Self-assembled metallic nanoparticle template --- a new approach of surface nanostructuring at nanometer scale

In the present work, the formation of silver and copper nanostructures on highly oriented pyrolytic graphite (HOPG) modified with self-assembled gold nanoparticles (Au NPs) is demonstrated. Surface patterning with nanometer resolution was achieved. Different methods such as field emission scanning electron microscopy (FEGSEM), energy dispersive spectrometry (EDS) and X-ray photoelectron spectroscopy (XPS) were used to illustrate a selective deposition of silver and copper on Au NPs. The mechanism of silver and copper ions reduction on Au NP with $n$-dodecanethiol coating is discussed.Comment: 6 pages, 3 figure

Financing schemes for residential, grid-connected PV solar systems in BCS, Mexico

This article presents two proposals to spur the extensive adoption of grid-connected, residential, solar photovoltaic systems in the Mexican state of Baja California Sur. To this aim, electricity generation costs and subsidies were estimated first, together with time-of-generation avoided costs that could result from the implementation of such solar systems. An overview of financing mechanisms for solar and other renewable energies around the world is also presented followed by current mechanisms available in Mexico. The first proposal is centered around the operation of a solar energy service company that would receive the avoided cost of generation as compensation in return for sourcing, installing, and maintaining solar PV systems on residential users’ roofs. This would free up the residential user from any future electricity payments. The second proposal consists in the implementation of a feed-in tariff (FiT), currently unavailable in Mexico for residential users. The FiT could be funded from the avoided generation cost in conventional plants plus the corresponding savings from self-generation of electricity. Alternatively, the option of funding the FiT from small increases in electricity prices to all customers was also explored. Present value analyses suggest that both proposals are worthwhile pursuing in Baja California Sur

Noncommutative Multi-Instantons on R^{2n} x S^2

Generalizing self-duality on R^2 x S^2 to higher dimensions, we consider the Donaldson-Uhlenbeck-Yau equations on R^{2n} x S^2 and their noncommutative deformation for the gauge group U(2). Imposing SO(3) invariance (up to gauge transformations) reduces these equations to vortex-type equations for an abelian gauge field and a complex scalar on R^{2n}_\theta. For a special S^2-radius R depending on the noncommutativity \theta we find explicit solutions in terms of shift operators. These vortex-like configurations on R^{2n}_\theta determine SO(3)-invariant multi-instantons on R^{2n}_\theta x S^2_R for R=R(\theta). The latter may be interpreted as sub-branes of codimension 2n inside a coincident pair of noncommutative Dp-branes with an S^2 factor of suitable size.Comment: 1+8 pages, v2: reference added, version published in PL