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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.
341

3D-gedruckte Kronen in der studentischen Lehre zum Erlernen der Passungsoptimierung / 3D printed crowns in dental education for training of fitment optimization

del Hougne, Frank Michael January 2024 (has links) (PDF)
71 Studierende nahmen am Universitätsklinikum Würzburg in der Abteilung für Zahnärztliche Prothetik an einem freiwilligen Übungsseminar zum Aufpassen von Kronen mit Störstellen, die im 3D-Druckverfahren hergestellt wurden, teil. Das Übungsseminar fand an zwei Terminen statt. Zum Identifizieren der Störstellen standen Xantopren und Okklusionsspray zur Verfügung. Nach dem praktischen Teil der Übung wurde ein Fragebogen ausgefüllt. Zusätzlich wurden die aufgepassten Kronen mittels Laborscanner digitalisiert und mit einer Krone ohne Störstellen überlagert. Dadurch konnten positive und negative Oberflächenabweichungen für die Bereiche der Störstellen sowie der Gesamtinnenfläche der Kronen ermittelt werden. Die flächenbezogenen Abweichungswerte zeigten einen signifikanten Lernerfolg – gemessen anhand der Passungsparameter - zwischen den beiden Terminen des Übungsseminars. Hierbei erreichten Kronen, die mit Okklusionsspray aufgepasst wurden, signifikant geringere flächenbezogene Abweichungswerte im Vergleich zu Kronen, die mit Xantopren aufgepasst wurden. Die Auswertung der mit Schulnoten skalierten Fragen ergab signifikante Unterschiede bei der Bewertung der Härte, eines realitätsnahen Gefühls beim Einschleifen bzw. beim Aufpassen und Details wie Randschluss. Beim Vergleich der Aufpassmethoden im Fragebogen ergaben die Einfachheit beim Aufpassen, das Identifizieren der Störstellen und das präferierte Material signifikante Unterschiede. Der subjektive Lernerfolg mit den Materialien zeigte ebenfalls signifikante Unterschiede. Insbesondere die Materialeigenschaften und die Randgenauigkeit der Druckkronen wurden häufig kritisiert, die schnelle und einfache Möglichkeit zur Herstellung von Übungsmaterialien sowie deren Reproduzierbarkeit wurden von den Studierenden hingegen begrüßt. / 71 students participated at the Department of Prosthetics of the University of Würzburg in a voluntary training course for fitment optimization of 3D printed crowns with implemented areas of interference. The training course was split into two sessions. Xantopren and a powder spray were utilized to identify interferences. After completing the practical part of the training course students answered a questionnaire. The adapted crowns were digitalized with a laboratory scanner and matched with a crown without interferences. Thus, positive and negative surface deviations were identified for both the areas with interferences and the crowns’ entire inner surface. The comparison of surface deviations between both sessions of the training course revealed a significant learning outcome. Crowns adapted with powder spray had significantly lower surface deviations than crowns adapted with Xantopren. The questionnaire, scaled with school grades, revealed significant differences for evaluation of the crowns’ hardness, realism of the feeling when removing interferences und adaption of the crowns, and details such as marginal fit. When comparing both materials utilized for fitment optimization, the following aspects revealed significant differences: ease for fitment optimization, identification of interferences and preferred material. The subjective learning outcome with both materials revealed significant differences as well. Material properties and accuracy of the crowns’ edges were criticized by the students, however, students appreciated the ease, speed and reproducibility of manufacturing the crowns.
342

Multifunktionell barnvagn / Multifunctional baby carriage

Jafari, Nema January 2022 (has links)
När personer får barn, köper majoritet en barnvagn för att underlätta transporteringen samt utnyttja de diverse funktioner och användningsområde som en barnvagn kan ha. Barnvagn är ett färdmedel som samtliga familjer använder idag för att förflytta barn mellan spädbarnsåldern tills dom är cirka tre år gammal. Med detta projekt kommer förbättringar/utvecklingen av barnvagn att undersökas och, därefter kommer uppmärksamheten läggas på kravspecifikationerna, materialval, hantering, säkerhet, renlighet, miljö och hållbarhet. För att få information och åsikter från dom som använder barnvagnar, utfördes en användarstudie och efterforskning. Med hjälp av användarstudien, kunde information samlas om vad för typer av produkter som redan finns på marknaden och även inspiration för utveckling av nya produkt prototyper. Efter att användarstudier utfördes, genomfördes en idégenerering process där fokuset var att brainstormade och skissade ner tankar/ idéer på Microsoft Visio samt analyserade dem. Utefter de idéer som analyserades, beslöts det att undersöka fyra koncept mer noggrant. Dessa koncept kunde jämföras var och en samt hur lämpliga koncepterna var beroende på hur barnvagnen skulle konstrueras och dess materialval. Koncepterna illustrerades med hjälp av programmet Creo Parametric 4.0 Examensarbetet inom konstruktion - produktutveckling har genomförts under perioden januari till juni 2022 och omfattar 15 högskolepoäng, en högskoleingenjörsexamen. Examensarbetetskrivs för Högskolan i Borås. / In today's society, the majority of families with babys buy a pram/ stroller to facilitate transportation and to take advantage of the various functions and areas of use that a pram can have. Prams are a means of transport that many families use today to transport children from infancy until they are about three years old. With this project, a stroller’s improvements/development will be investigated. Attention will be paid to the requirements, specifications, material selection, handling, safety, cleanliness, environment and sustainability. In order to get information and ideas from those who use pushchairs, a user study and research had been done. With the help of the user study, information could be gathered about what types of products are already on the market and inspiration for the development of the new product prototypes. After user studies were carried out, an idea generation process was carried out wherethe focus was to brainstorm and sketch thoughts/ideas and analyze them. Following the analyzed ideas, it was decided to examine four concepts more closely. These concepts could be compared one by one and how suitable the concepts were depending on how the stroller was to be constructed and its choice of materials. The concepts were illustrated using the Creo Parametric 4.0 program. This thesis was done during the period January to June 2022 and the degree project is written for the University of Borås.
343

Mechanisms Linking CARS2 to Coronary Artery Disease

Dang, Anh-Thu 14 December 2023 (has links)
Coronary artery disease (CAD) is the leading cause of death worldwide. Genome-wide association studies (GWAS) have identified more than 200 loci associated with CAD. Here, we investigated the functional effects of a locus tagged by rs61969072 (T/G), with the common allele (T) associated with protection from CAD. Expression quantitative trait loci (eQTL) analysis demonstrated a strong association between rs61969072 and CARS2 gene expression, which increased with the T allele, in various human tissues. CARS2 encodes the mitochondrial cysteinyl-tRNA synthetase, an enzyme that attaches cysteine to its cognate tRNA. We hypothesized that CARS2 is a candidate causal gene and that CARS2 confers a protective effect against CAD. We characterized CARS2 expression in macrophages and demonstrated decreased expression in pro-inflammatory M1 macrophages. Gene expression profiling following CARS2 siRNA knockdown revealed increased levels of several pro-inflammatory cytokines. Functional enrichment analysis identified the anti-inflammatory IL-10 signaling pathway, and western blotting showed that CARS2 attenuated IL-10 pathway activation through STAT3 phosphorylation. We also demonstrated that macrophage CARS2 knockdown in a macrophage/smooth muscle cell (SMC) co-culture model elicited gene expression changes indicative of a less contractile, pro-inflammatory, SMC phenotype. We then performed an in-depth analysis of differentially expressed genes following CARS2 knockdown. Several inflammatory pathways and functions were affected, particularly Protein Kinase R (PKR), implicated in Interferon Induction and Antiviral Response. Downstream of PKR is the NF-κB signaling pathway; CARS2 knockdown led to increased NF-κB protein expression but not activation, as measured by a luciferase reporter assay. Finally, we investigated potential mitochondrial mechanisms that could lead to inflammation. Reduced CARS2 levels were found to decrease mitochondrial membrane potential. However, there was a decrease in reactive oxygen species (ROS) levels and no changes in mitochondrial DNA release, metabolism, or mitochondrial bioenergetics. While ROS are often considered harmful due to their role in oxidative damage and inflammation, studies have shown that under certain contexts, ROS can have protective effects. Further studies are required to understand the mechanisms underlying the anti-inflammatory effects of CARS2. Overall, my findings highlight a novel anti-inflammatory role of CARS2 in human macrophages, consistent with the CAD protective effect of a common GWAS-identified variant.
344

DEVELOPMENT OF AN INTERNET-BASED ANALYSIS TOOL USING THE BOUNDARY ELEMENT METHOD

Chaudhari, Sachin B. January 2000 (has links)
No description available.
345

Macintosh - Bridgeport communications CAD/CAM

Dhamija, Dinesh January 1988 (has links)
No description available.
346

An In-Vitro Comparison of Irrigation Methods Using CAD/CAM Guides and the Influence on Heat Generation at the Bone Level

Podlosky, Kelly L. 14 August 2012 (has links)
No description available.
347

What Patients Without CAD or Equivalents Should be on a Statin?

Noal, Derek, Gauer, Robert L., Wallace, Rick L. 01 January 2010 (has links)
No description available.
348

Methods to Reuse CAD Data in Tessellated Models for Efficient Visual Configurations : An Investigation for Tacton Systems AB / Metoder för att återanvända CAD-data i tesselerade modeller för effektiv visuell konfigurering : En utredning för Tacton Systems AB

KUNDA, SAKETH RAM January 2020 (has links)
Data loss has always been a side effect of sharing 3D models between different CAD systems. Continuous research and new frameworks have been implemented to minimise the data loss in CAD and in other downstream applications separately like 3D visual graphics applications (eg. 3DS Max, Blender etc.). As a first step into this research area, the thesis is an explorative study on understanding the problem of CAD data loss while exchanging models between a CAD application and a visual application. The thesis is performed at Tacton systems which provides product configurations to their customers in both CAD and visual environments and hence the research is focussed on reusing the CAD data in visual applications or restoring the data after exchange. The research questions are framed to answer the reasons of data loss and address the possible implementation techniques at the company. Being a niche topic, the thesis required inputs from different perspectives and knowledge sharing from people outside the company which proves the significance of open innovation in technology-oriented companies. Ten different ideas were brainstormed and developed into concepts to solve the problem of data loss. All the concepts are analysed and evaluated to check the functionality and feasibility of implementing it within the company workflow. The evaluations resulted in different concepts that are capable of solving the research problem. They have also been verified with various people internal and external to the company. The results also highlight the strengths and weaknesses of each of these concepts giving clear instructions to the company on the next steps. / Dataförluster har alltid varit en följd av att dela 3D-modeller mellan olika CAD-system. I forskning har nya metoder utvecklats och implementerats för att minimera dataförlusten i CAD och andra program, som t.ex. visuella 3D-grafikapplikationer (3DS Max, Blender etc.). Denna rapport är resultatet av en studie kring CAD-dataförluster när man överför modeller mellan ett CAD-program och ett visualiseringsprogram. Studien har utförts vid Tacton Systems AB, som tillhandahåller produktkonfigureringslösningar både i CAD-program och i visuella miljöer och därför har studien haft fokus på att återanvända eller återskapa CAD-data i visualiseringsprogramvaror. Forskningsfrågorna är inriktade på att hitta orsaker till dataförlusterna och möjliga lösningar för företaget. Eftersom detta är ett högspecialiserat ämne krävde arbetet insatser från olika perspektiv och kunskapsinhämtning från människor också utanför företaget, vilket visar på betydelsen av öppen innovation i teknikorienterade företag. Tio olika idéer togs fram och utvecklades till koncept för att lösa problemet med dataförluster. Alla koncept har analyserats och utvärderats för att bedöma deras funktionalitet och genomförbarhet, för att implementera dem inom företagets arbetsflöde. Utvärderingarna resulterade i sex olika koncept som skulle kunna lösa problemet. Dessa koncept har diskuterats och verifierats med olika personer inom och utanför företaget. Resultatet visar styrkor och svagheter i vart och ett av dessa koncept och ger tydliga rekommendationer till företaget om nästa steg.
349

Design and implementation of an advanced user interface for three- dimensional conceptual design on CAD/CAM systems

Tsang, Yuk-Piu January 1986 (has links)
This thesis describes research into the use of interactive methods to create three-dimensional drawings for the conceptual phase of engineering design. Discussion on developing an efficient user interface for conceptual design and techniques for creating three-dimensional sketches is provided. The work also includes design and implementation of a user interface for creating simple three-dimensional drawings. A program was written to implement the creation of three-dimensional drawings in an oblique view with a graphics tablet and multi-button cursor. It allows the user to sketch in a way similar to that done on a piece of paper. Three-dimensional data is generated from two-dimensional input. Depth cueing for the sketched object is given by interactive orthographic projections onto primary planes and rotation about different axes. The menu and display makes use of icons and color to improve user familiarity and feedback. Only straight line drawing, which is represented in arrays of end-points, is implemented. / M.S.
350

A complete geometric and topologic file structure

Auradkar, Rajendra V. 10 November 2009 (has links)
Automation of the process planning function is necessary for the effective linking of Computer-Aided Design (CAD) and Computer-Aided Manufacturing (CAM). Before automated process planning is performed, primitive geometric data from CAD databases needs to be converted to higher-level feature information required by the CAM systems. Many feature recognition algorithms have been developed to extract geometric features from different CAD representation schemes. However, the algorithms are CAD modeler dependent. This research addresses the problem of developing a standardized file format, Complete Geometric and Topological File Structure (CGTS), for feature recognition purposes. Algorithms for conversion of 3-D wire-frame data to CGTS format have been developed, using C++, and the process of feature recognition demonstrated using the CGTS file format. / Master of Science

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