scholarly journals The theory of metallic corrosion in the light of quantitative measurements.—Part IV

1931 ◽  
Vol 131 (817) ◽  
pp. 494-517 ◽  
Keyword(s):  
Potassium Chloride ◽  
Oxygen Supply ◽  
Experimental Methods ◽  
Metallic Surface ◽  
Potassium Sulphate ◽  
Corrosion Rates ◽  
Quantitative Measurements ◽  
Series Of Experiments ◽  
Metallic Corrosion ◽  
Reactive Metals

The present paper includes some experiments suggested by criticisms of Part III of the research, and describes work upon the effect of depth of im­mersion on the corrosion of zinc in potassium chloride solutions. Some of the factors which influence the distribution of corrosion over the metallic surface are discussed with particular reference to the effect of differential aeration. Curves are given showing the effect of concentration of potassium chloride and potassium sulphate on the initial corrosion rate of zinc in tranquil conditions. The experimental methods used are those described in previous papers, supple­mented by micrographic work and a few potential measurements. The criticism has been made that the tranquil conditions in which the present series of experiments is being conducted cause abnormally slow rates of oxygen supply which dictate the corrosion rates; these, therefore, are not considered characteristic of the metal under test, but merely of the rate of penetration of oxygen through the liquid and any corrosion products which cover the metal. It has also been suggested that much faster rates of oxygen supply would be required to bring out the true corrosion characteristics of a metal or even to differentiate between two fairly reactive metals.

scholarly journals The theory of metallic corrosion in the light of quantitative measurements.— Part II

1928 ◽  
Vol 121 (787) ◽  
pp. 88-121 ◽  
Keyword(s):  
Potassium Chloride ◽  
Initial Period ◽  
Metallic Zinc ◽  
Dilute Solutions ◽  
Experimental Conditions ◽  
Limited Volume ◽  
Quantitative Measurements ◽  
Chlorine Ions ◽  
Oxygen Gas ◽  
Metallic Corrosion

In a previous paper it was shown that if dilute solutions of potassium chloride were allowed to act upon metallic zinc in the presence of oxygen, the corrosion-time curves obtained by means of the observed absorption of oxygen gas were exponential for part of their course. The reason why this particular form of curve was obtained was considered to be the gradual falling off in the concentration of chlorine ions in the experimental conditions of limited volume of solution. For N/10000 and N/5000 solutions the agreement between the experimental and calculated curves was satisfactory up to about 25 days except for a short initial period of two or three days. After about 25 days the experimental curves fell notably below the calculated values, and the suggestion that the reason for this discrepancy was mainly the barring out of chlorine ions from the anodic areas by means of accumulations of corrosion products received some support from the fact that chlorine ions were actually found in solution even after long periods of experiment with the N/5000 solution, in which this discrepancy was most pronounced, but since none were found in the more dilute solutions it seemed probable that some other factor was also operative.

scholarly journals The theory of metallic corrosion in the light of quantitative measurements. Part VI.— The distribution of corrosion

1933 ◽  
Vol 140 (841) ◽  
pp. 399-425 ◽  
Keyword(s):  
Mild Steel ◽  
Metal Surface ◽  
Salt Concentration ◽  
Oxygen Supply ◽  
Irregular Distribution ◽  
Quantitative Measurements ◽  
Physical Heterogeneity ◽  
Wide Range ◽  
Protective Films ◽  
Metallic Corrosion

In previous parts of this research it has been shown that the rate of oxygen supply to the whole metal surface is the factor which generally controls the rates of corrosion of zinc and mild steel in the conditions studied, though other factors may affect them appreciably in special conditions. Such factors are the evolution of hydrogen and the formation of protective films or masses of corrosion products which may result from increased alkalinity, or other causes. Neither the basic potential of the metal nor the conductivity of the electrolyte exercised control over a wide range of salt concentration. Corrosion distribution was at first sporadic but was soon concentrated at a few large irregularly shaped areas. For many purposes distribution is more important than the total amount of corrosion, especially when it is so localized as to be called pitting. The irregular distribution of corrosion was formerly believed to be caused by chemical and physical heterogeneity of the metal, but differential aeration is now usually believed to be a more frequent cause of local corrosion and this view was accepted in Parts I to III of this research.

EXPERIMENTAL STUDY OF REACTION OF ETHANOL WITH OXYGEN BEHIND SHOCK WAVES USING ATOMIC RESONANCE ABSORPTION SPECTROSCOPY METHOD

2020 ◽  
Author(s):  
N. S. Bystrov ◽  
◽  
A. V. Emelianov ◽  
A. V. Eremin ◽  
P. I. Yatsenko ◽  
...  
Keyword(s):  
Experimental Study ◽  
Shock Waves ◽  
Absorption Spectroscopy ◽  
Vacuum Ultraviolet ◽  
Resonance Absorption ◽  
Atomic Resonance ◽  
Quantitative Measurements ◽  
Series Of Experiments ◽  
Kinetics Of Reaction ◽  
Oxygen Atoms

The kinetics of reaction of C2H5OH with N2O behind shock waves is studied. The quantitative measurements of the time profiles of concentration of O atoms were carried out by the method of atomic resonance absorption spectroscopy (ARAS) using resonance vacuum-ultraviolet line of O-atom at 130.5 nm. For the calibration of absorption intensity of oxygen atoms depending on its concentration, the special series of experiments in the mixture containing different amounts of N2O in Ar was carried out at T = 2100 ± 50 K when molecule of N2O is completely dissociated. An experimental study of the appearance and consumption of oxygen atoms during the reaction of ethanol with oxygen in mixture 10 ppm N2O + (10 ... 0.1) ppm C2H5OH + Ar at temperatures of 16002300 K and pressures of 200-300 kPa have been carried out. A kinetic analysis of obtained data was performed using the Chemkin package.

Salt effect in hydrolysis of 3-acyl-1,3-diphenyltriazenes

1981 ◽  
Vol 46 (12) ◽  
pp. 3104-3109 ◽  
Author(s):  
Miroslav Ludwig ◽  
Oldřich Pytela ◽  
Miroslav Večeřa
Keyword(s):  
Sodium Chloride ◽  
Temperature Dependence ◽  
Potassium Chloride ◽  
Rate Constants ◽  
Zinc Sulphate ◽  
Salt Effect ◽  
Sodium Sulphate ◽  
Potassium Sulphate ◽  
Lithium Sulphate ◽  
Hydrolysis Of

Rate constants of non-catalyzed hydrolysis of 3-acetyl-1,3-diphenyltriazene (I) and 3-(N-methylcarbamoyl)-1,3-diphenyltriazene (II) have been measured in the presence of salts (ammonium chloride, potassium chloride, lithium chloride, sodium chloride and bromide, ammonium sulphate, potassium sulphate, lithium sulphate, sodium sulphate and zinc sulphate) within broad concentration ranges. Temperature dependence of the hydrolysis of the substrates studied has been measured in the presence of lithium sulphate within temperature range 20° to 55 °C. The results obtained have been interpreted by mechanisms of hydrolysis of the studied substances.

RECIPROCAL SALT PAIRS, INVOLVING THE CATIONS Li2, Na2, AND K2, THE ANIONS SO4, AND Cl2, AND WATER, AT 25 °C

1958 ◽  
Vol 36 (11) ◽  
pp. 1511-1517 ◽  
Author(s):  
A. N. Campbell ◽  
E. M. Kartzmark ◽  
E. G. Lovering
Keyword(s):  
Sodium Chloride ◽  
Potassium Chloride ◽  
Mole Fraction ◽  
Lithium Chloride ◽  
Invariant Point ◽  
Double Salt ◽  
Potassium Sulphate ◽  
Lithium Sulphate ◽  
Solid Phases ◽  
Chloride Monohydrate

In the reciprocal salt pair Li2, K2, Cl2, SO4, and water, at 25 °C there are large areas in which potassium sulphate and potassium lithium sulphate (KLiSO4) are separately in equilibrium with solution. Two incongruent invariant points exist. At one of these the composition of the solution is 0.917 mole fraction chloride, 0.437 mole fraction lithium, and 19.4 moles of water per total mole of salt, the equilibrium solid phases being potassium chloride, potassium sulphate, and the double salt. At the second, the composition of the solution is 0.967 mole fraction chloride, 0.870 mole fraction lithium, and 13.8 moles of water per mole of salt, the solid phases being potassium chloride, double salt, and lithium sulphate monohydrate. One congruent invariant point exists, at which the composition of the solution is 1.00 mole fraction chloride, 0.960 mole fraction lithium, and 9.6 moles of water per mole of salt, the solid phases being lithium sulphate monohydrate, lithium chloride monohydrate, and potassium chloride.In the reciprocal salt pair Li2, Na2, Cl2, SO4, and water, at 25 °C there is an incongruent invariant point at which the composition of the solution is 0.873 mole fraction chloride, 0.668 mole fraction lithium, and 15.1 moles water per total mole of salt, the solid phases being sodium chloride, solid solution of sodium and lithium sulphates, and lithium sulphate monohydrate. A congruent invariant point exists, at which the composition of the solution is practically entirely lithium chloride, the solid phases present being lithium chloride monohydrate, lithium sulphate monohydrate, and sodium chloride.

The Indirect Observation of the Decay of Mesotrons: Italian Experiments on Cosmic Radiation, 1937––1943

2008 ◽  
Vol 38 (3) ◽  
pp. 353-404 ◽  
Author(s):  
Daniela Monaldi
Keyword(s):  
Phenomenological Models ◽  
Experimental Observation ◽  
Cosmic Radiation ◽  
Cosmic Ray ◽  
Experimental Methods ◽  
Experimental Results ◽  
Intermediate Mass ◽  
Microphysical Process ◽  
Series Of Experiments ◽  
Indirect Observation

Following the discovery of mesotrons (intermediate-mass particles) in cosmic radiation in the 1930s, a group of physicists originating in Italy participated in a series of experiments designed to permit the observation of the spontaneous decay of elementary particles. The experimental results were classified as "indirect observations" of the microphysical process of decay, and the development of experimental methods was regarded as a progression toward increasing observational directness. This paper traces the activities of the cosmic-ray experimenters, viewing them as part of a stream in the international current of interest and research on the natural ββ radioactivity of the mesotrons. The paper pays particular attention to those aspects of experimental practice that the researchers associated with observational directness. I argue that the attribution of degrees of directness depended on the elimination of intrusive additional assumptions in the phenomenological models of the experiments. My study thus contributes to the analysis of experimental observation in microphysics.

scholarly journals The theory of metallic corrosion in the light of quantitative measurements

1927 ◽  
Vol 116 (774) ◽  
pp. 425-467 ◽  
Keyword(s):  
Relative Importance ◽  
Improved Method ◽  
Salt Solutions ◽  
Present Communication ◽  
Technical Problems ◽  
The Third ◽  
Quantitative Measurements ◽  
Number Of Factors ◽  
Metallic Corrosion

The principal object of the present research is the discovery of a satisfactory way of measuring the corrosion of metals in water and dilute salt solutions, and the use of it to test the adequacy of the newer electrochemical theory of corrosion as applied to such media. The theory suggests that a large number of factors can influence the rate of corrosion, but does not indicate quantita­tively their relative importance in given conditions, in fact, the theory is based at present upon qualitative or only roughly quantitative measurements. It is desirable, therefore, that a determined attempt should be made to place it upon a sounder basis, on account, both of the inherent interest of the theory and of its importance in technical problems of steadily increasing insistence. The present communication is the first portion of an extensive research; it is divided into three sections, the first gives an outline of the theory as understood by the authors; the second, a brief review of the kind of measurement upon which it rests; the third an improved method of measuring corrosion as applied to the metal zinc, together with an interpretation of the results so far obtained.

scholarly journals The effect of various treatments of culture medium upon the growth of certain fungal antagonists

1965 ◽  
Vol 37 (2) ◽  
pp. 84-88
Author(s):  
Leila-Riitta Erviö
Keyword(s):  
Potassium Chloride ◽  
Culture Medium ◽  
Oxygen Deficiency ◽  
Fungal Species ◽  
Potassium Sulphate ◽  
Coniothyrium Minitans ◽  
Mucor Hiemalis ◽  
Sclerotinia Trifoliorum ◽  
Rhizopus Nigricans ◽  
Ph Range

The addition of potassium chloride and potassium sulphate at a rate of 200 g/m2 to the culture medium had no effect on the growth of Sclerotinia trifoliorum, Acrostalagmus roseus I and II, Coniothyrium minitans, Gliocladium sp., Mucor hiemalis, M. spinosus, Sporotrichum carnis and Trichothecium roseum. Treatment of the culture medium with PCNB suppressed to some extent the development of A. roseus I and II, Gliocladium sp., C. minitans I and II, Mucor hiemalis and M. spinosus. The fungal species S. trifoliorum, Rhizopus nigricans and Sporotrichum carnis did not grow at all on PCNB-treated medium. S. trifoliorum, A. roseus I, Gliocladium sp., T. viride and T. roseum were able to grow in the pH range of 4—9. When the pH of the medium was 2, only T. viride grew. Oxygen deficiency suppressed the growth of S. trifoliorum, and the growth and the conidia formation of A. roseus I and II, M. hiemalis and T. viride.

Scale-up of stirred crystallisers. Batch precipitation of aluminium potassium sulphate

1982 ◽  
Vol 47 (11) ◽  
pp. 3027-3031 ◽  
Author(s):  
Piotr Karpiński ◽  
Stanislav Žáček ◽  
Jaroslav Nývlt ◽  
Jerzy Budz
Keyword(s):  
Size Distribution ◽  
Kinetic Constant ◽  
Scale Up ◽  
Potassium Sulphate ◽  
Aluminium Sulphate ◽  
Mixing Intensity ◽  
Mean Size ◽  
Relative Kinetic ◽  
Series Of Experiments ◽  
The Mean

Aluminium potassium sulphate has been precipitated batchwise by mixing equal volumes of 0.6 mol/l solutions of potassium sulphate and aluminium sulphate with eventual addition of water in advance. The experiments were performed at 20 and 25 °C in the volume 100 to 200 cm3 and in the volume 0.021 m3. From the size distribution of product crystals, the mean size of crystals has been evaluated and calculated the system kinetic constant of crystallization BN. The system constant is different in both series of experiments and can be correlated with the size of the crystallizer or with mixing intensity. Its value and the value of relative kinetic exponent g/n is comparable with the values obtained in experiments with cooling of solutions.

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