Ultrasound

UltrasoundUltrasound is elastic acoustic vibrations of high frequency. Our ears perceive acoustic waves in the environment with a frequency of approximately 16-20 kHz. Some unique people are able to hear much higher waves. Vibrations with higher frequency are ultrasound which is beyond our hearing. Ultrasound range is usually considered to be a frequency band from 20 000 and almost up to a billion hertz. Sound oscillations with higher frequency are called hypersound.Various devices are used for generating ultrasound vibrations. These devices can be divided into 2 groups. Mechanical energy of gas or liquid flow is the source of ultrasound in mechanical devices. Electric energy is transformed into ultrasound in electro-mechanical devices. Mechanical ultrasonic radiators can be of air and liquid type. These are, for example, whistles and sirens which have a relatively simple design and easy maintenance. They also do not require expensive high-frequency electric energy. Their efficiency coefficient is 10-20 %.Generally the phenomenon of piezoelectricity is used for emitting ultrasound frequencies. Piezoelectric quartz crystal and various piezoceramic materials are the main elements which emit ultrasound.There are various applications of the ultrasonic range. It is widely used in engineering technologies. Ultrasound methods are also becoming more and more popular in biology and medicine.Ultrasound is used in diagnostics, therapeutic and surgery treatments in various areas of clinical medicine. Ultrasound can penetrate without significant absorption into soft tissues of the body and reflect from acoustic inhomogeneities. This property allows to examine internal organs. Ultrasonic methods of diagnostics often discern tissue structure more precisely as compared with X-ray.Ultrasonic baths are used in labs and industry for cleaning lab vessels and tools. They are also used for cleaning various components from small particles. Ultrasound is used in some washing machines too.There are quite many animals in wild nature that can perceive and emit frequencies of acoustic waves much higher than 20 kHz. These are, for example, bats. They have very poor eyesight, if any, so when flying and hunting they orient themselves with the help of ultrasonic location.In biological science ultrasound is used for fighting rodents. However, many of them have got used to these ultramodern small boxes which produce squeaky sounds. Thus they are not bothered a bit by their presence any more. Ultrasound propagates well in certain materials. This allows to use it in ultrasonic flaw inspection. Ultrasound is used for intensifying galvanic processes and improving quality of surfaces which are produced by electrochemical methods.So I can endlessly enumerate unique properties of ultrasound.But to cut it short I'll just say that ultrasound is an interesting phenomenon. We may only suggest that many areas of its practical application remain yet unknown to humanity.

Category:

Science & Technology

Tags:

• frequency
• oscillation
• sound
• ultrasound
• wave

[archaeuslemachina]

cool helped me in physics exam :)