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Full-Text Articles in Engineering

Cybersecurity Planning For Artificial Intelligent Systems In Space, Gary Langford, Lucas Beaulieu, Jeffery Carpenter, Ian Watkins, Brock Marsh, Teah Heidorn, Chris Chase Jan 2019

Cybersecurity Planning For Artificial Intelligent Systems In Space, Gary Langford, Lucas Beaulieu, Jeffery Carpenter, Ian Watkins, Brock Marsh, Teah Heidorn, Chris Chase

Engineering and Technology Management Faculty Publications and Presentations

CubeSats continue to proliferate and are an excellent low-cost method of remote sensing. A key piece of intelligent systems is sensory input, data storage, and data communications. With the continued miniaturization of technology, CubeSats will increase their sensory inputs with future miniaturization and enhance their robustness for autonomous operations if data and communications are secure. These futures inspire an intelligent system solution to on-orbit communications. This paper explores a dual-microprocessor approach to improve hardware cybersecurity of intelligent systems, with a view toward intensional intelligence as a means of adjudicating access to sensitive data onboard the CubeSat. With enhanced cybersecurity, Artificial …


Flip-Chip (Fc) And Fine-Pitch-Ball-Grid-Array (Fpbga) Underfills For Application In Aerospace Electronics—Brief Review, Ephraim Suhir, Reza Ghaffarian Jul 2018

Flip-Chip (Fc) And Fine-Pitch-Ball-Grid-Array (Fpbga) Underfills For Application In Aerospace Electronics—Brief Review, Ephraim Suhir, Reza Ghaffarian

Mechanical and Materials Engineering Faculty Publications and Presentations

In this review, some major aspects of the current underfill technologies for flip-chip (FC) and fine-pitch-ball-grid-array (FPBGA), including chip-size packaging (CSP), are addressed, with an emphasis on applications, such as aerospace electronics, for which high reliability level is imperative. The following aspects of the FC and FPGGA technologies are considered: attributes of the FC and FPBGA structures and technologies; underfill-induced stresses; the roles of the glass transition temperature (Tg) of the underfill materials; some major attributes of the lead-free solder systems with underfill; reliability-related issues; thermal fatigue of the underfilled solder joints; warpage-related issues; attributes of accelerated life …


Thermally Stable Super-Hydrophobic Surface Creation, Caleb Turner May 2018

Thermally Stable Super-Hydrophobic Surface Creation, Caleb Turner

Undergraduate Research & Mentoring Program

Thermally stable super-hydrophobic surface coatings are critical to applications in low gravity fluid dynamics, and in particular Leidenfrost effects. The challenges of manufacturing different super-hydrophobic coatings that are thermally stable, semi-transparent, and environmentally safe at desired operating temperatures is pursued in order to explore the applications of such coatings aboard spacecraft. A catalog of surface coating manufacturing procedures is tabulated with measures for static contact angle, thermal stability, and transparency. These quantities and methods serve as a foundation for both technology applications and follow on experimentation concerning low gravity fluid mechanics at the Portland State Dryden Drop Tower lab.


Aerospace Mission Outcome: Predictive Modeling, Ephraim Suhir May 2018

Aerospace Mission Outcome: Predictive Modeling, Ephraim Suhir

Mechanical and Materials Engineering Faculty Publications and Presentations

Human-in-the-Loop (HITL)-related models can be applied in various aerospace vehicular problems, when human qualifications and performance are crucial and the ability to quantify them is therefore imperative; since nobody is perfect, these evaluations should preferably be done on a probabilistic basis. The suggested models can also be used in many other areas of applied science and engineering, not even necessarily vehicular engineering, when a human encounters an extraordinary situation and should possess a sufficiently high human capacity factor (HCF) to successfully cope with an elevated mental workload (MWL). The incentive for probabilistic predictive modeling and the rationale for such modeling …


Fifty-Plus-Year Postflight Analysis Of First Fluid Experiment Aboard A Spacecraft, Mark M. Weislogel, Yongkang Chen, William J. Masica, Fred J. Kohl, Robert D. Green Jan 2017

Fifty-Plus-Year Postflight Analysis Of First Fluid Experiment Aboard A Spacecraft, Mark M. Weislogel, Yongkang Chen, William J. Masica, Fred J. Kohl, Robert D. Green

Mechanical and Materials Engineering Faculty Publications and Presentations

This year marks the 55th anniversary of the first fluid physics experiment performed aboard a spacecraft during the Mercury-Atlas 7 mission. Since then, NASA has conducted over 80 fluids physics experiments aboard a variety of spacecraft, many of which have enhanced the understanding of large-length-scale capillary phenomena relevant to liquid management in the weightless state. As both celebration and demonstration, the Mercury-Atlas 7 fluids experiment is revisited in light of the current understanding of large-length-scale capillary fluidics. Employing a modern numerical tool, a rich variety of experimental outcomes are discovered that were not observed during the flight experiment. Interestingly, experimental …


Passive Phase Separation Of Microgravity Bubbly Flows Using Conduit Geometry, Ryan M. Jenson, Andrew Paul Wollman, Mark M. Weislogel, Lauren Sharp, Robert Green, Peter J. Canfield, Jörg Klatte, Michael E. Dreyer Oct 2014

Passive Phase Separation Of Microgravity Bubbly Flows Using Conduit Geometry, Ryan M. Jenson, Andrew Paul Wollman, Mark M. Weislogel, Lauren Sharp, Robert Green, Peter J. Canfield, Jörg Klatte, Michael E. Dreyer

Mechanical and Materials Engineering Faculty Publications and Presentations

The ability to separate liquid and gas phases in the absence of a gravitational acceleration has proven a challenge to engineers since the inception of space exploration. Due to our singular experience with terrestrial systems, artificial body forces are often imparted in multiphase fluid systems aboard spacecraft to reproduce the buoyancy effect. This approach tends to be inefficient, adding complexity, resources, and failure modes. Ever present in multiphase phenomena, the forces of surface tension can be exploited to aid passive phase separations where performance characteristics are determined solely by geometric design and system wettability. Said systems may be readily designed …


Experimental Study On Influence Of Pitch Motion On The Wake Of A Floating Wind Turbine Model, Stanislav Rockel, Elizabeth Camp, Jonas Schmidt, Joachim Peinke, Raúl Bayoán Cal, Michael Höllimg Mar 2014

Experimental Study On Influence Of Pitch Motion On The Wake Of A Floating Wind Turbine Model, Stanislav Rockel, Elizabeth Camp, Jonas Schmidt, Joachim Peinke, Raúl Bayoán Cal, Michael Höllimg

Mechanical and Materials Engineering Faculty Publications and Presentations

Wind tunnel experiments were performed, where the development of the wake of a model wind turbine was measured using stereo Particle Image Velocimetry to observe the influence of platform pitch motion. The wakes of a classical bottom fixed turbine and a streamwise oscillating turbine are compared. Results indicate that platform pitch creates an upward shift in all components of the flow and their fluctuations. The vertical flow created by the pitch motion as well as the reduced entrainment of kinetic energy from undisturbed flows above the turbine result in potentially higher loads and less available kinetic energy for a downwind …


Capillary-Driven Flows Along Rounded Interior Corners, Yongkang Chen, Mark M. Weislogel, Cory L. Nardin Nov 2006

Capillary-Driven Flows Along Rounded Interior Corners, Yongkang Chen, Mark M. Weislogel, Cory L. Nardin

Mechanical and Materials Engineering Faculty Publications and Presentations

The problem of low-gravity isothermal capillary flow along interior corners that are rounded is revisited analytically in this work. By careful selection of geometric length scales and through the introduction of a new geometric scaling parameter Tc, the Navier–Stokes equation is reduced to a convenient∼O(1) form for both analytic and numeric solutions for all values of corner half-angle α and corner roundedness ratio λ for perfectly wetting fluids. The scaling and analysis of the problem captures much of the intricate geometric dependence of the viscous resistance and significantly reduces the reliance on numerical data compared with several previous solution methods …