188 research outputs found

    Benzofuran-fused Phosphole: Synthesis, Electronic, and Electroluminescence Properties

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    International audienceA synthetic route to novel benzofuran-fused phosphole derivatives 3-5 is described. These compounds showed optical and electrochemical properties that differ from their benzothiophene analog. Preliminary results show that 4 can be used as an emitter in OLEDs, illustrating the potential of these new compounds for opto-electronic applications

    Comparing hydrological responses across catchments using a new soil water content metric

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    Soil water content (SWC) is a fundamental variable involved in several hydrological processes governing catchment functioning. Comparative analysis of hydrological processes in different catchments based on SWC data is therefore beneficial to infer driving factors of catchment response. Here, we explored the use of high-temporal resolution SWC data in three forested catchments (2.4–60 ha) in different European climates to characterize hydrological responses during wet and dry conditions. The investigated systems include Ressi, Italy, with a humid temperate climate, Weierbach, Luxembourg, with a semi-oceanic climate, and Can Vila, Spain, with a Mediterranean climate. We introduced a new SWC metric defined as the difference between seasonal mean SWC at a relatively shallow and a deep soil layer. The difference is classified in three distinct states: similar SWC between the two layers, higher SWC in the deeper layer, and higher SWC in the shallow layer. In the most humid site, Ressi, we frequently found similar SWC at the two soil depths which was associated with high runoff ratios. Despite similar precipitation amounts in Can Vila and Weierbach, SWC patterns were very different in both catchments. In Weierbach, SWC was similar across the entire soil profile during wet conditions, whereas evaporation of shallow water resulted in higher SWC in the deep soil layer during dry conditions. This led to high runoff ratios during wet conditions and low runoff ratios during dry conditions. In Can Vila, SWC was consistently higher in the deeper layer compared to the shallow layer, irrespective of the season, suggesting an important role of hydraulic redistribution and vertical water movement in this site. Our approach provides an easy and useful method to assess differences in hydrological behaviour solely based on SWC data. As similar datasets are increasingly collected and available, this opens the possibility for further analyses and comparisons in sites around the globe with contrasted physiographic and climate characteristics.C. Segura acknowledges a Fulbright Fellowship that supported her stay at the University of Florence, Italy and the National Science Foundation Award No. 1943574. The Weierbach datasets have been collected in the framework of the Doctoral Training Unit HYDRO-CSI (Innovative methodologies for unravelling hydrological, chemical, and biological interactions across multiple scales), funded by the National Research Fund of Luxembourg (grant PRIDE15/10623093). Data collection in Ressi catchment was supported by the projects “Ecohydrological Dynamics and Water Pathways in Forested Catchments” (Bando Starting Grants 2015, Fondazione Cassa di Risparmio di Padova e Rovigo), the project “SILVA-Water fluxes between soil, vegetation and atmosphere: a comparative analysis in two Italian forested catchments” (funded by Premio Florisa Melone 2018, assigned by the Italian Hydrological Society), the Italian MIUR Project (PRIN 2017) “WATer mixing in the critical ZONe: observations and predictions under environmental changes-WATZON” (code: 2017SL7ABC), and the RETURN Extended Partnership, receiving funding from the European Union Next-GenerationEU (National Recovery and Resilience Plan – NRRP, Mission 4, Component 2, Investment 1.3 – D.D. 1243 2/8/2022, PE0000005). J. Latron and L. Pfister contributions have been supported by the RHYSOTTO (PID2019-106583RB-I00) and WARMed (PID2022-141868NB-I00) projects, both funded by the Spanish Ministry of Science and Innovation (Ministerio de Ciencia e Inovación, Agencia Estatal de Investigación). J. Latron and L. Pfister also acknowledge the collaboration of Gisel Bertran and Elisenda Sánchez during field work and data collection. The results of this study were discussed within the COST Action: “WATSON” CA19120. We also thank the constructive reviews from Nitin Singh and an anonymous reviewer.Peer reviewe

    Teaching Story without Struggle: Using Graded Readers and Their Audio Packs in the EFL Classroom

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    In recent years the support for extensive reading (ER) in English as a second or foreign language (ESL/EFL) programs has been compelling. When practicing extensive reading, the learner reads a wide variety of texts for pleasure and achieves a general understanding of the content while deciphering unknown words through context. This approach contrasts with intensive reading, a more traditional approach based on a slow, careful reading of a text, with goals of complete comprehension and the identification of specific details and information

    A Standardized Morpho-Functional Classification of the Planet’s Humipedons

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    It was time to take stock. We modified the humipedon classification key published in 2018 to make it easier and more practical. This morpho-functional taxonomy of the topsoil (humipedon) was only available in English; we also translated it into French and Italian. A standardized morphofunctional classification of humipedons (roughly the top 30–40 cm of soil: organic and organomineral surface horizons) would allow for a better understanding of the functioning of the soil ecosystem. This paper provides the founding principles of the classification of humipedon into humus systems and forms. With the recognition of a few diagnostic horizons, all humus systems can be determined. The humus forms that make up these humus systems are revealed by measuring the thicknesses of the diagnostic horizons. In the final part of the article, several figures represent the screenshots of a mobile phone or tablet application that allows for a fast recall of the diagnostic elements of the classification in the field. The article attempts to promote a standardized classification of humipedons for a global and shared management of soil at planet level

    A standardized morpho-functional classification of the planet’s humipedons

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    It was time to take stock. We modified the humipedon classification key published in 2018 to make it easier and more practical. This morpho-functional taxonomy of the topsoil (humipedon) was only available in English; we also translated it into French and Italian. A standardized morphofunctional classification of humipedons (roughly the top 30–40 cm of soil: organic and organomineral surface horizons) would allow for a better understanding of the functioning of the soil ecosystem. This paper provides the founding principles of the classification of humipedon into humus systems and forms. With the recognition of a few diagnostic horizons, all humus systems can be determined. The humus forms that make up these humus systems are revealed by measuring the thicknesses of the diagnostic horizons. In the final part of the article, several figures represent the screenshots of a mobile phone or tablet application that allows for a fast recall of the diagnostic elements of the classification in the field. The article attempts to promote a standardized classification of humipedons for a global and shared management of soil at planet level

    Inter-laboratory comparison of cryogenic water extraction systems for stable isotope analysis of soil water

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    For more than two decades, research groups in hydrology, ecology, soil science, and biogeochemistry have performed cryogenic water extractions (CWEs) for the analysis of ή2H and ή18O of soil water. Recent studies have shown that extraction conditions (time, temperature, and vacuum) along with physicochemical soil properties may affect extracted soil water isotope composition. Here we present results from the first worldwide round robin laboratory intercomparison. We test the null hypothesis that, with identical soils, standards, extraction protocols, and isotope analyses, cryogenic extractions across all laboratories are identical. Two standard soils with different physicochemical characteristics along with deionized (DI) reference water of known isotopic composition were shipped to 16 participating laboratories. Participants oven-dried and rewetted the soils to 8 and 20 % gravimetric water content (WC), using the deionized reference water. One batch of soil samples was extracted via predefined extraction conditions (time, temperature, and vacuum) identical to all laboratories; the second batch was extracted via conditions considered routine in the respective laboratory. All extracted water samples were analyzed for ή18O and ή2H by the lead laboratory (Global Institute for Water Security, GIWS, Saskatoon, Canada) using both a laser and an isotope ratio mass spectrometer (OA-ICOS and IRMS, respectively). We rejected the null hypothesis. Our results showed large differences in retrieved isotopic signatures among participating laboratories linked to soil type and soil water content with mean differences compared to the reference water ranging from +18.1 to −108.4 ‰ for ή2H and +11.8 to −14.9 ‰ for ή18O across all laboratories. In addition, differences were observed between OA-ICOS and IRMS isotope data. These were related to spectral interferences during OA-ICOS analysis that are especially problematic for the clayey loam soils used. While the types of cryogenic extraction lab construction varied from manifold systems to single chambers, no clear trends between system construction, applied extraction conditions, and extraction results were found. Rather, observed differences in the isotope data were influenced by interactions between multiple factors (soil type and properties, soil water content, system setup, extraction efficiency, extraction system leaks, and each lab's internal accuracy). Our results question the usefulness of cryogenic extraction as a standard for water extraction since results are not comparable across laboratories. This suggests that defining any sort of standard extraction procedure applicable across laboratories is challenging. Laboratories might have to establish calibration functions for their specific extraction system for each natural soil type, individually.</p
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