Get 63-2019: State Primary Special Standard of Units of Mass and Volume of Liquid in a Flow and of Mass and Volume Flow Rates of a Liquid

We extend a recent theory for steady uniform gravity-driven flow of a highly concentrated granular-fluid mixture over an erodible bed between frictional sidewalls. We first include angles of inclination greater than the angle of repose of the particles; then, we introduce a boundary condition for flow over a rigid bumpy bed. We compare the predictions of the resulting theory with the volume flow rates, depths and angles of inclination measured in the experiments on dry and variously saturated flows over rigid and erodible boundaries. Finally, we employ the resulting theory, with the assumption that the flow is shallow, to solve, in an approximate way, for the variation of height and average velocities along a steady non-uniform inclined flow of a granular-fluid mixture that moves over a rigid bumpy bed. The solutions exhibit features of the flow seen in the experiments – for example, a dry bulbous snout in advance of the fluid, whose length increases with increasing number of the particles and that disappears with increasing velocity – for which satisfactory explanations were lacking.

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Exergy Analysis of an Air Conditioning System Using Air-Cooled Condenser at Different Ambient Conditions with Different Volume Flow Rates of Air

Proceedings of International Conference in Mechanical and Energy Technology - Smart Innovation, Systems and Technologies ◽

10.1007/978-981-15-2647-3_55 ◽

2020 ◽

pp. 597-605

Author(s):

Taliv Hussain ◽

Adnan Hafiz ◽

Akramuddin

Keyword(s):

Air Conditioning ◽

Exergy Analysis ◽

Volume Flow ◽

Ambient Conditions ◽

Air Conditioning System ◽

Flow Rates

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Validation of a third-generation Doppler system for studies of detailed aortic flow

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1984.247.5.h847 ◽

1984 ◽

Vol 247 (5) ◽

pp. H847-H856

Author(s):

J. A. Rumberger ◽

C. F. Fastenow ◽

D. L. Laughlin ◽

M. L. Marcus

Keyword(s):

Velocity Profile ◽

Volume Flow ◽

Aortic Diameter ◽

Doppler Velocity ◽

Third Generation ◽

Flow Rates ◽

Doppler System ◽

Aortic Hemodynamics

A multigated, third-generation Doppler velocity system has been developed and validated for detailed studies of aortic hemodynamics. The Doppler system employs a single 3-mm, 5-MHz crystal applied to the aorta at a fixed angle with respect to the flow axis and is capable of measuring velocity profile, blood vessel diameter, and integrated volume flow on a continuous, real-time basis. This represents a major developmental advance over existing first-generation, continuous-wave and second-generation, single-gated pulsed Doppler systems. Validation studies have been performed in vitro and in dogs. Aortic diameter was measured simultaneously with the volumetric Doppler system and with sonomicrometer probes. During changes in aortic diameter between 8 and 18 mm (n = 18), produced by temporary pulmonary artery occlusion or epinephrine infusion, quantitative agreement between the Doppler and sonomicrometer probes was found (r = 0.96). Velocity profile measurements and axial velocity values made with the Doppler system compared favorably with hot-film anemometry studies in vitro and in vivo. Although the current system is nondirectional, measurements of phasic aortic volume flow and absolute-time-averaged changes in flow rates showed an excellent correlation with chronically placed electromagnetic flow probes over a broad range of flow rates in vivo (1-5 l/min, n = 36, r = 0.95). This third-generation Doppler system should prove useful in clinical and research studies of detailed aortic hemodynamics.

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Unsteady Unidirectional MHD Flow of Voigt Fluids Moving between Two Parallel Surfaces for Variable Volume Flow Rates

Journal of Applied Mathematics ◽

10.1155/2012/869357 ◽

2012 ◽

Vol 2012 ◽

pp. 1-12

Author(s):

Wei-Fan Chen ◽

Hsin-Yi Lai ◽

Cha'o-Kuang Chen

Keyword(s):

Velocity Profile ◽

Volume Flow Rate ◽

Linear Acceleration ◽

Mhd Flow ◽

Volume Flow ◽

Magnetic Field Effects ◽

Piston Motion ◽

Transform Method ◽

Flow Rates ◽

Parallel Surfaces

The velocity profile and pressure gradient of an unsteady state unidirectional MHD flow of Voigt fluids moving between two parallel surfaces under magnetic field effects are solved by the Laplace transform method. The flow motion between parallel surfaces is induced by a prescribed inlet volume flow rate that varies with time. Four cases of different inlet volume flow rates are considered in this study including (1) constant acceleration piston motion, (2) suddenly started flow, (3) linear acceleration piston motion, and (4) oscillatory piston motion. The solution for each case is elaborately derived, and the results of associated velocity profile and pressure gradients are presented in analytical forms.

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Dynamic alterations in cerebral, celiac and renal flows resulting from ascending aorta, subclavian artery and femoral artery cannulations of extracorporeal devices

Perfusion ◽

10.1177/0267659117706606 ◽

2017 ◽

Vol 32 (7) ◽

pp. 561-567 ◽

Cited By ~ 2

Author(s):

Sahin Iscan ◽

Habib Cakir ◽

Bortecin Eygi ◽

Ismail Yurekli ◽

Koksal Donmez ◽

...

Keyword(s):

Blood Flow ◽

Cardiac Output ◽

Femoral Artery ◽

Extracorporeal Circulation ◽

Ascending Aorta ◽

Volume Flow ◽

Roller Pump ◽

Flow Rates ◽

Abdominal Organs ◽

Cannulation Site

Introduction: The aim of this study was to assess the relationships among cardiac output, extracorporeal blood flow, cannulation site, right (RCa) and left carotid (LCa), celiac (Ca) and renal artery (Ra) flows during extracorporeal circulation. Methods: A mock circulatory circuit was assembled, based on a compliant anatomical aortic model. The ascending aorta, right subclavian and femoral artery cannulations were created and flow was provided by a centrifugal pump (Cp); cardiac output was provided by a roller pump (Rp). Five volume flow rates were tested. The Rp was set at 4 L/min with no Cp flow (R4-C0) and the basic volume flow rates of the vessels were measured. The flow of the Cp was increased while the Rp flow was decreased for other measurements; R3-C1, R2-C2, R1-C3 and R0-C4. Measurements were repeated for all cannulation sites. Results: The RCa flow rate at R4-C0 was higher compared to the R3-C1, R2-C2, R1-C3 and R0-C4 RCa flows with subclavian cannulation. The RCa flow decreased as the Cp flow increased (p<0.05). The RCa flow with ascending aortic and femoral cannulation was higher compared to subclavian cannulation. Higher flows were obtained with subclavian cannulation in the LCa compared to the others (p<0.05). R4-C0 Ca and Ra flows were higher compared to other Ca and Ra flows with femoral cannulation. Ca and Ra flows decreased as Cp flow increased. Flows of the Ca and Ra with ascending and subclavian cannulations were not lower compared to the R4-C0 flow (p<0.05). Conclusion: This study shows that prolonged extracorporeal circulation may develop flow decrease and ischemia in cerebral and abdominal organs with both subclavian and femoral cannulations.

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Effects of Arterial Pco2 and Cerebrospinal Fluid Volume Flow Rate Changes on Choroid Plexus and Cerebral Blood Flow in Normal and Experimental Hydrocephalic Cats

Journal of Cerebral Blood Flow & Metabolism ◽

10.1038/jcbfm.1983.53 ◽

1983 ◽

Vol 3 (3) ◽

pp. 369-375 ◽

Cited By ~ 13

Author(s):

S. Nakamura ◽

G. M. Hochwald

Keyword(s):

Blood Flow ◽

Cerebrospinal Fluid ◽

Cerebral Cortex ◽

Choroid Plexus ◽

Flow Rate ◽

Volume Flow Rate ◽

Volume Flow ◽

Brain Blood Flow ◽

Choroidal Blood Flow ◽

Flow Rates

The effect of changes in brain blood flow on cerebrospinal fluid (CSF) volume flow rates, and that of changes in CSF volume flow rates on brain blood flow were determined in both normal and kaolin-induced hydrocephalic cats. In both groups of cats, blood flow in grey and white matter, cerebral cortex, and choroid plexus was measured with 105Ru microspheres during normocapnia, and again with 141Ce microspheres after arterial Pco2 was either increased by 300% or decreased by 50%. Blood flow measurements were also made during perfusion of the ventricular system with mock CSF and repeated during perfusion with anisosmotic mannitol solutions to alter CSF volume flow rate. In 30 normal and 26 hydrocephalic cats, blood flow to the cerebral cortex, white matter, and choroid plexus was similar; only blood flow to the caudate nucleus was greater in normal cats. The weight of the choroid plexus from hydrocephalic cats decreased by 17%. Blood flow in the choroid plexus of all cats decreased by almost 50% following hypercapnia or hypocapnia, without a change in the CSF volume flow rate. There was no change in cerebral or choroidal blood flow when CSF volume flow rate was either increased by 170% or decreased by 80%. These results suggest that choroid plexus blood flow does not limit or affect the volume flow rate of CSF from the choroid plexus. CSF volume flow rate can be altered without corresponding blood flow changes of the brain or choroid plexus. Choroid plexus blood flow and the reactivity of both brain and choroidal blood flow to changes in arterial Pco2 were not affected by the hydrocephalus. The lower CSF formation rate of hydrocephalic cats can be attributed in part to the decrease in the mass of choroid plexus tissue.

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Echocardiographic volume flow and stenosis severity measures with changing flow rate in aortic stenosis

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1993.265.5.h1734 ◽

1993 ◽

Vol 265 (5) ◽

pp. H1734-H1743 ◽

Cited By ~ 2

Author(s):

I. G. Burwash ◽

A. D. Forbes ◽

M. Sadahiro ◽

E. D. Verrier ◽

A. S. Pearlman ◽

...

Keyword(s):

Aortic Stenosis ◽

Flow Rate ◽

Progressive Disease ◽

Volume Flow ◽

Pressure Gradients ◽

Disease Evolution ◽

Flow Rates ◽

Stenosis Severity ◽

Valvular Aortic Stenosis ◽

Valve Area

The anatomy of degenerative valvular aortic stenosis has been poorly represented in animal models, limiting the evaluation of noninvasive echo-Doppler measures of transvalvular volume flow rate and stenosis severity during progressive disease evolution or under conditions of changing volume flow rates. To study these issues, chronic valvular aortic stenosis, characterized by stiff leaflets without commissural fusion, was created in nine adult mongrel dogs by suturing pericardial covered Teflon-felt pads into the sinuses of Valsalva below the coronary ostia during hypothermic cardiac arrest. In the eight surviving dogs, echo-Doppler examinations were performed weekly for up to 8 wk postoperatively. Simultaneous invasive micromanometer pressure data were collected at 2-wk intervals in all subjects, with simultaneous ascending aortic transit time-volume flow measurement in four subjects. Volume flow rates were altered with saline and dobutamine infusions during invasive studies for comparison of echo-Doppler and invasive pressure gradients, volume flow, and valve areas. Serial echo-Doppler follow-up (39 +/- 11 days) demonstrated that, from baseline to final study, mean transvalvular pressure gradient increased (4 +/- 1 to 38 +/- 7 mmHg, P = 0.001), continuity equation aortic valve area decreased (2.06 +/- 0.18 to 0.54 +/- 0.04 cm2, P < 0.0001), and progressive left ventricular hypertrophy developed (62 +/- 6 to 114 +/- 9 g, P = 0.0003). Echo-Doppler and invasive data correlated well for measures of transvalvular pressure gradients (n = 98, maximum instantaneous gradient r = 0.95, mean gradient r = 0.91), volume flow (n = 75, stroke volume r = 0.86, cardiac output r = 0.86), and valve area (n = 73, r = 0.73) despite acute alterations in volume flow and progressive disease evolution. This chronic canine model, with anatomy and hemodynamics similar to clinical degenerative valvular aortic stenosis, should provide a valuable tool for investigating clinically relevant new measures of stenosis severity with use of invasive or noninvasive techniques.

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Optimization of the Process of Reproducing the Units of Mass and Volume of Liquid in Flows, and Mass and Volume Flow Rates of Liquid for Calibration Units with Weighing Devices

Measurement Techniques ◽

10.1007/s11018-020-01763-7 ◽

2020 ◽

Vol 63 (2) ◽

pp. 140-144

Author(s):

R. A. Korneev ◽

A. R. Tukhvatullin ◽

V. A. Fafurin ◽

R. R. Nigmatullin ◽

A. V. Shchelchkov

Keyword(s):

Volume Flow ◽

Flow Rates

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