Concentrated solar power (CSP) plants have the potential to reduce the consumption of nonrenewable resources and greenhouse gas emissions in electricity production. In CSP systems, a field of heliostats focuses solar radiation on a central receiver, and energy is then transferred to a thermal power plant at high temperature. However,...
Waste heat driven ammonia/water Kalina cycles have shown promise for improving the efficiency of electricity production from low-temperature reservoirs (T < 150 °C). However, there has been limited application of these systems to utilize widely available, disperse, waste heat streams for smaller scale power production (1–10 kWe). Factors limiting increased deployment of these...
A novel thermal management approach is explored, which uses supercritical carbon dioxide (sCO2) as a working fluid to manage extreme heat fluxes in electronics cooling applications. In the pseudocritical region, sCO2 has extremely high volumetric thermal capacity, which can enable operation with low pumping requirements, and without the potential for...
Assembly time estimation is a key factor in evaluating the performance of the assembly process in an automated assembly process. The overall goal of this study is to develop an efficient assembly time estimation method by generating the prediction model from an experimental design. In order to estimate these times,...
The ternary system (Bi₀.₅Na₀.₅)TiO₃-(Bi₀.₅K₀.₅)TiO₃-Bi(Mg₀.₅Ti₀.₅)O₃ (BNT-BKT-BMgT) was explored along the [75-(x 2) ]Bi₀.₅Na₀.₅TiO₃ - [25-(x 2)]Bi₀.₅K₀.₅TiO₃ - [x]Bi(Mg₀.₅Ti₀.₅)O₃ composition line. Thin films were fabricated using chelated mixing route solutions spin cast onto platinized silicon substrates. Processing parameters such as: excess cation molar%, solution molality, and crystallization temperatures, for composition where x=0,...
Soft robots are designed to utilize their compliance and contortionistic abilities to both interact safely with their environment and move through it in ways a rigid robot cannot. To more completely achieve this, the robot should be made of as many soft components as possible. Here we present a completely...
The metal-organic–framework MOF-5 is used as an adsorbent in advanced systems for vehicular hydrogen storage that are currently under development. Presently, these systems are limited by poor thermal conductivity of the adsorption bed, and thus our research addresses how the interfaces between grains of MOF-5 can be engineered to improve...
Engineering applications often require fast, accurate solutions of fluid flow around freely moving bodies. The massive parallelism enabled by graphics processing unit (GPU) architecture enables high performance, offering a promising alternative to traditional solver acceleration via multicore central processing units (CPU). However, fully harnessing GPU parallelism requires specialized algorithms and...
Prepreg is widely used in composite manufacturing with advanced composites such as carbon and aramid. The material is characterized by a degree of flexibility (drape) and stickiness (tack), which allows an efficient layup on molds with complex shapes. However, axial instability of compressed fibers during the molding process may occur,...
In order to more effectively design large, complex systems, risk must be accounted for throughout the design process. A systematic way to account for risk is by using system model simulation. During the conceptual design phase, functional models can be drawn to help the engineer design their system's functional architecture....
This research investigates shape optimization process, using b-spline models and panel methods, to achieve a high lift to drag ratio for an aerodynamic structure. This research is a proof of concept for further research in aerodynamic shape optimization. The coupled process, involving the design and optimization of a random shape,...
Large-hydrocarbon fuels are used for ground and air transportation because of their high energy-density and will be for the foreseeable future. However, combustion of large-hydrocarbon fuels in a turbulent environment is poorly understood and difficult to predict. The turbulent flame speed, which is the velocity at which a flame front...
Vacuum arc remelting (VAR) is a secondary melting process for exotic alloys. The main purpose of this process is to increase the input ingot’s physical and chemical homogeneity. This is accomplished through the application of a high current that melts the material through the emergence of electrical arcs that induce...
The demand from consumers for more sustainable products, and the need to comply with government regulations motivates manufacturers to evaluate their operations for opportunities to reduce environmental impact and improve economic competitiveness. Manufacturers have actively improved the sustainability performance of their products through the use of sustainability assessment methods and...
Radio frequency identification (RFID) has long been regarded as an automated data collection technology that promises solutions to inefficiencies found in supply chains such as “just-in-case” inventory stock, inventory obsolescence, stockouts, and theft. However, the disappointingly slow return on RFID investment has forced companies to examine and redefine RFID initiatives....
Intermodal freight transportation uses at least two different transportation modes (e.g., truck, rail, ship, air) to move freight loads that are in the same transportation unit (e.g., a shipping container) from origin to destination without handling the goods themselves. The increasing shift to intermodal transportation and the growth of freight...
Cellulose nanocrystals (CNCs) are extremely abundant, biodegradable and light weight nanoparticles that have the potential to contribute in many fields including packaging, construction, solar cells and automotive. With the increasing interest in nanotechnology and nanocomposites, CNCs could provide a renewable, optically transparent and strong alternative to other nano-scale reinforcement phases....
Chainsaws, an indispensable tool for modern forestry operations, rely on bar lubricant to prevent rapid wear of the chain and bar. Choice of bar lubricant must balance performance, cost, and biological impact. Many bar lubricants are available, but little published work exists that conclusively ranks the performance of these choices....
High performance dielectric materials are needed for high power SiC- or GaN-based electronics which combine the best features of high energy density, low dielectric loss and high reliability and for advanced high-speed and high-voltage energy storage where temperature stability plays an important role in material properties. An ideal capacitor for...
This study computationally and experimentally examines the mechanisms of crack penetration, deflection and the transition between penetration and deflection. The finite element analysis based computational modeling work used strength-and-energy based cohesive-zone approach to study the effect of dimensionless parameters (e.g., interfacial incident angle, fracture-length scale, and normalized toughness) on penetration/deflection...
Composites often are able to carry more load after damage due to the structure of laminates. In addition, damage can be difficult to detect in composites compared to homogeneous materials. Understanding the behavior of composite material after damage is vital for composite structural design. Currently, experimental methods exist for classifying...
In the past half century, industrial robots have developed a strong presence in manufacturing. They now commonly perform tasks such as materials handling, assembly, welding, and painting. Unfortunately robotic machining tasks have seen limited deployments. The majority of machining robots are designed for soft materials like wood or plastic and...
New materials with superior mechanical properties, such as increased strength and hardness, have been developed to allow for new and improved products. However, the mechanical properties that make these materials useful also makes them difficult to process using conventional methods. New machining processes need to be developed to generate products...
Integrated manufacturing systems, a combination of subtractive, additive, and joining processes, provide a competitive advantage for manufacturing organizations. As product designs become more complex and capital more scarce, an ideal combination of advanced manufacturing technologies (e.g., powder bed fusion or friction welding), in tandem with traditional subtractive manufacturing systems, can...
There is a strong interest in the robotics community in learning how humans grasp and manipulate objects, partly because robots need to operate in human environments and partly because humans are currently much better in physical interaction tasks than robots. This thesis seeks to identify the human heuristics for grasping...
This thesis explores the use of human kinesthetic input to advance robotic grasp planning. It specifically focuses on identification of human heuristics of grasp similarity by extensive human-subject experiments. This heuristic is then utilized to develop a robust metric for identifying similar robotic grasps. The central hypothesis of this work...
This paper presents a system of modeling advances that can be applied in the computational optimization of wind plants. These modeling advances include accurate cost and power modeling, partial wake interaction, and the effects of varying atmospheric stability. To validate the use of this advanced modeling system, it is employed...
Autonomous multiagent teams can be used in complex exploration tasks to both expedite the exploration and improve the efficiency. However, use of multiagent systems presents additional challenges. Specifically, in domains where the agents' actions are tightly coupled, coordinating multiple agents to achieve cooperative behavior at the group level is difficult....
The Moderate or Intense Low-oxygen Dilution (MILD) combustion regime has received interest from the industrial furnace and gas turbine engine industries due to attractive properties of reduced NO[subscript x] emissions and high thermal efficiency. MILD combustion is characterized by low oxygen concentrations (i.e. 3%-9% by volume) and high reactant temperatures....
Growing awareness and concern within society over the use of and reliance on fossil fuels has stimulated research efforts in identifying, developing, and selecting alternative energy sources and energy technologies. Bioenergy represents a promising replacement for conventional energy, due to reduced environmental impacts and broad applicability. Sustainable energy challenges, however,...
This thesis is the combination of two research publications working toward a unified strategy in which the design of complex engineered systems can be completed using a multiagent coordination approach. Current engineered system modeling techniques segment large complex models into multiple groups to be simulated independently. These methods restrict the...
Unmanned aerial vehicle (UAV) technology has grown out of traditional research and military applications and has captivated the commercial and consumer markets, showing the ability to perform a spectrum of autonomous functions. This technology has the capability of saving lives in search and rescue, fighting wildfires in environmental monitoring, and...
Additive manufacturing (AM) is a relatively new manufacturing technique that can create high complexity parts out of many materials in low volume. The fused filament fabrication (FFF) is the lowest cost AM process and is capable of producing only thermoplastic components. Powder injection molding (PIM) is a high volume low...
The ability to jump allows small robots to traverse rough terrain, clear large obstacles, and quickly reach elevated locations. These abilities have applications in a variety of areas such as, search and rescue, environmental monitoring, and urban warfare. The primary focus in current state-of-the-art jumping robots has been on jumping...
Variations in heat treatments have significant effects on the microstructure of tool steels. For CPM-M4 tool steel, the changes in microstructure and mechanical properties were observed based off of variations in temperature. Five heat treatments with constant exposure time and variable austenitizing and tempering temperatures were performed on samples of...
Many projects fail because employees and managers have different understandings of project "success" or "value". Other projects fail because managers are unable to effectively align organizational values with those of their employees. This problem is widely understood, but there is little empirical research that specifies the nature and effect of...
Small and medium-sized enterprises that are characterized by high-mix, low-volume, and highly variable production operations often have unstructured material movement processes that are prone to material handling wastes. These sub-optimal material handling systems are oftentimes a result of small and medium-sized enterprise's limited resources. Current tools to assist organizations in...
Robots have the potential to protect health care workers, provide patient care, and ultimately save lives in infectious disease outbreaks. Nevertheless, infectious disease outbreak scenarios present unique technological and social challenges for robotics. This work explores what robots can and should do in the fight against infectious diseases. We present...
Designing a carbon fiber chassis for the Global Formula Race car has historically proven to be both time intensive and difficult. The goal of this thesis is to improve the design process for testing Global Formula Racing team's composite chassis sandwich panels. Consideration was taken regarding Formula SAE rules, and...
Poor material utilization is inherent to conventional manufacturing processes, leading to high material waste and machining times. Additive manufacturing processes attempt to solve this issue by allowing production of near-net shapes, but the processes may be too expensive or infeasible. By leveraging both processes in a single part, the waste...
The large wind resource off the United States West Coast has the potential to generate wind power for millions of homes, yet the high cost of energy for offshore wind power compared to traditional sources has slowed the development of offshore wind farms in the US. The four studies presented...
Sustainable product design is becoming an important component of the development of consumer products. Currently there are limited design resources to aid in the creation of environmentally sustainable products. The purpose of this research is to theorize a new method for integrating sustainable design knowledge into the early design phase...
Cultural differences between designers and users is an important aspect to consider when designing products for other countries. However, many prominent authors in the human factors engineering field have failed to specifically address how to identify and utilize cultural differences in user interface (UI) design. This research evaluated if design...
Flexible aerodynamic surfaces have been shown to favorably influence flight characteristics at low Reynolds numbers by increasing lift, angle of attack at stall, and resistance to perturbation. The objective of the research presented within this thesis is to investigate the influence of two aspects of flight observed in biological flyers,...
To manage the effects of manufacturing industries on the economy and environment, design tools are needed that will aid engineers to assess manufacturing costs and environmental impacts early in design. The development of cost analyses and environmental assessments can be burdensome, but much of the data used in these analyses...
This thesis details the applications of a new method of agent-based structure synthesis. The goal of this research is to create structures that meet a structural goal within a simulated physics environment. The method proposed works as an iterative process of changing the structure, evaluating the new structure and using...
The purpose of this study is to measure and compare radiation emissions from flames burning large hydrocarbon fuels to assist in understanding how the molecular composition changes radiation emissions. Radiative heat transfer is significant because it is a primary mode of heat transfer for many combustion devices. This study also...
Turbulent flows over rough surfaces are encountered in many engineering and geophysical applications. Flows of this nature, due to their increasing technological interests, have been a subject of rigorous investigation in recent years. Of the particular interest to the oceanographic community is the study of turbulent oscillatory flow over rough...
This thesis examines the effect of aerodynamics on Formula SAE cars. Due to the different objectives of the Formula SAE events, an understanding of the car's complete aerodynamic design is necessary. Using a half car computational fluid dynamics (CFD) model, a series of sensitivity studies are conducted to determine trends...
Broadband absorption spectroscopy, by way of FTIR, was used to investigate the vapor cloud of a single millimeter sized liquid droplet suspended by a syringe as it evaporates at standard conditions. Single beam data were collected every 8 seconds resulting in a time-resolved record. Species concentrations were tracked using their...
Assessing student conceptual understanding is a valuable method for gauging specific student learning outcomes but can be difficult and time consuming to measure. This research investigates the potential of automating some intermediary steps of a qualitative analysis of student conceptual understanding with tools from the field of Natural Language Processing...
The objective of this paper is to demonstrate a method for mechanically characterizing a 25 μm thick elastoviscoplastic hemodialysis membrane and for quantifying the force required to use that membrane in compression sealing. First, methods are developed for mechanically characterizing the thin elastoviscoplastic membrane. Then, a finite element model is...