906 research outputs found

    Anti-de Sitter curvature radius constrained by quasars in brane-world scenarios

    Full text link
    This paper is intended to investigate the luminosity due to accretion of gas in supermassive black holes (SMBHs) in the center of quasars, using a brane-world scenario naturally endowed with extra dimensions, whereon theories formulated introduce corrections in the field equations at high energies. SMBHs possess the necessary highly energetic environment for the introduction of these corrections, which are shown to produce small deviations in all SMBH properties and, consequentely, corrections in the accretion theory that supports quasars radiative processes. The radiative flux observed from quasars indicates these deviations, from which the magnitude of the AdS5_5 bulk curvature radius, and consequently the extra dimension compactification radius is estimated.Comment: 11 pages, RevTeX, Eq.(2) and (3) expanded, and comments thereon update

    Core-shell rare-earth-doped nanostructures in biomedicine

    Get PDF
    The current status of the use of core-shell rare-earth-doped nanoparticles in biomedical applications is reviewed in detail. The different core-shell rare-earth-doped nanoparticles developed so far are described and the most relevant examples of their application in imaging, sensing, and therapy are summarized. In addition, the advantages and disadvantages they present are discussed. Finally, a critical opinion of their potential application in real life biomedicine is givenThis work has been partially supported by the Ministerio de Economía y Competitividad de España (MINECO) (MAT2016-75362-C3-1-R), by the Instituto de Salud Carlos III (PI16/ 00812), by the Comunidad Autónoma de Madrid (B2017/ BMD-3867RENIM-CM), by the European Comission (NanoTBTech), and co-financed by European Structural and Investment Fund. This work has also been partially supported by COST action CM1403. L. L. P. thanks the Universidad Autónoma de Madrid for the “Formación de personal investi-gador (FPI-UAM)” program. P. R. S. thanks MINECO and the Fondo Social Europeo (FSE) for the “Promoción del talento y su Empleabilidad en I+D+i” statal program (BES-2014-069410). D. H. O. is grateful to the Instituto de Salud Carlos III for a Sara Borrell Fellowship (CD17/00210

    Ultrasound measures of Nellore cattle supplemented of yeast and probiotic in the north of Mato Grosso.

    Get PDF
    The search for better results on the performance and carcass traits of cattle under grazing has required efforts in the elaboration of diets that satisfy them both the producer and the consumer; therefore, the supplementation of grazing cattle is one of the main strategies for the intensification of systems. It is important to identify the effects of dietary supplementation on bovine growth through ultrasound imaging, which in addition to being an indication of the carcass composition allows estimation of the thickness of subcutaneous fat, as it helps to protect the carcass cold shortening. The objective of this study was to evaluate bovine carcass alterations, by means of ultrasound images, finished with pasture with additives supplementation. Twenty-eight noncastrated males of the Nellore breed were randomly divided into four supplementation groups (Group 1 = Urea; Group 2 = Urea + Optygen; Group 3 = Group 2 + Yeasts; and Group 4 = Group 3 + Probiotic). The experimental area used was of eight hectares, with Brachiaria brizantha cv. BRS Piatã, subdivided into four pens. The experiment lasted for 98 days, with 14 initial days of adaptation and the remainder subdivided into three sub-periods of 28 days, with the performance of ultrasonic readings at the end of each sub-period. For the measurement of the rib eye area (REA) and the subcutaneous fat thickness of loin (SFTL), images were taken between the 12th and 13th ribs, transversal to Musculus longissimus thoracis. For fat thickness of the rump (P8), the images were taken at the junction between M. gluteos medium and M biceps femoris, with the use of vegetable oil as an acoustic coupling. Data were analyzed using the Statistical Analyzes System software in a completely randomized design. The animal of Group 3 showed high (P 0.05) was observed among treatments, with general means of 5.53 mm in the end period. It can be concluded that the use of yeasts as an additive in the supplementation of cattle to pasture presented beneficial effects on carcass composition

    Characterization of Soybean Cultivars for Biodiesel Production

    Full text link
    Due to environmental issues involving the polluting gasesemission, Brazil has adopted the policy of using oil and biodiesel. For biodiesel production, the main raw material used in Brazil is soybean oil. The development of the numerous genotypes of this culture has always considered quantitative aspects. The objective was to qualitatively characterize 12 soybean cultivars for biodiesel production. The experimental design was randomized blocks with three replicates. The cultivars were sown in December 2016, in no-tillage system, in Ponta Grossa, Paraná, Brazil (-25.093056, -50.063327 UTM). The analyzed variables were: oil and protein contents, acidity index and specific mass. It was concluded that there were no significant differences among the cultivars for oil and protein contents. For the variables acidity index and specific mass, there were significant differences among the cultivars, being below the limits established by the Brazilian legislation for vegetable oil, but with potential for biodiesel production

    Influence of Altitude on the indirect Analysis of α-amylase Content on Wheat Flours

    Full text link
    The objective of this study was to verify the influence of altitude on the indirect analysis of α-amylase content on wheat flours. The experimental designused was completely randomized, with eight treatments and three repetitions. The treatments consisted of the analysis of the falling number from flours of four wheat classes (basic, domestic, bread and improver) on the elevations zero, 412, 540, 761, 934, 975, 1,040 and 1,095 meters. After the trial results, under the correction of the averages above 600 meters of elevation, it was verified that there was a significant difference between the results of distinct altitudes, for the four wheat classes. When a polynomial regression is applied, for the values without correction, it was obtained that aquadratic regression equation correlates the falling number values with altitude; however, the coefficient of determination was very low, highlighting the major influence of the different equipments that were used to measure the falling number instead of the different altitudes

    Structural and Luminescence Properties of Silica-Based Hybrids Containing New Silylated-Diketonato Europium(III) Complex

    Get PDF
    A new betadiketonate ligand displaying a trimethoxysilyl group as grafting function and a diketone moiety as complexing site (TTA-Si = 4,4,4-trifluoro-2-(3-trimethoxysilyl)propyl)-1-3-butanedione (C4H3S)COCH[(CH2)3Si(OCH3)3]COCF3) and its highly luminescent europium(III) complex [Eu(TTA-Si)3] have been synthesized and fully characterized. Luminescent silica-based hybrids have been prepared as well with this new complex grafted on the surface of dense silica nanoparticles (28 (+/-3 nm) or on mesoporous silica particles. The covalent bonding of Eu(TTA-Si)3 inside the core of uniform silica nanoparticles (40 (+/- 5 nm) was also achieved. Luminescence properties are discussed in relation to the europium chemical environment involved in each of the three hybrids. The general methodology proposed allowed high grafting ratios and overcame chelate release and tendency to agglomeration, and it could be applied to any silica matrix (in the core or at the surface, nanosized or not, dense or mesoporous) and therefore numerous applications such as luminescent markers and luminophors could be foreseen

    Could the variation in quasar luminosity, due to extra dimension 3-brane in RS model, be measurable?

    Full text link
    We propose an alternative theoretical approach showing how the existence of an extra dimension in RS model can estimate the correction in the Schwarzschild radius of black holes, and consequently its measurability in terms of the variation of quasar luminosity, which can be caused by a imprint of an extra dimension endowing the geometry of a brane-world scenario in an AdS_5 bulk. This paper is intended to investigate the variation of luminosity due to accretion of gas in black holes (BHs) in the center of quasars, besides also investigating the variation of luminosity in supermassive BHs by brane-world effects, using RS model.Comment: Revtex4, 7 Pages, 6 Figures, v2 has minor change

    Adequação de propriedades rurais ao Código Florestal Brasileiro: estudo de caso no Estado do Paraná.

    Get PDF
    O Código Florestal Brasileiro de 1965 conceitua e regulamenta as Áreas de Preservação Permanente (APP) e Reserva Legal (RL). Para regulamentar a adequação das propriedades agrícolas ao código florestal, o estado do Paraná instituiu o SISLEG - Sistema de Manutenção, Recuperação e Proteção da Reserva Legal e Áreas de Preservação Permanente. Neste estudo foram quantificadas, com auxílio do sistema de posicionamento global (GPS) e programas de Sistemas de Informações Geográficas (SIG), as APPs e RLs de 147 propriedades em oito municípios das regiões centro-oriental e sudeste do Paraná, visando analisá-las frente ao Código Florestal vigente. Observou-se expressiva cobertura florestal formada por fragmentos de Floresta Ombrófila Mista; as superfícies disponíveis para definição de RL apresentam valores superiores àqueles requeridos pela legislação. Há necessidade de recomposição das APPs em 67% das propriedades; 26% das propriedades estão de acordo com as exigências do Código Florestal. A quantificação da cobertura florestal necessária e remanescente, tal como a pequena demanda de área para readequação de APP (5% da área total) permitem inferir que esses quesitos não são entraves para a regularização ambiental da agricultura familiar, nas propriedades analisadas
    corecore