Abstract: A transducer transmits into the bone a first plurality of excitation pulses at a plurality of frequencies and measures a plurality of echoes corresponding to the plurality of excitation pulses. An ultrasound machine calculates a plurality of energies each corresponding to a respective one of the plurality of echoes and identifies a lowest echo corresponding to a lowest of the plurality of energies. The ultrasound machine matches the lowest echo to a corresponding one of the first plurality of excitation pulses, the corresponding one of the first plurality of excitation pulses having a chosen frequency. The ultrasound machine generates an acoustic impulse response by deconvolving the corresponding one of the first plurality of excitation pulses with the lowest echo, and generates an updated sensing matrix by convolving the initial sensing matrix with the acoustic impulse response. Subsequent ultrasounds use the updated sensing matrix.

Abstract: A method and system of pulse-echo ultrasound imaging by separating transducer elements of an ultrasound transducer array separate subsets, wherein the transducer elements in one subset performs a transmit operation only, and the transducer elements in the other subset perform an echo receive operation only; and grouping the transducer elements into groups of transducer elements based on subset, where each of the groups of transducer elements has the same probability of membership in either a transmit subset or a receive subset; and randomly concatenating the groups of transducer elements into a sparse array.

Abstract: This invention relates to a heat transfer surface (3) or tubular or plate-like bodies (4) having a microstructure (7) projecting out of the base surface (3a) and consisting of projections (6) which are galvanized onto the base surface (3) with a minimum height of 10 &mgr;m. The object of this invention is to create a heat transfer surface (3) of this type which is characterized by an increase in thermal efficiency of its heat transfer surfaces (3) with the smallest possible temperature differences and is suitable for both nucleate boiling and film condensation with a justifiable manufacturing expense. The object is achieved according to this invention by the fact that the base surface (3a) is covered entirely or partially with projections (6); these projections (6) are applied in the form of ordered microstructures (7) and they have a pin shape, extending with their longitudinal axis (6c) either at a right angle to the base surface (3a) or at an angle (&agr;) between 30° and 90°.

Abstract: This invention relates to a heat transfer surface (3) or tubular or plate-like bodies (4) having a microstructure (7) projecting out of the base surface (3a) and consisting of projections (6) which are galvanized onto the base surface (3) with a minimum height of 10 &mgr;m.

Abstract: This invention relates to a pipe (1) having several internal ribs (2, 3, 4) having a spiral twist, where the ribs run with rotational symmetry with the longitudinal axis (5) of symmetry of the pipe (1). This invention creates a heat transfer pipe that will be characterized by a much better heat transfer in comparison with the previously known pipes having internal ribs, and to this end it guarantees not only an increase in the internal heat transfer surface area but also an effective cross-flow between the inside wall surface of the pipe and the core flow near the longitudinal axis of symmetry. To that end, the free ends (2c, 3c, 4c) of the internal ribs (2, 3, 4) are a distance (a) from the longitudinal axis (5) of symmetry of the pipe (1), which is in the range of 1:12 to 1:3 in relation to the inside diameter (d) of the pipe; and all the internal ribs (2, 3, 4) run in the same direction (arrow 6) and with the same spiral length (L) with a spiral twist to the longitudinal axis (5) of symmetry.

Abstract: This invention relates to a pipe (1) having several internal ribs (2, 3, 4) having a spiral twist, where the ribs run with rotational symmetry with the longitudinal axis (5) of symmetry of the pipe (1). This invention creates a heat transfer pipe that will be characterized by a much better heat transfer in comparison with the previously known pipes having internal ribs, and to this end it guarantees not only an increase in the internal heat transfer surface area but also an effective cross-flow between the inside wall surface of the pipe and the core flow near the longitudinal axis of symmetry. To that end, the free ends (2c, 3c, 4c) of the internal ribs (2, 3, 4) are a distance (a) from the longitudinal axis (5) of symmetry of the pipe (1), which is in the range of 1:12 to 1:3 in relation to the inside diameter (d) of the pipe; and all the internal ribs (2, 3, 4) run in the same direction (arrow 6) and with the same spiral length (L) with a spiral twist to the longitudinal axis (5) of symmetry.