5,305 research outputs found

    Structural properties of crumpled cream layers

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    The cream layer is a complex heterogeneous material of biological origin which forms spontaneously at the air-milk interface. Here, it is studied the crumpling of a single cream layer packing under its own weight at room temperature in three-dimensional space. The structure obtained in these circumstances has low volume fraction and anomalous fractal dimensions. Direct means and noninvasive NMR imaging technique are used to investigate the internal and external structure of these systems.Comment: 9 pages, 4 figures, accepted in J. Phys. D: Appl. Phy

    On Deciding Local Theory Extensions via E-matching

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    Satisfiability Modulo Theories (SMT) solvers incorporate decision procedures for theories of data types that commonly occur in software. This makes them important tools for automating verification problems. A limitation frequently encountered is that verification problems are often not fully expressible in the theories supported natively by the solvers. Many solvers allow the specification of application-specific theories as quantified axioms, but their handling is incomplete outside of narrow special cases. In this work, we show how SMT solvers can be used to obtain complete decision procedures for local theory extensions, an important class of theories that are decidable using finite instantiation of axioms. We present an algorithm that uses E-matching to generate instances incrementally during the search, significantly reducing the number of generated instances compared to eager instantiation strategies. We have used two SMT solvers to implement this algorithm and conducted an extensive experimental evaluation on benchmarks derived from verification conditions for heap-manipulating programs. We believe that our results are of interest to both the users of SMT solvers as well as their developers

    SMT-based Model Checking for Recursive Programs

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    We present an SMT-based symbolic model checking algorithm for safety verification of recursive programs. The algorithm is modular and analyzes procedures individually. Unlike other SMT-based approaches, it maintains both "over-" and "under-approximations" of procedure summaries. Under-approximations are used to analyze procedure calls without inlining. Over-approximations are used to block infeasible counterexamples and detect convergence to a proof. We show that for programs and properties over a decidable theory, the algorithm is guaranteed to find a counterexample, if one exists. However, efficiency depends on an oracle for quantifier elimination (QE). For Boolean Programs, the algorithm is a polynomial decision procedure, matching the worst-case bounds of the best BDD-based algorithms. For Linear Arithmetic (integers and rationals), we give an efficient instantiation of the algorithm by applying QE "lazily". We use existing interpolation techniques to over-approximate QE and introduce "Model Based Projection" to under-approximate QE. Empirical evaluation on SV-COMP benchmarks shows that our algorithm improves significantly on the state-of-the-art.Comment: originally published as part of the proceedings of CAV 2014; fixed typos, better wording at some place

    Critical wave-packet dynamics in the power-law bond disordered Anderson Model

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    We investigate the wave-packet dynamics of the power-law bond disordered one-dimensional Anderson model with hopping amplitudes decreasing as HnmnmαH_{nm}\propto |n-m|^{-\alpha}. We consider the critical case (α=1\alpha=1). Using an exact diagonalization scheme on finite chains, we compute the participation moments of all stationary energy eigenstates as well as the spreading of an initially localized wave-packet. The eigenstates multifractality is characterized by the set of fractal dimensions of the participation moments. The wave-packet shows a diffusive-like spread developing a power-law tail and achieves a stationary non-uniform profile after reflecting at the chain boundaries. As a consequence, the time-dependent participation moments exhibit two distinct scaling regimes. We formulate a finite-size scaling hypothesis for the participation moments relating their scaling exponents to the ones governing the return probability and wave-function power-law decays

    Development of an acai-soymilk beverage: characterization and consumer acceptance.

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    Made available in DSpace on 2011-04-09T22:24:05Z (GMT). No. of bitstreams: 1 2010182.pdf: 327703 bytes, checksum: 6fb192c968aab0ed074317a04ed8d504 (MD5) Previous issue date: 2011-02-09201

    Content and label diagnosis of commercialized herbal drug of Uncaria tomentosa (Willd.) DC. in Rio de Janeiro and Minas Gerais.

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    Uncaria tomentosa, known as cat's claw, is a medicinal plant used as antiinflammatory in folk medicine and in SUS fitotherapy. To ensure safety and effectiveness in its use, it's necessary to certify the authenticity of the drug. This work aims to know if the herb drugs of U. tomentosa offered in Rio de Janeiro and Minas Gerais markets are authentic, and if their labels are according to RDC10/2010

    Goat milk production and quality on Tanzania-grass pastures, with supplementation.

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    It was evaluated the production and quality of milk produced by goats grazing Panicum maximum Jacq cv. Tanzania (Guineagrass) and receiving four levels of concentrate supplementation. Eight Anglo Nubian goats, aged between two and four years, 43.6 kg in average body weight and between the 2nd and 4th lactation were distributed into two 4 x 4 balanced Latin square design. The supplementation levels were: 0.0, 0.5, 1.0 and 1.5% of body weight. The concentrate was composed of corn and soybean meal. The intake of dry matter and nutrients, and the daily production of milk, 4% fat-corrected milk, fat, protein, lactose and total solids had increased (p < 0.05) with supplementation, whereas fat and total solids percentage were reduced (p < 0.05). The concentrate supplementation up to 1.5% of live weight in Tanzania-grass pasture raises the intake of dry matter and nutrients, resulting in a linear increase in milk production and of its components. [Produção e qualidade do leite de cabras em pasto cultivado de capim-Tanzânia suplementadas com concentrado]. Resumo: Avaliou-se a produção e qualidade do leite de cabras em pasto cultivado de Panicum maximum Jacq cv. Tanzânia sob níveis de suplementação com concentrado. Foram utilizadas oito cabras da raça Anglonubiana, com idade entre dois e quatro anos, peso médio de 43,6 kg, entre a 2ª e 4ª ordem de lactação, distribuídas em duplo quadrado latino balanceado 4 x 4. Os níveis de suplementação avaliados foram: 0,0; 0,5; 1,0 e 1,5% do peso vivo. O concentrado, foi composto por grão de milho e farelo de soja. O consumo de matéria seca e de nutrientes e as produções diárias de leite, de leite corrigido a 4% de gordura, gordura, proteína, lactose e sólidos totais aumentaram com a suplementação, enquanto que os teores de gordura e sólidos totais reduziram. A suplementação com concentrado em até 1,5% do peso vivo em pasto cultivado de capim-tanzânia promove aumento no consumo de matéria seca e de nutrientes da dieta, do que resulta o aumento linear na produção de leite e de seus constituintes
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