SEARCH · Engineering Papers
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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The xEMU CAD model is a configuration controlled copy of the developing Exploration class Extravehicular Mobility Unit planned for demonstration on ISS and later for DSG and Planetary destinations.
A ProEngineer CAD model of the 11 Unitary Plan wind tunnel test section, diffuser inlet, plenum chamber, strut and aft diffuser has been created for use with analysis tools such as Cart3D and Star CCM+. Separate parts of the tunnel are created as parts files and assembled in an assembly file. Two merged solid parts are used for meshing. This report describes each of the parts files and features of the merged models.
SolidWorks models of the Modular Ocean Instrumentation System (MOIS) data acquisition system components in it's subsea enclosure. The zip file contains all the components necessary for the assembly.
Abstract not provided.
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Modeling and simulation lie at the heart of the design process of any nuclear application. An accurate representation of the radiation environment ensures not only the feasibility of new technologies, but it also aids in operation, maintenance, and even decommissioning. With increasingly complex designs, high-fidelity models have become a necessity for design maturity. McCAD has been under development for many years at Karlsruhe Institute of Technology (KIT) to facilitate the process of generating suitable models for nuclear analyses. In this paper, an overview of the major advances in the new version of the code is presented. A novel conversion algorithm has proven to be robust in significantly reducing the processing time to generate radiation transport models, making it easier to iterate on design details. A first-of-a-kind capability to generate hierarchical void cells is also discussed with preliminary analysis showing performance gains for particle tracking.
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Background: Patients with normal myocardial perfusion imaging (MPI) have a good prognosis. However, pre-clinical coronary and extracoronary atherosclerosis may exist in the absence of myocardial ischemia. Methods: 154 Egyptian patients (mean age 53 years) underwent whole-body non-contrast CT following normal MPI. Results: Atherosclerosis in the form of calcification was observed in ≥1 vascular bed in 115 of 154 (75%) patients. This included the iliofemoral (62%), abdominal aorta (53%), thoracic aorta (47%), coronary (47%), and carotid (25%) vascular beds. Mean total body calcium score was 3172 ± 530 AU. Extracoronary atherosclerosis in patients with a zero coronary artery calcium (CAC) score was common, occurring in the above-listed beds 42%, 36%, 29%, and 7% of the time, respectively. CAC was rarely present without iliofemoral or abdominal aortic calcification. Conclusion: Quantitative assessment of calcification in different vascular beds demonstrates that extracoronary atherosclerosis is common in patients who have normal MPI. Atherosclerotic calcifications are most common in the iliofemoral arteries and abdominal aorta, which typically predate coronary calcifications. An imaging strategy to detect extracoronary atherosclerosis could lead to greater understanding of the natural history of atherosclerosis in its long pre-clinical phase and possibly to earlier preventive strategies.
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Metal additive manufacturing (AM) offers flexibility and cost-effectiveness for printing complex parts but is limited to few alloys. Qualifying new alloys requires process parameter optimisation to produce consistent, high-quality components. High-resolution X-ray computed tomography (XCT) has not been effective for this task due to artifacts, slow scan speed, and costs. We propose a deep learning-based approach for rapid XCT acquisition and reconstruction of metal AM parts, leveraging computer-aided design models and physics-based simulations of nonlinear interactions between X-ray radiation and metals. This significantly reduces beam hardening and common XCT artifacts. We demonstrate high-throughput characterisation of over a hundred AlCe alloy components, quantifying improvements in characterisation time and quality compared to high-resolution microscopy and pycnometry. Our approach facilitates investigating the impact of process parameters and their geometry dependence in metal AM.
This is a conference paper about open source tools for circuit simulation and model compilers.
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