15 research outputs found

    Revision and cladistics of the Neotropical genus Pseudoptilolepis Snyder (Diptera, Muscidae) RevisĂŁo e cladĂ­stica do gĂȘnero neotropical Pseudoptilolepis Snyder (Diptera, Muscidae)

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    Pseudoptilolepis Snyder, 1949, a monophyletic Neotropical muscid genus of six species, is reviewed to include four new species, P. centralis sp. nov., P. chrysella sp. nov., P. crocina sp. nov. and P. elbida sp. nov. A taxonomic key is provided for the genus. The phylogenetic relationship among the studied species is: (P. centralis ((P. chrysella (P. fluminensis, P. fulvapoda)) (P. nudapleura (P. elbida (P. nigripoda, P. crocina))))). The geographic distribution of the species is also presented and briefly discussed.<br>O gĂȘnero Neotropical monofilĂ©tico Pseudoptilolepis Snyder, 1949 Ă© revisado para a inclusĂŁo de quatro espĂ©cies novas, P. centralis sp. nov., P. chrysella sp. nov., P. crocina sp. nov. and P. elbida sp. nov. Uma chave taxonĂŽmica para o gĂȘnero Ă© fornecida. A relação filogenĂ©tica entre as espĂ©cies estudadas Ă©: (P. centralis ((P. chrysella (P. fluminensis, P. fulvapoda)) (P. nudapleura (P. elbida (P. nigripoda, P. crocina))))). A distribuição geogrĂĄfica das espĂ©cies Ă© tambĂ©m apresentada e brevemente discutida

    Modeling of time-resolved laser-induced incandescence transients for particle sizing in high-pressure spray combustion environments: a comparative study

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    Contains fulltext : 35660.pdf (publisher's version ) (Closed access)In this study experimental single-pulse, time-resolved laser-induced incandescence (TIRE-LII) signal intensity profiles acquired during transient Diesel combustion events at high pressure were processed. Experiments were performed between 0.6 and 7 MPa using a high-temperature high-pressure constant volume cell and a heavy-duty Diesel engine, respectively. Three currently available LII sub-model functions were investigated in their performance for extracting ensemble mean soot particle diameters using a least-squares fitting routine, and a "quick-fit" interpolation approach, respectively. In the calculations a particle size distribution as well as the temporal and spatial intensity profile of the heating laser was taken into account. For the poorly characterized sample environments of this work, some deficiencies in these state-of-the-art data evaluation procedures were revealed. Depending on the implemented model function, significant differences in the extracted particle size parameters are apparent. We also observe that the obtained "best-fit" size parameters in the fitting procedure are biased by the choice of their respective "first-guess" initial values. This behavior may be caused by the smooth temporal profile of the LII cooling curve, giving rise to shallow local minima on the multi-parameter least squares residuals, surface sampled during the regression analysis procedure. Knowledge of the gas phase temperature of the probed medium is considered important for obtaining unbiased size parameter information from TIRE-LII measurements

    Dynamics of fast ions during sawtooth oscillations in the TEXTOR tokamak measured by collective Thomson scattering

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    Experimental investigations of sawteeth interaction with fast ions measured by collective Thomson scattering on TEXTOR are presented. Time-resolved measurements of localized 1D fast-ion distribution functions allow us to study fast-ion dynamics during several sawtooth cycles. Sawtooth oscillations interact strongly with the fast-ion population in a wide range of plasma parameters. Part of the ion phase space density oscillates out of phase with the sawtooth oscillation during hydrogen neutral beam injection (NBI). These oscillations most likely originate from fast hydrogen ions with energies close to the full injection energy. At lower energies passing fast ions in the plasma centre are strongly redistributed at the time of sawtooth collapse but no redistribution of trapped fast ions is observed. The redistribution of fast ions from deuterium NBI in the plasma centre is found to vary throughout velocity space. The reduction is most pronounced for passing ions. We find no evidence of inverted sawteeth outside the sawtooth inversion surface in the fast-ion distribution function
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