Electrochemical and mechanical characteristics of Al-(x)SiC composite fabricated by high energy compaction

Simultaneous compaction and sintering using the energy generated by the underwater explosion is a rapid method that does not have the negative consequences of normal sintering, such as unwanted reactions between components and grain growth. For this reason, this study used the energy from this process to produce Al/SiC composites with different amounts of SiC. As a result, 10, 20, and 30% of SiC powder were added to the Al powder, and then the samples were produced by compression under the influence of an underwater explosion. The results showed that as the amount of SiC increased, the samples' density and the amount of porosity for further agglomeration increased. Microstructural examination by Scanning Electron Microscopy (SEM) confirmed the increase in agglomeration with increasing SiC. Besides, Samples experienced an increase in hardness as the amount of SiC raised. Adding 10% of SiC increased the flexural strength while adding more (20 and 30%) increased the agglomeration resulting in a decrease in strength and elongation. Polarization and impedance spectroscopy (EIS) methods were used to study the samples' electrochemical behavior in a 3.5% NaCl solution. Results showed that the addition of SiC particles up to 10% (wt%) reduces the corrosion density from 9.7 (μA/cm²) to 2.06 (μA/cm²). The Al–10%SiC composite had the lowest corrosion current density compared to 20% and 30% SiC composites. In addition, the polarization resistance of the Nyquist plot for pure Al and Al composite containing 10% SiC was 3965 and 7862, respectively. Therefore, these results showed the beneficial effect of 10% SiC as reinforcing particles on the corrosion behavior of Al composites and thus improved corrosion resistance.     

Synthesis,molecular docking studies,and absorption,distribution, metabolism,and excretion prediction of novel sulfonamide derivatives as antibacterial agents

A series of novel sulfonamide‐amide derivatives were synthesized from 3‐(2,4 dichlorophenylamino)‐3‐oxopropane‐1‐sulfonylchloride and a variety of amines under solvent‐free conditions at room temperature. 3‐(2,4‐dichlorophenylamino)‐3‐oxopropane‐1 sulfonylchloride was synthesized in four steps starting from 2,4‐dichloroaniline and chloropropanoic acid in good yield and purity. The synthesized compounds were screened for their in vitro antibacterial activity against Escherichia coli (ATCC 25922) and Staphylococcus aureus (ATCC 29213). Molecular docking of sulfonamide derivatives into S. aureus tyrosyl‐tRNA synthetase (TyrRS)‐active site was also performed and among these, 5m and 5g tightly fit the active sites that might be inhibitors of TyrRS for further investigations. Also in the silico metabolism profile, drug‐like properties and absorption, distribution, metabolism, excretion and toxicity (ADMET) of the title compounds were calculated by the preADMET server.     

New strategy for the preparation of imidazole derivatives containing thiazole ring via ring opening/coupling/cyclization/decarboxylation cascade

The aim of this work is to investigate the three-component reaction of 6-aminopenicillinic acid, aldehydes and ammonium acetate. The work was used SiO₂-H₂SO₄ as a catalyst to promote the reaction under solvent-free conditions. A series of 5,5-dimethyl-2-(2-aryl-1H-imidazol-5-yl)-2,5-dihydrothiazole derivatives were obtained as the main product by this method.