The Experts below are selected from a list of 130509 Experts worldwide ranked by ideXlab platform
Ekmel Ozbay - One of the best experts on this subject based on the ideXlab platform.
-
disordered and densely packed ito nanorods as an excellent lithography free optical solar reflector metasurface for the radiative cooling of spacecraft
Proceedings of SPIE Vol. 11080 Metamaterials Metadevices and Metasystems 2019, 2019Co-Authors: Deniz Umut Yildirim, Amir Ghobadi, Mahmut Can Soydan, Okan Atesal, Ahmet Toprak, Mehmet Deniz Caliskan, Ekmel OzbayAbstract:Optical Solar Reflectors (OSRs) form the Physical Interface between the spacecraft and space and they are essential for the stabilization and uniform distribution of temperature throughout the spacecraft. OSRs need to possess a spectrally selective response of broadband and perfect electromagnetic wave absorption in the thermal-infrared spectral range, while strongly reflecting the solar energy input. In this work, we experimentally show that disordered and densely packed ITO nanorod forests can be used as an excellent top-layer metasurface in a metal-insulator-oxide cavity configuration, and a thermal-emissivity of 0.97 is experimentally realized in the spectral range from 2.5 to 25 μm. The low-loss dielectric response of ITO in the solar spectrum, from 300 nm to 2.5 μm range limited the solar absorptivity to an experimental value of 0.167. These make our proposed design highly promising for its application in space missions due to combining high throughput, robustness, low cost with ultra-high performance.
-
Disordered and Densely Packed ITO Nanorods as an Excellent Lithography-Free Optical Solar Reflector Metasurface
ACS Photonics, 2019Co-Authors: Deniz Umut Yildirim, Amir Ghobadi, Mahmut Can Soydan, Okan Atesal, Ahmet Toprak, Mehmet Deniz Caliskan, Ekmel OzbayAbstract:Precise control and stabilization of the operating temperature environment of spacecraft and satellites during their life cycle is of paramount importance to increase device reliabilities and reduce the thermomechanical constraints. Optical solar reflectors are the Physical Interface between the spacecraft and space, and they are broadband mirrors for the solar spectrum, while having strong thermal emission in the mid-infrared part of the electromagnetic spectrum. Strong light–matter interactions in metamaterials and metasurfaces offer significant advantages compared to the conventional methods in performance, weight, launch, and assembly costs. However, the fabrication complexity of these metastructures due to necessitating lithography hinders their upscaling, reproducibility, large-area compatibility, and mass production. In this regard, we propose a facile, lithography-free fabrication route, exploiting oblique deposition to design a metasurface based on disordered and densely packed Indium Tin Oxide (...
Yuriy Serdyuk - One of the best experts on this subject based on the ideXlab platform.
-
space charge accumulation at material Interfaces in hvdc cable insulation part i experimental study and charge injection hypothesis
Energies, 2020Co-Authors: Espen Doedens, Markus E Jarvid, Raphael Guffond, Yuriy SerdyukAbstract:On-site installation of accessories on extruded polymeric high voltage cables in a common practice. The procedure requires the shaping of the Physical Interface between the cable insulation surface and the pre-molded accessory body. On such Interfaces, rough surfaces should be avoided in order to limit space charge accumulation in the insulation, which affects the cable performance by reducing insulation life-time, creating conditions for local field enhancement, and, respectively, the formation of possible breakdown path e.g. by electrical treeing. Space charge measurements on cable insulation peelings were undertaken to assess the space charge injection and accumulation on Interfaces with varying degrees of surface roughness in order to improve understanding on this subject. The results of the measurements confirm the hypothesis regarding the enhancement of charge injection from rough surfaces when electric field strength exceeds a certain level. The accumulated charge density in the material is shown to strongly depend on the field strength and temperature in both polarization and subsequent depolarization measurements. These results emphasize that a bipolar charge transport model that incorporates field and temperature dependencies of charge injection, trapping, detrapping, and recombination processes needs to be adopted to accurately describe the observed electric conduction phenomena.
Mingzhen Wei - One of the best experts on this subject based on the ideXlab platform.
-
Decoupling the Stationary Navier-Stokes-Darcy System with the Beavers-Joseph-Saffman Interface Condition
Abstract and Applied Analysis, 2013Co-Authors: Yong Cao, Yuchuan Chu, Mingzhen WeiAbstract:This paper proposes a domain decomposition method for the coupled stationary Navier-Stokes and Darcy equations with the Beavers-Joseph-Saffman Interface condition in order to improve the efficiency of the finite element method. The Physical Interface conditions are directly utilized to construct the boundary conditions on the Interface and then decouple the Navier-Stokes and Darcy equations. Newton iteration will be used to deal with the nonlinear systems. Numerical results are presented to illustrate the features of the proposed method.
Deniz Umut Yildirim - One of the best experts on this subject based on the ideXlab platform.
-
disordered and densely packed ito nanorods as an excellent lithography free optical solar reflector metasurface for the radiative cooling of spacecraft
Proceedings of SPIE Vol. 11080 Metamaterials Metadevices and Metasystems 2019, 2019Co-Authors: Deniz Umut Yildirim, Amir Ghobadi, Mahmut Can Soydan, Okan Atesal, Ahmet Toprak, Mehmet Deniz Caliskan, Ekmel OzbayAbstract:Optical Solar Reflectors (OSRs) form the Physical Interface between the spacecraft and space and they are essential for the stabilization and uniform distribution of temperature throughout the spacecraft. OSRs need to possess a spectrally selective response of broadband and perfect electromagnetic wave absorption in the thermal-infrared spectral range, while strongly reflecting the solar energy input. In this work, we experimentally show that disordered and densely packed ITO nanorod forests can be used as an excellent top-layer metasurface in a metal-insulator-oxide cavity configuration, and a thermal-emissivity of 0.97 is experimentally realized in the spectral range from 2.5 to 25 μm. The low-loss dielectric response of ITO in the solar spectrum, from 300 nm to 2.5 μm range limited the solar absorptivity to an experimental value of 0.167. These make our proposed design highly promising for its application in space missions due to combining high throughput, robustness, low cost with ultra-high performance.
-
Disordered and Densely Packed ITO Nanorods as an Excellent Lithography-Free Optical Solar Reflector Metasurface
ACS Photonics, 2019Co-Authors: Deniz Umut Yildirim, Amir Ghobadi, Mahmut Can Soydan, Okan Atesal, Ahmet Toprak, Mehmet Deniz Caliskan, Ekmel OzbayAbstract:Precise control and stabilization of the operating temperature environment of spacecraft and satellites during their life cycle is of paramount importance to increase device reliabilities and reduce the thermomechanical constraints. Optical solar reflectors are the Physical Interface between the spacecraft and space, and they are broadband mirrors for the solar spectrum, while having strong thermal emission in the mid-infrared part of the electromagnetic spectrum. Strong light–matter interactions in metamaterials and metasurfaces offer significant advantages compared to the conventional methods in performance, weight, launch, and assembly costs. However, the fabrication complexity of these metastructures due to necessitating lithography hinders their upscaling, reproducibility, large-area compatibility, and mass production. In this regard, we propose a facile, lithography-free fabrication route, exploiting oblique deposition to design a metasurface based on disordered and densely packed Indium Tin Oxide (...
Espen Doedens - One of the best experts on this subject based on the ideXlab platform.
-
space charge accumulation at material Interfaces in hvdc cable insulation part i experimental study and charge injection hypothesis
Energies, 2020Co-Authors: Espen Doedens, Markus E Jarvid, Raphael Guffond, Yuriy SerdyukAbstract:On-site installation of accessories on extruded polymeric high voltage cables in a common practice. The procedure requires the shaping of the Physical Interface between the cable insulation surface and the pre-molded accessory body. On such Interfaces, rough surfaces should be avoided in order to limit space charge accumulation in the insulation, which affects the cable performance by reducing insulation life-time, creating conditions for local field enhancement, and, respectively, the formation of possible breakdown path e.g. by electrical treeing. Space charge measurements on cable insulation peelings were undertaken to assess the space charge injection and accumulation on Interfaces with varying degrees of surface roughness in order to improve understanding on this subject. The results of the measurements confirm the hypothesis regarding the enhancement of charge injection from rough surfaces when electric field strength exceeds a certain level. The accumulated charge density in the material is shown to strongly depend on the field strength and temperature in both polarization and subsequent depolarization measurements. These results emphasize that a bipolar charge transport model that incorporates field and temperature dependencies of charge injection, trapping, detrapping, and recombination processes needs to be adopted to accurately describe the observed electric conduction phenomena.
