12,092 research outputs found

    Analysis of the velocity field of granular hopper flow

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    We report the analysis of radial characteristics of the flow of granular material through a conical hopper. The discharge is simulated for various orifice sizes and hopper opening angles. Velocity profiles are measured along two radial lines from the hopper cone vertex: along the main axis of the cone and along its wall. An approximate power law dependence on the distance from the orifice is observed for both profiles, although differences between them can be noted. In order to quantify these differences, we propose a Local Mass Flow index that is a promising tool in the direction of a more reliable classification of the flow regimes in hoppers

    Irreversibility line and low-field grain-boundary pinning in electron-doped superconducting thin films

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    AC magnetic susceptibilities of electron-doped Pr_{1.85}Ce_{0.15}CuO_4 (PCCO) and Sm_{1.85}Ce_{0.15}CuO_4 (SCCO) granular thin films have been measured as a function of temperature and magnetic-field strength. Depending on the level of homogeneity of our films, two different types of the irreversibility line (IL) defined as the intergrain-loss peak temperature in the imaginary part of susceptibility have been found. The obtained results are described via the critical-state model taking into account the low-field grain-boundary pinning. The extracted pinning-force densities in more granular SCCO films turn out to be four times larger than their counterparts in less granular PCCO films

    Dynamical reentrance and geometry imposed quantization effects in Nb-AlOx-Nb Josephson junction arrays

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    In this paper, we report on different phenomena related to the magnetic properties of artificially prepared highly ordered (periodic) two-dimensional Josephson junction arrays (2D-JJA) of both shunted and unshunted Nb-AlOx-Nb tunnel junctions. By employing mutual-inductance measurements and using a high-sensitive bridge, we have thoroughly investigated (both experimentally and theoretically) the temperature and magnetic field dependence of complex AC susceptibility of 2D-JJA. We also demonstrate the use of the scanning SQUID microscope for imaging the local flux distribution within our unshunted arrays

    A cultura da goiaba.

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    bitstream/item/128279/1/PLANTAR-Goiaba-ed02-2010.pdf2. ed. rev. e ampl.Autores: Adriane Luciana da Silva, Alessandra Monteiro S. Mendes, Anderson Ramos de Oliveira, Beatriz Aguiar Jordão Paranhos, Carlos Antonio Fernades Santos, Davi José Silva, Débora Costa Bastos, Diógenes da Cruz Batista, Flávia Rabelo Barbosa, José Eudes de Morais Oliveira, José Lincoln Pinheiro de Araújo, José Maria Pinto, José Mauro da Cunha e Castro, José Monteiro Soares, Luís Henrique Bassoi, Luiz Gonzaga Neto, Magna Soelma Bezerra de Moura, Marcelo Calgaro, Maria Auxiliadora Coêlho de Lima, Mirtes Freitas Lima, Rebert Coelho Correia, Vanderlise Giongo Petrere. Projeto Minibibliotecas

    Use of Machine Learning Models of the ”Transformers” Type in the Construction of Services in a Gamified Web app.

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    The purpose of this document is to describe the use of a natural language processing model in the multiplatform system ”Gamivity” by means of a sentence similarity algorithm to offer a personalized experience module based on the conceptual relationship between questions. For the selection process, certain criteria were chosen that will allow several pre-trained models under the “Transformers” architecture for evaluation, later. These criteria were the language with which the model was altered; Python was the programming language used for the implementation. Regarding the evaluation phase of the selected models, the ”Sentence Transformers” library of the Python programming language was used. In addition, a work environment analogous to the module present in the ”Gamivity” system was built, in which the development platform ”Google Colab” was used to test these models. The criteria for choosing the candidate model were based on its effectiveness in relation to questions as well as the computational cost involved while performing the operations in the said model Based on the applied methodology, the model that yielded the best results was ”paraphrase-multilingual- MiniLM-L12-v2,” modified with a large corpus of text in Spanish and 50 other languages, which showed a degree of precision. When it comes to conceptually relating the questions provided it was found to be optimal, having relatively low computational cost when performing these operations. Keywords: sentence transformers, sentence similarity, relate questions, personalized learning. Resumen El presente documento, tiene como propósito el de describir la utilización de un modelo de procesamiento de lenguaje natural en el sistema multiplataforma “Gamivity”, por medio de un algoritmo de similitud de oraciones para ofrecer un módulo de experiencia personalizada a partir de la relación conceptual entre preguntas. Para el proceso de selección, se establecieron ciertos criterios que permitieron elegir varios modelos pre entrenados bajo la arquitectura “Transformers” para su posterior evaluación. Dichos criterios, fueron el idioma con el que fue entrenado el modelo, así como que el lenguaje de programación utilizado para la implementación fuese Python. En lo que concierne a la fase de evaluación de los modelos seleccionados, se hizo uso de la biblioteca “Sentence Transformers” del lenguaje de programación Python, además se construyó un entorno de trabajo análogo al módulo presente en el sistema “Gamivity”, en la plataforma de desarrollo “Google Colab” para poner a prueba dichos modelos, los criterios para la elección del modelo candidato, se resumen en la eficacia a la hora de relacionar preguntas, así como el coste computacional a la hora de realizar las operaciones involucradas en dicho proceso. A partir de la metodología aplicada, el modelo que mejor resultados generó fue “paraphrase-multilingual-MiniLM L12-v2”, entrenado con un gran corpus de texto en español, así como de otros 50 idiomas, el cual mostró un grado de precisión óptimo a la hora de relacionar conceptualmente las preguntas proporcionadas, así como su relativo bajo coste computacional a la hora de efectuar dichas operaciones. Palabras Clave: sentence transformers, sentence similarity, relacionar preguntas, aprendizaje personalizado

    Avaliação do controle químico na malformação da mangueira irrigada, no Submédio do Vale do rio São Francisco, Brasil.

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    O cultivo de espécies frutíferas na região semi-árida do Nordeste brasileiro vem crescendo continuamente, destacando-se a mangueira pelo valor comercial de seus frutos nos mercados nacional e internacional. As características edafoclimáticas da região e o manejo fitotécnico empregado nesta cultura têm possibilitado a obtenção de produtividades elevadas. No entanto, com a intensificação do cultivo o potencial de inóculo de patógenos tem aumentado, tornando as doenças uma ameaça constante. Dentre eles, merece especial atenção, a malformação floral e/ou vegetativa, dada a sua rápida disseminação e elevada redução da produtividade. Esses fatores motivaram a realização do presente trabalho visando avaliar o efeito de produtos químicos sobre a doença, em mangueiras irrigadas na região do Submédio do Vale do rio São Francisco. O experimento foi instalado em 01/06/1999, em pomar comercial, cultivar Tommy Atkins, de 4,5 anos de idade, em estádio inicial de florescimento. O índice de infestação inicial da doença foi determinado em 5,21%. O delineamento experimental composta de três plantas. Os produtos com suas respectivas dosagens, em p. c. por 100 litros de água, foram: thiabendazole 600 PM (75g), tebuconazole 200 CE + benomyl 500 PM (100 ml + 60g), tolylfluanid PM + tebuconazole 200 CE (150g + 100 ml), benomyl 500 PM (60 g), carboxin + thiram 200 SC (100 ml, kresoxim-methyl SC (20 ml), Azoxystrobin WG (20 g), epoxiconnazole 125 SC (150 ml). A testemunha foi representada por um tratamento sem produto. Utilizaram-se como parâmetros, o número de panículas malformadas e índice de infestação da doença. Os resultados obtidos aos 60 dias após a aplicação dos produtos, não evidenciaram diferenças estatísticas entre os tratamentos em relação aos parâmetros avaliados.Coordenado por Abel Rebouças São José, Tiyoko Nair Hojo Rebouça~s, Daniel Nieto Angel, Ivan Vilas Bôas Souza, Nilma Oliveira Dias, Marinês Pereira Bomfim. Trabalhos apresentados no I Simpósio Latino Americano sobre Produção de Manga, 1999, Vitória da Conquista, BA
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