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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
281

Korekce barev 3D scanneru a 3D tiskárny / Color Correction for 3D scanner and 3D printer

Kratochvíla, Michael January 2019 (has links)
This thesis deals with color correction of a chain that starts with the 3D Artec MHT scanner, and ends with the 3D printers (CJP – Color Jet Printing technology). In principle, it is necessary to control the color interpretation of the entire chain from the scanning of real models to the 3D print model. With color properties and their color shade, including color textures. The principle of model surface scanning using a 3D scanner is in the same principle as photo camera which scans using a conventional CMOS chip. For this reason, color palettes were scanned using the photo camera and the resulting digital data were analyzed by the Darktable software. This analysis consisted of comparing the scanned color shades of the surface with the spectrofotometer measured data. The main goal of this method was to achieve color precision in the digital data during their acquirement, adjustment and interpretation. Then the same principle was applied to the data acquired by the 3D scanner to create an ICC profile of the 3D scanner. Because the 3D printer (CJP – Color Jet Printing) uses the same principle as the 2D printer, the 2D printing device calibration principle was used again to calibrate it. There have been defined procedures that adjust the color shade to the spectrophotometrically correct shades of the resulting print on a 3D printer. Color swatches were also printed for print quality verification. It has been found that with photo camera, which was used for objective measurement in the L*a*b* coordinates of independent space, any color setting and their adjustment is very sensitive to even small imprecisions. It has been found that it is not easy to obtain accurate colors within the Detla E
282

Výroba částí prototypových forem s využitím metod rapid prototyping / Production of prototype mold parts using rapid prototyping methods

Kaloda, Vít January 2020 (has links)
The diploma thesis pointed out the possibility of using rapid prototyping methods in the field of plastic injection, specifically to make shaped inserts into the injection mold. The universal frame of the injection mold was used and only the shaped inserts were changed. The main part of the work was the construction of an injection mold with the subsequent practical production of shaped inserts for a specified part. In the introductory part, a theoretical search was performed, about which production methods in combination with suitable materials could be theoretically used. Furthermore, the polyjet and DLP methods were chosen, which were used to produce components (core and cavity). The result of the diploma thesis was a summary of all parameters, comparison of materials and production methods. Polypropylene and polyamide 6 materials were injected into the injection mold, from which the first prototype products were made. Instructions for the production of shaped inserts with the recommended technology and material were created for the selected type, which could be used in practice.
283

Parametrické 3D modely / Parametric 3D Models

Ondrejó, Michal January 2020 (has links)
The aim of this work is to propose possibilities of interconnection of objects in parametric model. Individual options are implemented in the parametric three-dimensional modeling system. This system allows the creation of models using various geometric operations, change parameters at any time, animate the created model, and save the parametric model in a human-readable format. The proposed solution was implemented and evaluated on simple example.
284

3D FDM tiskárna s výměnnou tiskovou hlavou / 3D FDM printer with a replaceable print head

Čuma, Zdeněk January 2021 (has links)
The aim of the work is to design and manufacture a mechanism for setting up and clamping the replaceable head of a 3D FDM printer. The first part of the thesis deals with 3D printing in general, the second part describes the FDM method. Part three is devoted to the selection and construction of a suitable 3D printer, the fourth part to the actual design of the head attachment. In the fifth part, a technical and economic evaluation is carried out.
285

Generation of emulsion droplets and micro-bubbles in microfluidic devices

Zhang, Jiaming 04 1900 (has links)
Droplet-based microfluidic devices have become a preferred versatile platform for various fields in physics, chemistry and biology to manipulate small amounts of liquid samples. In addition to microdroplets, microbubbles are also needed for various pro- cesses in the food, healthcare and cosmetic industries. Polydimethylsiloxane (PDMS) soft lithography, the mainstay for fabricating microfluidic devices, usually requires the usage of expensive apparatus and a complex manufacturing procedure. In ad- dition, current methods have the limited capabilities for fabrication of microfluidic devices within three dimensional (3D) structures. Novel methods for fabrication of droplet-based microfluidic devices for the generation microdroplets and microbubbles are therefore of great interest in current research. In this thesis, we have developed several simple, rapid and low-cost methods for fabrication of microfluidic devices, especially for generation of microdroplets and mi- crobubbles. We first report an inexpensive full-glass microfluidic devices with as- sembly of glass capillaries, for generating monodisperse multiple emulsions. Different types of devices have been designed and tested and the experimental results demon- strated the robust capability of preparing monodisperse single, double, triple and multi-component emulsions. Second, we propose a similar full-glass device for generation of microbubbles, but with assembly of a much smaller nozzle of a glass capillary. Highly monodisperse microbubbles with diameter range from 3.5 to 60 microns have been successfully produced, at rates up to 40 kHz. A simple scaling law based on the capillary number and liquid-to-gas flow rate ratio, successfully predicts the bubble size. Recently, the emergent 3D printing technology provides an attractive fabrication technique, due to its simplicity and low cost. A handful of studies have already demonstrated droplet production through 3D-printed microfluidic devices. However, two-dimensional (2D) flow structures are still used and the advantage of 3D-printing technique has not been fully exploited. Therefore, we apply 3D printing technology to fabricate 3D-miniaturized fluidic device for droplet generation (single emulsion) and droplet-in-droplet (double emulsion) without the need for surface wettability treat- ment of the channel walls, by utilizing 3D geometry design and fabrication. A scaling law is formulated to predict the drop size generated in the device. Furthermore, magnetically responsive microspheres are also produced with our emulsion templates, demonstrating the potential applications of this 3D emulsion generator in chemical and material engineering. Finally, we design and 3D-print a hybrid ?plug-and-play? microfluidic droplet generator, which involves a 3D-printed channel chamber and commercial tubings and fittings. By combination of 3D-printed part and market-available parts, this device can be easily assembled and disassembled, which provides a great flexibility for different demands. A scaling law has been proposed for prediction of drop size generated in the device. Furthermore, a 3D-printed concentration gradient generator and a droplet merging device based on the droplet generator have been developed to demonstrate the great scalability of 3D-printing technology.
286

Innovaciones y prótesis 3D en animales

Fecchio, Roberto 16 March 2021 (has links)
Festival de Innovación Educativa de la UPC. Ponente: Dr. Roberto Fecchio / El primer FIE de la UPC es un espacio de docentes para docentes, en donde se compartirán las estrategias innovadoras de aprendizaje que se han venido aplicando en los últimos meses de educación online. Es una oportunidad para intercambiar conocimiento, seguir aprendiendo y atrevernos a innovar como parte del proceso de enseñanza y aprendizaje.
287

Sestavení a ověření funkčnosti domácí 3D tiskárny / Assembling and Functional Verification of a Home 3D Printer

Tesař, Jaroslav January 2014 (has links)
This thesis was created as a bachelor project in the Faculty of Mechanical Engineering at VUT in Brno. In the theoretical part, the additive technology Rapid Prototyping is introduced together with the most common methods, followed by the assessment of advantages and disadvantages of the new technology and its possible uses in various fields of human activity. In the experimental part of the diploma thesis was assembled and the printing parameters were set. Consequently the comparison models were printed on the 3D home printer and on professional printer Dimension uPrint. The accuracy of the printers is compared. The thesis concludes with the analysis of technical and economical parameters.
288

Untersuchungen zum mobilen 3D-Scannen unter Tage bei K+S

Fischer, Andreas, Schäfer, Andreas January 2016 (has links)
Im Rahmen einer Diplomarbeit an der TU Bergakademie Freiberg wurden in 2014 die Grundlagen für die Auswertung von 3D-Punktwolken zur automatisierten Nachtragung des Risswerks gelegt. Um die dafür notwendigen 3D-Punktwolken möglichst wirtschaftlich zu erstellen, laufen seit 2015 Untersuchungen und Testmessungen zur Machbarkeit des untertägigen Einsatzes von mobil messenden Laserscannern. Im Folgenden werden verschiedene technische Ansätze sowie die Ergebnisse der Testmessungen und die weiteren geplanten Schritte vorgestellt. / As part of a thesis at the Technical University of Freiberg, a basis for the analysis of 3D point clouds was set for refining the mine map automatically. Since 2015 studies and test measurements have been running to create the necessary 3D point clouds as economically as possible, by using an underground mobile scanning system. Below the different technical approaches will be presented as well as the results of the test measurements and the next planned steps.
289

Kopforthesentherapie bei Patienten mit lagerungsbedingtem Plagiozephalus: Einfluss von Alter und Schweregrad der Asymmetrie bei Therapiebeginn auf die Therapiedauer und das Therapieergebnis / Head orthosis therapy in positional plagiocephaly: influence of age and severity of asymmetry on duration of therapy and treatment outcome

Kunz, Jessica January 2020 (has links) (PDF)
Zur Kopforthesentherapie in der Behandlung von Säuglingen mit lagerungsbedingten Schädelasymmetrien gibt es bisher kaum Studien, die den optimalen Behandlungsbeginn unter Berücksichtigung der Ausprägung der Asymmetrie untersuchen. Ziel der vorliegenden Studie war es daher, den Einfluss des Alters und des Schweregrades der Asymmetrie bei Therapiebeginn auf die Therapiedauer und das Therapieergebnis zu analysieren. Hierzu wurden 144 Patienten mit lagerungsbedingtem Plagiozephalus untersucht, die mittels Kopforthese behandelt wurden. Es erfolgte eine Einteilung in drei Altersgruppen (Altersgruppe I: < 24 Wochen mit N = 38 Säuglingen / Altersgruppe II: ≥ 24 bis < 32 Wochen mit N = 79 Säuglingen / Altersgruppe III: ≥ 32 Wochen mit N = 27 Säuglingen) und je zwei Schweregrade (mild-to-moderate: 30°-CVA >3mm bis <12mm / moderate-to-severe: 30°-CVA ≥12mm). Anhand stereophotogrammetrischer Datensätze wurden das Ausmaß und die Reduktion der Asymmetrie in den verschiedenen Untergruppen sowie die Therapiedauer miteinander verglichen. Es zeigte sich, dass es in allen Altersgruppen zu einer signifikanten Reduktion der Asymmetrie kam, wobei sich dieser Effekt mit steigendem Alter verringerte. Ein Therapieerfolg (= CVAI <3,5%) wurde bei Patienten mit mild-to-moderate Asymmetrie in Altersgruppe I zu 83%, in Altersgruppe II zu 69% und in Altersgruppe III zu 40% erreicht. Bei Patienten mit einer schwerwiegenderen, moderate-to-severe Asymmetrie ergab sich eine symmetrische Kopfform zu 50% in Altersgruppe I, zu 30% in Altersgruppe II und nur zu 7% in Altersgruppe III. Die durchschnittliche Therapiedauer stieg von 18,6 Wochen in Altersgruppe I, 20,0 Wochen in Altersgruppe II und 25,3 Wochen in Altersgruppe III an. Das Alter bzw. der Schweregrad der Asymmetrie bei Behandlungsbeginn wurden durch die multiple Regressionsgleichung ins Verhältnis gesetzt. Dadurch kann zukünftig die zu erwartende Verbesserung der Asymmetrie durch eine Kopforthesentherapie abgeschätzt werden. Zusammenfassend kann somit festgestellt werden, dass das Alter bei Therapiebeginn sowie der Ausprägungsgrad einer lagerungsbedingten Asymmetrie einen entscheidenden Einfluss auf Dauer und Effektivität der Kopforthesentherapie haben. Die Erfolgsrate der Therapie ist maßgeblich von diesen beiden Einflussfaktoren abhängig. Die aufgestellte Regressionsgleichung ermöglicht eine Vorhersage der Reduktion einer lagerungsbedingten Schädelasymmetrie. / Background Only few studies investigating the optimal time point to start head orthosis therapy for deformational plagiocephaly (DP) take into account the severity of skull asymmetry. The present study performs a 3D-analysis of the effects of age and severity of asymmetry on the final outcome. Methods A total of 144 patients with DP treated by molding orthosis were examined and divided into three age groups (I: <24 weeks; II: ≥24 to <32 weeks; III: ≥32 weeks) and two severity levels (mild-to-moderate: 30°-CVA ≥3mm to ≤12mm; moderate-to-severe: 30°-CVA >12mm). The extent of the reduction of asymmetry was analyzed using 3D-stereophotogrammetry. Results Therapy with molding orthosis led to a significant reduction in asymmetry in all defined age groups. Efficacy of reduction decreased with increasing age. Successful treatment (=CVAI <3.5%) of patients with mild-to-moderate asymmetry was achieved in 83%, 69% and 40% (groups I, II and III), respectively, in 50%, 30% and 7% of patients with moderate-to-severe asymmetry. The average duration of treatment increased from 18.6 to 25.3 weeks (age groups I and III). Conclusion Age at the beginning of treatment as well as severity of asymmetry have a definite impact on the duration and effectiveness of molding orthosis therapy.
290

Návrh roubeného rodinného domu v Orlických horách

Štěcha, Vojtěch January 2018 (has links)
In this thesis wood is considered as main building material. The main purpose of the thesis was to use as many natural materials as possible and combine them with modern elements to achieve the best possible individual properties. The entire building should be as ecology as possible and use natural resources as much as we can. The first theoretical part of the thesis is about general problems of using different natural materials and using them not only for the local cultural view, but also because of the spiritual view in the concept of Feng Shui. There are present a different ways of contact or radiant heating. This part also includes a brief introduction to the methodology of the software, which were used in the design of this project. The practical part is then focused on the concrete building design and its placement in the given locality in Mistrovice in Orlické hory. It also contains layout design with respect to the world's sides, an ideal combination of wood-building benefits with other natural materials, which meet today's building energy conditions at the same time. Finally, there is an overall budget and thesis including complete energy efficiency of building and the final 3D visualization of the project.

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