National Repository of Grey Literature 330 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
Laser-driven hard X-ray source for imaging applications
Lamač, Marcel ; Nejdl, Jaroslav (advisor)
With the advent of high-power lasers in recent decades, a unique source of hard X-ray radiation has become availible. This source of collimated, broadband, femtosecond, incoherent and hard X-ray radiation is produced when a focused laser with intensity above 10^18 W/cm^2 collides with a gas target. The strong electric field of the laser pulse ionizes the gas and interacts with the plasma generating a strong plasma wake wave. This space charge separation inside the target generates longitudal electric fields of the order of 100 GV/m. This resulting electrostatic wakefield accelerates the electrons to relativistic velocities and causes them to travel in oscillatory motion behind the laser pulse, producing hard and collimated X-ray radiation. This thesis is focused on a theoretical evaluation and an experimental design of this laser-plasma X-ray source. Furthermore, we consider the source's unique properties for novel imaging applications.
Noise reduction in LASER source device for optical trap
Gajzler, Vojtěch ; Adámek, Roman (referee) ; Brablc, Martin (advisor)
This work focuses on the reduction of noise in a laser source to increase the efficiency of an optical trap. The first part describes the issue of noise, methods of noise suppression, and the Red Pitaya control board. The following section thoroughly describes the program development using Simulink and Xilinx Vivado. Furthermore, the method of noise reduction using a PI controller is described. The conclusion of the work is focused on evaluating the experiment to verify the effectiveness of noise reduction.
Design of Therapeutic Laser for Veterinary Medicine
Hájková, Karolína ; Jelenčík, Branislav (referee) ; Rubínová, Dana (advisor)
The aim of this master thesis is design of high-power therapeutic laser for veterinary purposes. The thesis focuses on the design of laser device that will suit to a wide range of patients and also diverse environment where it is used. Emphasis is particularly placed on ergonomics which is often overlooked on existing devices of this type. An important aspect of this thesis is also appropriate choice of materials, colours and shaping to match the veterinary apparatus and the environment of use. Master thesis is based on the selection of many relevant sources, on practice observation and on consultations with users and specialists. The newly developed product will find its application in veterinary clinics and workplaces focusing on animal physiotherapy and rehabilitation.
Cross Lingual News Article Classification and Automatic Topic Discovery Using Multilingual Language Models
Dufková, Aneta ; Fajčík, Martin (referee) ; Kesiraju, Santosh (advisor)
Cílem této diplomové práce je provést mezijazykovou klasifikaci a automatickou detekci témat novinových článků s využitím předtrénovaných multijazykových modelů. Jelikož pro tento úkol nebyla k dispozici žádná vhodná datová sada, prvním přínosem této práce je vůbec takovou sadu vytvořit. Dalším krokem práce je porovnat multijazykové modely LaBSE a LASER2 v úloze klasifikace. K tomu je využita řada experiment zaměřených na trénování na omezeném počtu článků a samozřejmě testování na jazycích, které nebyly použity při tréninku. Poté je provedena automatická detekce témat, takže článek může být reprezentován nejen kategoriemi, ale také odpovídajícími slovy. Na závěr jsou výsledky popsaného procesu vizualizovány v podobě webové aplikace.
Design and production of a CNC engraving machine using an LED laser module
Novotný, Matěj ; Zemčík, Oskar (referee) ; Dvořáková, Jana (advisor)
This work focuses on the evaluation of the current state of the art and comparison of the properties of beam unconventional technologies. It discusses laser devices and the engraving process. It then focuses on the design and fabrication of a CNC engraving machine assembly using LED laser module. It describes the components used individually, their function, features, equipment to design and then the complete physical assembly of the device. Functionality was tested based on several engraving and cutting tests. Finally, the economic part of the project was discussed.
A design of engraving plotter
Brtník, Vojtěch ; Tůma, Zdeněk (referee) ; Tůma, Jiří (advisor)
This bachelor thesis, in addition to the actual design of the laser engraving laser, contains basic information about laser engraving technology and marking used in industry. It explains the physical principle of the laser and the laser source, which is essential to understand and classify laser modules. Provides an up-to-date market survey of the laser engraving modules and engraving plotters in use. In the design part, the design of an engraving plotter for SMC company is carried out using 3D models in Solidworks 2022 according to the specified parameters. The plotter design includes the selection of a suitable linear motion unit with electric drive, the assumed control, control calculations and the design of the plotter structural elements. The next section deals with the design of the support part and includes safety and functional elements. The paper concludes with a cost evaluation and recommendations for practice.
Laser surface cleaning
Macháček, Martin ; Kubíček, Jaroslav (referee) ; Sigmund, Marian (advisor)
This thesis covers feasibility of laser cleaning applied to various types of surface contaminations and treatments. In theoretical part of the theses are described basic principles of laser, a machine used in practical section (M200 by 4Jet) is introduced and corrosion and surface treatments are depicted. In practical part of the theses is described the preparation process of testing samples, the cleaning procedure and the results thereof are evaluated with emphasis on feasibility of the operation. The last section of the thesis focuses on comparison between conventional cleaning technologies and that of laser cleaning. Conclusion of the thesis summarises gained insights.
Issues of the LaserHybrid welding method
Znášik, Samuel ; Sigmund, Marian (referee) ; Kubíček, Jaroslav (advisor)
The thesis deals with the issue of using LaserHybrid welding for the energy industry where the combination of laser and arc could facilitate higher quality welds resistant to aggressive environments, corrosion and oxidation. The methods that the hybrid process produce as well as possible replacements for the MIG and MAG methods are explored, as well as the different configurations and their possible impact on the process. The possible use of the technology for hyperbaric welding is also presented. The experimental part is devoted to the welding of refractory martensitic steel used in the power industry for the production of steam turbines. Weld structures at different parameters were investigated and hardnesses were compared.
Design of Desktop Laser Engraver
Charvát, Jakub ; Křenek, Ladislav (referee) ; Rubínová, Dana (advisor)
This bachelor thesis deals with the conceptual design of a desktop laser engraving machine. The main goal is to design functional and innovative shaping that shows appropriate compactness. The thesis includes a survey of existing products and a study of the laser engraving process. The resulting solution is in accordance with functional, ergonomic and safety parameters.
Probe for Determining the Surface Condition of Small Diameter Barrels
Procházka, Adam ; Goldmann, Tomáš (referee) ; Malaník, Petr (advisor)
This thesis focuses on the analysis of methods for measuring surface profiles, as well as the design and implementation of a device for their measurement. The implemented device utilizes non-contact triangulation profilometry techniques to determine the surface profile by projecting a laser line onto the surface and capturing the projected shape at a non-zero observation angle. It alse collects information about the surface’s image texture under LED illumination. In addition to data on image texture and profile, data on the position of the captured images is also collected using a sensor measuring the device’s distance from the end of the barrel. The work also includes the design and implementation of custom control modules for the chosen LED and laser diode. The output from the device is presented in a user application. The device is designed to function in tubes with diameters from 40 millimeters.

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