
The discovery of the Hall‐Herqult process for the manufacture of aluminium made it possible to obtain the metal in large quantities. Soon it attained the position of a major industrial metal due to its lightness combined with strength, capacity to take up a high polish, excellent conductivity of heat and electricity. Moreover it gives a wide range of extremely valuable alloys with diverse elements such as copper, magnesium, nickel, silicon, zinc, etc.
S. Muralidharan, P. Chandrakumari, K. Madhavan, T. Vasudevan and S. Venkatakrishna Iyer
Introduction Amines have been known for a number of years as effective corrosion inhibitors. Their efficiency is attributed to the presence of the nitrogen atom acting as the…
Abstract
Introduction Amines have been known for a number of years as effective corrosion inhibitors. Their efficiency is attributed to the presence of the nitrogen atom acting as the active centre for the adsorption of organic molecules on the metal surface. Several aliphatic and aromatic amines have been reported to serve as effective corrosion inhibitors for iron and steel in acidic solutions. The nitrogen‐containing corrosion inhibitor exhibited a very good performance in hydrochloric acid, but very little effect in sulphuric acid. Hence a study of the mechanism by which the corrosion rate is reduced when these organic compounds are added to solutions is of interest. In this study the inhibition of corrosion of mild steel in HCl and H2SO4 has been studied using different electrochemical techniques. Results are reported and discussed.