摘要:
Sensors, methods and systems detect physical effects (e.g., corrosion, erosion, scaling and/or oxidation) of a fluid in contact with a diaphragm associated with a sensor assembly. The diaphragm preferably exhibits a first mechanical response when initially placed into contact with a fluid and a second mechanical response different from the first mechanical response after exposure to the fluid for a predetermined period of time. A change in the diaphragm mechanical responses between at least the first and second mechanical responses is therefore indicative of physical effects on the diaphragm over time caused by the fluid in contact therewith. A mechanical response sensor is operatively associated with the diaphragm so as to measure the change in the diaphragm mechanical responses and thereby determine the physical effects over time of the fluid in contact with the diaphragm. In some embodiments, the diaphragm is actuated due to a pressure condition exerted by the fluid or in other embodiments the diaphragm is internally actuated. Internal actuation includes pneumatic, hydraulic or piezoelectric means for producing a mechanical response of the diaphragm. In one embodiment, therefore, fluid corrosivity may be sensed by bringing a sensor assembly having a pressure-actuated diaphragm into contact with a corrosive fluid, exerting a pressure condition on the diaphragm so as to cause the mechanical response of the diaphragm, measuring the diaphragm deflection or strain, and then deriving fluid corrosivity from the measured diaphragm mechanical response.
摘要:
A portion of a polarization maintaining (PM) optical fiber having two polarization states is analyzed. First and second spectral responses of the PM fiber portion are determined. In a preferred implementation, the spectral responses are determined using Optical Frequency Domain Reflectometry (OFDR). Each polarization state of the PM fiber portion has a corresponding spectral component in the first spectral response. First and second spectral analyses of the PM fiber portion are performed using the first and second spectral responses. Based on those spectral analyses of the PM fiber portion, a first physical characteristic affecting the PM fiber portion is determined that is distinct from a second different physical characteristic affecting the fiber portion. Example physical characteristics include temperature and strain. An output signal related to the first physical characteristics affecting the fiber portion is provided, e.g., for display, further processing, etc.
摘要:
Described herein are synthetically modified fullerene molecules, wherein the fullerene is preferably ellipsoid in shape with an equatorial band and two opposing poles, comprising an adduct at one or both poles, at least one adduct being a hydrophobic chemical moiety capable of anchoring the fullerene on or in a lipid membrane.
摘要:
A passive sensor that is located on or adjacent to a structure that can be used to monitor the affect of environment on a structure or coating that is used to protect the structure. The sensor includes a parasitic element that interacts with the environment and influences the intensity of the electromagnetic response between the inductive element of the sensor and the antenna of the interrogation reader device. The condition of the parasitic element is determined by the radio frequency interaction of the reader antenna and the inductive element of the sensor. The parasitic element condition correlates to the environmental severity, or corrosivity of the environment and damage to metallic structures or protective coatings. An integrated circuit within the sensor is capable of storing identification, time, material, and measurement information. The sensor and system of the present invention is useful for tracking and monitoring cumulate environmental damage to a structure.
摘要:
A calibration device is described for use in calibrating an ultrasonic pulse echo apparatus for detecting a moving object in a fluid, where the ultrasonic pulse echo apparatus includes an ultrasonic transducer and calibration circuitry. A connector has a first end for connecting with a first fluid conduit and a second end for connecting with a second fluid conduit. A cavity between the first and second ends permits the fluid containing the moving object from the first conduit to flow through the connector cavity to the second fluid conduit. A first calibration sphere is positioned relative to the connector for reflecting an ultrasonic pulse signal transmitted by the ultrasonic transducer. The reflected ultrasonic pulse signal is useable by the calibration circuitry to calibrate the ultrasonic pulse echo apparatus.
摘要:
The present invention is directed toward a self-decontaminating surface coating, which when cured has a partially hydrophobic surface. The coating comprises a polymeric coating resin which, when cured, is hydrophilic. The coating also comprises a biocide, a germinating agent, and a hydrophobic micro/nano particulate material. The coating is suitable for application to ceramics, metals, and polymer substrates. Articles coated with the coating of the present invention are resistant to spores.
摘要:
Light is coupled into two polarization modes of a waveguide, e.g., an optical fiber. The spectral response of Rayleigh backscatter in the waveguide segment for the two polarization modes is measured, e.g., using OFDR, OTDR, OLCR, etc. The autocorrelation of the spectral response is calculated. The spectral (wavelength) shift from a main autocorrelation peak to a side autocorrelation peak, corresponding to one of the two polarization modes of the waveguide segment, is determined. The spectral shift, corresponding to a beat length of the waveguide segment, is multiplied by an average index of refraction to determine a birefringence of the waveguide segment.
摘要:
The present invention is directed towards an acoustic concealed item detector and related methods for detection using acoustics. In an illustrative embodiment, a multi-frequency ultrasonic wave generator generates in a gaseous medium at least first and second ultrasonic waves. The multi-frequency ultrasonic wave generator is arranged such that in operation, the first ultrasonic wave and the second ultrasonic wave mix in a prescribed mixing zone to produce a difference-frequency acoustic wave. A receiver sensor detects the difference-frequency acoustic wave and produces corresponding electromagnetic signals. The electromagnetic signals are processed by a system processor and signals indicative of concealed items are identified. Preferably the ultrasonic waves are focused to a small prescribed mixing zone. Parametric and multi-transducer embodiments are disclosed.
摘要:
Integral fiber optic-based condition sensors detect conditions of a composite structure, e.g., a coated wire assembly so as to detect damage or conditions that may damage the same. Preferably, at least one optical fiber sensor having a plurality of Bragg gratings written into the fiber at spaced-apart locations along its axial length is integrated into the electrical insulator coating of a wire, wire bundle or wiring harness. The fiber optic sensor may thus be employed to measure the environmental loads on the electrical wiring including stresses from bending, axial loading, pinch points, high temperature excursions and chemical damage. The system is capable of detecting and locating transient conditions that might cause damage to a wiring system or permanent changes in state associated with damage events. The residual stress in the electrical insulator coating of a wire, wire bundle, or wiring harness are used to monitor the evolution of damage by wear or chaffing processes. Detected stress relief on one or more Bragg gratings will thus be indicative of damage to the insulator coating on the conductor. As such, the magnitude of such stress relief may be detected and used as an alert that the wire insulation is damaged to an unsafe extent.
摘要:
Light is coupled into two polarization modes of a waveguide, e.g., an optical fiber. The spectral response of Rayleigh backscatter in the waveguide segment for the two polarization modes is measured, e.g., using OFDR, OTDR, OLCR, etc. The autocorrelation of the spectral response is calculated. The spectral (wavelength) shift from a main autocorrelation peak to a side autocorrelation peak, corresponding to one of the two polarization modes of the waveguide segment, is determined. The spectral shift, corresponding to a beat length of the waveguide segment, is multiplied by an average index of refraction to determine a birefringence of the waveguide segment.