As byproducts generated by commercial and domestic food-related processes, FOGs (fats, oils, and grease) are the leading cause of sewer pipe blockages in the US and around the world. Grease trap waste (GTW) is a subcategory of FOG currently disposed of as waste, resulting in an economic burden for GTW generators and handlers. This presents a global need for both resource conservation and carbon footprint reduction, particularly through increased waste upcycling. Therefore, it is critical to better understand current GTW handling practices in the context of the urban food–energy–water cycle. This can be accomplished with firsthand data collection, such as onsite visits, phone discussions, and targeted questionnaires. GTW disposal methods were found to be regional and correspond to key geographical locations, with landfill operations mostly practiced in the Midwest regions, incineration mainly in the Northeast and Mid-Atlantic regions, and digestion mainly in the West of the US. Select GTW samples were analyzed to evaluate their potential reuse as low-cost feedstocks for biodiesel or renewable diesel, which are alternatives to petroleum diesel fuels. Various GTW lipid extraction technologies have been reviewed, and more studies were found on converting GTW into biodiesel rather than renewable diesel. The challenges for these two pathways are the high sulfur content in biodiesel and the metal contents in renewable diesel, respectively. GTW lipid extraction technologies should overcome these issues while producing minimum-viable products with higher market values.

The development of new flexible and lightweight electronics has increased the demand for compatible energy storage devices to power them. Carbon nanotube (CNT) fibers have long been known for their ability to be assembled into yarns, offering their integration into electronic devices. They are hindered, however, by their low intrinsic energy storage properties. Herein, we report a novel composite yarn, synthesized through solvothermal processes, that attained energy densities in the range between 0.17 µWh/cm² and 3.06 µWh/cm², and power densities between 0.26 mW/cm² and 0.97 mW/cm², when assembled in a supercapacitor with a PVDF-EMIMBF4 electrolyte. The created unique composition of iron oxalate + iron hydroxide + CNT as an anode worked well in synergy with the much-studied PANI + CNT cathode, resulting in a highly stable yarn energy storage device that maintained 96.76% of its energy density after 4000 cycles. This device showed no observable change in performance under stress/bend tests which makes it a viable candidate for powering wearable electronics.

Flexible and wearable electronic devices are of a high academic and industrial interest. In order to power these devices, there is a need for compatible energy storage units that can exhibit similar mechanical flexibility. Fiber-based devices have thus become increasingly popular since their light-weight, and flexible structure can be easily integrated into textiles. Supercapacitors have garnered a lot of attention due to their excellent cycling durability, fast charge times and superior power density. The primary challenge, however, with electric double layer capacitors (EDLCs), which are part of the supercapacitor family, is that their energy densities are significantly lower compared to those of batteries. Pseudocapacitors, on the other hand, can be designed and created with large energy densities and other outstanding properties typical for supercapacitors. This chapter discusses the fabrication and testing of supercapacitors based on carbon nanotube-polyaniline (PANI) composite fibers. These flexible and light-weight devices are assembled using different electrolytes for comparison. The created in this work PANI-CNT composite devices attain an energy density of 6.16 Wh/kg at a power density of 630 W/kg and retained a capacitance of 88% over 1000 charge-discharge cycles.

A finite element model of a lightweight vehicle body-in-white has been developed to study the contribution of a lightweight vehicle's glazing system to its overall structural rigidity. This paper examines the effect of the glazing thickness and glazing molding stiffness on the glazing system contribution to a lightweight vehicle's torsional rigidity. The individual stiffness contributions of the front and back glazing were determined, as well as the weight of the glazing as a function of its thickness. In the first set of analyses detailed in this paper, the torsional and bending loadcase was investigated by comparing the baseline model to a no-glass model. It was shown that the glazing system contributes significantly to the overall structural rigidity of the auto-body. The difference was mainly in the torsional rigidity which was 12.4% more rigid than the no-glass model. The bending rigidity was only increased by 0.5% in the glazing model. Since this was the case, further investigation on the torsional rigidity was necessary. The next step was conducted using the lightweight vehicle model to determine the effect of the glazing thickness and glazing molding stiffness on the glazing system contribution to the lightweight vehicle's torsional rigidity. Only torsional loading is considered here because in the previous analyses it was determined that the glazing system did not significantly contribute to the car's bending stiffness. First, analyses were conducted in which the glazing thickness and molding stiffness were independently varied by application of a scale factor to the baseline values. For each analysis, the car's torsional stiffness was calculated. A curve fit was performed on the results to yield a relation for the torsional stiffness as a function of both the glazing thickness and the glazing molding stiffness. In order to test this relation, further analyses were conducted in which the glazing thickness and glazing molding stiffness were varied concurrently by the same amount. The results of these analyses served to validate the curve fit. Both the curve fit and the data show that the glazing thickness can be significantly increased or reduced with only a minimal change in torsional stiffness contribution. The results also show a marginal gain in torsional stiffness contribution from increasing the glazing molding stiffness and a significant loss in torsional stiffness contribution from decreasing the glazing molding stiffness. Two analyses were conducted to determine the individual contributions of the front and back glazing to the car's torsional stiffness. These analyses used the baseline values of the glazing thickness and molding stiffness. In each analysis, either the front or back glazing was removed from the car and the resulting torsional stiffness was calculated. The results of these analyses show that the front glazing provides 10.2% of the glazing system's contribution to the car's torsional stiffness and the back glazing provides 2.2%. Finally, the weight of the glazing as a function of the front and back glazing thicknesses was calculated. It was determined that the glazing weight is linearly proportional to its thickness. With the baseline values for front and back glazing thickness, the total glazing mass is 22.27 kg. The masses of the front and back glazing make up 62% and 38% of this figure, respectively.