The esterification reaction of ethyl alcohol and acetic acid catalyzed by the ion exchange resin, Amberlyst 15, was investigated. The experimental study was implemented in an isothermal batch reactor. Catalyst loading, initial molar ratio, mixing time and temperature as being the most effective parameters, were extensively studied and discussed. A maximum final conversion of 75% was obtained at 70°C, acid to ethyl alcohol mole ratio of 1/2 and 10 g catalyst loading. Kinetic of the reaction was correlated with Langmuir-Hanshelwood model (LHM). The total rate constant and the adsorption equilibrium of water as a function of the temperature was calculated. The activation energies were found to be as 113876.9 and -49474.95 KJ per Kmol of ac

In this study, derivatives of polyvinyl alcohol (PVA) grafted with phthalic anhydride (PhA) and dyes were prepared to produce polymeric materials of PVA-g-PhA, PVA-g-PhA-anthocyanin, PVA-g-PhA-bromophenol blue, and PVA-g-PhAthymol blue. The materials were characterised by FTIR and 1 H NMR spectroscopies. The crystallinity of the polymers was evaluated with powder X-ray difraction, and the thermal stability by thermogravimetric analysis (TGA). The synthetic procedure for the polymeric materials entailed the formation of esters. The FTIR spectra of the polymers confrmed their formation since the ester carbonyl group stretch was observed at approximately 1691–1716  cm−1 in each material. NMR spectroscopy confrmed the addition of t

The objective of this review was to describe the COVID-19 complications after recovery.

Self-repairing technology based on micro-capsules is an efficient solution for repairing cracked cementitious composites. Self-repairing based on microcapsules begins with the occurrence of cracks and develops by releasing self-repairing factors in the cracks located in concrete. Based on previous comprehensive studies, this paper provides an overview of various repairing factors and investigative methodologies. There has recently been a lack of consensus on the most efficient criteria for assessing self-repairing based on microcapsules and the smart solutions for improving capsule survival ratios during mixing. The most commonly utilized self-repairing efficiency assessment indicators are mechanical resistance and durab

Heterocyclic compounds serve as crucial structural elements in the field of pharmaceutical medicinal chemistry. The five-membered heterocyclic nucleus of 1,3,4-oxadiazole occupies a distinctive position within medicinal chemistry and plays a vital role in the development of anticancer agents. Recognized as a significant pharmacophore for approximately 85 years, 1,3,4-oxadiazole is in high demand across various biological and chemical disciplines. This small and straightforward nucleus is found in numerous compounds that are the focus of research concerning their properties, synthesis, derivatives, and pharmacological activities, including anticancer, antibacterial, antimalarial, anti-inflammatory, antidepressant, analgesic, and antiviral