Photocatalysis| Sulfonated dibenzazepines | Radical reactions | Ugi reaction | AnnulationA new method to access sulfonated dibenz[b,e]azepines via visible-light photoredox catalysis is described. Employing inexpensive and commercially available sulfonyl chlorides to form the sulfonyl radicals enables the alkyne addition reaction followed by a 7-membered radical cyclization step to furnish sulfonated dibenzazepines. In addition, an Ugi-type multicomponent reaction (MCR) for the synthesis of o-aminophenylacetylene derivatives can also be used as a rapid substrate synthesis method for the cascade radical cyclization protocol to obtain a series of highly functionalized sulfonylated dibenzazepines, which undoubtedly greatly simplifies the synthetic steps of the dibenzazepine compounds that are important core structures in pharmaceuticals.
The paper presents an overview of a finite element approach for the analysis of the thermohygro-mechanical-hydration behaviour of concrete structures. The thermo-hygro component considers the mass balance equation of moisture as well as the enthalpy balance equation, and uses two primary variables, namely the capillary pressure and temperature. Heat of hydration is simulated using the approach of Schlinder and Folliard. The basic mechanical model simulates directional cracking, rough crack closure and crushing using a plastic-damage-contact approach. Hydration dependency is introduced into the mechanical constitutive model. The material data from the Concrack benchmark (CEOS.fr,2013) are considered with the model. This includes data on adiabatic temperature changes during curing, changing elastic properties during curing, shrinkage and creep. The model, as implemented in the finite element program LUSAS, is used to analyse the Concrack benchmark beam RL1. Particular attention is paid to crack openings and the difference between predicted crack openings from analyses with and without time dependent effects. It is concluded that ignoring time dependent effects can result in a significant underestimate of crack openings in the working load range.
Wave-induced liquefaction is one of the main factors influence the stability of marine structures. However, the investigation on this phenomenon is complicated as the dynamic interaction between soil, pore fluid and the structure is closely coupled. In order to obtain a better understanding of the wave-induced response around the circular caisson founded in the seabed, three dimensional numerical analyses have been performed using the 3D finite element program DYNE3WAC in order to investigate the wave-induced response around the circular caisson.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.