37 research outputs found

    The critical parameters in in-situ MgB2 wires and tapes with ex-situ MgB2 barrier after hot isostatic pressure, cold drawing, cold rolling and doping

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    MgB precursor wires were prepared using powder in tube technique by Institute of High Pressure PAS in Warsaw. All samples were annealed under isostatic pressure generated by liquid Argon in the range from 0.3 GPa to 1 GPa. In this paper, we show the effects of different processing routes, namely, cold drawing (CD), cold rolling (CR), hot isostatic pressure (HIP) and doping on critical current density (J), pinning force (F), irreversible magnetic-field (B), critical temperature (T), n value, and dominant pinning mechanism in MgB/Fe wires with ex situ MgB barrier. The results show that medium pressures (∼0.35 GPa) lead to high J in low and medium magnetic fields (0 T - 9 T). On the other hand, higher pressures (∼1 GPa) lead to enhanced J in high magnetic fields (above 9 T). Transport measurements show that CD, CR, and HIP have small effects on B and T, but CD, CR, HIP, and doping enhance J and F in in situ MgB wires with ex situ MgB barrier. Transport measurements on in situ undoped MgB wire with ex situ MgB barrier yield a J of about 100 A/mm at 4.2 K in 6 T, at 10 K in 4 T and at 20 K in 2 T. The results also show that cold drawing causes increase of n value

    Improving biomass production and saccharification in Brachypodium distachyon through overexpression of a sucrose-phosphate synthase from sugarcane

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    The substitution of fossil by renewable energy sources is a major strategy in reducing CO2 emission and mitigating climate change. In the transport sector, which is still mainly dependent on liquid fuels, the production of second generation ethanol from lignocellulosic feedstock is a promising strategy to substitute fossil fuels. The main prerequisites on designated crops for increased biomass production are high biomass yield and optimized saccharification for subsequent use in fermentation processes. We tried to address these traits by the overexpression of a sucrose-phosphate synthase gene (SoSPS) from sugarcane (Saccharum officinarum) in the model grass Brachypodium distachyon. The resulting transgenic B. distachyon lines not only revealed increased plant height at early growth stages but also higher biomass yield from fully senesced plants, which was increased up to 52 % compared to wild-type. Additionally, we determined higher sucrose content in senesced leaf biomass from the transgenic lines, which correlated with improved biomass saccharification after conventional thermo-chemical pretreatment and enzymatic hydrolysis. Combining increased biomass production and saccharification efficiency in the generated B. distachyon SoSPS overexpression lines, we obtained a maximum of 74 % increase in glucose release per plant compared to wild-type. Therefore, we consider SoSPS overexpression as a promising approach in molecular breeding of energy crops for optimizing yields of biomass and its utilization in second generation biofuel production

    Particulate Fillers in Thermoplastics

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    The characteristics of particulate filled thermoplastics are determined by four factors: component properties, composition, structure and interfacial interactions. The most important filler characteristics are particle size, size distribution, specific surface area and particle shape, while the main matrix property is stiffness. Segregation, aggregation and the orientation of anisotropic particles determine structure. Interfacial interactions lead to the formation of a stiff interphase considerably influencing properties. Interactions are changed by surface modification, which must be always system specific and selected according to its goal. Under the effect of external load inhomogeneous stress distribution develops around heterogeneities, which initiate local micromechanical deformation processes determining the macroscopic properties of the composites

    Echinuria uncinata (Rudolphi) (Nematoda, Acuariidae) in Netta peposaca (Vieillot) (Aves, Anatidae) in South America

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    This is the first report of a species of Echinuria Soloviev, 1912, on anatid hosts in South America, causing granulomas. It is also the first detailed description and record of a species of Echinuria, for South America in the Rosy-billed Pochard, Netta peposaca (Vieillot, 1816). Fifty-two rosy-billed pochards were examined for helminths in the Municipalities of Santa Vitória do Palmar (locality of Fazenda Sossego) and (locality of Ponta da Antena), State of Rio Grande do Sul, Brazil, and Alvear, Province of Corrientes, northern Argentina. Samples were obtained from 2003 to 2004. After the catch each bird was immediately frozen with dry ice. Prior to necropsy birds were sexed, weighted, measured, and the state of maturity (juvenile or adult) determined, based on the presence or absence of a bursa of Fabricius. The granulomas with the nematodes were found in the proximal esophagus at the junction with the proventriculus. Two birds had one (fistulated) and two granulomas, respectively. One of the birds was from the wintering grounds along the coastal region in the State of Rio Grande do Sul, southern Brazil. The other, from one of the breeding grounds in northern Argentina, was captured before the trip to the wintering grounds along the migratory flyway. Prevalence was 3.8% while the mean intensity of infection was 7.2. Morphometry of males and females and the comparison with previous descriptions and illustrations allowed the identification of the present specimens as E. uncinata.<br>Este é o primeiro registro de uma espécie do gênero Echinuria Soloviev, 1912, em hospedeiros anatídeos na América do Sul, causando granulomas. É, também, a primeira descrição detalhada e o primeiro registro de Echinuria uncinata (Rudolphi, 1819) Soloviev, 1912, para a América do Sul, e o primeiro registro de um nematóide acuarióideo em Netta peposaca (Vieillot, 1816). Cinqüenta e dois marrecões foram examinados para helmintos nas localidades de Fazenda Sossego e Ponta da Antena, Município de Santa Vitória do Palmar, Estado do Rio Grande do Sul, região Sul do Brasil e Alvear, Província de Corrientes, região Norte da Argentina. As amostras foram obtidas no período de 2003 a 2004. Imediatamente após o abate, cada ave foi congelada em gelo seco. As aves foram separadas por sexo, pesadas e medidas. O estado de maturidade de cada ave foi avaliado (juvenil ou adulto) com base na presença ou ausência da bolsa de Fabricius. Os granulomas, contendo os nematóides, estavam situados na base do esôfago quase junto à junção com o proventrículo. Duas aves estavam positivas, com um (fistulado) e dois granulomas, respectivamente. Uma das aves era proveniente do Brasil (pólo de invernia na planície costeira do Estado do Rio Grande do Sul). A outra da região Norte da Argentina, capturada em um dos pólos de nidificação, antes de empreender sua viagem em direção à costa brasileira ao longo de sua rota de migração. A prevalência da infecção foi de 3,8% e a intensidade média de infecção de 7,2. A morfometria de machos e de fêmeas permitiu a identificação dos espécimes como E. uncinata
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