Abstract:
An optical fiber based polymer core sensor includes an optical fiber having a core and an end having a cured polymer core affixed to the core of the optical fiber. The cured polymer core extends outward from the end of the optical fiber and has a diameter approximately equal to the core of the optical fiber. Note the cured polymer core can be substantially cylindrical, tapered or geometrically shaped. The optical fiber based polymer core sensor can be used to measure a temperature, measure a strain, measure a distance, measure a refractive index, detect or measure an analyte, detect a toxin, detect a biological agent, monitor a chemical process, or a combination thereof
Abstract:
An optical fiber sensor is provided for displacement measurement, pressure measurement, refractive index measurement, bio/chemical detection, and/or microscopy.
Abstract:
The condition of a structure using remote interrogation of a multi-state passive wireless antenna sensor that has a known resonant frequency when mounted on the structure. The passive wireless antenna sensor is connected to a remotely operated switching circuit that includes a photocell. An interrogation system transmits a series of radio frequency signals with sweeping frequencies around the known resonant frequency to the passive wireless antenna sensor, while simultaneously pulsing a laser to switch the passive wireless antenna sensor between a first state and a second state in which it is exposed to open-circuit or short-circuit conditions. A signal is reflected from the passive wireless antenna sensor in each of the first and second states, and a resonant frequency of the passive wireless antenna sensor is determined by normalizing the received signals to isolate the antenna mode.
Abstract:
A sensor, sensor assembly and a method of sensing, in which the sensor is in contact with a material or structure and the sensor directly measures one or more property changes in the material by means of light reflection and scattering using a reflective target.
Abstract:
Systems and methods for automatically determining the availability of resources, such as Internet advertising opportunities, are described herein. The systems and methods efficiently process bulk queries that specify multiple target values for at least one attribute associated with the resources, such bulk queries being useful for determining the availability of a wide variety of different resource types.
Abstract:
An optical fiber based polymer core sensor includes an optical fiber having a core and an end having a cured polymer core affixed to the core of the optical fiber. The cured polymer core extends outward from the end of the optical fiber and has a diameter approximately equal to the core of the optical fiber. Note the cured polymer core can be substantially cylindrical, tapered or geometrically shaped. The optical fiber based polymer core sensor can be used to measure a temperature, measure a strain, measure a distance, measure a refractive index, detect or measure an analyte, detect a toxin, detect a biological agent, monitor a chemical process, or a combination thereof.
Abstract:
A method of treating a subterranean formation penetrated by a wellbore includes preparing a treatment fluid with shear thinning, non-monotonic rheological properties, injecting the treatment fluid into the subterranean formation, and inducing shear rate softening phase transition in the treatment fluid. The non-monotonic rheology properties can be such that in the relationship between shear stress (σ) versus strain rate ({dot over (γ)}), where {dot over (γ)}1
Abstract:
An apparatus and method is provided for monitoring a condition of a structure using a passive wireless antenna sensor having a known resonant frequency when mounted on the structure. A series of radio frequency signals are transmitted with sweeping frequencies around the known resonant frequency to the passive wireless antenna sensor. The passive wireless antenna sensor includes a dielectric substrate disposed between an antenna pattern and a ground plane such that a change in the condition of the structure will cause a change in one or more characteristics of the passive wireless sensor. A signal is received from the passive wireless antenna sensor and a resonant frequency of the passive wireless antenna sensor is determined based on the received signal. The determined resonant frequency is then compared to the known resonant frequency, whereby a change in the resonant frequency indicates a change in the condition of the structure.
Abstract:
The condition of a structure using remote interrogation of a multi-state passive wireless antenna sensor that has a known resonant frequency when mounted on the structure. The passive wireless antenna sensor is connected to a remotely operated switching circuit that includes a photocell. An interrogation system transmits a series of radio frequency signals with sweeping frequencies around the known resonant frequency to the passive wireless antenna sensor, while simultaneously pulsing a laser to switch the passive wireless antenna sensor between a first state and a second state in which it is exposed to open-circuit or short-circuit conditions. A signal is reflected from the passive wireless antenna sensor in each of the first and second states, and a resonant frequency of the passive wireless antenna sensor is determined by normalizing the received signals to isolate the antenna mode.
Abstract:
An apparatus and method is provided for monitoring a condition of a structure using a passive wireless antenna sensor having a known resonant frequency when mounted on the structure. A series of radio frequency signals are transmitted with sweeping frequencies around the known resonant frequency to the passive wireless antenna sensor. The passive wireless antenna sensor includes a dielectric substrate disposed between an antenna pattern and a ground plane such that a change in the condition of the structure will cause a change in one or more characteristics of the passive wireless sensor. A signal is received from the passive wireless antenna sensor and a resonant frequency of the passive wireless antenna sensor is determined based on the received signal. The determined resonant frequency is then compared to the known resonant frequency, whereby a change in the resonant frequency indicates a change in the condition of the structure.