scholarly journals Issue of heat mirror films overheating

2021 ◽  
Vol 345 ◽  
pp. 00025
Author(s):  
Václav Pospíšilík ◽  
Stanislav Honus
Keyword(s):  
Optical Properties ◽  
Thermal Stress ◽  
Energy Balance ◽  
Solar Radiation ◽  
Surface Temperature ◽  
Spectroscopic Measurement ◽  
Plastic Films ◽  
Thin Plastic

The study focuses on the issue of coated thin plastic films overheating due to the absorption of solar radiation. These films are suspended within the sealed space of dual-pane insulating glass units (IGU). Films are deformed due to thermal stress and the glazing ceases to carry out its function. The surface temperature of the glazing system was evaluated from energy balance during a sunny day. It was supposed the intensity of solar radiation 1000 W/m2. Solar radiation incidents perpendicular to the surface of the glazing. Spectroscopic measurement was performed and optical properties of glasses and films were evaluated. Finally, suitable glazing was designed, which partially prevents transmission of the solar radiation into the inner space of glazing and the thin plastic films are not significantly overheated.

scholarly journals A simple explanation for the sensitivity of the hydrologic cycle to global climate change

2013 ◽  
Vol 4 (2) ◽  
pp. 853-868 ◽  
Author(s):  
A. Kleidon ◽  
M. Renner
Keyword(s):  
Energy Balance ◽  
Solar Radiation ◽  
Surface Energy ◽  
Surface Temperature ◽  
Greenhouse Effect ◽  
Surface Energy Balance ◽  
Hydrologic Cycle ◽  
Maximum Power ◽  
Solar Radiation Management ◽  
Simple Explanation

Abstract. The global hydrologic cycle is likely to increase its strength with global warming. Climate models generally predict an increase in strength of 2.2% K−1, which is much weaker than what would be expected from the increase in saturation vapor pressure of 6.5% K−1. Furthermore, it has been reported that the sensitivity of the hydrologic cycle to surface temperature differences caused by solar radiation is about 50% greater than by an equivalent difference induced by the greenhouse effect. Here we show that these sensitivities can be derived analytically from an extremely simple surface energy balance model that is constrained by the assumption that vertical convective transport within the atmosphere operates at maximum power. Using current climatic mean conditions, this model predicts a sensitivity of the hydrologic cycle of 2.2% K−1 to surface temperature induced by differences in the greenhouse effect, and a sensitivity of 3.2% K−1 for differences caused by absorbed solar radiation. These sensitivities can be explained by considering the changes in the surface energy balance in which the heating by solar radiation is partitioned equally into radiative and turbulent cooling at a state of maximum power of convective exchange. This explanation emphasizes the different roles that solar and terrestrial radiation play in the surface energy balance and hydrologic cycling that cannot be lumped together into a radiative forcing concept. We illustrate one implication of this explanation for the case of geoengineering, which aims to undo surface temperature differences by solar radiation management, but will nevertheless result in substantial differences in hydrologic cycling due to the difference in sensitivities. We conclude that the overall sensitivity of the hydrologic cycle to surface temperature can be understood and predicted by very simple physical considerations.

Physical and Optical Properties of The Films Ð’i2Te3-Bi2Se3

2015 ◽  
Vol 11 (2) ◽  
pp. 3017-3022
Author(s):  
Gurban Akhmedov
Keyword(s):  
Thin Film ◽  
Optical Properties ◽  
Surface Temperature ◽  
Thermal Evaporation ◽  
Low Voltage ◽  
Internal Surface ◽  
Differential Resistance ◽  
Work Cycle

Results of researches show, that film p-n the structures received by a method of discrete thermal evaporation in a uniform work cycle, are suitable for use in low-voltage devices.  As a result of work are received p-n heterojunctions in thin-film execution, described by high values of differential resistance. Show that, thermo endurance - T0 maybe using as characteristic of thermo endurance of optic materials. If heating flow, destruction temperature and internal surface temperature is measured during test, it is possible to determine value T0 and other necessity characteristics. As a result of the taking test was lead to comparison evaluation of considered materials. Working range of heating flow and up level heating embark have been determined.

scholarly journals Impact of solar radiation and environmental temperature on Art Nouveau glass windows

2019 ◽  
Vol 7 (1) ◽  
Author(s):  
Teresa Palomar ◽  
Miguel Silva ◽  
Marcia Vilarigues ◽  
Isabel Pombo Cardoso ◽  
David Giovannacci
Keyword(s):  
Chemical Composition ◽  
Solar Radiation ◽  
Surface Temperature ◽  
Environmental Temperature ◽  
Summer Solstice ◽  
Art Nouveau ◽  
Ir Thermography ◽  
Hot Air ◽  
Near Ir ◽  
Air Pocket

Abstract This work presents the results of the evaluation of two Art Nouveau glass windows from the Casa-Museu Dr. Anastácio Gonçalves (Lisbon, Portugal) with IR-thermography during the summer solstice. According to the measurements, the surface temperature of glass depended on the outdoor environmental temperature and, mainly, on the direct solar radiation. Colored glasses presented a higher surface temperature due to the absorption of their chromophores at near-IR wavelengths. Enamels and grisailles showed higher surface temperatures than their support glasses due to both their chemical composition and color. The protective glazing, with small slits in one of the window panels, induced a hot-air pocket in its upper part due to the insufficient ventilation.

scholarly journals The Effects of Roadside Woody Vegetation on the Surface Temperature of Cycle Paths

Land ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 483
Author(s):  
Nikola Žižlavská ◽  
Tomáš Mikita ◽  
Zdeněk Patočka
Keyword(s):  
Solar Radiation ◽  
Surface Temperature ◽  
Well Being ◽  
Road Surface ◽  
Woody Vegetation ◽  
Surface Model ◽  
Main Hypothesis ◽  
Roadside Vegetation ◽  
Different Types ◽  
Aerial Vehicle

The article is on the effects of woody vegetation growing on the roadside on the temperature of the surface of cycle paths. The main hypothesis of the study is that vegetation has the effect of lowering the temperature of the surroundings in its shadow and thus improves the comfort of users of cycle paths in the summer months. The second hypothesis is to find out which type of road surface is most suitable for the thermal well-being of users. This goal was achieved by measuring the temperature of selected locations on cycle paths with different types of construction surfaces with nearby woody vegetation using a contactless thermometer over several days at regular intervals. The positions of the selected locations were measured using GNSS and the whole locality of interest was photographed using an unmanned aerial vehicle (UAV), or drone, and subsequently a digital surface model (DSM) of the area was created using a Structure from Motion (SfM) algorithm. This model served for the calculation of incident solar radiation during the selected days using the Solar Area Graphics tool with ArcGIS software. Subsequently, the effect of the shade of the surrounding vegetation on the temperature during the day was analysed and statistically evaluated. The results are presented in many graphs and their interpretation used to evaluate the effects of nearby woody vegetation and the type of road surface on the surrounding air temperature and the comfort of users of these routes. The results demonstrate the benefits of using UAVs for the purpose of modelling the course of solar radiation during the day, showing the effect of roadside vegetation on reducing the surface temperature of the earth’s surface and thus confirming the need for planting and maintaining such vegetation.

scholarly journals Potential of a Spectroscopic Measurement Method Using Adding–Doubling to Retrieve the Bulk Optical Properties of Dense Microalgal Media

2014 ◽  
Vol 68 (10) ◽  
pp. 1154-1167 ◽  
Author(s):  
Sarah Bellini ◽  
Ryad Bendoula ◽  
Eric Latrille ◽  
Jean-Michel Roger
Keyword(s):  
Optical Properties ◽  
Measurement Method ◽  
Spectroscopic Measurement

scholarly journals Shallow groundwater effect on land surface temperature and surface energy balance under bare soil conditions: modeling and description

2012 ◽  
Vol 16 (7) ◽  
pp. 1817-1831 ◽  
Author(s):  
F. Alkhaier ◽  
G. N. Flerchinger ◽  
Z. Su
Keyword(s):  
Energy Balance ◽  
Surface Temperature ◽  
Land Surface ◽  
Shallow Groundwater ◽  
Bare Soil ◽  
Heat Fluxes ◽  
Shortwave Radiation ◽  
Soil Conditions ◽  
Potential Evaporation ◽  
Available Energy

Abstract. Understanding when and how groundwater affects surface temperature and energy fluxes is significant for utilizing remote sensing in groundwater studies and for integrating aquifers within land surface models. To investigate the shallow groundwater effect under bare soil conditions, we numerically exposed two soil profiles to identical metrological forcing. One of the profiles had shallow groundwater. The different responses that the two profiles manifested were inspected regarding soil moisture, temperature and energy balance at the land surface. The findings showed that the two profiles differed in three aspects: the absorbed and emitted amounts of energy, the portioning out of the available energy and the heat fluency in the soil. We concluded that due to their lower albedo, shallow groundwater areas reflect less shortwave radiation and consequently get a higher magnitude of net radiation. When potential evaporation demand is sufficiently high, a large portion of the energy received by these areas is consumed for evaporation. This increases the latent heat flux and reduces the energy that could have heated the soil. Consequently, lower magnitudes of both sensible and ground heat fluxes are caused to occur. The higher soil thermal conductivity in shallow groundwater areas facilitates heat transfer between the top soil and the subsurface, i.e. soil subsurface is more thermally connected to the atmosphere. For the reliability of remote sensors in detecting shallow groundwater effect, it was concluded that this effect can be sufficiently clear to be detected if at least one of the following conditions occurs: high potential evaporation and high contrast between day and night temperatures. Under these conditions, most day and night hours are suitable for shallow groundwater depth detection.

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