University of Missouri

Jinglu Tan

Limin Wang

Nilesh Salvi

A system and method for measuring one or more viscoelastic properties of a material under measurement is disclosed. The system includes an emitter-observer transducer pair separated by the material. A signal processing assembly is operable to (i) apply a plurality of excitation signals to the emitter transducer, wherein each of the excitation signals comprises a continuous-wave sinusoidal waveform, (ii) record a plurality of output signals at the observer transducer, wherein each of the output signals corresponds to one of the excitation signals, (iii) analyze the output signals to measure the sound speed of the material, and (iv) determine the viscoelastic properties of the material under measurement by optimizing the parameters of an infinite echo model. The system provides a non-destructive approach for in-situ measurement of viscoelastic material properties.

System and method for in-situ measurement of viscoelastic material properties using continuous-wave ultrasound

A pressure regulator apparatus and method for controlling the pressure in a pressure system is disclosed. The pressure regulator broadly includes a pressure transducer and a regulator control circuit. The pressure transducer measures the pressure of the pressure system, and the regulator control circuit controls the pressure in the pressure system in response to the pressure reading of the pressure transducer. The regulator control circuit compares the measured pressure to a predetermined set-point value for maintaining the pressure within a predetermined optimal pressure range.

Vacuum regulator

A servovalve includes a casing presenting an inlet and an outlet, and a primary valve supported on the casing and including a valve plug that is movable between a closed position blocking flow through the casing, and a plurality of open positions in which the valve plug presents a restriction of variable size for varying the flow. A diaphragm supports the valve plug and includes a first side proximal to the plug and a second side remote from the plug. A control chamber is provided on the first side of the diaphragm, and is connected to the inlet by a pilot inlet passage and to the outlet by a pilot outlet passage. A pilot valve controls the flow of fluid through the pilot outlet passage, and includes a control plug that is movable between a closed position in which the control plug blocks the pilot outlet passage, and a plurality of open positions in which the control plug presents a restriction of variable size within the pilot outlet passage for varying the flow between the control chamber and the outlet. A solenoid moves the control plug between the closed and open positions, and includes an electromagnetic coil, an axially shiftable core on which the control plug is supposed, and a spring assembly for supposing the core within the coil so that the position of the core relative to the coil is established by the force exerted on the core by the electromagnetic field around the coil acting in opposition to the spring assembly.

Growing community of inventors

Columbia, MO, United States of America

Jinglu Tan