Nanofluids—a simple product of the emerging world of nanotechnology—are suspensions of nanoparticles (nominally 1–100 nm in size) in conventional base fluids such as water, oils, or glycols. Nanofluids have seen enormous growth in popularity since they were proposed by Choi in 1995. In the year 2011 alone, there were nearly 700 research articles where the term nanofluid was used in the title, showing rapid growth from 2006 (175) and 2001 (10). The first decade of nanofluid research was primarily focused on measuring and modeling fundamental thermophysical properties of nanofluids (thermal conductivity, density, viscosity, heat transfer coefficient). Recent research, however, explores the performance of nanofluids in a wide variety of other applications. Analyzing the available body of research to date, this article presents recent trends and future possibilities for nanofluids research and suggests which applications will see the most significant improvement from employing nanofluids.

Experimental studies on thermogalvanic cells (or thermo-electrochemical cells or simply thermocells) have shown promising results in the past two decades since being introduced in 1825. Recent literature on this topic ranging from aqueous redox couple cells to nonaqueous and molten salt thermogalvanic cells is reviewed and compared. Some limited new experimental data on power generation for the underdeveloped Cu-CuSO₄ system are also reported. The Seebeck coefficient values of these experiments fit with a characteristic model extracted from a 1959 paper by deBethune et al. (Journal of the Electrochemical Society, Vol. 106, 1959). The power generation results are compared with the few previously reported values of the Cu-CuSO₄ system by Holeschovsky (Analysis of Flooded Flow Fuel Cells and Thermogalvanic Generators, 1994) and Tester et al. (Evaluation of Thermogalvanic Cells for the Conversion of Heat to Electricity, 1992), including those published by Kuzminskii et al. (Journal of Power Sources, Vol. 52, 1994) and Quickenden and Mua (Journal of the Electrochemical Society, Vol. 142, 1995). Condensing the recently published literature, this article presents recent trends and identifies future possibilities or directions for realizing this attractive concept, which has been around for a long time.

For many decades, integration of concentrated solar power (CSP) and desalination relied solely on the use of conventional steam Rankine cycles with thermally based desalination technologies. However, CSP research focus is shifting toward the use of supercritical CO2 Brayton cycles due to the significant improvement in thermal efficiencies. Here, we present a techno-economic study that compares the generated power and freshwater produced from a CSP system operated with a Rankine and Brayton cycle. Such a study facilitates co-analysis of the costs of producing both electricity and water among the other trade-off assessments. To minimize the levelized cost of water (LCOW), a desalination facility utilizing multi-effect distillation with thermal vapor compression (MED/TVC) instead of multistage flash distillation (MSF) is most suitable. The techno-economic analysis reveals that in areas where water production is crucial to be optimized, although levelized cost of electricity (LCOE) values are lowest for wet-cooled recompression closed Brayton cycle (RCBR) with MSF (12.1 cents/kWhe) and MED/TVC (12.4 cents/kWhe), there is only a 0.35 cents/kWhe increase for dry-cooled RCBR with MED/TVC to a cost of 12.8 cents/kWhe. This suggests that the best candidate for optimizing water production while minimizing both LCOW and LCOE is dry-cooled RCBR with MED/TVC desalination.