Photothermal Energy Conversion Enhancement Studies Using Low Concentration Nanofluids

2019 ◽  
Vol 141 (6) ◽  
Author(s):  
P. Kalidoss ◽  
S. Venkatachalapathy ◽  
S. Suresh
Keyword(s):  
Base Fluid ◽  
Glass Tube ◽  
Fresnel Lens ◽  
Copper Tube ◽  
Visible Range ◽  
Fluid Temperature ◽  
Experimental Facility ◽  
Multiwalled Carbon ◽  
Energy Line

The present study aims to develop a compact experimental facility to trap solar energy. Line focusing concentrators, i.e., Fresnel lens and secondary reflectors, are coupled to enhance the photothermal conversion efficiency. Two types of receiver tubes are used, a plain copper tube and an evacuated glass tube embedded with a copper tube. Surfactant-free multiwalled carbon nanotubes–Therminol55 nanofluid with concentrations of 25, 50, 75, and 100 ppm are used in this study. The characterization of the nanoparticles and nanofluids is presented. In the visible range, a maximum absorbance and extinction coefficient of 0.75 and 1.7 cm−1 are obtained for 100 ppm concentration. The thermal conductivity is also enhanced by 6.29% compared to base fluid. A maximum fluid temperature of 78.15 and 89.58 °C is observed for plain receiver tube and receiver tube in evacuated space, respectively, and the corresponding efficiencies are 12.65 and 17.36%

Characterization of Temperature Dependence of Interfacial Tension and Viscosity of Nanofluid

2008 ◽  
Author(s):  
S. M. Sohel Murshed ◽  
Nam-Trung Nguyen
Keyword(s):  
Surface Tension ◽  
Interfacial Tension ◽  
Temperature Dependence ◽  
Base Fluid ◽  
Deionized Water ◽  
Fluid Temperature ◽  
Interfacial Tensions ◽  
Increasing Temperature ◽  
Reduced Surface

Investigations on temperature dependence of surface tension, interfacial tension and viscosity a nanofluid are reported in this paper. Experimental results show that nanofluid having TiO2 nanoparticles (15 nm) in deionized water exhibit substantially smaller surface tension and oil-based interfacial tension than those of the base fluid (i.e. deionized water). These surface and interfacial tensions of this nanofluid were found to decrease almost linearly with increasing temperature. The Brownian motion of nanoparticles in base fluid was identified as a possible mechanism for reduced surface and interfacial tensions of nanofluid. The measured effective viscosity of nanofluid was found to be insignificantly higher than that of base fluid and it also decreases with increasing fluid temperature.

Broadband Electrical Characterization of Multiwalled Carbon Nanotubes and Contacts

Nano Letters ◽  
2007 ◽  
Vol 7 (4) ◽  
pp. 1086-1090 ◽  
Author(s):  
Paul Rice ◽  
T. Mitch Wallis ◽  
Stephen E. Russek ◽  
Pavel Kabos
Keyword(s):  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Electrical Characterization ◽  
Multiwalled Carbon

scholarly journals Synthesis and Physicochemical Characterization of Multiwalled Carbon Nanotubes/Hydroxamic Alginate Nanocomposite Scaffolds

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Aline Margarete Furuyama Lima ◽  
Marcelo de Freitas Lima ◽  
Odílio Benedito Garrido Assis ◽  
Alice Raabe ◽  
Hemelen Caroline Amoroso ◽  
...  
Keyword(s):  
Concentration Level ◽  
Physicochemical Characterization ◽  
Physical And Mechanical Properties ◽  
L929 Cell ◽  
Multiwalled Carbon ◽  
Amine Functionalized ◽  
Nanocomposite Scaffolds ◽  
Porous Nanocomposite ◽  
L929 Cell Line

In this study, the preparation of porous nanocomposite scaffolds (HX-CNT) from a combination of a hydroxamic derivative of alginate (HX) and an amine-functionalized multiwalled carbon nanotube (CNT) at different concentrations is described. The structure of HX was investigated by FTIR, and the degree of substitution around 9% was confirmed by elemental analysis. The interaction between CNT and alginate derivative in the nanocomposite crosslinked with calcium was confirmed by FTIR, Raman spectroscopy, and SEM. The results obtained in this study showed that scaffolds based on HX-CNT composites with a 4 wt% concentration level exhibited improved physical and mechanical properties compared to plain alginate (Young’s modulus increased from 2.2 to 5.1 MPa and elastic strength from 0.13 to 0.25 MPa) and decreased the swelling ratios from ~900 to ~673. The cytotoxicity assays using the L929 cell line proved that the nanocomposite scaffolds were nontoxic, even at the highest CNT concentration.

ERDA and Structural Characterization of Oriented Multiwalled Carbon Nanotubes

2007 ◽  
Vol 111 (28) ◽  
pp. 10353-10358 ◽  
Author(s):  
A. Gohier ◽  
S. Point ◽  
M. A. Djouadi ◽  
A. Granier ◽  
T. M. Minea ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Structural Characterization ◽  
Multiwalled Carbon
Sign in / Sign up

Export Citation Format

Share Document