Browsing by Subject "Department of Bioproducts and Biosystems Engineering"

Now showing 1 - 14 of 14
  • Thumbnail Image
    Item
    Altering Variables in the Half-Reaction for the Synthesis of Selenium Nanoparticles on Supports
    (2019) Wheeler, Samantha; Brockgreitens, John; Ahmed, Snober; Abbas, Abdennour
  • Thumbnail Image
    Item
  • Thumbnail Image
    Item
    Biobased Pressure-Sensitive Adhesives
    (2010) Roerdink Lander, Monique; Zhang, Jiguang; Houtman, Carl J.; Severtson, Steven J.
    Pressure sensitive adhesive (PSA) products have become ubiquitous in our homes and offices through address labels, stamps, sticky notes, and tapes. The majority of these PSAs are based on petroleum-derived acrylates. In 2006, more than 300 million dry pounds of acrylic adhesive was sold in the United States. Incorporation of biomass-derived resources as a substitute for acrylates will make a significant contribution in the development of sustainable products. We developed PSAs with high biomass-content using biomass-based macromonomers, which can copolymerize with standard adhesive acrylates and replace 40-60% of petroleum-based raw materials. The work described here is an example of a novel, yet pragmatic approach to develop sustainable PSA formulations by simple modifications of successful commercial products, while maintaining performance.
  • Thumbnail Image
    Item
    Development of a Solar Smoleniec/Stirling Hybrid Thermo-Mechanical Generator
    (2010) Goldberg, Louise F.
    The Thermo-Mechanical Generator was invented in 1967 and is an ingeniously simple and elegant heat engine operating on a Stirling thermodynamic cycle that can yield cogenerated electrical and thermal energy from moderately hot heat sources (200-500°C). A new version of this heat engine has been invented that is capable of operating off concentrated solar energy provided by inexpensive, acrylic Fresnel lenses. A key innovation in the technology is the use of a digital thermodynamic Smoleniec/Stirling cycle to optimize the performance of the heat engine in real time. A state space analysis of the engine has been completed that demonstrates that the invention can operate successfully. So far, the analysis has predicted an output electrical power of 1.9 kW when operating between hot and cold temperature limits of 500 C and 20 C respectively. Under these conditions the engine operates at a frequency of 87 Hz.
  • Thumbnail Image
    Item
    Effect of the Addition of Clay and Wetting/Drying Cycles to the Contaminated Soils at the National Crude Oil Spill Fate and Natural Attenuation Research Site (NCOSFNARS)
    (2012-04-18) Wendt, Bryan
    Although thirty-three years have passed since the 1979 pipeline break at the NCOSFNARS near Bemidji, Minnesota the soil within the zone sprayed by pipeline oil exhibits strong signs of oil contamination. The soils found within the spray zone are water repellent due to this contamination, and in result affects the growth of non-woody and woody vegetation. In the pursuit of providing alleviation techniques for oil-contaminated soils, a study has been initiated to evaluate the effectiveness of clay addition to alleviate soil hydrophobicity. This will be done by first conducting particle size distributions of the soil. Secondly, clay will be added at various rates and water repellency will be tested for using the molarity of ethanol (MED) test and water drop penetration time (WDPT) test. Lastly, wetting/drying cycles will be imposed on the sample and retested for water repellency.
  • Thumbnail Image
    Item
    Exploiting the Fungal Species to Remediate the “Forever” PFAS Contaminants
    (2022) Nguyen, Sam
    PFAS (per- and polyfluoroalkyl substances) are artificial chemicals that have caused increased environmental concerns due to their highly stable and resistant chemical properties. This project aimed to determine which fungal species could effectively tolerate and remediate perfluorooctanoic acid (PFOA), a type of PFAS. Six wood-decaying fungal species were inoculated in liquid media with the addition of PFOA. These cultures were monitored for six weeks. It was observed that F1* and F2* had the highest fluoride concentrations after the testing period, suggesting high biological degradation and defluorination potential among these fungal species. *Because this is an ongoing project, the scientific names of the species were replaced.
  • Thumbnail Image
    Item
  • Thumbnail Image
    Item
    Investigating the Water Quality Impacts of Floating Treatment Wetlands in a Stormwater Retention Pond and Lake: An Environmental Monitoring Approach
    (2019) Oddsson, Mattias
    Floating treatment wetlands (FTWs) are a best management practice (BMP) applied in aquatic environments to improve water quality by mitigating nutrient pollution. This paper evaluates the efficacy of FTWs installed in natural environments as a tool for the removal of excess nutrients and enhancement of water quality. To this end, regular measurements of key water quality indicators as well as qualitative observations were made at two sites in Minnesota where FTWs have been installed. The results show that there were measurable changes in several water quality parameters over the study period. Statistically significant changes were observed in ortho-phosphate concentration, dissolved oxygen concentration, and pH for one of the study sites. Changes observed in other parameters were inconclusive, and further work is required to understand how FTWs may affect water quality in natural environments when deployed at low coverage rates, as well as how much of the observed changes are attributable to the FTWs and to natural changes in the environment.
  • Thumbnail Image
    Item
    Mass Production of Algae to Make Biodiesel
    (2008-10-02) Biorn, Steven A.
    The purpose of the project is to isolate a species of algae with large quantities of triacylglycerides, starch and biomass. The Ruan Laboratory at the University of Minnesota has isolated several species of algae from Minnesota’s ponds, rivers and lakes. Variations in CO2 quantity, and how it affects algae growth were also investigated.
  • Thumbnail Image
    Item
    Measurement of Diamagnetism in Water
    (2010-04-21) Chen, Zijun
    Diamagnetic materials create magnetic fields that opposes an externally applied magnetic field. Water is a diamagnetic material. However, the interaction is extremely weak, and visually noticeable effects can only be obtained using powerful superconducting magnets. In the past, demonstrations of diamagnetism in water using more accessible permanent magnets have been qualitative. The goal of the experiment was to quantify the diamagnetic effect of a permanent magnet on water using techniques accessible at a high school or introductory college physics level.
  • Thumbnail Image
    Item
    Roll Press Compaction of Corn Stover and Perennial Grasses
    (2011-11) Kaliyan, Nalladurai; Morey, Vance; Schmidt, David; Tiffany, Douglas
    Increasing the bulk density of biomass materials to at least 240 kg/m3 (15 lb/ft3) is important for efficient handling and truck transport from the field to an end user. Roll press compaction increased the bulk density of coarsely ground biomass materials to 265 to 365 kg/m3 (16 to 23 lb/ft3).
  • Thumbnail Image
    Item
  • Thumbnail Image
    Item
    Solubilization of Potassium and Phosphorus via Fungi
    (2022) Lindemann, Claire; Sun, Xiao; Hu, Bo
  • Thumbnail Image
    Item
    Stimulation of Nisin Production from Whey by a Mixed Culture of Lactococcus lactis and Saccharomyces cerevisiae
    (2012-04-18) Syed Mohd Nasir, Sharifah Natasha Aqilah
    L.lactis, a Gram-positive bacterium, grows on lactose or milk sugar and produces lactic acid as a byproduct. L.lactis also generates a non-toxic and antibacterial chemical called nisin which is often used as a natural food preservative. Therefore, a continuous growth of L.lactis is often desirable to increase the production of nisin. However, lactic acid accumulation lowers the pH of fermentation broth thus creates a non-sustainable environment for the growth of L.lactis. This research project aims to create a stress-free growth environment for L.lactis via in-situ removal of lactic acid. Saccharomyces cerevisiae or generally known as Baker’s yeast is used to consume lactic acid as a carbon source for metabolism activity.