1,721,050 research outputs found
Advances in Photonics of Quantum Computing, Memory, and Communication VII
No full textThe proceedings contain 13 papers. The topics discussed include: QEYSSAT: a mission proposal for a quantum receiver in space; long-distance continuous-variable quantum key distribution with advanced reconciliation of a Gaussian modulation; non-monotonic quantum to classical transition in multiparticle interference; highly mode-selective quantum frequency conversion in a slab waveguide; hybrid integration for spatially-multiplexed single-photon generation; quantum nonlinear optics using cold Rydberg atoms; polariton devices and quantum fluids; the exciton-polariton microcavity as an optical transistor; quantum dot spin-photon entanglement and photon-to-spin teleportation; demonstration of a variable plasmonic beam splitter; fabrication of GaP disk resonator arrays coupled to nitrogen vacancy centers in diamond; and evaluation of the phase correlation between the optical pulses for transmission in quantum key distribution
Chromogenic Technologies for Energy Saving
Full text linkChromogenic materials and devices include a wide range of technologies that are capable of changing their spectral properties according to specific external stimuli. Several studies have shown that chromogenics can be conveniently used in building façades in order to reduce energy consumption, with other significant effects. First of all, chromogenics influence the annual energy balance of a building, achieving significant reductions in consumption for HVAC and artificial lighting. In addition, these technologies potentially improve the indoor level of visual comfort, reducing the risks of glare and excessive lighting. This brief review points to a systematic discussion—although not exhaustive and mainly limited to recent results and investigations—of the main studies that deal with building-integrated chromogenics that have appeared, so far, in the scientific literature
Effect of lithium intercalation on the photovoltaic performances of photovoltachromic cells
No full textIn the last few years, a new class of smart multifunctional photoelectrochemical devices has been attracting the interest of several academic institutions and industrial companies: photovoltachromic cells, combining the features of photoelectrochromic cells with those of dye-sensitized solar cells. Here, we report the results of a detailed electrochemical analysis aiming at investigating the electrochemical behavior of these complex photoelectrochemical devices. In particular, we have been focused on the effect of Li+ ions displacement during the coloration of the electrochromic tungsten oxide on the performances of the photovoltaic unit. As we had previously observed striking differences between the performances of the barely photovoltaic mode (with the tungsten oxide in the bleached state) and the photovoltachromic mode (with the tungsten oxide in the colored state), we thus attempted to provide a reasonable physical interpretation to the observed phenomena
Smart windows elettrocromiche
No full textUna panoramica delle attuali attività di ricerca relative alle finestre intelligenti, con particolare riferimento alle nuove tendenze e ai potenziali vantaggi per il risparmio energetico e il comfort visivo derivanti dall'integrazione nell'edificio.An overview of current research activities dealing with smart windows with special reference to new trends and potential energy saving and visual comfort advantages deriving from their building integration
Energy performance of building-integrated electrochromic and photovoltaic systems
Full text linkInnovative nanotechnology-based devices can offer multiple advantages in terms of renewable energy harvesting as well as energy saving in buildings. Among the technologies that can be used in transparent and semi-transparent building envelopes, neutral-colored perovskite-based heterojunction photovoltaic (PV) cells and solid-state electrochromic (EC) devices may play a pivotal role. These classes of devices have proven to offer significant benefits in terms of energy saving and enhancement of indoor visual comfort. In this work, the two types of technologies will be compared by considering two similar buildings equipped with glazing embodying such devices, with reference to specific climate conditions
Development, testing and evaluation of energy savings potentials of photovoltachromic windows in office buildings. A perspective study for Australian climates
No full textPhotoVoltaChromic (PVC) cells are among the emerging smart windows technologies with an interesting potential of building integration. PVC technology combines ElectroChromic materials with Dye Sensitized Solar cells in order to have a self-powered adaptive transparent film. The main advantage of this technology is to have an automatic control – potentially manually overridden – of colouration process, depending on levels of solar irradiance. Moreover, a PVC window can operate, at the same time, as a photovoltaic cell, producing energy exceeding the amount required for the colouring process. In the current study, for the first time, the full potential of PVC windows in office buildings is assessed. For this analysis, a PVC cell with a Visible Light Transmittance (VLT) variable between 16.9% and 31.5% has been selected. Australia has been considered as reference location, due to the presence, in its territory, of different climatic regions, ranging from tropical/subtropical climates to the temperate ones. The results show a strong dependence of potential energy savings on Window-to-Wall Ratio (WWR) and solar irradiance on windows. In cooling dominated climates, the adoption of PVC windows has been demonstrated to be always beneficial, even with very low WWR and/or non-optimal exposures, achieving overall energy savings of up to 20%. In heating dominated climates, adoption of PVC windows should be carefully considered, as it is highly beneficial when large glazed surfaces are present. In this case annual total energy savings up to the 32% can be predicted in comparison with buildings equipped with standard clear windows
Nanotecnologie e nanodispositivi. Opportunità per involucri edilizi intelligenti ed efficienza energetica in edilizia
No full textSmart Materials and Devices for Energy Saving and Harvesting
Full text linkThe decarbonisation objectives set for 2050 compel us to envisage any effective strategy in order to reduce the human impact on the planet, drastically reducing greenhouse gas emissions to reduce the effects of global warming [...
Visual comfort assessment of smart photovoltachromic windows
No full textAn experimental study of photovoltachromic (PVCC) devices for dynamic solar control in buildings is presented. The fabricated devices underwent a complete opto-eletctrical characterization and the results obtained were employed as an input for the simulation of building integrated multifunctional windows. This multidisciplinary activity aims at achieving relevant feedbacks from the simulation of real large area devices in order to adjust and even direct further experimental efforts, before reaching the production phase. Devices having different electrochromic capacitances were used and the optical measurements became useful inputs for the simulation task. Simulation's results turned into feedbacks concerning the modulation of the transmittance spectra, the colour of bleached devices, the scale-up of PVCCs. Devices used in the current work showed a power peak of 4.22 mW/cm(2) at the maximum power point and a smart modulation of optical transmittance of 50.16% (at 700 nm). Simulations of natural light penetration in office buildings showed that the integration of PVCCs in traditional windows could dramatically increase indoor visual comfort. An increase of the average UDI for a typical room up to 71.8% and a decrease of intolerable glare levels (DGP higher than 0.45) down to 12% were the major benefits of the substitution of traditional clear glasses with integrated PVCCs. (C) 2013 Elsevier B.V. All rights reserved
Photovoltachromic device with interdigitated electrodes
No full textA photovoltachromic device (50) having a photoelectrode (86) and a counterelectrode (66), the counterelectrode including an electrochromic region (70) and a catalytic region (72) that are physically separate. The electrochromic region and the catalytic region are interdigitated
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