Browsing by Subject "Packaging"
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Item Artificial intelligence : a critique of our plastic consumption(2022-05-07) Diamos, Vanessa Zaragoza; Gorman, Carma; Lavigne, Sam (Samuel); Schell, JulieIn this modern age of convenience, we interact with many different types of plastic every day, including microplastics. Microplastics are tiny particles of broken-down plastic. A recent study suggests that people ingest about a credit card’s worth of microplastics each week, which doesn’t even include microplastic exposure through inhalation and direct skin contact. By design, most consumers are unaware of the reproductive, digestive, respiratory, nervous, immune, and environmental impacts of plastic production and packaging. In addition, the labeling on plastic packages is misleading: the recycling logos on the bottom imply consumers can recycle them, which rarely happens, and there are no federal regulations mandating that companies disclose the level of microplastic contamination in their products. These labeling problems prevent consumers from making informed decisions about whether to buy a product packaged in plastic. I suggest ways to remedy these labeling problems through graphic design to educate consumers about the extent of microplastic contamination in the products they buy. These proposed labels reveal the hidden dangers of microplastics on human health, animal health, and the environment while providing accurate information about the packaging’s recyclability and proper disposal.Item Deliver me from waste : impacts of e-commerce on food supply chain energy use(2019-05-09) Gee, Isabella Marie; Webber, Michael E., 1971-; Apte, Joshua; Lieberknecht, Katherine; Allen, David; Faust, KaseyAn increasing portion of food is purchased online through e-commerce services such as meal-kit and grocery delivery. As these services change the way food is purchased and distributed, they also impact how energy is used along the food supply chain. Impacts will differ based on type of service, location, and consumer habits. In particular, meal-kit and grocery delivery services might impact consumer food waste, packaging waste, and energy consumption for transportation related to deliveries. This research attempts to assess the potential impact of food delivery services to energy use along the entire food supply chain, accounting for food loss and waste. An analytical model was developed to compare the energy requirements of meal-kit delivery systems to conventional grocery shopping. Meal-kit services can reduce food waste because the kits pre-portion ingredients for each recipe, thereby saving energy. However, the supply chain and packaging requirements of meal-kit delivery are different than for grocery stores, potentially offsetting any reduction of food waste. Furthermore, if meal-kit delivery replaces some trips to the grocery store, then transportation-related savings might be significant. Mass and energy balances were used to assess embedded energy in both pathways. The model was illustrated under representative operating conditions for a consumer in Austin, Texas using Monte Carlo simulation. Both per-meal and per-week, a meal-kit delivery service meal is more energy intensive than procuring the same meal from conventional grocery stores primarily due to single-use packaging. Consumer transportation to the grocery store was also found to be particularly energy intensive. Results also indicated that there might be a greater potential to reduce energy use when consumers live further from a grocery store. A second analytical model was developed to compare the energy requirements of grocery delivery services to grocery shopping. Two types of grocery delivery services were considered: decentralized (store-centric) and centralized (warehouse-centric). The supply chains for both store- and warehouse-centric grocery delivery services also differ from conventional grocery shopping, and might offset changes in food waste. Store-centric grocery delivery services primarily affect last-mile transportation by replacing a personal trip with a delivery, though they might be able to reduce energy by bundling multiple orders together in one trip. Warehouse-centric grocery delivery services might have a greater impact on energy use because they set up their own separate supply chain with primary fulfillment centers and delivery vehicles. Mass and energy balances were used to assess embedded energy per-week in both pathways. The model was illustrated under two consumer case studies using Monte Carlo simulation. In both cases, the warehouse-centric grocery delivery service was the least energy intensive. The store-centric grocery delivery service showed slight energy savings. Results suggest that consumer transportation and retail energy use are the two major contributing factors to relative energy intensity between scenarios. Results also indicated that grocery delivery services might be able to save more energy for consumers that live further away from a grocery store. For all food purchase pathways analyzed, consumer last-mile transportation (the last leg of the supply chain before food reaches a consumer) was found to be particularly energy intensive. Additionally, results suggested that food delivery services might be able to save more energy for rural consumers. To build off of these findings, a hybrid agent-based and discrete-event simulation modelling framework was developed to capture the last-mile transportation energy use of food delivery services for rural consumers. The framework operates in a geographic information system (GIS) space and tracks per-trip energy use of a delivery van and delivery car operating in a sample neighborhood in west Austin, TX. A sensitivity analysis was performed to gauge the impact of vehicle speed and number of orders fulfilled on per-trip energy use. In general, the delivery van trip was always more energy intensive than the delivery car over the range of values studied. However, results indicated that there is a theoretical threshold based on consumer demand and density that dictates when van- or car-based delivery is energetically preferable. Taken together, this body of work provides methods for evaluating the farm-to-fork energy impacts of food delivery services, with particular attention to last-mile transportation.Item Oxygen scavenging styrene-butadiene-styrene block copolymer films for barrier applications(2013-08) Tung, Kevin; Paul, Donald R.; Freeman, B. D. (Benny D.)This dissertation discusses the oxidation behavior of reactive membranes that were produced by solution casting and by melt extrusion. These films, containing styrene-butadiene-styrene (SBS) block copolymer that undergoes catalytic oxidation, are of potential use as an oxygen scavenging polymer (OSP) for barrier applications. A thin film kinetic model was developed to ascertain reaction parameters that were used to describe thick film oxidation behavior. Ultimately complex structures containing these scavengers need to be produced via melt-extrusion. Therefore, processing conditions were established to ensure that melt-processed films have the same oxidation kinetics and capacity as those prepared by solution casting. Blends containing a non-reactive styrene phase and an oxygen-scavenging SBS phase were extruded and, by uptake and permeation experiments, their oxidation behaviors were monitored. The flux behavior and time lag extension as a function of oxygen pressure, film thickness, SBS scavenger and photoinitator contents were measured and compared to the theoretical model. The permeation behavior of the reactive blend films containing SBS showed that time lags can be extended via an oxidative mechanism and barrier properties be improved compared to traditional packaging membrane of native polystyrene.Item Photocrosslinkable nonlinear optical polymers and directly-patternable polyimide dielectrics(2014-08) Bell, William Kenneth, III; Willson, C. G. (C. Grant), 1939-; Ellison, Christopher; Anslyn, Eric; Ho, Paul; Keatinge-Clay, Adrian; Rose, MichaelThe development of high-efficiency nonlinear optical (NLO) polymers has opened up many opportunities in the field of electro-optics. However, current NLO polymers do not meet stability requirements for semiconductor integration. In an effort to improve this, we examined the effects of crosslinking following electric field poling. A series of photocrosslinkable polymers bearing side chain chromophores was synthesized, poled and evaluated on the basis of the thermal stability of Second Harmonic Generation. Photoinitiation allowed for control of the onset of curing. Crosslinking was monitored by FTIR and optimal conversion was achieved by applying a slow temperature ramp during exposure. The ultimate stability of the poled polymers was directly related to the number of crosslinking substituents attached to the chromophore pendant group. With two reactive groups per chromophore significant SHG was retained at temperatures beyond the polymer Tg. In integrated circuit packaging there is a need for directly-patternable polymers of low dielectric constant. Bridging the gap between the high-value silicon chip and circuit board is a substrate comprising alternating layers of metal conductor and polymer dielectric. PMDA-ODA, an aromatic polyimide, meets many of the requirements for integration and can be patterned using a photobase generator (PBG). Due to absorbance by the PMDA-ODA precursor, this PBG must have activity at visible wavelengths. Several oxime urethanes were synthesized and evaluated as candidate long wavelength PBG. These compounds exhibit clean photochemistry and high visible light sensitivity. Unfortunately, carbamate thermal stability is insufficient for patterning PMDA-ODA. For improved material properties, PMDA-TFMB, a fluorinated polyimide, was also evaluated. Importantly, the polymer precursor is sufficiently transparent to employ thermally-stable near-UV photobases. With photobase, 2.5 micron features were resolved in PMDA-TFMB. An ancillary benefit of this methodology is reduced cure temperature (~200 °C), a traditional drawback of polyimides. This material demonstrates a dielectric constant near 3 and a thermal expansion coefficient (CTE) of approximately 6 ppm/°C in-plane. Through-plane thermal expansion is somewhat problematic, with a CTE of approximately 160 ppm/°C, and will likely require a nanoparticle composite strategy. However, this combination of material and lithographic properties make PMDA-TFMB a promising candidate for this application.