Hiller Measurements requested a mechanical design process to produce the internal chassis of their customized aerospace test equipment. The 3D printing team explored additive manufacturing to produce the generatively designed chassis using an MSLA 3D printer and photopolymer resin. The team improved production quality by standardizing support, raft, and print speed settings. Troubleshooting common 3D printing errors included reducing the effects of elephant’s foot, minimizing peeling forces, and adjusting FEP film tightness. Post-processing involved exploring the effect of cure time on material performance by utilizing dynamic vibration testing and tensile & compression testing. Final assessments were made by considering the ease of assembly of all parts and holders. 3D printing was determined to be an effective tool for production when the parts are designed for manufacturing and when the material properties are in accordance with its desired functionality. 

The reduction of CO2 emissions and the avoidance of Global Climate Change necessitate the conversion of the electricity generation industry to rely on non-carbon sources. Additionally, the mitigation of the duck-curve effects in microgrids requires the development of grid-independent buildings. Computations were performed for a cluster of one thousand grid-independent buildings in the North Texas area, where air-conditioning demand is high in the summer months. The electricity demand is balanced with energy supply generated from wind turbines, photovoltaic cells, or stored energy in hydrogen tanks. The results indicate that with one wind turbine operating, each building must be fitted with 10.2 kW rating photovoltaics capacity and a tank with 5.2 m3 of hydrogen storage capacity to satisfy the hourly demand of the buildings’ community. The addition of more wind turbines significantly reduces the needed PV rating but increases the required storage. Investing in energy conservation measures in the buildings significantly reduces both the needed storage capacity and the PV cell ratings.

The overall purpose of this project is to create a process for designing and manufacturing a Chassis (Mechanical Enclosure) for Hiller Measurements. As the Industrial Optimization sub-team, we focused on ways to optimize and fully document the process. The goal was to create procedures for utilizing 3-D generative design and printing software that most adults would be able to follow. Outside TCU students with little to no engineering background were brought in to test our procedures.

Trees provide essential ecosystem services to urban environments. Urban forests attenuate air pollution, mitigate flooding, reduce energy consumption, raise property values, promote community cohesion, and enhance quality of life. To maximize these services, colleges, universities, and associated campus organizations engage in a host of activities designed to enhance the structure and function of their urban forests. These activities include protecting and preserving trees, planting and maintaining trees, and offering outreach on the benefits of trees. Additionally, tree measurements present an opportunity to assess the extent to which campus trees provide important services to the university and the surrounding community. The purpose of this research is to quantify the ecosystem services of trees on the TCU campus. We recorded standard tree measurement variables, including trunk diameter, tree height, and crown width. Next, we used i-Tree Eco, an open source urban forestry software from the USDA Forest Service, to quantify the ecosystem services of campus trees. We calculated the following services: 1) pollution removal and human health impacts; 2) carbon sequestration and storage; and 3) hydrology effects, including avoided run-off, interception, and transpiration. Preliminary results indicate that campus trees provide a range of ecosystem services but vary by species and location. We recommend continued maintenance of campus trees and additional tree plantings to maximize ecosystem services.

Long-jawed orbweaving spiders (Tetragnatha sp.) as Sentinels of Mercury Contamination of the Trinity River

Authors: Tori Martinez, Macyn Willingham, Christopher Allender, Morgan Capone, Matt Chumchal, Ray Drenner, Cale Perry, Robby Peterson, Iris Schmeder, Andrew Todd, Tyler Williams

Human-made sources such as coal-fired power plants and artisanal gold mines have large outputs of emissions containing inorganic mercury (IHg), resulting in an overall increase in environmental mercury (Hg) levels across the globe. IHg is not bioavailable and therefore does not normally pose a risk to organisms. However, the conversion of IHg to bioavailable methylmercury (MeHg) that takes place in an aquatic ecosystem threatens human and wildlife health, given that MeHg is a neurotoxin. To investigate this further, the amount of MeHg must be determined for specific locations given that there is a large variation in inorganic mercury deposition throughout various landscapes and ecosystems. Specifically, this project examines the bioaccumulation of MeHg in aquatic food webs and individual bodies of water, through the use of shoreline spiders as a sentinel species. If excess mercury is present within an aquatic food web, there would be a presence of mercury in emergent aquatic insects. Shoreline spiders, then, prey on the emergent aquatic insects, resulting in an accumulation of mercury within their tissue. Shoreline spiders have been proposed as sentinels of MeHg but there have been relatively few studies examining biological factors that could influence the concentration of MeHg in their tissues. The objective of this study is to determine how spider size and sex can influence MeHg concentrations in the Clear and West Fork of the Trinity River. There is existing evidence that the two forks may have varying amounts of mercury accumulation, based on a study done in 2016. This study focused on the long-jawed orb weaver (Family Tetragnathidae; Tetragnatha sp.) shoreline spider, in which over 1000 were captured from June to August 2019. We preserved spiders in 95% ethanol followed by measurement of leg length (a proxy for body size), determination of spider sex and Hg analysis. In this presentation we will discuss the relationship between spider size, sex, and ecosystem contamination levels on Hg concentration.