<p>Two longstanding goals in subsurface science are to induce fractures with a desired geometry to adaptively control the interstitial geometry of existing fractures in response to changing subsurface conditions. Many energy and water-related engineering applications that use induced fractures to withdraw and inject fluids from subsurface reservoirs occur in some sedimentary rock.  Sedimentary rock such as shales often exhibit anisotropic mechanical properties because of bedding, layering and mineral texture.  These structural and textural features also affect fracture formation and in turn the resulting fracture geometry. Understanding the interplay between the microscopic mineral fabric and structure and how it effects fracture geometry is important for the prediction of the geometry of induced fractures and to the determination of the most ideal conditions for maximizing energy production and minimizing leaks from sequestration sites in the subsurface. </p> <p><br></p> <p>This Ph.D. thesis research focuses on the formation and geometry of fractures in anisotropic rock and the identification of geophysical signatures of fracture formation using additively manufactured gypsum rock analogs. Specifically, the work is grouped into three topics: (1) material controls on fracture geometry, toughness and roughness in additively manufactured rocks; (2) acoustic emissions (AE) during fracture formation in anisotropic additively manufactured rocks; and (3) determination of the effect of fluid-filled oriented voids in fractures on compressional to shear wave conversions. </p> <p><br></p> <p>For topic (1), unconfined compressive strength (UCS), Brazilian and 3-point bending (3PB) tests under pure and mixed mode mechanical tests were performed on cast and 3D printed gypsum samples that were characterized using 3D Xray microscopy, Xray Diffraction and SEM to examine the micro-structure of the samples. Research on topic 1 discovered microstructural controls on fracture surface roughness and the failure behavior of anisotropic rock and that the failure mode (tensile, mixed mode I and II, mixed mode I and III) affects the fracture propagation path and the surface roughness which is controls to the flow paths through a fracture. The results suggest that detailed mineralogical studies of mineral texture/fabric in laboratory or core samples is important to unravel failure strength, surface roughness, and how fractures propagate in layered geological media. </p> <p><br></p> <p>For topic (2), UCS tests were performed with concurrent measurements of acoustic emissions (AE) on cylindrical specimens: cast gypsum (CG) samples, and 3D printed (3DP) samples with five different orientations of bassanite layer and gypsum texture relative to the loading direction. Mechanical properties and induced fracture surface information were compared with the collected the AE signals to study if there is a way to tell the differences between the induced fracture surfaces with the AE signals patterns together with loading data. Examination of the AE signal amplitude from post-peak loading revealed that more ductile behavior was associated with more AE events that occurred over a longer period of time, and the resultant fracture surfaces were rougher than for narrow time distributions of events. </p> <p><br></p> <p>For topic (3), a detail study of fracture void orientation was performed using ultrasonic compressional, P, and shear, S, waves to determine how energy is partitioned when P-to-S or S-to-P conversions occur for waves normally incident on an air-filled or fluid-filled fracture. In this study, experiments and computer simulations were performed to demonstrate the link among cross-coupling stiffness, micro-crack orientation and energy partitioning into P, S, and P-S/S-P wave. The cross-coupling stiffness was created by 3D printing samples with linear arrays of micro-cracks oriented at  $0^o$, $\pm15^o$, $\pm30^o$, $\pm45^o$, $\pm60^o$, $\pm75^o$, and $90^o$. For $45^o$ orientation, measurements were made on air-filled and fluid-filled (silicon oil). For the air-filled fractures, the observed energy partitioning matched the simulated behavior obtained from discontinuous Galerkin simulations. Information on local fracture geometry is contained in the far-field waves. When filled with a viscous fluid, the P- and S- waves amplitude exhibited slight increases and decreases, respectively. The P-to-S converted mode amplitude decreased 30\% with an increase in fluid viscosity from 1–300kcSt. This suggests that P-S converted mode provides a potential method to remotely probe changes in fluid viscosity in fractures. </p> <p><br></p> <p>The work from the 3 research topics demonstrated that micro-scale structure impacts macroscale behavior and signals used for monitoring the condition of a rock. Additively manufactured samples enabled the exploration and determination of (1) the impact of mineral fabric orientation in layered media on failure load, fracture propagation path, and fracture surface roughness, (2) the sensitivity of P-to-S conversions to fluid viscosity, and (3) how oriented voids within a fracture effect energy partitioning. These research findings advances our current understanding of role microscopic properties and structure on the generation, propagation and geometry of induced fractures in anisotropic rock, and help to identify the best imaging modalities to use to identify the seismic signatures of the viscosity of fluids in fractures with oriented voids. These contributions will help unravel the complex behavior often observed in natural rock that is structurally and compositionally complex with features and heterogeneity.  </p> <p><br></p>

Vocal fold models are valuable for studying voice production. They provide an alternative method of studying the mechanics of the voice that does not require in vivo experimentation or the use of excised human or animal tissue. In this thesis, a new method of creating vocal fold models through additive manufacturing is described. The purpose of this research was to reduce model fabrication time, to decrease the number of model failures during manufacturing, and to lay the foundation for creating models with more lifelike geometric and material properties. This research was conducted in four stages. First, a suitable silicone additive manufacturing technique using a UV-curable silicone was chosen. The technique chosen was called freeform reversible embedding (FRE) and involved embedding liquid silicone material into a gel-like medium named organogel. The UV-curable silicone's material properties were identified to confirm its utility in vocal fold model design. Second, an open-source, fused deposition modeling slicing software was selected to create g-code for the printer. Applicable software settings were tuned through qualitative printing tests to find their optimal values for use in FRE printing. Third, 3D-printed cubes were used in tensile tests to characterize the material properties of FRE-printed, silicone material. The cubes were found to be anisotropic, exhibiting different modulus values corresponding to the layer orientation of the printed material. Fourth, vocal fold models were FRE-printed in two different layer orientations and were used in phonation tests to gather data for onset pressure, vibratory frequency, amplitude, and flow rate. The printed models self-oscillated and withstood the strains induced by phonation. These tests showed that layer direction affects the phonation properties of the models, demonstrating that models with layers in the coronal plane had slightly lower frequencies and onset pressures than models with layers in the sagittal plane. The models' onset pressures were higher than what is found in human vocal folds. However, their frequencies were within a comparable range. These tests showed the effectiveness of additive manufacturing in the application of vocal fold fabrication, reducing production effort by allowing researchers to go directly from model design to fabrication in a single manufacturing step. It is anticipated that this method will be modified to incorporate printing of multiple stiffnesses of silicone to better mimic the material properties of vocal fold tissue, and that the anisotropy of 3D-printed material will be leveraged to model the anisotropy of human vocal folds. This work also has potential application areas outside of voice research.

I det här examensarbetet undersöks möjligheterna med framtida storskaliga 3D-skrivare i byggindustrin. Mycket händer just nu på området och vi är på väg mot en ny revolution i byggnadskonsten där robotarna och 3D-skrivarna kommer att ha en allt mer betydande roll. Arbetet undersöker i detalj hur vi skulle kunna använda oss av tekniken. En villa har fått stå modell för olika typer av experiment och redovisar olika tankar och idéer kring ämnet. / This Master Thesis project examines the opportunities with future large scale 3D-printing in the construction industry. A lot is happening with new 3D-printers and materials and we are on our way towards a revolution in the art of construction. A future world where the robots and 3D-printers will play a big role. The project examines in detail how we can use this new technique. A villa have been a model for different types of experiments and shows different thoughts and ideas around the subject.

No description available.

Indiana University-Purdue University Indianapolis (IUPUI) / Introduction: Endodontic treatment in teeth with pulp canal obliteration (PCO) is challenging. Guided Endodontic Access (GEA) combines information from a cone-beam computed tomography (CBCT) scan with an intra-oral scan to create a stent that can be used as a guide to treat teeth with PCO. GEA stents designed with traditional palatal accesses were shown to be successful in accurately negotiating these 3D printed teeth with simulated PCO, however, the difference in accuracy between the traditional palatal access compared to a conservative incisal access is not yet known. Objective: This in vitro study compares GEA stents designed with an incisal access approach to GEA stents designed with a traditional palatal access approach. The effect on the overall degree of deviation of the designed access path from the prepared path is evaluated by measuring the degree of angle of deviation and amount of deviation in millimeters. Materials and Methods: A 3-D printed maxillary model of an anonymous patient was used. PCO was simulated in a 3D printed natural #8 using the coDiagnostiX software tooth at two levels: coronal and mid-root. A GEA stent that extended from tooth #3 to tooth #14 with a guide sleeve over the simulated tooth #8 was accessed with a dedicated 1.0 mm diameter and 20 mm length drill that is designed to fit the access sleeve. 15 GEA stents had guides utilized for the incisal access approach, and 15 GEA stents had guides utilized for the traditional palatal access approach. Results: Angle, mesio-distal (base), and mesio-distal (tip) deviations were significantly lower for the incisal access compared to the traditional access. Inciso-apical (base) deviation was significantly more negative for incisal access compared to the traditional access. Bucco-lingual (base) deviation was significantly more negative for traditional access compared to the incisal access, while incisal and traditional accesses were not significantly different for bucco-lingual (tip) deviation. Coronal 1/3 calcification groups had significantly more mesio-distal (base) deviation than the middle 1/3 and no PCO groups. The no PCO group had significantly more negative inciso--apical (base) deviation than the coronal 1/3 calcification and middle 1/3 calcification groups, and the coronal 1/3 calcification group was significantly more negative than the middle 1/3 calcification group. The coronal 1/3 calcification group had significantly more mesio-distal (tip) deviation than the no PCO group. PCO level did not have a significant effect on angle, bucco-lingual (base), or bucco-lingual (tip) deviations. Conclusion: The utilization GEA via incisal access resulted in less degree and amount of drill deviation compared to the traditional access at all levels of calcification, however, the level of PCO did not influence the degree and amount of drill deviation between the incisal and traditional access approaches. It can be concluded that the use of a GEA stent that utilizes an incisal access approach in teeth with PCO will result in a more predictable outcome.

With the rapid increase in utilization of the cheap and user friendly Fused Filament Fabrication, FFF 3D printer, a deeper knowledge about the technique is needful. The frame restricting the 3D printers for prototyping purposes is fading and a new phase of endless application possibilities is emerging. To bridge the gap in possible applications from prototypes to real products it is key to know and improve the factors affecting durability. With over a hundred settings and parameters to tweak the FFF 3D printing process there are a lot of opportunities, opportunities to optimize for durability.The tensile properties of some of the most used FFF 3D printing materials together with a few nylon based materials are examined, which are popular in engineering applications. The materials tested are ranging from rigid to flexible, rubber like materials. The most common failure scenario of a FFF 3D printed product is layer bonding failure. The factors affecting layer bonding performance are studied.The measurements are carried out using tensile testing equipment at Blekinge Institute of Technology. All tested specimens are manufactured at Creative Tools AB Halmstad with the FFF 3D printers Flashforge Dreamer and Makerbot Replicator 2X.The tensile strength of 3D printed PLA is found to be 51 MPa. PET has a tensile strength of 40 MPa and ABS 34 MPa. Stress-strain behavior of the materials shows that ABS is slightly softer than PLA and PET are slightly softer than ABS. PLA being the hardest material in the test. ISO 527-2 tensile testing standard is used but the tests diverge from the standard in several ways. The measurement data presented in this study can be very useful to guide the design engineer to choose the most durable plastic for the unique application.Five basic 3D printing settings are evaluated for layer bonding performance, by measuring the load capacity of a PLA specimen loaded transversally relative to the layers. Four of the settings show to possibly affect the layer bond’s load capacity by 50 % or more individually.The results of this study are presented in graphs, diagrams and pictures. These may help the 3D printer user to tweak basic settings to increase layer bonding performance and ultimately the durability of the product significantly.

Proton therapy, a relatively young modality in radiation therapy, has proven useful in cases where a sharp dose gradient or low secondary irradiation is required. In Canada proton therapy it was performed at the TRIUMF Proton Therapy Facility in the treatment of large or difficultly positioned ocular melanomas. This rare primary malignant cancer of the eye has a poor prognosis if untreated. Patient vision sparing is critical for quality of life and is strongly affected by the accuracy of the chosen treatment. Reduction in irradiation of critical structures is a proven strength of proton therapy due to the high dose-gradient and finite range in tissue. But, with the advantage of steep dose gradients, comes the requirement of precision target positioning and planning. Monte Carlo particle transport software is a valuable tool for understanding treat- ment doses in cases where measurement is time consuming or difficult. Accurate simulation of primary proton dose to water aids in the evaluation of beam charac- teristics and allows for study into improving dose application for patient treatment. In this work, a full Monte Carlo model of the TRIUMF proton therapy facility was developed. Measurements were taken in water to validate simulated results within 2% over the treatment depth for a wide range of beam modulations. The second advantage of proton therapy lies in its reduced dose bath to healthy tissue. This is especially important in pediatric cases where extraneous dose comes with a high risk of secondary carcinogenesis. Whereas multi-angle photon treatments necessarily irradiate large volumes of healthy tissue to produce a flat target dose, proton treatments may irradiate a target with a single beam. With this advantage comes a trade-off - protons produce a large number of neutrons as they are prepared for patient treatment. These neutrons are the largest contributor to secondary dose in proton therapy and must be well modeled and shielded to ensure patient safety. The second part of this work involves the measurement of secondary neutron doses in the TRIUMF treatment room. Measurements were validated within 20% of simulated values with uncertainties dominated by calibration of the detector. Neutron doses to an anatomic human model showed that calibrated secondary doses were in line with similar treatment facilities reporting globally. Simulations indicated that the source of neutrons was primarily in the unshieldable region of the beamline opening. Thus the total treatment time was the determining factor in secondary dose to the patient. With primary proton dose well modeled, it became possible to study the pre- cision of treatment and possible avenues for improvement. The beam modulation wheels and optimization scheme was developed in the late 90‘s when computational and manufacturing technologies were less developed. Updated optimization methods indicated that moving to a smooth scheme of energy modulation, as opposed to a stepped modulation wheel, could improve distal dose sharpness. This was contrary to the long-held belief that there was an optimal number of steps for modulation. The third portion of this work explored the use of 3D printers to enable the fabri- cation of smoothly transitioning modulator wheels. Materials and printer methods were studied, indicating a strong candidate in the PolyJet TM method for beam mod- ulation. Both stepped and newly-optimized smooth modulator wheels were printed and validated. Total turnaround time for modulator production was under 24 hours - proving the feasibility of patient-specific beam modulation. The last portion of this work explored the use of positron emitting isotopes for dose validation. Protons traversing tissue or plastic generate β + emitting isotopes via nuclear interactions. The resulting back-to-back annihilation photons can be re- constructed into the isotope distribution produced by the beam. This can potentially provide information about beam position in the target and hence position of a phan- tom or patient. An anatomic 3D printed eye phantom was designed and irradiated to test the feasibility of this method. While a strong isotope signal was reconstructed, the test did not yield a viable technique due to the low resolution of the phantom scan. The phantom position was poorly reconstructed using the transmission scan. Despite this, it could be possible to improve this method by using other methods for phantom position registration. / Graduate

Since the late 20th century, breakthroughs in technology have been occurring expeditiously. Indeed, technological innovations have provided the betterment of many aspects of life and ensured humans’ appropriate forms of evolution and civilization. It is safe to claim that medicine has advanced within the past few decades, especially with the upbringing of technological innovations. The world of medicine would not have experienced its recent breakthroughs and profound discoveries without utilizing the available technology. The improvements observed in medicine and technology resulted in better providing of healthcare. Customizing treatments for each patient is now possible. One method of applying customization is through 3D printing of materials such as artificial prosthetics, tissues, and organs. This literature review analyzes 3D printing by stating definitions, assessing its history, discussing its different applications and closing with evaluating future directions. 3D printing first appeared in the late 20th century, and its primary purpose was to design and manufacture products efficiently and accurately. Traditional production of structures involves subtractive manufacturing (carving, cutting, and other methods of reshaping materials) to achieve desired products, whereas 3D printers implement additive manufacturing (a layer-by-layer approach). This provides less time, greater accuracy, and labor-free fabrication of products. Computerized software is one of the essential parts of 3D printing, and functions include designing, scaling, visualizing, controlling production frequency, and many more. In medical applications, the software may require CT scans, cone beam computed tomography, and intraoral scanners (for dental applications). The 3D printing techniques identified in this review are generally applied in oral and maxillofacial procedures—stereolithography, which constructs a product layer-by-layer through curing liquid resin using a UV laser. Digital light projection is a method similar to stereolithography, with a few differences, such as using a UV light instead of a laser and using a liquid crystal display panel. Fused deposition modeling is a technique that melts plastic filaments and extrudes them through a nozzle to form a structure in a layer-by-layer fashion. Selective laser sintering is also similar to stereolithography, where it uses a laser to form an object layer by layer, but the material is a thin layer of plastic powder instead of liquid resin. The power binder printing technique applies droplets onto powdered materials, adhering and forming layers as designed via computerized software. Lastly, computed axial lithography is similar to digital light projection, except the light is projected from many angles at once instead of one layer at a time. The main objectives of this literature review are to investigate each technique, discuss the advantages and disadvantages, and list the commonly applied areas in medicine for each. Also, this review evaluates the current limitations experienced when using 3D printers and suggestions for overcoming them. Some limitations include, but are not limited to, excessive time allocated for producing specific structures, accurate capturing of surgical sites, use of appropriate materials that form printed structures, cost, and deficiencies of reported data. Lastly, this literature review assesses the future projections. The future holds promising breakthroughs in 3D printing technology, including the fabrication of dental stem cells, operating artificial organs, complex vascular tissues, customized artificial alveolar structures for oral and intracranial procedures, and regeneration of periodontal tissues. These projections may occur by overcoming the most reported limitations. Medicine is digitizing rapidly and will continue adapting to the latest technological inventions. The current efforts to advance 3D printing technology will likely positively impact the advancement of many fields, including healthcare, increase chances of positive postoperative outcomes, and potentially combat many health issues society faces today. Professionals across disciplines must come together to further research and educate curriculums to revolve around the innovative technologies to continuing education courses related to 3-D printing technologies.

The focus of this thesis is on the transition from 2D character design to 3D model design, and how this transition affects the appeal, fluidity, and clarity of the 2D design. The source material for this project was an original screenplay entitled The Birds Work for Bea. Three characters from the material were selected for a process including ideation, research, 2D character and style exploration, 3D sculpting, and 3D printing and finishing. This project serves as a study in all aspects of the character concept development pipeline.

Additive manufacturing (AM), also called 3-dimensional printing (3DP), emerged as a disruptive technology affecting multiple organizations' business models and supply chains and endangering incumbents' financial health, or even rendering them obsolete. The world market for products created by AM has increased more than 25% year over year. Using Christensen's theory of disruptive innovation as a conceptual framework, the purpose of this multiple case study was to explore the successful strategies that 4 individual managers, 1 at each of 4 different light and high-tech manufacturing companies in the Netherlands, used to adopt AM technology into their business models. Participant firms originated from 3 provinces and included a value-added logistics service provider and 3 machine shops serving various industries, including the automotive and medical sectors. Data were collected through semistructured interviews, member checking, and analysis of company documents that provided information about the adoption of 3DP into business models. Using Yin's 5-step data analysis approach, data were compiled, disassembled, reassembled, interpreted, and concluded until 3 major themes emerged: identify business opportunities for AM technology, experiment with AM technology, and embed AM technology. Because of the design freedom the use of AM enables, in combination with its environmental efficiency, the implications for positive social change include possibilities for increasing local employment, improving the environment, and enhancing healthcare for the prosperity of local and global citizens by providing potential solutions that managers could use to deploy AM technology.