Stevens Institute of Technology

Other

USA As Represented by Secretary of the Navy

Baker Hughes Corporation

Dimitri M Donskoy

Alexander M Sutin

Nikolay Sedunov

Douglas J Patterson

Vladimir Dubinsky

Michael L Epstein

Xiao Ming Tang

Joseph Gregory Barolak

Alexei Bolshakov

Benjamin A Cray

Stephen C Butler

Jaime A Siegel

Jason E Gaudette

Edward A Whittaker

A linear transducer is connected to a first flexible member that has a first elongated shape with a first minor axis and a first major axis perpendicular to each other. This connects the linear transducer to opposite portions of the first flexible member along the first major axis. A second flexible member having an elongated shape with a second minor axis and a second major axis is provided. The second flexible member is connected to the first flexible member such that portions on the second major axis are joined to move with portions of the first flexible member on the first minor axis. Operation of the linear transducer multiplies displacements of the second flexible member relative to those of the transducer.

High amplification flextensional transduction and devices

The invention as disclosed is a fiber optic interferometric directional acoustic density sensor that increases the directionality of a vector sensor that is much smaller in size than the wave length of an acoustic wave. This is accomplished through the use of second order directionality by measuring the acoustic fluctuations of fluid density at a point, wherein the acoustic density fluctuations are determined according to the principles of fluid compressibility and conservation of mass using a density fluctuation measuring apparatus that restricts two of the three vector components of the particle velocity of the acoustic wave and that employs a laser interferometer to measure the fluid density fluctuation along the remaining vector component.

Directional acoustic density sensor

An acoustic vector sensor mounted in a housing is provided for measuring ultra low frequency acoustic wave particle velocities in a liquid, comprising a horn for amplifying the acoustic wave particle velocities, and a neutrally buoyant object supported in a liquid contained in the horn. The neutrally buoyant object, in reacting to the amplified acoustic wave particle velocities, produces displacements that are sensitively measured.

Ultra low frequency acoustic vector sensor

A method useful for evaluating the presence and/or the quality of the cement bond of a downhole tubular. The method involves measuring radial resonance modes of the tubular, and comparing those measured values to the unbound tubular resonant values of a calibration ring. For a well bonded tubular, the measured radial resonance should be greater than that of the unbound tubular calibration ring. In regions where a fluid, such as water surrounds the outside of the tubular, or the cement is otherwise not bonded to the outer surface of the tubular, the measured response should be less than the calibrated response. The calibration ring should have the same diameter, wall thickness, and be made of the same material as the tubular.

Casing resonant radial flexural modes in cement bond evaluation

A method and apparatus () is provided which employs phase or amplitude modulated electromagnetic probing waves () (in optical or microwave frequency ranges or both) emitted toward a vibrating object (). The optical and/or microwave probing signals () remotely irradiate an object () of interest. The object () reflects and/or scatters the probing wave () toward a receiver (). The reflected/scattered modulated signal () is received with a remote sensor (receiver) (). Vibration causes additional phase modulation to the probing wave (). At the receiving end, the signal is demodulated to extract and analyze the vibration waveform (). The present invention can be utilized for nondestructive testing, monitoring of technological processes, structural integrity, noise and vibration control, mine detection, etc.

Method and apparatus for remote measurement of vibration and properties of objects

A device and method for detecting the presence of living organisms in a structure or behind a wall or partition utilizes a microwave or radio-frequency one or more transceivers which generate separate and distinct interrogating signals and receives separate and distinct signals reflected from a structure and living organisms within it. The reflected signals received by each of the transceivers are processed, for instance by a microprocessor, so as to provide output signals that indicate the presence or absence of a living organism in the structure or behind wall or partition. The microprocessor distinguishes and differentiate signals from different living organisms and from false indication of the presence of living organisms, thereby enabling the detection of living organisms despite the existence of motion signals caused by non-living organism motion. Similarly, the device can distinguish between the biological characteristics, such as respiration rates, of targets to determine if the targets are of the type sought, for example, human targets as opposed to pets or insects.

Device and method for detecting localization, monitoring, and identification of living organisms in structures

A device and method for detecting the presence of insects in a structure utilize a plurality of transceivers, each of which generates separate and distinct microwave signals and receives separate and distinct signals reflected from a structure being tested. The reflected signals received by each of the transceivers are processed, for instance by a microprocessor, so as to provide output signals that indicate the presence or absence of insects in the structure. If most or all of the transceivers receive positive signals indicative of the possible presence of insects in the structure, which is a false indication of the presence of insects, the microprocessor distinguishes this false indication from an actual indication of the presence of insects, thereby enabling the detection of insects despite the existence of motion signals caused by non-insect motion.

Device and method for detecting insects in structures

In order to detect buried compliant objects such as land mines and pipes, an acoustic signal is directed into the ground to excite vibration of a buried compliant object. A probing signal is also directed into the ground toward the vibrating object, and the probing signal is modulated and reflected by the vibrating object. The modulated, reflected probing signal is processed to determine therefrom the presence of the buried compliant object.

Method and apparatus for acoustic detection of mines and other buried man-made objects

The invention relates to a method and apparatus for nondestructive testing and evaluation of materials and mechanical structures to determine their integrity reducing contact-type flaws such as cracks, fractures, delamination, unbondings, etc. and also presence of ice on a structure. The invention employs an ultrasonic probing signal and a low frequency vibration applied to a structure tested. In a structure without flaws or ice, these signals propagate independently without any interaction. If the structure contains a defect or ice thereon, the vibration varies the contact area of the defect or ice/structure interface, modulating the phase and amplitude of the higher frequency ultrasonic probing signal passing through the structure. In the frequency domain the result of this modulation manifests itself as sideband spectral components with respect to frequency of the probe wave. This can be considered as a new signal generated by a defect, so that the defect can be detected more easily when such a signal is observed. There are three modes of detection including, vibro-modulation, impact-modulation and self-modulation. The location of defects can be determined in two modes. In a first mode defect is located by moving the low frequency signal about the structure and triggering the high frequency signal immediately after the low frequency signal. Defects can be located in a second mode with a sequence of short burst high frequency signal and a signal-processing algorithm which selects the sequences reflected from various areas of the tested structure. A defect can be quantitatively analyzed by sweeping the high frequency signal over a defined frequency range and measuring, averaging and normalizing the amplitudes of the side bands.

Method and apparatus for acoustic detection and location of defects in structures or ice on structures

A device which employs an acoustic signal having one or more frequencies for penetrating into ground, water, or sediments and vibrating a compliant buried object is provided. When these acoustic signals encounter an acoustically compliant object such as a mine, the acoustic signals vibrate the compliant object, leading to a vibration of the compliant object against the boundaries of the surrounding medium such as ground sediment, creating a nonlinear distortion of the probing signal including the generation of harmonics and acoustic waves with combination frequencies (nonlinear signals). These nonlinear vibrating signals are received from the surface by a sensor. The amplitude of the measured nonlinear signals indicates the presence of an acoustically compliant object such as a mine.

Method and apparatus for acoustic detection of mines and other buried

Non-invasive technique for bone mass measurement

Low frequency underwater acoustic radiator apparatus includes an air-trapping chamber with a lower portion open to the water, characterized by a mean density higher than that of water. A closed, rigid float element having a mean density equal to or lower than that of water is disposed with a selected loose fit within the chamber. When the chamber and float combination are submerged in water with a substantially vertical orientation of the chamber, the float element floats within the chamber, with the trapped air functioning as a spring coupling. A vibromotive element is coupled to the float element or the chamber element to induce oscillation of the coupled element. The coupling of the chamber and the float by the air spring converts the dipole oscillation of the oscillating element into a monopole pulsation suitable for a low frequency underwater sound radiator. The resonant frequency of the assembly can be changed by altering the volume of air in the chamber, or by changing the depth at which the device is submerged.

Growing community of inventors

Hoboken, NJ, United States of America

Dimitri M Donskoy