This research study presents a resilient control scheme for an islanded DC microgrid (DC MG) integrating solar photovoltaic (PV), battery storage (BESS), and piezoelectric (PE) energy harvesting modules. The microgrid (MG) case study represents an energy hub designed to provide electricity for lighting systems in transportation, roads, and other infrastructure. To enhance practicality, the PE is modeled using the real data captured from a traffic simulator. The proposed reinforcement learning (RL) method was tested against four severe and unexpected failure scenarios, including short circuit at the load side, sudden and severe change of load, open circuit, and converter failure. The performance of the controller was quantitatively compared with a conventional PI controller. The results show marginal improvement in one scenario and significant improvement in the other three, suggesting that the proposed scheme is a robust candidate for microgrids with high levels of uncertainty, such as those involving solar and PE harvesters.

This study objective to assess the effects of Waste Engine Oil (WEO) and Sasobit on improving the rheological and physicochemical properties of Reclaimed Asphalt Pavement (RAP), both of which are considered waste materials. Seven asphalt mixes were prepared with varying percentages of these materials. The study included rheological testing, Fourier Transform Infrared Spectroscopy (FTIR) analysis, cost–benefit analysis, and final stage to select blend selection. Highway agencies typically limit RAP usage to 20% due to concerns such as fatigue and low-temperature cracking. To address these issues and increase the RAP content, rejuvenators are often required to soften the aged binder. This study investigated the use of WEO and Sasobit as rejuvenators, with WEO added at dosages of 4% and 8%, and Sasobit at 1%, 2%, and 3%. The penetration and viscosity methods were employed to determine the optimal amounts of WEO and Sasobit. The selected mixtures were tested for rutting resistance, fatigue performance, and low-temperature cracking susceptibility. FTIR was used to further analyze the blends, along with a cost analysis. The results indicated that 4% WEO was effective in rejuvenating 25% of the reclaimed binder, offering a cost-effective solution. While Sasobit did not function as a rejuvenator, it proved beneficial as a viscosity reducer.

Geothermal energy presents a promising opportunity for sustainable and efficient energy production. To maximize the efficiency of geothermal systems, developing advanced materials capable of effectively transferring and withstanding thermal loads is crucial. This study focuses on demonstrating highly conductive nano-engineered geopolymer cement tailored for geothermal applications using prototype laboratory samples. The study included an evaluation of thermal conductivity, shear bond strength, and compressive strength of newly designed geopolymer mixtures as well as the thermal conductivity of large-scale geopolymer samples, with a specific emphasis on their performance in the handling fluid flow for enhanced geothermal systems. The results showed that, compared to the control geopolymer, the developed geopolymer formulations had a lower thermal conductivity performance due to higher air voids in the system. In general, the addition of carbon nanotubes and graphite in geopolymer mixtures reduces the strength and elastic modulus. The thermal conductivity of the large prototype sample cured for 7 days at 49 °C showed better thermal conductivity for the control geopolymer. Conversely, the water flow data reflected better performance for the modified mixtures. Additionally, numerical simulations were developed and validated by the experimental observations for further studies on the effect of geopolymer properties on the performance of geothermal systems.