Synthesis and Evaluation of Some Triazole Derivatives as Corrosion Inhibitors and Biocides

Three compounds namely; 5-(phenyl)-4H-1,2,4-triazole-3-thiol, 3-(decylthio)-5-phenyl-1H-1,2,4-triazole and 3-(benzylthio)-5-phenyl-1H-1,2,4-triazole) were synthesized. The chemical structure of the prepared compounds was confirmed using FTIR and ¹H-NMR analysis. The compounds were tested as corrosion inhibitors against the corrosion of carbon steel in 1 M HCl using weight loss, polarization and electrochemical impedance methods. The results revealed that these compounds have significant inhibiting effects on the corrosion of carbon steel. Polarization studies showed that the compounds act as mixed-type inhibitors which retard the anodic and the cathodic reactions with a predominant effect towards the cathodic reaction. The prepared compounds were evaluated as antimicrobial agents against sulfate-reducing bacteria using the serial dilution method, which showed good biocidal action.     

Corrosion inhibition and Biocidal effect of some cationic surfactants based on Schiff base

The three cationic surfactants based on Schiff base were laboratory prepared, (E)-decyl-4-[(2-hydroxyethylamino) methyl]-N,N-dimethyl benzenaminium bromide (I), (E)-dodecyl-4-[(2-hydroxyethylamino)methyl]-N,N-dimethyl benzenaminium bromide (II) and (E)-hexadecyl-4-[(2-hydroxyethylamino)methyl]-N,N-dimethyl benzenaminium bromide (III) were evaluated as corrosion inhibitors for carbon steel in acid medium and antimicrobial agents against sulfate reducing bacteria, SRB. Three techniques were used for the corrosion inhibition evaluation, namely; weight loss, polarization and electrochemical impedance. The serial dilution method was used to evaluate the inhibiting effect of these compounds on the sulfate reducing bacteria growth. The results showed that the prepared compounds have good antimicrobial activities against the SRB as well as they have high efficiency as corrosion inhibitors for carbon steel in 1 M HCl.     

Enhancing of Corrosion Inhibition and the Biocidal Effect of Phosphonium Surfactant Compounds for Oil Field Equipment

It is well known that tetra hydroxymethyl phosphonium sulfate (THPS) is commonly used in oil fields as a biocide for sulfate-reducing bacteria (SRB), but it has low corrosion inhibition. In this study, four phosphonium surfactant compounds were synthesized via a coupling reaction between THPS and different fatty acids namely: decanoic, dodecanoic, palmitic and stearic acids to produce the corresponding surfactants. The chemical structure of the synthesized surfactants was confirmed using FTIR and ¹H-NMR spectroscopy. The surface activity of the prepared compounds was determined by surface tension measurements. The critical micelle concentration (CMC) of each surfactant compound was determined. The corrosion inhibition of the synthesized compounds on carbon steel in 0.5 M HCl was studied by weight loss measurements, potentiodynamic and electrochemical impedance spectroscopy. The effect of the inhibitor concentration and hydrophobic chain length on the their efficiency was also studied. It was found that the CMC of each compound depends on its chemical structure. It was also found that the corrosion inhibition efficiency depends on both of concentration and molecular structure of the inhibitors. Polarization curves revealed that the inhibitors used represent mixed-type inhibitors, which hinder the cathodic and anodic parts of the corrosion reaction in acidic media. Adsorption of used inhibitors leads to a reduction in the double layer capacitance and an increase in the charge transfer resistance. Also the biocidal effect of these compounds was enhanced.     

Practical guidelines for a reliability-based design of building water supply systems

Certain complaints about building water supply systems (BWSSs) arise from their oversizing or undersizing. It is essential to improve their efficiency by minimizing their cost and maximizing the benefit accrued from them. This work introduces practical guidelines for BWSSs design, which deal not only with the cost optimization but also with water availability during high demands. A head-dependent analysis function, which takes into consideration the pressure dependency of nodal outflows, is presented. A resilience index, minimum surplus head, and failure index are used to express the capability of BWSSs to overcome peak demand conditions. The proposed approach was applied on a direct BWSS within three identical residential floors at different levels. It was found that, the internal pipes are preferable to have the same diameter while the main riser for each floor must be increased as the height of the floor increases.     

Mesoscale analysis of rubber particle effect on young’s modulus and creep behaviour of crumb rubber concrete

International Journal of Mechanics and Materials in Design - This paper presents a mesoscale model to investigate the rubber particle effect on the mechanical properties of crumb rubber concrete...