Abstract: A received OFDM signal is demodulated by sampling the OFDM signal at successive time instants and computing a Fourier transform of the samples for a block of time instants. In addition, a sliding Fourier transform is computed at every new one of the same input samples, to extract a pilot frequency tone. From results of the sliding Fourier transform a frequency error signal is detected. This signal is fed back the in a frequency synchronization feedback loop. The frequency synchronization feedback loop may be used to track the pilot tone by adjusting a phase correction signal and/or to track sample clock frequency variations.

Abstract: In this prototype Thermoelectric Generator (TEG), a new configuration of ionized gas in a container under electric potential difference has been theoretically studied. This device is proposed to generate electric power from ambient air based on the Kinetic Theory of Gases. This prototype TGE has been designed based on the idea of making a number of ionic molecules move toward a selected direction. This prototype TEG has a similar functionality to that of photovoltaic device that is confined by the statistical limits of energy distribution over photons that have the ability to make a photoelectric effect releasing free electrons with energies greater than the voltage threshold, but in this prototype TEG, the advantage is taken from extracting power directly from the moving molecules forming gas. This design is convenient to be installed indoors to produce cold air and generate electric power.

Abstract: A received OFDM signal is demodulated by sampling the OFDM signal at successive time instants and computing a Fourier transform of the samples for a block of time instants. In addition, a sliding Fourier transform is computed at every new one of the same input samples, to extract a pilot frequency tone. From results of the sliding Fourier transform a frequency error signal is detected. This signal is fed back the in a frequency synchronization feedback loop. The frequency synchronization feedback loop may be used to track the pilot tone by adjusting a phase correction signal and/or to track sample clock frequency variations.

Abstract: A signalling tone detector for use in a communications network carrying voice traffic incorporating single frequency and dual frequency signalling tones comprises a first output path, a second output path, and a switch arranged to selectively couple an input signal to one or other of the output paths. The detector is used for the selective disablement of an echo canceller in the presence of signalling tones.

Abstract: A signalling tone detector for use in a communications network carrying voice traffic incorporating single frequency and dual frequency signalling tones comprises a first output path, a second output path, and a switch arranged to selectively couple an input signal to one or other of the output paths. The first output path comprises an automatic frequency control circuit for determining a mean frequency of an input signal, comparison means for comparing the mean frequency with stored frequency values corresponding to single tone signalling frequencies and mean values of pairs of dual tone signalling frequencies, a first discriminator for determining the presence of either a single frequency or a pair of frequencies, and a second discriminator for providing a signal output indicative of the presence of a single frequency or pair of frequencies.

Abstract: A signalling tone detector for use in a communications network carrying voice traffic incorporating single frequency and dual frequency signalling tones comprises a first output path, a second output path, and a switch arranged to selectively couple an input signal to one or other of the output paths. The first output path comprises an automatic frequency control circuit for determining a mean frequency of an input signal, comparison means for comparing the mean frequency with stored frequency values corresponding to single tone signalling frequencies and mean values of pairs of dual tone signalling frequencies, a first discriminator for determining the presence of either a single frequency or a pair of frequencies, and a second discriminator for providing a signal output indicative of the presence of a single frequency or pair of frequencies.

Abstract: A multiple energy form supply device is intended for medical use in minimally invasive and general surgery applications. The device includes a plurality of energy supply modules mounted in a movable cart. The device will also typically include a computer control means, with a central PCB that is in communication with the energy supply modules. The device will also have at least one display to aid in the operation of the device, data input mechanisms to allow various means of control of the modules, and data output devices to display and store pertinent information relative to the operation of the device.

Abstract: A sleeve assembly for use in the transition region of a catheter between a relatively stiff catheter body and a less stiff distal catheter region mediates the difference in stiffness between these two catheter regions.

Abstract: Embryonal vaccination of fowl against Newcastle disease is accomplished with ethyl methane sulfonate modified NDV-B1 virus.

Abstract: The calibration cuvette apparatus for storing and calibrating a chemical sensor in a tonometered solution includes an upper cuvette section and a lower cylindrical valve section for alternately sealing the cuvette section and admitting a gas mixture to the cuvette section. The upper cuvette section has relatively narrow diameter upper and lower ends on either side of a wide diameter middle portion. The cuvette section is adapted to receive the sensor and retain the sensor in a fluid bath in the cuvette section so that the chemical sensor portion is disposed approximately in the center of the wide middle portion of the cuvette section. The chamber formed within the cuvette section is thus shaped so as to maintain the sensor in a position in the fluid bath so that any gas bubbles within the chamber will not dry the sensor. A lower end portion of the cuvette section includes a gas communication inlet for introducing gas into said chamber to equilibrate the tonometered buffer solution.

Abstract: A calibration cuvette apparatus for storing and calibrating a chemical sensor in a tonometered solution includes an upper cuvette section and a lower cylindrical valve section for alternately sealing the cuvette section and admitting a gas mixture to the cuvette section. The upper cuvette section has relatively narrow diameter upper and lower ends on either side of a wide diameter middle portion. The cuvette section is adapted to receive the sensor and retain the sensor in a fluid bath in the cuvette section so that the chemical sensor portion is disposed approximately in the center of the wide middle portion of the cuvette section. The chamber formed within the cuvette section is thus shaped so as to maintain the sensor in a position in the fluid bath so that any gas bubbles within the chamber will not dry the sensor. A lower end portion of the cuvette section includes a gas communication inlet for introducing gas into said chamber to equilibrate the tonometered buffer solution.

Abstract: The calibration cuvette apparatus for storing and calibrating a chemical sensor in a tonometered solution includes an upper cuvette section and a lower cylindrical valve section for alternately sealing the cuvette section and admitting a gas mixture to the cuvette section. The upper cuvette section has relatively narrow diameter upper and lower ends on either side of a wide diameter middle portion. The cuvette section is adapted to receive the sensor and retain the sensor in a fluid bath in the cuvette section so that the chemical sensor portion is disposed approximately in the center of the wide middle portion of the cuvette section. The chamber formed within the cuvette section is thus shaped so as to maintain the sensor in a position in the fluid bath so that any gas bubbles within the chamber will not dry the sensor. A lower end portion of the cuvette section includes a gas communication inlet for introducing gas into said chamber to equilibrate the tonometered buffer solution.