1,210 research outputs found

    Structural, photoluminescent properties and Judd-Ofelt analysis of Eu3+-activated CaF2 nanocubes

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    Eu3+-doped CaF2 nanocubes with variable europium concentration, [Eu3+] = 0, 0.6, 1.3, 1.7, 2.2 and 5.4 mol%, have been synthesized by a direct precipitation route. It has been found that, within this concentration range, the nanoparticles present the fluoride-type crystalline structure and the characteristic cubic shape of CaF2 crystals. The nanoparticle size follows a log-normal distribution with a mean value decreasing with the Eu3+ content. Rietveld refinement has been performed to calculate the lattice parameter and crystallite size. Eu3+ concentration affects both parameters giving rise to an increase in the lattice parameter and a reduction of crystallite size. The luminescent properties of Eu3+ ions in these nanostructures have been investigated under CW and pulsed excitation. A Judd-Ofelt analysis, as function of the Eu3+ content, has been performed to determine the transition probabilities, radiative lifetimes and branching ratios of the 5D0 emitting level. It was found that and Judd-Ofelt intensity parameters are dependent on the doping level, showing an evolution that indicates a decrease in the Eu3+ site local symmetry with increasing Eu3+ concentration. Finally, it has been observed that the characteristic luminescence decay time of the 5D0 manifold is reduced with increasing Eu3+ concentration. This effect is partially due to an increase of radiative transition probability, associated with a reduction in the local symmetry of the lanthanide ions, and also to the occurrence of concentration quenching effectsThis work has been partially supported by Ministerio de Economía y Competitividad and Ministerio de Ciencia, Innovación y Universidades under projects MAT2016-75716-2-2-R and RTI2018- 101020-B-I00

    Ammonia emissions from a soil amended with urea and inhibitor of urease activity in a Mediterranean area

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    Urea and ammonium-based fertilisers are nowadays one of the most important sources of ammonia (NH3) emissions to the atmosphere in Europe. However, little is known about NH3 volatilisation in Mediterranean areas. The aim of the present study was the quantification of NH3 emissions by using the Integrated Horizontal Flux (IHF) method after application of urea with the urease inhibitor N-(n-butyl) thiophosphorie triamide (NBPT) to a semiarid agricultural soil. The field experiment was carried out at "La Poveda" field station in Madrid on a sunflower crop in spring 2006. Urea and a mixture of urea and the inhibitor (0.14%) were surfaee-applied by hand at a rate of 170 kg N ha"' to eircular plots (diam. 40 m). The soil was irrigated with 10 mm of water just after the applieation of urea to dissolve and incorporate it onto the first layer of soil. There were three peaks in the NH3 flux over the duration of the measurement period (36 d). The first peak was associated to irrigation and the others to rainfall events. The total NH3 emission during the whole experiment (36 days) was 17.3 ±5.5kgNH3-N ha"1 in the ease of urea treated soils and 10.0 ± 4.5 kg NHrN ha"' where NBPT was ineluded with the urea

    Visually-Guided Manipulation Techniques for Robotic Autonomous Underwater Panel Interventions

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    The long term of this ongoing research has to do with increasing the autonomy levels for underwater intervention missions. Bearing in mind that the speci c mission to face has been the intervention on a panel, in this paper some results in di erent development stages are presented by using the real mechatronics and the panel mockup. Furthermore, some details are highlighted describing two methodologies implemented for the required visually-guided manipulation algorithms, and also a roadmap explaining the di erent testbeds used for experimental validation, in increasing complexity order, are presented. It is worth mentioning that the aforementioned results would be impossible without previous generated know-how for both, the complete developed mechatronics for the autonomous underwater vehicle for intervention, and the required 3D simulation tool. In summary, thanks to the implemented approach, the intervention system is able to control the way in which the gripper approximates and manipulates the two panel devices (i.e. a valve and a connector) in autonomous manner and, results in di erent scenarios demonstrate the reliability and feasibility of this autonomous intervention system in water tank and pool conditions.This work was partly supported by Spanish Ministry of Research and Innovation DPI2011-27977-C03 (TRITON Project) and DPI2014-57746-C3 (MERBOTS Project), by Foundation Caixa Castell o-Bancaixa and Universitat Jaume I grant PID2010-12, by Universitat Jaume I PhD grants PREDOC/2012/47 and PREDOC/2013/46, and by Generalitat Valenciana PhD grant ACIF/2014/298. We would like also to acknowledge the support of our partners inside the Spanish Coordinated Projects TRITON and MERBOTS: Universitat de les Illes Balears, UIB (subprojects VISUAL2 and SUPERION) and Universitat de Girona, UdG (subprojects COMAROB and ARCHROV)

    Does Socioeconomic Status Influence the Risk of Subclinical Atherosclerosis?: A Mediation Model

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    BACKGROUND: Socioeconomic status (SES)-education, income level, and occupation-is associated with cardiovascular risk. OBJECTIVES: This study aimed to investigate the association between SES and subclinical atherosclerosis and the potential mechanisms involved. METHODS: SES, lifestyle habits (smoking, dietary patterns, physical activity, and hours of sleep), traditional risk factors, and subclinical atherosclerosis extent were prospectively assessed in 4,025 individuals aged 40 to 54 years without known cardiovascular disease enrolled in the PESA (Progression of Early Subclinical Atherosclerosis) study. After factors associated with atherosclerosis were identified, a multiple mediation model was created to quantify the effect of SES on subclinical atherosclerosis as explained by lifestyle behaviors. RESULTS: Although education level was significantly associated with the presence of atherosclerosis, no differences were found according to income level in this population. Participants with lower education presented with a higher risk of generalized atherosclerosis than those with higher education (odds ratio: 1.46; 95% confidence interval: 1.15 to 1.85; p = 0.002). Lifestyle behaviors associated with both education level and atherosclerosis extent were: smoking status, number of cigarettes/day, and dietary pattern, which explained 70.5% of the effect of SES on atherosclerosis. Of these, tobacco habit (smoking status 35% and number of cigarettes/day 32%) accounted for most of the explained differences between groups, whereas dietary pattern did not remain a significant mediator in the multiple mediation model. CONCLUSIONS: Despite the relative economic homogeneity of the cohort, lower education level is associated with increased subclinical atherosclerosis, mainly mediated by the higher and more frequent tobacco consumption. Smoking cessation programs are still needed, particularly in populations with lower education level.The PESA study is cofunded equally by the Fundación Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Spain; and Banco Santander, Madrid, Spain. The study also receives funding from the Institute of Health Carlos III (PI15/02019) and the European Regional Development Fund. The CNIC is supported by the Ministry of Economy, Industry and Competitiveness and the Pro CNIC Foundation, and is a Severo Ochoa Center of Excellence (SEV-2015-0505). This work is part of a project that has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No707642; and from the American Heart Association under grantnumber14SFRN20490315. Dr. Bueno has received research funding from the Instituto de Salud Carlos III (PIE16/00021), AstraZeneca, Bristol-Myers Squibb, Janssen, and Novartis; has received consulting fees from Abbott, AstraZeneca, Bayer, Bristol-Myers Squibb-Pfizer, and Novartis; and has received speaking fees or support for attending scientific meetings from AstraZeneca, Bayer, Bristol-Myers Squibb-Pfizer, Ferrer, Novartis, Servier, and MEDSCAPE-the heart.org.S

    Animal feeding strategies to reduce N2O and NH3 emission from surface-applied pig slurry to a grassland soil.

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    It is estimated that N losses from fertilized crops range between 50-70%, depending on management practices, climate and soil conditions. Ammonia (NH3) emissions following land application of animal manures give rise to a significant proportion of the total NH3 emissions from agricultural sources

    Performance of Magnetic-Superconductor Non-Contact Harmonic Drive for Cryogenic Space Applications

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    Harmonic drives are profusely used in aerospace mainly because of their compactness and large reduction ratio. However, their use in cryogenic environments is still a challenge. Lubrication and fatigue are non-trivial issues under these conditions. The objective of the Magnetic-Superconductor Cryogenic Non-contact Harmonic Drive (MAGDRIVE) project, funded by the EU Space FP7, is to design, build, and test a new concept of MAGDRIVE. Non-contact interactions among magnets, soft magnetic materials, and superconductors are efficiently used to provide a high reduction ratio gear that smoothly and naturally operates at cryogenic environments. The limiting elements of conventional harmonic drives (teeth, flexspline, and ball bearings) are substituted by contactless mechanical components (magnetic gear and superconducting magnetic bearings). The absence of contact between moving parts prevents wear, lubricants are no longer required, and the operational lifetime is greatly increased. This is the first mechanical reducer in mechanical engineering history without any contact between moving parts. In this paper, the test results of a −1:20 inverse reduction ratio MAGDRIVE prototype are reported. In these tests, successful operation at 40 K and 10−3 Pa was demonstrated for more than 1.5 million input cycles. A maximum torque of 3 N·m and an efficiency of 80% were demonstrated. The maximum tested input speed was 3000 rpm, six times the previous existing record for harmonic drives at cryogenic temperature

    Causes of cetacean stranding and death on the Catalonian coast (western Mediterranean Sea), 2012-2019

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    The causes of cetacean stranding and death along the Catalan coast between 2012 and 2019 were systematically investigated. Necropsies and detailed pathological investigations were performed on 89 well-preserved stranded cetaceans, including 72 striped dolphins Stenella coeruleoalba, 9 Risso's dolphins Grampus griseus, 5 bottlenose dolphins Tursiops truncatus, 1 common dolphin Delphinus delphis, 1 Cuvier's beaked whale Ziphius cavirostris and 1 fin whale Balaenoptera physalus. The cause of death was determined for 89.9% of the stranded cetaceans. Fisheries interaction was the most frequent cause of death in striped dolphins (27.8%) and bottlenose dolphins (60%). Cetacean morbillivirus (CeMV) was detected on the Catalan coast from 2016 to 2017, causing systemic disease and death in 8 of the 72 (11.1%) striped dolphins. Chronic CeMV infection of the central nervous system was observed from 2018-2019 in a further 5 striped dolphins. Thus, acute and chronic CeMV disease caused mortality in 18% of striped dolphins and 14.6% of all 89 cetaceans. Brucella ceti was isolated in 6 striped dolphins and 1 bottlenose dolphin with typical brucellosis lesions and in 1 striped dolphin with systemic CeMV. Sinusitis due to severe infestation by the nematode parasite Crassicauda grampicola caused the death of 4 out of 6 adult Risso's dolphins. Maternal separation, in some cases complicated with septicemia, was a frequent cause of death in 13 of 14 calves. Other less common causes of death were encephalomalacia of unknown origin, septicemia, peritonitis due to gastric perforation by parasites and hepatitis caused by Sarcocystis spp.info:eu-repo/semantics/publishedVersio

    Luces y sombras de la Guía Europea ESC-2021 de Prevención de la Enfermedad Cardiovascular en la Práctica Clínica

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    General practitioners see in their consultation a a significant number of patients at high vascular risk (VR). The European Guidelines for Cardiovascular Disease Prevention (2021) recommend a new risk classification and intervention strategies on on vascular risk factors (RF), with the aim of providing a shared decision-making recommendations between professionals and patients. In this document we present a critical analysis of these guidelines, offering possible solutions that can be implemented in Primary Care. It should be noted that there are positive aspects (lights) such as that the SCORE2 (from forty to sixty-nine years) and SCORE2-OP models (from seventy to eighty-nine years) are based on more current cohorts and measure cardiovascular risk in a more accurately manner. In addition, it is proposed to differentiate different risk thresholds according to age-groups. For sake of practicality, cardiovascular risk can be estimated using different websites with the new computer models. However, among the negative aspects (shadows), it seems to be add complexity implementing nine subgroups of subjects according to their age or level of risk, with a defined thresholds that could cause a substantial increase in the potential number of subjects susceptible to treatment without a clear evidence that supports it. In addition, two-step RF interventions could delay achievement of therapeutic goals, especially in very high-risk patients, diabetics, or patients with cardiovascular disease. Given these limitations, in this document we propose practical recommendations in order to simplify and facilitate the implementation of the guideline in primary care.Los médicos de familia atienden un importante número de pacientes con alto riesgo vascular (RV). Las Guías Europeas de Prevención Cardiovascular (2021) proponen una nueva clasificación del riesgo y estrategias de intervención sobre los factores de riesgo (FRV), orientada a la toma de decisiones compartidas entre profesionales y pacientes. En el presente trabajo realizamos un análisis crítico de dichas guías, ofreciendo posibles soluciones prácticas para la Atención Primaria. Son destacables aspectos positivos (luces) que los modelos de RV SCORE2 (entre cuarenta y sesenta y nueve años) y SCORE2-OP (entre setenta y ochenta y nueve años) se basan en cohortes más actuales y miden con mayor exactitud y discriminación dicho riesgo. Además, se propone actuar diferenciadamente sobre el riesgo según la edad. Pragmáticamente, se presentan nuevos modelos informáticos para calcular el riesgo. Sin embargo, entre los aspectos negativos (sombras), parece colegirse una mayor dificultad de implementación al proponerse nueve subgrupos de sujetos según su edad o nivel de riesgo, con un dintel definitorio de alto RV subjetivo que podría ocasionar un incremento sustancial en el número de sujetos susceptibles de tratar sin una discriminación objetiva que lo sustente. Además, las intervenciones sobre los FRV en dos pasos podrían retrasar la consecución de objetivos terapéuticos, sobre todo en pacientes de muy alto riesgo, diabéticos o con enfermedad cardiovascular. Ante las dificultades que plantea la valoración del riesgo, proponemos unificar criterios y simplificar los mensajes claves para hacer unas guías más atractivas y que realmente ayuden a los profesionales de Atención Primaria en su práctica habitual
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