Abstract: A method may comprise operations for expanding a cement mixture with an alkali-silica reaction. The method may include positioning a cement mixture around a casing string downhole in a wellbore. The cement mixture may include a cement material and a silica material. The method may include curing the cement material to cause the cement material to contract. The silica material and alkali in the cement material may undergo an alkali-silica reaction to produce a gel that expands the cement mixture. The rate of expansion of the cement mixture from the gel may be equal to or greater than the rate of contraction of the cement mixture from curing.

Abstract: A method of fabricating a multilayer circuit board is provided which includes forming a layer of a the multilayer circuit board with an internal clearance region having a modified voltage-to-ground clearance of conductive material adjacent to an aperture of the multilayer circuit board. The modified voltage-to-ground clearance of conductive material is based on a configuration of a connector pin to be press-fit connected within the aperture of the multilayer circuit board, and the internal clearance region is enlarged in a direction of greatest normal force outward from the aperture with insertion of the connector pin into the aperture.

Abstract: A battery-powered supplemental alert generator is disclosed that is adapted to be mounted in close proximity to, such as within 3 or 4 feet of, a conventional smoke, heat and/or fire detector/alert device. The supplemental alert generator operates in a relatively low power mode while listening for the nearby detector/alert device to generate a standard audible alert signal. Upon detecting that a monitored sound level has reached a particular threshold, the supplemental alert generator enters into a higher power analysis mode in which it analyzes the detected signal to assess whether it is an audible alert signal. If an audible alert signal is detected, the supplemental alert generator generates one or more supplemental alert signals, such as a 520 Hz audible square wave signal. The supplemental alert generator may be used to retrofit a house, hotel, or other building to comply with new standards or to otherwise increase the effectiveness of the existing detection/alert system.

Abstract: Various inventive features are disclosed for efficiently generating regulation-compliant audible alerts, including but not limited to 520 Hz square wave alert/alarm signals, using an audio speaker. One such feature involves the use of a non-linear amplifier in combination with a voltage boost regulator to efficiently drive the audio speaker. Another feature involves speaker enclosure designs that effectively boost the output of the audio speaker, particularly at relatively low frequencies. Some of the disclosed speaker enclosure designs rely on an interference effect and/or a resonance effect to transfer energy from higher-order harmonics downward to the fundamental frequency and lower-order harmonics. These and other features may be used individually or combination in a given alarm-generation device or system to enable regulation-compliant audible alerts to be generated using conventional batteries, such as AA alkaline batteries.

Abstract: A battery-powered supplemental alert generator is disclosed that is adapted to be mounted in close proximity to, such as within 3 or 4 feet of, a conventional smoke, heat and/or fire detector/alert device. The supplemental alert generator operates in a relatively low power mode while listening for the nearby detector/alert device to generate a standard audible alert signal. Upon detecting that a monitored sound level has reached a particular threshold, the supplemental alert generator enters into a higher power analysis mode in which it analyzes the detected signal to assess whether it is an audible alert signal. If an audible alert signal is detected, the supplemental alert generator generates one or more supplemental alert signals, such as a 520 Hz audible square wave signal. The supplemental alert generator may be used to retrofit a house, hotel, or other building to comply with new standards or to otherwise increase the effectiveness of the existing detection/alert system.

Abstract: Various inventive features are disclosed for efficiently generating regulation-compliant audible alerts, including but not limited to 520 Hz square wave alert/alarm signals, using an audio speaker. One such feature involves the use of a non-linear amplifier in combination with a voltage boost regulator to efficiently drive the audio speaker. Another feature involves speaker enclosure designs that effectively boost the output of the audio speaker, particularly at relatively low frequencies. These and other features may be used individually or combination in a given alarm-generation device or system to enable regulation-compliant audible alerts to be generated using conventional batteries, such as AA alkaline batteries. Various examples of efficiently generated regulation-compliant audible alerts and further enhancing such audible alerts by utilizing speaker enclosure designs are provided.

Abstract: Described herein are devices and systems that transmit data from a first device using an ultrasonic digital modem to a second device that receives the ultrasonic signal and can interpret the ultrasonic signal. The second device may be a telecommunications device such as a smartphone running an ultrasonic digital modem receiver application. In particular, devices, systems and methods for encoding and transmitting an ultrasonic signal that includes both digital (e.g., FSK) and analog signal components. Such hybrid ultrasonic signals may efficiently and reliably transmit information, and particularly biological information. Also described herein are devices, systems and methods for securely transmitting ultrasonic signals using encryption keys that may be read by the receiving device using a separate (e.g., non-ultrasound modality) from the transmitting device.

Abstract: Various inventive features are disclosed for efficiently generating regulation-compliant audible alerts, including but not limited to 520 Hz square wave alert/alarm signals, using an audio speaker. One such feature involves the use of a non-linear amplifier in combination with a voltage boost regulator to efficiently drive the audio speaker. Another feature involves speaker enclosure designs that effectively boost the output of the audio speaker, particularly at relatively low frequencies. Some of the disclosed speaker enclosure designs rely on an interference effect and/or a resonance effect to transfer energy from higher-order harmonics downward to the fundamental frequency and lower-order harmonics. These and other features may be used individually or combination in a given alarm-generation device or system to enable regulation-compliant audible alerts to be generated using conventional batteries, such as AA alkaline batteries.

Abstract: A battery-powered supplemental alert generator is disclosed that is adapted to be mounted in close proximity to, such as within 3 or 4 feet of, a conventional smoke, heat and/or fire detector/alert device. The supplemental alert generator operates in a relatively low power mode while listening for the nearby detector/alert device to generate a standard audible alert signal. Upon detecting that a monitored sound level has reached a particular threshold, the supplemental alert generator enters into a higher power analysis mode in which it analyzes the detected signal to assess whether it is an audible alert signal. If an audible alert signal is detected, the supplemental alert generator generates one or more supplemental alert signals, such as a 520 Hz audible square wave signal. The supplemental alert generator may be used to retrofit a house, hotel, or other building to comply with new standards or to otherwise increase the effectiveness of the existing detection/alert system.

Abstract: Various inventive features are disclosed for efficiently generating regulation-compliant audible alerts, including but not limited to 520 Hz square wave alert/alarm signals, using an audio speaker. One such feature involves the use of a non-linear amplifier in combination with a voltage boost regulator to efficiently drive the audio speaker. Another feature involves speaker enclosure designs that effectively boost the output of the audio speaker, particularly at relatively low frequencies. These and other features may be used individually or combination in a given alarm-generation device or system to enable regulation-compliant audible alerts to be generated using conventional batteries, such as AA alkaline batteries. Various examples of efficiently generated regulation-compliant audible alerts and further enhancing such audible alerts by utilizing speaker enclosure designs are provided.

Abstract: Medical sensing devices and systems that transmit digital data from a first device via an ultrasonic digital modem to a receiver such as a smartphone. Methods of transmitting digital biological data by ultrasound are also described.

Abstract: A signal processing system and associated methods are disclosed for reliably detecting audible alert signals, such as Temporal-3 and Temporal-4 alert signals generated by commercially available smoke, fire, and carbon monoxide detectors. The system and methods are capable of detecting audible alert signals of different intensities in the presence of dynamic background environment (e.g., television programming, music, noise, and the like). The signal processing system and methods may, in some embodiments, be incorporated into a bedside or other unit that generates a supplemental alert signal capable of alerting individuals who might not otherwise respond to the audible alert signal, such as individuals who are asleep, hearing impaired, or intoxicated.

Abstract: A signal processing system and associated methods are disclosed for reliably detecting audible alert signals, such as Temporal-3 (or Code-3) and Temporal-4 (or Code-4) alert signals generated by commercially available smoke, fire, and carbon monoxide detectors. The system and methods are capable of detecting audible alert signals of different intensities in the presence of dynamic background environment (e.g., television programming, music, noise, and the like). The system and methods are capable of detecting audible alert signals generated by far away smoke, fire, and carbon monoxide detectors. The signal processing system and methods may, in some embodiments, be incorporated into a bedside or other unit that generates a supplemental alert signal capable of alerting individuals who might not otherwise respond to the alarm condition, such as individuals who are asleep, children, hearing impaired, or intoxicated.

Abstract: A battery-powered supplemental alert generator is disclosed that is adapted to be mounted in close proximity to, such as within 3 or 4 feet of, a conventional smoke, heat and/or fire detector/alert device. The supplemental alert generator operates in a relatively low power mode while listening for the nearby detector/alert device to generate a standard audible alert signal. Upon detecting that a monitored sound level has reached a particular threshold, the supplemental alert generator enters into a higher power analysis mode in which it analyzes the detected signal to assess whether it is an audible alert signal. If an audible alert signal is detected, the supplemental alert generator generates one or more supplemental alert signals, such as a 520 Hz audible square wave signal. The supplemental alert generator may be used to retrofit a house, hotel, or other building to comply with new standards or to otherwise increase the effectiveness of the existing detection/alert system.

Abstract: A battery-powered supplemental alert generator is disclosed that is adapted to be mounted in close proximity to, such as within 3 or 4 feet of, a conventional smoke, heat and/or fire detector/alert device. The supplemental alert generator operates in a relatively low power mode while listening for the nearby detector/alert device to generate a standard audible alert signal. Upon detecting that a monitored sound level has reached a particular threshold, the supplemental alert generator enters into a higher power analysis mode in which it analyzes the detected signal to assess whether it is an audible alert signal. If an audible alert signal is detected, the supplemental alert generator generates one or more supplemental alert signals, such as a 520 Hz audible square wave signal. The supplemental alert generator may be used to retrofit a house, hotel, or other building to comply with new standards or to otherwise increase the effectiveness of the existing detection/alert system.

Abstract: A battery-powered supplemental alert generator is disclosed that is adapted to be mounted in close proximity to, such as within 3 or 4 feet of, a conventional smoke, heat and/or fire detector/alert device. The supplemental alert generator operates in a relatively low power mode while listening for the nearby detector/alert device to generate a standard audible alert signal. Upon detecting that a monitored sound level has reached a particular threshold, the supplemental alert generator enters into a higher power analysis mode in which it analyzes the detected signal to assess whether it is an audible alert signal. If an audible alert signal is detected, the supplemental alert generator generates one or more supplemental alert signals, such as a 520 Hz audible square wave signal. The supplemental alert generator may be used to retrofit a house, hotel, or other building to comply with new standards or to otherwise increase the effectiveness of the existing detection/alert system.

Abstract: A battery-powered supplemental alert generator is disclosed that is adapted to be mounted in close proximity to, such as within 3 or 4 feet of, a conventional smoke, heat and/or fire detector/alert device. The supplemental alert generator operates in a relatively low power mode while listening for the nearby detector/alert device to generate a standard audible alert signal. Upon detecting that a monitored sound level has reached a particular threshold, the supplemental alert generator enters into a higher power analysis mode in which it analyzes the detected signal to assess whether it is an audible alert signal. If an audible alert signal is detected, the supplemental alert generator generates one or more supplemental alert signals, such as a 520 Hz audible square wave signal. The supplemental alert generator may be used to retrofit a house, hotel, or other building to comply with new standards or to otherwise increase the effectiveness of the existing detection/alert system.

Abstract: A battery-powered supplemental alert generator is disclosed that is adapted to be mounted in close proximity to, such as within 3 or 4 feet of, a conventional smoke, heat and/or fire detector/alert device. The supplemental alert generator operates in a relatively low power mode while listening for the nearby detector/alert device to generate a standard audible alert signal. Upon detecting that a monitored sound level has reached a particular threshold, the supplemental alert generator enters into a higher power analysis mode in which it analyzes the detected signal to assess whether it is an audible alert signal. If an audible alert signal is detected, the supplemental alert generator generates one or more supplemental alert signals, such as a 520 Hz audible square wave signal. The supplemental alert generator may be used to retrofit a house, hotel, or other building to comply with new standards or to otherwise increase the effectiveness of the existing detection/alert system.

Abstract: Various inventive features are disclosed for efficiently generating regulation-compliant audible alerts, including but not limited to 520 Hz square wave alert/alarm signals, using an audio speaker. One such feature involves the use of a non-linear amplifier in combination with a voltage boost regulator to efficiently drive the audio speaker. Another feature involves speaker enclosure designs that effectively boost the output of the audio speaker, particularly at relatively low frequencies. These and other features may be used individually or combination in a given alarm-generation device or system to enable regulation-compliant audible alerts to be generated using conventional batteries, such as AA alkaline batteries. Various examples of efficiently generated regulation-compliant audible alerts and further enhancing such audible alerts by utilizing speaker enclosure designs are provided.

Abstract: Various inventive features are disclosed for efficiently generating regulation-compliant audible alerts, including but not limited to 520 Hz square wave alert/alarm signals, using an audio speaker. One such feature involves the use of a non-linear amplifier in combination with a voltage boost regulator to efficiently drive the audio speaker. Another feature involves speaker enclosure designs that effectively boost the output of the audio speaker, particularly at relatively low frequencies. These and other features may be used individually or combination in a given alarm-generation device or system to enable regulation-compliant audible alerts to be generated using conventional batteries, such as AA alkaline batteries. Various examples of efficiently generated regulation-compliant audible alerts and further enhancing such audible alerts by utilizing speaker enclosure designs are provided.