6,285 research outputs found

    Application of cabin atmosphere monitors to rapid screening of breath samples for the early detection of disease states

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    Analysis of human breath is a nonintrusive method to monitor both endogenous and exogenous chemicals found in the body. Several technologies were investigated and developed which are applicable to monitoring some organic molecules important in both physiological and pathological states. Two methods were developed for enriching the organic molecules exhaled in the breath of humans. One device is based on a respiratory face mask fitted with a polyethylene foam wafer; while the other device is a cryogenic trap utilizing an organic solvent. Using laboratory workers as controls, two organic molecules which occurred in the enriched breath of all subjects were tentatively identified as lactic acid and contisol. Both of these substances occurred in breath in sufficient amounts that the conventional method of gas-liquid chromatography was adequate for detection and quantification. To detect and quantitate trace amounts of chemicals in breath, another type of technology was developed in which analysis was conducted using high pressure liquid chromatography and mass spectrometry

    Microstructure and mechanical properties of bulk yttria-partially-stabilized zirconia

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    A commercially available bulk 4.5 mole percent yttria-(Y2O3) partially stabilized zirconia (PSZ) was studied by light microscopy, X-ray analysis, microhardness measurement, and fracture toughness testing. The growth of the precipitates and the phase transformations were studied as a function of aging in air at 1500 C. Aging curves were constructed for both the as received and the solution annealed and quenched materials; the curves showed hardness peaks at 1397 and 1517 Kg/sq mm respectively. The rectangular plate shaped tetragonal precipitates were found to have a 110 habit plane. A total of twelve different types of tetragonal precipitates were found. Grinding of the Y2O3 PSZ into powder did not cause a significant amount of metastable tetragonal precipitates to transform into the monoclinc phase, thus indicating that transformation toughening is not a significant mechanism for the material

    pyprop8: A lightweight code to simulate seismic observables in a layered half-space

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    The package pyprop8 enables calculation of the response of a 1-D layered halfspace to a seismic source, and also derivatives (‘sensitivity kernels’) of the wavefield with respect to source parameters. Seismograms, seismic spectra, and measures of static displacement (e.g. GPS, InSAR and field observations) may all be simulated. The method is based on a ThompsonHaskell propagator matrix algorithm, described in O’Toole & Woodhouse (2011) and O’Toole et al. (2012). The package is entirely written in Python, dependent only on the mainstream libraries numpy (Harris et al., 2020) and scipy (Virtanen et al., 2020). As such, it is lightweight and easy to deploy across a variety of platforms, making it particularly suited to use for teaching and outreach purposes

    Recombination kinetics in ?-Si:H

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    Journal ArticleMort et al.1 reinterpreted our data on the relaxation of photoinduced absorption (PA) in a-Si:H. 2 We want to show that the proposed interpretation contradicts one basic feature of the data while our original interpretation is in good agreement with experiment

    Optical studies of excess carrier recombination in α-Si:H: evidence of dispersive diffusion

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    Journal ArticleRelaxation of photoinduced optical absorption following pulsed laser excitation was measured between 0.5 pis and 10 ms in doped and undoped a-Si:H as a function of temperature. The recombination was found to be bimolecular diffusion limited. The diffusion coefficient of the excess carriers is time dependent (~t-°3 ) in agreement with the drift mobility of photocarriers and the predictions of the continuous-time random-walk theory of dispersive transport in disordered materials

    Equally attending but still not seeing : an eye-tracking study of change detection in own- and other-race faces

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    The present study aimed to investigate whether the faster change detection in own race faces in a change blindness paradigm, reported by Humphreys, Hodsoll and Campbell (2005, Visual Cognition, 12, 249-262) and explained in terms of people’s poorer ability to discriminate other race faces, may be explained by people’s preferential attention towards own race faces. The study by Humphreys et al. was replicated using the same stimuli, while participants’ eye movements were recorded. These revealed that there was no attentional bias towards own race faces (analysed in terms of fixation order, number and duration), but people still detected changes in own race faces faster than in other race faces. The current results therefore give further support for the original claim that people are less sensitive to changes made in other race faces, when own and other race faces are equally attended
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