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Scientists placed microphones a few inches from tomato and tobacco plants, and deprived them of water and cut their stems. Plants emit ultrasonic ‘scream’ when they are hurt, researchers find ...
Sonication is the act of applying sound energy to agitate particles in a sample, for various purposes such as the extraction of multiple compounds from plants, microalgae and seaweeds. [1] Ultrasonic frequencies (> 20 kHz) are usually used, leading to the process also being known as ultrasonication or ultra-sonication .
Bird scarers is a blanket term used to describe devices designed for deterring birds by startling, confusing or otherwise repeling them, typically employed in commercial settings by farmers to dissuade birds from consuming and defecating on recently planted arable crops. Numerous bird scarers are also readily available to the public direct to ...
Plants emit audio acoustic emissions between 10–240 Hz as well as ultrasonic acoustic emissions (UAE) within 20–300 kHz. Evidence for plant mechanosensory abilities are shown when roots are subjected to unidirectional 220 Hz sound and subsequently grow in the direction of the vibration source. [6]
Electronic pest control is the name given to any of several types of electrically powered devices designed to repel or eliminate pests, usually rodents or insects. Since these devices are not regulated under the Federal Insecticide, Fungicide, and Rodenticide Act in the United States, the EPA does not require the same kind of efficacy testing that it does for chemical pesticides.
Sounds include predator cries and distress calls of a variety of birds to discourage pest birds from coming into an area. Common locations for these devices include vineyards, reclamation plants, airports, and other open areas. There are also ultrasonic avian deterrents, which are inaudible to human ears. [2] Ultrasonic bird repeller, 2008
The devices from this group are used with solid treated media. The length of the device must be such that there is mechanical resonance at the desired ultrasonic frequency of operation – one or multiple half wavelengths of ultrasound in the horn material, with sound speed dependence on the horn’s cross-section taken into account.
Yalda Night, or Shab-e Yalda (also spelled Shabe Yalda), marks the longest night of the year in Iran and in many other Central Asian and Middle Eastern countries. On the winter solstice, in a ...