Solar Energy Absorbing Materials that are Capable of Withstanding Long-Term Exposure at 600 °C: Research Strategy

2018 ◽  
Vol 788 ◽  
pp. 126-134
Author(s):  
Ilona Pavlovska ◽  
Gundars Mežinskis ◽  
Laimons Paulis Bīdermanis

Pipes for parabolic-trough solar energy collectors (PTSC) must be able to operate and withstand high temperatures in corrosive environments for a long time without changing its microstructure and losing its original properties. The stages of development of a new material and technology for solar energy collectors that allows the production of a PTSC solar energy-absorbing material that is capable of withstanding temperatures ≥ 600 °C for at least 250 days are described. This material is a glass-crystalline enamel coating that is adhered to tubular stainless steel pipes. Such enamel coatings have high coefficients of thermal expansion (CTE) that are similar to the metal surface. These matching CTEs allow the enamel coatings to resist flaking during the heating at 900 °C. The high-temperature resistance of the developed coating was ensured not only by specific additives added to the frit of the coating but also by an additional nanosized sol-gel coating over the enamelled metal substrate.

2018 ◽  
Vol 35 ◽  
pp. 202-215
Author(s):  
Ilona Pavlovska ◽  
Gundars Mežinskis ◽  
Laimons-Paulis Bīdermanis

Darbā aprakstītas jauna materiāla un tehnoloģijas izstrādes stadijas saules enerģijas kolektoriem. Augstas jaudas saules enerģijas kolektora (AJSEK) cauruļveida materiālam jāspēj ilgstoši izturēt augstas temperatūras, neizmainot savu mikrostruktūru un nezaudējot savus sākotnējos siltumtehniskos raksturlielumus. RTU Silikātu materiālu institūta zinātnieki sadarbībā  ar LU Cietvielu fizikas institūta speciālistu izstrādājuši tehnoloģiju, kas ļauj iegūt AJSEK saules enerģiju uztverošu materiālu un spēj izturēt 600 °C temperatūru vismaz 250 dienas. Šī materiāla pamatā ir nerūsējošā tērauda cauruļveida iz- strādājums, kuram uzklāts stiklkristālisks emaljas pārklājums. Ilgstošu augsttemperatūras izturību nodrošina ne vien emaljas pārklājuma fritei pievienotās specifiskās piedevas, bet arī emaljai uzklātais sola-gēla nanodaļiņu pārklājums.Sol-gel coating on enamelled alloy steelThe stages of development of a new material and a technology for solar  collectors are described. Pipes for parabolic-trough solar collectors (PTSC) must be able to withstand high temperatures for a long time without changing their microstructure and losing their original thermal characteristics. The scientists from the Institute of Silicate Materials (Riga Technical University) together with a specialist from the Institute of Solid State Physics (University of Latvia) have developed a technology that allows the production of PTSC solar-absorbing materials capable of withstanding 600 °C temperatures for at least 250 days. This material is based on glass-crystalline enamel coating on tubular stainless steel pipes. The high-temperature resistance was ensured not only by specific additives added to the frit of enamel coating, but also by a nanosized sol-gel coating over the enamel.Keywords – enamel coatings for steel, sol-gel coatings, thermal properties, chemical properties, microhardness


Author(s):  
Tao Jia ◽  
Xue Han ◽  
Shen Meihua ◽  
Jing Liu ◽  
Zuoyu Wang ◽  
...  

Integrated water purification and electricity generation by photo-thermal effect has attracted great attention. However, the central issues are designs of the photothermal materials with efficient utilization of solar energy for...


2020 ◽  
Vol 64 (1-4) ◽  
pp. 1261-1268
Author(s):  
Shu Otani ◽  
Dang-Trang Nguyen ◽  
Kozo Taguchi

In this study, a portable and disposable paper-based microbial fuel cell (MFC) was fabricated. The MFC was powered by Rhodopseudomonas palustris bacteria (R. palustris). An activated carbon sheet-based anode pre-loaded organic matter (starch) and R. palustris was used. By using starch in the anode, R. palustris-loaded on the anode could be preserved for a long time in dry conditions. The MFC could generate electricity on-demand activated by adding water to the anode. The activated carbon sheet anode was treated by UV-ozone treatment to remove impurities and to improve its hydrophilicity before being loaded with R. palustris. The developed MFC could generate the maximum power density of 0.9 μW/cm2 and could be preserved for long-term usage with little performance degradation (10% after four weeks).


2019 ◽  
Author(s):  
Zhao-Yang Zhang ◽  
Tao LI

Solar energy and ambient heat are two inexhaustible energy sources for addressing the global challenge of energy and sustainability. Solar thermal battery based on molecular switches that can store solar energy and release it as heat has recently attracted great interest, but its development is severely limited by both low energy density and short storage stability. On the other hand, the efficient recovery and upgrading of low-grade heat, especially that of the ambient heat, has been a great challenge. Here we report that solar energy and ambient heat can be simultaneously harvested and stored, which is enabled by room-temperature photochemical crystal-to-liquid transitions of small-molecule photoswitches. The two forms of energy are released together to produce high-temperature heat during the reverse photochemical phase change. This strategy, combined with molecular design, provides high energy density of 320-370 J/g and long-term storage stability (half-life of about 3 months). On this basis, we fabricate high-performance, flexible film devices of solar thermal battery, which can be readily recharged at room temperature with good cycling ability, show fast rate of heat release, and produce high-temperature heat that is >20<sup> o</sup>C higher than the ambient temperature. Our work opens up a new avenue to harvest ambient heat, and demonstrate a feasible strategy to develop high-performance solar thermal battery.


2019 ◽  
Author(s):  
Zhao-Yang Zhang ◽  
Tao LI

Solar energy and ambient heat are two inexhaustible energy sources for addressing the global challenge of energy and sustainability. Solar thermal battery based on molecular switches that can store solar energy and release it as heat has recently attracted great interest, but its development is severely limited by both low energy density and short storage stability. On the other hand, the efficient recovery and upgrading of low-grade heat, especially that of the ambient heat, has been a great challenge. Here we report that solar energy and ambient heat can be simultaneously harvested and stored, which is enabled by room-temperature photochemical crystal-to-liquid transitions of small-molecule photoswitches. The two forms of energy are released together to produce high-temperature heat during the reverse photochemical phase change. This strategy, combined with molecular design, provides high energy density of 320-370 J/g and long-term storage stability (half-life of about 3 months). On this basis, we fabricate high-performance, flexible film devices of solar thermal battery, which can be readily recharged at room temperature with good cycling ability, show fast rate of heat release, and produce high-temperature heat that is >20<sup> o</sup>C higher than the ambient temperature. Our work opens up a new avenue to harvest ambient heat, and demonstrate a feasible strategy to develop high-performance solar thermal battery.


2017 ◽  
Vol 59 (1) ◽  
pp. 81-85
Author(s):  
Jianjun Zhang ◽  
Hao Zeng ◽  
Chun Liu ◽  
Chao Li ◽  
Sude Ma ◽  
...  

Author(s):  
Akil Ibrahim Al-Zuhari

The article defines the features of the process of forming the research tradition of studying the institute of parliamentarism as a mechanism for the formation of democracy. It is established that parliamentarism acts as one of the varieties of the regime of functioning of the state, to which the independence of the representative body from the people is inherent, its actual primacy in the state mechanism, the division of functions between the legislative and executive branches of government, the responsibility and accountability of the government to the parliament. It is justified that, in addition to the regime that fully meets the stated requirements of classical parliamentarism, there are regimes that can be characterized as limited parliamentary regimes. The conclusions point out that parliamentarism does not necessarily lead to a democracy regime. At the first stage of development of statehood, it functions for a long time in the absence of many attributes of democracy, but at the present stage, without parliamentarism, democracy will be substantially limited. Modern researchers of parliamentarism recognize that this institution is undergoing changes with the development of the processes of democracy and democratization. This is what produces different approaches to its definition. However, most scientists under classical parliamentarianism understand such a system, which is based on the balance of power. This approach seeks to justify limiting the rights of parliament and strengthening executive power. Keywords: Parliamentarism, research strategy, theory of parliamentarism, types of parliamentarism


Mediaevistik ◽  
2020 ◽  
Vol 32 (1) ◽  
pp. 11-53
Author(s):  
Bernard S. Bachrach

During the first thirty-three years of his reign as king of the Franks, i.e., prior to his coronation as emperor on Christmas day 800, Charlemagne, scholars generally agree, pursued a successful long-term offensive and expansionist strategy. This strategy was aimed at conquering large swaths of erstwhile imperial territory in the west and bringing under Carolingian rule a wide variety of peoples, who either themselves or their regional predecessors previously had not been subject to Frankish regnum.1 For a very long time, scholars took the position that Charlemagne continued to pursue this expansionist strategy throughout the imperial years, i.e., from his coronation on Christmas Day 800 until his final illness in later January 814. For example, Louis Halphen observed: “comme empereur, Charles poursuit, sans plus, l’oeuvre entamée avant l’an 800.”2 F. L. Ganshof, who also wrote several studies treating Charlemagne’s army, was in lock step with Halphen and observed: “As emperor, Charlemagne pursued the political and military course he had been following before 25 December 800.”3


1984 ◽  
Vol 16 (3-4) ◽  
pp. 623-633
Author(s):  
M Loxham ◽  
F Weststrate

It is generally agreed that both the landfill option, or the civil techniques option for the final disposal of contaminated harbour sludge involves the isolation of the sludge from the environment. For short time scales, engineered barriers such as a bentonite screen, plastic sheets, pumping strategies etc. can be used. However for long time scales the effectiveness of such measures cannot be counted upon. It is thus necessary to be able to predict the long term environmenttal spread of contaminants from a mature landfill. A model is presented that considers diffusion and adsorption in the landfill site and convection and adsorption in the underlaying aquifer. From a parameter analysis starting form practical values it is shown that the adsorption behaviour and the molecular diffusion coefficient of the sludge, are the key parameters involved in the near field. The dilution effects of the far field migration patterns are also illustrated.


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