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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.
1

Holoscopic 3D imaging and display technology : camera/processing/display

Swash, Mohammad Rafiq January 2013 (has links)
Holoscopic 3D imaging “Integral imaging” was first proposed by Lippmann in 1908. It has become an attractive technique for creating full colour 3D scene that exists in space. It promotes a single camera aperture for recording spatial information of a real scene and it uses a regularly spaced microlens arrays to simulate the principle of Fly’s eye technique, which creates physical duplicates of light field “true 3D-imaging technique”. While stereoscopic and multiview 3D imaging systems which simulate human eye technique are widely available in the commercial market, holoscopic 3D imaging technology is still in the research phase. The aim of this research is to investigate spatial resolution of holoscopic 3D imaging and display technology, which includes holoscopic 3D camera, processing and display. Smart microlens array architecture is proposed that doubles spatial resolution of holoscopic 3D camera horizontally by trading horizontal and vertical resolutions. In particular, it overcomes unbalanced pixel aspect ratio of unidirectional holoscopic 3D images. In addition, omnidirectional holoscopic 3D computer graphics rendering techniques are proposed that simplify the rendering complexity and facilitate holoscopic 3D content generation. Holoscopic 3D image stitching algorithm is proposed that widens overall viewing angle of holoscopic 3D camera aperture and pre-processing of holoscopic 3D image filters are proposed for spatial data alignment and 3D image data processing. In addition, Dynamic hyperlinker tool is developed that offers interactive holoscopic 3D video content search-ability and browse-ability. Novel pixel mapping techniques are proposed that improves spatial resolution and visual definition in space. For instance, 4D-DSPM enhances 3D pixels per inch from 44 3D-PPIs to 176 3D-PPIs horizontally and achieves spatial resolution of 1365 × 384 3D-Pixels whereas the traditional spatial resolution is 341 × 1536 3D-Pixels. In addition distributed pixel mapping is proposed that improves quality of holoscopic 3D scene in space by creating RGB-colour channel elemental images.
2

Magnetic Micromotors in Assisted Reproductive Technology

Schwarz, Lukas 21 October 2020 (has links)
Micromotors – untethered, motile, microscopic devices – are implemented in this dissertation for two applications in the field of assisted reproductive technology. First, as synthetic motor units for individual sperm cells, representing a novel approach to counteract sperm immotility (asthenozoospermia), which is one of the most prevalent causes of male infertility. Second, as synthetic carriers of fertilized oocytes (zygotes) towards the realization of non-invasive intrafallopian transfer, representing a novel alternative to the current keyhole surgery (laparoscopy) approach to achieve early embryo transfer after in vitro fertilization. In both applications, magnetically actuated micromotors are utilized to capture, transport, and deliver individual cells in a reproducible, controllable manner. In comparison with established in vitro fertilization routines, the crucial advantage of employing micromotors for the manipulation of gametes, i.e. sperm and (fertilized) oocytes, lies in the potential transfer of decisive steps of the fertilization process back to its natural environment – the fallopian tube of the female patient – taking advantage of the untethered, non-invasive motion and manipulation capabilities of magnetic micromotors. When sperm motility can be restored with magnetic micromotors, sperm can travel to the oocyte under external actuation and control, and the oocyte does not need to be explanted for in vitro fertilization. However, if in vitro fertilization was necessary, fertilized oocytes can be transferred back to the fallopian tube by micromotors in a non-invasive manner, to undergo early embryo development in the natural environment. These novel concepts of micromotor-assisted reproduction are presented and investigated in this thesis, and their potential is analyzed on the basis of proof-of-concept experiments.:1 Introduction 6 1.1 Background and Motivation 6 1.2 Objectives and Structure of this Dissertation 9 2 Fundamentals 11 2.1 Micromotors Definition and Concept 11 2.2 Micromotors for Biomedical Applications 13 2.3 Magnetic Micropropellers 15 2.3.1 Theory 15 2.3.2 Implementation 20 2.4 Microfabrication: Direct Laser Writing 21 2.5 Assisted Reproductive Technology 23 2.5.1 In vitro Fertilization and Intracytoplasmic Sperm Injection 24 2.5.2 Embryo Transfer and Zygote Intrafallopian Transfer 25 2.5.3 The Sperm Cell and the Oocyte 26 2.6 Towards Micromotor-Assisted Reproduction 28 3 Materials and Methods 30 3.1 Fabrication of Microfluidic Channel Platforms 30 3.1.1 Tailored Parafilm Channels 30 3.1.2 Polymer Channels Cast from Micromolds 31 3.1.3 Tubular Channels to Mimic In vivo Ducts 32 3.2 Fabrication of Magnetic Micropropellers 32 3.2.1 Direct Laser Writing of Polymeric Resin 33 3.2.1.1 Design and Programming 33 3.2.1.2 Exposure and Development 35 3.2.1.3 In Situ Direct Laser Writing 35 3.2.2 Critical Point Drying 35 3.2.3 Magnetic Metal Coatings 36 3.2.4 Surface Functionalization 37 3.3 Sample Characterization 38 3.3.1 Optical Microscopy 38 3.3.2 Scanning Electron Microscopy 38 3.4 Cell Culture and Analysis 39 3.4.1 Sperm Cells 39 3.4.2 Oocytes 39 3.4.3 In vitro Fertilization 41 3.4.4 Hypoosmotic Swelling Test 44 3.4.5 Cell Viability Assays 44 3.5 Magnetic Actuation 45 3.5.1 Modified Helmholtz Coil Setup 46 3.5.2 MiniMag Setup 47 3.5.3 Experimental Procedure 48 3.5.3.1 Micromotor Performance Evaluation 48 3.5.3.2 Cell Transport Experiments 49 3.5.3.3 Cell Transfer Experiments 50 4 Micromotor-assisted Sperm Delivery 51 4.1 Micromotor Design and Fabrication 51 4.2 Actuation and Propulsion Performance 53 4.3 Capture, Transport, and Release of Sperm 56 4.4 Delivery to the Oocyte 59 4.5 Sperm Viability and the Ability to Fertilize 61 5 Micromotor-assisted Zygote Transfer 68 5.1 Micromotor Design and Fabrication 68 5.2 Actuation and Propulsion Performance 70 5.3 Capture, Transport, and Release of Zygotes 76 5.4 Transfer between Separate Environments 80 5.5 Zygote Viability and Further Development 82 6 Conclusions and Prospects 85 Appendix 87 Bibliography 93 List of Figures and Tables 108 List of Abbreviations and Terms 109 Theses 111 Selbstständigkeitserklärung 112 Acknowledgments 113 List of Publications 115 Curriculum Vitae 116
3

Technické aspekty použití 3D tisku ve výuce na ZŠ / Technical aspects of the use of 3D printing in the education at elementary school

CVRČEK, Tomáš January 2016 (has links)
This thesis in the beginning deals with the history of 3D printing and its development. For better understanding the nature of 3D printing are the significant technologies that includes. Professional part includes work with the printer MakerBot Replicator 2X. Mechanical parts of the device are analyzed together with the operating software MakerBot DesktopThe following chapter is dealing with the limits and restrictions when it is printed on said 3D printer, except that describes important aspects when working on the printer. For the creation of electronic models are suggested appropriate programs for use in elementary school. A significant milestone is forming the problems of 3D printing, which can serve as a guide for the elimination of print quality problems, malfunctioning of 3D printers and others. Interesting models are designed for teaching physics and working activities that the students facilitate understanding of the substance of the response and act as activating element within lesson. It was created a list of important sites where you can find models suitable not only for teaching in elementary schools, but also for other purposes. The last chapter deals with the economic aspect of 3D printing.
4

Vývoj technologií pro 3D tisk betonových konstrukcí / Development of technologies for 3D printing of concrete structures

Roupec, Josef January 2022 (has links)
Subject of dissertation was to itemize testing methods in fresh and hardened state of cement paste or concrete. During this process some new testing methods and specimen creation protocols were proposed. Further was created list of used materials and mix design processes which led to list of used 3D printing mixture designs and 3D printers. Next part of dissertation was devoted to creation of 3D printing mix design and observations based on them. At~the end is proposed a radical change in testing methods which utilizes latest advancements in computer science and could be part of digital design process for construction.
5

Micro structured coupling elements for 3D silicon optical interposer

Killge, Sebastian, Charania, Sujay, Lüngen, Sebastian, Neumann, Niels, Al-Husseini, Zaid, Plettemeier, Dirk, Bartha, Johann W., Nieweglowski, Krzysztof, Bock, Karlheinz 06 September 2019 (has links)
Current trends in electronic industry, such as Internet of Things (IoT) and Cloud Computing call for high interconnect bandwidth, increased number of active devices and high IO count. Hence the integration of on silicon optical waveguides becomes an alternative approach to cope with the performance demands. The application and fabrication of horizontal (planar) and vertical (Through Silicon Vias - TSVs) optical waveguides are discussed here. Coupling elements are used to connect both waveguide structures. Two micro-structuring technologies for integration of coupling elements are investigated: μ-mirror fabrication by nanoimprint (i) and dicing technique (ii). Nanoimprint technology creates highly precise horizontal waveguides with polymer (refractive index nC = 1.56 at 650 nm) as core. The waveguide ends in reflecting facets aligned to the optical TSVs. To achieve Total Internal Reflection (TIR), SiO2 (nCl = 1.46) is used as cladding. TSVs (diameter 20-40μm in 200-380μm interposer) are realized by BOSCH process1, oxidation and SU-8 filling techniques. To carry out the imprint, first a silicon structure is etched using a special plasma etching process. A polymer stamp is then created from the silicon template. Using this polymer stamp, SU-8 is imprinted aligned to vertical TSVs over Si surface.Waveguide dicing is presented as a second technology to create coupling elements on polymer waveguides. The reflecting mirror is created by 45° V-shaped dicing blade. The goal of this work is to develop coupling elements to aid 3D optical interconnect network on silicon interposer, to facilitate the realization of the emerging technologies for the upcoming years.
6

Active Lightweight – End effector (ALE) for the collaborative Robotics

Chen, Liang 09 December 2022 (has links)
This thesis provides a systematic guideline for evaluating, integrating and designing the collaborative end effector system associated with commercially available collaborative robots (cobots). On the basis of ISO/TS 15066:2016, customers’ demands are categorised as a macro demand framework and micro demand variables, which are parameterised and hierarchised. By analysing these parameters, the collaborative degree is determined to correlate the hazards with protection measures, which can demonstrate the collaborative safety level transparently. After that, the safety protection measures are specifically proposed corresponding to the potential risks. Finally, an industrial application is evaluated, a novel adapter utilised on the UR5 cobot is illustrated, and its characteristics for the collaborative operation are described.:1 Introduction 2 Robotic end effector in Assembly and Handling 3 Concept and Definition of Collaboration 4 Statement of the academic purpose and methodology 5 Guideline and Methodology for designing the Active Lightweight End-effector (ALE) for collaborative robots 6 Performance demand d4): multiplicity and versatility of end effector 7 A safety monitoring end effector (Adapter) for collaborative operations 8 A practical study of collaborative integration based on collaborative degree 9 Conclusion Appendix / Diese Arbeit liefert einen systematischen Leitfaden für die Bewertung, Integration und Gestaltung des kollaborierenden Endeffektorsystems in Verbindung mit kommerziell verfügbaren kollaborativen Robotern (Kobots). Auf der Grundlage der ISO/TS 15066:2016 werden die Anforderungen der Kunden in einen Makro-Bedarfsrahmen und Mikro-Bedarfsvariablen kategorisiert, die parametrisiert und hierarchisiert werden. Durch die Analyse dieser Parameter wird der Kollaborationsgrad ermittelt, um die Gefährdungen mit Schutzmaßnahmen zu korrelieren, die die kollaborierende Sicherheitsstufe transparent darstellen können. Danach werden die Schutzmaßnahmen entsprechend den potenziellen Risiken vorgeschlagen. Schließlich wird ein industrieller Anwendungsfall bewertet, ein neuartiger Adapter für den Einsatz an einem Roboter UR5 erläutert und dessen Kenndaten für den kollaborierenden Betrieb beschrieben.:1 Introduction 2 Robotic end effector in Assembly and Handling 3 Concept and Definition of Collaboration 4 Statement of the academic purpose and methodology 5 Guideline and Methodology for designing the Active Lightweight End-effector (ALE) for collaborative robots 6 Performance demand d4): multiplicity and versatility of end effector 7 A safety monitoring end effector (Adapter) for collaborative operations 8 A practical study of collaborative integration based on collaborative degree 9 Conclusion Appendix

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