Fracture characterization of wood under Mode I loading using the SEN-TPB Test

Mode I fracture characterization was induced in wood (Picea abies L.) using the single-edge-notched beamloaded in three-point-bending. A developed data reduction scheme based on the equivalent linear elasticfracture mechanics was used to evaluate the Resistance-curve instead of classical methods. The method isfound on beam theory and crack equivalent concept taking into account the triangular stress relief regionthat develops in the crack vicinity. The method dispenses crack length monitoring in the course of theloading process, providing a complete Resistance-curve which is essential for a clear identification of thefracture energy. The validation of the procedure has been performed numerically using a bilinear cohesivedamage model, thus allowing the simulation of both damage initiation and growth. The numerical modelalso provided the critical specimen dimensions that permit the attainment of accurate evaluation of thefracture toughness in wood

A new method for the identification of cohesive laws under pure loading modes

In this work, a new and simple methodology is proposed to identify the cohesive law of composite materials submitted to pure mode I and II loading. This methodology combines the experimental measured crack opening displacement and corresponding strain energy release rate with numerical simulation, using finite element method including cohesive zone modelling. The proposed procedure was tested and validated numerically, considering the determination of cohesive laws with different shapes for pure mode I and II loading. This was accomplished using the double cantilever beam (mode I) and end-notched flexure (mode II) tests. It was verified that the proposed methodology points towards the unicity of the identified solution and reproduces well the cohesive laws used as input.The first and third author acknowledges the Portuguese Foundation for Science and Technology, under the project UIDB/04033/2020. The second author acknowledges FCT for the conceded financial support through the reference projects PTDC/EME-SIS/28225/2017 and UID/EEA/04436/2019. The fourth author acknowledges the “Laboratório Associado de Energia, Transportes e Aeronáutica”(LAETA) for the financial support by the project UID/EMS/50022/2013, and to the funding of Project NORTE-01-0145-FEDER-000022 - SciTech - Science and Technology for Competitive and Sustainable Industries, co-financed by Programa Operacional Regional do Norte (NORTE2020), through Fundo Europeu de Desenvolvimento Regional (FEDER)

Lunasin and Bowman-Birk Protease Inhibitor Concentrations of Protein Extracts from Enzyme-Assisted Aqueous Extraction of Soybeans

Lunasin and Bowman-Birk protease inhibitor (BBI) are two soybean peptides to which health-promoting properties have been attributed. Concentrations of these peptides were determined in skim fractions produced by enzyme-assisted aqueous extraction processing (EAEP) of extruded full-fat soybean flakes (an alternative to extracting oil from soybeans with hexane) and compared with similar extracts from hexane-defatted soybean meal. Oil and protein were extracted by using countercurrent twostage EAEP of soybeans at 1:6 solids-to-liquid ratio, 50C, pH 9.0, and 120 rpm for 1 h. Protein-rich skim fractions were produced from extruded full-fat soybean flakes using different enzyme strategies in EAEP: 0.5% protease (wt/g extruded flakes) used in both extraction stages; 0.5% protease used only in the second extraction stage; no enzyme used in either extraction stage. Countercurrent two-stage protein extraction of air-desolventized, hexane-defatted soybean flakes was used as a control. Protein extraction yields increased from 66% to 89-96% when using countercurrent two-stage EAEP with extruded full-fat flakes compared to 85% when using countercurrent two-stage protein extraction of air-desolventized, hexane-defatted soybean flakes. Extruding full-fat soybean flakes reduced BBI activity. Enzymatic hydrolysis reduced BBI contents of EAEP skims. Lunasin, however, was more resistant to both enzymatic hydrolysis and heat denaturation. Although using enzymes in both EAEP extraction stages yielded the highest protein and oil extractions, reducing enzyme use to only the second stage preserved much of the BBI and Lunasin

Desempenho de novilhos Sindi em pastagem de capim buffel suplementados com diferentes fontes de proteína, no Sertão de Pernambuco.

O trabalho foi realizado durante período seco, na Estação Experimental da Caatinga da Embrapa Semi-Árido, em Petrolina-PE e objetivou avaliar o desempenho de garrotes da raça Sindi, tendo como base da alimentação o pasto diferido de capim buffel e recebendo suplementação protéica. Dezesseis animais com idade e peso médio iniciais de 18,4 meses e 164 kg, respectivamente, no início do experimento, foram distribuídos em quatro tratamentos recebendo ração balanceadas para apresentarem 20% de proteína bruta (PB). Os tratamentos foram: 1) caroço de algodão (CA), 2) farelo de soja e milho triturado (FSM), 3) palma forrgeira e a uréia + sulfato de amônia (PU) e 4) raspa de mandioca (RM), sendo ofertado 1 kg/cabeça dia com base na matéria seca. Cada período experimental teve duração de 28 dias, sendoiniciado em novembro e indo até o final de janeiro. Houve diferença estatística entre os tratamentos (P<0,05) tanto para ganho de peso total como para ganho médio diário, em que os animais que receberam caroço de algodão ou a mistura milho e farelo de soja tiveram melhor desempenho que aqueles suplementados com raspa de mandioca ou palma forrageira. Os animais tiveram um ganho total de peso no período que variou de 40,5 kg para PU a 66,2 kg para CA. O ganho médio diário foi de 789, 713, 491 e 482 g/dia, respectivamente para CA, FSM, RM e PU. Os suplementos que tinham uréia na composição, limitaram o consumo e ocasionaram para um menor desempenho dos animais

SEMI-ANALYTICAL SOLUTION OF THE HEAT CONDUCTION IN A PLATE WITH HEAT GENERATION

In the present work, a formulation for the solution of the two-dimensional steady state heat conduction with heat generation is presented. The classical integral transform technique (CITT) is used to solve the problem in a semi- analytical manner. CITT deals with expansions of the sought solution in terms of infinite orthogonal basis of eigenfunctions, keeping the solution process always within a continuous domain. For the particular problem, the resulting system is composed of a set of uncoupled differential equations which can be solved analytically. However, a truncation error is involved since the infinite series must be truncated to obtain numerical results. For comparison and validation purposes, the second order central finite difference method (FDM) is also implemented. The convergence analysis showed that CITT has a greater performance having no difficulties to obtain accurate results with very few terms in the solution summation. The FDM had convergence troubles specially for the positions near the center and for high concentration of heat generation in the center of the plate

Equilibria-based Probabilistic Model Checking for Concurrent Stochastic Games

Probabilistic model checking for stochastic games enables formal verification of systems that comprise competing or collaborating entities operating in a stochastic environment. Despite good progress in the area, existing approaches focus on zero-sum goals and cannot reason about scenarios where entities are endowed with different objectives. In this paper, we propose probabilistic model checking techniques for concurrent stochastic games based on Nash equilibria. We extend the temporal logic rPATL (probabilistic alternating-time temporal logic with rewards) to allow reasoning about players with distinct quantitative goals, which capture either the probability of an event occurring or a reward measure. We present algorithms to synthesise strategies that are subgame perfect social welfare optimal Nash equilibria, i.e., where there is no incentive for any players to unilaterally change their strategy in any state of the game, whilst the combined probabilities or rewards are maximised. We implement our techniques in the PRISM-games tool and apply them to several case studies, including network protocols and robot navigation, showing the benefits compared to existing approaches

Weevil associated to gummosis in oil palm (Elaeis guineensis Jacq.) in Brazil.

In commercial plantations of oil palm in Nazare municipality, state of Bahia, Brazil, the association of Rhinostomus barbirostris Fabricius and Ceratocystis paradoxa (Dade) C. Moreau in high number of oil palm trees showing stem bleeding symptoms was observed. The pathogen was isolated from tissues of diseased oil palm plants. To our knowledge this is the first report on the contribution of R. barbirostris to increase the severity of stem bleeding disease caused by C. paradoxa in oil palm. Control measures are suggested

Magnon delocalization in ferromagnetic chains with long-range correlated disorder

We study one-magnon excitations in a random ferromagnetic Heisenberg chain with long-range correlations in the coupling constant distribution. By employing an exact diagonalization procedure, we compute the localization length of all one-magnon states within the band of allowed energies $E$. The random distribution of coupling constants was assumed to have a power spectrum decaying as $S(k)\propto 1/k^{\alpha}$. We found that for $\alpha < 1$, one-magnon excitations remain exponentially localized with the localization length $\xi$ diverging as 1/E. For $\alpha = 1$ a faster divergence of $\xi$ is obtained. For any $\alpha > 1$, a phase of delocalized magnons emerges at the bottom of the band. We characterize the scaling behavior of the localization length on all regimes and relate it with the scaling properties of the long-range correlated exchange coupling distribution.Comment: 7 Pages, 5 figures, to appear in Phys. Rev.

Ganho esperado na seleção de progênies de Pinus elliottii var. elliottii em idade precoce para produção de madeira.

Pinus elliotti var. elliottii é a segunda espécie mais utilizada em reflorestamentos nas regiões subtropicais do Brasil, devida a sua boa performance na produção de madeira e resina. Assim, o objetivo do presente trabalho foi estimar os parâmetros genéticos e predizer os ganhos genéticos possíveis mediante seleções em idade precoce em progênies de P. elliottii para a produção de madeira. O experimento foi estabelecido no delineamento em blocos completos casualizados, com 76 tratamentos (75 progênies de um pomar de sementes clonal e um controle de plantio comercial), no espaçamento de 3 m x 3 m. A altura total foi avaliada no primeiro, segundo e terceiro anos após o plantio e o diâmetro a 1,30 m do solo (DAP) somente no terceiro ano após o plantio. O volume individual de madeira e o incremento médio anual foram calculados com base nesses caracteres. As análises de deviance e as estimativas dos parâmetros genéticos foram realizadas com o programa Selegen-REML/BLUP. Variação genética significativa foi detectada entre progênies. As herdabilidades individuais no sentido restrito foram de 0,25 e 0,42 em DAP e altura, respectivamente. Conclui-se que a variação genética é suficientemente alta para possibilitar ganhos genéticos mediante seleção dos indivíduos e progênies mais produtivos, visando à composição de pomares de sementes e plantios comerciais, tendo sido observado genótipos mais produtivos do que o plantio comercial