A series of long-tail alkyl ethanolamine analogs containing amide-, urea-, and thiourea moieties was synthesized and the behavior of the corresponding monolayers was assessed on the Langmuir−Pockels trough combined with grazing incidence X-ray diffraction experiments and complemented by computer simulations. All compounds form stable monolayers at the soft air/water interface. The phase behavior is dominated by strong intermolecular headgroup hydrogen bond networks. While the amide analog forms well-defined monolayer structures, the stronger hydrogen bonds in the urea analogs lead to the formation of small three-dimensional crystallites already during spreading due to concentration fluctuations. The hydrogen bonds in the thiourea case form a two-dimensional network, which ruptures temporarily during compression and is recovered in a self-healing process, while in the urea clusters the hydrogen bonds form a more planar framework with gliding planes keeping the structure intact during compression. Because the thiourea analogs are able to self-heal after rupture, such compounds could have interesting properties as tight, ordered, and self-healing monolayers.
Este trabajo pretende dar a conocer en qué medida la satisfacción del alumnado con la docencia recibida en la Universidad de Oviedo se puede considerar dependiente del éxito obtenido en la correspondiente asignatura. Los resultados muestran que los estudiantes están más satisfechos con la docencia en aquellas asignaturas que tienen mayor porcentaje de éxito si bien, en las asignaturas optativas la satisfacción decrece con los valores de éxito más altos. La expectativa, definida por el ajuste entre estudiantes matriculados y aprobados, influye en la satisfacción con la enseñanza recibida.
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.