Advancements in fabrication of manufacturing and medical systems is focusing on using computer-aided fabrication methods, also called additive manufacturing or 3D printing. In civil engineering, we still rely on traditional methods of construction. Although there are researchers and companies investigating 3D printing of concrete, most focus on form, not on engineering properties. This research project has begun to remedy that by investigating mix design methodologies, new extrusion techniques and use of large-capacity testing equipment to advance engineering of 3D printed concrete structures. The first phase has investigated extrudable and stable (in its fresh state) mix design(s); a new protocol is being developed to test the engineering properties, including stiffness, strength of the extruded material, as well as multi-layer adhesion and deformation. The second phase will investigate the hardened properties. The research is funded by Pactrans, with the ultimate goal of printing components for multi-modal concrete structures, such as pedestrian and bicycle bridges.

Altrenogest (ALT) is a potent synthetic steroidal progestin commonly used as a veterinary pharmaceutical to maintain pregnancy in females, match estrus periods for breeding, or postpone the estrus period. ALT usage was estimated as several thousand kg across ~3,600,000 horses and ~66,000,000 swine; it subsequently enters the aquatic environment through agricultural runoff. ALT can act as an environmental endocrine disruptor because it has progestogenic and androgenic activity, however, little is currently known on its environmental fate, persistence, and ecological risks. Our study focuses on characterizing the biodegradation kinetics and product identification for ALT and its primary photoproducts.To evaluate altrenogest fate, we build microcosms by mixing altrenogest, water and growth media for mixed microbial communities collected from representative agro-ecosystems and municipal waste waters. We then concentrate water samples through solid- phase extraction and then use liquid chromatography and triple quadrupole mass spectrometry to analyze remaining ALT concentrations over time, to understand transformation kinetics. To identify transformation products, sample extracts are analyzed using high resolution mass spectrometry. Study results will aid in the risk assessment of ALT by improving our understanding of its environmental fate and management.

The University of Washington High Enthalpy Flow Laboratory (HEFL) has constructed a purpose built laboratory for experimental research on Rotating Detonation Engines (RDE). This refit included the rebuilding of the lab apparatus, the assembly of the RDE and supporting equipment such as downstream piping, vacuum system, gas handling plumbing, and the redevelopment of the experimental instrumentation. The assembly of the lab apparatus consisted of the construction and mounting of fuel, oxygen, and nitrogen lines for the RDE, and the assembly of back pressure controlled exhaust tubes leading to a dump tank and an optical imaging port. A stand for the engine apparatus itself as well as much of the plumbing support equipment was also constructed. The assembly of the RDE consisted of the assembly of the various engine parts, followed by the connection of the various instruments such as pressure sensors, temperature sensors, ion probes to the engine itself. The hardware and software components of the instrumentation systems were also redeveloped to allow for very high instrument density for pressure and temperature sensors on the RDE. The software component of the instrumentation involved developing MATLAB scripts for valve actuation, data acquisition, and sensor calibration. The hardware aspect of the instrumentation involved selecting the sensors to be used on the engine based on their signal conditioning, as well as designing and building power supply and signal processing circuits to connect the sensors to a rebuilt data acquisition computer system.

An often conceptually difficult topic learned in early engineering courses is known as the angle of twist. The angle of twist is necessary for two reasons: to analyze reactions along a shaft where traditional equilibrium equations do not suffice, and in designing a shaft when twisting is restricted. In this project, the purpose is to design and build a device that will be an aid in classroom demonstrations of the concept and applications of the angle of twist. The prototype of this device is designed to test foam shafts of a certain length and with a constant applied torque. The device will need to support, hold, and twist foam shafts while providing precise measurements of the applied torque and the resulting angle of twist. Two markers will be put in place before twisting. The shaft will be fixed at one end, where one marker will be in place, and twisted at the opposite end where the mobile marker will be used to determine the angle between the two. It must be durable to withstand regular classroom handling and have an appropriate interface for students of varying levels of proficiency in the topic. Its design must also be inexpensive and replicable so that it can be built and used within a low classroom budget. Students will be able to calculate, measure, and observe the applications of polar moment of inertia, angle of twist, and torque using the measurements from the apparatus. From the measurements, the shear modulus of the shaft material will be experimentally determined, allowing for an active learning experience of this key concept.An often conceptually difficult topic learned in early engineering courses is known as the angle of twist. The angle of twist is necessary for two reasons: to analyze reactions along a shaft where traditional equilibrium equations do not suffice, and in designing a shaft when twisting is restricted. In this project, the purpose is to design and build a device that will be an aid in classroom demonstrations of the concept and applications of the angle of twist. The prototype of this device is designed to test foam shafts of a certain length and with a constant applied torque. The device will need to support, hold, and twist foam shafts while providing precise measurements of the applied torque and the resulting angle of twist. Two markers will be put in place before twisting. The shaft will be fixed at one end, where one marker will be in place, and twisted at the opposite end where the mobile marker will be used to determine the angle between the two. It must be durable to withstand regular classroom handling and have an appropriate interface to be used by students of varying levels of proficiency in the topic. Its design must also be inexpensive and replicable so that it can be built and used within a low classroom budget. Students will be able to calculate, measure, and observe the applications of polar moment of inertia, angle of twist, and torque using the measurements from the apparatus. From the measurements, the shear modulus of the shaft material will be experimentally determined, allowing for an active learning experience of this key concept.

Freshwater is one of the most valuable resources in Washington State. In recent decades, water supply has been affected due to climate change and population growth. Understanding changes in water supply and demand is crucial for ensuring an abundance of water for residential, economic, and industrial needs. The proposed research analyzes changes in the streamflow regime of the Cedar and Tolt Rivers which provide drinking water for the greater Seattle area. The main goal is to calculate the water budgets for the Cedar and Tolt watersheds and estimate how the inputs and outputs to these budgets change over the 21st century. An existing ensemble of streamflow projections for the Cedar and Tolt Rivers are used to analyze changes in water supply. The mean streamflow for each month is compared between a 30-year control period (water years 1971-2000) and a 30-year future period (water years 2031-2060). For each of these periods, I determine “optimistic” and “pessimistic” scenarios for the streamflow. For the “drought” month the highest streamflow value is considered as “optimistic”, and the lowest as “pessimistic” since the goal is to assess potential shortages. I use existing monthly demand values provided by Seattle Public Utilities and create different future scenarios, based on the predictions of population and employment growth. Supply and demand values are compared to evaluate (1) the potential for water shortage and (2) water management and conservation methods to satisfy the unmet demand. One potential water management method is the construction of a new reservoir. The results of the research are aimed at helping to inform society and water managers about the potential changes in the water system. Based on this information, they might be able to introduce changes in their future plans to accommodate the predicted needs.

With an increasing demand for more complex and efficient structures, the world is in need of more structural engineers. I have been developing educational tools to make structural engineering more intuitive, tactile, and approachable. Using K’Nex, a readily available construction toy system, I build structures accompanied by computer models to illustrate key structural engineering principles. These products will aid in the education and promotion of structural engineering and are targeted towards children and undergraduates students. This research involves the investigating of physical properties of K’Nex members in order to create accurate numerical (computer) models. Experiments include load tests to determine material properties, buckling stresses, and failure modes. Many of these tests are designed to be approachable and can be performed using everyday household objects. Numerical models are created in MATLAB and are used to predict behaviors under certain load combinations, as well as highlight shortcomings of simplified elastic theory. The results and methodology of this research are designed to focus on building an intuition and interest for structural engineering.