Direct Irradiation Absorption by Nanofluids: A Proposal of Standardization by the Use of the 'Solar Wall'

2021 ◽  
Author(s):  
Ricardo José Pontes Lima ◽  
Juarez Pompeu de Amorim Neto ◽  
Paulo Alexandre Rocha ◽  
Stéphano Praxedes Mendonça ◽  
Maria Eugênia Vieira da Silva
Keyword(s):  
Direct Irradiation ◽  
Solar Wall

Numerical investigations of wind and thermal environment in 2D scaled street canyons with various aspect ratios and solar wall heating

2021 ◽  
Vol 190 ◽  
pp. 107525
Author(s):  
Lan Chen ◽  
Jian Hang ◽  
Guanwen Chen ◽  
Shanhe Liu ◽  
Yuanyuan Lin ◽  
...  
Keyword(s):  
Thermal Environment ◽  
Street Canyons ◽  
Numerical Investigations ◽  
Aspect Ratios ◽  
Wall Heating ◽  
Solar Wall

scholarly journals Effects of Temperature and Host Concentration on the Supramolecular Enantiodifferentiating [4 + 4] Photodimerization of 2-Anthracenecarboxylate through Triplet-Triplet Annihilation Catalyzed by Pt-Modified Cyclodextrins

Molecules ◽  
2019 ◽  
Vol 24 (8) ◽  
pp. 1502 ◽  
Author(s):  
Ming Rao ◽  
Wanhua Wu ◽  
Cheng Yang
Keyword(s):  
Light Emitting Diode ◽  
Temperature Dependency ◽  
Light Emitting ◽  
Modified Cyclodextrins ◽  
Direct Irradiation ◽  
Visible Light Driven ◽  
Significant Temperature ◽  
Effects Of Temperature ◽  
532 Nm ◽  
Triplet Triplet Annihilation

Visible-light-driven photocatalytic supramolecular enantiodifferentiating dimerization of 2-anthracenecarboxylic acid (AC) through triplet-triplet annihilation (TTA), mediated by the Schiff base Pt(II) complex (Pt-1, Pt-2, and Pt-3) was studied. The host concentration and the temperature effects on the stereoselectivity were comprehensively investigated. Increasing the concentration of sensitizers/hosts significantly enhanced the conversion of the photoreaction but led to reduced enantioselectivities of the chiral photodimers 2 and 3 when the photoreaction was triggered by a 532 nm laser, which was in contrast with the results obtained by direct irradiation of AC with a 365 nm light-emitting diode (LED) lamp, due to the aggregation of the sensitizer/host in water. The cyclization of AC through triplet-triplet annihilation displayed significant temperature dependency when Pt-3 was employed as the sensitizer/host. Increasing the temperature from 0 °C to 30 °C with 5% equiv. of Pt-3 led to a great increase of the ee of 2 from 2.1% to 31.6%. However, hardly any temperature dependency was observed when the photodimerization was mediated by other sensitizers and/or hosts, or the photoreaction was triggered directly with a 365 nm LED lamp.

Annual performance analysis of a dual-air-channel solar wall system with phase change material in different climate regions of China

Energy ◽  
2021 ◽  
pp. 121359
Author(s):  
Wei Ke ◽  
Jie Ji ◽  
Lijie Xu ◽  
Hao Xie ◽  
Chuyao Wang ◽  
...  
Keyword(s):  
Performance Analysis ◽  
Phase Change ◽  
Phase Change Material ◽  
Air Channel ◽  
Solar Wall ◽  
Change Material ◽  
Wall System

ENHANCING THERMAL COMFORT OF RESIDENTIAL BUILDINGS THROUGH A DUAL FUNCTIONAL PASSIVE SYSTEM (SOLAR-WALL)

2021 ◽  
Vol 16 (3) ◽  
pp. 155-177
Author(s):  
Shouib Mabdeh ◽  
Tamer Al Radaideh ◽  
Montaser Hiyari
Keyword(s):  
Thermal Comfort ◽  
Residential Buildings ◽  
Simulation Software ◽  
Design Parameters ◽  
Base Case ◽  
Passive System ◽  
Efficient System ◽  
Dual Functional ◽  
Solar Wall ◽  
New System

ABSTRACT Thermal comfort has a great impact on occupants’ productivity and general well-being. Since people spend 80–90% of their time indoors, developing the tools and methods that enhance the thermal comfort for building are worth investigating. Previous studies have proved that using passive systems like Trombe walls and solar chimneys significantly enhanced thermal comfort in inside spaces despite that each system has a specific purpose within a specific climate condition. Hence, the main purpose of this study is to design and configure a new, dual functional passive system, called a solar wall. The new system combines the Trombe wall and solar chimney, and it can cool or heat based on building needs. Simulation software, DesignBuilder, has been used to configure the Solar Wall, and study its impact on indoor operative temperature for the base case. Using the new system, the simulation results were compared with those obtained in the base case and analyzed to determine the most efficient system design parameters and implementation method. The case that gave the best results for solar wall configuration was triple glazed glass and 0.1 cm copper as an absorber (case 11). The results show that using four units (case D) achieves longer thermal comfort levels: 15 to 24 thermal hours during winter (compared to five hours maximum) and 10 to 19 comfort hours in summer (compared to zero).

ENHANCING THERMAL COMFORT OF RESIDENTIAL BUILDINGS THROUGH DUAL FUNCTIONAL PASSIVE SYSTEM (SOLAR-WALL)

2021 ◽  
Vol 16 (1) ◽  
pp. 139-161
Author(s):  
Shouib Mabdeh ◽  
Tamer Al Radaideh ◽  
Montaser Hiyari
Keyword(s):  
Thermal Comfort ◽  
Residential Buildings ◽  
Simulation Software ◽  
Design Parameters ◽  
Base Case ◽  
Passive System ◽  
Efficient System ◽  
Dual Functional ◽  
Solar Wall ◽  
New System

ABSTRACT Thermal comfort has a great effect on occupants’ productivity and general well-being. Since people spend 80–90% of their time indoors, developing the tools and methods that help in enhancing the thermal comfort for buildings are worth investigating. Previous studies have proved that using passive systems like Trombe walls and solar chimneys significantly enhanced thermal comfort in inside spaces despite that each system has a specific purpose within a specific climate condition. Hence, the main purpose of this study is to design and configure a new dual functional passive system, called a solar wall. The new system combines the Trombe wall and solar chimney, and it can cool or heat based on building needs. Simulation software, DesignBuilder, has been used to configure the Solar Wall and study its impact on indoor operative temperature for the base case. Using the new system, the simulation results were compared with those obtained in the base case and analyzed to determine the most efficient system design parameters and implementation method. The case that gave the best results for solar wall configuration was triple glazed glass and 0.1 cm copper as an absorber (case 11). The results show that using four units (case D) achieves longer thermal comfort levels: 15 to 24 thermal hours during winter (compared to five hours maximum) and 10 to 19 comfort hours in summer (compared to zero).

scholarly journals Optical and Electrical Properties of Gold-Silver Nanoalloys Synthesized through Photochemical Reduction using Femtosecond Laser

2020 ◽  
Vol 9 (3) ◽  
pp. 177-184
Author(s):  
Affi Nur Hidayah ◽  
◽  
Yuliati Herbani ◽  
Keyword(s):  
Electrical Properties ◽  
Femtosecond Laser ◽  
Au Nanoparticles ◽  
Volume Fraction ◽  
Conductivity Measurement ◽  
Silver Ions ◽  
Optical And Electrical Properties ◽  
Photochemical Reduction ◽  
Direct Irradiation ◽  
Gold Silver

In this work we investigated the optical and electrical properties of Au-Ag nanoalloys in various volume ratios. The nanoparticles have been prepared from gold and silver ions reduced by direct irradiation femtosecond laser. The samples were added into a quartz cuvette and irradiated for 10 minutes. Each sample was observed the optical property where surface plasmon resonance (SPR) peak was existed. In addition, electrical conductivity of the colloids was derived from the measurement of the correspond zeta potential by dynamic light scattering (DLS) method. The results showed that the SPR peak of Au-Ag nanoalloy were shifted almost linearly in between 409 nm for Ag and 530 nm for Au depending on their volume fraction. The conductivity measurement showed that Au0Ag100 (pure Ag) nanoparticles has the highest value and Au100Ag0 (pure Au) nanoparticles has the lowest value, and interestingly, Au-Ag nanoalloys have the values between Au0Ag100 and Au100Ag0. Briefly, this work revealed that both optical and electrical properties of Au-Ag nanoalloys can be easily tuned by regulating the volume fraction between the two elements.

The photochemistry of 5-cyano-2,3-benzobicyclo[4.2.0]octa-2,4,7-triene

1989 ◽  
Vol 67 (1) ◽  
pp. 82-87 ◽  
Author(s):  
Christopher Owen Bender ◽  
Douglas Dolman
Keyword(s):  
Excited State ◽  
Triplet Excited State ◽  
Deuterium Labelling ◽  
Direct Irradiation ◽  
Rearrangement Mechanism

The direct irradiation of 5-cyano-2,3-benzobicyclo[4.2.0]octa-2,4,7-triene (18) led to 6-cyanobenzocyclooctatetraene (17; Φ = 0.00075), 6-cyanobenzosemibullvalene (14; Φ = 0.0003), and 2-cyanonaphthalene (Φ = 0.00015). The triplet excited state of 18, generated by sensitization with a variety of ketone sensitizers (e.g., Michler's ketone and acetophenone), showed no unimolecular reactivity. Compound 18 does not participate in Zimmerman di-π-methane rearrangement; the potential product from such a transformation, 8-cyanobenzosemibullvalene (19), was, however, isolated from direct (Corex filter; Φ = 0,0010) irradiation of the semibullvalene 14. Deuterium labelling experiments suggest that 14 derives from a mechanism involving initial C4—C8 bonding of 18, and that cyclooctatetraene 17 is probably formed by simple electrocyclic opening of the cyclobutene ring of 18. Keywords: photochemistry, rearrangement mechanism, di-π-methane, semibullvalenes.

The Characteristics of Porous Solar Wall Heating System with Localized UFAD

2012 ◽  
Vol 178-181 ◽  
pp. 237-243
Author(s):  
Li Ouyang ◽  
Wei Liu
Keyword(s):  
Heat Transfer ◽  
Porous Medium ◽  
Saturated Porous Medium ◽  
Flow Characteristics ◽  
Heating System ◽  
Physical Models ◽  
Air Distribution ◽  
Cable System ◽  
Wall Heating ◽  
Solar Wall

In this paper, the physical models of the porous solar wall heating system with localized underfloor air distribution (UFAD) are established. Based on Brinkman-Forchheimer Extended Darcy and energy two-equation models for saturated porous medium, the influences of the structure of underfloor space on the heat transfer and flow characteristics of the system are simulated, analyzed and compared.The results show that the underfloor space with rational partition is good for improving the heat transfer and flow characteristics of system, and maintaining the cable system in the underfloor space.

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