A combination of a visual warning cue and a conspicuous auditory warning cue acts synergistically to reduce bird strike frequency against a man-made structure. Methods and systems are described for providing said combination of warning cues when a bird is within a warning zone. The auditory warning cue entails at least two separate sonic pulses within one second when the bird is within the warning zone, and is defined by an intensity-weighted frequency average of between 6 kHz and 18 kHz, and an intensity at a location within the warning zone of at least 70 decibels.

A sound wave generator is configured to generate ultrasonic waves having a predetermined frequency that chases away vermin. The sound wave generator includes a power supply, a switch, an oscillation circuit, and a speaker. The power supply includes a battery that is a DC power supply and outputs DC power for generating sound waves. The switch is operated by a user of the sound wave generator to switch between supply and non-supply of power from the power supply to the oscillation circuit. When the switch is turned on, the oscillation circuit operates with DC power output from the power supply and oscillates an electrical signal having a predetermined frequency. An organic transistor is used in the oscillation circuit. The speaker converts the electrical signal oscillated by the oscillation circuit into sound waves and outputs the sound waves.

A device for generating a non-thermal atmospheric pressure plasma is disclosed. In an embodiment a device includes a first piezoelectric transformer configured to ignite a non-thermal atmospheric pressure plasma in a process medium and a control circuit configured to apply an input voltage to the first piezoelectric transformer and to perform a modulation of the input voltage such that the first piezoelectric transformer generates an acoustic signal as a result of the modulation.

A device for generating a non-thermal atmospheric pressure plasma is disclosed. In an embodiment a device includes a first piezoelectric transformer configured to ignite a non-thermal atmospheric pressure plasma in a process medium and a control circuit configured to apply an input voltage to the first piezoelectric transformer and to perform a modulation of the input voltage such that the first piezoelectric transformer generates an acoustic signal as a result of the modulation.

Provided is a mobile terminal performing a mosquito repelling function. The mobile terminal with the mosquito repelling function comprises: a frame forming a full length part to minimize the thickness of a mosquito repelling device and ensure sufficient rigidity; a battery provided on the back surface of the frame; a rear cover detachably coupled to the back surface of the frame; and a mosquito repelling device coupled to the inner surface of the rear cover.

Provided is a mobile terminal performing a mosquito repelling function. The mobile terminal with the mosquito repelling function comprises: a frame forming a full length part to minimize the thickness of a mosquito repelling device and ensure sufficient rigidity; a battery provided on the back surface of the frame; a rear cover detachably coupled to the back surface of the frame; and a mosquito repelling device coupled to the inner surface of the rear cover.

A system and method for providing effective acoustic impedance matching for a broadband ultrasonic transducer device (UTD) by adding at least one impedance matching plate (IMP) and a shim to the UTD. The IMP is a flat plate with a grid of holes and the shim is disposed between the IMP and the ultrasonic transducer, e.g. piezoelectric transducer, of the UTD.

Systems and methods are disclosed for deterring wildlife, such as bats and birds, from drawing too proximate to an operating wind turbine. Wildlife species may be sensitive to transmitted frequencies, such as ultrasonic frequencies above the range of human hearing. For example, bats may avoid areas where ultrasonic frequencies are being emitted, either because the emitted ultrasonic frequency interferes with the echolocation of the bat, or because encountering the ultrasonic frequency is uncomfortable for the bat. In some aspects, acoustic transmitters may be arranged along a length of a blade of a wind turbine. A controller may direct the acoustical transmitters to transmit signals having ultrasonic frequencies to deter wildlife encounters. The controller may direct the transmitters to transmit only during periods where wildlife encounters are likely to occur (e.g. at night, during migration seasons, during favorable weather conditions, or the like).

Systems and methods are disclosed for deterring wildlife, such as bats and birds, from drawing too proximate to an operating wind turbine. Wildlife species may be sensitive to transmitted frequencies, such as ultrasonic frequencies above the range of human hearing. For example, bats may avoid areas where ultrasonic frequencies are being emitted, either because the emitted ultrasonic frequency interferes with the echolocation of the bat, or because encountering the ultrasonic frequency is uncomfortable for the bat. In some aspects, acoustic transmitters may be arranged along a length of a blade of a wind turbine. A controller may direct the acoustical transmitters to transmit signals having ultrasonic frequencies to deter wildlife encounters. The controller may direct the transmitters to transmit only during periods where wildlife encounters are likely to occur (e.g. at night, during migration seasons, during favorable weather conditions, or the like).

A bat deterrent system to deter bats from approaching wind turbines may include a first deterrent box having a first and second transducer bank. The first transducer bank may include a first set of transducers located on a first plane and a second set of transducers located on a second plane. The second plane may be different from the first plane. The bat deterrent system may also include a second deterrent box having a third and fourth transducer bank. The third transducer bank may include a third set of transducers located on a third plane and a fourth set of transducers located on a fourth plane. The fourth plane may be different from the third plane. At least one transducer may simultaneously emit a different ultrasonic output waveform than the ultrasonic output waveform emitted from another transducer.