A Hydraulic Study of Venous Valve Closure
The functions of the veins is to convey blood from the periphery to the heart. The distribution and transportation of blood between different parts of the body is regulated by a host of...
Systolic Anterior Motion of the Mitral Valve: In Vitro Flow Studies
Using an in-vitro approach, the goal of this study was to determine and to characterize the mechanism of systolic anterior motion of the mitral valve in obstructive hypertrophic cardiomyopathy....
Leakage Characteristics of the St. Jude Heart Valve
The requirement for anticoagulant therapy in patients implanted with mechanical heart valve prostheses is well known. A plausible explanation for this requirement is that the leakage flow...
Lumped Parameter Model for the Dynamics of the Pulmonary Circulation
The pulmonary circulation is a low pressure system such that respiration has an important effect on pulmonary hemodynamics and has to be taken into account when predicting its behavior....
Numerical Simulations of Diastolic Flow Patterns in a Model Left Ventricle with Varying Degrees of Mitral Stenosis
Blood flow patterns in the left ventricle are undoubtedly influenced by the physical and mechanical state of the natural mitral valve apparatus or the geometry of an artifical valve replacement....
On-Orbit Chipless Cutting and Tube Welding in Space Station Freedom
Micro-gravity and strict environmental constraints of the laboratory, Habitation and other manned structures which comprise Space Station Freedom demand investigation into innovative processes...
Aeration Using the Howell-Bunger Valve
Computer Modeling as a Tool for Selecting Appropriate Air Valves for Pipeline Surge Protection
Waterhammer in water or wastewater pipelines is caused by events such as a pump power failure and can have potentially damaging effects on the pipeline or pipeline hardware. In particular,...
Simulation of Blood-Heart Interaction: Validation of Approach
An existing pressure correction method to model unsteady flow with arbitrarily moving boundaries has been adapted to simulate the interaction of three-dimensional blood flow with a mitral...
Pressure Control Studies for PG&E's 20 MW Grizzly Hydroelectric Project
The Pacific Gas and Electric Company's Grizzly Hydroelectric Project consists of a single 20 MW Francis turbine under 700 feet head located near the existing Bucks Creek Project....
Rocky Mountain Pump-Turbines and Related Mechanical Equipment
The Rocky Mountain powerplant will have three reversible, single stage, vertical shaft pump-turbine units, each having a maximum output of 321 MW generating and a maximum pumping capacity...
TransAct: An Interactive Transient Analysis Program for Pipelines
The program TransAct is designed to analyze a wide range of transient responses that may have been caused by a complex combination of control actions. For example, there may be the simultaneous...
Model Study of a Hurricane Surge Barrier Gate Valve
Physical model studies were conducted to determine the hydraulic performance of a unique vertical butterfly-gated structure. These studies were also used to determine the torque on the...
Evaluation of Automatic Earthquake Shutoff Valve Performance and Recommendations for Future U.S. Standards
Increasing interest of local and state government has developed in recent years regarding legislation requiring automatic shutoff valves for natural gas lines as well as lines containing...
On Reliability of Mechanical Logics and Its Application
Recently, most of logical circuits are understood to consist of electrical components and wiring, however, we are still using various types of mechanical logics at the end of the safety-related...
Valve Control to Avoid Column Separation in a Pipe
Maximum pressures in a pipeline can be reduced significantly by closing the valve in an optimal manner. Such an optimal valve closure policy may result in some situations in minimum pressures...
Guard Gate Tests at Tieton Dam
The emergency gate hoist system on the guard gates at Tieton Dam, near Yakima, Washington, was tested as part of the United States Bureau of Reclamation Safety Evaluation of Existing Dams...
Study on Pneumatic Wave Power Conversion System with the Water Valve Rectifier
We experimentally and theoretically studied the energy conversion characteristics on a new type of wave power conversion system with water valves. The hydraulic model experiment was performed...
Locating and Sizing Air Release Valves on Irrigation Systems
This writing is directed to persons involved in irrigation systems and describes the usage of air release and vacuum valves. Principles described are applicable to many other piping systems,...
Hydraulic Transient Analysis of High-Head Hydropower Project
An iterative computer simulation procedure called LIQT (Liquid Transient), which performs simulations of hydraulic transients in closed conduit hydro-power systems, is used to estimate...
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