A novel genetically themed hierarchical algorithm (GTHA) has been investigated to design Fresnel lens solar concentrators that match with the distinct energy input and spatial geometry of various thermal applications. Basic heat transfer analysis of each application decides its solar energy requirement. The GTHA incorporated in MATLAB® optimizes the concentrator characteristics to secure this energy demand, balancing a minimized geometry and a maximized efficiency. The optimum concentrator is then simulated to ensure the algorithm validity. To verify the algorithmic-optimization and simulation-validation processes, two experimental applications were selected from the literature, a solar welding system for H13 steel plates and a solar Stirling engine with an aluminum-cavity receiver attached to the heater section. In each case, a flat Fresnel lens with a spot focus was algorithmically designed to supply the desired solar heat, and then a computer simulation of the optimized lens was conducted showing great comparability to the original experimental results.

One area with the greatest potential for energy savings in buildings is heating and cooling. However, it is often argued that any energy-saving techniques should not have a negative impact on comfort for inhabitants. This is where the concept of alliesthesia comes into play. This paper examines the impact of utilizing modulating temperature setpoints to take advantage of the pleasure experienced through change. Simulations were conducted using EnergyPlus to explore the potential for energy savings. It was found that savings of up to 5–15% could be achieved by modulating indoor temperatures in cooling applications. However, modulating temperature setpoints resulted in larger energy usage than constant setpoints in heating applications. Results from human comfort experiments show that modulating temperatures could lead to greater thermal pleasure than a constant temperature environment for cooling situations due to a resetting of the thermal comfort achieved when the indoor temperature is decreased. However, the same comfort benefits are not shown for heating situations. Nonetheless, the simulations and the comfort experiments together show potential for both energy savings and increased human comfort levels in cooling applications.

Biopolymer foams manufactured using CO₂ enables a novel intersection for economic, environmental, and ecological impact but limited CO₂ solubility remains a challenge. PHBV has low solubility in CO₂ while PCL has high CO₂ solubility. In this paper, PCL is used to blend into PBHV. Both unfoamed and foamed blends are examined. Foaming the binary blends at two depressurization stages with subcritical CO₂ as the blowing agent, produced open-cell and closed-cell foams with varying cellular architecture at different PHBV concentrations. Differential Scanning Calorimetry results showed that PHBV had some solubility in PCL and foams developed a PCL rich, PHBV rich and mixed phase. Scanning Electron Microscopy and pcynometry established cell size and density which reflected benefits of PCL presence. Acoustic performance showed limited benefits from foaming but mechanical performance of foams showed a significant impact from PHBV presence in PCL. Thermal performance reflected that foams were affected by the blend thermal conductivity, but the impact was significantly higher in the foams than in the unfoamed blends. The results provide a pathway to multifunctional performance in foams of high performance biopolymers such as PBHV through harnessing the CO₂ miscibility of PCL.