This study sought to determine how five neighbourhood models (the Grid, Loop and Cul-de-Sac, Fused Grid, New Urbanist and Greenway) compare in terms of the characteristics known to affect active transportation rates, and which model is most likely to be able to facilitate active transportation as a result. In order to do so, model principles and design characteristics of case study neighbourhoods were described and used to create a range of design specifications for each model. These specifications were then used to develop a GIS-based representation of an example neighbourhood for each model, which included the transportation network, parcels of different land use types and densities, homes and destinations. GIS, statistical and graph-based techniques were then used to comprehensively assess and compare the models in terms of their potential to facilitate walking and biking through the built environment correlates identified in through a literature review. The models were ranked on each variable, and then an overall comparison was made on the basis diversity (land use mix), density and design - the three dimensions identified by Cervero and Kockelman (1997) as being the key ways through which the built environment can contribute to creating walkable (and potentially bikeable) neighbourhoods. Additional measures related to trip characteristics and issues of importance to developers (such as buildable area) were also included. The results illustrate how each model’s unique approach to facilitating walking and/or biking is reflected in the built environment characteristics assessed. While a model that was strong in one category was often weaker in another (a finding which echoes that of Filion and Hammond, 2003), the three alternative models (Fused Grid, New Urbanist and Greenway) consistently fared better than the more traditional Grid and Loop and Cul-de-Sac designs, with the New Urbanist scoring the highest on the overall evaluation of walkability and bikeability and the Greenway the best on network design for cyclists. In addition to these findings, the study also provided an opportunity to explore several challenges related to model assessment, such as issues arising from frame choice, off-set networks, and the use of roads as proxies for active transportation networks.

Gold catalysis has become an important tool to achieve highly chemoselective p-acid activation. Exceptional reactivity and selectivity are often encountered under mild reaction conditions. These properties have made gold(I) complexes suitable catalysts for tremendous applications in the total synthesis of natural products. The first chapter will highlight a number of total syntheses using gold catalysis as a key step. The second chapter will cover our application of the gold(I)-catalyzed 6-endo-dig carbocyclization for the synthesis of bridgehead-substituted scaffolds and its use toward the synthesis of PPAP natural products. This research has opened our eyes to the utility of biphenylphosphine ligands, particularly JohnPhos, in gold(I)-catalysis. The reactivity and selectivity exhibited by gold(I) complexes is modulated by the nature of the ancillary ligand. Recent research rationalizes the impact of these ligands on the divergent reactivity observed between cationic and carbenoid intermediates. Our desire to favor the 6-endo-dig pathway has led us toward the discovery of another example of the diagonal reactivity that NHC carbene and biphenylphosphine ligands can bring to gold(I)-catalysis. Chapter three will explain the development of a selective gold-catalyzed synthesis of fused carbocycles . Our selective divergent synthesis of fused carbocycles, combined with the Diels–Alder reaction, has brought new synthetic opportunities. Chapter four will describe our approach toward the synthesis of various polycyclic diterpene-related frameworks. Starting with a unique linear precursor, we have developed a new “one-pot” process for the synthesis of three different polycyclic compounds related to the terpenoid family. The facile modulation of the linear precursor and the use of different dienophiles during the Diels–Alder reaction could enable the synthesis of diverse polycyclic analogues based on three principal frameworks. The gold(I)-catalyzed synthesis of fused carbocycles reached some limitations during our study. Regioselective control was found to be substantially more challenging, with terminal alkynes or alkynes bearing a sterically and electronically neutral methyl substituent. In chapter five, we will discuss how the complementarity of silver(I) catalysis to gold(I) catalysis enabled the selective divergent synthesis of three different fused carbocycles from a unique precursor. Moreover, copper(I) catalysis has given access to the 6-endo-dig pathway on terminal alkynes without the formation of a vinylidene intermediate.

Square open loop resonator (SOLR) bandpass filters fabricated with additive manufacturing techniques are presented and studied. One filter contains novel 3D capacitive plates used to enhance resonator coupling. The filters are centered at 2.45 GHz and loaded with capacitors for miniaturization as low as 21% that of a conventional SOLR bandpass filter. The pass-band insertion loss of the filters ranges from 3.8 dB to 5.5 dB and the 3 dB bandwidth ranges from 180 MHz to 250 MHz. Also, degradation in the effective conductivity of printed ink as a function of substrate roughness is analyzed. Finally, a study of dielectric and metallic 3D printing processes that are candidates for digital manufacturing of integrated mobile phone client antennas is presented.

abstract: Material extrusion based rapid prototyping systems have been used to produceprototypes for several years. They have been quite important in the additive manufacturing field, and have gained popularity in research, development and manufacturing in a wide field of applications. There has been a lot of interest in using these technologies to produce end use parts, and Fused Deposition Modeling (FDM) has gained traction in leading the transition of rapid prototyping technologies to rapid manufacturing. But parts built with the FDM process exhibit property anisotropy. Many studies have been conducted into process optimization, material properties and even post processing of parts, but were unable to solve the strength anisotropy issue. To address this, an optical heating system has been proposed to achieve localized heating of the pre- deposition surface prior to material deposition over the heated region. This occurs in situ within the build process, and aims to increase the interface temperature to above glass transition (Tg), to trigger an increase in polymer chain diffusion, and in extension, increase the strength of the part. An increase in flexural strength by 95% at the layer interface has been observed when the optical heating method was implemented, thereby improving property isotropy of the FDM part. This approach can be designed to perform real time control of inter-filament and interlayer temperatures across the build volume of a part, and can be tuned to achieve required mechanical properties. / Dissertation/Thesis / Masters Thesis Mechanical Engineering 2016

The aim of this study was to verify the behavior of five brands of NiCr alloys, indicated to porcelain fused to metal restorations, comparing the castability with the ability of reproducing the thin edges of restoration margins. The samples were divided in five groups, each one for one brand, with ten repetitions for castability test and ten for edge reproduction, in a total of 100 specimens. A carbon free phosphate bonded investment was used for all casting procedures. Optical microscopy was used to investigate the microstructure of the specimens obtained with two of the alloys, those which have shown better results. Statistical analysis stated that the commercial brand Tilite showed both better castability and edge reproduction. / O objetivo desta pesquisa foi verificar o desempenho de cinco ligas de níquel-cromo para restaurações de metalocerâmicas, comparando a fluidez com a capacidade de cópia da borda fina das restaurações. Os corpos-de-prova foram divididos em 5 grupos um para cada liga, sendo realizado dez corpos-de-prova para o teste de fluidez e dez corpos-de-prova para o teste da cópia da borda, totalizando 100 corpos-de-prova. Um revestimento de fosfato sem carbono foi usado para todas as inclusões e fundições. Em seguida foram submetidos a microscopia óptica, para se observar a microestrutura das duas ligas que obtiveram os melhores desempenhos. Os resultados, após análise estatística, demonstraram que a liga Tilite apresentou a melhor fluidez e melhor cópia da borda.

The need for reliable and cost-effective testing procedures for Additive Manufacturing (AM) is growing. In this Dissertation, the development of a new computational-experimental method based on the realization of specific testing artifacts to address this need is presented. This research is focused on one of the widely utilized AM technologies, Fused Deposition Modeling (FDM), and can be extended to other AM technologies as well. In this method, testing artifacts are designed with simplified boundary conditions and computational domains that minimize uncertainties in the analyses. Testing artifacts are a combination of thin and thick cantilever structures, which allow measurement of natural frequencies, mode shapes, and dimensions as well as distortions and deformations. We apply Optical Non-Destructive Testing (ONDT) together with computational methods on the testing artifacts to predict their natural frequencies, thermal flow, mechanical properties, and distortions as a function of 3D printing parameters. The complementary application of experiments and simulations on 3D printed testing artifacts allows us to systematically investigate the density, porosity, moduli of elasticity, and Poisson’s ratios for both isotropic and orthotropic material properties to better understand relationships between these characteristics and the selected printing parameters. The method can also be adapted for distortions and residual stresses analyses. We optimally collect data using a design of experiments technique that is based on regression models, which yields statistically significant data with a reduced number of iterations. Analyses of variance of these data highlight the complexity and multifaceted effects of different process parameters and their influences on 3D printed part performance. We learned that the layer thickness is the most significant parameter that drives both density and elastic moduli. We also observed and defined the interactions among density, elastic moduli, and Poisson’s ratios with printing speed, extruder temperature, fan speed, bed temperature, and layer thickness quantitatively. This Dissertation also shows that by effectively combining ONDT and computational methods, it is possible to achieve greater understanding of the multiphysics that governs FDM. Such understanding can be used to estimate the physical and mechanical properties of 3D printed components, deliver part with improved quality, and minimize distortions and/or residual stresses to help realize functional components.

No description available.

The Master's thesis deals with the determination of mechanical properties of materials used for 3D printing by ALPS ELECTRIC CZECH, s.r.o. (PETG, PLA, ABS, PLA ESD), extended of new materials (ASA, PC / ABS). The prepared test samples, produced by 3D printing technology Fused Deposition Modeling, were analyzed using mechanical tests (tensile test and two hardness tests), surface roughness and dimensional accuracy. Statistical evaluation was performed for individual materials of selected parameters (tensile strength, modulus of elasticity in tension, elongation, Shore hardness, hardness of ball indentation). The conclusion of the thesis is devoted to the comparison of materials by selected parameters and production costs. The additive material PLA Filament Plasty Mladeč proved to be the best with its properties and the second lowest price.

The aim of the work is to design and manufacture a mechanism for setting up and clamping the replaceable head of a 3D FDM printer. The first part of the thesis deals with 3D printing in general, the second part describes the FDM method. Part three is devoted to the selection and construction of a suitable 3D printer, the fourth part to the actual design of the head attachment. In the fifth part, a technical and economic evaluation is carried out.

Background: The submitted cumulative dissertation is based on two intertwined main studies with biomolecular foundation and clinical perspective on FUS-ALS complemented by two follow-up projects. This subtype of Amyotrophic lateral sclerosis is caused by heterozygous mutations mainly in the NLS of the FUS gene, which interferes with the proper nuclear import of the gene product. To date, there is no sufficient therapy available for this devastating neurodegenerative disease due to an incomplete pathophysiological understanding. Furthermore, not much is known about the specific clinical phenotype of FUS-ALS patients, including the influence of distinct FUS mutations due to the rarity of the disease. FUS is a DNA/RNA-binding protein that is mainly located in the nucleus and has essential functions in splicing, mRNA transport, transcription, and DNA damage repair. Hypothesis:1. It was hypothesized that the human-induced pluripotent stem-cell technique enables to create a sufficient motor neuron in-vitro cell model, which should provide new insights into unknown pathophysiological processes compared to previous cell models of FUS-ALS due to its patient-specific and human character. Thus, screening for potential therapeutic substances should be feasible using this model system. 2. Judging from the previously demonstrated, essential function of FUS in the DNA damage repair, FUS mutations are expected to increase the risk of malignant diseases in affected patients. Moreover, specific correlations between the nature of the mutation and the clinical, neurological phenotype appear plausible.Material & methods: First, an in-vitro cell culture model of FUS-ALS was established. For this purpose, a patient-specific, induced pluripotent stem cell-derived sMN culture was generated, which contained spinal motor neurons with mutations in the gene FUS or WT control cells. The Microfluidic Chamber system was used for the selective analysis of axons, which enabled the live-cell imaging of lysosomes and mitochondria using TIRF microscopy. For the analysis of DNA damage and its repair, gamma-H2A.X immunofluorescence staining was used on the one hand and live-cell laser ablation microscopy on the other, which allowed the precise induction of DNA damage and the monitoring of the repair response. For this purpose, isogenic FUS-GFP cell lines generated via CRISPR-Cas9n were used. A multicentre, retrospective cross-sectional study was conducted to determine genotype-phenotype correlations and the prevalence of malignant neoplasms in FUS-ALS. Previously published FUS-ALS cases have been added to perform a meta-analysis of clinical features.Results: Primarily, correct neuronal differentiation was observed prior to neurodegenerative phenotypes, perfectly mimicking a neurodegenerative disease in the dish. The typical cellular pathology of cytoplasmatic FUS deposition could be reproduced, making it a suitable model for more in-depth pathophysiological studies. Furthermore, the use of Microfluidic Chambers enabled the guided cultivation of neurons with somato-axonal direction of neurite outgrow along tiny microchannels in silico, resulting in a pure motoneuronal, axonal model. Within the distal axonal compartment of these channels, a loss of motility of both lysosomes and mitochondria was observed in parallel with a loss of the mitochondrial membrane potential, followed by the secondary degeneration of the distal axons of the sMNs with FUS mutation. A pathological increase in nuclear DNA damage has been identified as the cause of the distal-axonal phenotypes. This was due to a reduced nuclear FUS abundance as a result of the FUS-NLS mutation, which impaired proper nuclear import. There was evidence of a vicious cycle in this setting because the loss of the nuclear function of FUS disrupted the proper PAR-dependent DNA damage response, resulting in sustained DNA damage. Moreover, the remaining nuclear FUS was transferred into the cytoplasm upon phosphorylation by DNA-PK in a DNA damage response dependent manner, which is to date a process of unclear biological relevance. However, pharmacological inhibition of either the degradation of the PAR biopolymer or DNA-PK improved the nuclear presence of mutant FUS, restored its function in the DNA damage response, and finally prevented the distal axonal phenotype. Furthermore, the multicentric cohort study included 36 newly diagnosed patients. Only one in 40 patients was diagnosed with a malignant disease. By combining the newly diagnosed patients with previously published cases (186 cases in total), the so far most comprehensive database of FUS-ALS patients has been created. This allowed a thorough genotype-phenotype analysis, which showed a clear correlation between individual FUS mutations and the clinical phenotype. Conclusion: The experimental results indicated a primary nuclear insufficiency of mutated FUS, which is due to an impaired nuclear import and leads to a secondary axonal degeneration and finally to neuronal demise (“Dying-Back”). Potential therapeutic options have been identified, but their applicability and safety must be determined in prospective studies. The hypothesis of a generally increased risk of malignant diseases in the analysed FUS-ALS patient group was rejected. However, the clinical data of the meta-analysis are helpful in the counselling of newly diagnosed FUS-ALS patients, including the decision making of the therapeutic management and clearly add FUS-ALS to the family of diseases characterised by deficient DNA damage repair with purely neurological phenotypes such as AOA1, AOA2, and SCAN1.