Abstract: A Doppler measurement system includes a random generator outputting a control signal encoding a random selection, and an ultrasonic array transducer for emitting a sequence of transmit pulses at a target at either an adjustable steering angle (plane wave imaging) or from a selectable non-sequential transducer element order (synthetic aperture imaging) corresponding to the random selection and for receiving an echo of each transmit pulse reflected from the target. Each transmit pulse is independently adjusted to a steering angle (plane wave imaging) or selectable transducer element order (synthetic aperture imaging) corresponding to a unique random selection so that the sequence of transmit pulses is a random sweep. The system can also include a memory for storing echo data, and a processor connected to the memory for using transmit data and echo data to extract a Doppler parameter. Methods of Doppler measurement and computer-readable medium can incorporating the measurement system.

Abstract: An air treatment unit (100) arranged for an intake of a first flow (110) of air into a space (120) in communication with the air treatment unit, and arranged for a discharge of a second flow (130) of air from the space. The air treatment unit comprises a heat-exchanging unit (140) arranged for thermal exchange between the second flow of air and the first flow of air, and a catalyst (150) configured to capture at least one impurity of the first flow of air. The catalyst is provided on at least a portion (160) of the heat-exchanging unit arranged to come into contact with the first flow of air during operation of the air treatment unit.

Abstract: A Doppler measurement system includes a random generator outputting a control signal encoding a random selection, and an ultrasonic array transducer for emitting a sequence of transmit pulses at a target at either an adjustable steering angle (plane wave imaging) or from a selectable non-sequential transducer element order (synthetic aperture imaging) corresponding to the random selection and for receiving an echo of each transmit pulse reflected from the target. Each transmit pulse is independently adjusted to a steering angle (plane wave imaging) or selectable transducer element order (synthetic aperture imaging) corresponding to a unique random selection so that the sequence of transmit pulses is a random sweep. The system can also include a memory for storing echo data, and a processor connected to the memory for using transmit data and echo data to extract a Doppler parameter. Methods of Doppler measurement and computer-readable medium can incorporating the measurement system.

Abstract: A facility is provided for enhancing the reliability of a communications network so that traffic whose flow is disrupted by, for example, a faulty link, may be quickly restored to service. In particular, such traffic is restored to service by establishing a number of orders of connectivity each formed from spare link capacity, in which each succeeding order of connectivity represents the shortest loop around a preceding order of connectivity.