Abstract: A transducer for non-invasive measurement includes: at least one first piezoelectric element; a second piezoelectric element; and a base material mountable to a wall of a vessel that contains a liquid. The base material has a planar portion and an angular shaped portion. The angular shaped portion has a plurality of outer faces, a first face of the plurality of outer faces of the angular shaped portion being connected to (or part of) a first face of the planar portion, a second face of the planar portion opposite to the first face of the planar portion being mountable to the wall of the vessel, at least one second face of the plurality of outer faces of the angular shaped portion being angled to the first face of the angular shaped portion at an angle less than an angle of 90 degrees internal to the base material.

Abstract: A signal processing unit configured to: cause a first ultrasound emitter, when attached to a wall of a vessel, to emit a first ultrasound test signal; receive, from at least one ultrasound receiver, when attached to the wall of the vessel, the first ultrasound test signal; detect a time of flight of the received first ultrasound test signal; and determine that an acoustic coupling of the first ultrasound emitter and a first ultrasound receiver of the at least one ultrasound receiver to the wall of the vessel is intact if the detected time of flight corresponds to a length of a path in the wall of the vessel from the first ultrasound emitter to the at least one ultrasound receiver.

Abstract: A measurement system for measuring an inhomogeneity of a medium in a vessel includes: a first ultrasound emitter for sending a first ultrasound signal along a first path; a second ultrasound emitter for sending a second ultrasound signal along a second path different from the first path; a first ultrasound receiver for receiving the first ultrasound signal and measuring a first measurement parameter p1 of the received first ultrasound signal; a second ultrasound receiver for receiving the second ultrasound signal and measuring a second measurement parameter p2 of the received second ultrasound signal; and a control unit: receives the first measurement parameter p1 from the first ultrasound receiver, receives the second measurement parameter p2 from the second ultrasound receiver, and determines a ratio p1/p2 of the first measurement parameter p1 to the second measurement parameter p2.

Abstract: An ultrasonic Lamb wave transducer for non-invasive measurement and for emitting and/or receiving an ultrasonic Lamb wave pulse, an emission and a reception of the ultrasonic Lamb wave having an emission direction and a reception direction, respectively, the ultrasonic Lamb wave pulse being defined by at least one parameter, includes: at least one piezocomposite actuator for controlling the emission direction of the ultrasonic Lamb wave by emitting acoustic radiation at frequencies that are appropriate for generating ultrasonic Lamb waves.

Abstract: A transducer for non-invasive measurement includes: a shear-type piezoelectric element; and a host material. The shear-type piezoelectric element is mounted to a first face of the host material. A second face of the host material is mountable to a wall of a vessel that holds a liquid. When the second face of the host material is mounted to the wall of the vessel, the transducer when activated at an activation frequency launches a Lamb wave into the wall of the vessel. The transducer is designed such that a phase velocity of the Lamb wave in the wall of the vessel is greater than a speed of sound in the liquid held by the vessel.

Abstract: A ballast water treatment apparatus and a ballast water treatment system having a ballast water treatment apparatus are provided. The ballast water treatment apparatus includes a ballast water transport line configured to transport ballast water between a first location and a second location, the transported ballast water being passed through at least one injector, and a plasma generation device configured to be fed with a feed gas optionally comprising oxygen, and configured to generate a feed gas plasma by a streamer type discharge in a discharge area to provide a treated gas at a treated-gas outlet. The injector includes a liquid passage having an area constructed such as to increase a velocity of the passed-through water in a region of increased velocity, and an injector gas inlet provided in the region of increased velocity. The treated-gas outlet is in gaseous connection with the injector gas inlet.

Abstract: A Dielectric Barrier Discharge system controller for controlling a fluid treatment by a Dielectric Barrier Discharge system is provided. Therein, the strength of an effect caused by a discharge created by the Dielectric Barrier Discharge system is monitored, and the generation of high-voltage pulses by the high-voltage pulse generator is controlled. The controlling of the generation of the high-voltage pulses is adapted based on the received sensor data.

Abstract: A system for marine growth prevention including a water transport line, configured to transport water through the system, an online multi-sensor module being connected to the water transport line in an online manner and being configured to automatically analyze the water being transported through the water transport line, thereby obtaining one or more of water parameters indicative of properties of organisms in the water, a hybrid treatment module configured to treat the water by executing multiple treatment modes, and a control system configured to regulate the hybrid treatment module according to the one or more water parameters received from the online multi-sensor module.

Abstract: A ballast water treatment apparatus including a ballast water transport line configured to transport a ballast water main stream, a plasma generation device configured to generate an activated gas from a feed gas; and a mixing device. The plasma generation device includes a feed gas inlet for a feed gas, a first electrode and a second electrode, for activating the feed gas by an electric discharge between the first electrode and the second electrode thereby generating the activated gas, a cooling fluid passage for cooling the plasma generation device, the cooling fluid passage having a cooling fluid inlet and a cooling fluid outlet, the cooling fluid passage being fed with a cooling fluid, and a combining section being configured to combine the activated gas with the cooling fluid from the cooling fluid outlet to generate an activated fluid product. The mixing device is configured to mix the activated fluid product and the ballast water main stream.

Abstract: A water treatment device including a first hydrocyclone and a biocidal fluid injector is described. The first hydrocyclone has an internal space, a water inlet for supplying water into the internal space, a base outlet for discharging at least a part of the water, and an apex outlet. The biocidal fluid injector is configured to inject a biocidal fluid into the internal space for eliminating organisms present in the water. The biocidal fluid injector is positioned such that a pressure within the injected biocidal fluid is lower than a head pressure of the first hydrocyclone.

Abstract: A plasma reactor for a Dielectric Barrier Discharge (DBD) system, the system includes one or more plasma reactor modules, the one or more plasma modules are configured as transmission lines. A duration of a rise-time and/or a fall-time of a voltage pulse, fed into a first end of the one or more reactor modules is shorter than a run-time of the voltage pulse from a first end of the one or more reactor modules to a second end of the one or more reactor modules.

Abstract: A method of determining a mixing state of a medium in a container includes: transmitting a plurality of acoustic signals at least partly through the medium and receiving the plurality of acoustic signals after at least partly traversing the medium; determining at least one propagation value of at least one propagation quantity for each of the plurality of received acoustic signals to provide determined propagation values, each at least one propagation quantity being indicative of an interaction of the acoustic signals with the medium; determining at least one fluctuation value of at least one fluctuation quantity based on the determined propagation values to provide a determined at least one fluctuation value, each at least one fluctuation quantity being indicative of and/or correlating with a variance of the determined propagation values and/or with a state of a mixture; and determining the mixing state of the medium.

Abstract: A transducer for non-invasive measurement includes: at least one first piezoelectric element; a second piezoelectric element; and a base material mountable to a wall of a vessel that contains a liquid. The base material has a planar portion and an angular shaped portion. The angular shaped portion has a plurality of outer faces, a first face of the plurality of outer faces of the angular shaped portion being connected to (or part of) a first face of the planar portion, a second face of the planar portion opposite to the first face of the planar portion being mountable to the wall of the vessel, at least one second face of the plurality of outer faces of the angular shaped portion being angled to the first face of the angular shaped portion at an angle less than an angle of 90 degrees internal to the base material.

Abstract: A transducer for non-invasive measurement includes: a piezoelectric element; a base plate; and driver electronics. The piezoelectric element is mounted to a first face of the base plate. A second face of the base plate is mountable to a wall of a vessel that holds a liquid. The driver electronics drive the piezoelectric element at a plurality of activation frequencies. When the second face of the base plate is mounted to the wall of the vessel, the transducer when activated excites acoustic waves in the base plate and to launch an acoustic wave into the liquid. The transducer is designed such that an angular divergence of the acoustic wave launched into the liquid varies as a function of at least the activation frequency and a dimension of an emitter.

Abstract: A transducer for non-invasive measurement includes: a shear-type piezoelectric element; and a host material. The shear-type piezoelectric element is mounted to a first face of the host material. A second face of the host material is mountable to a wall of a vessel that holds a liquid. When the second face of the host material is mounted to the wall of the vessel, the transducer when activated at an activation frequency launches a Lamb wave into the wall of the vessel. The transducer is designed such that a phase velocity of the Lamb wave in the wall of the vessel is greater than a speed of sound in the liquid held by the vessel.

Abstract: A measurement system for determining a density ? or a compressibility ? of a liquid medium in a vessel includes: at least one pressure sensor for measuring a hydrostatic pressure ?p of the liquid medium as a measured hydrostatic pressure ?p; at least one ultrasound sensor for measuring a first time of flight t1 along a first propagation path comprising a point at a level surface of the liquid medium, and for measuring a second time of flight t2 along a second propagation path, which is different from the first propagation path; and a control unit for determining the density ? or the compressibility ? of the liquid medium based on the measured hydrostatic pressure ?p, the first time of flight t1, and the second time of flight t2.

Abstract: A signal processing unit configured to: cause a first ultrasound emitter, when attached to a wall of a vessel, to emit a first ultrasound test signal; receive, from at least one ultrasound receiver, when attached to the wall of the vessel, the first ultrasound test signal; detect a time of flight of the received first ultrasound test signal; and determine that an acoustic coupling of the first ultrasound emitter and a first ultrasound receiver of the at least one ultrasound receiver to the wall of the vessel is intact if the detected time of flight corresponds to a length of a path in the wall of the vessel from the first ultrasound emitter to the at least one ultrasound receiver.

Abstract: A measurement system for measuring an inhomogeneity of a medium in a vessel includes: a first ultrasound emitter for sending a first ultrasound signal along a first path; a second ultrasound emitter for sending a second ultrasound signal along a second path different from the first path; a first ultrasound receiver for receiving the first ultrasound signal and measuring a first measurement parameter p1 of the received first ultrasound signal; a second ultrasound receiver for receiving the second ultrasound signal and measuring a second measurement parameter p2 of the received second ultrasound signal; and a control unit: receives the first measurement parameter p1 from the first ultrasound receiver, receives the second measurement parameter p2 from the second ultrasound receiver, and determines a ratio p1/p2 of the first measurement parameter p1 to the second measurement parameter p2.

Abstract: An ultrasonic Lamb wave transducer for non-invasive measurement and for emitting and/or receiving an ultrasonic Lamb wave pulse, an emission and a reception of the ultrasonic Lamb wave having an emission direction and a reception direction, respectively, the ultrasonic Lamb wave pulse being defined by at least one parameter, includes: at least one piezocomposite actuator for controlling the emission direction of the ultrasonic Lamb wave by emitting acoustic radiation at frequencies that are appropriate for generating ultrasonic Lamb waves.

Abstract: A ballast water treatment apparatus and a ballast water treatment system having a ballast water treatment apparatus are provided. The ballast water treatment apparatus includes a ballast water transport line configured to transport ballast water between a first location and a second location, the transported ballast water being passed through at least one injector, and a plasma generation device configured to be fed with a feed gas optionally comprising oxygen, and configured to generate a feed gas plasma by a streamer type discharge in a discharge area to provide a treated gas at a treated-gas outlet. The injector includes a liquid passage having an area constructed such as to increase a velocity of the passed-through water in a region of increased velocity, and an injector gas inlet provided in the region of increased velocity. The treated-gas outlet is in gaseous connection with the injector gas inlet.