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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.
491

Low-Velocity Impact Behavior of Sandwich Panels with 3D Printed Polymer Core Structures

Turner, Andrew Joseph 06 June 2017 (has links)
No description available.
492

Sulfuric Acid Corrosion to Simulate Microbial Influenced Corrosion on Stainless Steel 316L

Miller, Jacob T. January 2017 (has links)
No description available.
493

Experimental Study of Disruption of Columnar Grain Growth during Rapid Solidification

Yelamanchi, Bharat 16 September 2015 (has links)
No description available.
494

High Throughput Functional Material Deposition Using A Laser Hot Wire Process

Pangsrivinij, Suksant 13 September 2016 (has links)
No description available.
495

3D Printed Mini-Whegs Robot Design and Vibration Analysis

Passmore, Catherine M. 02 June 2017 (has links)
No description available.
496

A Study of Mixed Manufacturing Methods in Sand Casting Using 3D Sand Printing and FDM Pattern-making Based on Cost and Time

Gullapalli, Ram A. January 2016 (has links)
No description available.
497

Supernatural - Polar

Lüdicke, Katharina 17 November 2023 (has links)
Das gletscherähnliche und amorphe Modell “Supernatural - Polar“ für den Wettbewerb “Entdeckung“ ist aus meinem Konzept “SculptuReal“ 2019 entstanden. Um den Umgang mit künstlerischer Plastik für ein breiteres Publikum spannend und erfahrbar zu machen, entwarf ich eine App, mit der Skulpturen über das Interface eines Smartphones oder Tablets leicht “erspielt“ und durch das 3D-Druckverfahren ins Reelle übertragen werden können.
498

Design and evaluation of a solid-state LiDAR system : for wireless distance measurements

Hagstedt, Christian, Jönsson, Sebastian January 2022 (has links)
The advent of smarter vehicles coupled with declining costs for solid-state light detection and ranging (LiDAR) sensors unlocks the potential of cheaper devices that experience less mechanical wear while providing smaller form factors. The early state of the market makes evaluating the limited supply of available sensors interesting. This thesis investigated the possibility of creating a wireless distance measurement system, at relatively low cost, using a commercially available solid-state LiDAR sensor. A complete prototype was designed using a LeddarTech VU8 sensor. The system was fully integrated with a power supply PCB and a 3D printed enclosure. Distance data could be wirelessly transferred via Bluetooth using a Raspberry Pi 4 B. A graphical user interface (GUI) was developed to display distance data and to interact with the system in real-time. The system intends to provide a foundation for future work.
499

Geometrical accuracy of metallic objects produced with Additive or Subtractive Manufacturing: a comparative in-vitro study

Jönsson, David, Kevci, Mir January 2017 (has links)
Syftet: Utvärdera produktionstolerans av objekt som producerats genom additiv framställningsteknik (AF) för användning inom tandvård, samt att jämföra denna teknik med subtraktiv framställningsteknik (SF) genom reverse engineering.Material och metod: Tio exemplar av två olika geometriska objekt framställdes från fem olika AF maskiner och en SF maskin. Objekt A efterliknar ett inlay, medan objekt B återspeglar en modell av en fyrledsbro. Alla objekt delades in i olika mätled; X, Y och Z. Mätningarna utfördes med validerade och kalibrerade instrument. Linjära avstånd mättes med ett digitalt skjutmått och hörnradie samt vinklar mättes med ett digitalt mikroskop.Resultat: Vare sig additiv eller subtraktiv framställning uppvisade en perfekt matchning till CAD-filen med hänsyn till de parametrar som utvärderades i denna studie. Standardavvikelsen gällande linjära mätningar för subtraktiv framställning uppvisade konsekventa resultat i alla led, med undantag för X- och Y-led för objektet A och i Y-led för objekt B. Samtliga additiva tillverkningsgrupper hade en konsekvent standardavvikelse i X- och Y-led, men inte i Z-led. Med avseende på hörnradiemätningar, hade SF gruppen i överlag bättre produktionsnoggrannhet för både objekt A och B medan AM grupperna var mindre noggranna.Konklusion: Med hänsyn till begränsningarna med denna in vitro studie, stödjer resultat hypotesen, med hänsyn till att AF hade en bättre förmåga att återskapa komplexa och små geometrier jämfört med SF. Samtidigt identifierades en bättre reproducerbarhet hos SF gällande enkla geometrier och linjära avstånd. Vidare studier krävs för att bekräfta dessa resultat. / Purpose: To evaluate the production tolerance of objects produced by additive manufacturing systems (AM) for usage in dentistry and to compare with subtractive manufacturing system (SM) through reverse engineering. Materials and methods: Ten specimens of two geometrical objects were produced by five different AM machines and one SM machine. Object A mimics an inlay-shaped object, meanwhile object B reflects a four-unit bridge model. All the objects were divided into different measuring-axis; X, Y and Z. Measurements were performed with validated and calibrated equipment. Linear distances were measured with a digital calliper while corner radius and angle were measured with a digital microscope. Results: None of the additive manufacturing or subtractive manufacturing groups presented a perfect match to the CAD-file regarding all parameters included in present study. Considering linear measurements, the standard deviation for subtractive manufacturing group were consistent in all axis, except for X- and Y-axis in object A and Y-axis for object B. Meanwhile additive manufacturing groups had a consistent standard deviation in X- and Y- axis but not in Z-axis. Regarding corner radius measurements, SM group overall had the best accuracy for both object A and B comparing to AM groups. Conclusion: Within the limitations of this in vitro study, results support the hypothesis, considering AM had preferable capability to re-create complex and small geometry compare to SM. Meanwhile, SM were superior producing simple geometry and linear distances. Further studies are required to confirm these results.
500

3D-Printed Geodesic Luneburg Lens Antenna With Novel Patch Antenna Feeding

Berglund, Elin, Freimanis, Sandis January 2021 (has links)
With the roll out of new technologies and the worldbecoming more connected, there is a rising demand for higherbandwidth and new frequency bands. To meet the demand,higher frequencies are used in new communication systems.Higher frequencies come with the need for new antenna designsand one promising type of antenna is the lens antenna. In thispaper, a modulated geodesic Luneburg lens with a novel feedingmethod is proposed for use between 8-10 GHz. Furthermore, themanufacturing of the lens explores the possibility of 3D printingas a method of producing cheap antennas.The paper verifies the viability of using a patch antenna andhorn as a feeding method for a parallel-plate waveguide lens.First the lens is modeled and simulated in CST Microwave Studioand is then 3D-printed in PLA plastic and taped with coppertape. The antenna achieves -5 dB S11-parameter between 8-10GHz. The antenna also achieves 60 scanning in the azimuthplane. The antenna achieves a HPBW of 15. / Med utvecklingen av nya tekniker och envärld som blir allt mer digital är efterfrågan på större bandbreddoch nya frekvensband hög. För att möta efterfrågananvänds högre frekvenser i nya kommunikationssystem. Medanvändningen av högre frekvenser behövs nya antenndesigneroch en lovande typ av antenn är linsantennen. I den härartikeln föreslås en modulerad geodesic Luneburg lins med enny typ av matningsmetod för användning mellan 8-10 GHz. Förtillverkningen av linsen utforskas 3D-printning som en billig ochenkel metod.Artikeln verifierar användningen av en patch-antenn och etthorn som matningsmetod för en lins av parallella metallplattor.Först simuleras linsen i CST Microwave Studio och 3Dprintassedan i PLA-plast och tejpas med koppartejp. Antennenåstakommer -5 dB i S11-parameter mellan 8-10 GHz. Antennenhar en skanning av 60 i azimut-planet och har en HPBW av15. / Kandidatexjobb i elektroteknik 2021, KTH, Stockholm

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