Ultrasound

U prvom dijelu diplomskog rada opisala sam povijesni razvoj ideja o zvuku, valne pojave u prirodi i pojave koje prate zvučne valove, granice čujnosti ljudskog uha te definirala ultrazvuk. U drugom dijelu opisujem rezultate eksperimenata u kojima se određuje valna duljina ultrazvuka u tekućinama i računa njegova brzina iz optički projicirane slike te kako brzina ultrazvuka ovisi o temperaturi tekućine na primjeru za destiliranu vodu. Nadalje, osim eksperimentalnog dijela koji sam odrađivala u praktikumu Odjela za fiziku, izradila sam ultrazvučni detektor šišmiša koji detektira njihovo glasanje i na taj se način može odrediti prisutnost određene vrste šišmiša na promatranoj lokaciji. U posljednjem dijelu dajem zaključak o izvedenim pokusima te povezujem dobivene rezultate s fizikalnom teorijom o ultrazvuku.In the first part of this master thesis, the development of the basic concept of the sound through the history of science as well as the wave and sound phenomena in nature were described, frequency range of a human ear was determined, and ultrasound was explained. In the experimental part the several experiments were described. Firstly, the wave length of sound in some fluids was determined and speed of sound from a projected picture was calculated. Secondly, dependence of the speed of sound on the temperature of a fluid (water) was investigated. Finally, bat detector was constructed, and detailed instructions for that were presented. Bat detector is a device which detects if bats are present at a certain location and works on frequencies of ultrasound. The application of constructed bat detector was presented at 18th International Bat Night in Osijek ZOO. In conclusion, the obtained results from the experiments were discussed and some additional application of ultrasound in our lives were described