scholarly journals Experimental study of paint coatings resistance to osmotic destruction depending on water-soluble salts content on a metal surface

2019 ◽  
Vol 121 ◽  
pp. 02002
Author(s):  
Allanazar Atdaev ◽  
Arthur Mazitov ◽  
Rustam Akhmetgaliev

The main purpose of this work is to assess the relevance of the requirements for the quantitative content of water-soluble salts on the metal surface before applying an anti-corrosion coating. To do this, a series of tests are carried out by coating the metal surface of samples with different salt content, followed by aging in distilled water at high temperature and pressure. After exposure, the defects will be analyzed. The results obtained will help to choose the maximum allowable amount of soluble salts on the metal surface, because the internal coating of field pipelines is practically beyond repair, and to fix this value in the regulatory document.

1925 ◽  
Vol 15 (4) ◽  
pp. 407-419 ◽  
Author(s):  
A. F. Joseph

(1) The cotton growing area in the Gezira consists of a heavy clay soil, the proportion of clay being about 50–60 per cent. in the upper layers with a maximum at about the 4th foot.(2) The water soluble salts amount to about 0·2 per cent. The proportion is highest at about the 3rd to 5th foot. The alkalinity (pH) is highest at the 2nd foot.(3) In the first 2 feet, the salts consist mainly of sodium carbonate and the third and fourth of sodium sulphate.(4) The irrigation (Blue Nile) water is of excellent quality as judged by its natural chemical composition. The concentrated water, however, contains a very high proportion of alkali salts. It is estimated that a season of normal irrigation would cause an increase of 0·01 per cent. in the alkali content of the first 4 feet of soil.(5) The sodium salts can readily act on the clay and the sodium clay so formed hydrolyses with the formation of sodium carbonate.(6) Samples taken at the same time from good and bad plots in the same area show a strong correlation between salt content and cropyielding power. There is also a correlation between pH and fertility.(7) In the same season and in the same area, virgin (i.e. unirrigated) plots give a higher yield than those which have been previously under the same system of cultivation.


2021 ◽  
Vol 37 (6) ◽  
pp. 821-830
Author(s):  
Ha Nui Jo ◽  
Do Hyeon Nam ◽  
Mi Hyun Kim ◽  
Jae Sung Lee

The weapons excavated from the de-militarized zones (DMZ) of Korea are vulnerable to corrosion due to the immediate and drastic environmental change. Especially, the chloride ions (Cl⁻) in iron weapons cause active corrosion and require removal. In this study, conservation treatment and de-salination was performed for the discovered weapons from excavation sites of soldiers killed in action during the Korean War. Furthermore, an attempt was made to prepare the most stable plan for conservation treatment through the comparative study of soaking weapons in distilled water without chemicals and in a solution of sodium (SSC) at different temperatures. In the preliminarily experiments, the comparison of the eluted Cl⁻ ions according to different conditions of de-salination showed that the highest number of ions were detected from the de-salination with SSC at a temperature of 100℃, and its duration was much smaller, i.e., 1∼2 weeks. Accordingly, for the parts from the guns and rifles amongst other objects, a six-time de-salination was conducted in the SSC solution for 8 hours at 100℃ and subsequently, for 16 hours at room temperature during which the distilled water and SSC were exchanged every week. However, in the case of a loaded rifle, the de-salination was not conducted, considering the risk that the high temperature and pressure by impregnation in vacuum could cause an explosion


Author(s):  
Shabnam Ain ◽  
V Gupta ◽  
Babita K ◽  
Q Ain ◽  
J Dahiya

Aqueous solubility is a critical factor for optimum drug delivery. In the present study, we investigated the potential of drug-cyclodextrin complexation as an approach for improving the solubility and bioavailability of famotidine, an H2-receptor antagonist and acid reducing drug which has poor solubility and bioavailability. Solubility improvement of drug by β-cyclodextrin was done by simple complexation approach using physical, kneading and co-precipitation methods and compared with physical mixture. Phase solubility profile indicated that the solubility of famotidine was significantly increased in presence of β-cyclodextrin and shows a linear graph with β-cyclodextrin indicating formation of inclusion complexes in a 1:1 molar ratio. β-Cyclodextrin-famotidine mixture have maximum stability constant 1477.6 M-1. The inclusion complex ratio 1:1 of kneading mixture was selected based on drug release profile and compared with physical mixture. Further characterization was done by  using Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM) to identify the physicochemical interaction between drug and carrier and its effect on dissolution. Dissolution rate studies for selected inclusion complex was performed in 0.1 N HCl (pH 1.2), phosphate buffer (pH 7.5) and distilled water (pH 6.8) and compared these to pure drug profile which was found to be 2.34 fold increase in distilled water, 1.83 fold in HCl and 2.01 fold in phosphate buffer (pH 7.5). These results suggest that the kneaded complex of famotidine with β-cyclodextrin as hydrophilic complexation agent can substantially enhance the solubility and dissolution rate. Such complex has promising potential to improve the bioavailability of famotidine.  


1983 ◽  
Vol 48 (4) ◽  
pp. 1173-1186 ◽  
Author(s):  
Václav Bártl ◽  
Jiří Holubek ◽  
Emil Svátek ◽  
Marie Bartošová ◽  
Miroslav Protiva

Reactions of 10-(4-aminopiperazino)-10,11-dihydrodibenzo[b,f]thiepins XIVa-XIVd with benzaldehyde, 3,4-dimethoxybenzaldehyde, 4-dimethylaminobenzaldehyde, salicylaldehyde, 3-ethoxy-4-hydroxybenzaldehyde, 2-(2-dimethylaminoethoxy)benzaldehyde, 3-(2-dimethylaminoethoxy)benzaldehyde and 3-ethoxy-4-(2-dimethylaminoethoxy)benzaldehyde afforded a series of 19 hydrazones IIIa-Xc. Some of them showed the expected anticonvulsant effect but only towards pentetrazole; antagonism of maximal electroshock seizures was not observed. In general, the products have a character of tranquillizers: in higher does they produce central depression, potentiate the thiopental sleeping time, have hypothermic action; in single cases antiamphetamine, antireserpine, antihistamine and cataleptic effects were observed. The water-soluble salts of the basic hydrazones VIIIa, VIIIc, IXc and Xc, administered parenterally, showed a rather high acute toxicity and revealed also adrenolytic and hypotensive activity.


Minerals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 546
Author(s):  
Mateusz Ciszewski ◽  
Andrzej Chmielarz ◽  
Zbigniew Szołomicki ◽  
Michał Drzazga ◽  
Katarzyna Leszczyńska-Sejda

Industrial processing of mineral ores and concentrates generates large amounts of solid residues, which can be landfilled or further processed to recover selected elements depending on its economical profitability. Pressure leaching is a technology enabling high recovery of base metals like copper and zinc, transferring others like lead and iron to the solid residue. High temperature and pressure of such leaching leads to formation of sparingly soluble lead jarosite (plumbojarosite). The load of lead landfilled as solid residues resulting from such operation is so big that its recovery is perspective and crucial for waste-limiting technologies. This paper is devoted to lead extraction from pressure leaching residues using triethylenetetramine solution and then its precipitation as a commercial lead carbonate. The highest obtained recovery of lead was 91.3%. Additionally, presented technology allows to manage and recycle amine solution and reuse solid products. Produced pure lead carbonate can be directly added to smelting, not increasing temperature within the furnace.


2018 ◽  
Vol 213 ◽  
pp. 207-214 ◽  
Author(s):  
Michael Hack ◽  
Wolfgang Korte ◽  
Stefan Sträßer ◽  
Matthias Teschner

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