scholarly journals Assess the Effectiveness of protective Concrete coatings of microbiological sulfuric acid Aggression

2019 ◽  
Vol 97 ◽  
pp. 02022
Author(s):  
Viktor Sopov ◽  
Julia Danchenko ◽  
Ekaterina Latorez
Keyword(s):  
Sulfuric Acid ◽  
Building Structures ◽  
Predominant Role ◽  
Microbiological Processes ◽  
Repair Materials ◽  
Bactericidal Properties ◽  
Mineral Acids ◽  
Concrete Building ◽  
Modified Epoxy

Specification of corrosion processes in sewerage networks, the predominant role of microbiological processes in them requires the protection of concrete with materials resistant to specific biogenic sulfuric acid aggression. The effective protective materials, in this case, are those that, in addition to acid-proofing materials, have bactericidal properties. Polymer composite materials (PCM) of cold curing based on modified epoxy-resin, resins with dispersed oxides as fillers are widely used in construction. Unique properties and simple technologies make it possible to use them as injection formulations for repair, restoration and restoration of building structures and structures, waterproofing and facing materials, for impregnating, gluing and coating metal, wooden, brick and concrete building structures and parts. In the reconstruction and restoration of sewerage collectors operating under conditions of exposure to liquid biochemically aggressive media with mineral acids and organic substances, particular attention is paid to the permeability of repair materials. Based on the results of the study, PCM compositions were chosen whose estimated lifetime is about 20 years, ensuring reliable protection of the sewage collectors from corrosion.

scholarly journals Predominant role of alpha 4-integrins for distinct steps of lymphoma metastasis.

1996 ◽  
Vol 93 (10) ◽  
pp. 4821-4826 ◽  
Author(s):  
U. Gosslar ◽  
P. Jonas ◽  
A. Luz ◽  
A. Lifka ◽  
D. Naor ◽  
...  
Keyword(s):  
Predominant Role

scholarly journals The role of ammonia in sulfuric acid ion induced nucleation

2008 ◽  
Vol 8 (11) ◽  
pp. 2859-2867 ◽  
Author(s):  
I. K. Ortega ◽  
T. Kurtén ◽  
H. Vehkamäki ◽  
M. Kulmala
Keyword(s):  
Sulfuric Acid ◽  
Quantum Chemical ◽  
Local Minimum ◽  
Good Accuracy ◽  
Energy Surface ◽  
Ground Level ◽  
Computational Effort ◽  
Free Energy Surface ◽  
Large Clusters

Abstract. We have developed a new multi-step strategy for quantum chemical calculations on atmospherically relevant cluster structures that makes calculation for large clusters affordable with a good accuracy-to-computational effort ratio. We have applied this strategy to evaluate the relevance of ternary ion induced nucleation; we have also performed calculations for neutral ternary nucleation for comparison. The results for neutral ternary nucleation agree with previous results, and confirm the important role of ammonia in enhancing the growth of sulfuric acid clusters. On the other hand, we have found that ammonia does not enhance the growth of ionic sulfuric acid clusters. The results also confirm that ion-induced nucleation is a barrierless process at high altitudes, but at ground level there exists a barrier due to the presence of a local minimum on the free energy surface.

scholarly journals Role of intrinsic flaws upon flexural behaviour of a thermoplastic modified epoxy resin

2003 ◽  
Vol 22 (4) ◽  
pp. 429-437 ◽  
Author(s):  
M.I. Giannotti ◽  
M.J. Galante ◽  
P.A. Oyanguren ◽  
C.I. Vallo
Keyword(s):  
Epoxy Resin ◽  
Flexural Behaviour ◽  
Modified Epoxy

The role of acidity profile in the nanotubular growth of polyaniline

2010 ◽  
Vol 64 (1) ◽  
Author(s):  
Elena Konyushenko ◽  
Miroslava Trchová ◽  
Jaroslav Stejskal ◽  
Irina Sapurina
Keyword(s):  
Acetic Acid ◽  
Sulfuric Acid ◽  
Reaction Temperature ◽  
Subsequent Growth ◽  
Subsequent Oxidation ◽  
Ammonium Peroxydisulfate ◽  
Aniline Oligomers ◽  
Positive Effect ◽  
Granular Morphology

AbstractConditions of polyaniline (PANI) nanotubes preparation were analyzed. Aniline was oxidized with ammonium peroxydisulfate in 0.4 M acetic acid. There are two subsequent oxidation steps and the products were collected after each of them. At pH > 3, neutral aniline molecules are oxidized to non-conducting aniline oligomers. These produce templates for the subsequent growth of PANI nanotubes, which takes place preferably at pH 2–3. At pH < 2, granular morphology of the conducting PANI is obtained. High final acidity of the medium should be avoided in the preparation of nanotubes, e.g., by reducing the amount of sulfuric acid which is a by-product. Reduction of the peroxydisulfate-to-aniline mole ratio was tested for this purpose in the present study. Lowering of the reaction temperature from 20°C to −4°C had a positive effect on the formation of nanotubes.

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