A cost-effective method to quantify biological surface sediment reworking

We propose a simple and inexpensive method to determine the rate and pattern of surface sediment reworking by benthic organisms. Unlike many existing methods commonly used in bioturbation studies, which usually require sediment sampling, our approach is fully non-destructive and is well suited for investigating non-cohesive fine sediments in streams and rivers. Optical tracer (e.g., luminophores or coloured sand) disappearance or appearance is assessed through time based on optical quantification of surfaces occupied by tracers. Data are used to calculate surface sediment reworking (SSR) coefficients depicting bioturbation intensities. Using this method, we evaluated reworking activity of stream organisms (three benthic invertebrates and a fish) in laboratory microcosms mimicking pool habitats or directly in the field within arenas set in depositional zones. Our method was sensitive enough to measure SSR as low as 0.2 cm2.d-1, such as triggered by intermediate density (774 m-2) of Gammarus fossarum (Amphipoda) in microcosms. In contrast, complex invertebrate community in the field and a fish (Barbatula barabatula) in laboratory microcosms were found to yield to excessively high SSR (>60 cm2.d-1). Lastly, we suggest that images acquired during experiments can be used for qualitative evaluation of species-specific effects on sediment distribution

Self-assembly of mechanically interlocked and threaded rings: a HREELS and XPS study of thiol-functionalised catenane and rotaxane molecules on Au(111)

Thiol-functionalised catenane and rotaxane thin films were investigated in order to understand the self-assembly of such complex molecules on Au(111). Adsorption from the liquid phase at 300 K leads to the formation of overlayers without long-range order, as evidenced by high-resolution electron energy-loss spectroscopy (HREELS). As expected for thiol adsorption, the sulfur 2p binding energies determined by X-ray photoelectron spectroscopy (XPS) are consistent with the formation of thiolate surface intermediates. The properties of these films are explored as a function of annealing. Changes in vibrational spectra such as the emergence of a AuMO band and variations in core-level binding energies and intensities reveal molecular rearrangement due to partial desorption. In addition, based on coherent domain sizes estimated by the angular width of the elastic beam intensity, annealing promotes long-range order within the adlayers.

Local magnetism in rare-earth metals encapsulated in fullerenes

Local magnetic properties of rare-earth (RE) atoms encapsulated in fullerenes have been characterized using x-ray magnetic circular dichroism and x-ray absorption spectroscopy (XAS). The orbital and spin contributions of the magnetic moment have been determined through sum rules and theoretical model calculations, and have been found to be highly reduced compared to those of the corresponding free RE3+ ions. Crystal-field and hybridization effects have been investigated by the way of calculations to simulate the effect of the carbon cage on the RE; both hypotheses have reproduced the experimental spectra resulting also in a significant reduction of the orbital and spin moments. While isotropic XAS spectra have confirmed a roughly trivalent state for the RE metals, a back electron transfer from the cage to the metal has been quantified. A paramagnetic coupling has been found between the metal centers from 6 K to 300 K.

Of other (energy) spaces: protected areas and everyday landscapes of energy in the southern Italian region of Alta Murgia

The text is a chapter in the book Renewable Energies and European Landscapes: Lessons from Southern European Cases. The book provides timely, multidisciplinary cross-national comparison of the institutional and social processes through which renewable energy landscapes have emerged in Southern Europe (Spain, France, Italy and Portugal). On the basis of case studies in these countries, it analyzes the way in which and the extent to which the development of renewable energies has affected landscape forms and whether or not it has contributed to a reformulation of landscape practices and values in these countries. Landscape is conceived broadly, as a material, social, political and historical process embedded into the local realm, going beyond aesthetic. The chapter presents a case study in the southern Italian region of Puglia (Apulia), the rural area of Alta Murgia, which is partly included within the perimeter of the first National Rural Park in Italy (Alta Murgia National Park). The study focuses on the process of PV power development in this agricultural area since the first Italian feed-in tariff system came into force (2005–2007). The purpose of the study is to explore the impacts of the political forces embodied in the planning process of these renewable energy projects. This goal is achieved by considering not only the impacts on the socioeconomic development of the whole area over the last decade but also those on the landscape features and values that sustain and enable local socioeconomic development. National and regional renewable energy policies, on the one hand, and the National Park Plan and Regulations, on the other hand, have engendered dramatically different consequences for the agricultural lands located inside and outside the perimeter of the protected area. The argument developed in the chapter is that these two radically different approaches to the process of energy project planning ultimately reinforce the physical and symbolic gap existing between so-called particularly worthy landscapes and ordinary everyday landscapes (of energy). It is argued that the process of PV plant planning and development in the areas surrounding the Park has been essentially dominated and led by a sort of “site counter-logic.” This ultimately resulted in a “counter-site logic.” In the conclusion, the chapter emphasizes the potential for the planning process of green energy projects to act as a laboratory for experimenting with a new integrated approach to energy provisioning, as both a conceptual frame and a biophysical phenomenon

landscapes of energies, a perspective on the energy transition

internationalInternational audienceThis chapter discusses the way in which cross-national comparison shall be approached. We assume that energy landscapes emerge at the crossroad of RE technology development and changes in current landscapes. We successively discuss different frameworks for approaching technology development and landscape change, before turning to the recent literature about landscape and renewable energy development. We conclude that cross-national comparison of landscapes of energies should be attentive to the type of landscape tradition at work in each country and account for the fact that the development of renewable energy endows these traditions with a renewed existence. Depending on the extent and the focus of the conflicts or controversies raised around RE projects, the method and focus of the analysis shall differ. © Springer Science+Business Media Dordrecht 2015

Core level photoemission of rotaxanes: A summary on binding energies

Several rotaxanes were studied by XPS in the form of thin films or monolayers on gold substrates. Here we report a database of photoemission spectra of the C 1s, N 1s and F 1s core levels. Binding energy ranges are summarized, classifying the core levels according to the chemical groups that form part of the rotaxanes.