1,031 research outputs found

    Peanut leaf spot disease identification using pre-trained deep convolutional neural network

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    Reduction of quality and quantity of agricultural products, particularly peanut or groundnut, is usually associated with disease. This could be solved through automatic identification and diagnoses using deep learning. However, this technology is not yet explored and examined in the case of peanut leaf spot disease due to some aspects, such as the availability of sufficient data to be used for training and testing the model. This study is intended to explore the use of pre-trained visual geometry group–16 (VGG16), visual geometry group–19 (VGG19), InceptionV3, MobileNet, DenseNet, Xception, InceptionResNetV2, and ResNet50 architectures and deep learning optimizers such as stochastic gradient descent (SGD) with Momentum, adaptive moment estimation (Adam), root mean square propagation (RMSProp), and adaptive gradient algorithm (Adagrad) in creating a model that can identify leaf spot disease by using a total of 1,000 images of leaves captured using a mobile camera. Confusion matrix was used to assess the accuracy and precision of the results. The result of the study shows that DenseNet-169 trained using SGD with momentum, Adam, and RMSProp attained the highest accuracy of 98%, while DenseNet-169 trained using RMSProp achieved the highest precision of 98% among pre-trained deep convolutional neural network architectures. Furthermore, this result could be beneficial in agricultural automation and disease identification systems for peanut or groundnut plants

    Cosmological lepton asymmetry with a nonzero mixing angle \theta_{13}

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    While the baryon asymmetry of the Universe is nowadays well measured by cosmological observations, the bounds on the lepton asymmetry in the form of neutrinos are still significantly weaker. We place limits on the relic neutrino asymmetries using some of the latest cosmological data, taking into account the effect of flavor oscillations. We present our results for two different values of the neutrino mixing angle \theta_{13}, and show that for large \theta_{13} the limits on the total neutrino asymmetry become more stringent, diluting even large initial flavor asymmetries. In particular, we find that the present bounds are still dominated by the limits coming from Big Bang Nucleosynthesis, while the limits on the total neutrino mass from cosmological data are essentially independent of \theta_{13}. Finally, we perform a forecast for COrE, taken as an example of a future CMB experiment, and find that it could improve the limits on the total lepton asymmetry approximately by up to a factor 6.6.Comment: 11 pages, 7 figures, 5 tables. v2: updated COrE specifications. v3: matches Phys. Rev. D accepted versio

    Intragranitic locle golcl cleposits in the Tomiño area (Ponteveclra)

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    [Resumen] En este trabajo se describen las principales características de las mineralizaciones auríferas filonianas que aparecen en varios cuerpos graníticos sintectónicos en el área de Tomillo (SW de la provincia de Pontevedra), haciendo también referencia al contexto geológico en el que dichas mineralizaciones se presentan. Se trata de venas y filones de cuarzo con sulfuros (pirita, arsenopirita y calcopirita principalmente), con greisenización asociada, originados como consecuencia de un proceso neumatolítico-hidrotermal controlado por el sistema de fracturas de los granitos encajantes. Pueden diferenciarse cinco paragénesis consecutivas: postmagmática, de endogreisen, hidrotermal temprana, hidrotermal tardía y supergénica. El oro se presenta en forma de inclusiones microscópicas dentro de los sulfuros (principalmente en la calcopirita), que van aumentando en tamaño y proporciór a lo largo de las etapas sucesivas del proceso de mineralización.[Abstract] The main characteristics of lode gold deposits ocurring in sorne syntectonic granitic bodies in the Tomiño Area (SW of Pontevedra province) are described in this work. The geological context of this mineralization type is also referred to. The mineralizations consist of quartz-veins bearing sulphides (mainly pyrite, arsenopyrite and chalcopyrite), with associated greisenization in the wallrock, produced by a pneumatolytic-hydrothermal process that is controlled by the fracture system in the host granites. Five consecutive paragenesis can be distinguished: postmagmatic, endogreisen, early hydrothermal, late hydrothermal and supergene. Gold oeeurs as mieroseopie inelusions inside sulphides (mainly in ehalco-pyrite), inereasing in size and proportion along the sueeesive stages in the mineralization proeess

    B- and C-type low molecular weight glutenin subunits in tetraploid wheat germplasm

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    General knowledge acquisition entails the extraction of statistical regularities from the environment. At high levels of complexity, this may involve the extraction, and consolidation, of associative regularities across event memories. The underlying neural mechanisms would likely involve a hippocampo-neocortical dialog, as proposed previously for system-level consolidation. To test these hypotheses, we assessed possible differences in consolidation between associative memories containing cross-episodic regularities and unique associative memories. Subjects learned face-location associations, half of which responded to complex regularities regarding the combination of facial features and locations, whereas the other half did not. Importantly, regularities could only be extracted over hippocampus-encoded, associative aspects of the items. Memory was assessed both immediately after encoding and 48 h later, under fMRI acquisition. Our results suggest that processes related to system-level reorganization occur preferentially for regular associations across episodes. Moreover, the build-up of general knowledge regarding regular associations appears to involve the coordinated activity of the hippocampus and mediofrontal regions. The putative cross-talk between these two regions might support a mechanism for regularity extraction. These findings suggest that the consolidation of cross-episodic regularities may be a key mechanism underlying general knowledge acquisition

    Gradual transition from insulator to semimetal of Ca1x_{1-x}Eux_{x}B6_{6} with increasing Eu concentration

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    The local environment of Eu2+^{2+} (4f74f^{7}, S=7/2S=7/2) in Ca1x_{1-x}Eux_{x}B6_{6} (0.003x1.000.003\leqslant x\leqslant 1.00) is investigated by means of electron spin resonance (ESR). For x0.003x\lesssim 0.003 the spectra show resolved \textit{fine} and \textit{hyperfine} structures due to the cubic crystal \textit{electric} field and nuclear \textit{hyperfine} field, respectively. The resonances have Lorentzian line shape, indicating an \textit{insulating} environment for the Eu2+^{2+} ions. For 0.003x0.070.003\lesssim x\lesssim 0.07, as xx increases, the ESR lines broaden due to local distortions caused by the Eu/Ca ions substitution. For 0.07x0.300.07\lesssim x\lesssim 0.30, the lines broaden further and the spectra gradually change from Lorentzian to Dysonian resonances, suggesting a coexistence of both \textit{insulating} and \textit{metallic} environments for the Eu2+^{2+} ions. In contrast to Ca1x_{1-x}Gdx_{x}B6_{6}, the \textit{fine} structure is still observable up to x0.15x\approx 0.15. For x0.30x\gtrsim 0.30 the \textit{fine} and \textit{hyperfine} structures are no longer observed, the line width increases, and the line shape is purely Dysonian anticipating the \textit{semimetallic} character of EuB6_{6}. This broadening is attributed to a spin-flip scattering relaxation process due to the exchange interaction between conduction and Eu2+^{2+} 4f4f electrons. High field ESR measurements for x0.15x\gtrsim 0.15 reveal smaller and anisotropic line widths, which are attributed to magnetic polarons and Fermi surface effects, respectively.Comment: Submitted to PR

    Quantum Oscillations in EuFe2As2 single crystals

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    Quantum oscillation measurements can provide important information about the Fermi surface (FS) properties of strongly correlated metals. Here, we report a Shubnikov-de Haas (SdH) effect study on the pnictide parent compounds EuFe2_{2}As2_{2} (Eu122) and BaFe2_{2}As2_{2} (Ba122) grown by In-flux. Although both members are isovalent compounds with approximately the same density of states at the Fermi level, our results reveal subtle changes in their fermiology. Eu122 displays a complex pattern in the Fourier spectrum, with band splitting, magnetic breakdown orbits, and effective masses sistematically larger when compared to Ba122, indicating that the former is a more correlated metal. Moreover, the observed pockets in Eu122 are more isotropic and 3D-like, suggesting an equal contribution from the Fe 3d3d orbitals to the FS. We speculate that these FS changes may be responsible for the higher spin-density wave ordering temperature in Eu122.Comment: 5 pages, 4 figure

    Microscopic evidence for field-induced magnetism in CeCoIn5_5

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    We present NMR data in the normal and superconducting states of CeCoIn5_5 for fields close to Hc2(0)=11.8H_{\rm c2}(0)=11.8 T in the abab plane. Recent experiments identified a first-order transition from the normal to superconducting state for H>10.5H> 10.5 T, and a new thermodynamic phase below 290 mK within the superconducting state. We find that the Knight shifts of the In(1), In(2) and the Co are discontinuous across the first-order transition and the magnetic linewidths increase dramatically. The broadening differs for the three sites, unlike the expectation for an Abrikosov vortex lattice, and suggests the presence of static spin moments in the vortex cores. In the low-temperature and high-field phase the broad NMR lineshapes suggest ordered local moments, rather than a long wavelength quasiparticle spin density modulation expected for an FFLO phase.Comment: 4 pages, 4 figures. to appear in Phys. Rev. Let
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