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This presentation details the current project status and approach for the VTO funded project "Holistic Modeling of Future Transportation Energy Use and Emissions" using the TEMPO model.
This presentation details the current project status and approach for the VTO funded project "Holistic Modeling of Future Transportation Energy Use and Emissions" using the TEMPO model.
Planar black holes in AdS, which are holographically dual to compressible relativistic fluids, have a long-lived phonon mode that captures the physics of attenuated sound propagation and transports energy in the plasma. We describe the open effective field theory of this fluctuating phonon degree of freedom. The dynamics of the phonon is encoded in a single scalar field whose gravitational coupling has non-trivial spatial momentum dependence. This description fits neatly into the paradigm of classifying gravitational modes by their Markovianity index, depending on whether they are long-lived. The sound scalar is a non-Markovian field with index 3 - d for a d-dimensional fluid. We reproduce (and extend) the dispersion relation of the holographic sound mode to quartic order in derivatives, constructing in the process the effective field theory governing its attenuated dynamics and associated stochastic fluctuations. We also remark on the presence of additional spatially homogeneous zero modes in the gravitational problem, which remain disconnected from the phonon Goldstone mode.
Here, we use quantum trajectory theory to study the dynamics of the first step in photosynthesis for a single photon interacting with photosystem II (PSII). By considering individual trajectories we are able to look beyond the ensemble average dynamics to compute the PSII system evolution conditioned upon individual photon counting measurements. Measurements of the transmitted photon beam strongly affects the system state, since detection of an outgoing photon confirms that the PSII must be in the electronic ground state, while a null measurement implies it is in an excited electronic state. We show that under ideal conditions, observing the null result transforms a state with a low excited state population to a state with nearly all population contained in the excited states. We study the PSII dynamics conditioned on such photon counting for both a pure excitonic model of PSII and a more realistic model with exciton-phonon coupling to a dissipative phononic environment. In the absence of such coupling, we show that the measured fluorescence rates show oscillations constituting a photon-counting witness of excitonic coherence. Excitonic coupling to the phonon environment has a strong effect on the observed rates of fluorescence, damping the oscillations. Addition of non-radiative decay and incoherent transitions to radical pair states in the reaction center to the phononic model allows extraction of a quantum efficiency of 92.5% from the long-time evolution, consistent with bulk experimental measurements.
A model is presented for the prediction of solid/liquid, binary alloy, phase change energy transport. The model incorporates only one-dimensional, diffusive transport of both energy and species but is not inherently limited in any way to such a restriction. The model incorporates a previously developed algorithm for single constituent phase change energy transport and is applied to the energy transport as well as the species transport aspects of the problem. The model is applied to four example cooling problems and is shown to perform exceedingly well from an algorithmic point of view.
Radiant energy transport within cryogenic condensates
Abstract Ultrafast X‐ray diffraction is used to quantify the transport of energy in laser‐excited nanoscale gold–nickel (Au–Ni) bilayers. Electron transport and efficient electron–phonon coupling in Ni convert the laser‐deposited energy in the conduction electrons within a few picoseconds into a strong non‐equilibrium between hot Ni and cold Au phonons at the bilayer interface. Modeling of the subsequent equilibration dynamics within various two‐temperature models confirms that for ultrathin Au films, the thermal transport is dominated by phonons instead of conduction electrons because of the weak electron–phonon coupling in Au.
We report findings concerning energy transport and dynamics in flares during the impulsive and gradual phases based on new ground-based and space observations (notably from Yohkoh). A preheating sometimes occurs during the impulsive phase. Ca XIX line shifts are confirmed to be good tracers of bulk plasma motions, although strong blue shifts are not as frequent as previously claimed. They often appear correlated with hard X-rays but, for some events, the concept that electron beams provide the whole energy input to the thermal component seems not to apply. Theory now yields: new diagnostics of low-energy proton and electric beams; accurate hydrodynamical modeling of pulse beam heating of the atmosphere; possible diagnostics of microflares (based on X-ray line ratio or on loop variability); and simulated images of chromospheric evaporation fronts. For the gradual phase, the continual reorganization of magnetic field lines over active regions determines where and when magnetic reconnection, the mechanism favored for energy release, will occur. Spatial and temporal fragmentation of the energy release, observed at different wavelengths, is considered to be a factor as well in energy transport and plasma dynamics.
Understanding global monsoon (GM) variability and projecting its future changes rely heavily on climate models. However, climate models generally show pronounced biases in GM simulations, and the reasons for this remain unclear. Here, in this study, we evaluate the performance of 20 pairs of climate models that participated in both phase 5 of the Coupled Model Intercomparison Project (CMIP5) and phase 6 of CMIP (CMIP6) and identify the sources of their GM simulation biases from an energy transport perspective. The multimodel mean improvement in CMIP6 compared to CMIP5 is demonstrated by the increasing skill scores for various GM metrics from 0.20–0.79 to 0.48–0.83. More specifically, the dry biases in the Northern Hemisphere Summer Monsoon (NHSM) precipitation in CMIP5 [root-mean-square error (RMSE): 1.85 mm day −1 ] are reduced in CMIP6 (RMSE: 1.66 mm day −1 ). This higher simulation skill is associated with higher skill in simulating the precipitation-solstitial mode, monsoon intensity, and monsoon domains. The improvement in the NHSM precipitation simulation results from that in the meridional transport of atmospheric energy. Atmospheric energy budget analysis shows that the negative biases in downward surface longwave radiation and northward energy transport are smaller in CMIP6 than in CMIP5 in the boreal summer, resulting in a more realistic interhemispheric thermal contrast and meridional gradient of moist static energy. However, a major weakness of the CMIP6 models is found in the Southern Hemisphere Summer Monsoon precipitation simulation due to the positive bias in the top-of-the-atmosphere downward longwave radiation. This study shows that reasonably reproducing the meridional global atmospheric energy transportation is necessary for skillful GM simulation.
Radiant energy transport within cryogenic condensates extended to case of explicitly varying condensate depths and wider substrate temperature range
This report investigates the impact of differential net radiative heating on 2D energy transports within the atmosphere ocean system and the role of clouds on this process. The 2D mean energy transports, in answer to zonal and meridional gradients in the net radiation field, show an east-west coupled dipole structure in which the Pacific acts as the major energy source and North Africa as the major energy sink. It is demonstrated that the dipole is embedded in the secondary energy transports arising mainly from the differential heating between land and oceans in the tropics in which the tropical east-west (zonal) transports are up to 30 percent of the tropical north-south (meridional) transports.
The energy transport through the solar atmosphere and the source of energy which heats the chromosphere and the solar corona are studied. Wave propagation in the solar atmosphere and in the heating of the solar atmosphere is discussed as a source and transport medium. The source of the waves is thought to be the photospheric short period oscillations. Simultaneous observations from the photosphere to the corona at the solar disk center are reported. Emphasis is on the possible association of aperiodic brightenings high in the atmosphere with specific events in the photosphere.
Abstract Determining the relative energies of transport states in organic semiconductors is critical to understanding the properties of electronic devices and in designing device stacks. Futhermore, defect states are also highly important and can greatly impact material properties and device performance. Recently, energy‐resolved electrochemical impedance spectroscopy (ER‐EIS) is developed to probe both the ionization energy (IE) and electron affinity (EA) as well as sub‐bandgap defect states in organic semiconductors. Herein, ER‐EIS is compared to cyclic voltammetry (CV) and photoemission spectroscopies for extracting IE and EA values, and to photothermal deflection spectroscopy (PDS) for probing defect states in both polymer and molecular organic semiconductors. The results show that ER‐EIS determined IE and EA are in better agreement with photoemission spectroscopy measurements as compared to CV for both polymer and molecular materials. Furthermore, the defect states detected by ER‐EIS agree with sub‐bandgap features detected by PDS. Surprisingly, ER‐EIS measurements of regiorandom and regioregular poly(3‐hexylthiophene) (P3HT) show clear defect bands that occur at significantly different energies. In regioregular P3HT the defect band is near the edge of the occupied states while it is near the edge of the unoccupied states in regiorandom P3HT.
The 'radial' transport of energy by internal ULF waves, stimulated by dayside magnetospheric boundary oscillations, is analyzed in the framework of one-fluid magnetohydrodynamics. (the term radial is used here to denote the direction orthogonal to geomagnetic flux surfaces.) The model for the inhomogeneous magnetospheric plasma and background magnetic field is axisymmetric and includes radial and parallel variations in the magnetic field, magnetic curvature, plasma density, and low but finite plasma pressure. The radial mode structure of the coupled fast and intermediate MHD waves is determined by numerical solution of the inhomogeneous wave equation; the parallel mode structure is characterized by a Wentzel-Kramer-Brillouin (WKB) approximation. Ionospheric dissipation is modeled by allowing the parallel wave number to be complex. For boudnary oscillations with frequencies in the range from 10 to 48 mHz, and using a dipole model for the background magnetic field, the combined effects of magnetic curvature and finite plasma pressure are shown to (1) enhance the amplitude of field line resonances by as much as a factor of 2 relative to values obtained in a cold plasma or box-model approximation for the dayside magnetosphere; (2) increase the energy flux delivered to a given resonance by a factor of 2-4; and (3) broaden the spectral width of the resonance by a factor of 2-3. The effects are attributed to the existence of an 'Alfven buoyancy oscillation,' which approaches the usual shear mode Alfven wave at resonance, but unlike the shear Alfven mode, it is dispersive at short perpendicular wavelengths. The form of dispersion is analogous to that of an internal atmospheric gravity wave, with the magnetic tension of the curved background field providing the restoring force and allowing radial propagation of the mode. For nominal dayside parameters, the propagation band of the Alfven buoyancy wave occurs between the location of its (field line) resonance and that of the fast mode cutoff that exists at larger radial distances.
Coordinated observations of a GOES B4.8 microflare with SDOs Atmospheric Imaging Assembly (AIA) and the RamatyHigh Energy Solar Spectroscopic Imager (RHESSI) on 2010 July 31 show that emission in all seven of AIAs EUV channels brightened simultaneously nearly 6 min before RHESSI or GOES detected emission from plasma at temperatures around 10 MK. Aims. To help interpret these and AIA flare observations in general, we characterized the expected temporal responses of AIAs 94, 131, 171, 193, 211, and 335 channels to solar flare brightenings by combining (1) AIAs nominal temperature response functions available through SSWIDL with (2) EUV spectral line data observed in a flare loop Coordinated observations of a GOES B4.8 microflare with SDOs Atmospheric Imaging Assembly (AIA) and the RamatyHigh Energy Solar Spectroscopic Imager (RHESSI) on 2010 July 31 show that emission in all seven of AIAs EUV channels brightenedsimultaneously nearly 6 min before RHESSI or GOES detected emission from plasma at temperatures around 10 MK.Aims. To help interpret these and AIA flare observations in general, we characterized the expected temporal responses of AIAs 94,131, 171, 193, 211, and 335 channels to solar flare brightenings by combining (1) AIAs nominal temperature response functionsavailable through SSWIDL with (2) EUV spectral line data observed in a flare loop
The overarching goal of this project is to understand how the phase coherence of phonons and the interaction of phonons with other microscopic degrees of freedom in nanomaterials, such as 2D materials, can affect the energy transport properties and eventually lead to control of energy transport by manipulating phonon interference and phonon scatterings. On the computational side, we are developing and applying first-principles methods to study emerging phonon properties in nanomaterials, including coherent phonons, resonant bonding and gate-tunable phonon-electron scatterings, which hold the promise of enabling significant tunability of energy transport processes with external fields for a wide range of applications. On the experimental side, we are developing ultrafast transient grating spectroscopy and scanning ultrafast electron microscopy (SUEM) to directly probe the coherent phonon transport and phonon-electron interaction processes in nanomaterials with high combined spatial-temporal resolutions. This program will not only provide new insights into the microscopic transport and interaction processes of fundamental energy carriers, but also open new venue towards energy-relevant applications such as thermal switches and coherent energy harvesters.
Sunspot energy transport from oscillatory instabilities indicated from calculations on hydromagnetic stability of thermally unstable layers with open boundary conditions