Molecular organization of n-cyanobiphenyl liquid crystals on a molybdenite surface

The alignement and anchoring of liquid crystals on solid surfaces is a key problem for modern device technology that until now has been treated empirically, but that can now be tackled by atomistic computer simulations. Molecular dynamics (MD) simulations were used in this thesis work to study two films of 7 and 8 n-alkyl-4’cyanobiphenyl (7CB and 8CB) liquid crystals , with a thickness of 15 nm, confined between two (001) surfaces of MoS2 (molybdenite). The isotropic and nematic phases of both liquid crystals were simulated, and the resulting structures characterized structurally. A new force field was designed to model the interactions between the liquid crystal (LC) molecules and the surface of molybdenite, while an accurate force field developed previously was used to model the 7CB and 8CB molecules. The results show that the (001) molybdenite surface induces a planar orientation in both the liquid crystals. For the nematic phase of 8CB, one of the two solid/LC interfaces is composed of a first layer of molecules aligned parallel to the surface, followed by a second layer of molecules aligned perpendicular to the surface (also called, homeotropic). The effect of the surface appears to be local in nature as it is confined to the first 15 Angström of the LC film. Conversely, for the nematic phase of 7CB, a planar ordering is established into the LC film. The LC molecules at the interface with the molybdenite appear to align preferentially their alkyl chains toward the solid substrate. The resulting tilt angle of molecules was found to be in good agreement with experimental measurements available in literature. Despite the fact that the MD simulations spanned a time range of more than 100 ns, the nematic phases of both 7CB and 8CB were found not to be completely formed. In order to confirm the findings presented in this thesis, we propose to extend the current study.

Una panoramica sulle agenzie di traduzione: caratteristiche, tipologie e flussi di lavoro

Over the last decades the need for translation and interpreting services has increased thanks to globalization and to the progress made in the technology field. However, the organizations which provide these services, the so-called translation agencies or translation companies, are still underrated and, in some cases, virtually unknown to those people who do not belong to the translation market. The present work aims to answer all the most common questions about these companies by describing in as much detail as possible all their aspects, mechanisms, workflows and characteristics. Chapter one introduces translation agencies outlining, in the first place, some of their main definitions and classifications. Particular attention is also devoted to the translation market, to the main trade associations in the field, to the quality standards adopted and to the important role played by social media for the success of translation agencies. Chapter two starts with a theoretical introduction to the concept of “organization” and an examination of the main types of teams commonly adopted in companies, i.e. virtual and traditional. This introduction is then followed by an analysis of the typical workflows taking place in translation agencies, the main professionals involved (such as Project Managers, translators and reviewers) and their essential competences. Finally, chapter three presents a comparison between a traditional translation agency, i.e., Going Green Translations, characterized by a physical office and internal collaborators, and a more innovative translation agency, Qabiria, which on the contrary relies on a completely decentralized team. The interviews have allowed me to highlight similarities and differences as well as advantages and disadvantages of these agencies and their teams. The chapter concludes with a personal commentary on what has emerged from the comparison, and on the future of translation companies.