In situ atomic force microscopy (AFM) allowed us to investigate the evolution at the early stages of the growth of organic thin films. An ultrahigh-vacuum atomic force microscope, integrated with a Knudsen effusion cell for the sublimation of α-sexithiophene (6T), continuously scans the same region during the deposition of sublimed molecules on native silicon oxide as a function of the substrate temperature. Noncontact AFM images acquired sequentially provide snapshots of the time evolution of the film morphology that is monitored up to the deposition of five monolayers. At all substrate temperatures, a Stranski−Krastanov growth mode of organic films is observed: the first two monolayers grow layer-by-layer (two-dimensional2D), then films evolve into islands (three-dimensional3D). Despite the apparent similarity, we find an anomalous dynamic scaling characterized by the abrupt change of the growth exponent β vs substrate temperature. This novel transition, induced by the substrate temperature, is ascribed to the morphological transition from ziggurat islands to large terraces. The analysis of the evolution of the root-mean-square (RMS) roughness based on the distributed growth model underlines the role of down-hill mass transport for the growth of the first two monolayers, transport that is progressively hindered for the next monolayers.
The EAMPA project is a research programme focused on the implementation of an environmental accounting system for all the 29 Italian Marine Protected Areas (MPAs). The main goal of such a system is the calculation of the ecological and economic value of the MPAs, with particular reference to the ecosystem services generated in each protected area. Environmental and economic costs as well as the impacts related to human activities in the MPAs will be also assessed. Finally, an overall balance and the assessment of net benefits will be calculated. To reach this goal, a multicriteria environmental accounting system will be implemented following a standardized protocol of assessment. The outcomes of the project will be managed through an operational WebGIS platform capable of spreading user-friendly information to local managers, policy makers, and other stakeholders. The environmental accounting system will be structured to be updatable over time, thus representing a useful tool for the management of the MPAs in the years to come. Moreover, the research programme represents a unique opportunity to establish a collaborative network among all Italian MPAs. Finally, the outcomes of the project will be also functional to other important and timely processes dealing with the study and protection of European marine ecosystems, such as the Marine Strategy Framework Directive.
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.