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The contrail-correlated solar irradiance data was analyzed by calculating the magnitude of the irradiance drop for each contrail within specified sun-to-contrail configurations on a clear day. Results showed that contrail dissipation rates are significant factors in understanding the effects of contrails in general. Dissipative contrails affect DNI in a similar extent to that of cloud cover over a multi-minute time interval, while nondissipative contrails produce sharp drops in DNI over time intervals of 2 minutes or less. On a clear day, dissipative and nondissipative contrails can cause drops in DNI of greater than 500 W/m2 and 150 W/m2, respectively. These results show that contrails should be considered in both solar power plant site selection and power output forecasting.
KINETICS OF BISPHENOL A AND 17 Β-ESTRADIOL OXIDATION BY MANGANESE (IV) OXIDESBillionrosannae Chhouk1, Jacqueline Meija2, Matthew Ginder-Vogel2, Christina Remucal2.
San Diego State University, San Diego, CA, 2University of Wisconsin-Madison, Madison, WI.
1 The endocrine system refers to the complex network of hormones and receptors responsible for maintaining normal nervous and reproductive system development among many other biological processes in all organisms.
Unfortunately, many synthetic compounds, termed endocrine disruptors, can mimic or block these hormones and negatively affect the organism involved. At low concentrations, endocrine disruptors are known to alter normal cellular development and cause the feminization of fish populations. This project investigates the ability of manganese oxide to degrade 2 ubiquitous endocrine disruptors found commonly in the environment: bisphenol A (BPA) and 17 β-estradiol (E2). BPA is used in plastic production, and E2 is an estrogen used in contraceptives. Previous studies have shown that manganese oxides can oxidize a wide range of organic pollutants due to their large surface areas (from 2 to 260 m2g-1) and high redox potentials. However, researchers have failed to assess the changes in the mineral surface and have not been able to identify the oxidation reaction products. This project has two main objectives: use X-ray absorption spectroscopy to identify the mineralogical transformations of manganese oxides and study the oxidation rates of BPA and E2 via high performance liquid chromotrography. The oxidation rates will be evaluated under various conditions including pH, salt concentrations, and dissolved organic matter concentrations.
This project will provide a novel understanding of how manganese oxides can be used to detoxify and remove harmful endocrine-disrupting compounds in controlled waste-water treatment facilities to ultimately promote the health of humans and wildlife.
INDOOR AND OUTDOOR AIR QUALITY IN THE LATINO COMMUNITY IN BOULDER, COLORADOLuis Escobedo1, Lupita Montoya2.
Baylor University, Waco, TX, 2University of Colorado Boulder, Boulder, CO.
1 The Environmental Protection Agency has established methods and metrics for qualifying and regulating outdoor air quality; however, indoor air quality (IAQ) has not enjoyed the same level of attention. In fact, indoor levels of many pollutants are often several times higher than levels found outdoors. Indoor air pollutants can concentrate due to poor circulation within a home. Further, Americans spend most of their time indoors where they can experience exposures that may result in poor respiratory and cardiovascular health. This investigation targeted a low-income Latino community in Boulder, Colorado, and focused on the indoor air quality of their homes as well as the ambient (outdoor) air in their area. Participants were administered a survey that included questions on their health conditions and indoor air pollution sources (e.g., cigarette smoke, combusted fuel used for heat, and building materials). In addition, the indoor and outdoor air in each home was sampled for a period of 24 hours using tactical air samplers (MiniVol Airmetrics, Eugene, OR). Air samples were collected onto 2 different filters (47 mm teflon and Tissuquartz) to measure the quality of the air. The teflon filters were analyzed gravimetrically to measure PM2.5 (particulate matter of diameter
2.5 micrometers and below) and tested for the presence of endotoxins and proteins in the air. The Tissuquartz were analyzed for elemental and organic carbon. Early results indicated that the indoor air contained a higher concentration of pollutants than the ambient air and that there were measurable levels of endotoxins on most air samples.
VALORIZATION OF DISTILLERS DRIED GRAIN THROUGH ACID HYDROLYSIS AND ALKALINE EXTRACTIONJamison Watson1, Troy Runge2, Zhouyang Xiang2.
St. Olaf College, Northfield, MN, 2University of Wisconsin-Madison, Madison, WI.
1 Due to the cessation of ethanol subsidies, a need has arisen to increase the vitality of ethanol production through the valorization of distillers dried grain (DDG). DDG, the primary by-product of ethanol production, is primarily sold as animal feed for modest revenue. However, higher value products can be extracted from DDG. DDG is composed primarily of protein and fiber. Hemicellulose is a primary fiber found in DDG that animals cannot digest. This study proposes 2 mechanisms to extract the indigestible hemicellulose in animal feed and to convert it to green alternative products. Thus, the purpose of this study is twofold: convert hemicellulose monomers to furfural from DDG, and extract hemicellulose polymers from DDG to create a paper film. Aqueous solutions of furfural were produced from DDG hydrolysate using batch dehydration procedures. Results indicate that optimal conditions occur at 180 °C and 1% acid. Separately, solid hemicellulose polymers were extracted from DDG through treatment with alkali media followed by ethanol precipitation. The polymer was then casted as a film. Current testing is being performed to determine the polymer’s effectiveness as a paper film. Furfural and hemicellulose polymers produce revenues up to $0.70 and $2.00 per pound, respectively. In contrast, DDG produces only $0.15 per pound as feedstock. Furfural yields are currently too low to permit a significant revenue gain; however, optimization is currently being performed to maximize yield and lower reaction conditions. Furthermore, the hemicellulose film shows great promise with respect to revenue gains depending on its mechanical properties.
CURRENT STATUS AND PROSPECT OF RENEWABLE ENERGY STORAGE TECHNOLOGIESYisi Li, George Tynan.
University of California, San Diego, La Jolla, CA.
With the common goal of creating a more sustainable living global environment, scientists and engineers around the globe have been working on improving current and creating new methods to produce renewable energies. With the increasing production of renewable energy resources, there is also a drastic and increasing demand for higher energy storage capacities in order to meet public demand and also to maintain power quality and availability. In this project, we will provide an overview and introduction of current energy storage technologies which can be divided into 3 main categories: electrochemical energy storage, mechanical energy storage, and thermal energy storage. We will also describe the existing popular methods developed in each category. The pros and cons of each method will be analyzed in detail, followed with comparison between these methods. We will also look at the potential of future energy storage technologies to provide significant improvements over current technologies.
DEVELOPING WOOD PLASTIC COMPOSITES AS SUSTAINABLE COMMODITIES USING RECYCLEDMATERIALS Fernando Perez, Delia Valles.
New Mexico State University, Las Cruces, NM.
Waste management is a major issue in the agricultural industry. With waste management being a major industry in the Southwest, much interest is being developed in uses for the agricultural waste produced by these processes.
In this study, the authors have produced and investigated a new composite material conception based on recycled polyethylene (rPE) and wood particles obtained from agricultural waste, specifically the stalks and leaves of chili Engineering plants. The study shows a comparative analysis of grain size of wood particles versus percentage of materials and the resulting effect these variables have on the composite material when introduced to mechanical stresses. The new composite mixture was analyzed by means of statistical analysis and scanning electron microscopy (SEM) analysis.
Preliminary results found that grain size and percentage of raw material affect the composite material’s performance of ultimate tensile strength and yield point when introduced to mechanical stresses.
OPTIMIZING DISASSEMBLY OF PRINTED CIRCUIT BOARDS USING A SUPERCRITICAL CARBON DIOXIDEPROCESS Felipe Silva, John Carrell.
Texas Tech University, Lubbock, TX.
Printed circuit boards (PCBs) are complex components present in a large variety of electronic devices. Although PCBs have well defined manufacturing technologies, the disassembly and recycling process for these devices still represents a challenge. The purpose of this work is to analyze and optimize the disassembly process of PCBs using a supercritical carbon dioxide process. An experimental design was conducted using 4 control factors each with 3 levels. The factors included temperature (160 °C, 190 °C, and 220°C), pressure (1500 psi, 3500 psi, and 5500 psi), solvent used in reaction (pure carbon dioxide, water mixture, and sodium carbonate mixture), and vessel depressurization (every 4 hours, 1 hour, and ½ hour). From performed experiments, the supercritical carbon dioxide process has been validated as providing an environmentally benign solution for disassembling PCBs for recycling.
The conducted experiments have provided key effects based on tested control factors for the supercritical carbon dioxide process. Based on these effects, the optimal disassembly and recycling scenario for the super critical carbon dioxide process is with high operating pressures, high temperatures, frequent depressurizations, and the sodium carbonate mixture solvent. This optimal process showed the greatest weight reduction and thickness increase of the PCB denoting the best delamination of the PCB for disassembly and recycling.
MATERIALS ENGINEERING (INCLUDING CERAMICS/TEXTILES)
CHARACTERIZATION OF INDIUM GALLIUM ARSENIDE THERMOELECTRIC MATERIALS GROWN BY
CHEMICAL BEAM EPITAXY AND DOPED WITH RARE EARTH NANOPARTICLESVishaal Varahamurthy, Ryan Need, Christopher Palmstrøm.
University of California, Santa Barbara, Santa Barbara, CA.
The thermoelectric effect can play a significant role in the global effort to improve energy efficiency by converting waste heat from automobiles, households, and industrial electronics into usable electricity. Prior research has shown indium gallium arsenide (InGaAs) to be a highly effective thermoelectric material. In this study, we will characterize InGaAs materials grown by chemical beam epitaxy and doped with rare earth elements (e.g., erbium and lanthanum).
In small amounts, these rare earth dopants affect the efficiency of the thermoelectric material by changing the carrier concentration. In larger quantities, the rare earths precipitate out of the matrix and form nanoparticles, which in theory can further improve device performance by reducing thermal conductivity. We will vary growth parameters such as dopant concentration, growth temperature, and background chamber pressure, and measure their resulting effects on electrical properties and thermoelectric performance using the Hall and Seebeck techniques. We predict that the
195 UNDERGRADUATE POSTER ABSTRACTS
identity of the rare earth dopant will have a minor effect on the electrical characteristics of the material because the solubility of the rare earth elements in InGaAs is low and the ionization energies of the different dopants are similar.
However, the varied growth conditions should have a more significant impact on thermoelectric performance through their effects on the formation, size, and distribution of the rare earth nanoparticles that precipitate during growth.
By observing how these growth parameters affect the material’s thermoelectric performance, we can expand our knowledge of the thermoelectric effect and facilitate research that will lead to improved energy efficiency.
HIGH SENSITIVITY TERAHERTZ METAMATERIAL SENSORErik Bautista1, Azucena Yzquierdo1, Dragoslav Grbovic2.
Hartnell College, Salinas, CA, 2Naval Post Graduate School, Monterey, CA.