Transient liquid-phase diffusion brazing is used in precision, hermetic joining applications as a replacement for diffusion bonding to reduce cycle times, reduce bonding pressure and improve yields. Studies showed that the interlayer used in diffusion brazing can be detrimental due to the use of melting point depressants (MPDs). The goal...
Computing agents require state information to make coherent and useful decisions. A state representation is a numerical translation of the environment and conditions that are pertinent factors in an agent's decision making. Although many representations, when paired with clever learning algorithms, are able to coordinate and capture prey in specific...
Data from a state department of transportation fleet shows that the usage of a typical asset decreases as it ages. One possible explanation for decreasing asset usage with age is operator preference for using the newest available asset. In this research the long-term cost and replacement implications of such a...
Distractions and interruptions are common occurrences in an operating room (OR), but little is known about their effects on surgical task performance. Based on human factors research, it was hypothesized that realistic distractions and interruptions in an OR would adversely impact surgical task performance. Because of the concern of patient...
Ocean Wave Energy Converters (WECs) operating on the water surface are subject to storms and other extreme events. In particular, high and steep waves, especially breaking waves, are likely the most dangerous to WECs. A method for quantifying the breaking severity of waves is presented and applied to wave data...
Aerodynamic improvements in automotive racing can have a significant effect
on vehicle performance. Recent developments in Formula SAE (Society of
Automotive Engineers) have included the design and implementation of aerodynamic
devices such as inverted wings and undertrays to improve performance. In this work
the literature of undertray technology is presented...
This research studied the role of shared ownership on virtual team effectiveness, using student teams enrolled in engineering management coursework at Oregon State University and Virginia Polytechnic Institute. After a thorough review of the literature, the concept of shared ownership was developed. This concept was operationalized as the extent to...
Since the Industrial Revolution, automated systems have increasingly become a part of everyday life. Automated systems range in scale and scope from simple assists to complete robotic replacements. Inexpensive integrated circuits, sensors and microprocessors have allowed automated systems to become smaller, cheaper and more prevalent. Identifying appropriate opportunities for automation,...
Continuous Improvement (CI) is an integral part of hospital administration. This study examined the relationship between five CI variables against six hospital criterion measures of, wait times to prepare a room, patient costs per day, waiting time for lab results, reportable errors, patient satisfaction, and employee satisfaction. The research was...
The substantial wave energy resource of the US Pacific Northwest (i.e. off the coasts of Washington, Oregon and N. California) is assessed and characterized. Archived spectral records from ten wave measurement buoys, operated and maintained by the National Data Buoy Center and the Coastal Data Information Program, form the basis...
Numerical modeling of methane-steam reforming is performed in a micro/mini-channel with heat input through catalytic channel walls. The low-Mach number, variable density Navier-Stokes equations together with multicomponent reactions are solved using a parallel numerical framework. Methane-steam reforming is modeled by three reduced-order reactions occurring on the reactor walls. The surface...
Steam-methane reforming is a well understood industrial process used for generating hydrogen and synthesis gas. The reaction is generally carried out with residence times on the order of one second. By performing this reaction at microscales it is possible to take advantage of increased heat transfer rates and low diffusion...
The field of nanotechnology has been rapidly developing new materials. These materials have become incorporated into consumer products and the environment after only minimal assessment of their effects on human health or the environment. The toxicity of these new nanomaterials remains unknown due to the unpredictable nature of the core...
Currently, the temporal arc distribution across the ingot during the vacuum arc remelting (VAR) process is not a known or monitored parameter. It is has previously been shown that arcs can spatially constrict during VAR, and this constriction can lead to undesired defects in the material. Additionally, correct accounting for...
Qualitative data analysis (QDA) is a time consuming and, potentially unreliable research activity. In qualitative research, a number of tasks must be repeated for every new research case, even if each case is closely related or is in the same area of study.
Existing QDA applications provide users with a...
Novel fluidic devices that utilize an array of microchannels to achieve their designed purpose are discussed. Examples of devices include: fuel reforming using Microreactors, chip cooling using microchannel heat sinks, and microchannel devices used for biological applications. The devices that have directly contributed to this research include: a microchannel water...
Customer requirements and engineering specifications will influence the direction of the design in any product, so it is crucial to make the requirements as stable as possible so quality designs can be produced on time within a budget. It would be optimal for requirements and specifications to remain constant but...
Over the last few decades, the methods and tools through which humans collaborate, share knowledge and generally communicate have been advancing at a rapid pace. Thanks mostly to advances in broadband internet, cheap data storage and fast microprocessors, humans now have the ability to work together in ways that even...
Behavioral modeling is increasingly an imperative component of system design as the systems under construction become more and more complex. Without behavioral modeling available to the modern designer, design and verification of these systems would be much more laborious. Additionally, with the increasing computational power of today's modeling and simulation...
Spray impingement cooling has been shown to be a leading candidate for future high heat flux cooling applications. In general, spray cooling curves consist of three heat flux regimes; single-phase, two-phase and critical heat flux (CHF). CHF is considered the design limit for almost all two-phase cooling applications, as a...
Biological organisms, phenomena and strategies, herein referred to as biological systems, provide a rich set of analogies that can be used to inspire engineering innovation. Biologically-inspired, or biomimetic, designs are publicly viewed as creative and novel solutions to human problems. Moreover, some biomimetic designs have become so commonplace that it...
A significant barrier to the diffusion bonding of large (i.e. 600 mm) microchannel devices is the large capital investment required to setup production. This large capital investment extends from long heating and cooling cycles leading to poor production
capacities. Empirical studies in industry have shown that cooling rate is limited...
Microchannel arrays are being developed across a wide spectrum of microfluidic applications including blood processing, fuel cells and thermal management among many others. Typical arrays are based on a flat laminated architecture produced in a vacuum hot press (VHP) through solid-state diffusion bonding. Due to the cylindrical nature of certain...
The performance of a combined Stirling-ORC power cycle is evaluated, and an integrated microchannel heat exchanger is designed as an annular cold-side heat rejector for a free piston Stirling engine. Reasonable designs for a combined cycle can increased power output efficiency by 3 - 9% compared to that of a...
The organic Rankine cycle (ORC) is a versatile approach in the utilization of waste heat in the production of electricity, clean drinking water, and cooling. The efficiency of these cycles must be maximized to make them economical. Parameters for the optimization of ORCs such as evaporator and condenser temperature have...
Uninhabited aerial vehicles, also called UAVs are currently controller by a combination of a human pilot at a remote location, and autopilot systems similar to those found on commercial aircraft. As UAVs transition from remote piloting to fully autonomous operation, control laws must be developed for the tasks to be...
Silicon carbide (SiC) and aluminum nitride (AlN) exhibit a combination of thermal and mechanical properties that are relevant to applications in electronics, aerospace, defense and automotive industries. However, the successful translation of these properties into final applications lies in the net-shaping of these ceramics into fully dense microstructures. Increasing the...
Photovoltaic (PV) cells have long been an attractive alternative for the consumption of fossil fuels but current manufacturing practices suffer from poor energy efficiency, large carbon footprints, low material utilization, high processing temperatures and high solvent usage. A critical step in PV production is the deposition of CdS as a...
Hot engine exhaust and industrial process exhaust represents a resource that is often rejected to the environment without further utilization. This resource is prevalent in the transportation and industrial process sectors, but stationary engine-generator systems also typically do not utilize this resource. Engine exhaust is considered high grade heat and...
Particle-laden turbulent flows are of great importance in many industrial
applications and are sufficiently complex to require multiple methods of study to
provide a better understanding of the dominant physical mechanisms present in
these processes. This work on large-eddy simulation of particle-laden flows seeks
to help provide the building blocks...
Fractal-like branching microchannel flow networks have been found to improve wall temperature uniformity and decrease both pressure drop and flow power compared to arrays of straight microchannels. The present study seeks to maximize the benefits of fractal-like branching channels by means of a gradient-based optimization algorithm. The algorithm identifies the...
Population counts of aquatic insects can be a credible indicator of the overall health of a waterway. Stonefly (Plecoptera) larva are very sensitive to chemicals present within the waterway, however obtaining population counts of the larvae can be very labor intensive and thus costly. The BugID project has been working...
This research studied the relationship between three input variables and outcomes related to the use of quality circles (QCC) in a Chinese manufacturing company. After a thorough review of the literature, three managerial input variables were identified, including goal clarity, goal difficulty, and management support. Five outcomes were measured, including...
For manufacturing and service industries to stay competitive in this rapidly changing, globalized world, one of the most important operations, and one that many businesses struggle to plan and manage efficiently, is material handling. There has been a large amount of research on various vehicle routing problems (VRPs) in recent...
In the current study a thermally activated cooling system that combines an ORC system with a vapor compression cooling cycle was developed and tested under laboratory conditions. This combined system
can utilize waste heat or other thermal sources such as solar and geothermal to generate power and
cooling. Hot oil...
Heat activated cooling has the potential of utilizing thermal sources that currently go unused such as engine exhaust heat or industrial waste heat. Using these heat sources can provide enhanced energy utilization and reduced fuel usage in applications where cooling is needed. The concept developed here uses waste heat from...
Wave energy conversion is still in its infancy, and in order for it to become a commercially viable technology, developers, investors and utilities need to estimate a Wave Energy Converter's (WEC's) performance for the wave climate of a potential installation site. With the goal of estimating a design's power output...
Training is a key business process used to increase the skills and knowledge of employees in an effort to improve overall performance. Evaluation of the effectiveness and efficiency of training processes is necessary to ensure time, money, and resources are used to provide the most benefit possible. This investigation is...
This thesis presents a feasibility study of a means to passively effect liquid motion parallel to a heated surface though surface geometrical modifications. Such a passive system is beneficial for electronics cooling applications as it reduces the pumping equipment normally required in flow loops and is desired for space applications,...
Innovation can be considered the driving force behind product design. This thesis strives to improve the ease at which innovation is achieved. Firstly by examining how design information is presented and comprehended by various personality types. The Myers-Briggs Type Indicator test is a quick, easy, and accurate way to determine...
Lean manufacturing, or more generally continuous improvement (CI), has been the methodology behind significant improvements in quality, work in process inventory reductions, lead time reduction and cost reduction while conversely being associated with failed implementations and occasionally with unpopular work practices. This research focused on promoting understanding of CI methodology...
Experiments on a novel, microscale hydrogen combustor heat exchanger (µCHX) are presented in this thesis. The µCHX has been designed to efficiently transfer thermal energy to a heat transfer fluid for use in desorption of hydrogen from a metal hydride storage system of a hydrogen-powered fuel cell vehicle. The experimental...
A flexible flowshop, comprised of one or more stages having unrelated parallel machines, is investigated in this research. Unrelated parallel machines can perform the same function but have different capacity or capability. Since this problem is motivated by industry research, dynamic job release times and dynamic machine availability times have...
Micro- and nanotechnologies are promising advancements across many industrial sectors, including alternative energy, chemical processing, and healthcare. In particular, a focus of research has been in manufacturing process development aimed at microdevice cost reduction and quality improvement. Microdevices take advantage of enhanced heat and mass transfer to improve energy and...
In cases where complex systems routinely experience extreme operating conditions, preventative maintenance is often employed to guard against system failure. Yet, with accessible real-time data and the standard practice becoming prohibitively expensive, the test stand can serve as a vital contributor to the development of system health and reliability estimations....
Future engineers need to be competitive in today's expanding global industries. They must have capabilities beyond standard engineering practice. In an attempt to develop students capable of working in a globally distributed design and manufacturing environment, Oregon State University (OSU) and Duale Hochschule Baden-Württemberg Ravensburg (DHBW) have developed a senior...
Most existing methods for generating individual task time estimates in production systems where jobs move through various manually operated workstations remain tedious and time consuming. For existing systems, average task times may vary considerably from prior estimates causing system inefficiencies, poor scheduling and poor planning decisions. Accurate and up-to-date estimates...
The objective of this research was to provide a definitive description of the processes within the physician-patient encounter in an office setting. This description would take the form of a formal process model of the encounter in a provider's office setting, as this represents the most common situation during patient...
Increasing access to modern forms of energy in developing countries is a
crucial component to eliminating extreme poverty around the world. Pico-hydro
schemes (less than 5-kW range) can provide environmentally sustainable electricity
and mechanical power to rural communities, generally more cost-effectively than
diesel/gasoline generators, wind turbines, or solar photovoltaic systems....
A number of computational tools now exist to aid in developing conceptual solutions based on a functional description of a design problem. A key limitation of these tools is the way results are organized for presentation to the user. In general, results are an undifferentiated mass of potential solutions. Analysis...