2,269 research outputs found

    Spreading of thin films assisted by thermal fluctuations

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    We study the spreading of viscous drops on a solid substrate, taking into account the effects of thermal fluctuations in the fluid momentum. A nonlinear stochastic lubrication equation is derived, and studied using numerical simulations and scaling analysis. We show that asymptotically spreading drops admit self-similar shapes, whose average radii can increase at rates much faster than these predicted by Tanner's law. We discuss the physical realizability of our results for thin molecular and complex fluid films, and predict that such phenomenon can in principal be observed in various flow geometries.Comment: 5 pages, 3 figure

    An FPGA-based controller for collaborative robotics

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    The use of robots is becoming more common in society. Industrial robots are being developed to work with people, and lower-force collaborative robots are being developed to help people in their everyday lives. These may need fast and sophisticated motion control and behavioral algorithms, but are expected to be more compact and lower cost. This paper proposes a processor plus FPGA solution for the control systems for such robots, where the FPGA performs all real-time tasks, freeing the processor to run lower-frequency high level control and interface to other devices such as camera systems. A demonstrator robot is designed, combining multi-axis motion control with 3D robot vision

    Riscos genéticos da produção de híbridos de peixes nativos.

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    A produção de peixes nativos e seus híbridos chama a atenção daqueles que observam o Brasil como alvo de investimentos agropecuários e futura potência da aquicultura mundial. Dada a competitividade e dinamismo, o mercado aquícola nacional tem motivado a produção de híbridos em maior escala nos últimos anos, buscando neles características favoráveis de ganho de peso, resistência ao frio, rusticidade e adaptação à alimentação artificial. Por outro lado, a mistura de animais híbridos sobre as linhagens puras e o seu escape inadvertido para os ambientes naturais certamente expõe a sustentabilidade da aquicultura. Sendo assim, este documento buscou reunir informações sobre a produção, impacto genético, riscos e desafios do cultivo de híbridos frente ao desafio de equilibrar a conservação da biodiversidade com a produção sustentável de alimentos.bitstream/item/131431/1/cnpasadoc3.pd

    Broodstock management: cryopreservation parameters to select native tropical fish.

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    Genetic management of broodstock aims to produce fingerlings of superior quality from the adoption of practices and technological processes that assist in the control of the breeders. For this effective control, the fish farmer must avoid matings that would yield inbreeding and select the best breeders by the sperm quality

    Perilaku Reptilia Ketika Gerhana Matahari Parsial di PASTY YOGYAKARTA

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    Perilaku Reptilia di Pasar Aneka Satwa & Tanaman Hias Yogyakarta diamati ketika peristiwa gerhana matahari parsial pada 9 Maret 2016. Faktor lingkungan seperti intensitas cahaya, suhu, dan kelembaban udara diamati dan dicatat. Perilaku Kura-Kura, Biawak, dan Ular diamati dengan metode focal point sampling. Ular cenderung memiliki pergerakan yang terbatas, sedangkan biawak dan kura-kura diam sejenak. Perbedaan perilaku reptilia ketika gerhana matahari sebagian ditentukan oleh jenisnya dan faktor lain yang berbeda-beda

    Synthesis of folic acid functionalized gold nanoclusters for targeting folate receptor-positive cells

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    We report on the synthesis of water-soluble gold nanoclusters capped with polyethylene glycol (PEG)-based ligands and further functionalized with folic acid for specific cellular uptake. The dihydrolipoic acid-PEG-based ligands terminated with -OMe, -NH2 and -COOH functional groups are produced and used for surface passivation of Au nanoclusters (NCs) with diameters <2 nm. The produced sub 2 nm Au NCs possess long-shelf life and are stable in physiologically relevant environments (temperature and pH), are paramagnetic and biocompatible. The paramagnetism of Au NCs in solution is also reported. The functional groups on the capping ligands are used for direct conjugation of targeting molecules onto Au NCs without the need for post synthesis modification. Folic acid (FA) is attached via an amide group and effectively target cells expressing the folate receptor. The combination of targeting ability, biocompatibility and paramagnetism in FA-functionalized Au NCs is of relevance for their exploitation in nanomedicine for targeted imaging
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