Department of Physics, Occidental College, 1600 Campus Road, M21, Los Angeles, California 90041, USA.
Published: October 2016
AI Article Synopsis
Article Abstract
An extreme dissipation event in the bulk of a closed three-dimensional turbulent convection cell is found to be correlated with a strong reduction of the large-scale circulation flow in the system that happens at the same time as a plume emission event from the bottom plate. The reduction in the large-scale circulation opens the possibility for a nearly frontal collision of down- and upwelling plumes and the generation of a high-amplitude thermal dissipation layer in the bulk. This collision is locally connected to a subsequent high-amplitude energy dissipation event in the form of a strong shear layer. Our analysis illustrates the impact of transitions in the large-scale structures on extreme events at the smallest scales of the turbulence, a direct link that is observed in a flow with boundary layers. We also show that detection of extreme dissipation events which determine the far-tail statistics of the dissipation fields in the bulk requires long-time integrations of the equations of motion over at least a hundred convective time units.
Premise: Tree structure and function are constrained by and acclimate to climatic conditions. Drought limits plant growth and carbon acquisition and can result in "legacy" effects that last beyond the period of water stress. Leaf and twig-level legacy effects of past water abundance, such as that experienced by trees that established under wetter conditions are unknown.
Guangxi Key Laboratory of Clean Pulp & Papermaking and Pollution Control, School of Light Industry and Food Engineering, Guangxi University, Nanning, 530004, China.
With the increasing global focus on sustainable materials, paper is favored for its biodegradability and low cost. Their integration with triboelectric nanogenerators (TENGs) establishes broad prospects for self-powered, paper-based triboelectric materials. However, these materials inherently lack efficient charge storage structures, leading to rapid charge dissipation.
Planck's law ignores but does not prohibit black-body radiation (BBR) from being circularly polarized. BBR from nanostructured filaments with twisted geometry from nanocarbon or metal has strong ellipticity from 500 to 3000 nanometers. The submicrometer-scale chirality of these filaments satisfies the dimensionality requirements imposed by fluctuation-dissipation theorem and requires symmetry breaking in absorptivity and emissivity according to Kirchhoff's law.
High-temperature polymer capacitors with superior energy storage density are considerable and desirable components in advanced power pulse, electrical, and energy conversion systems. However, due to the π-π conjugated benzene ring structure, carriers migrate through polyimide (PI) chains, reducing discharge energy density () and charge-discharge efficiency (η) at high temperature. Here, the ether (-O-) and isopropylidene (-C(CH)-) groups are purposefully introduced into the position between the benzene rings to increase the conjugate angle in PI chains, and spatial folded chains are designed to impede charge transport at high temperature.
Bone, consisting of calcium phosphate minerals, rigid collagen fibrils, and acidic proteins, exhibits stiff and tough mechanical properties. On a molecular scale, covalent cross-linking in proteins and ionic interactions within proteins and at the protein-mineral boundary contribute to bone's toughness. In addition, hierarchical structures, like the sponge-like arrangement, are also crucial for the energy dissipation system in bone.
