|
|
Waterjet cutting of material
Veselý, Radek ; Foldyna, Josef (referee) ; Habán, Vladimír (advisor)
This bachelor thesis describes principles of utilization of high-speed liquid jet for material machining. In the first part, basic classification of liquid jets and brief description of devices for generating high pressure liquid is presented. Next, using of continuous jets is discussed. Main scope of this work is oriented at the use of so-called pulsed jets, especially at ultrasonically modulated ones. Break-up of ultrasonically modulated high-speed pulsed jet into single pulses, impact of such pulse on the surface of disintegrated material and subsequent erosion in the impact area are described. The comparison of efficiency of modulated and continual water jets is summarized in the last part of the thesis.
|
|
|
Waterjet cutting of material
Veselý, Radek ; Foldyna, Josef (referee) ; Habán, Vladimír (advisor)
This bachelor thesis describes principles of utilization of high-speed liquid jet for material machining. In the first part, basic classification of liquid jets and brief description of devices for generating high pressure liquid is presented. Next, using of continuous jets is discussed. Main scope of this work is oriented at the use of so-called pulsed jets, especially at ultrasonically modulated ones. Break-up of ultrasonically modulated high-speed pulsed jet into single pulses, impact of such pulse on the surface of disintegrated material and subsequent erosion in the impact area are described. The comparison of efficiency of modulated and continual water jets is summarized in the last part of the thesis.
|
|
|
Measurements of nonlinear optical phenomena generated by femtosecond laser pulses. Autocorrelator
PAVLÍČEK, Martin
Ultrashort intensity optical pulses are often used in science, physic or med. Therefore I will be make work, which examine these pulses. In this work I measuring width of ultrashort laser pulses. Load of this work is a make experimental measuring system, which can measure these pulses. The light is propagating as electromagnetic waves. This waves contains electric and magnetic particles. I using light characterized by electric particle. In this case, light is propagating as femtosecond laser pulse. This laser pulses are generating in modelocking lasers, they are based on phase synchronization of longitudinal modes. If pulses are propagating through anisotropic medium (nonlinear crystal), can arrive phenomenon called frequency doubling (second harmonic generating). Further in this work I explore expansion of pulse, propagating through the medium. This phenomenon called group velocity dispersion. I´m measuring the pulse width by two methods. Both of these methods are compare. Addition measure is pulse spectrum measure. From these results are calculated quality of laser source INTEGRA-i. From theoretical formulas are calculated possibility values. Theoretical and practical results are compare on end of this work.
|
guest ::
