• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 359
  • 55
  • 43
  • 43
  • 37
  • 16
  • 16
  • 5
  • 4
  • 3
  • 2
  • 2
  • 1
  • 1
  • 1
  • Tagged with
  • 737
  • 737
  • 252
  • 248
  • 244
  • 109
  • 106
  • 85
  • 57
  • 51
  • 51
  • 48
  • 48
  • 45
  • 43
  • 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.
561

Systém pro výměnu nástrojů pro 3D tiskárnu / Tool change system for 3D printer

Karniš, Radim January 2021 (has links)
The aim of this thesis is to design and implement a toolchaning system for a 3D printer. As a consequence of such expansion, the printer gains the ability of multimaterial printing and switching between a number of active and passive tools during a single production process. In addition to extensive research of other currently available solutions, this thesis describes the complete mechanical and electrical design process of the device. It also documents the implementation of a functional sample, the creation of software both for the base system and the toolchanger expansion, and the implementation of an associated optical measurement and calibration system.
562

Mechanické vlastnosti materiálů pro 3D tisk / Mechanical properties of materials for 3D printing

Janiš, Adam January 2021 (has links)
This thesis focuses on the description of 3D printing technologies using the FDM method, which uses deposition of molten thermoplastics and their subsequent cooling and solidification layer by layer. This unique structure then shows a strong anisotropy of mechanical properties and, as a result, their testing and print settings are very important. Tensile testing of plastic materials, including indicators of mechanical properties, are described in this thesis according to ČSN EN ISO standard. The practical part presents the concept of a device capable of performing these tests. The block diagram indicates the functional elements and the connections among them. Tensile strength test is described together with results processing. Necessary product documentation is also included.
563

Simulace vlivů vyhřívané podložky na tisknutý model u 3D tiskárny / Simulation of Impact The Heated Bed on Printet Model in 3D Printer

Sodomka, Petr January 2015 (has links)
This diploma thesis solves the 3D printing problematics for non-commercial printers. Firstly possibilities of its using, heat diffusion and printing materials are described. Next part of thesis is focused on heating pads and printing nozzles for which 3D models in SolidWorks software are created. The temperature analyzes are tested with these models and then comparing of results is done. Working models for SolidWorks Plastics and SolidWorks Simulation software is created in following part. Thanks to this software tools printing model is simulated and deformation creating in printing process is observed. The most suitable solutions are chosen from gained solutions.
564

VYUŽITÍ 3D TECHNOLOGIÍ VE VEŘEJNÉM PROSTORU / THE USE OF 3D TECHNOLOGY IN THE PUBLIC SPACE

Šebánek, Jan Unknown Date (has links)
The aim of this thesis is to define the impact of rapid prototyping technology in terms of creative potential to use this technology represents a particularly sculpture and architecture. Rapid Prototyping is a generic term covering a range of technologies: 3D scan converting the already realistic three-dimensional objects in computer memory, parametric modeling, which creates three-dimensional objects based on the formative algorithms, photogrammetry method of compiling three-dimensional object from a photo, technology, 3D printing materializing after each layer objects transferred from the computer's memory. When processing the theoretical work will be explored and discussed possibilities for realization of basic three-dimensional objects using 3D technology. The second step will be to map the different methods of access to artists working with 3D technology. In the end it tried to evaluate the benefits of these technologies in the field of sculpture and architecture in terms of traditional approaches. This paper attempts to describe the possible implications and potential of this progressive field in the classical artistic disciplines such as sculpture and architecture, both in terms of benefits and in terms of the eventual negative impact with respect to increasing the availability of this technology.
565

Návrh a realizace výroby konstrukce zubní náhrady / Proposal and Implementation of Production of Dental Plate Construction

Dusbaba, Michal January 2016 (has links)
This thesis deals with a CAD programmed construction design of dental prosthetics and its subsequent production by means of a five axis machine tool. In the theoretical part of the thesis one can find characteristics and analysis of materials designed for a production of dental prosthetics constructions. Among other things, the practical part of the thesis follows up digitization of a patient´s oral cavity part with the use of Trios intraoral scanner representing the latest scanning technology. The obtained data created a basis for a design of the respective dental prosthetics construction using the shape dental system programme called DentalDesigner 2015. Furthermore, the paper deals with a production of a dental prosthetics construction by means of a five axis machine tool and pursues completion works which resulted in the prosthetics final shape. The paper is concluded with discussion comprising a summary of results acquired in the practical part beginning from dental implant introduction to insertion of the made prosthetics construction into the patient´s oral cavity.
566

prodotti da forno innovativi / INNOVATIVE BAKERY PRODUCTS / innovative bakery products

GRUPPI, ALICE 17 April 2020 (has links)
L'obiettivo principale di questo progetto è quello di trovare diverse soluzioni per migliorare le caratteristiche tecnologiche, sensoriali, di sostenibilità e nutrizionali dei prodotti da forno. Come campione sono stati scelti i biscotti perché ampiamente consumati e rappresentano una buona fonte energetica, nonostante l'elevato contenuto di zuccheri e grassi. Sono state studiate diverse strategie. 1. Produzione di una farina funzionale grazie al condizionamento enzimatico del grano per ottenere una farina intera con una migliore qualità tecnologica e un migliore profilo nutrizionale. 3. Sostituzione dell'olio di palma con un ingrediente grasso più sostenibile e più sano, come l'olio extravergine di oliva, l'olio di vinaccioli, rispetto all'olio di girasole, ampiamente utilizzato. 3. Arricchimento con diversi ingredienti funzionali: a. proteine del siero di latte: l'idrolisi enzimatica è stata studiata come strategia per ottenere ingredienti proteici adatti a produrre biscotti; b. fibre: diverse fibre, principalmente derivate da sottoprodotti, sono state testate per valutare il loro potenziale ruolo come ingredienti funzionali per migliorare la consistenza e la stabilità ossidativa dei biscotti; c. estratto di buccia d'uva di scarto: la tecnologia di stampa 3D è stata utilizzata per ridurre l'effetto termico del processo di cottura sull'attività antiossidante di un estratto incapsulato aggiunto ai biscotti. / The main objective of this Ph.D. project was to find different solutions to improve the technological, sensorial, sustainability and nutritional characteristics of bakery products. Biscuits were used because of their characteristics: they are widely consumed and they are a good energy source, despite the high content in sugars and fats. Different strategies were investigated. 1. Production of a functional flour thanks to enzymatic conditioning of the wheat to obtain a whole flour with both better technological quality and improved nutritional profile for dietetic fibre composition and antioxidant compounds. 2. Substitution of palm oil with a more sustainable and healthier fat ingredient, such as extra virgin oil, grape seeds oil, in comparison with the widely used, sunflower oil. 3. Enrichment with different functional ingredients: a. whey proteins: enzymatic hydrolysis was investigated as a strategy to get protein ingredients suitable to produce acceptable high proteins biscuits; b. fibers: different fibres, mainly derived from by-products, were tested to evaluate their potential role as functional ingredients to improve texture and oxidative stability of biscuits; c. waste grape skins extract: 3D-printing technology was used to minimize the degradation effect of the baking process on antioxidant activity of an encapsulated grape-skin extract added to biscuits.
567

Évaluation de la technologie photonique sur silicium pour le développement de liens sans fil innovants visant 40 Gb/s au-delà de 200 GHz / Evaluation of silicon photonic technology for the development of innovative 40 Gbps wireless link above 200 GHz

Lacombe, Elsa 05 November 2018 (has links)
Avec l’explosion du trafic de données mobiles, des débits supérieurs au Gb/s deviennent nécessaires pour l’utilisateur. Ainsi, le réseau de communication est en cour d’amélioration afin de promouvoir le déploiement de la 5G, notamment grâce au développement et à l’installation de systèmes sans fil d’onde millimétrique (mmW) à 10 Gb/s. Néanmoins, pour délivrer de tels débits, les liens fronthaul/backhaul sans fil connectés au cœur de réseau devront supporter des flux de données supérieurs à 40 Gb/s. Cet enjeu suscite un intérêt croissant pour les fréquences sub-mmW et THz (0.1 THz – 1 THz) autour desquelles des bandes passantes (BPs) de 100 GHz sont accessibles. Il serait en effet possible d’atteindre un débit de 100 Gb/s, tout en utilisant des formats de modulation simples et ainsi réduire la consommation d’énergie du système. Visant le marché de masse des applications haut-débits, la technologie Photonique sur Silicium est particulièrement attractive pour générer des BPs naturellement larges et pour sa capacité à forts niveaux d’intégration et faible cout de fabrication. Dans cette thèse, une technologie Photonique sur Silicium industrielle a donc été évaluée durant le développement d’un émetteur intégré THz fonctionnant sur la base d’une photodiode et pouvant délivrer 100 Gb/s. Le développement d’une antenne THz faible cout et compacte est également un aspect majeur de cette thèse afin de permettre la transmission point-à-point du signal THz. En effet, une antenne intégrée sur substrat organique faible cout et à faibles pertes et une lentille fabriquée par impression 3D ont été développées afin d’évaluer ces technologies de prototypage industriel au-delà de 200 GHz. / With the booming of mobile data traffic, the need for higher data-rates is clearly felt. To cope with this strong demand and support the 5G roll-out, the capacity of the mobile communication network is being improved every day with many solutions, among which the development and installation of millimeterwave (mmW) wireless systems operating at up to 10 Gb/s. However, in order to deliver such high speeds to the user, the fronthaul/backhaul network sending data back to the core network would require above 40 Gb/s data-rate wireless links. This challenge generates a growing interest for sub-mmW and THz frequencies (0.1 THz – 1 THz) at which up-to 100 GHz bandwidth (BW) is accessible. In such BW, it would be possible to achieve up to 100 Gb/s data-rates while using simple modulation schemes to reduce the wireless system’s power consumption. Targeting mass-market high data-rates applications, Silicon Photonics technology seems very promising as it benefits from wide intrinsic BW and powerefficient components, as well as high integration levels and low manufacturing costs. In this context, a main aspect of this PhD project is the evaluation of an industrial Silicon Photonics technology for the development of a THz system-on-chip transmitter capable of reaching up to 100 Gb/s using a photodiode. Since THz antennas are also a hot topic for THz point-to-point transmission, a second aspect of this PhD study is the design of a low-cost and compact THz antenna-system. Hence, a planar antenna using low-loss organic packaging technology and a 3D-printed plastic lens were developed in order to assess those industrial prototyping techniques above 200 GHz.
568

Évaluation des technologies d'impression 3D pour le développement d'antennes directives à large bande passante pour les liaisons backhaul en bandes millimétriques V et E / Evaluation of 3D printing technologies for the development of wide-band directive antennas for millimeter wave backhaul links in E and V frequency bands

Nachabe, Nour 06 December 2018 (has links)
Face à la demande croissante de débits de données de plus en plus élevées, l’une des principales solutions proposées par la 5G est de densifier le réseau en y intégrant notamment de nouvelles « Small cells ». La réorganisation de l’architecture du réseau mobile pour s’adapter à l’intégration poussée de ces Small cells, fait naître la problématique de la connexion backhaul entre les stations de bases desservant les Small cells et le cœur de réseau. Ainsi, des liaisons backhaul de plusieurs Gb/s de données sont nécessaires pour pouvoir assurer un débit de données d’au moins 100Mb/s à l’utilisateur qui est l’un des objectifs fixés pour la 5G. Les solutions de connexion backhaul sans fils ont un avantage indiscutable face aux coûts de déploiements de fibres optiques qui sont très élevés. Pour augmenter la capacité spectrale des liaisons sans fils, l’utilisation des fréquences millimétriques au-delà de 6 GHz caractérisées par des larges bandes passantes sera prochainement discutée pour la 5G durant le World Radiocommunication Conference 2019. Parmi ces fréquences, les bandes V (57-66GHz) et E (71-76 GHz et 81-86 GHz) ont un intérêt indéniable grâce aux larges bandes passantes disponibles ainsi qu’aux conditions de licenciement peu exigeantes. Les travaux développés dans cette thèse consistent à concevoir des antennes directives à large bande passante permettant d’établir les liens backhaul point-à-point sans fils (LoS). En exploitant les technologies de fabrications à faibles coût telles que l’impression 3D et Printed Circuit Board (PCB) sur des substrats FR4, la conception de deux types d’antenne directives a été étudiée à savoir des antennes lentilles et des antennes réseaux. / In order to address the ever-increasing demand of higher data rates, adding small cells to the existing macrocells infrastructure is one of the most important milestones of the 5G roadmap. With the integration of small cells and the re-organization of the network topology, backhaul bottleneck is the main challenge to address in the near future. Facing the costs of deployments of fiber optic connections, point-to-point wireless backhaul links using millimeter wave (mmW) frequencies are gaining prominence. 5G future frequencies, to be discussed under the World Radiocommunication Conference 2019 (WRC-19) open-up the way towards mmW frequency band where large bandwidths are naturally available. The high bandwidths available at these frequencies enable several Gbps data rate backhaul links, which is un utmost necessity to respect the 100 Mbps user-experienced data rate promised by the 5G standard. Millimeter-wave frequencies in V and E-bands unlicensed/light licensed spectrum are considered as primary candidates for backhaul links. In addition to the light license regime, the high free space path loss experienced at these frequencies is rather beneficial to limit the interference between small cells links. Moreover, the high available bandwidths at V and E-bands enable to achieve multi Gb/s links without using complex modulation schemes. In this thesis, we focused our research study on developing high gain wide-band antennas usable in point-to-point backhaul links in a Line of Sight (LoS) context. Leveraging cost-efficient technologies like 3D printing and Printed Circuit Board (PCB) on FR4 substrates, we studied two high-gain antenna types: lens antennas and flat array antennas.
569

Aufbereitung von 3D-Scandaten zur additiven Fertigung von orthopädischen Helmschalen mit Fusion 360 und Geomagic FreeForm

Matthes, Jörg, Petzold, Claudius, Mauersberger, Valentin 05 July 2019 (has links)
Im Rahmen des Forschungsprojektes ,,Entwicklung eines 3D Hochgeschwindigkeits-Rotationsdruckverfahren' an der Hochschule Mittweida, wird sich mit dem Erzeugen eines CAD-Modells eines Patientenschädels und der passgenauen Modellierung einer orthopädischen Helmschale für diesen beschäftigt. Ziel ist es die zeitintensive Modellherstellung mittels Gips einzusparen und die endgültige Helmschale im .stl-Format zu erzeugen. Weiter wird, mittels einer visuellen Programmierumgebung, ein Programm erzeugt um die Helmschale in einem polaren Koordinatensystem für den geplanten Hochgeschwindigkeits-Rotations-3D-Drucker auszurichten, zu slicen und die Koordinaten der einzelnen Punkte der Bahnkurven der Extruder auszugeben.
570

Moderní pomůcky ve výuce chemie / Modern teaching aids in chemistry education

Míka, Luděk January 2017 (has links)
No description available.

Page generated in 0.081 seconds