Proceedings of the Fifth Italian Conference on Computational Linguistics CLiC-it 2018

On behalf of the Program Committee, a very warm welcome to the Fifth Italian Conference on Computational Linguistics (CLiC-­‐it 2018). This edition of the conference is held in Torino. The conference is locally organised by the University of Torino and hosted into its prestigious main lecture hall “Cavallerizza Reale”. The CLiC-­‐it conference series is an initiative of the Italian Association for Computational Linguistics (AILC) which, after five years of activity, has clearly established itself as the premier national forum for research and development in the fields of Computational Linguistics and Natural Language Processing, where leading researchers and practitioners from academia and industry meet to share their research results, experiences, and challenges

VO2 thermochromic metamaterial-based smart optical solar reflector

Optical solar reflector smart radiators are able to control the temperature of spacecraft. This work demonstrates a novel smart optical solar reflector using a patterned thermo-chromic VO2 plasmonic meta-surface design. The VO2 meta-surface combines the temperature induced phase transition of VO2 with plasmonic resonances resulting in a significant enhancement of the infrared absorption. The enhanced absorption obtained at a reduced VO2 coverage results in superior emittance tunability Δε and lower solar absorptance α compared to a corresponding thin-film reflector. An emittance tunability of 0.48 is obtained for the meta-reflector design, representing a 30% improvement compared to the unstructured film. Meta-surface based smart optical solar reflectors offer a new route toward energy-efficient and cost-effective passive thermal control systems of spacecraft and other surfaces

Dataset to support the journal article: VO2 Metasurface Smart Thermal Emitter with High Visual Transparency for Passive Radiative Cooling Regulation in Space and Terrestrial Applications

Simulation results and optical spectra of devices, the dataset consists of a single excel file with spreadsheet for each subfigure/figure presented in the paper</span

Dataset for VO2 thermo-chromic metamaterial-based smart optical solar reflector

Data supporting the paper: Sun, K., Riedel, C. A., Urbani, A., Simeoni, M., Mengali, S., Zalkovskij, M., ... Muskens, O. L. (2018). VO 2 Thermochromic Metamaterial-Based Smart Optical Solar Reflector. ACS Photonics. DOI: 10.1021/acsphotonics.8b00119</span

Metasurface optical solar reflectors using AZO transparent conducting oxides for radiative cooling of spacecraft

Optical solar reflectors are devices that combine high reflection for visible wavelengths with a strong emissivity in the infrared. Compared to the conventional rigid quartz tiles used on spacecraft since the 1960s, thin-film solutions can offer a significant advantage in weight, assembly, and launch costs. Here, we present a metasurface-based approach using an Al-doped ZnO (AZO) transparent conducting oxide as infrared plasmonic material. The AZO is patterned into a metasurface to achieve broad plasmonic resonances with an enhanced absorption of electromagnetic radiation in the thermal infrared. In the visible range, the transparent conducting oxide provides low losses for solar radiation, while intrinsic absorption losses in the ultraviolet range are effectively suppressed using a multilayer reflecting coating. The addition of high-emissivity layers to the stack eventually results in comparable emissivity values to the thin plasmonic device, thus defining a window of opportunity for plasmonic absorption as a design strategy for ultrathin devices. The optimized experimental structure achieves solar absorptance (α) of 0.16 and thermal emissivity (ε) of 0.79. Our first prototype demonstrator paves the way for further improvement and large-area fabrication of metasurface solar reflectors and ultimately their application in space missions

Passive thermal radiation control based on thermochromic W-doped VO2 metasurfaces

Radiative cooling becomes a popular research topic targeting an energy efficient solution for thermal management. Vanadium dioxide (VO2), as a thermochromic material, is able to switch optical property between dielectric and metallic states depending on its temperature. We present a passive thermal management solution through a VO2 based metasurface. Through a novel ALD process, the fabricated VO2 metasurface on polyimide substratehas a room-temperature transition and a high infrared emissivity of ~0.4

VO₂metasurface smart thermal emitter with high visual transparency for passive radiative cooling regulation in space and terrestrial applications

Smart radiative cooling devices based on thermochromic materials such as vanadium dioxide (VO2) are of practical interest for temperature regulation and artificial homeostasis, i.e., maintaining stable equilibrium conditions for survival, both in terrestrial and space applications. In traditional solar reflector configurations, solar absorption in the VO2 layer is a performance limiting factor due to the multiple reflections of sunlight in the stack. Here, we demonstrate a visually transparent, smart radiator panel with reduced solar absorption. An Al-doped ZnO transparent conducting oxide layer acts as a frequency selective infrared back-reflector with high transmission of solar radiation. In this study we make use of high-quality VO2 thin films deposited using atomic layer deposition and optimized annealing process. Patterning of the VO2 layer into a metasurface results in a further reduction of the solar absorption parameter α to around 0.3, while exhibiting a thermal emissivity contrast Δϵ of 0.26 by exploiting plasmonic enhancement effects. The VO2 metasurface provides a visual spectrum transmission of up to 62%, which is of interest for a range of applications requiring visual transparency. The transparent smart metasurface thermal emitter offers a new approach for thermal management in both space and terrestrial radiative cooling scenarios. </p