1,425 research outputs found

    Echo Delay and Overlap with Emitted Orientation Sounds and Doppler-shift Compensation in the Bat, Rhinolophus ferrumequinum

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    The compensation of Doppler-shifts by the bat, Rhinolophusferrumequinum, functions only when certain temporal relations between the echo and the emitted orientation sound are given. Three echo configurations were used: a) Original orientation sounds were electronically Doppler-shifted and played back either cut at the beginning (variable delay) or at the end (variable duration) of the echo. b) Artificial constant frequency echoes with variable delay or duration were clamped to the frequency of the emitted orientation sound at different Doppler-shifts. c) The echoes were only partially Doppler-shifted and the Doppler-shifted component began after variable delays or had variable durations. With increasing delay or decreasing duration of the Doppler-shifted echo the compensation amplitude for a sinusoidally modulated + 3 kHz Dopplershift (modulation rate 0.08 Hz) decreases for all stimulus configurations (Figs. 1, 2, 3). The range of the Doppler-shift compensation system is therefore limited by the delay due to acoustic travel time to about 4 m distance between bat and target. In this range the overlap duration of the echo with the emitted orientation sound is always sufficiently long, when compared with data on the orientation pulse length during target approach from Schnitzler (1968) (Fig. 5)

    Киев-Еганское месторождение нефти

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    Рассматривается геологическое строение Киев-Еганского нефтяного месторождения Томской области, описываются его нефтеносные объекты, отмечается значение данного месторождения с точки зрения поисков нефтяных и газовых месторождений в восточном направлении

    TG-DTA and DSC investigations of ''pinhão'' starch modified by calcium hypochlorite and UV light.

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    Starches, when in its native forms, usually do not have the characteristics required for industrial processing. ''Pinhão'', a seed from the Araucaria angustifolia tree, has starch as main presenting as a great alternative source of starch. Samples of native ''pinhão'' starch were treated with standard calcium hypochlorite solutions (0.1, 0.2 and 0.5 mol L-1) and exposed for one hour under UV light. The modification process applied altered the thermal behavior of the ''pinhão'' starch as the TGA-DTA and DSC results presented.Edição dos Anais do 7º Simpósio de Análise Térmica, 2015, Bauru

    Фотоэлектрохимическое окисление ацетилсалициловой кислоты

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    The progression of neurodegenerative diseases as well as healthy aging is accompanied by structural changes of the brain. These changes are often only subtle when considered over time intervals of several months. Therefore morphometrical techniques for their detection in longitudinally acquired MR images must be highly sensitive, and they require a careful validation. In the present study, a novel processing chain for a longitudinal analysis based on deformation field morphometry is described. Procedures for its quantitative validation are also reported: Deformation fields were computed for the simulation of non-linear, local structural changes of human brains. Applying these deformation fields to "original" MR images yielded deformed MR images. The volume changes defined by the deformation fields represented the standard, against which the results of the longitudinal analysis of each pair of original and deformed MR image were compared. The proposed processing chain enabled to localize and to quantify simulated local atrophies near the cortex as well as in deep brain structures. An exemplary analysis of serial MR images of a patient suffering from an atypical Parkinson syndrome (cortico-basal degeneration, CBD) and healthy control subjects is presented, showing a characteristic pattern of volume changes in the brain of the patient which is strikingly different from the controls' patterns of changes

    Caracterização de amido de pinhão modificado com soluções de ácido clorídrico 0,1 e 0,2M em presença de etanol e metanol.

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    O amido de pinhão possui propriedades interessantes, porém pouco foi estudado até o momento. Proveniente do Sul do Brasil, a semente da Araucária angustifolia serve de alimento para diversas culturas da região. Os amidos nativos de diversas fontes botânicas possuem características de interesse industrial, porém algumas só são adquiridas ou melhoradas mediante a aplicação de agentes que modifiquem as estruturas originais dos grânulos, como ácidos e oxidantes. O presente trabalho teve como objetivo estudar propriedades do amido de pinhão nativo e este modificado, utilizando ácido clorídrico 0,1M e 0,2M, em meio etanólico e metanólico. Pelas curvas DSC foi possível determinar as temperaturas ?onset?, de pico e de conclusão do processo de gelatinização das amostras, além de se determinar a entalpia envolvida no processo. Pelas imagens NC-AFM pode-se medir o tamanho dos grânulos dos amidos e a rugosidade dos mesmos antes e após as modificações. Por meio da técnica TG-DTG, foi possível observar um perfil de perda de massa semelhante para todas as amostras, com 3 etapas definidas, sendo a 1ª referente à desidratação da amostra e a 2ª e 3ª referente à decomposição da matéria orgânica à cinzas. Através da análise de propriedade de pasta (RVA) se observou o perfil reológico das amostras, podendo determinar temperatura de pico, viscosidade final e retrogradação.CBRATEC
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