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Diagnostics of Ti:Sa laser pulses for plasma generation
Weiss, Jiří ; Samek, Ota (referee) ; Kaiser, Jozef (advisor)
This diploma thesis is focused on investigation of temporal characteristics of laser pulses generated by oscillator with Ti:Sapphire active laser medium. In terms of properties of laserinduced plasmas the beam quality is crucial, in particular laser pulse contrast ratio. A new prototype of third order autocorrelator was designed. Pulse contrast ratio measurement is based on sum frequency generation between pulse of fundamental wavelength and its frequency doubled replica. Dynamic range of presented autocorrelator is estimated to be up to 8×10^12 which is more than currently available commercial devices can offer.
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Physical ageing of polypropylene
Weiss, Jiří ; Kučera, Jaroslav (referee) ; Tocháček, Jiří (advisor)
Physical aging of commercially produced polypropylene homopolymers Mosten was studied. The work is focused on monitoring the changes in physical properties of polymer in the time period 90 days from the date of preparation of the test specimen. The aging of polymers was realized at storage temperatures of 23 and 80 °C. The changes in crystallinity, yield strength, modulus, elongation and impact strength using DSC method, tensile tests and impact tests according to Charpy were monitored. Molecular weight distribution was determined by means of GPC at each polymer. Relationships between the changes in physical properties and polymer molecular weight were sought.
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Diagnostics of Ti:Sa laser pulses for plasma generation
Weiss, Jiří ; Samek, Ota (referee) ; Kaiser, Jozef (advisor)
This diploma thesis is focused on investigation of temporal characteristics of laser pulses generated by oscillator with Ti:Sapphire active laser medium. In terms of properties of laserinduced plasmas the beam quality is crucial, in particular laser pulse contrast ratio. A new prototype of third order autocorrelator was designed. Pulse contrast ratio measurement is based on sum frequency generation between pulse of fundamental wavelength and its frequency doubled replica. Dynamic range of presented autocorrelator is estimated to be up to 8×10^12 which is more than currently available commercial devices can offer.
|
|
|
Physical ageing of polypropylene
Weiss, Jiří ; Kučera, Jaroslav (referee) ; Tocháček, Jiří (advisor)
Physical aging of commercially produced polypropylene homopolymers Mosten was studied. The work is focused on monitoring the changes in physical properties of polymer in the time period 90 days from the date of preparation of the test specimen. The aging of polymers was realized at storage temperatures of 23 and 80 °C. The changes in crystallinity, yield strength, modulus, elongation and impact strength using DSC method, tensile tests and impact tests according to Charpy were monitored. Molecular weight distribution was determined by means of GPC at each polymer. Relationships between the changes in physical properties and polymer molecular weight were sought.
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