Active Control of Coherent Structures in an Axisymmetric Jet

The primary objective of this work is to develop high-fidelity simulation model for jet noise control predictions and quantify the sound reduction when an external source frequency mode excitation is imposed on the jet flow. Whereas passive approaches using mixing devices, such as chevrons, have been shown to reduce low-frequency noise in jet engines, such approaches incur a performance penalty since they result in a reduced thrust. To avoid a performance penalty in reducing jet noise, the current work investigates a open-loop active noise control (ANC) system that utilizes a unsteady microjet actuator on the nozzle lip in the downstream direction to produce a desired effect on the jet flow-field dynamics thereby directly affecting the source source. In contrast to the passive approach, the proposed open-loop control design will utilize a local flow excitation device that can be turned off when not needed or adjusted according to the desired control signal. To make it feasible, the effectiveness of every forcing frequency mode has to be mapped for a certain jet velocity. This analysis considers an axisymmetric round jet at supersonic and subsonic speeds. Current studies are verified against previous low-order simulations conducted using Linearized Euler Equations (LEE), and compare qualitatively acheived noise reduction results against available experimental data. High-fidelity analysis, such as Detatched-Eddy Simulations (DES), was implemented using OpenFOAM, an open source CFD software. Results show that some excited frequency modes reduced the far-field jet noise by around 2 dB, supporting the use of unsteady microjet actuators as a jet noise reduction technology

MGBG in Combined Anticancer Chemotherapy

This paper is intended to provide a foundation for further discussion and debate at the plenary panel on “Civility and Academic Freedom” at the National Center’s annual conference on April 20, 2015. The discussion, below, sets forth a structure for evaluating university policies seeking promote “civility” in faculty and student discourse. In particular, this paper evaluates the asserted justifications for civility-related policies and their implications for academic freedom. The paper provides, as well, a list of AAUP materials useful for considering the academic freedom implications of civility-related policies in universities

Assessment of metal exposure (uranium and copper) in fatty acids and carbohydrates profiles of Calamoceras marsupus larvae (Trichoptera) and Alnus glutinosa

Physiological changes were explored in fatty acids (FA) and carbohydrate (CHO) composition in the shredder Calamoceras marsupus larvae (Trichoptera) and leaf litter (C. marsupus food) exposed to copper and uranium under natural and experimental conditions. We measured FA and CHO content in leaf litter and larvae specimens from reference and impacted streams, and exposed for 5 weeks to four realistic environmental concentrations of copper (35 μg L−1 and 70 μg L−1) and uranium (25 μg L−1 and 50 μg L−1). Regarding FA, (1) leaf litter had a reduced polyunsaturated FA (PUFA) content in metal treatments, s (14 to 33% of total FA), compared to natural conditions (≥39% of total FA). Leaf litter exposed to uranium also differed in saturated FA (SFA) composition, with lower values in natural conditions and higher values under low uranium concentrations. (2) C. marsupus had/showed low PUFA content under Cu and U exposure, particularly in high uranium concentrations. Detritivores also decreased in PUFA under exposure to both metals, particularly in high uranium concentrations. On the other hand, (1) microorganisms of the biofilm colonizing leaf litter differed in CHO composition between natural (impacted and reference) and experimental conditions, with glucose and galactose being consistently the most abundant sugars, found in different amounts under copper or uranium exposure; (2) CHO of detritivores showed similar high galactose and fucose concentrations in contaminated streams and high copper treatments, whereas low copper treatment showed distinct CHO profiles, with higher mannose, glucose, arabinose, and fucose concentrations. Our study provides evidence of metal exposure effects on FA and CHO contents at different trophic levels, which might alter the quality of food flow in trophic websFil: Tagliaferro, Marina Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Rocha, Carolina. Universidad de Coimbra. Facultad de Ciencias E Tecnología. Departamento de Ciencias Da Vida; PortugalFil: Marques, Joao Carlos. Universidad de Coimbra. Facultad de Ciencias E Tecnología. Departamento de Ciencias Da Vida; Portugal. Marine And Environmental Sciences Centre; PortugalFil: Goncalves, Ana Marta. Universidad de Coimbra. Facultad de Ciencias E Tecnología. Departamento de Ciencias Da Vida; Portugal. Marine And Environmental Sciences Centre; PortugalVIII Congreso Argentino de la Sociedad de Toxicología y Química AmbientalMar del PlataArgentinaSociedad de Toxicología y Química Ambienta

Wetting of Araucaria angustifolia e Pinus elliottii samples after thermal treatment and aging

Medidas de ângulo de contato, juntamente com as de massa específica, foram realizadas com o intuito de melhor compreender as características de molhabilidade de duas espécies de madeiras, Araucaria angustifolia e Pinus elliottii, sob condições experimentais controladas. O uso de uma técnica de análise térmica comum, a calorimetria exploratória diferencial (DSC), não permitiu com que fossem obtidas conclusões mais precisas sobre as mudanças que ocorrem nas amostras de madeiras estudadas frente a aumentos de temperaturas até cerca de 200 ºC. Porém, as medidas de ângulo de contato mostraram que a molhabilidade das amostras de madeiras diminuia com o aumento da temperatura até 200 ºC e variava com o tempo, tipo de amostra e região de corte da madeira. Uma grande alteração na molhabilidade de ambas as espécies de madeiras foi observada entre 120 ºC e 140 ºC, antes que houvesse uma considerável perda de massa e de diminuição da massa específica aparente. Estas medidas permitam uma diferenciação bastante sensível das espécies de madeiras termorretificadas estudadas abaixo de 200 ºC.Contact angle measurements, along with those of density, were performed in order to better understand the wetting characteristics of two types of wood; from Araucaria angustifolia and Pinus elliottii, under controlled experimental conditions. The use of a common thermal analysis technique, differential scanning calorimetry (DSC), did not lead to accurate conclusions about surface changes that occur with wood samples while increasing the temperatures to 200 ºC. However, the results obtained here showed that the wettability of the wood samples decreased when the temperature reached 200 °C, and also, varied with time, sample type and fracture region. It did vary with time, sample type, and fracture region. A dramatic change in the wettability for both wood samples was verified from 120 ºC to 140 ºC, even before any considerable difference in mass loss and apparent density had been noticed. These measurements enable one to clearly distinguish between wood species which were thermally treated to 200 º C.FAPESPCAPESCNP

Electromyographic activity of trunk muscles during exercises with flexible and non-flexible poles

Objective: Hand-held flexible poles which are brought into oscillation to cause alternating forces on trunk, are advocated as training devices that are supposed to solicit increased levels of stabilizing trunk muscle activity. The aim of this study was to verify this claim by comparing electromyographic (EMG) activity of trunk muscles during exercises performed with a flexible pole and a rigid pole. Methods: Twelve healthy females performed three different exercises with flexible and rigid poles. EMG activity of iliocostalis lumborum (IL), multifidus (MU), rectus abdominis (RA), external oblique (EO) and internal oblique (IO), and was continuously measured. The EMG signals were analyzed in time domain by calculation of the Root Mean Square (RMS) amplitudes over 250 ms windows. The mean RMS-values over time were normalized by the maximum RMS obtained for each muscle. Results: The IO showed a 72% greater EMG activity during the exercises performed with the flexible pole than with the rigid pole (p=0.035). In exercises performed in standing, the IO was significantly more active than when sitting (p=0.006). Conclusion: As intended, the cyclic forces induced by the oscillating pole did increase trunk muscle activation. However, the effect was limited and significant for the IO muscle only. © 2011 - IOS Press and the authors

O uso de subsolo como substrato para a construção de banhados com macrofitas aqüáticas emergentes sob diferentes regimes hídricos

O uso de subsolo como substrato para construção de banhados com macrófitas aquáticas emergentes sob diferentes regimes hídricos. Um solo úmido pode ser formado a partir de solos de terras altas e bem drenadas ao ser propiciada a condição de anaerobiose por inundação contínua. Solos erodidos, ou subsolos normalmente não são favoráveis a biota quando aerados, mas podem sê-lo quando alagados, tornando-se apropriados ao estabelecimento de vegetação de terras úmidas. Neste sentido o experimento testou a utilidade do horizonte B oriundo de um solo Podzólico Vermelho Amarelo (Hapludult) para a construção de banhados considerando-se que as condições de alagamento elevariam pH baixo, reduziriam o elevado e aumentariam a disponibilidade de fósforo (1 a 3ppm) deste substrato, assim como questionando-se se seriam limítantes os baixos teores de matéria orgânica e os altos teores de argilas (0;62±0, I 3, 36,6±5,21, respectivamente) presentes neste. A resposta obtida foi o desenvolvimento da macrófita aquática Typha subulata sob três regimes hídricos: (i) lâmina d'água permanente de 10cm; (ii) lâmína d'água oscilante com recarga de 2,5cm a cada 48 horas e decaimento em 48 horas e (iii) lâmina d'água oscilante com recarga de 2,5cm a cada 48 horas e decaimento em 24 horas, com exposição da camada superficial do solo a condições aeróbias 50% do tempo. Typha subulata estabeleceu-se satisfatoriamente nestes banhados experimentais, e pode ser recomendada como planta pioneira para condições similares. As diferenças significativas entre os tratamentos mostraram que o fator Regime Hídrico provavelmente interagiu com o substrato em relação à disponibilidade de nutrientes. Os processos de fixação de nitrogênio e de solubilização de fósforo, justificariam o crescimento das plantas ter sido favorecido pela inundação permanente. As informações obtidas poderão indicar redução nos custos de implantação de banhados, como estratégia mitigadora, ao recomendar-se a introdução desta espécie sobre subsolos inundados, sem adição de solo fértil.The utilization of subsoil as substract for constructing emergent wetlands under diferent hidric regimes. A wet soil may be formed from a well drained upland soil once has been propiciated an anaerobic condition by continuous flood. Aerated eroded soils or subsoils are not normally favorable to biota but they may be when waterlogged, becoming apropriated to establishment of wetland vegetation. In this direction, the experiment tested the utility of a B horizon from a Red Yelow Podzolic (hapludult) soil to wetland construction considering the water-logged condition would elevate low pH, would reduce the high one and woud increase P availability of this substractum, as questioning if would be limiting the substractum low organic matter and high clay content (0,62±0, 13; 36,6±5,21, respectivily). The response obtained was the development of the emergent aquatic macrophyte Typha subulata under three hidric regimes: (i) I O em permanent water levei; (ii) oscilating water levei with 2,5 em recharge ever 48 and lowering by 48 hours and, e (iii) oseilating water levei with 2,5 em reeharge every 48 hours and lowering by 24 hours, with substractum top layer exposition to aerobie conditions 50% of the time. Typha subulata got satisfactorily established in these experimental wetlands and may be recomended as pioneer plant for similar conditions. The significative differences among treatments indieated the factor hidric regime probabily interact wiht substractum in relation to nutrients availability. The N fixation and P solubilization could explain the plant growth has been greater under permanent water levei. The ínformatíons obtaíned may indicate eost reductions for constructíng wetlands, as mitígatíon strategy, by direetions to introduce 'ljpha subulata over water-logged subsoils, whitout fertile topsoil adition

Rapid turnover of long noncoding RNAs and the evolution of gene expression.

A large proportion of functional sequence within mammalian genomes falls outside protein-coding exons and can be transcribed into long RNAs. However, the roles in mammalian biology of long noncoding RNA (lncRNA) are not well understood. Few lncRNAs have experimentally determined roles, with some of these being lineage-specific. Determining the extent by which transcription of lncRNA loci is retained or lost across multiple evolutionary lineages is essential if we are to understand their contribution to mammalian biology and to lineage-specific traits. Here, we experimentally investigated the conservation of lncRNA expression among closely related rodent species, allowing the evolution of DNA sequence to be uncoupled from evolution of transcript expression. We generated total RNA (RNAseq) and H3K4me3-bound (ChIPseq) DNA data, and combined both to construct catalogues of transcripts expressed in the adult liver of Mus musculus domesticus (C57BL/6J), Mus musculus castaneus, and Rattus norvegicus. We estimated the rate of transcriptional turnover of lncRNAs and investigated the effects of their lineage-specific birth or death. LncRNA transcription showed considerably greater gain and loss during rodent evolution, compared with protein-coding genes. Nucleotide substitution rates were found to mirror the in vivo transcriptional conservation of intergenic lncRNAs between rodents: only the sequences of noncoding loci with conserved transcription were constrained. Finally, we found that lineage-specific intergenic lncRNAs appear to be associated with modestly elevated expression of genomically neighbouring protein-coding genes. Our findings show that nearly half of intergenic lncRNA loci have been gained or lost since the last common ancestor of mouse and rat, and they predict that such rapid transcriptional turnover contributes to the evolution of tissue- and lineage-specific gene expression