Abstract: An acoustic Doppler system comprising a plurality of acoustic transceivers, an acoustic subsystem controller and a main processing unit operatively connected to the acoustic subsystem controller. A first of the plurality of acoustic transceivers operates at a first acoustic frequency and is operatively connected to a first group of transducers producing an acoustic signal. A second of the plurality of acoustic transceivers operates at a second acoustic frequency and is operatively connected to a second group of transducers producing an acoustic signal. The first and second acoustic transceivers are adapted to operate concurrently at the first and second acoustic frequencies. The acoustic subsystem controller is operatively connected to the first and second acoustic transceivers and controls the acoustic signals produced by the first and second group of transducers.

Abstract: An acoustic Doppler system including an acoustic subsystem controller operatively connected to a plurality of acoustic transceivers, with a first of the plurality of acoustic transceivers, operating at a first acoustic frequency, operatively connected to a first group of at least one transducer, and a second of the plurality of acoustic transceivers, operating at a second acoustic frequency, operatively connected to a second group of at least one transducer, where the acoustic subsystem controller includes a digital circuit configured to sample analog signals received from the first and second groups of transducer in pairs having a pair-wise sampling frequency that is four times the operating frequency of associated acoustic transceiver.

Abstract: An underwater sensor device comprises a submersible housing including one or more housing components, one or more sensors for monitoring and collecting water characteristics, a controller for controlling operations of the one or more sensors and an graphical user interface mounted to the housing that displays the water environmental data. The housing defines a channel that extends through one of the housing components, and at least one of the sensors is mounted to the housing and extends into the channel. The controller is disposed within the housing and is operatively connected to the one or more sensors.

Abstract: A system and method for measuring the flow of water in cross-section of a body of water is presented. The system and method comprises a housing having a first transducer and a plurality of second transducers, wherein the first transducer produces an acoustic signal for determining the depth of the body of water, and the second transducers each produce an acoustic signal for determining the velocity of a volume of water by measuring the Doppler frequency shift in the returned echo.

Abstract: An underwater sensor device comprises a submersible housing including one or more housing components, one or more sensors for monitoring and collecting water characteristics, a controller for controlling operations of the one or more sensors and an graphical user interface mounted to the housing that displays the water environmental data. The housing defines a channel that extends through one of the housing components, and at least one of the sensors is mounted to the housing and extends into the channel. The controller is disposed within the housing and is operatively connected to the one or more sensors.

Abstract: A tunable impedance inverter is presented for a Doherty amplifier circuit having first and second amplifiers connected in parallel between an input circuit for receiving an input signal and an output circuit for supplying an output signal to a load. An impedance inverter is coupled between the first amplifier and the output circuit. The inverter has an input and an output and a tunable mechanical strip line of variable electrical length interposed between the input and the output. An adjuster adjusts the electrical length of the strip line. The adjuster adjustably varies the electrical length of said pathway to thereby adjust the center frequency of said output signal.

Abstract: This invention describes a new agent for cutaneous photoprotection against UVA (I and II) and UVB radiation that contains an aqueous extract obtained from a plant in the Gramineae family from the Antarctic Continent (Deschampsia Antarctica), which presents both antioxidant and dissipation of excess UV radiation properties.

Abstract: An acoustic Doppler system comprising a plurality of acoustic transceivers, an acoustic subsystem controller and a main processing unit operatively connected to the acoustic subsystem controller. A first of the plurality of acoustic transceivers operates at a first acoustic frequency and is operatively connected to a first group of transducers producing an acoustic signal. A second of the plurality of acoustic transceivers operates at a second acoustic frequency and is operatively connected to a second group of transducers producing an acoustic signal. The first and second acoustic transceivers are adapted to operate concurrently at the first and second acoustic frequencies. The acoustic subsystem controller is operatively connected to the first and second acoustic transceivers and controls the acoustic signals produced by the first and second group of transducers.

Abstract: A system and method for measuring the flow of water in cross-section of a body of water is presented. The system and method comprises a housing having a first transducer and a plurality of second transducers, wherein the first transducer produces an acoustic signal for determining the depth of the body of water, and the second transducers each produce an acoustic signal for determining the velocity of a volume of water by measuring the Doppler frequency shift in the returned echo.

Abstract: An acoustic Doppler system including an acoustic subsystem controller operatively connected to a plurality of acoustic transceivers, with a first of the plurality of acoustic transceivers, operating at a first acoustic frequency, operatively connected to a first group of at least one transducer, and a second of the plurality of acoustic transceivers, operating at a second acoustic frequency, operatively connected to a second group of at least one transducer, where the acoustic subsystem controller includes a digital circuit configured to sample analog signals received from the first and second groups of transducer in pairs having a pair-wise sampling frequency that is four times the operating frequency of associated acoustic transceiver.

Abstract: A method for measuring channel flow discharge comprising the steps of: locating a platform carrying a fluid flow measurement device at a plurality of stations at spaced locations across a channel; determining the velocity of the platform at each station by averaging the differences between the position of the platform at a first time (t) and the position of the platform at a second time equal to the first time plus a position averaging interval (PI) for a plurality of different first times; obtaining current flow vs. depth profiles at each station by adjusting current velocity as measured by the current flow measuring device for the platform velocity; determining the flow discharge at each station.