(R1966) Semi Analytical Approach to Study Mathematical Model of Atmospheric Internal Waves Phenomenon

This research aims to study atmospheric internal waves which occur within the fluid rather than on the surface. The mathematical model of the shallow fluid hypothesis leads to a coupled nonlinear system of partial differential equations. In the shallow flow model, the primary assumption is that vertical size is smaller than horizontal size. This model can precisely replicate atmospheric internal waves because waves are dispersed over a vast horizontal area. A semi-analytical approach, namely modified differential transform, is applied successfully in this research. The proposed method obtains an approximate analytical solution in the form of convergent series without any linearization, perturbation, or calculation of unneeded terms, which is a significant advantage over other existing methods. To test the effectiveness and accuracy of the proposed method, obtained results are compared with Elzaki Adomain Decomposition Method, Modified Differential Transform Method, and Homotopy Analysis Method

Carbon Nanotube Solar Cells

We present proof-of-concept all-carbon solar cells. They are made of a photoactive side of predominantly semiconducting nanotubes for photoconversion and a counter electrode made of a natural mixture of carbon nanotubes or graphite, connected by a liquid electrolyte through a redox reaction. The cells do not require rare source materials such as In or Pt, nor high-grade semiconductor processing equipment, do not rely on dye for photoconversion and therefore do not bleach, and are easy to fabricate using a spray-paint technique. We observe that cells with a lower concentration of carbon nanotubes on the active semiconducting electrode perform better than cells with a higher concentration of nanotubes. This effect is contrary to the expectation that a larger number of nanotubes would lead to more photoconversion and therefore more power generation. We attribute this to the presence of metallic nanotubes that provide a short for photo-excited electrons, bypassing the load. We demonstrate optimization strategies that improve cell efficiency by orders of magnitude. Once it is possible to make semiconducting-only carbon nanotube films, that may provide the greatest efficiency improvement

Optimized CNSCs.

<p>Optimized CNSCs.</p

Parameters of CNSCs.

<p>Parameters of CNSCs.</p

Scaling analysis of CNSC performance.

<p>The CNSCs characteristics are determined by the metallic and semiconducting carbon nanotube densities, with symbols corresponding to the cells as in the legend for <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0037806#pone-0037806-g002" target="_blank">figure 2</a>. a) . b) .</p

Carbon nanotube solar cells; comparison to Dye-Sensitized Solar Cells (DSSC), construction, and energeticts.

<p>a) DSSC. b) Carbon Nanotube Solar Cell, CNSC. c) Layout of a CNSC. The top and bottom glass slides (light blue) are covered in carbon nanotube films which are electrically connected by the iodide-triiodide electrolyte (light red) that is contained by the silicone separator (white). The top film (green) is the photoactive electrode, while the bottom electrode (grey) is the counter electrode. The inset is an Atomic Force Micrograph of the height of a 2×2 m section of a carbon nanotube film. d) Band diagram of the CNSC.</p