The Center for Energy and Environmental Sustainability (CEES) was established in October 2010 with $5M in funding from NSF. CEES Phase II award from NSF started on October 1, 2019. CEES personnel include eight faculty members, 1 program coordinator, and 4 research staff members. CEES is addressing the challenging interdisciplinary problems and is paving the way for scientific and technological breakthroughs in energy engineering to meet short- and long-term national needs. The Center’s research mission is accomplished through 3 distinct research thrust areas and strong education and outreach programs. The research areas include Bio-Energy (Energy crop cultivation and gasoline/diesel-like hydrocarbon fuel production from energy crops), Offshore Wind Energy (Massive offshore power generation and risk analysis with big data), and Environmental Sustainability (Produced water treatment and environmental impact evaluation with life cycle assessment). The Center’s education and outreach activities are carried through the Energy Engineering and Research Learning Initiative (EERLI), which includes a myriad of activities that engage K-12 students through graduate students. The researchers, including our students, have published 1 book, 185 peer-reviewed publications and have given more than 220 presentations at regional, national, and international conferences. CEES faculty and staff are also supported by other leveraged funding of about $12.82 M from NSF, USDA, Tran-SET, and industrial partners. CEES has supported more than 220 students, including 73 graduate, and 145 undergraduate students. The Center also established state-of-the-art research laboratories with high-quality equipment using leveraged funds.

Center for Energy & Environmental Sustainability (CEES)

Heating and cooling systems in buildings account for 31% of global energy use, much of which are regulated by Rule Based Controllers (RBCs) that neither maximise energy efficiency nor minimise emissions by interacting optimally with the grid. Control via Reinforcement Learning (RL) has been shown to significantly improve building energy efficiency, but existing solutions require access to building-specific simulators or data that cannot be expected for every building in the world. In response, we show it is possible to obtain emission-reducing policies without such knowledge a priori–a paradigm we call zero-shot building control. We combine ideas from system identification and model-based RL to create PEARL (Probabilistic Emission-Abating Reinforcement Learning) and show that a short period of active exploration is all that is required to build a performant model. In experiments across three varied building energy simulations, we show PEARL outperforms an existing RBC once, and popular RL baselines in all cases, reducing building emissions by as much as 31% whilst maintaining thermal comfort. Our source code is available online via: https://enjeeneer.io/projects/pearl/.

Low Emission Building Control with Zero-Shot Reinforcement Learning

In 2017, Cambodian and American activists, alongside the Cambodian Government, temporarily halted deportations of Cambodian American refugees from the U.S. However, mere months later, after the United States Government issued retaliatory visa sanctions against Cambodia, deportations not only resumed, but increased in frequency and number, and included more disabled and dying individuals. Nonetheless, activists argue these efforts sparked more “wins” in the fight to change deportation policy, thereby exemplifying “the egg versus the rock”•a Khmer maxim used to signify when those with relatively less power (the egg) challenge those with more (the rock). When the two collide, although the egg ultimately loses, it still stains, and therefore damages, the rock. With this aphorism as a starting point, I ask what it means to engage in such policy challenges to the deportation of Cambodian American refugees with lawful permanent residency in the United States. Thinking through both the above-mentioned example as well as lawsuits and pardon campaigns to halt individual deportations, I seek to destabilize static notions of who has power, and examine the role of the activist anthropologist in navigating and understanding these complex policy frameworks. Furthermore, I interrogate what it means to conduct fieldwork with various stakeholders as they attempt to enact such grassroots-level policy change•particularly when such changes have unforeseen consequences. Finally, I attend to the discomfort that emerges when the activist anthropologist is asked to engage in efforts that she believes may be contrary to the overall goals of the movement or may otherwise harm her interlocutors.

The Egg Versus the Rock: The Limits of Engaged Anthropology Among Activists

Wastewater is used water consisting of many hazardous materials. The wastewater goes through a step by step procedure for treatment and decontamination at a local wastewater facility. Once harmful bacteria is taken out of the water, it is then returned back to the community waterways. The purpose of this research project is to properly analyze and differentiate the many characteristics of the microbiota within both treated and untreated wastewater samples from the Kent County Regional Resource Recovery Facility in Milford, Delaware. We hypothesized that the microbiota will differ in diversity and microbial load among the treated and untreated wastewater samples. We tested our hypothesis using the following tests: streaking samples against Mannitol Salt Agar Plate (MSA) and a MacConkey Agar Plate (MAC) as well as gram staining. We found within the MSA plates that four samples showed no mannitol utilization while two samples were yellow in color proving it utilized mannitol. With the MAC plates all samples except for one sample utilized lactose. You can tell it utilized lactose with the pink color and growth indicating gram negative organisms. For the gram staining, 4 samples were gram negative meaning they appeared pink and also possess a thicker cell wall. 2 samples were gram positive meaning they appeared to be purple in color and possess a thinner cell wall. This data will be useful to improve and scientifically inform the wastewater facility on how well the wastewater is actually being filtered and treated.

Analysis of Treated vs Untreated Water Samples from Kent County Regional Resource Recovery Facility

Wastewater is the community’s used water and it consists of various harmful materials. This water goes through various processes to be treated at a wastewater facility such as the Kent County Regional Resource Recovery Facility. The purpose of this project is to analyze and differentiate the characteristics of the microbiota within both treated and untreated water samples from the Kent County Facility. We hypothesized that the microbiota between the treated and untreated water samples would be non identical. We tested our hypothesis via multiple characteristic tests. Those tests included gram staining, where we used Escherichia coli and Staphylococcus Epidermidis as controls, and streaking samples against a Mannitol Salt Agar Plate as well as a MacConkey Agar Plate. As we continue on to confirm our preliminary data, the treated and untreated water samples will be analyzed further for possible remediation.

Analysis of Treated vs Untreated Water Samples From Kent County Regional Resource Recovery Facility

Ocean related activities are often supported by offshore equipment with particular power demands. These are usually deployed at remote locations and have limited space, thus small energy harvesting technologies, such as photovoltaic panels or wind turbines, are used to power their instruments. However, the inherent energy sources are intermittent and have lower density and predictability than an alternative source: wave energy.1 The triboelectric nanogenerator (TENG) is a promising and efficient energy harvesting technology capable of addressing these problems as it can efficiently convert regular/irregular external mechanical energy into electrical power based on the triboelectrification and electrostatic induction effects.2-4 In this work, three TENGs based on rolling-spheres were developed and their performance compared in both a “dry” bench testing system under rotating motions, and in a large-scale wave basin under realistic sea-states installed within a scaled navigation buoy. The experiments showed that the electrical outputs of these TENGs tend to rise with increasing pitch amplitudes and decreasing period due to the increase of the spheres’ velocity. The capability of these TENGs to harvest energy from ocean waves when incorporated into a navigational buoy was demonstrated under realistic sea states. The voltage generated by the TENGs achieves maximum values for periods close to the natural period of the scaled buoy (~ 0.92 s). The wave basin tests clearly demonstrated a significant dependency of the electrical outputs on the pitch degree of freedom and the need to consider the full dynamics of the buoy, and not only that of TENGs, when subjected to the excitations of waves.

Performance of triboelectric nanogenerators based on rolling spheres motion under realistic water waves conditions

Spin-dependent thermoelectric research has drawn overwhelming attention during the last few years because of its potentiality in energy harvesting and communication applications. Waste heat from locomotives and industries can be converted into electrical and electronic signals to power their own electronics. The Anomalous Nernst effect (ANE) one of the thermomagnetic phenomena proposed to be useful for heat to electrical energy conversion even from a curved surface unlike a conventional thermoelectric module based on semiconductors. Here, we have systematically studied the ANE in polycrystalline metallic perovskite Pr0.5Sr0.5CoO3 as a function of temperature and external magnetic fields. The ANE shows a rapid increase at the onset of ferromagnetic transition (TC ~ 229 K) and after showing a broad maximum at lower temperatures, and it decreases linearly below 100 K. Magnetic field dependence of the ANE, quantified by the transverse Seebeck coefficient (Sxy), exhibits hysteresis below TC as like the magnetization. The maximum saturated value of Sxy due to ANE (~ 0.46 μVK¬-1) found near 175 K (below TC) is ~ 400 times higher than the manganite analog Pr0.5Sr0.5MnO3, and larger than other polycrystalline perovskite oxides reported to date. Our analysis suggests that ANE in this sample is most likely due to asymmetric skew scattering of charge carriers. This work may open a new pathway for the perovskite magnetic oxides for energy-saving applications.

Anomalous Nernst Effect in Bulk Pr0.5Sr0.5CoO3

The solutionization of Inconel 718 (IN718) is often terminated by rapid cooling at a rate of air cooling or faster. However, in this study, a slow cooling method utilizing furnace cooling was employed for selective laser melted (SLM) micron-TiC reinforced IN718 to investigate the interactions between the TiC particles and the matrix. Four holding temperatures of 975, 1075, 1175, and 1275 °C were chosen while the holding time was kept constant at 1 hour. It was found that the addition of micron-TiC facilitated the formation of nano-sized Ti-rich precipitates in as-printed samples. The difference in microhardness between reinforced and non-reinforced IN718 increased with increasing holding temperature, from 14.9% higher at 975 °C to 50.3% higher at 1275 °C. This was mainly attributed to the prevention of solute segregation to the grain boundary and the reduction of the susceptibility to hot cracking after adding TiC particles. The results indicate that the solute materials (Nb, Mo, and Si) were absorbed by the Ti-rich particles through Ostwald ripening mechanism instead of diffusing to the grain boundaries. The degree of absorption increased with increasing holding temperature. Moreover, grain coarsening at high solutionizing temperature was reduced substantially with the presence of Ti-rich particles due to Zener pinning. Thus, this provides a better understanding for choosing a suitable heat treatment profile for IN718 composite.

Mitigation of solute segregation after solutionization in selective laser melted Inconel 718 / micron-TiC composite

Natural ceramic composites present complex microstructures that lead to tortuous crack path and confer them high toughness. Current microreinforced composites do not yet reach the level of complexity found in natural microstructures. To achieve this, we developed an automated set up for controlling 2D microplatelet orientation using magnetic fields. The setup has 4 degrees of freedom and allows fine control of platelet angles in 3D as well as position. With our setup, we can thus build microstructured porous ceramic materials (alumina) with local orientation of microplatelets, at a concentration of about 40 vol%. Other work in our group has shown that the same setup can be used to process microstructured ceramics up to 95 vol%.
Among the infinite possible microstructures, a nacre-like helicoidal arrangement was selected due to its ability to tilt and twist the crack path. Indeed, we used an analytical model based on the laminate theory to compare energy dissipation due to mixed modes of failure. Nacre-like helicoidal arrangement was predicted to exhibit the highest energy dissipation. Then, we fabricated the hybrid microstructured porous specimen fabricated and infiltrated them with a silicone matrix. Using compression tests, our hybrid dissipated 1.6 times more energy as compared to nacre-like samples of same composition. The fabrication strategy proposed here could thus be a simple route to increase the toughness of microplatelet reinforced composites.



Energy dissipation in composites with hybrid nacre-like helicoidal microstructures

Fiber reinforced thermoplastic (FRTP) composites are gaining popularity in many industries because of their potential to be recycled, among other reasons. Filament winding is a manufacturing process suitable for the fabrication of axisymmetric components. For the filament winding of FRTP composites, the consolidation process can be carried out in-situ, where the FRTP is heated during the winding process. This enables the manufacturing process to be completed in a single step, thus allowing for higher productivity. In this study, the filament winding of glass/polyamide-6 composite using a customized in-situ consolidation setup is investigated. Instead of heating only at the nip point, infrared heaters were used to supply heat across the length of the composite component. This setup is intended to increase the exposure time of the thermoplastic to the heat source. The effectiveness of the in-situ consolidation setup is studied by evaluating the physical and mechanical properties of the consolidated FRTP components. First round of results show that the customized process can produce composite specimens with low void content (below 5%) at a line speed of 2 m/min.

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Center for Energy & Environmental Sustainability (CEES)

Low Emission Building Control with Zero-Shot Reinforcement Learning

The Egg Versus the Rock: The Limits of Engaged Anthropology Among Activists

Analysis of Treated vs Untreated Water Samples from Kent County Regional Resource Recovery Facility

Analysis of Treated vs Untreated Water Samples From Kent County Regional Resource Recovery Facility

Performance of triboelectric nanogenerators based on rolling spheres motion under realistic water waves conditions

Anomalous Nernst Effect in Bulk Pr0.5Sr0.5CoO3

Mitigation of solute segregation after solutionization in selective laser melted Inconel 718 / micron-TiC composite

Energy dissipation in composites with hybrid nacre-like helicoidal microstructures

Filament winding of glass/polyamide-6 commingled fibers with customized infrared in-situ consolidation

Turn up the dial! Resource allocation & systems modeling toward rural water maintenance services in East Africa

Assessing a Drinking Water Security Strategy in Rural Western Nepal

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