Results 211 to 220 of about 289,315 (267)
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Velocity distribution in aortic flow
Cardiovascular Research, 1973Velocity measurements in the dog aorta using a thin film anemometer are described. The instantaneous velocity profiles for the ascending and descending aorta indicate a large inertial core region with relatively thin boundary layers; pronounced non-uniformities are present in the ascending aorta.
C, Clark, D L, Schultz
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``Brillouin Flow'' with Thermal Velocities
Journal of Applied Physics, 1953A type of electron flow in a constant magnetic field is described. The beam of electrons is supposed to be everywhere in thermal equilibrium and the usual Brillouin flow is found when the equilibrium temperature tends to zero. Some considerations are put forward bearing on the choice of a suitable beam temperature in specific problems.
Pierce, J. R., Walker, L. R.
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2000 IEEE Ultrasonics Symposium. Proceedings. An International Symposium (Cat. No.00CH37121), 2002
In recent years, a new method to measure transverse blood flow, based on the decorrelation of the radio frequency (RF) signals has been introduced. We investigated the decorrelation characteristics of transverse blood flow using an intravascular ultrasound (IVUS) array catheter by means of computer modeling.
F.A. Lupotti, A.F.W. van der Steen
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In recent years, a new method to measure transverse blood flow, based on the decorrelation of the radio frequency (RF) signals has been introduced. We investigated the decorrelation characteristics of transverse blood flow using an intravascular ultrasound (IVUS) array catheter by means of computer modeling.
F.A. Lupotti, A.F.W. van der Steen
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Flow velocity measurements for pulsatile flow
Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 1988The inherent sensitivity of magnetic resonance imaging to motion makes it particularly well-suited as a noninvasive flow measurement modality. A pulse sequence which labels moving material by subjecting it to a pulse that inverts the longitudinal magnetization is discussed.
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Calculating Linear Flow Velocity from Volumetric Flow Rate
Cold Spring Harbor Protocols, 2010INTRODUCTIONIn chromatography, flow rates should be standardized for columns of different dimensions by expressing the flow rate as linear flow velocity (cm/h). This is defined as the volumetric flow rate (cm3/h) per unit cross-sectional area (cm2) of a given column. However, flow rates are usually measured as volumetric flow rates (mL/min).
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Journal of Hydraulic Engineering, 1983
Most of the equations that have been developed for relating velocity of a stream in a partly filled pipe to the slope and size of the stream use hydraulic radius (R) as the parameter for size. The equations using this parameter are poor representations of flow behavior when comparing different relative depths of flow, as Camp pointed out for the case ...
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Most of the equations that have been developed for relating velocity of a stream in a partly filled pipe to the slope and size of the stream use hydraulic radius (R) as the parameter for size. The equations using this parameter are poor representations of flow behavior when comparing different relative depths of flow, as Camp pointed out for the case ...
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Abstract This chapter reviews basic concepts in fluid dynamics that are useful to the practice of anesthesiology. Laminar flow occurs when fluids flow in an orderly fashion without mixing. Turbulent flow involves mixing within the fluid and creates additional resistance to flow. The Reynolds number equation describes factors that promote
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Velocity-Vorticity Patterns in Turbulent Flow
Physical Review Letters, 1985Direct numerical simulation of the Navier-Stokes equations is used for the investigation of local helicity fluctuations in plane Poiseuille (channel) and Taylor-Green vortex flows. It is shown that in regions of high dissipation, the cosine of the angle between velocity and vorticity is evenly distributed; in regions of low dissipation, the velocity ...
, Pelz +4 more
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Flow velocity measurement with ac gradients
Magnetic Resonance in Medicine, 1987AbstractTwo NMR experiments are described that use ac field gradients to measure flow velocities. Both experiments perform no spacial localization; instead, fluid velocity is converted to a resonance frequency shift. Thus, by Fourier transformation of a single FID or echo train the distribution of velocities is available. The first experiment uses only
J H, Walton, M S, Conradi
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American Journal of Physics, 1978
We point out and discuss a frequently misunderstood, overlooked, or disregarded relationship between the energy-momentum tensor and the velocity of energy flow.
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We point out and discuss a frequently misunderstood, overlooked, or disregarded relationship between the energy-momentum tensor and the velocity of energy flow.
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