Based on a tight-binding model for the electron system, we investigate the transfer of energy, momentum, and angular momentum mediated by electromagnetic fields among buckminsterfullerene ( C 60 ) and graphene nanostrips. Our nonequilibrium Green's function approach enables calculations away from local thermal equilibrium where the fluctuation-dissipation theorem breaks down. For example, the forces between C 60 and current-carrying nanostrips are predicted. It is found that the presence of current enhances the van der Waals attractive forces. For two current-carrying graphene strips rotated at some angle, the fluctuational force and torque are much stronger at the nanoscale compared to that of the static Biot-Savart law.

The near-field radiative heat transfer (NFRHT) between one-dimensional metamaterials comprised of phonon dielectric multilayers was investigated experimentally. Large-size (1 × 1 cm 2 ) near-field samples were fabricated using Si C , Si O 2 , and Ge layers at a certain gap distance, and the effects of layer-stacking order and phonon-resonance quality on NFRHT were examined. The measured results show good agreement with the theoretical results obtained by employing the transmission-matrix method. Super-Planckian thermal radiation was observed between emitters and receivers with identical structures. The failure of effective-medium theory (EMT) at predicting the near-field heat flux has been evidenced by measurements, particularly in the presence of bounded surface modes, such as the epsilon-near-zero mode. Additionally, analyses have shown that, in specific scenarios, the EMT can offer reasonable physical insights into the underlying coupling process from the perspective of homogenized media. Furthermore, the conditions for applying the EMT in the near-field regime were also touched upon.

I'll review the known results about BPS indices, which encode in particular the entropy of BPS black holes, appearing in string compactifications down to four dimensions with various number of supersymmetries. First, I'll recall the well-known results about BPS states in N=8 and N=4 compactifications, and then present what is known about them in the N=2 case. Depending on time, I hope to cover some recent advances where an important role was played by (mock) modular symmetry.

We numerically elucidate the microscopic mechanisms controlling the relaxation dynamics of a three-dimensional lattice glass model that has static properties compatible with the approach to a random first-order transition. At low temperatures, the relaxation is triggered by a small population of particles with low-energy barriers forming mobile clusters. These emerging quasiparticles act as facilitating defects responsible for the spatially heterogeneous dynamics of the system, whose characteristic lengthscales remain strongly coupled to thermodynamic fluctuations. We compare our findings both with existing theoretical models and atomistic simulations of glass-formers.

Xylem sap flow measurement is a key method to quantify plant water use and assess the responses to environmental conditions and climatic change. However, available methods are generally invasive and of limited portability. This paper presents a non-invasive approach called TIMFLOW that combines microwave heat pulse and infrared thermography, while having a high portability and versatility potential. The methodology was tested in laboratory conditions for black poplar (Populus nigra) stems of various diameters (10–45 mm) and for the known sap flow velocity range (10–100 cm h−1). The heat pulse was generated by microwaves with a power amplifier supplying a bi-quad antenna at 2.45 GHz frequency located near the stem. The scene was filmed using a relatively low-cost light and compact InfraRed (IR) thermography camera. A stem temperature map was used to determine the heat pulse propagation velocity. The calculated heat velocity was highly correlated with the applied flow velocity with a unique relationship regardless of the diameter. The latter result confirms the equation of Marshall (1958) which links the sap velocity to the heat velocity with a vessel fraction of around 25 % within samples. The feasibility of outdoor measurements was also successfully tested. The assumed potentials and limitations of the proposed methodology are discussed. In summary, the study demonstrates the concept and validates, in woody stems, this new methodology for non-invasive portable sap flow velocity measurement.

The addition of water to native cellulose/1-ethyl-3methylimidazolium acetate solutions catalyzes the formation of gels, where polymer chain-chain intermolecular associations act as cross-links. However, the relationship between water content (Wc), polymer concentration (Cp), and gel strength is still missing. This study provides the fundamentals to design water-induced gels. First, the sol-gel transition occurs exclusively in entangled solutions, while in unentangled ones, intramolecular associations hamper interchain cross-linking, preventing the gel formation. In entangled systems, the addition of water has a dual impact: at low water concentrations, the gel modulus is water-independent and controlled by entanglements. As water increases, more cross-links per chain than entanglements emerge, causing the modulus of the gel to scale as Gp ∼ C p^2 Wc^3.0±0.2. Immersing the solutions in water yields hydrogels with noncrystalline, aggregate-rich structures. Such water-ionic liquid exchange is examined via Raman, FTIR, and WAXS. Our findings provide avenues for designing biogels with desired rheological properties.