5,093 research outputs found

    Diseño de una rectena de onda completa de triple frecuencia

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    Modern communication systems use multifrequency or broadband antennas in order to provide multiple communication services. One of the biggest problems associated to all these systems comes from their batteries life cycle. Nowadays, great efforts are being undertaken in order to harvest energy from as many places as possible. In addition, if the two cycles of the corresponding wave could be used, it would be good in order to increase the RF-DC power conversion. This paper presents a multifrequency and full wave-rectifying antenna for microwave applicatio

    Direct characterization of functional materials by haptenized fluorescent dendrimers for in vitro allergic drug diagnose

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    β-lactams are the most widely drug prescribed against infections, but they are the most commonly reported medication allergy too. A correct diagnosis of these allergic reactions is crucial to avoid rejecting them by other more expensive broad-spectrum antibiotics, with potential risk factors for the development of multiple drug-resistant bacteria. [1] Skin testing is the most consensual approach to diagnose β-lactam allergy, but this in vivo test is not risky free and should be performed under strict hospital surveillance.[2] In vitro testing is not still widely used on account of their low sensitivity. We report the use of already haptenized fluorescent dendrimers [3] to control the preparation of materials for in vitro test, and their verification by testing on patient sera samples. This fluorescent dendrimer is obtained from a dye with two orthogonal functional groups suitable for click chemistry. [4] Acknowledgments: This work was supported by: MINECO CTQ2016-75870P, Andalusian Regional Ministry Health (PI-0250-2016); European Regional Development Fund and “Plan Propio Universidad de Málaga” (UMA-Andalucía-TECH).Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Geospatial analysis of BECCS deployment potential in the U.S.

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    Negative emissions from bioenergy with carbon capture and storage (BECCS) has been identified as a potentially important carbon mitigation technology. To date, much of the technical work and discussion on BECCS have focused on land use change and bioenergy potential, while the CCS components – including capacity, injectivity, and location of potential storage sites – have been overlooked. A geospatial analysis of biomass production and storage sites in the U.S. is conducted to discuss BECCS deployment in the U.S. across a range of biomass production scenarios. U.S. Department of Energy provides national annual biomass production data from 2015 to 2040. Extrapolating the production trends across different yield scenarios to 2100 shows average annual CO2 production from agricultural residue and energy crop of 720-1,220 Mt CO2 yr-1 and cumulative production of 27-47 Gt CO2. Considering that the estimated storage capacity in the U.S. is ~3,000 Gt CO2, absolute storage capacity is not likely to be a constraint on BECCS. However, collocation of high-density biomass (\u3e25 MW per 100×100 km2) and high injection rate storage sites (\u3e5 Mt CO2 yr-1) in 2040 yields biomass CO2 injection potential of 140-360 Mt CO2 yr-1. This represents 9-39% of the total biomass feedstock in the U.S. To achieve a biomass CO2 injection potential greater than 360 Mt CO2 yr-1, transportation networks of either biomass or CO2 will be needed. The geospatial analysis conducted in this study highlights the importance of previously overlooked CCS components in global BECCS assessments and provides a framework for future studies. Please click Additional Files below to see the full abstract

    Effect of scandium triflate on the RAFT copolymerization of methyl acrylate and vinyl acetate controlled by an acid/base “switchable” chain transfer agent

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    Modulation of the activity of an acid/base switchable dithiocarbamate RAFT agent, cyanomethyl (4-fluorophenyl)(pyridin-4-yl)carbamodithioate, with the Lewis acid scandium triflate (Sc(OTf)3) was investigated to examine the ability to deliver improved control over RAFT copolymerizations involving both more-activated and less-activated monomers—specifically the copolymerization of methyl acrylate (MA) and vinyl acetate (VAc). The introduction of either 0.5 or 1 mol equiv of Sc(OTf)3, with respect to RAFT agent, into a RAFT copolymerization of MA and VAc provides substantially improved control resulting in significantly reduced molar mass dispersities (Đ) (∼1.1–1.3) than achieved in its absence (Đ ∼ 1.3–1.4). Furthermore, similar introduction of Sc(OTf)3 into MA homopolymerization mediated by the same RAFT agent also delivered polymers of very low Đ (∼1.15). Sc(OTf)3 was also found to lower the rate of polymerization and alter the copolymerization reactivity ratios for MA and VAc. Increasing the Lewis acid concentration provides enhanced incorporation of the less active monomer, VAc, into the copolymers ([Sc(OTf)3]/[RAFT] = 0, rMA = 4.04, rVAc = 0.032; [Sc(OTf)3]/[RAFT] = 0.5, rMA = 3.08, rVAc = 0.17; [Sc(OTf)3]/[RAFT] = 1, rMA = 2.68, rVAc = 0.62). Carbon nuclear magnetic resonance (13C NMR) and differential scanning calorimetry (DSC) analysis of preparative samples confirm the enhanced VAc incorporation with increased levels of Sc(OTf)3. Importantly the inclusion of Sc(OTf)3 does not deleteriously affect the thiocarbonylthio end-groups of the RAFT polymers, with high end-group fidelity being observed in all copolymerizations
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