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61.
62.
B. Batscha J. M. Kolthoff E. A. Pearson L. Cuny J. Golse und H. N. Thomson 《Fresenius' Journal of Analytical Chemistry》1933,94(1-2):44-46
Ohne Zusammenfassung 相似文献
63.
64.
Ohne Zusammenfassung 相似文献
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Simplified models have been used to simulate and study the flow-induced vibrations of the human vocal folds. While it is clear that the models' responses are sensitive to geometry, it is not clear how and to what extent specific geometric features influence model motion. In this study geometric features that played significant roles in governing the motion of a two-layer (body-cover), two-dimensional, finite element vocal fold model were identified. The model was defined using a flow solver based on the viscous, unsteady, Navier-Stokes equations and a solid solver that allowed for large strain and deformation. A screening-type design-of-experiments approach was used to identify the relative importance of 13 geometric parameters. Five output measures were analyzed to assess the magnitude of each geometric parameter's effect on the model's motion. The measures related to frequency, glottal width, flow rate, intraglottal angle, and intraglottal phase delay. The most significant geometric parameters were those associated with the cover--primarily the pre-phonatory intraglottal angle--as well as the body inferior angle. Some models exhibited evidence of improved model motion, including mucosal wave-like motion and alternating convergent-divergent glottal profiles, although further improvements are still needed to more closely mimic human vocal fold motion. 相似文献
67.
F. Migliorini K. A. Thomson G. J. Smallwood 《Applied physics. B, Lasers and optics》2011,104(2):273-283
The optical properties of soot, in particular the propensity of soot to absorb and scatter light as a function of wavelength,
are key parameters for the correct interpretation of soot optical diagnostics. An overview of the data available in the literature
highlights the differences in the reported optical properties of aging soot. In many cases, the properties of mature soot
are used when evaluating in-flame soot but this assumption might not be suitable for all conditions and should be checked.
This need has been demonstrated by performed spectral resolved line-of-sight attenuation (Spec-LOSA) measurements on an ethylene/air
premixed and non-premixed flame. Transmission electron microscopy of thermophoretically sampled soot was also performed to
qualify the soot aging and to establish soot morphology in order to correct light extinction coefficients for the scattering
contribution. The measured refractive index absorption function, E(m)
λ
, showed a very strong spectral dependence which also varied with height above the burner for both flames. However, above
700 nm, the slope of the refractive index function was near zero for both flames and all measurement heights. The upper visible
and near infrared wavelengths are therefore recommended for soot optical measurements. 相似文献
68.
M. Köhler K. P. Geigle W. Meier B. M. Crosland K. A. Thomson G. J. Smallwood 《Applied physics. B, Lasers and optics》2011,104(2):409-425
Computational fluid dynamics (CFD) modelers require high-quality experimental data sets for validation of their numerical
tools. Preferred features for numerical simulations of a sooting, turbulent test case flame are simplicity (no pilot flame),
well-defined boundary conditions, and sufficient soot production. This paper proposes a non-premixed C2H4/air turbulent jet flame to fill this role and presents an extensive database for soot model validation. 相似文献
69.
K. A. Thomson K. P. Geigle M. Köhler G. J. Smallwood D. R. Snelling 《Applied physics. B, Lasers and optics》2011,104(2):307-319
To investigate the transient change of soot optical properties resulting from pulsed laser heating of soot in a cooled exhaust
plume we have simultaneously performed cw light extinction at 405 and 830 nm and elastic light scattering at 1064 nm. A reversible
increase to the 830-nm light extinction of up to 7%, observed during the time period where the soot was hot, suggests a temperature-dependent
light absorption refractive index function, E(m
λ
). At low fluence, small permanent increases of E(m
λ
) of <2% were also observed. 405-nm extinction measurements revealed that the soot likely contained material which continued
to absorb 405-nm radiation when desorbed, thus complicating measurement interpretation. 1064-nm light scattering measurements
showed a gradual decrease of scattering propensity with increasing laser fluence up to the point of material loss, which is
consistent with the expected decrease of the structure factor of the soot aggregates as they expand. It is concluded that
variations of the optical properties are occurring at the time of laser-induced incandescence (LII) emission, which should
be accounted for in time-resolved LII measurement interpretation. 相似文献
70.