118 research outputs found

    Enhanced activity of carbon-supported Pd-Pt catalysts in the hydrodechlorination of dichloromethane

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    Monometallic and bimetallic catalysts with different proportions of Pd and Pt prepared by co-impregnation on activated carbon have been deeply characterized by inductively coupled plasma-mass spectroscopy, temperature-programmed reduction, 77K N2 adsorption-desorption, CO chemisorption, transmission electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. They have been tested in the gas-phase hydrodechlorination of dichloromethane (DCM) at atmospheric pressure, reaction temperatures of 150-200°C, and a space-time of 0.6kghmol-1. The presence of Pd and Pt in the catalysts produces a synergistic effect observed in terms of dichloromethane conversion and overall dechlorination, especially when both metals are in similar proportions. The results from catalysts characterization suggest that the enhanced activity is due to a significant decrease of the metallic particles size and an optimum ratio of electro-deficient to zero-valent species in the bimetallic catalysts. The catalyst with 0.90wt.% of Pt and 0.50wt.% of Pd yielded the best results. Under intensified conditions, viz. 250°C and 1.73kghmol-1, 100% DCM conversion and 98.6% overall dechlorination were obtained. This catalyst had most of its metallic particles within the range of 0.5-1nmThe authors gratefully acknowledge financial support from the Spanish Ministerio de Economía y Competitividad through the project CTM2011-28352. M. Martín Martínez acknowledges the Spanish Ministerio de Ciencia e Innovación and the European Social Fund for her research grant (BES 2009-016802

    Stereovideo youtube channel: short educational videos for the on-line learning of the the stereographic projection technique in Structural Geology

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    Stereovideo channel https://www.youtube.com/user/geostereovideo) is a YouTube channel of short educational videos (<5 min) focused on learning the handling of the stereographic projection technique applied to Structural Geology (also to Engineering Geology). This type of videos aims to reinforce the traditional classroom lessons with the use of communication technologies resources. Such a einforcing facilitates the possibility to deepen more on conceptual aspects once the students dominate the representation tool helping them to develop their own critical thinking skills. After three years of being launched on-line (on 2014), we analyze the broadcast and acceptance of the channel by the academic community. For this purpose we have taken into account two different sources: (1) the analytics tool from YouTube (subscriptions, views, countries, comments from the users, type of device for viewing), and (2) our own survey among users (students and teachers) to get their opinion about the videos. By January, 2017 (date of sending of this abstract), the channel has a total of 650 subscriptions, with more than 85,000 views all around the world, mainly in Spanish speaking countries (as the videos are in Spanish). The main devices for viewing the videos are PCs, but is noteworthy the use of smart phones and tablets. The video users, both students and teachers, value this type of content positively

    Stereovideo youtube channel: short educational videos for the on-line learning of the the stereographic projection technique in Structural Geology

    Get PDF
    Stereovideo channel https://www.youtube.com/user/geostereovideo) is a YouTube channel of short educational videos (<5 min) focused on learning the handling of the stereographic projection technique applied to Structural Geology (also to Engineering Geology). This type of videos aims to reinforce the traditional classroom lessons with the use of communication technologies resources. Such a einforcing facilitates the possibility to deepen more on conceptual aspects once the students dominate the representation tool helping them to develop their own critical thinking skills. After three years of being launched on-line (on 2014), we analyze the broadcast and acceptance of the channel by the academic community. For this purpose we have taken into account two different sources: (1) the analytics tool from YouTube (subscriptions, views, countries, comments from the users, type of device for viewing), and (2) our own survey among users (students and teachers) to get their opinion about the videos. By January, 2017 (date of sending of this abstract), the channel has a total of 650 subscriptions, with more than 85,000 views all around the world, mainly in Spanish speaking countries (as the videos are in Spanish). The main devices for viewing the videos are PCs, but is noteworthy the use of smart phones and tablets. The video users, both students and teachers, value this type of content positively

    Compilation of parameterized seismogenic sources in Iberia for the SHARE European-scale seismic source model.

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    Abstract: SHARE (Seismic Hazard Harmonization in Europe) is an EC-funded project (FP7) that aims to evaluate European seismic hazards using an integrated, standardized approach. In the context of SHARE, we are compiling a fully-parameterized active fault database for Iberia and the nearby offshore region. The principal goal of this initiative is for fault sources in the Iberian region to be represented in SHARE and incorporated into the source model that will be used to produce seismic hazard maps at the European scale. The SHARE project relies heavily on input from many regional experts throughout the Euro-Mediterranean region. At the SHARE regional meeting for Iberia, the 2010 Working Group on Iberian Seismogenic Sources (WGISS) was established; these researchers are contributing to this large effort by providing their data to the Iberian regional integrators in a standardized format. The development of the SHARE Iberian active fault database is occurring in parallel with IBERFAULT, another ongoing effort to compile a database of active faults in the Iberian region. The SHARE Iberian active fault database synthesizes a wide range of geological and geophysical observations on active seismogenic sources, and incorporates existing compilations (e.g., Cabral, 1995; Silva et al., 2008), original data contributed directly from researchers, data compiled from the literature, parameters estimated using empirical and analytical relationships, and, where necessary, parameters derived using expert judgment. The Iberian seismogenic source model derived for SHARE will be the first regional-scale source model for Iberia that includes fault data and follows an internationally standardized approach (Basili et al., 2008; 2009). This model can be used in both seismic hazard and risk analyses and will be appropriate for use in Iberian- and European-scale assessments

    The state of the Martian climate

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    60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes

    Using modeling tools for implementing feasible land use and nature conservation governance systems in small islands e The Pico Island (Azores) case-study

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    The present study deals with the development of systematic conservation planning as management instrument in small oceanic islands, ensuring open systems of governance, and able to integrate an informed and involved participation of the stakeholders. Marxan software was used to define management areas according a set of alternative land use scenarios considering different conservation and management paradigms. Modeled conservation zones were interpreted and compared with the existing protected areas allowing more fused information for future trade-outs and stakeholder's involvement. The results, allowing the identification of Target Management Units (TMU) based on the consideration of different development scenarios proved to be consistent with a feasible development of evaluation approaches able to support sound governance systems. Moreover, the detailed geographic identification of TMU seems to be able to support participated policies towards a more sustainable management of the entire islan

    Global wealth disparities drive adherence to COVID-safe pathways in head and neck cancer surgery

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    American palm ethnomedicine: A meta-analysis

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    <p>Abstract</p> <p>Background</p> <p>Many recent papers have documented the phytochemical and pharmacological bases for the use of palms (<it>Arecaceae</it>) in ethnomedicine. Early publications were based almost entirely on interviews that solicited local knowledge. More recently, ethnobotanically guided searches for new medicinal plants have proven more successful than random sampling for identifying plants that contain biodynamic ingredients. However, limited laboratory time and the high cost of clinical trials make it difficult to test all potential medicinal plants in the search for new drug candidates. The purpose of this study was to summarize and analyze previous studies on the medicinal uses of American palms in order to narrow down the search for new palm-derived medicines.</p> <p>Methods</p> <p>Relevant literature was surveyed and data was extracted and organized into medicinal use categories. We focused on more recent literature than that considered in a review published 25 years ago. We included phytochemical and pharmacological research that explored the importance of American palms in ethnomedicine.</p> <p>Results</p> <p>Of 730 species of American palms, we found evidence that 106 species had known medicinal uses, ranging from treatments for diabetes and leishmaniasis to prostatic hyperplasia. Thus, the number of American palm species with known uses had increased from 48 to 106 over the last quarter of a century. Furthermore, the pharmacological bases for many of the effects are now understood.</p> <p>Conclusions</p> <p>Palms are important in American ethnomedicine. Some, like <it>Serenoa repens </it>and <it>Roystonea regia</it>, are the sources of drugs that have been approved for medicinal uses. In contrast, recent ethnopharmacological studies suggested that many of the reported uses of several other palms do not appear to have a strong physiological basis. This study has provided a useful assessment of the ethnobotanical and pharmacological data available on palms.</p

    Challenges in assessing and managing multi-hazard risks: A European stakeholders perspective

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    The latest evidence suggests that multi-hazards and their interrelationships (e.g., triggering, compound, and consecutive hazards) are becoming more frequent across Europe, underlying a need for resilience building by moving from single-hazard-focused to multi-hazard risk assessment and management. Although significant advancements were made in our understanding of these events, mainstream practice is still focused on risks due to single hazards (e.g., flooding, earthquakes, droughts), with a limited understanding of the stakeholder needs on the ground. To overcome this limitation, this paper sets out to understand the challenges for moving towards multi-hazard risk management through the perspective of European stakeholders. Based on five workshops across different European pilots (Danube Region, Veneto Region, Scandinavia, North Sea, and Canary Islands) and an expert workshop, we identify five prime challenges: i) governance, ii) knowledge of multi-hazards and multi-risks, iii) existing approaches to disaster risk management, iv) translation of science to policy and practice, and v) lack of data. These challenges are inherently linked and cannot be tackled in isolation with path dependency posing a significant hurdle in transitioning from single- to multi-hazard risk management. Going forward, we identify promising approaches for overcoming some of the challenges, including emerging approaches for multi-hazard characterisation, a common understanding of terminology, and a comprehensive framework for guiding multi-hazard risk assessment and management. We argue for a need to think beyond natural hazards and include other threats in creating a comprehensive overview of multi-hazard risks, as well as promoting thinking of multi-hazard risk reduction in the context of larger development goals

    Outcomes from elective colorectal cancer surgery during the SARS-CoV-2 pandemic

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    This study aimed to describe the change in surgical practice and the impact of SARS-CoV-2 on mortality after surgical resection of colorectal cancer during the initial phases of the SARS-CoV-2 pandemic
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