To see the other types of publications on this topic, follow the link: 3DPD.
Dissertations / Theses on the topic '3DPD'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 47 dissertations / theses for your research on the topic '3DPD.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Rodríguez, Morante David. "Papel de la angiografía ecográfica con Power Doppler tridimensional (sistema vocal) en el manejo de masas anexiales sospechosas de malignidad." Doctoral thesis, Universitat de Barcelona, 2009. http://hdl.handle.net/10803/2489.
Full textAbstract:
OBJETIVO. El objetivo de este estudio fue explorar la capacidad de la ecografía tridimensional con Power Doppler (3DPD) para discriminar los tumores benignos y malignos dentro del grupo de masas anexiales sólido-quísticas con vascularización central y definir los puntos de corte de los índices 3DPD que se deben utilizar en un entorno clínico. MÉTODOS. Un total de 143 mujeres consecutivas (edad media, 50,4 años, rango, 17-82 años) con diagnóstico de lesión sólido-quística o sólida en modo B y con vascularización central en el 2DPD fueron evaluadas con ecografía 3D PD antes de la cirugía. El 3DPD se utilizó para evaluar la vascularización en las proyecciones papilares y áreas sólidas. Los índices vasculares (índice de vascularización [VI], índice de flujo [FI], y el índice vascularization-flujo [VFI]) se calculan automáticamente. El diagnóstico histológico definitivo se obtuvo en cada caso.
RESULTADOS. Un total de 113 masas (74%) eran malignas y 39 (26%) fueron benignoa. La evaluación morfológica reveló 30 uniloculares sólidas (19,7%), 43 multilocular sólidas (28,3%), y 79 masas sólidas (52%). La media VI (9,365% frente al 3,3%, P <.001), FI (34,318 versus 28,794; p <.001), y VFI (3,233 frente a 1,15; P <0,01) fueron significativamente mayores en los tumores malignos. No se encontraron diferencias en el índice de resistencia, índice de pulsatilidad, y la velocidad pico sistólica. El análisis de la curva ROC reveló un área bajo la curva de 0,77 (intervalo de confianza del 95%, 0.69-0.85), 0,71 (0.60-0.81) y 0.75 (0.66-0.83) para la VI, FI y VFI, respectivamente. Para reducir la tasa de falsos positivos en casi una tercera parte, los valores de sensibilidad para el VI (corte, 1,556%), FI (25,212), y VFI (0,323) fueron 92%, 95% y 93%, respectivamente.
CONCLUSIONES. Los índices vasculares con 3DPD son útiles para reducir la tasa de falsos positivos en lesiones sólidas y sólido-quísticas con vascularización central.
PALABRAS CLAVE: masa anexial; cáncer de ovario; Power Doppler, 3DPD
OBJECTIVE. The purpose of this study was to explore the role of 3-dimensional (3D) power Doppler (PD) sonography to discriminate between benign and malignant cystic-solid and solid vascularized adnexal masses and to define cutoff values for 3D PD indices to be used in a clinical setting.
METHODS. A total of 143 consecutive women (mean age, 50.4 years; range, 17-82 years) with diagnoses of cystic-solid or solid vascularized adnexal masses on B-mode and 2-dimensional PD sonography were evaluated by 3D PD sonography before surgery. Three-dimensional PD sonography was used to assess vascularization within papillary projections and solid areas with a virtual organ computer-aided analysis program.
Three-dimensional PD vascular indices (vascularization index [VI], flow index [FI], and vascularizationflow index [VFI]) were automatically calculated. A definitive histologic diagnosis was obtained in each case.
RESULTS. A total of 113 masses (74%) were malignant, and 39 (26%) were benign. Morphologic evaluation revealed 30 unilocular solid masses (19.7%), 43 multilocular solid masses (28.3%), and 79 mostly solid masses (52%). The mean VI (9.365% versus 3.3%; P < .001), FI (34.318 versus 28.794; P < .001), and VFI (3.233 versus 1.15; P < 0.01) were significantly higher in malignant tumors. No differences were found in the resistive index, pulsatility index, and peak systolic velocity. Receiver operating characteristic analysis revealed an area under the curve of 0.77 (95% confidence interval, 0.69-0.85), 0.71 (0.60-0.81), and 0.75 (0.66-0.83) for the VI, FI and VFI, respectively. For reducing the false-positive rate by almost one-third, sensitivity values for the VI (cutoff, 1.556%), FI (25.212), and VFI (0.323) were 92%, 95%, and 93%, respectively. CONCLUSIONS. Three-dimensional PD vascular indices could be helpful for reducing the false-positive rate in cystic-solid and solid vascularized adnexal masses.
KEY WORDS: adnexal mass; ovarian cancer; 3-dimensional power Doppler sonography.
2
Lange, Katharina. "Multidimensionale Darstellung der proximalen RCA in 3D4D- Technik im Vergleich zur Koronarangiographie." Doctoral thesis, Universitätsbibliothek Leipzig, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-146506.
Full textAbstract:
Das Ziel der vorliegenden Studie war die Analyse der Detektierbarkeit von Stenosen und Lumenverschlüssen im proximalen Bereich der rechten Koronararterie mit konventioneller 2D- und 3D- Echokardiographie von transthorakal. Zusätzlich wurden die Befunde der 3D-Echoloops mit den Untersuchungsergebnissen der Koronarangiographie verglichen. Methodisch wurden daher bei Patienten mit bestehender Indikation zur Koronarangiographie vorhergehende zweidimensionale parasternale Lang- (n=91) und Kurzachsenaufnahmen (n=76), sowie parasternale dreidimensionale (n=91) echokardiographische Aufnahmen des Ostiums und der proximalen Region der rechten Herzkranzarterie durchgeführt. Durch zusätzliche Schnittebenen der proximalen Abschnitte der rechten Koronararterie sollte die konventionelle zweidimensionale Echokardiographie für eine Stenosendetektion ergänzt werden. Diese ermöglichten eine genaue Darstellung der rechtskoronaren Morphologie im proximalen Gefäßbereich. Maximal konnten die proximalen 35mm der rechten Koronararterie untersucht werden. Die Ergebnisse der einzelnen verschiedenen echokardiographischen Dokumentationen wurden miteinander und mit denen der Koronarangiographie verglichen. Insgesamt zeigten sich keine signifikanten Unterschiede zwischen den Ergebnissen der 2D Echokardiographie und der Koronarangiographie. Die Diameter der Streckenmessungen an der rechten Koronararterie in der 3D-Echokardiographie und der Koronarangiographie sind hingegen in ihren Mittelwerten signifikant verschieden. Dies ist durch häufigere Sekantenanschnitte der Gefäße mittels Echokardiographie bedingt. Die höchste Sensitivität konnte mittels 3D-Echokardiographie (98%) nachgewiesen werden, wohingegen die zweidimensionale Technik bessere Spezifitäten (91% in 2D-Langachsen- und 92% in 2D-Kurzachsen-Aufnahmen) aufweist. Diese Ergebnisse zeigen den Nutzen der Echokardiographie im klinischen Alltag zur intravasalen Stenosendetektion der rechten Koronararterie.
3
Gatto, Matteo. "Investigation of 3DP technology for fabrication of surgical simulation phantoms." Thesis, Loughborough University, 2011. https://dspace.lboro.ac.uk/2134/8362.
Full textAbstract:
The demand for affordable and realistic phantoms for training, in particular for functional endoscopic sinus surgery (FESS), has continuously increased in recent years. Conventional training methods, such as current physical models, virtual simulators and cadavers may have restrictions, including fidelity, accessibility, cost and ethics. In this investigation, the potential of three-dimensional printing for the manufacture of biologically representative simulation materials for surgery training phantoms has been investigated. A characterisation of sinus anatomical elements was performed through CT and micro-CT scanning of a cadaveric sinus portion. In particular, the relevant constituent tissues of each sinus region have been determined. Secondly, feedback force values experienced during surgical cutting have been quantified with an actual surgical instrument, specifically modified for this purpose. Force values from multiple post-mortem subjects and different areas of the paranasal sinuses have been gathered and used as a benchmark for the optimisation of 3D-printing materials. The research has explored the wide range of properties achievable in 3DP through post-processing methods and variation of printing parameters. For this latter element, a machine-vision system has been developed to monitor the 3DP in real time. The combination of different infiltrants allowed the reproduction of force values comparable to those registered from cadaveric human tissue. The internal characteristics of 3D printed samples were shown to influence their fracture behaviour under resection. Realistic appearance under endoscopic conditions has also been confirmed. The utilisation of some of the research has also been demonstrated in another medical (non-surgical) training application. This investigation highlights a number of capabilities, and also limitations, of 3DP for the manufacturing of representative materials for application in surgical training phantoms.
4
Wang, Hong-Ren 1973. "Gradient-Index (GRIN) lenses by Slurry-based Three-Dimensional Printing (S-3DP)." Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/30248.
Full textAbstract:
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2005.In title on t.p., superscript "TM" follows "S-3DP".
Includes bibliographical references.
GRIN lenses with vertical index variation and radial index variation have been successfully fabricated using S-3DPTM. Two silica-based material systems, A1203-SiO₂ and BaO-SiO₂, have been studied and used for the fabrication of GRIN lenses. Aluminum nitrate was dissolved in water to provide the dopant salt solution for S-3DPTM. The pre-sintering treatment at 1000 ⁰Cfor 24 hours in. vacuum (-5x10-6 torr) was used to remove the hydroxyl groups that cause bubbles during sintering. The sintering condition for the A1203-SiO₂ material system was found to be 1650 ⁰C for 30 minutes in vacuum. Two alumina-doped silica GRIN lenses with vertical index variation, Design 1.63 [percent] max and Design 2.5 [percent] max, were fabricated with effective focal lengths of 10.00 cm and 6.10 cm, respectively. An alumina-doped silica GRIN lens with radial parabolic index variation also was fabricated with effective focal lengths of 63.75 cm in the x direction and 52.50 cm in the y direction. The BaO-SiO₂ material system, which has a 2.4 stronger index changing ability than the A1203-SiO₂ material system, also was developed. Barium acetate was used as the dopant source. The pre-sintering treatment was found to be 900 ⁰C for 18 hours in air to convert barium acetate to barium oxide. The sintering condition was found to be 1725 ⁰C for 10 minutes in vacuum. A barium oxide-doped GRIN lens with radial parabolic index variation was fabricated. Its effective focal length was measured to be 14.63 cm in the x direction and 11.14 cm in the y direction. The barium oxide concentration profiles were measured. The theoretical focal lengths were calculated and compared with the effective focal lengths.
by Hong-Ren Wang.
Ph.D.
5
Oliveira, Mark A. (Mark Anthony) 1977. "Slurry based Three Dimensional Printing (S-3DP tm) of tungsten carbide cobalt." Thesis, Massachusetts Institute of Technology, 2002. http://hdl.handle.net/1721.1/109638.
Full text
6
Kang, Jinah. "Retrospective Three-dimensional facial soft tissue analysis in skeletal Class I malocclusions with premolar extractions." Master's thesis, Temple University Libraries, 2018. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/512008.
Full textAbstract:
Oral BiologyM.S.
Objectives: Decreased volume and atrophy are hallmarks of aging facial soft tissues. In perioral region, a hallmark is deepening of nasolabial folds. It is unknown how extraction orthodontic treatment affects such tissues. This study describes nasolabial fold regional changes in premolar extraction cases. Methods: Pre- and post-treatment 3dMD images of 14 skeletal Class-I patients with 4 premolar extractions were studied for changes of tissue thickness in the nasolabial fold region. All subjects were treated at Temple University. The sample consisted of 10 females and 4 males aged 12 -26 years old and included three ethnicities: Asian, Hispanic, and African American. With the aid of 3dMD Vultus software, both qualitative and quantitative analyses were collected. Color histograms were created for qualitative analyses, and quantitative volumetric changes in cheek volume were correlated to 2-D cephalometric lip thickness, lip retraction, and incisor retraction. Data were analyzed by Spearman’s rho for lip thickness, lip retraction, and incisor retraction. Regression analyses were completed controlling for age, gender, and ethnicity. Results: In this sample of Class-I malocclusion patients with 4 premolar extraction treatment, quantitative results showed no significant correlations were found between 2-D soft tissue thickness and volumetric changes around the nasolabial fold region. Moreover, none of the other characteristics including, change in the upper lip in 2-D cephalometric measurements, age, and gender were factors that correlated with volumetric changes around the nasolabial fold. The qualitative findings showed changes in lips and commissures did not affect the soft tissues around the nasolabial fold areas. Overall, there were no significant correlations between the thickness of soft tissue, change in the lips in 2-D, age, ethnicity, and gender in volumetric changes. Conclusions: Data generated by this investigation did not imply any cause-and-effect relationship between measurements of lip thickness, lip retraction, and incisor retraction to the deepening of the nasolabial fold.
Temple University--Theses
7
Reeve, Glen M. D. "Sedimentation And Hydrodynamics of Whitianga Estuary." The University of Waikato, 2008. http://hdl.handle.net/10289/2344.
Full textAbstract:
Whitianga Estuary is a bayhead barrier type estuary located on the east of the Coromandel Peninsula, North Island, New Zealand. The catchment has undergone many land-use changes since pre-European settlement. In some areas of the catchment land-use has changed from native forest to grasslands to forestry and back to pasture. These changes in catchment land-use all contribute to increased sedimentation into the estuary. Development of the estuary itself has also occurred in recent times. Much growth has been focussed around the estuary due to Whitianga town-ship having a large boating community, and includes a 170 berth marina and wharf situated at the tidal inlet entrance to the estuary. These, and the extensive canal development engineering works can have substantial impacts on the sedimentation regime, and may modify tidal circulation, flushing, and sediment deposition within the estuary. The principle aim of this research is to assess hydrodynamics and sedimentation of the estuary for future management and development purposes, and also to model different scenarios in order to determine the most cost effective, and least obtrusive design for a proposed boat-ramp and approach channel near the marina. To determine sedimentation rates, sediment cores from four locations were collected to depths of 1 m. Coring locations were chosen based on preliminary model run results, selecting areas that appeared to be long-term sediment sinks of a stable nature. Cores were divided into 10 mm sections and prepared for 210Pb dating and heavy metal analysis, to make an assessment of the vertical sedimentation rates. Recent sedimentation rates were found to be as high as 9 mm/yr post-1950s and past sedimentation rates as high as 30 mm/yr pre-1950s. The use of heavy metal analysis for dating proved difficult as the background levels of the conservative elements used to normalise results varied, making the geochemical analysis approach inappropriate. As bathymetry is one of the most important aspects of modelling, a large amount of surveying was undertaken for this study. LiDAR, singlebeam data, and recent rectified aerial photographs were interpreted for the creation of a bathymetric grid file to be used for hydrodynamic modelling of the estuary. The 3DD numerical model was used to determine tidal flows and current velocities. From this initial hydrodynamic model a particle-tracking model was created to determine sediment transport pathways within the estuary. From the initial 20 m model it was then possible to create a number of nested model grids for the purpose of determining the best practice scenario for the creation of a proposed boat ramp and associated approach channel near the harbour entrance. Hydrodynamic results suggest that residual circulation in Whitianga Estuary is nearly in balance, with a low ebb tidal domination present. Particle tracking results suggest that sediment entrained and carried into and within the estuary will accumulate on the intertidal flats. Sediment transport modelling indicates that the impact of a proposed boat-ramp will result in sedimentation of the dredged approach channel due to reductions in residual and tidal velocities.
8
Brown, Paul. "Magneto-responsive surfactants." Thesis, University of Bristol, 2012. http://hdl.handle.net/1983/41cd19c9-3d4d-47c9-a6a6-dfcab12586f2.
Full textAbstract:
Surfactants comprise one of the largest volume commodity chemicals in the world and have multifarious uses from pharmaceuticals, agrochemicals, food, fuel and lubricant additives, paints and inks as well as detergents and cleaning agents. The ability to control surfactants once they are in solution is of great importance not only for scientific reasons but also because of environmental and economic interest. To this end, surfactants sensitive to changes in pH, temperature, C02, light and redox have already been developed. This thesis investigates a new class of surfactants designed to be magnetically active, whereby the composition and physico-chemical properties of a system may be perturbed simply by the switching "on" and "off" of a magnetic switch and with no significant energy input. The thesis demonstrates that these new magneto-responsive surfactants behave like conventional surfactants but are now bifunctional allowing for new magnetic approaches where previously magnetic nanoparticles have been employed. For example, the magnetic properties makes it easier to round up and remove the surfactant from a system once it has been added. By developing the first nanoparticle-free magnetic emulsions the potential for further applications in environmental clean ups (e.g. oil spills), water treatment or drug delivery have been demonstrated. In addition to this, the combination of surfactant adsorption and intrinsic magnetism has allowed for the control and manipulation of biomolecules without the need for magnetic nanoparticles. This work explores both the fundamental properties of these novel surfactants and also takes significant steps to optimize the surfactants for potential applications.
9
Håkansson, Filip. "3D PDF." Thesis, Jönköping University, JTH, Civil Engineering, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-1341.
Full textAbstract:
This report is about Adobe Acrobat 3D and their new PDF format witch can contain 3 dimensional models that are interactive. The purpose is to find out if the program and the format work in a level that is suitable for the market. To create this PDF you need Acrobat 3D installed on your computer but it only needs Acrobat Reader 7 or 8 to open it, and the Reader is free to download on the internet.
The examination is focusing on four formats: U3D, 3DS, DWG and DXF because they are the most common in the building industry seen from the architects’ way. From a 3D model exported to these four formats they where converted to PDF in different settings to be compared in different points as information and size of the files. The result where put together in tables for an easy overview.
During the work there were no big differences between the results from the different settings noticed. The differences depended more from which format the PDF where converted from. Then the program is not that old on the market there are still some things that can be improved.
10
Schuler, Megan G. "Perception of profile appearance as judged by peers using 3D video imaging." VCU Scholars Compass, 2016. http://scholarscompass.vcu.edu/etd/4157.
Full textAbstract:
The purpose of this study was to investigate the social perceptions of subjects with differing lip position and facial convexity in three dimensions. A 3dMD camera (3dMD, Atlanta, GA) was used to capture 3D images of 9 subjects’ faces. The images were altered to have ideal lip position and ideal convexity, ideal lip position and Class II convexity, Class II lip position and ideal convexity, and Class II lip position and Class II convexity. 400 laypersons rated their perceptions of the subjects’ athletic ability, popularity, leadership, and intelligence on a VAS scale. Subjects with ideal lip position relative to the E-line were rated significantly higher for leadership and intelligence. Males with ideal facial convexity were judged to be better leaders and more intelligent than those with Class II convexity. Subjects with ideal lip position were given the highest mean VAS scores for all four social attributes. The perception of differences related to facial convexity was inconsistent.
11
Carty, Orla. "Study on facial asymmetry in children under 16 years from the North West of England using three-dimensional images (3dMD)." Thesis, University of Liverpool, 2018. http://livrepository.liverpool.ac.uk/3027770/.
Full textAbstract:
Objectives: The primary objective was to determine the extent of facial asymmetry in a standard population of children from the North West of England using a landmark based approach on 3-dimensional (3d) images. The secondary objectives were to investigate the direction and severity of nose and chin deviation and the correlation between them, to determine the relationship between gender and facial asymmetry and to investigate if asymmetry differs with age. Design/Setting: A retrospective cross-sectional cohort study undertaken at Alder Hey Children's Hospital. Subjects: Participants were children of either gender and under 16 years of age (mean 7.36 years) with all types of skeletal relationships who volunteered to have 3d images (using 3dMD software) of their head and face captured for research purposes. Methods: Images of 145 children were available. Following the application of exclusion criteria and a panel assessment including 2 Orthodontic Registrars, 2 Orthodontic Consultants and a Medical Illustration Technician, to determine adequate quality, 107 images were included in the study. Reference frame analysis was completed to orientate the images in a standardised manner. A landmark based approach was used by a single examiner positioning 8 mid and 7 bilateral facial landmarks and the analysis was applied using Vultus software (version 2.5.0.1). Intra and inter-reliability of landmark positioning were completed prior to data collection. Results: Fifty-seven males and 50 females were included with a mean age of 7.36 years (SD 3.74). The majority of the sample was White British (82.2%). The median asymmetry indices (AI) for midfacial landmarks were all < 1.10mm (25th and 75th IQR ranged from 0.24 to 1.75) and for bilateral facial landmarks were all < 2.60mm (25th and 75th IQR ranged from 0.63 to 3.65). Pogonion was the most asymmetric midfacial landmark (median AI 1.08mm, IQR 0.56, 1.75) and Cheilion was the most asymmetric bilateral facial landmark (median AI 2.56mm, IQR 1.69, 3.65). A statistically significant relationship between the side of nose and chin deviation (Chi-squared p=0.00) was detected and also a significant correlation between the severity of nose and chin deviation (Pearson's correlation 0.91). There was no significant difference in the asymmetry detected between males and females when the Mann-Whitney U test was applied. There was an association between increasing asymmetry and age for landmarks: Pronasale, Subnasale, Stomion, Pogonion and Christa philtri however this is potentially influenced by the size of the patient's head and thus should be interpreted with caution. Conclusions: In the standard population of children from the North West of England an element of facial asymmetry is present. The direction and magnitude of nose and chin deviation are highly correlated. Males and females exhibit equal levels of facial asymmetry.
12
Granillo, Nathan. "Three-Dimensional Photographic Evaluation of Immediate Soft Tissue Changes Following Rapid Maxillary Expansion." VCU Scholars Compass, 2011. http://scholarscompass.vcu.edu/etd/2504.
Full textAbstract:
The skeletal and dental changes associated with rapid maxillary expansion (RME) are well documented. Effects on the soft tissues and the potential impact on facial esthetics have not been well researched. The purpose of this study was to evaluate immediate changes in facial soft tissues as a result of RME by comparing threedimensional digital photogrammetric images before and after RME treatment. The 3dMDface System was used to obtain photographic images of 21 patients (mean age = 11.8 years) before and after RME treatment for transverse maxillary deficiency. A control group of 13 patients (mean age = 12.7 years) also had two images taken at a similar time interval. Mean expansion was 6.5 mm in the RME patients. Intercanthal distance, nose width, and intercommissural width changed significantly in the RME patients from T0 to T1 (P = 0.011, P = 0.050, and P = 0.003, respectively). Intercommissural width, however, was the only measure that significantly changed as compared with the control group (P = 0.041). Changes in intercanthal distance and nose width were significantly related to the amount of expansion achieved (R2 = 0.428, P = 0.0013 and R2 = 0.501, P = 0.0003, respectively).
13
Bang, Won B. "Improving the strength of 3DP parts and development of controlled strength cellular structure investment casting shell." Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/38200.
Full textAbstract:
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1996.Includes bibliographical references (p. 79).
Three Dimensional Printing (3DP) is a rapid prototyping process that creates a three dimensional part directly from computer models by printing a sequence of two dimensional layers. In this research, the strength of 3DP parts were improved by using different "print styles" (the way binder is deposited on the powder bed in creating a 3DP part) for use in investment casting process. The print styles that were created optimized line to line interaction between the printed lines, binder overlap, and the amount of unprinted powder surrounding the printed features. The strength of the parts are measured in three different axes (X-fast, Y-slow, Z). The strength improved by factors of 2, 8, and 7 for the three different axes. A controlled strength cellular structure investment casting shell that enables the creation of a metal part without any stress related defects has been created. The ceramic shell has an open cell frame structure with thin inner shell where the metal casting is poured. The flexibility of the 3DP technology applied to controlled strength cellular structure investment casting shell will incorporate all the advantages of 3DP to investment casting (Sach 1992, ASME) as well as reduction in material consumption, controlled heat transfer, permeability, and of course controlled strength to eliminate stress related defects. The cellular structure ceramic mold is designed to withstand the pouring pressures of the molten metal and survive the handling during processing yet fail when the stresses from the contracting metal becomes excessive. The 3DP molds are usually 60% porous and cellular structure investment casting shells consist of only 35% of the 3DP material per volume. A controlled strength cellular structure investment casting shell is designed to fail when excessive stress is applied to the shell structure. The stress on the casting shell is caused by the shrinkage of the metal part. The controlled strength investment casting shell has an open cellular structure frame with a thin inner shell where the metal casting will form.
by Won B. Bang.
S.M.
14
Docherty, Paul Henry. "Diastereocontrolled synthesis of hetero- and carbocycles via manganese(III) and copper(II) : towards a novel prostaglandin total synthesis." Thesis, University of Oxford, 2008. http://ora.ox.ac.uk/objects/uuid:6ca5556a-3d2d-454a-abbd-0a3a269c5724.
Full textAbstract:
The prostaglandins are a unique family of natural products found in all mammalian life, including humans. Their biological significance is profound, and they are responsible for a vast array of bodily functions. This importance, coupled with their low concentration in vivo, has made them attractive targets for total chemical synthesis. The work herein describes synthetic efforts towards their synthesis using an oxidative radical cyclisation to construct the key [3.3.0]-bridged bicyclic lactone, from which the prostaglandin skeleton may be derived. Key to this was the development of manganese(III) acetate and copper(II) triflate as optimal reagents for this cyclisation of unsaturated malonate/malonic acid derivatives. To study this, several model substrates for this crucial cyclisation were synthesised, and their cyclisation analysed. Chapter 5 describes the design and synthesis of several model substrates containing malonate groups for the oxidative radical cyclisation. The results of the cyclisation with manganese(III) and various copper(II) salts influenced the design of the substrates, and led to the use of malonic acids as more effective substrates for the formation of [3.3.0]-bicyclic lactones. A catalytic process, in which atmospheric oxygen is the terminal oxidant was also developed. Chapter 6 describes the studies towards a total synthesis of the prostaglandin family. Two potential routes are followed, the first of which used a key asymmetric epoxidation to install asymmetry. A Suzuki coupling was used to deliver the desired diene required for the cyclisation substrate, which was successfully cyclised using manganese(III) acetate and copper(II) triflate, creating the desired [3.3.0]-bicyclic lactone in good yield and with excellent diastereomeric control. A second, shorter route to the same lactone was also developed, using a novel asymmetric deconjugative aldol condensation to establish asymmetry. Cyclisation of this analogous substrate was also successful, delivering the same lactone after olefin metathesis.
15
Bednarkiewicz, Maroussia. "Summoning the believers as the Christians did? : religious differentiation in Muslim sources until the third/ninth century." Thesis, University of Oxford, 2017. http://ora.ox.ac.uk/objects/uuid:0e98bd5c-3d6d-4530-b372-95780de2af86.
Full textAbstract:
The Muslim tradition tells us that when Muslims migrated to Medina and their number increased, they felt the need for an efficient means to convoke the community for the daily prayers. Jews and Christians both had well-established summoning rituals involving different instruments, that Muslims considered adopting. They eventually developed a distinct, simple ritual consisting of a small set of chanted formulæ, which became known as the adhān, the Islamic call to prayer. This is the narrative thread that we find in all major Sunnī collections of aḥādīth - reported sayings of Muḥammad and his companions - which recount the introduction of the adhān. The present work postulates that this thread or 'proto-narrative' was used by several narrators, transmitters, and collectors until the third/ninth century who modified it and added new elements in order to settle political and religious controversies of their times. This proto-narrative is outlined in the main chapter (chap. 3), which highlights how it was modified and why, using close textual analysis of both Sunnī and Shī'ī texts with data-dense graphs of relations, locations, and times produced via network visualisation tools. Five major Sunnī legal treaties from the second/eighth century onwards were also scrutinised (chap. 4) to better understand the general context in which the aḥādīth about the introduction of the adhān were being circulated and confirm the results obtained through the textual analysis. The conclusions reveal specific mechanisms used in the formation and transmission of aḥādīth. In the case of the adhān, aḥādīth represent half of a 'conversation' between people, students, or rulers on one side, asking questions about the origins and the right form of the call to prayer, and on the other side, scholars or jurists who answer with adapted narratives. Only the latter was preserved, yet the present thesis shows that it is often possible to reconstruct, to a certain extent, the former part of this 'conversation'.
16
Shei, Shaun. "A model-driven approach towards designing and analysing secure systems for multi-clouds." Thesis, University of Brighton, 2018. https://research.brighton.ac.uk/en/studentTheses/53c11a93-3d8d-4cbe-82df-deb34be6ab1f.
Full text
17
Lübben, Jens. "The Role of Hydrogen Atoms and Thermal Displacement Parameters in Crystal Structure Refinement." Doctoral thesis, Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2017. http://hdl.handle.net/11858/00-1735-0000-0023-3DFD-0.
Full text
18
Lange, Katharina [Verfasser], Andreas [Akademischer Betreuer] Hagendorff, thomas [Gutachter] kahn, and gerhard [Gutachter] schuler. "Multidimensionale Darstellung der proximalen RCA in 3D4D- Technik im Vergleich zur Koronarangiographie / Katharina Lange ; Gutachter: thomas kahn, gerhard schuler ; Betreuer: Andreas Hagendorff." Leipzig : Universitätsbibliothek Leipzig, 2014. http://d-nb.info/1238692125/34.
Full text
19
Ables, David C. (David Christopher) 1973. "Design of a slurry layer forming station and improved fluid handling system for raster processes in 3DP®." Thesis, Massachusetts Institute of Technology, 2001. http://hdl.handle.net/1721.1/8545.
Full textAbstract:
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2001.Includes bibliographical references (leaves 189-190).
Three-Dimensional Printing (3DPTM) is a rapid-manufacturing process originally developed at MIT for building parts directly from CAD-generated models. Parts are fabricated in "slices" by creating a complete layer of powder and then selectively joining powder particles with a polymer binder deposited using a moving printhead. Traditional 3DPTM builds layers by spreading dry powder and prints binder using a rastering scheme with a continuous-jet printhead. For smaller parts and greater accuracy, a variation on the process called slurry 3DPTM (s3DPTM) uses raster-built slurry layers and a vector-printing scheme with a drop on demand (DoD) printhead. This here thesis presents efforts to improve core technology in both dry-powder 3DPTM and slurry 3DPTM. One of the most critical steps in s3DPTM is the building of the slurry layers. To avoid intra- and interlayer defects the slurry layer must be rastered at high deposition rates to promote line merging and better layer quality. The difficulty lies in the design of a machine capable of oscillating the slurry nozzle at the required frequencies. Fortunately, such a design was completed and the machine built as part of a collaborative effort with TDK Japan to build an s3DPTM machine for manufacturing small parts. The design uses a reciprocating countermass strategy to recycle mechanical energy and eliminate troublesome vibrations. A general overview of this slurry layer forming station (LFS) is given, along with an in-depth treatment of several components, including the forcers, centering system, and interface software. And speaking of rastering, dry-powder 3DPTM relies on this strategy for printing binder, just as the LFS uses a raster method to build powder layers. Beginning with observations made during the design of the LFS, the fluid-handling system was redesigned to improve binder droplet stream stability during the carriage traverse and turnaround. The improvement was made possible by repositioning a smaller version of the "Clamshell" constant pressure vessel used to set the fluid flow rate to the printhead carriage itself and using a closed-loop control system to maintain a constant fluid level in the Clamshell. Drawings, parts lists, schematic diagrams, and assembly instructions are included for building additional fluid control systems.
by David C. Ables.
S.M.
20
Lee, Paul Chong Chan. "A QUALITATIVE AND QUANTITATIVE ANALYSIS OF SOFT TISSUE CHANGE EVALUATION BY ORTHODONTISTS IN CLASS II NON EXTRACTION ORTHODONTIC TREATMENT USING THE 3dMD SYSTEM." Master's thesis, Temple University Libraries, 2013. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/217032.
Full textAbstract:
Oral BiologyM.S.
With the advent of cephalometrics in the 1930s, numerous studies have focused on the profile of a face to achieve a more esthetic orthodontic treatment outcome. With such heavy emphasis on facial esthetics, a shift in focus from the profile view to the oblique view has become necessary as the smile in the oblique view is what the general public evaluates. The purpose of this pilot study was to determine whether the current tools for diagnosis and treatment evaluation are sufficient. Currently, 2-dimensional composite photographs are utilized in evaluating the soft tissue. At Temple University, 3-dimensional images, which show all sides of the patient's face, are used adjunctively to 2-dimensional composite photographs. In this study, faculty members at the Temple University Department of Orthodontics were asked to complete surveys after viewing two different image modalities, 2-dimensional images and a 3-dimensional video of the same patient. They were asked to fill out the soft tissue goals for specific facial landmarks. Patient photos were in the smiling view as current literature lacks studies on this view. Faculty members' responses from analyzing the 2-dimensional images and 3-dimensional video for each patient were compared to determine which areas had frequent discrepancies from using two different image modalities. During the survey, a voice recorder captured any comments regarding the images. The ultimate goal of this qualitative pilot study was to identify when 3-dimensional imaging is necessary in treatment planning and evaluation, with an added hope to further advance research in 3-dimensional imaging and its vast possibilities to advance the field of orthodontics. Based on the data collected, the following conclusions were made: 1. The qualitative data highlighted that 3-dimensional imaging would be necessary in cases with skeletal deformities. 2. In the oblique view, 3-dimensional imaging is superior than 2-dimensional imaging by showing more accurate shadow, contour, and depth of the soft tissue. 3. Further improvement is necessary to create a virtual patient with treatment simulation abilities. 4. The comfort level among orthodontists of 2-dimensional imaging was higher than 3-dimensional imaging. With more widespread use of 3-dimensional imaging, more orthodontists may gradually reach a higher comfort level in using this relatively new technology. 5. Faculty members expressed high willingness to use 3-dimensional imaging if improvement in new technology could allow for more manipulation and accurate soft tissue prediction. 6. 3-dimensional imaging is superior in its efficiency, quick capture time, and lack of need for multiple images. Implementation of 3-dimensional imaging could streamline the records process and help with practice efficiency without compromising the image quality. 7. Both patients and orthodontists may benefit from using 3-dimensional imaging. Patients can see an accurate representation of themselves and possibly view their own treatment simulation upon further improvement in current technology. Orthodontists would benefit with much more accurate images that may serve as the virtual patient. 8. Besides the exorbitantly high cost, faculty members thought that more advances were needed and the current benefit was not great enough to justify the investment. The results were consistent with other studies that used the oblique view in that the 2-dimensional oblique view lacks depth and does not provide adequate information. With further improvement in current 3-dimensional imaging, this technology can benefit orthodontists in visualizing their patients. In addition, patients can benefit by hopefully seeing a live and accurate simulation of themselves instantly as a virtual patient. With these benefits of 3-dimensional imaging, it may one day be the new standard in patient records in the field of orthodontics.
Temple University--Theses
21
Luthander, Rasmus. "Photovoltaic System Layout for Optimized Self-Consumption." Thesis, Uppsala universitet, Fasta tillståndets fysik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-203996.
Full textAbstract:
Most of the photovoltaic (solar cell) systems in Sweden today are installed on private houses and connected to the public grid. Photovoltaic (PV) power can be consumed directly in the house, called self-consumption, or fed in to the public grid. For the house owner self-consumed PV energy often has a higher economic value than sold excess PV energy, since the savings from not buying one kWh is larger than the income of selling one kWh. The self-consumption can be expressed as an absolute value; amount of produced/consumed kWh, or as a relative; absolute self-consumption divided with total PV production. The PV production and self-consumption were calculated on an hourly basis. In this Master thesis a MATLAB tool for calculating and optimizing the production, absolute and relative self-consumption and profit for PV systems with panels in one (1DPV), two or three directions (3DPV) was developed. The results show possibilities to increase especially the relative self-consumption with 3DPV. There is however no economic gain of using 3DPV instead of south-directed 1DPV for the studied case; a private house close to Västerås with a 1DPV system of 3360 W and variable electricity prices based on hourly Nord Pool Spot prices. The rated power of the inverter can be decreased with 3DPV compared to south-oriented 1DPV and still keep minimal production losses. A smaller inverter and other peripheral equipment such as cables might compensate for the lower yearly profit with 3DPV when calculating the payback period. Further studies of economic aspects and how to optimize them have to be carried out for 3DPV systems, since economy is very crucial for investment decisions.
22
Mitchell, Tami Lee. "A New Method for the Examination of Policy Systems of Systems." Diss., Virginia Tech, 2011. http://hdl.handle.net/10919/29506.
Full textAbstract:
This dissertation examines multi-agency policy environments as a policy system of systems (SoS). The research conducted for this dissertation establishes the need to develop a method of analysis suitable for the analysis of a policy SoS that allows for the examination of individual policy relationships while maintaining a holistic perspective of the entire SoS. The Three-Dimensional Policy Design Structure (3DPDS) is proposed as a method of analysis suitable for examination of a policy SoS. This dissertation focuses on application of the 3DPDS to three specific areas of space launch policy that impact space launch capacity: (1) policies related to space launch vehicles, (2) policies related to space launch facilities, and (3) the potential impacts of the cancellation of the Ares 1 launch vehicle. The first two applications of the 3DPDS provide a retrospective analysis of the policy relationships within the space launch policy SoS. The final application uses the results of the examination of policies related to space launch vehicles to systematically examine a current issue. The results of the first two applications, when compared against data gathered from subject matter experts during the interview process, provided a much more complete and holistic perspective of the policy relationships within the SoS, including identification of policy outliers. The third application enabled a systematic review of a current policy issue that incorporated information from formal policy documents with information provided by subject matter experts during the interview process.Ph. D.
23
Abou, Hassana R. H. "Using e-learning to improve the effectiveness of teaching primary school ICT." Thesis, Coventry University, 2008. http://curve.coventry.ac.uk/open/items/c24990e3-e0d7-3dbd-c3e1-b520a3146c41/1.
Full textAbstract:
Economic, social, technological and educational factors have led to an increase in the use of ICT (Information and Communication Technology) in education at all levels. Most research concerning this has focused on the way in which e-learning can be used to improve teaching and learning across the curriculum and has neglected the teaching of ICT as a subject (Hammond, 2004). In a 1999 Ofsted inspection, ICT was found to be the least well taught subject in primary schools. The present research considers how the teaching of ICT could be better supported in the UK and Saudi Arabia. In the first stage, an investigation was made of the teaching of ICT in UK primary schools to understand why its teaching had been rated unfavourably. It was discovered that teaching focused on technical aspects (i.e. how to use specific applications) whilst ignoring the communication and information parts. Although it has been argued widely that e-learning improves teaching and learning across the curriculum, observations showed that e-learning was not, in itself, used to support teaching of the ICT curriculum. Hence, this research explored the ways in which the teaching of the ICT curriculum (to 9-11 year olds) could be made more effective, particularly through the incorporation of e-learning material. It was hypothesized that the experience of teaching and learning could be enhanced if e-learning material was designed which specifically addressed the needs of the teachers and young learners. Evidence collected in the course of the research suggested that little material existed to support the ICT curriculum, and that e-learning material produced to support other subjects does not always suit the teachers’ needs. Therefore in the second stage of the research, a design approach that engaged end users (teachers and young students) was proposed which was tested and refined during the design of e-learning material to support the teaching of the Multimedia Unit of the ICT National Curriculum. The resulting e-learning material was evaluated in UK schools to determine the extent to which it satisfied user needs and its effectiveness in teaching the intended learning outcomes. The results in both cases were positive implying that such a method could lead to the production of useful supportive material. As a former Saudi Arabian computer teacher, one of my personal goals was to provide opportunities to improve the experience of teachers and children in my own country. As such I have been interested in how I can transfer my understanding of the UK educational system to my home country. Following the successful evaluation of the elearning material in the UK, a demonstration of how a child centred design approach can be used to design effective educational material. Unfortunately although such a process might produce more effective learning outcomes and pleasurable material, I also found that such an approach is considered incompatible with commercial design environments. In the last stage of the thesis strategies are discussed which could be used (particularly in Saudi Arabia) to encourage the producers of educational materials to engage in the design of more effective teaching and learning experiences, especially in relation to the primary ICT curriculum. One such strategy would be to train undergraduates in applying a more user centred design approach as an integral part of their practice. The resultant design approach has now been approved by the Director of the Graphic Design Department in Dar Al Hekma Collage (Jeddah – Saudi Arabia) to be taught as a design approach for designing e-learning material for children on the Information Design Course. Additionally, a set of recommendations was developed for the Saudi Ministry of Education addressing the sort of revisions needed to improve the ICT curriculum in Saudi Arabia.
24
Rodriguez, Johnnatan, Kevin Hoefer, Andre Haelsig, and Peter Mayr. "Functionally Graded SS 316L to Ni-Based Structures Produced by 3D Plasma Metal Deposition." MDPI AG, 2019. https://monarch.qucosa.de/id/qucosa%3A34781.
Full textAbstract:
In this investigation, the fabrication of functionally graded structures of SS316L to Ni-based alloys were studied, using the novel technique 3D plasma metal deposition. Two Ni-based alloys were used, a heat resistance alloy Ni80-20 and the solid-solution strengthened Ni625. Different configurations were analyzed, for the Ni80-20 a hard transition and a smooth transition with a region of 50% SS316L/50% Ni80-20. Regarding the structures with Ni625, a smooth transition configuration and variations in the heat input were applied. The effect of the process parameters on the geometry of the structures and the microstructures was studied. Microstructure examinations were carried out using optical and scanning electron microscopy. In addition, microhardness analysis were made on the interfaces. In general, the smooth transition of both systems showed a gradual change in the properties. The microstructural results for the SS316L (both systems) showed an austenite matrix with δ-phase. For the mixed zone and the Ni80-20 an austenite (γ) matrix with some M7C3 precipitates and laves phase were recognized. The as-built Ni625 microstructure was composed of an austenite (γ) matrix with secondary phases laves and δ-Ni3Nb, and precipitates M7C3. The mixed zone exhibited the same phases but with changes in the morphology.
25
Mello, Silvia Teixeira de [UNESP]. "Influência do tipo e da técnica de aplicação de agente infiltrante na resistência mecânica de componentes produzidos por manufatura aditiva (3DP)." Universidade Estadual Paulista (UNESP), 2017. http://hdl.handle.net/11449/152037.
Full textAbstract:
Submitted by Silvia Teixeira de Mello null (silviateixmello@gmail.com) on 2017-10-26T21:23:12Z
No. of bitstreams: 1
DISSERTAÇÃO SILVIA MELLO 2017-3 CORRIGIDA 26-10.pdf: 3630355 bytes, checksum: 302fa9b705ffc11d7192a4b67392d0c6 (MD5)Approved for entry into archive by Monique Sasaki (sayumi_sasaki@hotmail.com) on 2017-10-31T18:59:52Z (GMT) No. of bitstreams: 1 mello_st_me_ilha.pdf: 3630355 bytes, checksum: 302fa9b705ffc11d7192a4b67392d0c6 (MD5)
Made available in DSpace on 2017-10-31T18:59:52Z (GMT). No. of bitstreams: 1 mello_st_me_ilha.pdf: 3630355 bytes, checksum: 302fa9b705ffc11d7192a4b67392d0c6 (MD5) Previous issue date: 2017-08-30
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Ao longo das duas últimas décadas, a contribuição da manufatura aditiva passou da confecção de um mero protótipo de um produto, no início de seu desenvolvimento, para a confecção de qualquer produto direto, presente em todos os setores industriais. Com este avanço, diferentes tecnologias da manufatura aditiva surgiram com o intuito de melhorar alguns parâmetros de produção. Neste meio, a tecnologia de impressão tridimensional 3DP, por consequência de suas várias características intrínsecas, se destaca para atender o setor biomédico, através da técnica de biomodelagem, que contribuem imensamente de forma didática e prática para a performance de cirurgias. Porém, há algumas limitações finais nas peças obtidas por esta tecnologia que devem ser contornadas, focando-se no tratamento adicional necessário destas peças, o pós-processamento, de modo a aprimorá-las, conferindo então sucesso ao destino destas. Neste trabalho, adotou-se a tecnologia de manufatura aditiva 3DP para estudar como a adição de diferentes agentes infiltrantes influenciam no acréscimo de densidade aparente e resistência mecânica de amostras feitas de componentes de gesso, constituídas por corpos de prova cilíndricos e prismáticos, de modo a simular a melhor composição para biomodelos. Para isto, o pós-processamento foi dividido em duas etapas. Na primeira etapa, foram aplicados separadamente nas amostras, quatro tipos de adesivos à base de etilcianocrilato, por gotejamento, e um à base de epóxi, por moldagem com pá. Já na segunda etapa, foram aplicados nas amostras, também separadamente, quatro tipos de adesivos à base de etilcianocrilato, por gotejamento e banho de imersão, e um à base de epóxi, por moldagem com pá. Além dos métodos de aplicação dos adesivos, as duas etapas se diferem também pelos binders utilizados para constituírem as amostras à base de gesso. Para ambas etapas, obteve-se o melhor resultado com o adesivo de cianocrilato de baixíssima viscosidade, capaz de provocar maiores variações de densidade aparente às amostras, além de maiores acréscimos de resistência.
Over the past two decades, the contribution of additive manufacturing has shifted from a mere prototype of a product at the beginning of its development to the production of any direct product present in all industrial sectors. With this advance, different technologies of the additive manufacturing appeared with the intention to improve some parameters of production. In this environment, three-dimensional printing 3DP technology, due to its various intrinsic characteristics, stands out to serve the biomedical sector through the biomodelling technique, which contribute immensely in a didactic and practical way for the performance of surgeries. However, there are some final limitations in the parts obtained by this technology that must be improved, focusing on the necessary additional treatment of these parts, the post-processing, in order to upgrade them, thus giving success to their destination. In this study, 3DP additive manufacturing technology was adopted to study how different infiltrating agents influence the increase in apparent density and mechanical strength of samples made of gypsum components, constituted by cylindrical and prismatic specimens, in order to simulate the best composition for biomodels. For this, the post-processing was divided in two stages. In the first stage, separately, four types of ethylcyanoacrylate-based adhesives were applied on the samples by dripping, and one epoxy-based adhesive was applied by shovel molding. In the second stage, also separately, four types of ethylcyanocrylate based adhesives were applied in the samples, by dripping and by dipping, and the epoxy-based, by shovel molding. Besides the adhesive application methods, the two stages also differ from the binders used to constitute the gypsum-based samples. For both stages, the best result was obtained by the cyanoacrylate adhesive with very low viscosity, capable of causing greater variations of apparent density and additions of strength to the samples.
26
Mello, Silvia Teixeira de. "Influência do tipo e da técnica de aplicação de agente infiltrante na resistência mecânica de componentes produzidos por manufatura aditiva (3DP) /." Ilha Solteira, 2017. http://hdl.handle.net/11449/152037.
Full textAbstract:
Orientador: Ruis Camargo TokimatsuResumo: Ao longo das duas últimas décadas, a contribuição da manufatura aditiva passou da confecção de um mero protótipo de um produto, no início de seu desenvolvimento, para a confecção de qualquer produto direto, presente em todos os setores industriais. Com este avanço, diferentes tecnologias da manufatura aditiva surgiram com o intuito de melhorar alguns parâmetros de produção. Neste meio, a tecnologia de impressão tridimensional 3DP, por consequência de suas várias características intrínsecas, se destaca para atender o setor biomédico, através da técnica de biomodelagem, que contribuem imensamente de forma didática e prática para a performance de cirurgias. Porém, há algumas limitações finais nas peças obtidas por esta tecnologia que devem ser contornadas, focando-se no tratamento adicional necessário destas peças, o pós-processamento, de modo a aprimorá-las, conferindo então sucesso ao destino destas. Neste trabalho, adotou-se a tecnologia de manufatura aditiva 3DP para estudar como a adição de diferentes agentes infiltrantes influenciam no acréscimo de densidade aparente e resistência mecânica de amostras feitas de componentes de gesso, constituídas por corpos de prova cilíndricos e prismáticos, de modo a simular a melhor composição para biomodelos. Para isto, o pós-processamento foi dividido em duas etapas. Na primeira etapa, foram aplicados separadamente nas amostras, quatro tipos de adesivos à base de etilcianocrilato, por gotejamento, e um à base de epóxi, por moldagem com... (Resumo completo, clicar acesso eletrônico abaixo)
Mestre
27
Freiman, Hannes. "Hur former leder nya spelare i 3D-spel : Hur former i en 3dD-spelmiljö hjälper nybörjarspelare att ta sig vidare i spel." Thesis, Uppsala universitet, Institutionen för speldesign, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-228211.
Full textAbstract:
Syftet med denna studie är att få en tydligare bild över hur former i en 3D-spelmiljö hjälper nybörjarspelare att ta sig vidare i spel. Denna studie utgick ifrån olika typer av forskning och artiklar angående liknande ämnen, från dessa gjordes en studie som baserades på en kvalitativ undersökning där fem testpersoner som aldrig spelat ett Förstapersons skjutspel (FPS-spel) förut fick svara på frågor som handlade om vägval i FPS-spel och sedan spela utvalda spel för att se hur de resonerade när de väl spelade dem. Denna studie utfördes med konstant övervakning för att lättare kunna se hur testspelarna reagerade på formerna i spelen. Den data och statistik som samlades under denna period sammanställdes sedan och medelvärden drogs ut från enkätundersökningen.Analysen av den data som samlades in via både enkätundersökningen och speltestet visade att de spel som undersöktes har en tendens att ha utvalda former placerade upprepade gånger efter den väg spelaren bör ta. Mjuka former är något som används för att leda en spelare; de sticker ut ur en miljö på så sätt att de inte uttrycker någon typ av fara i deras form, och blir därför vägledande. Detta används också repetitivt vilket studien visade vara något som spelarna reagerade på; de visste att de runda formerna tog en spelare vidare i spelvärlden. De slutsatser som kunde dras från denna studie är att även fast vissa former är missledande visar studien att former använts för att vägleda spelare och för att visa möjligheter i form av egen utforskning. De former som mest märkbart leder en spelare i de utvalda spelen är de former som sticker ut ifrån miljön, samt upprepade gånger placeras där spelaren bör gå. Det finns tydliga tecken på att dessa objekt med utstickande visuellt formspråk är placerade för att just visa spelaren vägen.Vägledning med former används i dessa spel och är ett stort hjälpmedel för nybörjarspelare.
28
Beckert, Barbara Verfasser], Christoph [Akademischer Betreuer] [Dittrich, and Heiko [Gutachter] Faust. "A post-frontier in transformation: land relations between access, exclusion and resistance in Jambi province, Indonesia / Barbara Beckert ; Gutachter: Christoph Dittrich, Heiko Faust ; Betreuer: Christoph Dittrich." Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2017. http://nbn-resolving.de/urn:nbn:de:gbv:7-11858/00-1735-0000-0023-3DBD-F-5.
Full text
29
Carlier, Emeric. "Development of 3D printed implants for subcutaneous administration of sustained-release antibodies." Doctoral thesis, Universite Libre de Bruxelles, 2021. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/326756.
Full textAbstract:
Thèse réalisée dans le cadre d'une collaboration avec UCB Pharma et la région Wallonne s'inscrivant dans le cadre du projet SAS. Le but de ce projet était de développer des implants sous-cutanés imprimés en trois dimensions pour permettre une libération d’anticorps thérapeutique de manière prolongée au cours du temps. En effet, les thérapies disponibles sont souvent administrées par voie intraveineuse, ce qui peut réduire la compliance des patients dû à l’inconfort et à la fréquence de ces administrations. Les systèmes de délivrance, tels que des implants, peuvent limiter les fréquences d’administration grâce à l’insertion d’un dispositif qui libèrera le principe actif au cours du temps durant une période donnée. Les implants s’inscrivent comme une alternative aux microsphères qui sont également des dispositifs développés et investigués en vue de favoriser l’adhésion et la compliance des patients. L’avènement du 3D dans le milieu pharmaceutique a montré une certaine frénésie liée au développement de la médecine personnalisée et à l’innovation du procédé dans ce secteur. La sélection d’un matériau biocompatible et biorésorbable tel que le PLGA représente une véritable plus-value dans le développement d’implant. Etant donné que ces implants sont biodégradables, le retrait n’est pas à envisager, ce qui limite les désagréments du patient à un seul acte chirurgical lors de l’implantation. Au cours de ce travail, une approche pragmatique a d’abord été abordée sur les procédés d’extrusion à chaud et de l’impression 3D en utilisant un polymère couramment employé dans l’impression grand public, le PLA. L’investigation des paramètres d’impressions (température d’impression, epaisseur de couche et vitesse d’impression) et l’usage de divers plastifiants (la triacétine (TA), le polyethylène glycol 400 (PEG 400), le citrate de triéthyle (TEC) et l’acétyle citrate de triéthyle (ATEC)) pour faciliter les procédés à chaud et dans l’idée de réduire les températures d’extrusion et d’impression du matériau ont été évalués. Ces essais ont démontré l’effet de la température d’impression sur la qualité de l’impression et principalement sur les propriétés du matériau comme la force de traction et la ductilité. De plus, l’ajout de plastifiant à la matrice du PLA a permis de diminuer sa température de transition vitreuse. Par exemple, la température de transition vitreuse du PLA a été diminuée de 53 °C à 34 °C par l’ajout de PEG 400. Cette approche avait pour but d’évaluer la possibilité de diminuer les températures d’impression dans l’optique d’encapsuler à chaud un anticorps sensible à la chaleur pour la suite de ce travail.Ensuite, le développement de filaments imprimables contenant des anticorps a été abordé et mis en place à l’aide d’un modèle d’anticorps polyclonal disponible en grandes quantités et à des coûts relativement faibles. Un anticorps à l’état solide a été favorisé dans le procédé car il est largement accepté que les protéines sous forme solide sont plus stables au cours du temps en comparaison aux solutions d’anticorps. De plus, cet état solide facilite les manipulations précédant l’extrusion comme l’étape de mélange. Pour la réalisation des filaments, différents types de PLGA ont été investigués afin d’atteindre les propriétés nécessaires à l’impression en termes de diamètre mais également de comportement physique. Ces dérivés étaient caractérisés par des masses moléculaires différentes comme pour le PDLG5004 (44 kDa), le RG502 (7-17 kDa) et parmis eux, un copolymère PEG-PLGA (2 kDa-20 kDa). Un PLGA de faible masse moléculaire a été sélectionné pour développer ce filament. En effet, les extrusions étaient réalisables à une température maximum de 90 °C et les impressions à 113 °C minimum. L’un des enjeux cruciaux du développement de filament imprimable contenant un anticorps à haute concentration, au minimum 15% (w/w), était d’en assurer l’homogénéité. Cependant, l’usage de températures aussi élevées lors de l’impression a induit la dégradation de l’anticorps par la formation d’agrégats et principalement de fragments. Ces derniers sont généralement produits lors de procédé à haute température ou par l’usage de conditions drastiques telles que l’acidification du milieu. Cette plateforme a été adaptée à l’encapsulation d’anticorps thérapeutique fournit par UCB Pharma. L’usage d’un anticorps monoclonal possédant une stabilité supérieure à celle du modèle initialement utilisé permettrait d’identifier l’impact du procédé sur l’intégrité de l’anticorps. La formulation de l’anticorps a été réalisée en utilisant différents stabilisants conventionnels (sucrose (Suc), trehalose (Tre), 2-Hydroxypropyl-beta-cyclodextrine (HP-β-CD), inuline (Inu) et sorbitol (Sor)) et reconnus pour la stabilisation des protéines. A côté des excipients ajoutés, différentes quantités d’excipients ont été investigués. Ces manipulations ont montré que la stabilité de l’anticorps était privilégiée à l’aide du sucrose et du tréhalose à un ratio anticorps monoclonal:excipient de 2.0:1. En gardant ce ratio, l’ajout d’un acide aminé (leucine) aux deux disaccharides précédemment cités, a amélioré la stabilité de l’anticorps vis-à-vis des procédés à chaud (extrusion et impression 3D). L’homogénéité au sein des filaments imprimables et des pièces 3D a été confirmée tout au long du procédé. En effet, les charges en anticorps étaient similaires à la charge théorique de 15% (w/w). Aucune fragmentation de l’anticorps n’a été observée à l’issue des procédés à chaud. Cependant, une augmentation des agrégats de 2.6% en solution à 3.6% après impression 3D a été constatée à la fin du processus. Après avoir stabilisé l’anticorps, le but premier étant d’en promouvoir une libération prolongée au cours du temps. Les profils ont révélé une libération en trois phases au cours du temps mais avec un relargage après 24h relativement faible (< 5%) dû à la densité des matrices polymériques. Ensuite, la dégradation du polymère représente l’élément limitant la libération de l’anticorps au cours du temps. En effet, l’érosion du polymère joue un rôle clé dans la libération de l’anticorps encapsulé. La libération au cours du temps a été démontrée sur une période allant jusqu’à 15 semaines. La stabilité de l’anticorps dans le milieu de dissolution a été évaluée et une dégradation de celui-ci au cours du temps a été observée. Cette dégradation est principalement liée à l’érosion du polymère et à l’acidification du milieu au cours du test de dissolution. Après avoir optimisé la formulation de l’anticorps et avoir démontré la libération prolongée de celui-ci, son affinité restait à être étudiée. La capacité de l’anticorps à se lier à sa cible a pu être démontrée après 24h de dissolution mais cette affinité s’est réduite au cours de la durée de la dissolution avec une augmentation de l’agrégation et de la fragmentation de l’anticorps. Une étude de stabilité a également démontré que les implants imprimés en 3D sont stables à une température 5 °C sur une durée de 6 mois. Aucun élément de dégradation n’a été observé au cours du temps et l’affinité de l’anticorps a été préservée au cours de l’étude. Finalement, cette plateforme a également été évaluée pour l’encapsulation d’une troisième molécule biologique, un fragment d’anticorps monoclonal, pour d’une part en estimer la stabilité et l’applicabilité et d’autre part envisager une prochaine étude pré-clinique sur rongeurs. Le fragment d’anticorps a montré une stabilité supérieure à celle de l’anticorps monoclonal avec une faible agrégation après l’extrusion et l’impression. La libération prolongée du fragment a été évaluée sur 8 semaines et une libération du fragment de 79% a été observée avec une formulation contenant du tréhalose et de la leucine. En effet, les fragments d’anticorps ont une demi-vie plasmatique relativement faible, de l’ordre de 28 minutes, ce qui donne tout son sens à des systèmes à libération prolongée. Pour finir, la réalisation d’une étude pré-clinique permettrait de valider le modèle. En conclusion, ce travail a démontré la faisabilité de l’usage de l’impression 3D en vue de développer des systèmes à libération prolongée contenant des anticorps et en utilisant des procédés à hautes températures. Ces implants ont été caractérisés par une stabilité favorable et une libération intéressante qui feront l’objet d’investigation lors d’études pharmacocinétiques.Doctorat en Sciences biomédicales et pharmaceutiques (Pharmacie)
info:eu-repo/semantics/nonPublished
30
Albaiji, Naif Faleh S. "Repeatability Case Study of the 3D Printer in the School of Engineering and Applied Science Lab." TopSCHOLAR®, 2018. https://digitalcommons.wku.edu/theses/2359.
Full textAbstract:
3DP (three-dimensional printing) technologies have become more than just a tool to help companies with prototyping and designing in the pre-production stage. Some firms have already implemented 3DP technology to produce parts and end-use products. However, there are several challenges and barriers that this technology must overcome to replace traditional manufacturing methods. One of the most significant obstacles associated with 3D printing is its low level of accuracy in variable repeatability when it comes to making separate batches of the same product. There are several arguable reasons behind this variation. Some of the factors that can influence repeatability are the type of material, the design, the type of product produced, and the orientation, or the location of the build inside the building envelope. The goal of this study was to determine whether the location of the build inside the surface area of the working envelope can affect the properties (height, width, depth, and weight) of the product.
Western Kentucky University (WKU) provides students with a few 3D printers on campus. One of those printers, a Stratasys (model: BST 768/SST 768), is in the Senator Mitch McConnell Advanced Manufacturing and Robotics Laboratory. The researcher used this printer for the study to determine if the location of the printer influenced the final product. The conclusion of the research did reveal that the printing location does affect the quality of the final product.
31
Hansen, Andrew. "Perception of Differences in Lip Profile between 2-D and 3-D." VCU Scholars Compass, 2016. http://scholarscompass.vcu.edu/etd/4142.
Full textAbstract:
Past studies evaluating the esthetics of orthodontic treatment have been done using 2-D images. New 3-D imaging offers an improved, real-life representation of a subject. The purpose of this study was to determine how laypeople perceived differences in lip position (flat versus ideal lip fullness) in 2-D compared to 3-D.
3dMD images of 8 Caucasian subjects were adjusted to an ideal and flat lip position in 3-D and then in 2-D from the profile view. 2 surveys were created with paired ideal and flat images on the screen, either in 2-D or 3-D, and evaluators were asked to choose which image they preferred and by how much.
Evaluators were more likely to be neutral, and were less decisive of their preference in 3-D compared to 2-D. People might be less sensitive to small differences in facial soft tissue and esthetics than previous research in 2-D has led orthodontists to believe.
32
Baydemir, Tuncay. "Effect Of Natural Polysaccharides On The Integrity And Texture Of Sugar Based Matrices In Three Dimensional Printing." Master's thesis, METU, 2003. http://etd.lib.metu.edu.tr/upload/4/1045392/index.pdf.
Full textAbstract:
Three dimensional printing (3DP) is one of the most important solid freeform
fabrication (SFF) methods that can produce any material with desired 3D
shape by using suitable powder-binder formulations. It differs from the standard
molding operations in that it can produce a complicated shapes by a software
driven instrument in a laminated fashion and the cost is lower. This method can be applied in a very wide area including drug release operations, biomaterial
production especially for bone fixation, prototype production for all purposes,
wound dressing etc. It can also be used in obtaining edible objects by using natural polysaccharides with water based binders.
In this study, it is aimed to understand the gelling behaviour of some of the
gelling materials, which are alginates, pectins and carageenans, and effect of
various factors on the production of confectionary objects by means of 3DP
process. Effect of multivalent cations, especially Ca2+ ion, on the gelling behaviour of these materials are investigated. The egg-box structure obtained between the polymer segments increases the water holding capacity of the materials and much more chewy structures can be obtained. The molecular changes are followed by
Fourier Transform infrared spectroscopy (FTIR). In 3DP applications, the
composition of powder and binder, pH, temperature, relative humidity (RH) and
machine parameters are important factors affecting the texture of the final object.
The texture of the produced specimens is examined by using a texture analyzer and maximum force values are given as g/cm at failure. Alginate and carrageenans are found to be more effective in obtaining chewy textures with Ca2+ ion content in sugar based matrices and optimization of machine parameters are performed to
obtain a higher resolution on the specimens.
33
Palmer, Andrew. "The Design and Development of an Additive Fabrication Process and Material Selection Tool." Master's thesis, University of Central Florida, 2009. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3635.
Full textAbstract:
In the Manufacturing Industry there is a subset of technologies referred to as Rapid Technologies which are those technologies that create the ability to compress the time to market for new products under development . Of this subset, Additive Fabrication (AF), or more commonly known as Rapid Prototyping (RP), acquires much attention due to its unique and futuristic approach to the production of physical parts directly from 3D CAD data, CT or MRI scans, or data from laser scanning systems by utilizing various techniques to consecutively generate cross-sectional layers of a given thickness upon the previous layer to form 3D objects. While Rapid Prototyping is the most common name for the production technology it is also referred to as Additive Manufacturing, Layer Based Manufacturing, Direct Digital Manufacturing, Free-Form Fabrication, and 3-Dimensional Printing. With over 35 manufacturers of Additive Fabrication equipment in 2006 , the selection of an AF process and material for a specific application can become a significant task, especially for those with little or no technical experience with the technology and to add to this challenge, many of the various processes have multiple material options to select from . This research was carried out in order to design and construct a system that would allow a person, regardless of their level of technical knowledge, to quickly and easily filter through the large number of Additive Fabrication processes and their associated materials in order to find the most appropriate processes and material options to create physical reproductions of any part. The selection methodology used in this paper is a collection of assumptions and rules taken from the author's viewpoint of how, in real world terms, the selection process generally takes place between a consumer and a service provider. The methodology uses those assumptions in conjunction with a set of expert based rules to direct the user to a best set of qualifying processes and materials suited for their application based on as many or as few input fields the user may be able to complete.M.S.
Department of Industrial Engineering and Management Systems
Engineering and Computer Science
Industrial Engineering MS
34
Cashman, Mark Francis. "Siloxane-Based Reinforcement of Polysiloxanes: from Supramolecular Interactions to Nanoparticles." Thesis, Virginia Tech, 2020. http://hdl.handle.net/10919/100134.
Full textAbstract:
Polysiloxanes represent a unique class of synthetic polymers, employing a completely inorganic backbone structure comprised of repeating –(Si–O)n– 'siloxane' main chain linkages. This results in an assortment of diverse properties exclusive to the siloxane bond that clearly distinguish them from the –(C–C)n– backbone of purely organic polymers.
Previous work has elucidated a methodology for fabricating flexible and elastic crosslinked poly(dimethyl siloxane) (PDMS) constructs with high Mc through a simultaneous crosslinking and chain-extension methodology. However, these constructs suffer the poor mechanical properties typical of lower molecular weight crosslinked siloxanes (e.g. modulus, tear strength, and strain at break). Filled PDMS networks represent another important class of elastomers in which fillers, namely silica and siloxane-based fillers, impart improved mechanical properties to otherwise weak PDMS networks. This work demonstrates that proper silicon-based reinforcing agent selection (e.g. siloxane-based MQ copolymer nanoparticles) and incorporation provides a synergistic enhancement to mechanical properties, whilst maintaining a low viscosity liquid composition, at high loading content, without the use of co-solvents or heating. Rheological analysis evaluates the viscosity while photorheology and photocalorimetry measurements evaluate rate and extent of curing of the various MQ-loaded formulations, demonstrating theoretical printability up to 40 wt% MQ copolymer nanoparticle incorporation. Dynamic mechanical analysis (DMA) and tensile testing evaluated thermomechanical and mechanical properties of the cured nanocomposites as a function of MQ loading content, demonstrating a 3-fold increase in ultimate stress at 50 wt% MQ copolymer nanoparticle incorporation. VP AM of the 40 wt% MQ-loaded, photo-active PDMS formulation demonstrates facile amenability of photo-active PDMS formulations with high MQ-loading content to 3D printing processes with promising results.
PDMS polyureas represent an important class of elastomers with unique properties derived from the synergy between the nonpolar nature, unusual flexibility, and low glass transition temperature (Tg) afforded by the backbone siloxane linkages (-Si-O)n- of PDMS and the exceptional hydrogen bond ordering and strength evoked by the bidentate hydrogen bonding of urea. The work herein presents an improved melt polycondensation synthetic methodology, which strategically harnesses the spontaneous pyrolytic degradation of urea to afford a series of PDMS polyureas via reactions at high temperatures in the presence of telechelic amine-terminated oligomeric poly(dimethyl siloxane) (PDMS1.6k-NH2) and optional 1,3-bis(3-aminopropyl)tetramethyldisiloxane (BATS) chain extender. This melt polycondensation approach uniquely circumvents the accustomed prerequisite of isocyanate monomer, solvent, and metal catalysts to afford isocyanate-free PDMS polyureas using bio-derived urea with the only reaction byproduct being ammonia, a fundamental raw ingredient for agricultural and industrial products.
As professed above, reinforcement of polysiloxane materials is ascertained via the incorporation of reinforcing fillers or nanoparticles (typically fumed silica) or blocky or segmented development of polymer chains eliciting microphase separation, in order to cajole the elongation potential of polysiloxanes. Herein, a facile approach is detailed towards the synergistic fortification of PDMS-based materials through a collaborative effort between both primary methods of polysiloxane reinforcement. A novel one-pot methodology towards the facile, in situ incorporation of siloxane-based MQ copolymer nanoparticles into segmented PDMS polyureas to afford MQ-loaded thermoplastic and thermoplastic elastomer PDMS polyureas is detailed. The isocyanate-free melt polycondensation achieves visible melt dispersibility of MQ copolymer nanoparticles (good optical clarity) and affords segmented PDMS polyureas while in the presence of MQ nanoparticles, up to 40 wt% MQ, avoiding post-polymerization solvent based mixing, the only other reported alternative. Incorporation of MQ copolymer nanoparticles into segmented PDMS polyureas provides significant enhancements to modulus and ultimate stress properties: results resemble traditional filler effects and are contrary to previous studies and works discussed in Chapter 2 implementing MQ copolymer nanoparticles into chemically-crosslinked PDMS networks. In situ MQ-loaded, isocyanate-free, segmented PDMS polyureas remain compression moldable, affording transparent, free-standing films.Master of Science
Polysiloxanes, also referred to as 'silicones' encompass a unique and important class of polymers harboring an inorganic backbone. Polysiloxanes, especially poly(dimethyl siloxane) (PDMS) the flagship polymer of the family, observe widespread utilization throughout industry and academia thanks to a plethora of desirable properties such as their incredible elongation potential, stability to irradiation, and facile chemical tunability. A major complication with the utilization of polysiloxanes for mechanical purposes is their poor resistance to defect propagation and material failure. As a result polysiloxane materials ubiquitously observe reinforcement in some fashion: reinforcement is achieved either through the physical or chemical incorporation of a reinforcing agent, such as fumed silica, or through the implementation of a chemical functionality that facilitates reinforcement via phase separation and strong associative properties, such as hydrogen bonding. This research tackles polysiloxane reinforcement via both of these strategies. Facile chemical modification permits the construction PDMS polymer chains that incorporate hydrogen bonding motifs, which phase separate to afford hydrogen bond-reinforced phases that instill vast improvements to elastic behavior, mechanical and elongation properties, and upper-use temperature. Novel nanocomposite formulation through the incorporation of MQ nanoparticles (which observe widespread usage in cosmetics) facilitate further routes toward improved mechanical and elongation properties. Furthermore, with growing interest in additive manufacturing strategies, which permit the construction of complex geometries via an additive approach (as opposed to conventional manufacturing processes, which require subtractive approaches and are limited in geometric complexity), great interest lies in the capability to additively manufacture polysiloxane-based materials. This work also illustrates the development of an MQ-reinforced polysiloxane system that is amenable to conventional vat photopolymerization additive manufacturing: chemical modification of PDMS polymer chains permits the installation of UV-activatable crosslinking motifs, allowing solid geometries to be constructed from a liquid precursor formulation.
35
Hajhashem, Mohammad. "Enabling the diffusion of disruptive innovations in medical markets : case of Iranian cardiovascular devices market." Thesis, University of Manchester, 2015. https://www.research.manchester.ac.uk/portal/en/theses/enabling-the-diffusion-of-disruptive-innovations-in-medical-marketscase-of-iranian-cardiovascular-devices-market(b14b79dd-3d4d-4b7c-845a-af131c9b639d).html.
Full textAbstract:
Following the studies of technology trajectories, Christiansen (1997) coined the concept of disruptive innovation to shed more light on the pattern of discontinuous innovations which were introducing new performance values to the market and mostly led to create a new market. Following his studies there have been a huge amount of scholars who have tried to elucidate the concept of disruptive innovations from different points of views. Among all of these studies, there are few researches about the dynamic of disruptive innovations diffusion in the market while most of the studies have focused on the concept itself. According to Porter (2008) the dynamic of market competition has been totally changed over the past decade and survivance of incumbents in the market mostly depends on their capability to innovate disruptively and keep their dominancy by radical or incremental improvements. Considering the desire of incumbents to set a dominant position in today’s fast growing markets, getting the ultimate benefits of disruptive innovations has become a disputable issue. Therefore, focusing on the dynamic of disruptive innovations, this research tries to elucidate the way that market leaders take an unknown potential disruptive innovation out of its dark corner during its infancy time, raise it and disrupt the mainstream market relying on it to establish a new market. Focusing on the dynamic of innovation diffusion, this research has chosen the high-tech medical market of Iran as the main target of empirical field work. Novelty of this concept in medical markets and also appropriateness of invasive cardiovascular devices business in terms of great amount of disruptive innovation, make this case study appropriate for the purpose of this research. Therefore conducting a longitude case study of Iranian invasive cardiovascular market during the past 10 years, this research conducts 30 semi-structured interviews with the key decision makers of the four main incumbents of Iranian invasive cardiovascular market about launching new innovations including: Johnson and Johnson (Cordis), Abbott Laboratories, Boston Scientific and Medtronic. The findings of these interviews are supported by the results of archival researches for more validity and reliability. Finally these findings will get compared with the conceptual framework of research in the discussion chapter to modify the existing literatures and in some cases add some new theoretical notions to them. The main contribution of this research is to identify the accelerating factors of disruptive innovation diffusion from, strategic, technological and cultural points of views. These findings can help practitioners to accelerate the diffusion rate of their disruptive innovations to disrupt the market earlier than the others and set their dominant position in the market as a market leader. Also it will provide an opportunity for the other scholars to build on more about the concept of disruptive innovation diffusion.
36
Vitry, Pauline. "Applications and development of acoustic and microwave atomic force microscopy for high resolution tomography analysis." Thesis, Dijon, 2016. http://www.theses.fr/2016DIJOS046/document.
Full textAbstract:
La microscopie à force atomique (AFM) est un outil de caractérisation d’échantillons tant organiques qu’inorganiques d’intérêt en physique, en biologie et en métallurgie. Le champ d’investigation de la microscopie AFM reste néanmoins restreint à l’étude des propriétés surfaciques des échantillons et la caractérisation sub-surfacique à l’échelle nanométrique n’est pas envisageable au-delà de la nano-indentation. Lors de ce travail, nous nous sommes intéressés à deux techniques de sonde locale complémentaires pour l’investigation volumique haute résolution.La première technique proposée est la microscopie de champ proche ultrasonore (MS-AFM), mise en place et exploitée en collaboration avec Dr. L. Tétard de l’Université Centrale de Floride. Cette technique fournie des informations localisées en profondeur en utilisant des ondes acoustiques dans la gamme de fréquences du MHz. Une étude complète de l’influence des paramètres de fréquences a été réalisée sur des échantillons de calibration et a permis de valider un modèle d’interprétation numérique. Cette technique ultrasonore, non invasive, a été appliquée à la caractérisation de vésicules lipidiques au sein de bactéries lors d’une collaboration avec les Pr. A. Dazzi et M.-J. Virolle, de l’Université Paris Sud Orsay. Un couplage a été réalisé avec la microscopie AFM infra-rouge (AFM-IR). Cette étude a démontré le potentiel d’investigation et d’analyse volumique et chimique d’échantillons biologiques.La seconde technique étudiée est la microscopie micro-onde (SMM), développée en collaboration avec la société Keysight. Cette technique, tout comme la microscopie acoustique, est non invasive et conduit à une caractérisation physico-chimique basée sur l’interaction de micro-ondes (0.2-16 GHz) avec la matière. Dans le cas de métaux, un lien entre la fréquence et la profondeur d’investigation a été mis en évidence. Cette technique a été appliquée à l’étude de la diffusion d’élément chimique léger au sein de métaux et à la mesure des propriétés mécaniques des matériaux. L’ensemble de ces résultats ouvre un nouveau champ d’investigation de la tomographie 3D dans l’analyse volumique à l’échelle nanométrique que ce soit dans le domaine de la biologie ou de la métallurgieThe atomic force microscope (AFM) is a powerful tool for the characterization of organic and inorganic materials of interest in physics, biology and metallurgy. However, conventional scanning probe microscopy techniques are limited to the probing surface properties, while the subsurface analysis remains difficult beyond nanoindentation methods. Thus, the present thesis is focused on two novel complementary scanning probe techniques for high-resolution volumetric investigation that were develop to tackle this persisting challenge in nanometrology. The first technique considered, called Mode Synthesizing Atomic Force Microscopy (MSAFM), has been exploited in collaboration with Dr. Laurene Tetard of University of Central Florida to explore the volume of materials with high spatial resolution by means of mechanical actuation of the tip and the sample with acoustic waves of frequencies in the MHz range. A comprehensive study of the impact of the frequency parameters on the performance of subsurface imaging has been conducted through the use of calibrated samples and led to the validation of a numerical model for quantitative interpretation. Furthermore, this non-invasive technique has been utilized to locate lipid vesicles inside bacteria (in collaboration with Pr. A. Dazzi and M.-J. Virolle of Université Paris Sud, Orsay). Furthermore, we have combined this ultrasonic approach with infra-red microscopy, to add chemical speciation aimed at identifying the subsurface features, which represents a great advance for volume and chemical characterization of biological samples. The second technique considered is the Scanning Microwave Microscopy, which was developed in collaboration with Keysight society. Similar to acoustic-based microscopy, this non-invasive technique provided physical and chemical characterizations based on the interaction of micro-waves radiations with the matter (with frequency ranging from 0.2 and 16 GHz). Particularly, for metallic samples we performed volumetric characterization based on the skin effect of the materials. On the other hand, we have used this technique to analyze the diffusion of light chemical elements in metals and measured the effect of changes in mechanical properties of materials on their conductivity.Overall, these results constitute a new line of research involving non-destructive subsurface high resolution analysis by means of the AFM of great potential for several fields of research
37
Conti, Alfredo. "Tecniche della manifattura additiva - applicazioni in ambito aeronautico e aerospaziale." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2017. http://amslaurea.unibo.it/13306/.
Full textAbstract:
Il potenziale delle nuove tecnologie digitali applicate al settore industriale ha consentito di ridurre enormemente la durata dei cicli produttivi grazie alla rapida gestione di quantità di dati sempre più considerevoli attraverso l’introduzione delle Macchine a Controllo Numerico (Computer Numerical Control – CNC).
Nel corso delle ultime tre decadi, l’industria manifatturiera ha subito notevoli e sostanziali cambiamenti grazie ad una sempre più forte connessione con il mondo dell’informatica.
La più grande rivoluzione in tale ambito è stata segnata dall’avvento della Manifattura Additiva (Additive Manufacturing - AM), conosciuta sotto diversi nomi, tra i quali Prototipazione Rapida (Rapid Prototyping), Manifattura Rapida (Rapid Manufacturing) o Libera Fabbricazione di Forme (Free Form Fabrication).
Materia di ricerca e sviluppo sin dalla fine degli anni ’80, la Manifattura Additiva consente la creazione di elementi fisici tridimensionali partendo da modelli CAD attraverso la sovrapposizione successiva di materiale strato per strato (layer by layer), offrendo i benefici di una elevata flessibilità geometrica degli elaborati, altrimenti irraggiungibile attraverso le tradizionali tecniche di Manifattura Sottrattiva operanti per asportazione di materiale. In seguito ad intensive ricerche, progressi significativi sono stati fatti nello sviluppo e nella commercializzazione di nuovi ed innovativi processi AM.
38
Lange, Katharina. "Multidimensionale Darstellung der proximalen RCA in 3D4D- Technik im Vergleich zur Koronarangiographie." Doctoral thesis, 2013. https://ul.qucosa.de/id/qucosa%3A12643.
Full textAbstract:
Das Ziel der vorliegenden Studie war die Analyse der Detektierbarkeit von Stenosen und Lumenverschlüssen im proximalen Bereich der rechten Koronararterie mit konventioneller 2D- und 3D- Echokardiographie von transthorakal. Zusätzlich wurden die Befunde der 3D-Echoloops mit den Untersuchungsergebnissen der Koronarangiographie verglichen. Methodisch wurden daher bei Patienten mit bestehender Indikation zur Koronarangiographie vorhergehende zweidimensionale parasternale Lang- (n=91) und Kurzachsenaufnahmen (n=76), sowie parasternale dreidimensionale (n=91) echokardiographische Aufnahmen des Ostiums und der proximalen Region der rechten Herzkranzarterie durchgeführt. Durch zusätzliche Schnittebenen der proximalen Abschnitte der rechten Koronararterie sollte die konventionelle zweidimensionale Echokardiographie für eine Stenosendetektion ergänzt werden. Diese ermöglichten eine genaue Darstellung der rechtskoronaren Morphologie im proximalen Gefäßbereich. Maximal konnten die proximalen 35mm der rechten Koronararterie untersucht werden. Die Ergebnisse der einzelnen verschiedenen echokardiographischen Dokumentationen wurden miteinander und mit denen der Koronarangiographie verglichen. Insgesamt zeigten sich keine signifikanten Unterschiede zwischen den Ergebnissen der 2D Echokardiographie und der Koronarangiographie. Die Diameter der Streckenmessungen an der rechten Koronararterie in der 3D-Echokardiographie und der Koronarangiographie sind hingegen in ihren Mittelwerten signifikant verschieden. Dies ist durch häufigere Sekantenanschnitte der Gefäße mittels Echokardiographie bedingt. Die höchste Sensitivität konnte mittels 3D-Echokardiographie (98%) nachgewiesen werden, wohingegen die zweidimensionale Technik bessere Spezifitäten (91% in 2D-Langachsen- und 92% in 2D-Kurzachsen-Aufnahmen) aufweist. Diese Ergebnisse zeigen den Nutzen der Echokardiographie im klinischen Alltag zur intravasalen Stenosendetektion der rechten Koronararterie.:1 Einleitung 1
2 Material und Methoden 5
2.1 Verwendete Geräte 5
2.1.1 Speckle Tracking Analyse durch Automated Function Imaging (AFI) 6
2.2 Patienten 9
2.2.1 Echokardiographische Untersuchung 9
2.2.2 Herzkatheteruntersuchung 11
2.3 Studiendauer 12
2.4 Datenerhebung und Auswertung 13
2.4.1 Postprocessing der echokardiographischen 3D-Datensätze 14
2.5 Statistische Verfahren 16
3 Ergebnisse 18
3.1 Informationen zum Studienprotokoll 18
3.2 Längen der dokumentierten RCA 18
3.3 Durchmesser der rechten Herzkranzarterie 19
3.4 Spezifität und Sensitivität der echokardiographischen Darstellung einer rechtskoronaren Stenose oder eines Verschlusses 20
3.4.1 Sensitivität und Spezifität der RCA-Stenosen- und Verschlussdetektion mittels Echokardiographie in der 2D-Darstellung der langen Achse parasternal 22
3.4.2 Sensitivität und Spezifität der RCA-Stenosen- und Verschlussdetektion mittels Echokardiographie in der 2D-Darstellung der kurzen Achse parasternal 22
3.4.3 Sensitivität und Spezifität der RCA-Stenosen- und Verschlussdetektion mittels Echokardiographie in der 3D-Darstellung parasternal 22
3.5 Bland-Altman Plot 23
3.5.1 Minimale Diameter der 2D-Echokardiographie lange Achse im Vergleich zur Koronarangiographie 24
3.5.2 Minimale Diameter der 2D-Echokardiographie kurze Achse im Vergleich zur Koronarangiographie 26
3.5.3 Minimale Diameter der 3D-Echokardiographie im Vergleich zur Koronarangiographie 28
3.6 Normalverteilung und Mittelwertvergleich 30
3.6.1 Weite der RCA-Durchmesser der 2D- Echokardiographie lange Achse versus Koronarangiographie 30
3.6.1.1 Test auf Normalverteilung 30
3.6.1.2 Student-t-Test auf Signifikanz der Mittelwerte 31
3.6.2 Weite der RCA-Durchmesser der 2D-Echokardiographie kurze Achse versus Koronarangiographie 32
3.6.2.1 Test auf Normalverteilung 32
3.6.2.2 Student-t-Test auf Signifikanz der Mittelwerte 33
3.6.3 Werte der RCA-Durchmesser der 3D Echokardiographie versus Koronarangiographie 34
3.6.3.1 Test auf Normalverteilung 34
3.6.3.2 Student-t-Test auf Signifikanz der Mittelwerte 35
3.7 Fallbeispiele 36
3.7.1 Gesunde Studienteilnehmer 36
3.7.2 Messergebnisse: Durchmesserbestimmungen durch echokardiographische 2D- Langachsenaufnahmen versus Koronarangiographie 40
3.7.3 Messergebnisse: Durchmesserbestimmungen durch echokardiographische 2D-Kurzachsenaufnahmen versus Koronarangiographie 46
3.7.4 Messergebnisse: Durchmesserbestimmungen durch echokardiographische 3D-Aufnahmen versus Koronarangiographie 49
3.7.4.1 Drei Patientenbeispiele mit detektiertem RCA-Verschluss 50
3.8 Patientenbeispiele mit möglichen Fehlerquellen der Befundinterpretation (Bedeutung einer sorgfältigen retrospektiven Analyse) 60
4 Diskussion 69
5 Zusammenfassung 76
6 Literaturverzeichnis 79
7 Anhang 83
7.1 Erklärung über die eigenständige Abfassung der Arbeit 83
7.2 Lebenslauf 84
7.3 Danksagung 86
39
Stephens, David. "3D1D modeling of the convective-reactive mixing in rapidly accreting white dwarfs." Thesis, 2019. http://hdl.handle.net/1828/11414.
Full textAbstract:
1D stellar evolution and nucleosynthesis simulations have traditionally modeled the mixing within convection zones as a diffusive process. The fluids within a convection zone are advecting and do not diffuse. However the diffusive approximation is valid when the burning timescale of an exothermic reaction is longer than the convective turn over timescale to which the mixing of those species is approximated over. Since it is 1D, it also assumes that the material is isotropically distributed within the convection zone. In the He-flash convection zones of rapidly accreting white dwarfs (RAWD) H is ingested and burned well within the convective turn over time of 38 minutes. The H is burned through the exothermic 12C(p,γ)13N reac- tion, Q = 1.944 MeV, and then the unstable 13N, with a half-life of 9.6 minutes, will decay to 13C which will undergo the 13C(α,n)16O reaction releasing neutrons. The neutron densities, depending on the H-ingestion rates and mixing details, reach Nn ≈ 1013 − 1015 cm−3 which starts the i-process within the convection zone. The H burning provides energy to the flow leading to the dynamic details of the flow being important for the mixing of the H and thus the i-process nucleosynthesis. This is a convective-reactive environment. The isotropic, well mixed over many convective turn over timescales, and long burning timescale assumptions for H in the diffusive approximation are broken in the convective-reactive environment of a He-shell flash convection zone in a RAWD.
To more accurately model convective-reactive mixing environments, a 1D two stream advective mixing model is formulated. A downstream advects H-rich material from the top of the convection zone down to the H-burning region while the upstream advects H-poor material back up to the upper convective boundary. The mixing model includes a horizontal mass flux, γ, which describes the efficiency to which mass is mixed between the two streams. This predominately causes the homogenization of the material between the two streams. The radial mass flux, α, and the horizontal mass flux, γ, are calibrated from 3D hydrodynamic simulations of the RAWD in order to model the mixing within the He-flash shell convection zone.
The downsampled 3D cartesian data output, the briquette data, from the 3D hy- drodynamic simulations is used to compute γ. This required using numerical tools to interpolate quantities onto spherical shells from 3D cartesian data and to decompose the radial velocity field into its spherical harmonic modes. Trilinear interpolation is the simplest 3D interpolation method that was tested and it was the interpolation method of choice due to the constraints it has on the interpolating function. The validity of using higher order methods on the briquette data was studied in detail but was determined to not be usable due to the computational effort and constraints of the methods.
The two stream model post-processing of the H burning within the 3D hydro- dynamic simulations of the RAWD showed excellent agreement in the metrics of the total mass of H burned, the burning rate and burning location of H. This includes two models which undergo dramatic H-ingestion and burning events caused by a GOSH, Global Oscillations of Shell H-ingestion. By adding a network containing 1000’s of species to the 1D advective mixing model, the i-process from the RAWD is simulated and compared with a traditional 1D diffusive mixing model. The resulting neutron densities between the two models are comparable however the efficiency to which each produce the heaviest stable elements are different. To reproduce the elemental abun- dance distribution of the CEMP-r/s star CS31062-050, the diffusive model is run for 15 days of stellar time while the advective model is run for 20 days. The H-ingestion into the He-shell as predicted by the stellar evolution calculations lasts 30 days. The i-process material within the RAWD can be removed from it and participate in the galactic chemical evolution of the galaxy that it resides in. This is due to the RAWD possibly reaching the Chandrasekhar mass and from the loss of material through stellar winds and common envelope interactions with its nearby companion star.Graduate
40
Chang, Wei-Ting, and 張維庭. "Control of Curing Depth in Visible Light 3DP Resin." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/gm976s.
Full text
41
Jhong-WunYe and 葉仲文. "Baseline Elimination by Wavelet and Cubic-Spline Interpolation for 3DPM and Improvement of L-Cube Pulse Mapping Recognition." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/41406001380622067362.
Full textAbstract:
碩士國立成功大學
電機工程學系
104
This research proposed a pulse wave processing framework of baseline removal based on wavelet and cubic-spline interpolation. With the consideration of subject movement, sensor hardness and other situations, the framework processes pulse signal in each channel adaptively for good construction of the 3DPM. The result shows that the proposed framework has good performance for pulse wave signals with different qualities. However, the high-frequency suppression of this work can be improved on future research. This study has modified the L-Cube recognition proposed previously and improved the methods of fitting and evaluation. Hyperplanes in both x- and y-direction are added into the L-Cube function for a better flexibility when describing an asymmetric 3DPM. Also, the shape parameter a and b are replaced with the axis ratio r and the decay parameter σ. As the fitting process completes, the axis ratio is found to be the new string-like index which is more sensitive than the eccentricity ε. However, the new L-Cube is still not able to describe non-uniform 3DPMs well and further research can be done on this. On the topic of fitting method and evaluation, we abandon the volume error (VE) and R2 but keep the root mean squared error (RMSE). Besides, the weighted RMSE, rotation angle error and the center point deviation are introduced for the fitting and its evaluation. From the experiment, we have found the weights of above terms are suggested to be 1 : 1 : 0.01 : 0. Using the weights concluded above, a cold pressor data (CPT) was analyzed with the new L-Cube function. The resultant string-like index increased as the cold stimulation applied and went back down as the of ice bag removed. This verified the work related to making blood pressure higher temporally by CPT so that the pulse condition tends to get more string-like as well. Besides, the variation of r indicates the individual differences may lead the pulse condition fail to get more string-like through the CPT.
42
Beckert, Barbara. "A post-frontier in transformation: land relations between access, exclusion and resistance in Jambi province, Indonesia." Doctoral thesis, 2017. http://hdl.handle.net/11858/00-1735-0000-0023-3DBD-F.
Full text
43
Hoffmann, Lisa Barbara. "Übertragungen von Keimen auf einer speziellen, vorwiegend nicht-invasiven Beatmungsintensivstation." Doctoral thesis, 2017. http://hdl.handle.net/11858/00-1735-0000-0023-3DDD-7.
Full text
44
Nühnen, Viktoria Patrizia. "Der Einfluss von vertikaler Ganzkörpervibration in Kombination mit Strontiumranelat und Teriparatid auf die metaphysäre Frakturheilung der osteopenen Rattentibia." Doctoral thesis, 2017. http://hdl.handle.net/11858/00-1735-0000-0023-3DED-3.
Full text
45
Krüger, Jennifer-Rose. "Tomographic STED Microscopy." Doctoral thesis, 2017. http://hdl.handle.net/11858/00-1735-0000-0023-3DCD-B.
Full text
46
Ding-YuChen and 陳鼎煜. "Finite Element Analysis of the Interface Pressures between Stump and Transtibial Socket Manufactured by CAD/3DP Process." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/53051976676204820518.
Full textAbstract:
碩士國立成功大學
機械工程學系
103
Most transtibial sockets are made by prosthetist with traditional manual process. However, the process includes lots of complicated modification skills which directly affect the quality of transtibial sockets. Moreover, a certificated prosthetist also need plenty of experience and cases. To solve these problems, our laboratory has developed a CAD/3DP transtibial socket model manufacturing process, which uses the philosophy of reverse engineering. The research developed a finite element (FE) model to predict the interface pressures between transtibial stump and the CAD/3DP socket during walking. The boundary conditions of the knee joint were measured using Motion Analysis System and a force plate in the gait laboratory. Ultimately, the FE-predicted results were compared with interface pressures of experimental measurement. The FE-predicted results showed that the average pressure of peak 1 and peak 2 at patellar tendon, tibia end and fibular end sites was 12.2% higher than that measured from Tekscan System. In addition, the pressures patterns of FE-predicted results and measurement results were similar at patellar tendon, tibia end and fibular end sites.
47
Landeman, Philip. "Samband mellan geologiska och bergmekaniska egenskaper i bergmaterial som bärlager till riksväg 51 : Riksväg 51 sträckan Svennevad - Kvarntorpskorset." Thesis, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-80189.
Full textAbstract:
This thesis was created to ensure the quality of the rock which would be crushed to base layer construction material, in a road cut at Swedish highway 51, and to find a possible link between the rock's abrasion resistance and its mineralogy. Rock samples were collected, and among other things, several ball mill tests were carried out. The design of the road project was carried out by Loxia Group AB with NCC Group as contractor.A total of 18 rock samples and 2 base layer samples were taken in the area and they were all tested in a ball mill. The results showed that of the 18 rock samples, 2 samples had a ball mill value of less than 16 on the scale, 10 samples had values from 16 to 20, in addition to this, 3 samples had values from 20 to 21 and 3 samples had values in excess of 21 on the Swedish ball mill scale.Of the 3 samples with a ball mill value higher than 21, all contained a larger amount of biotite. Biotite did not appear to the same extent among the samples that ended up further down the ball mill scale. This link was so clear that a conclusion was subsequently drawn from this. The samples taken on the prefabricated base layer both had a ball mill value between 16 and 20. Overall, both the base layer and the rock material passed the Swedish Government’s Transport Administration’s requirements according to "TRVKB 10, Obundna lager". The rock type that was on the south part of the rock cut, adjacent to a deformation zone, had way too poor quality to undergo a ball mill test and therefore there are no values taken from that area.The conclusion of the work is that the rock material overall meets the Swedish Government’s Transport Administration’s requirements for base layer construction materials according to "TRVKB 10 Obundna lager", that a clear link between the proportion of biotite in a rock material and its abrasion resistance exists, and that the broken rock in the south should not be used as construction materials since the rock has insufficient mechanic capacity.