Physical Sciences and Mathematics Commons^™

Precious Plastics - Plastic Brick Machine Fabrication, Timothy Ukaobasi Kanu, Evi Paraskevi Troulis

Architectural Engineering

The goal of this research is to determine the structural parameters of the recycled plastic polypropylene when molded into bricks resembling CMU blocks. To accomplish this, three mechanisms had to be assembled: the shredder, the injector, and the 1x1 mold. A tensile and compression test were to be performed on the plastic brick, and the values would be used to compare the tensile and compressive strength of PP plastic bricks, as well as their modulus of elasticity and stress vs. Strain performance. These values would be analyzed to determine whether it would be feasible to build an entire plastic wall. …

Microplastic Accumulation In Terrestrial Gastropods And Soils, Gregory B. Bonilla

Masters Theses

Microplastics (MPs) have become an emerging threat to ecosystems across the world. Transport, impacts, and fates are grossly understudied, especially in terrestrial environments. Current research on MP bioaccumulation has focused mainly on aquatic organisms with little study of terrestrial organisms, including snails where data are nearly nonexistent. To address this, we collected and examined land snails and their surrounding soil for MP content in shell and tissue. From September 11, 2020, to October 25, 2021, cover boards were placed (n=30) along relatively undisturbed sites in hardwood, forested areas, and tall grasses in a Wildlife Management Area (WMA) in Oak Ridge …

Big Business, Small Plastic, Hannah Johnson

Senior Honors Projects

No abstract provided.

Functionalized 𝜹-Hexalactones (Fdhls): Bio-Derivable Monomers To Synthesize Renewable Polyester Thermoplastics, Atik Faysal

Electronic Theses and Dissertations

Most thermoplastics are made from limited fossil-fuel sources and these plastics have very deleterious impacts on the environment. Finding a renewable source to synthesize new thermoplastic polymers with tunable properties like biodegradability, heat resistance, and moisture resistance are ongoing research interests. Lignocellulosic biomass is a promising renewable feedstock for biobased monomers and polymers production. In this work, functionalized 𝛿-hexalactone (FDHL) monomers are hypothesized to be synthesizable from lignocellulosic sourced hydroxymethyl furfural (HMF) and lignin-derived pendant groups, generating a variety of aliphatic polyesters and potentially overcome current polymer challenges. Achieving a higher glass transition temperature (T_g) is one of …

Soil Invertebrates In Agriculture: Assessing Ecosystem Services, Biodiversity Impacts, And Farmer Perceptions, Eva Kinnebrew

Graduate College Dissertations and Theses

Harmonizing biological diversity and crop production is a major goal towards building more sustainable food systems. Soil invertebrates are diverse and abundant organisms in agriculture, but relatively little is known about their benefits or how agricultural management impacts them. In this dissertation, I dig into the complex interactions between agricultural land use and soil invertebrate biodiversity to better inform farmer decision-making. I find that soil invertebrate communities have major potential contributions to agroecosystems (Chapter 2) and are shaped heavily by agricultural land use (Chapters 3, 4), but remain too uncertain to contribute to farmers’ management choices (Chapter 5). First, I …

Bacterial Biofilms Colonizing Plastics In Estuarine Waters, With An Emphasis On Vibrio Spp. And Their Antibacterial Resistance, Amanda L. Laverty, Sebastian Primke, Claudia Lorenz, Gunnar Gerdtz, Fred Dobbs

OES Faculty Publications

Since plastics degrade very slowly, they remain in the environment on much longer timescales than most natural organic substrates and provide a novel habitat for colonization by bacterial communities. The spectrum of relationships between plastics and bacteria, however, is little understood. The first objective of this study was to examine plastics as substrates for communities of Bacteria in estuarine surface waters. We used next-generation sequencing of the 16S rRNA gene to characterize communities from plastics collected in the field, and over the course of two colonization experiments, from biofilms that developed on plastic (low-density polyethylene, high-density polyethylene, polypropylene, polycarbonate, polystyrene) …

A Risk Analysis Of Microplastic Consumption In Filter Feeders, Sheri Rahman

HCNSO Student Capstones

Microplastics (plastic particles < 5 mm) pose a serious threat to marine organisms, as researchers have documented such particles in the gut contents of numerous species. In particular, filter feeders are at risk of consuming microplastics because they may accidentally consume the particulates when feeding or they may prey on species that have already consumed them. The goals of this research were to evaluate the risks that different filter feeders face in regards to microplastic consumption through the analysis of the calculated Microplastic Consumption Rates for numerous species of filter feeders. Factors that could potentially affect this risk were also considered, including ocean basin, environment type, salinity, life stage, IUCN status, and filtration technique. Initial analysis showed that body size greatly impacted a species’ risk of microplastic consumption and further tests were completed to evaluate overall microplastic contamination for each species. Microplastic consumption and microplastic contamination values were evaluated and analyzed to determine which filter feeding species were most at risk of experiencing ecological effects from microplastic pollution. From a resource management perspective, this research highlights the filter feeding species most at risk, contributing to the development of more effective plastic waste management policies.

Plastics And Microplastics As Vectors For Bacteria And Human Pathogens, Amanda Lee Laverty

OES Theses and Dissertations

Since plastics degrade very slowly, they remain in the environment on much longer timescales than most natural substrates and can thus provide a novel habitat for colonization by bacterial communities. The full spectrum of relationships between plastics and bacteria, however, is little understood. The objective of this study was to examine marine plastic pollution as a substrate for bacteria, with particular focus on Vibrio spp., including the human pathogens, Vibrio cholerae, Vibrio parahaemolyticus, and Vibrio vulnificus.

Colonization experiments were set up in a tributary of the lower Chesapeake Bay to follow Vibrio spp. colonization and …

Toward A Standard Trash Assessment Method, Sydney Harris

Salish Sea Ecosystem Conference

How much trash is carried from inland areas to the ocean? Where does hazardous solid waste accumulate once it has escaped into the environment? What are the most effective upstream interventions for waste reduction and the prevention of aquatic debris? These questions cannot be answered without reliable trash metrics. ORISE Research Participant Sydney Harris has worked with a national team of EPA staff to develop a standardized trash assessment protocol built upon existing methods including California’s Urban Rapid Trash Assessment, NOAA’s Shoreline Monitoring program, and others. This new tool will, for the first time, enable trash assessment in any environment …

Plastic As A Habitat For Bacteria And Human Pathogens. Subjects: Life Science / Biology Grades: 6-8, Amanda Laverty

Reports

This lesson plan invites 7th grade life science students to investigate marine plastic pollution as a habitat for bacteria and human pathogens. Students will examine the hazards of marine plastic pollution and learn about current science. They will have the opportunity to use data to create graphs and discuss patterns.

Influence Of A Suite Of Environmentally Relevant Conditions On Pbt Leaching From, And Sorption To, Marine Microplastic Debris, Robert C. Hale, Da Chen

Reports

Synthetic polymers (plastics) enter marine environments from terrestrial and marine-based sources. The manner of release, the plastic’s composition/properties and ambient marine conditions determine debris fate and its impacts on living resources. It was long assumed that all plastics were persistent and inert, possessing negligible potential for chemical impacts. However, in reality, commercial polymers exhibit a range of potentials for interactions. Persistent, bioaccumulative and toxic (PBT) chemicals are lipophilic and may concentrate from ambient waters by orders of magnitude on polymer surfaces (Teuten et al., 2007). The type of polymer affects the degree of PBT sorption. Indeed, plastics have been found …

Anthropogenic Particles In Natural Sediment Sinks: Microplastics Accumulation In Tributary, Beach And Lake Bottom Sediments Of Lake Ontario, North America, Anika M. Ballent

Electronic Thesis and Dissertation Repository

Surface waters of the Great Lakes are known to be contaminated with microplastics, however, microplastics in the sediments of the region are poorly documented. This study provides a baseline of micro- and macro-plastics contamination in nearshore, tributary and beach sediments of Lake Ontario and the upper St. Lawrence River. Microplastics were quantified and characterized by morphology and composition using visual identification and Raman spectroscopy. Microplastics are most concentrated in nearshore sediments in the vicinity of urban and industrial regions. Concentrations in Humber Bay and Toronto Harbour consistently measured > 500 particles per kg dry sediment, and maximum concentrations of ~28,000 particles …

Improving The Engineering Properties Of Pla For 3d Printing And Beyond, Carmen R. Rocha

Open Access Theses & Dissertations

Additive manufacturing (AM), now more commonly known as 3D printing, has been classified as efficient, fast, and practical in the prototyping sector of product development. In the work presented here, we will use one of the AM techniques known as Material extrusion 3D printing (ME3DP), which has all the advantages of AM. However, one of the biggest challenges facing ME3DP technologies is the limitation of the range of materials used by this technique. Acrylonitrile butadiene styrene (ABS) and poly-lactic acid (PLA) are currently the most common thermoplastics materials used in ME3DP because of their ability to melt and be reprocessed. …

Cetaceans And Marine Debris: The Great Unknown, Mark Peter Simmonds

Mark P. Simmonds, OBE

Plastics and other marine debris have been found in the gastrointestinal tracts of cetaceans, including instances where large quantities of material have been found that are likely to cause impairment to digestive processes and other examples, where other morbidity and even death have resulted. In some instances, debris may have been ingested as a result of the stranding process and, in others, it may have been ingested when feeding. Those species that are suction or “ram” feeders may be most at risk. There is also evidence of entanglement of cetaceans in marine debris. However, it is usually difficult to distinguish …

Multiple Transient Memories In Experiments On Sheared Non-Brownian Suspensions, Joseph Paulsen, Nathan C. Keim, Sidney R. Nagel

Physics - All Scholarship

A system with multiple transient memories can remember a set of inputs but subsequently forgets almost all of them, even as they are continually applied. If noise is added, the system can store all memories indefinitely. The phenomenon has recently been predicted for cyclically sheared non-Brownian suspensions. Here we present experiments on such suspensions, finding behavior consistent with multiple transient memories and showing how memories can be stabilized by noise.

Degradable Plastics And Solid Waste Management Systems, David J. Tonjes, Krista L. Thyberg

Technology & Society Faculty Publications

Plastics, which are woven into the fabric of modern life, have consequential impacts on the environment. Many of these are associated with end-of-lifetime processes, and include chemical contamination of the environment and effects from litter. Plastics also complicate waste management processes, causing contamination in composting operations, and having poor recovery rates through recycling. Plastics that are not as biologically recalcitrant, that decompose when use is done, have been perceived as solutions to at least some of these problems. The first generation of degradable plastics did not meet marketing claims; some of the more recent formulations, partly as a consequence of …

Comparison Of The Fuel Needed To Transport Plastic Recyclables Verses Aluminum Recyclables From Yellowstone National Park, Melissa Dejonge

Department of Environmental Studies: Undergraduate Student Theses

Research has provided no definitive answers on whether PET plastic bottles or aluminum cans are a more environmentally sustainable choice as soda containers. This paper researches the fuel used in recycling each of these materials from Yellowstone National Park to processing locations. The data is used to determine which of these alternatives use less fuel in this process. It was found that plastics use more fuel when transported from Yellowstone National Park to the processing center. Aluminum uses less fuel per ton to transport from Yellowstone to the processing center. The conclusions from this research may have implications on which …