Cooling Performance of TiO-Based Radiative Cooling Coating in Tropical Conditions.

The cooling power of radiative cooling (RC) coatings depends not only on the radiative properties of the coating but also on environmental variables. In tropical environments, the cooling performance of RC coatings deteriorates due to high humidity and high solar radiation. Previous studies focused on developing high solar-reflective coatings to achieve subambient cooling in tropical environments.

Tunability in 3-Site Electronic Excitation Transfer Dynamics: Insights into the Role of Perturbative Coupling.

Electronic excitation transfer dynamics in photosynthetic systems, including the Fenna-Matthews-Olson complex, are often modeled using the interaction picture of three two-level systems, also known as the 3-site system. Among the two possible configurations, uphill and downhill, a recent publication reported an intriguing correlation between population dynamics and the intersite coupling. Specifically, the uphill configuration has been shown to have a pronounced dependence on perturbations in the intersite coupling, whereas the downhill configuration displays negligible dependence.

Vibrational Dipole-Dipole Coupling and Long-Range Forces between Macromolecules.

Long-range interactions between biomacromolecules are considered important for directing intracellular processes. Recent studies have posited that interactions between oscillating dipoles are well-suited to mediating long-range forces because they are weakly screened by a dielectric environment. Here, we extend these studies and present a quantum electrodynamic mechanism for resonant interactions between vibrational transition dipole moments of molecules.

Semi-analytical technique for the design of disordered coatings with tailored optical properties.

Disordered media coatings are finding increasing use in applications such as day-time radiative cooling paints and solar thermal absorber plate coatings which require tailored optical properties over a broad spectrum ranging from visible to far-IR wavelengths. Both monodisperse and polydisperse configurations with thickness of coatings up to 500 µm are currently being explored for use in these applications. In such cases it becomes increasingly important to explore utility of analytical and semi-analytical methods for design of such coatings to help reduce the computational cost and time for design.

Near-field radiative transfer between two unequal sized spheres with large size disparities.

We compute near-field radiative transfer between two spheres of unequal radii R1 and R2 such that R2 ≲ 40R1. For R2 = 40R1, the smallest gap to which we have been able to compute radiative transfer is d = 0.016R1.

Convergence of vector spherical wave expansion method applied to near-field radiative transfer.

Near-field radiative transfer between two objects can be computed using Rytov's theory of fluctuational electrodynamics in which the strength of electromagnetic sources is related to temperature through the fluctuation-dissipation theorem, and the resultant energy transfer is described using the dyadic Green's function of the vector Helmholtz equation. When the two objects are spheres, the dyadic Green's function can be expanded in a series of vector spherical waves. Based on comparison with the convergence criterion for the case of radiative transfer between two parallel surfaces, we derive a relation for the number of vector spherical waves required for convergence in the case of radiative transfer between two spheres.