Search results for " Dissipation"
showing 10 items of 80 documents
In vivo photoprotection mechanisms observed from leaf spectral absorbance changes showing VIS–NIR slow-induced conformational pigment bed changes
2019
Abstract Regulated heat dissipation under excessive light comprises a complexity of mechanisms, whereby the supramolecular light-harvesting pigment–protein complex (LHC) shifts state from light harvesting towards heat dissipation, quenching the excess of photo-induced excitation energy in a non-photochemical way. Based on whole-leaf spectroscopy measuring upward and downward spectral radiance fluxes, we studied spectrally contiguous (hyperspectral) transient time series of absorbance A(λ,t) and passively induced chlorophyll fluorescence F(λ,t) dynamics of intact leaves in the visible and near-infrared wavelengths (VIS–NIR, 400–800 nm) after sudden strong natural-like illumination exposure. …
Efficient Protection for VDI Workstations
2019
Many enterprises migrate to a private cloud VDI environment. In such an environment multiple workstations are served by a single powerful server. On such an environment each VDI workstation receives only a limited CPU power. An average of less than a quarter of a core per planned VDI workstation is a common setup. Under such cases, anti-virus and application control software load is multiplied by the number of VDI workstation running on each server. These security applications take merely a few percentages of a single core on a normal desktop. However, on a VDI server where the multiple VDI workstations run on a single server, they may consume 20-25 percent the load. Naturally, such an incr…
Seismic behavior of structures equipped with variable friction dissipative (VFD) systems
2021
Usually, to mitigate the stresses in framed structures, different strategies are used. Among them, base isolation, viscous/friction/metallic yielding dampers and tuned mass dumpers have been widely investigated. Fluid Viscous Dampers (FVD) probably result the most diffused for the simplicity in the applications. However, these type of dampers request limited interstorey drifts to avoid dangerous effects. Further, they have an elevate cost. On the contrary, friction dampers are not so expensive but request high interstorey drifts to give a significant contribute in the dissipation of energy during an earthquake. In this paper an approach for the energy dissipation by friction, modified with …
On the Use of the Eddy Covariance Latent Heat Flux and Sap Flow Transpiration for the Validation of a Surface Energy Balance Model
2018
Actual evapotranspiration is assessed via surface energy balance at an hourly rate. However, a robust estimation of daily evapotranspiration from hourly values is required. Outcomes of surface energy balance are frequently determined via measures of eddy covariance latent heat flux. Surface energy balance can be applied on images acquired at different times and spatial resolutions. In addition, hourly actual evapotranspiration needs to be integrated at a daily rate for operational uses. Questions arise whether the validation of surface energy balance models can benefit from complementary in situ measures of latent heat flux and sap flow transpiration. Here, validation was driven by image ac…
The promise of spintronics for unconventional computing
2021
Novel computational paradigms may provide the blueprint to help solving the time and energy limitations that we face with our modern computers, and provide solutions to complex problems more efficiently (with reduced time, power consumption and/or less device footprint) than is currently possible with standard approaches. Spintronics offers a promising basis for the development of efficient devices and unconventional operations for at least three main reasons: (i) the low-power requirements of spin-based devices, i.e., requiring no standby power for operation and the possibility to write information with small dynamic energy dissipation, (ii) the strong nonlinearity, time nonlocality, and/o…
Decoherence of the Exciton and Decay of the Excitonic Polaron in Quantum Dots
2005
Bulk-phonon mechanisms of decoherence of an exciton confined in a quantum dot (QD) are considered in order to establish time limitations for the coherent control of the exciton with relevance to its application in quantum information processing. These are the formation and decay of the excitonic polaron. The estimations of characteristic dephasing times for the InAs/GaAs QD are discussed.
Thermodynamically consistent residual-based gradient plasticity theory and comparison
2006
A gradient plasticity theory for small deformations is presented within the framework of nonlocal continuum thermodynamics. The second principle (Clausius–Duhem inequality), enriched by an additional term named energy residual, is employed in conjunction with the concepts of insulation condition and locality recovery condition, in order to derive all the pertinent restrictions upon the constitutive equations. These include the expressions of the energy residual and of the plastic dissipation density, as well as the PDEs governing the gradient kinematic and isotropic hardening of the material, together with the related higher-order boundary conditions for both the fixed and the moving bounda…
Viscous dissipation and thermoconvective instabilities in a horizontal porous channel heated from below
2010
Accepted version of av article from the journal: International Journal of Thermal Sciences. Published version available on Science Direct: http://dx.doi.org/10.1016/j.ijthermalsci.2009.10.010 A linear stability analysis of the basic uniform flow in a horizontal porous channel with a rectangular cross section is carried out. The thermal boundary conditions at the impermeable channel walls are: uniform incoming heat flux at the bottom wall, uniform temperature at the top wall, adiabatic lateral walls. Thermoconvective instabilities are caused by the incoming heat flux at the bottom wall and by the internal viscous heating. Linear stability against transverse or longitudinal roll disturbances …
Darcy–Forchheimer Magnetized Nanofluid flow along with Heating and Dissipation Effects over a Shrinking Exponential Sheet with Stability Analysis
2022
Nanoparticles have presented various hurdles to the scientific community during the past decade. The nanoparticles dispersed in diverse base fluids can alter the properties of fluid flow and heat transmission. In the current examination, a mathematical model for the 2D magnetohydrodynamic (MHD) Darcy–Forchheimer nanofluid flow across an exponentially contracting sheet is presented. In this mathematical model, the effects of viscous dissipation, joule heating, first-order velocity, and thermal slip conditions are also examined. Using similarity transformations, a system of partial differential equations (PDEs) is converted into a set of ordinary differential equations (ODEs). The problem is …
Influence of protecting devices on the optimal design of elastic plastic structures
2008
The paper concerns the minimum volume design of structures constituted by elastic perfectly plastic material. The relevant optimal design problem is formulated on the grounds of a statical approach and two different resistance limits are considered: in particular, it is required that the optimal structure satisfies the elastic shakedown limit and the instantaneous collapse limit, imposing for each different condition a suitably chosen safety factor. For sake of generality, the structure is thought as discretized into compatible finite elements and subjected to loads quasi-statically acting as well as to dynamic (seismic) loads. The effects of the dynamic actions are studied on the grounds o…