9 research outputs found

    Altimetry for the future: Building on 25 years of progress

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    In 2018 we celebrated 25 years of development of radar altimetry, and the progress achieved by this methodology in the fields of global and coastal oceanography, hydrology, geodesy and cryospheric sciences. Many symbolic major events have celebrated these developments, e.g., in Venice, Italy, the 15th (2006) and 20th (2012) years of progress and more recently, in 2018, in Ponta Delgada, Portugal, 25 Years of Progress in Radar Altimetry. On this latter occasion it was decided to collect contributions of scientists, engineers and managers involved in the worldwide altimetry community to depict the state of altimetry and propose recommendations for the altimetry of the future. This paper summarizes contributions and recommendations that were collected and provides guidance for future mission design, research activities, and sustainable operational radar altimetry data exploitation. Recommendations provided are fundamental for optimizing further scientific and operational advances of oceanographic observations by altimetry, including requirements for spatial and temporal resolution of altimetric measurements, their accuracy and continuity. There are also new challenges and new openings mentioned in the paper that are particularly crucial for observations at higher latitudes, for coastal oceanography, for cryospheric studies and for hydrology. The paper starts with a general introduction followed by a section on Earth System Science including Ocean Dynamics, Sea Level, the Coastal Ocean, Hydrology, the Cryosphere and Polar Oceans and the ‘‘Green” Ocean, extending the frontier from biogeochemistry to marine ecology. Applications are described in a subsequent section, which covers Operational Oceanography, Weather, Hurricane Wave and Wind Forecasting, Climate projection. Instruments’ development and satellite missions’ evolutions are described in a fourth section. A fifth section covers the key observations that altimeters provide and their potential complements, from other Earth observation measurements to in situ data. Section 6 identifies the data and methods and provides some accuracy and resolution requirements for the wet tropospheric correction, the orbit and other geodetic requirements, the Mean Sea Surface, Geoid and Mean Dynamic Topography, Calibration and Validation, data accuracy, data access and handling (including the DUACS system). Section 7 brings a transversal view on scales, integration, artificial intelligence, and capacity building (education and training). Section 8 reviews the programmatic issues followed by a conclusion

    Altimetry for the future: building on 25 years of progress

    Get PDF
    In 2018 we celebrated 25 years of development of radar altimetry, and the progress achieved by this methodology in the fields of global and coastal oceanography, hydrology, geodesy and cryospheric sciences. Many symbolic major events have celebrated these developments, e.g., in Venice, Italy, the 15th (2006) and 20th (2012) years of progress and more recently, in 2018, in Ponta Delgada, Portugal, 25 Years of Progress in Radar Altimetry. On this latter occasion it was decided to collect contributions of scientists, engineers and managers involved in the worldwide altimetry community to depict the state of altimetry and propose recommendations for the altimetry of the future. This paper summarizes contributions and recommendations that were collected and provides guidance for future mission design, research activities, and sustainable operational radar altimetry data exploitation. Recommendations provided are fundamental for optimizing further scientific and operational advances of oceanographic observations by altimetry, including requirements for spatial and temporal resolution of altimetric measurements, their accuracy and continuity. There are also new challenges and new openings mentioned in the paper that are particularly crucial for observations at higher latitudes, for coastal oceanography, for cryospheric studies and for hydrology. The paper starts with a general introduction followed by a section on Earth System Science including Ocean Dynamics, Sea Level, the Coastal Ocean, Hydrology, the Cryosphere and Polar Oceans and the “Green” Ocean, extending the frontier from biogeochemistry to marine ecology. Applications are described in a subsequent section, which covers Operational Oceanography, Weather, Hurricane Wave and Wind Forecasting, Climate projection. Instruments’ development and satellite missions’ evolutions are described in a fourth section. A fifth section covers the key observations that altimeters provide and their potential complements, from other Earth observation measurements to in situ data. Section 6 identifies the data and methods and provides some accuracy and resolution requirements for the wet tropospheric correction, the orbit and other geodetic requirements, the Mean Sea Surface, Geoid and Mean Dynamic Topography, Calibration and Validation, data accuracy, data access and handling (including the DUACS system). Section 7 brings a transversal view on scales, integration, artificial intelligence, and capacity building (education and training). Section 8 reviews the programmatic issues followed by a conclusion

    Effect of particle size on LiMnPO4 cathodes

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    LiMnPO4 was synthesized using a sol–gel method and tested as a cathode material for lithium ion batteries. After calcination at temperatures between 520 and 600 ◩C, primary particle sizes in the range of 140–220 nm were achieved. Subsequent dry ball milling reduced the primary particle diameters from 130 to 90 nm, depending on time of ball milling. Reversible capacities of 156 mAh g−1 at C/100 and 134 mAh g−1 at C/10 were measured. At 92% and 79% of the theoretical values, respectively, these are the highest values reported to date for this material. At faster charging rates, the electrochemical performance was found to be improved when smaller LiMnPO4 particles were used

    High-performance, nano-structured LiMnPO4 synthesized via a polyol method

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    A novel polyol synthesis was adopted to synthesize nano-structured LiMnPO4. This route yields well-crystallized nanoparticles with platelet morphology that are only similar to 30 nm thick oriented in the b direction. The obtained material presented a good rate behavior and a very long cyclic life both at room temperature (RT) and 50 degrees C. The sample exhibited a specific capacity of 145 mAh g(-1) at C/20, 141 mAh g(-1) at C/10 rate and 113 mAh g(-1) 1C rate. This represents is the highest performance results reported to date for this material. The high rate performance is ascribed to the platelet shape of the LiMnPO4 as it minimizes the paths for Li diffusion. At elevated temperature (50 degrees C) this material demonstrated improved reversible capacity of 159 mAh g(-1) at C/10 and 138 at 1C. The electrode retained 95% of its capacity, over 200 cycles, both at RT and 50 degrees C. This electrochemical stability is ascribed to the structural strength of the P-O bond and the stability of the electrolyte-LiMnPO4 interface. It allows us to conclude that the impact of a possible Jahn-Teller distortion is not critical. These excellent results clarified some ambiguities on LiMnPO4 as cathode materials. and demonstrate its promise for its practical application. (C) 2008 Elsevier B.V. All rights reserved

    Improving the Electrochemical Activity of LiMnPO4 Via Mn-Site Substitution

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    HPL SA report the modification of the electrochemical performance of lithium manganese phosphate (LiMnPO4) via Mn-site bivalent substitution. Manganese (10%) is substituted with iron, nickel, magnesium, or zinc. These substituents are shown via an X-ray to form solid solutions. The choice of substituent is demonstrated to have a strong influence on the electrochemical performance. The optimum performance improvement was achieved when 10% of Fe is substituted. This is ascribed to a smaller crystallite and a higher electronic conductivity observed in this material: Presumably Fe plays a role in hindering the crystallite growth and in increasing the carrier's transportation. Electronic structures were calculated by density function theory to understand the different influences of substitute cations

    Improving the Electrochemical Activity of LiMnPO4 Via Mn-Site Substitution

    No full text
    HPL SA report the modification of the electrochemical performance of lithium manganese phosphate (LiMnPO4) via Mn-site bivalent substitution. Manganese (10%) is substituted with iron, nickel, magnesium, or zinc. These substituents are shown via an X-ray to form solid solutions. The choice of substituent is demonstrated to have a strong influence on the electrochemical performance. The optimum performance improvement was achieved when 10% of Fe is substituted. This is ascribed to a smaller crystallite and a higher electronic conductivity observed in this material: Presumably Fe plays a role in hindering the crystallite growth and in increasing the carrier's transportation. Electronic structures were calculated by density function theory to understand the different influences of substitute cations

    Patients with metastatic melanoma receiving anticancer drugs: changes in overall survival, 2010-2017

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    International audienceImmune checkpoint inhibitors (ICI) and targeted therapies have profoundly altered the management of several cancers over the past decade. Metastatic melanoma has been at the forefront of these changes. We provide here a nationwide overview and an assessment of changes in survival in France. We included 10,936 patients receiving a systemic treatment for metastatic cutaneous melanoma between 2010 and 2017 using the French national health insurance database (SNDS, ex-SNIIRAM). Over the study period, there was a doubling of the number of new patients receiving a systemic treatment. Cytotoxic chemotherapy was progressively replaced by targeted therapy and ICI. Patients having initiated a first-line treatment since June 2015 gained 46% OS compared to those initiating treatment before 2012. 24-month OS rose from 21% to 44%. We provide real-world evidence for the improvement of OS in the past decade among patients with metastatic melanoma. Although the characteristics of the patients treated can vary across periods, this type of exhaustive real-world data provides evidence from broader populations than those included in clinical trials
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