This paper presents a robust control scheme for a distributed solar collector (DSC) field. As DSC are systems subjected to strong disturbances (mainly in solar radiation and inlet oil temperature), a series feedforward is used as a part of the plant, so that the system to be controlled has one input (fluid flow) and one output (outlet temperature) as the disturbances are partially compensated b...

Suspensions of nanoparticles (i.e., particles with diameters < 100 nm) in liquids, termed nanofluids, show remarkable thermal and optical property changes from the base liquid at low particle loadings. Recent studies also indicate that selected nanofluids may improve the efficiency of direct absorption solar thermal collectors. To determine the effectiveness of nanofluids in solar applications,...

Introduction: Nearly four decades of experimental studies have failed to agree on an isotopic composition for solar wind (SW) nitrogen implanted in lunar regolith grains. Estimates of ! 15 N range from > +200 ‰ [1] to < -250 ‰ [2]. Its actual value is crucial, not only for untangling component mixtures in the lunar system but also in elucidating the sources and isotopic evolution of N in other ...

The optical characterization is reported of a new fluid consisting of single wall carbon nanohorns and ethylene glycol for solar energy applications. Carbon nanohorns play a significant role in enhancing sunlight absorption with respect to the pure base fluid. The obtained results are compared with those obtained for fluids suspending more conventional carbon forms, i.e. carbon-black particles....

This paper presents an optimization algorithm for designing linear concentrating solar collectors using stochastic programming. A Monte Carlo technique is used to quantify the performance of the collector design in terms of an objective function, which is then minimized using a modified Kiefer-Wolfowitz algorithm that uses sample size and step size controls. This process is more efficient than ...

Three-dimensional (3D) structures such as nanowires, nanotubes, and nanorods have the potential to increase surface area, reduce light reflection, and shorten charge carrier transport distances. The assembly of such structures thus holds great promise for enhancing photoelectrochemical solar cell efficiency. In this study, genetically modified Tobacco mosaic virus (TMV1cys) was used to form sel...

Planar micro-optic concentrators are passive optical structures which combine a lens array with faceted microstructures to couple sunlight into a planar slab waveguide. Guided rays propagate within the slab to edge-mounted photovoltaic cells. This paper provides analysis and preliminary experiments describing modifications and additions to the geometry which increase concentration ratios along ...

T R I B O L O G Y & L U B R I C A T I O N T E C H N O L O G Y W W W . S T L E . O R G evelopment of alternative energy sources has been a daunting task from both the technology and economic standpoints. a case in point is capturing solar energy for use in generating electricity. in a previous tLt article, a heat transfer fluid is found to be an integral component in a parabolic mirror used to c...