scholarly journals Protection to thermal impact of solar radiation: evaluation of selected reflective fabrics

2021 ◽  
Vol 2 (2) ◽  
pp. 103-114
Author(s):  
Lennart Teunissen ◽  
Linda Plaude ◽  
Kaspar Jansen
Keyword(s):  
Solar Radiation ◽  
Prolonged Exposure ◽  
Infrared Light ◽  
Thermal Impact ◽  
Impact Reduction ◽  
Radiation Transmission ◽  
Protective Strategy ◽  
Lower Heat ◽  
And Control ◽  
White Control

Prolonged exposure to solar radiation can cause considerable heat stress. The application of reflective materials in garments or sunscreens is generally considered as an appropriate protective strategy. In this study, we aimed to compare a range of reflective and control fabrics on their ability to reduce the thermal impact of solar radiation. We evaluated 16 reflective and 5 control fabrics, varying in applicability for garments and/or sunscreens. Transmission of ultraviolet, visible light and infrared radiation was studied using artificial solar light. Thermal impact reduction was first studied using artificial infrared light and secondly using natural sunlight, measuring temperature right at the back and 10 cm behind the fabric after a 10-minute exposure. Most samples showed comparably low radiation transmission (<10%). However, substantially higher transmission was observed in perforated and mesh-like reflective fabrics, as well as light-colored controls and coldblack® treated fabric. This resulted in larger temperature increases at 10 cm behind the fabric (+1-4°C in sunlight). Contact temperature at the back of the black fabrics ended up higher than at the back of the reflective and white control fabrics (T: 5-10°C in sunlight), the latter two showing minor mutual differences (T<3°C). In conclusion, the reflective fabrics (excluding perforated, mesh and coldblack®) showed minor mutual differences, lower heat absorption than the black control fabrics and lower heat transmission than the white ones. The results suggest that reflective or white fabrics are preferable for most garment applications, while reflective or possibly black fabrics are preferable for sunscreen applications.

scholarly journals Integrated management of tough lovegrass (Eragrostis plana Nees): associating chemical control tools and plant physiology

2021 ◽  
Vol 51 (2) ◽  
Author(s):  
Eduardo Avelino Faleiro ◽  
Diego Martins Chiapinotto ◽  
Fabiane Pinto Lamego ◽  
Carlos Eduardo Schaedler ◽  
Eduardo Bohrer de Azevedo
Keyword(s):  
Solar Radiation ◽  
Integrated Management ◽  
Dry Mass ◽  
Radiation Factor ◽  
Factor B ◽  
Randomized Design ◽  
Completely Randomized Design ◽  
Factor C ◽  
Resource Conditions ◽  
And Control

ABSTRACT: The objective of the study was to evaluate the efficiency of herbicides use in the control of tough lovegrass according to the availability of solar radiation and the presence or absence of flooded. Two experiments were conducted in a completely randomized design, in a 2x2x4 and 2x2x5 factorial scheme, where factor A was equivalent to the environment (natural or reduced radiation); factor B to water condition (with a 2 cm flooded or without); and, factor C the herbicides: cyhalofop butyl (315 g ha-1), glyphosate (1080 g ha-1), cyhalofop butyl + glyphosate (315 g ha-1 + 1080 g ha-1) and control (without application) in the first experiment. In the second experiment, the herbicides used were cyhalofop butyl (315 g ha-1), glyphosate (1080 g ha-1), sethoxydim (184g ha-1), imazethapyr (106 g ha-1) and control (without application). Glyphosate efficiently controls plants of tough lovegrass with four tillers (>90%), being superior to cyhalofop, imazethapyr and sethoxydim; independently, of resource conditions. Reduction in the availability of solar radiation generates less shoot dry mass production from the weed, and improves the control only by imazethapyr and cyhalofop. In general, a flooded condition does not affect tough lovegrass control by herbicides.

scholarly journals Anthropocenic Limitations to Climate Engineering

Humanities ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 186 ◽  
Author(s):  
Jeroen Oomen
Keyword(s):  
Climate Change ◽  
Solar Radiation ◽  
Solar Radiation Management ◽  
Climate Engineering ◽  
Engineering Research ◽  
Future Experimentation ◽  
Fundamental Objection ◽  
Climatic System ◽  
Radiation Management ◽  
And Control

The development of climate engineering research has historically depended on mostly western, holistic perceptions of climate and climate change. Determinations of climate and climate change as a global system have played a defining role in the development of climate engineering. As a result, climate engineering research in general, and solar radiation management (SRM) in particular, is primarily engaged in research of quantified, whole-Earth solutions. I argue that in the potential act of solar radiation management, a view of climate change that relies on the holistic western science of the climatic system is enshrined. This view, dependent on a deliberative intentionality that seems connected to anthropocenic notions of responsibility and control, profoundly influences the assumptions and research methods connected to climate engineering. While this may not necessarily be to the detriment of climate engineering proposals—in fact, it may be the only workable conception of SRM—it is a conceptual limit to the enterprise that has to be acknowledged. Additionally, in terms of governance, reliability, and cultural acceptance, this limit could be a fundamental objection to future experimentation (or implementation).

scholarly journals Design of Transparent Metasurfaces Based on Asymmetric Nanostructures for Directional and Selective Absorption

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3751
Author(s):  
Dong Wu ◽  
Yang Meng ◽  
Chang Liu
Keyword(s):  
Solar Radiation ◽  
Energy Saving ◽  
Noble Metals ◽  
Near Infrared ◽  
Low Cost ◽  
Infrared Light ◽  
Manufacturing Cost ◽  
Selective Absorption ◽  
Metal Insulator Metal ◽  
Peak Value

Maximizing the solar heat gain through windows in winter and minimizing the solar radiation entering the room in summer are of great significance for the energy saving of buildings. Here, we present a new idea for transparent metasurfaces, based on asymmetric metal/insulator/metal (MIM) nanostructures, which can be switched back and forth between absorbing and reflecting solar radiation by reversing the sample orientation. Owing to the fundamental mode of a low-quality-factor resonance, a selective near-infrared absorption is obtained with an absorption peak value of 90% upon front illumination. The average solar absorption (45%) is about 10% higher than that (35%) of reported transparent absorbers. The near-infrared light is also strongly and selectively reflected upon back illumination and a reflection peak value above 70% is observed. Meanwhile, the average visible transmission of the metasurface is above 60%, which is about 1.6 times that (36%) of previous transparent metasurface absorbers. In addition, Cu material can replace the noble metals in this work, which will greatly reduce the manufacturing cost. Owing to the attractive properties of directional and selective absorption, passive operation mode, and low cost of the materials, the metasurfaces have promising prospects in building energy saving or other solar applications where surface transparency is desirable.

scholarly journals Predicting the Cooling Potential of Different Shading Methods for Greenhouses in Arid Regions

Energies ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4716 ◽  
Author(s):  
Ahmed Abdel-Ghany ◽  
Ibrahim Al-Helal ◽  
Fahad Alkoaik ◽  
Abdullah Alsadon ◽  
Mohamed Shady ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Air Temperature ◽  
Arid Regions ◽  
Radiation Flux ◽  
Cooling Effect ◽  
Plastic Film ◽  
Solar Radiation Flux ◽  
Slaked Lime ◽  
Radiation Transmission

Shading greenhouses in a hot and sunny climate is essential to reduce the inside greenhouse air temperature. However, the type and location of nets need to be addressed properly to determine the shading method that provides a better cooling effect on the greenhouse air. This study was conducted to evaluate the effects of five different shading methods on greenhouse microclimates, and to investigate the cooling potential of each method. Four greenhouse models covered with 200-µm thick plastic film were used for the study: one was kept as control (C), one was whitened with slaked lime (L), and two were shaded with white and black nets (50% shading factor) deployed simultaneously at two locations, in contact (WC, BC) and at 20-cm distance from the cladding film (WD, BD). The microclimatic parameters were measured inside and outside the greenhouse models, and the cooling potential (CP) was predicted for each shading method. The results showed that the black net at 20-cm distance (BD) is desirable as it provides high CP with a reasonable solar radiation transmission. The maximum CP was estimated as 8.5 °C, 8 °C, 6 °C, 3.2 °C, and 2.1 °C for L, BD, BC, WD, and WC, respectively. Shading with white nets is not recommended because their cooling potential is very low. Based on these results, we developed correlations for predicting the CP for each shading method as a function of the transmitted solar radiation flux (Si). These correlations depend on Si. Accordingly, they can be used for small greenhouses, whitewashed with a slaked lime of any concentration, or shaded with a black net having any shading factor.

A Study of Direct Solar Radiation Transmission in Asymmetrical Multi-span Greenhouses using Scale Models and Simulation Models

2004 ◽  
Vol 88 (2) ◽  
pp. 243-253 ◽  
Author(s):  
T. Soriano ◽  
J.I. Montero ◽  
M.C. Sánchez-Guerrero ◽  
E. Medrano ◽  
A. Antón ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Simulation Models ◽  
Direct Solar Radiation ◽  
Scale Models ◽  
Radiation Transmission

scholarly journals Iontophoresis: principles and applications

2014 ◽  
Vol 27 (3) ◽  
pp. 469-481 ◽  
Author(s):  
Eddy Krueger ◽  
José Luiz Claudino Junior ◽  
Eduardo Mendonça Scheeren ◽  
Eduardo Borba Neves ◽  
Eduardo Mulinari ◽  
...  
Keyword(s):  
Soft Tissues ◽  
Prolonged Exposure ◽  
Electrical Current ◽  
Skin Layer ◽  
Google Scholar ◽  
Noninvasive Technique ◽  
Transdermal Penetration ◽  
And Control ◽  
Methods Of Treatment ◽  
Topical Applications

Introduction Iontophoresis is a noninvasive technique used to increase transdermal penetration of substances through the skin layer (epidermis, dermis and hypodermis) in a controlled manner. Technological advance in recent decades have provided reduced cost of equipment needed for implementation, which allowed for the expansion of this technique. Objective The aim of this paper is to present the state of the art on iontophoresis, ranging from the atomic characteristics of the ion formation to the current applications of the technique. Methods Were researched papers from databases: IOP publishing, ScienceDirect, Pubmed, Springer, IEEE Xplore, Google Scholar and books with keywords iontophoresis, ions, topical applications between 1967 and 2010. Results Were selected (number of papers and database) 1 IOP Publishing, 1 from ScienceDirect, Central, 1 from Springer, 2 from PubMed, 11 from IEEE Xplore, 35 from Google Scholar, and 15 books, totaling 66 references and websites with nationally marketed electrotherapy products. Conclusion Iontophoresis is suitable for applications such as acetic acid (calcific tendinitis and myositis ossificans), calcium chloride and magnesium sulfate (control of musculoskeletal spasms), dexamethasone (inflammation), lidocaine (inflammation of soft tissues), zinc oxide (rheumatoid arthritis). It is also used in cosmetic applications with devices attached to the skin and for eye treatment aimed at specific tissues of the eye, providing a treatment option for various eye diseases, reducing the complications secondary to traditional methods of treatment. The advantages are the significant increase in the release and control of therapeutic agents, including drugs with high molecular weight. The disadvantages of iontophoresis are the complexity of the drug release system and prolonged exposure of the skin to an electrical current.

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