An experimental study of damage characteristics at bond of RC after microwave heating

With an increase in urban construction waste, and in order to find an effective method of microwave-assisted mechanical RC regeneration, thermal damage characteristics of the interfacial bond between steel rebar and concrete after different microwave irradiations are analysed in this paper. The results show that, with an increase in microwave power, the overall failure mode of the specimen changes from splitting failure to pull-out failure. Bond slip curves and the corresponding fitting equations were obtained at various levels of microwave irradiation. By analysing characteristic points of the curve, 3500W was determined as a reasonable irradiation power.

Synthesis and Biological Evaluation of New Chromenes and Chromeno[2,3-d] pyrimidines

ABSTRACT A simple and efficient approach has been developed to synthesise novel and functionalised 5H-chromeno[2,3-d] pyrimidines derivatives (4a-h). This approach entails treating 2-amino-3-cyano-4H-chromenes (3a-h) with formamidine acetate under microwave irradiations and solvent-free conditions. All structures of new compounds obtained in this study were characterised by IR, MS, 1H and 13C NMR analysis. Additionally, the synthesised compounds were investigated for their antibacterial and antioxidant potential. Compounds 3b, 3c, 3e, 4c and 4e showed significant activities. Keywords: 5H-chromeno[2,3-d] pyrimidine; 4H-chromene; solvent-free conditions; antioxidant activity; antibacterial activity

Synthesis of Medicinally Important Quinazolines and Their Derivatives: A Review

The study of biodynamic heterosystems has proved to be the most attractive and useful for the development of potential drugs with superior properties and works effectively for the treatment of a variety of diseases, including pandemic ones. Out of the thousand biodynamic heterosystems, the quinazoline heterosystem is one that exhibits wide-ranging biological and pharmacological properties. Synthesis of potential medicinal material is comparatively challenging and needed enough time for clinical trials, testing, permissions for concerned authorities, production and supply. Therefore, researchers usually focused on novel methods incorporated with a high yield of previously approved chemical compounds. This present review article has focused on the synthesis of medicinally important quinazolines and their derivatives, which produce reaction products in less time with high yields, including more attention with eco-friendly green synthesis approaches incorporating multicomponent reactions (MCR), ionic liquids and microwave irradiations.