scholarly journals The Oxford space environment goniometer: A new experimental setup for making directional emissivity measurements under a simulated space environment

2017 ◽  
Vol 88 (12) ◽  
pp. 124502 ◽  
Author(s):  
T. J. Warren ◽  
N. E. Bowles ◽  
K. Donaldson Hanna ◽  
I. R. Thomas
Keyword(s):  
Space Environment ◽  
Experimental Setup ◽  
Directional Emissivity ◽  
Emissivity Measurements

scholarly journals c-Si PV cells emissivity characterization at low operating temperatures for efficiency management

2020 ◽  
Vol 307 ◽  
pp. 01044
Author(s):  
Raquel Fuente ◽  
Telmo Echániz ◽  
Iñigo González de Arrieta ◽  
Irene Urcelay-Olabarria ◽  
Manuel J. Tello ◽  
...  
Keyword(s):  
Solar Cell ◽  
Basque Country ◽  
Radiative Properties ◽  
Passive Cooling ◽  
Infrared Emissivity ◽  
Thermal Radiative Properties ◽  
Si Solar Cells ◽  
Directional Emissivity ◽  
The University ◽  
Emissivity Measurements

Efficiency is a critical parameter for a solar cell to be successful and is closely related to the working temperature of the cell. In turn, the temperature can be related to the infrared emissivity, the parameter that governs the thermal radiative properties of a body. In particular, the importance of infrared emissivity in a solar cell is essential in passive cooling applications, where controlled radiative thermal losses could let the cell operate at lower temperatures, the range where they present higher efficiency. In this presentation, the emissivity of c-Si solar cells in the low temperature range (around 50 ºC) is discussed. Traditionally, it has been determined by indirect reflectivity measurements at ambient temperature and extrapolated to working temperatures, but here, a direct measurement is proposed. For an accurate value the measurements are performed in the high accuracy radiometer of the University of the Basque Country, which allows spectral directional emissivity measurements as a function of temperature.

scholarly journals Evaluation of Six Directional Canopy Emissivity Models in the Thermal Infrared Using Emissivity Measurements

2019 ◽  
Vol 11 (24) ◽  
pp. 3011
Author(s):  
Lluís Pérez-Planells ◽  
Enric Valor ◽  
Raquel Niclòs ◽  
César Coll ◽  
Jesús Puchades ◽  
...  
Keyword(s):  
Land Surface ◽  
Thermal Infrared ◽  
Organic Soil ◽  
Area Index ◽  
Directional Emissivity ◽  
Reference Measurements ◽  
Emissivity Measurements ◽  
Single Set ◽  
Different Soils

Land surface temperature (LST) is a fundamental physical quantity in a range of different studies, for example in climatological analyses and surface–atmosphere heat flux assessments, especially in heterogeneous and complex surfaces such as vegetated canopies. To obtain accurate LST values, it is important to measure accurately the land surface emissivity (LSE) in the thermal infrared spectrum. In the past decades, different directional emissivity canopy models have been proposed. This paper evaluates six radiative transfer models (FR97, Mod3, Rmod3, 4SAIL, REN15, and CE-P models) through a comparison with in situ emissivity measurements performed using the temperature-emissivity separation (TES) method. The evaluation is done using a single set of rose plants over two different soils with very different spectral behavior. First, using an organic soil, the measurements were done for seven different observation angles, from 0° to 60° in steps of 10°, and for six different values of leaf area index (LAI). Taking into account all LAIs, the bias (and root mean square error, RMSE) obtained were 0.003 (±0.006), −0.004 (±0.005), −0.009 (±0.011), 0.005 (±0.007), 0.004 (±0.007), and 0.005 (±0.007) for FR97, Mod3, Rmod3, 4SAIL, REN 15, and CE-P models, respectively. Second, using an inorganic soil, the measurements were done for six different LAIs but for two different observation angles: 0° and 55°. The bias (and RMSE) obtained were 0.012 (±0.014), 0.004 (±0.007), −0.020 (±0.035), 0.016 (±0.017), 0.013 (±0.015), 0.013 (±0.015) and for FR97, Mod3, Rmod3, 4SAIL, REN15, and CE-P models, respectively. Overall, the Mod3 model appears as the best model in comparison to the TES emissivity reference measurements.

New experimental device for infrared spectral directional emissivity measurements in a controlled environment

2006 ◽  
Vol 77 (11) ◽  
pp. 113111 ◽  
Author(s):  
Leire del Campo ◽  
Raúl B. Pérez-Sáez ◽  
Xabier Esquisabel ◽  
Ignacio Fernández ◽  
Manuel J. Tello
Keyword(s):  
Experimental Device ◽  
Controlled Environment ◽  
Infrared Spectral ◽  
Directional Emissivity ◽  
Emissivity Measurements

Quantitative surface damage studies by H.R.E.M.

1989 ◽  
Vol 47 ◽  
pp. 632-633
Author(s):  
S. R. Singh ◽  
H. J. Fan ◽  
L. D. Marks
Keyword(s):  
Solar Wind ◽  
Quantitative Analysis ◽  
Surface Science ◽  
Surface Damage ◽  
Space Environment ◽  
Oxygen Desorption ◽  
The Past ◽  
Diffusion Controlled ◽  
Original Observation ◽  
Substantial Interest

Since the original observation that the surfaces of materials undergo radiation damage in the electron microscope similar to that observed by more conventional surface science techniques there has been substantial interest in understanding these phenomena in more detail; for a review see. For instance, surface damage in a microscope mimics damage in the space environment due to the solar wind and electron beam lithographic operations.However, purely qualitative experiments that have been done in the past are inadequate. In addition, many experiments performed in conventional microscopes may be inaccurate. What is needed is careful quantitative analysis including comparisons of the behavior in UHV versus that in a conventional microscope. In this paper we will present results of quantitative analysis which clearly demonstrate that the phenomena of importance are diffusion controlled; more detailed presentations of the data have been published elsewhere.As an illustration of the results, Figure 1 shows a plot of the shrinkage of a single, roughly spherical particle of WO3 versus time (dose) driven by oxygen desorption from the surface.

New Director Named for NOAA's Space Environment Center

Space Weather ◽  
2006 ◽  
Vol 4 (6) ◽  
pp. n/a-n/a
Author(s):  
Mohi Kumar
Keyword(s):  
Space Environment
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