2,304 research outputs found

    Handling magnetic and structural properties of EuMnO3 thin films by the combined effect of Lu doping and substrate strain

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    This work aims to understand the alterations induced by film/substrate lattice mismatch in structure, lattice dynamics and magnetic response of orthorhombic Eu1-xLuxMnO3 thin films within the range 0 ≤ x ≤ 0.4, when compared to results reported for ceramics with analogous composition. Thin films, which have been deposited onto Pt/Ti/SiO2/Si(100) oriented substrates via chemical method, exhibit noteworthy modifications in the magnetic ordering properties and, contrary to ceramics, do not show any sharp phase transition to the paramagnetic state. This reveals an induced ferromagnetic response in the films which is stable up to 100 K. X-ray diffraction and Raman spectroscopy measurements have been performed to identify the mechanically compressive state induced by the substrate and Lu doping. This facilitates insight into the magnetoelastic coupling effect in these films which is driven by alterations in electronic orbital overlapping and the associated antiferromagnetic superexchange interactions.publishe

    Optimal generic energy storage system offering in day-ahead electricity markets

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    This paper models the offers and bids of a generic storage system in an electricity market through stochastic mixed integer linear programming. The objective function aims at maximizing the profit from buying or selling energy for a general storage system. Some parameters such as storage system efficiency, losses of the energy stored and marginal costs are parameterized to evaluate the offers and bids. Market prices are forecasted for 24 hours using AR, MA and ARIMA time series models. The problem is tested for a case study, analyzing the behaviour of the offers and bids. Also, the results obtained are studied and relevant conclusions are presented.Es la versión aceptada del documento. Se puede consultar la versión final en el DOI 10.1109/PTC.2015.723244

    Nail - Patella Syndrome

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    A Síndrome Unha-Rótula ou Nail-Patella Syndrome (OMIN 161200) (Osteo-Onicodisplasia Hereditária), descrita pela primeira vez por Chatelain em 1820, é uma síndrome polimalformativa rara que afecta tecidos de origem ecto e mesodérmica. É condição hereditária, transmitida como traço autossómico dominante, tendo o gene responsável sido identificado (9q34) e caracterizado como codificando uma proteína que desempenha papel crítico no desenvolvimento padronizado dorso-ventral dos tecidos dos membros. Clinicamente, caracteriza-se por aplasia ou hipoplasia das unhas e rótulas, pela presença de exostoses nos ilíacos (“cornos ilíacos”), anomalias pigmentares na íris e nefropatia. As alterações ungueais, habitualmente presentes à nascença, são altamente evocadoras e permitem um diagnóstico precoce, como tal prevenindo o desenvolvimento ulterior de importantes limitações osteo-esqueléticas ou de insuficiência renal. É apresentado caso clínico de jovem de 4 anos, do sexo masculino, eurocaucasiano, com instabilidade na marcha e rótulas ausentes, uma perturbação do desenvolvimento preenchendo critérios para a Síndrome de Asperger e anomalias ungueais congénitas. Neste caso são dignos de registo o contraste nítido entre a extensão das alterações dermatológicas, a discreta expressão das anomalias ortopédicas e a inexistência de compromisso renal. Efectivamente, não apenas não tinha alterações renais ou auditivas como - para além da ausência das rótulas, de uma clinodactilia do 5º dedo das mãos e de uma ligeira discromia iridiana - nenhumas outras alterações foram detectadas numa criança com um óbvio atraso do desenvolvimento estato-ponderal.info:eu-repo/semantics/publishedVersio

    Spatial and temporal variability of soil CO2 flux in sugarcane green harvest systems

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    The sugarcane green harvest system, characterized by mechanized harvesting and the absence of crop burning, affects soil quality by increasing crop residue on the soil surface after harvest; thus, it contributes to improving the physical, chemical, and microbiological properties and influences the soil carbon content and CO2 flux (FCO2). This study aimed to evaluate the spatial and temporal variability of soil FCO2 in sugarcane green harvest systems. The experiment was conducted in two areas of sugarcane in São Paulo, Brazil: the first had a 5-year history of sugarcane green harvest (SG-5) and the second had a longer history of 10 years (SG-10). The temporal FCO2 were evaluated in the dry and rainy periods, and spatial variability in the dry period, and related to soil chemical and physical properties, including organic C porosity, bulk density, soil penetration resistance, mean weight diameter of soil aggregates, clay, P, S, Ca, Mg and Fe. The temporal variability indicated no differences between the dry and rainy periods in SG-10, while in SG-5 soil moisture was increased by 33 % in the rainy period. The spatial variability indicated a different pattern from the temporal one, where FCO2 in SG-10 was correlated with soil temperature, air-filled pore space, total porosity, soil moisture, and the Ca and Mg contents; in the SG-5 area, FCO2 was correlated with soil mean weight diameter of soil aggregates and the sulfur content.4

    Enhancement of resistivity and magnetization of Bi1-xLaxFe1-yMnyO3 ceramics by composition optimization

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    This work aims at studying the effect of La and Mn substituents on the structural, electrical and magnetic properties of Bi1-xLaxFe1-yMnyO3 (0≤x≤0.30; 0≤y≤0.20) at room temperature, in order to find out the optimal compositions that provide both high resistivity and remnant magnetization. The analysis of the XRD patterns and Raman spectra suggest a progressive transition from a rhombohedral for x0.20. Moreover, we observe satellite peaks associated with an incommensurate modulated (IM) orthorhombic structure for x≥0.15 with y = 0, and x = 0.20 with y = 0.10. We were able to achieve a decrease by several orders of magnitude of the leakage current density and the emergence of a weak ferromagnetic response in the range of compositions 0.10<x≤0.3 and 0<y<0.1. These improved physical properties are a consequence of the absence of secondary phases and the breaking of the spiral cycloid spin structure. In particular, the compositions within 0.18≤x≤0.30 and 0.01<y<0.05 with IM orthorhombic structure exhibit the lowest conductivity and highest remnant magnetization. The outcome of this work suggests an alternative route to enhance multiferroic properties of BiFeO3, with simultaneous La (0.10≤x≤0.30) and moderate Mn (0.01<y<0.1) substitution.publishe

    Soil management of sugarcane fields affecting CO2 fluxes

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    The harvesting system of green sugarcane, characterized by mechanized harvesting and no crop burning, affects soil quality by increasing the remaining straw left on the soil surface after harvesting, thus, contributing to the improvement of physical, chemical, and microbiological soil attributes, influencing CO2 fluxes. This study aimed to evaluate CO2 fluxes and their relation to soil properties in sugarcane crops under different harvesting managements: burned (B), Green harvesting for 5 years (G-5) and Green harvesting for ten years (G-10). For this, a 1 ha sampling grid with 30 points was installed in each area, all located in the Northeast of São Paulo State, Brazil. In each point, CO2 fluxes were measured and the soil was sampled to analyze the microbial biomass, physical (soil moisture and temperature, mean weight diameter, bulk density, clay, macroporosity and microporosity) and chemical characterization (pH, organic C, base saturation and P). The CO2 fluxes were divided into four quantitative criteria: high, moderate, low and very low from the Statistical Division (mean, first quartile, median and third quartile) and the other data were classified according this criterion. The Principal Component Analysis (PCA) was used to identify the main soil attributes that influence CO2 fluxes. The results showed that G-10 CO2 fluxes were 28 and 41 % higher than those in the G-5 and B treatments, respectively. The PCA analysis showed that macroporosity was the main soil attribute that influenced the high CO2 fluxes

    Spectral optical monitoring of 3C390.3 in 1995-2007: I. Light curves and flux variation of the continuum and broad lines

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    Here we present the results of the long-term (1995-2007) spectral monitoring of the broad line radio galaxy \object{3C~390.3}, a well known AGN with the double peaked broad emission lines, usually assumed to be emitted from an accretion disk. To explore dimensions and structure of the BLR, we analyze the light curves of the broad Hα\alpha and Hβ\beta line fluxes and the continuum flux. In order to find changes in the BLR, we analyze the Hα\alpha and Hβ\beta line profiles, as well as the change in the line profiles during the monitoring period. First we try to find a periodicity in the continuum and Hβ\beta light curves, finding that there is a good chance for quasi-periodical oscillations. Using the line shapes and their characteristics (as e.g. peaks separation and their intensity ratio, or FWHM) of broad Hβ\beta and Hα\alpha lines, we discuss the structure of the BLR. Also, we cross-correlate the continuum flux with Hβ\beta and Hα\alpha lines to find dimensions of the BLR. We found that during the monitoring period the broad emission component of the Hα\alpha and Hβ\beta lines, and the continuum flux varied by a factor of \approx 4-5. Also, we detected different structure in the line profiles of Hα\alpha and Hβ\beta. It seems that an additional central component is present and superposed to the disk emission. In the period of high activity (after 2002), Hβ\beta became broader than Hα\alpha and red wing of Hβ\beta was higher than the one of Hα\alpha. We found time lags of \sim95 days between the continuum and Hβ\beta flux, and about 120 days between the continuum and Hα\alpha flux. Variation in the line profiles, as well as correlation between the line and continuum flux during the monitoring period is in the favor of the disk origin of the broad lines with the possible contribution of some additional region and/or some kind of perturbation in the disk.Comment: 32 pages, accepted to A&A, typos correcte

    Importância prognóstica do alelo CYP2C19*2 após uma síndrome coronária aguda: dados de um centro nacional

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    BACKGROUND: Clopidogrel requires oxidation dependent on the cytochrome P450 enzyme 2C19 (CYP2C19) to form its active metabolite. The importance of loss-of-function alleles (particularly CYP2C19*2, 681G>A) in poor platelet response to clopidogrel is well recognized. OBJECTIVE: To investigate the prevalence and prognostic impact of the CYP2C19*2 allele in a local acute coronary syndrome (ACS) population. METHODS: We performed a prospective, longitudinal study of 95 patients admitted for an ACS between March and October 2009 to a single coronary care unit. Patients aged under 75 who survived hospital stay and for whom clopidogrel was prescribed were included. At discharge, CYP2C19 was genotyped using a commercially available kit. Patients were divided into two groups: Group A (non-carriers, normal metabolizers, CYP2C19*1/*1), n=69; and Group B (carriers, slow metabolizers, CYP2C19*2/*1 or *2/*2), n=26. The primary endpoint was a combined outcome of cardiovascular death, non-fatal myocardial infarction or re-admission for unstable angina; median follow-up was 136.0 (79.0-188.0) days. RESULTS: The median age of the population was 62.0 (51.0-68.0) years, and 83.2% were male. The CYP2C19*2 (A) allele had a frequency of 14.2%. There were no differences between the groups with respect to demographic data or history of cardiovascular disease. Coronary anatomy, left ventricular ejection fraction and renal function were also similar. The groups were also homogenous with respect to GRACE risk score (118.0 (95.0-136.5) vs. 115.0 (96.0-133.0), p=0.68), medical treatment and percutaneous revascularization during hospital stay. Event-free survival was higher for Group A (94.0% vs. 75.0%, log-rank p=0.010). Three readmissions for MI were documented, all in the slow metabolizers group. CONCLUSION: In our ACS population, the CYP2C19*2 allele was a medium-term prognostic marker
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