Inorganic nanowires

Provided in one embodiment is a method of forming an inorganic nanowire, comprising: providing an elongated organic scaffold; providing a plurality of inorganic nanoparticles attached to the organic scaffold along a length of the organic scaffold; and fusing the nanoparticles attached to the organic scaffold to form an inorganic nanowire.Board of Regents, University of Texas Syste

Surface-induced layer formation in polyelectrolytes

We analyze, by means of an RPA calculation, the conditions under which a mixture of oppositely charged polyelectrolytes can micro-segregate in the neighborhood of a charged surface creating a layered structure. A number of stable layers can be formed if the surface is sufficiently strongly charged even at temperatures at which the bulk of the mixture is homogeneous.Comment: 6 pages, 3 figures, revtex, epsf, psfi

Competing Interactions among Supramolecular Structures on Surfaces

A simple model was constructed to describe the polar ordering of non-centrosymmetric supramolecular aggregates formed by self assembling triblock rodcoil polymers. The aggregates are modeled as dipoles in a lattice with an Ising-like penalty associated with reversing the orientation of nearest neighbor dipoles. The choice of the potentials is based on experimental results and structural features of the supramolecular objects. For films of finite thickness, we find a periodic structure along an arbitrary direction perpendicular to the substrate normal, where the repeat unit is composed of two equal width domains with dipole up and dipole down configuration. When a short range interaction between the surface and the dipoles is included the balance between the up and down dipole domains is broken. Our results suggest that due to surface effects, films of finite thickness have a none zero macroscopic polarization, and that the polarization per unit volume appears to be a function of film thickness.Comment: 3 pages, 3 eps figure

Biotransformation of indigo carmine to isatin sulfonic acid by lyophilized mycelia from Trametes versicolor

Indigo carmine (IC) was biotrasformed to 5-isatinsulfonic acid using intracellular and associated enzymes from Trametes versicolor lyophilized mycelia; even when extracellular enzymes were absent, in high concentration solutions of IC (4 000 mg L-1) and non-sterile condition. T. versicolor was grown in wheat strew and malt extract liquid medium and harvested during the stationary growth phase, it was lyophilized and made to react with indigo carmine. Experimental series were performed at different IC concentrations (from 100 to 4000 mg L-1). Color removal was 99.90, 98.75, 88.35, 79.47, 70.0 and 40.35% for 100, 500, 1000, 2000, 3000 and 4000 mg L-1 of IC, respectively after 120 h with exception for 100 mg L-1 of IC, which reached total color removal after 1 h. Reacted mixture byproducts were separated by column chromatography. IC biotransformation to 5-isatinsulfonic acid was confirmed by HPLC, UV-VIS, FT- IR, 1H and 13C NMR spectroscopy. Activity of laccase from lyophilized mycelia was conserved after one year at 4°C. Dehydrated biological material in colorant biodegradation is a new method which allows obtaining high discoloration efficiencies. Lyophilized mycelia could be more stable than traditionally used wet biomass or liquid culture for biodegradation of color dye.Key words: Biodegradation, indigo carmine, Trametes versicolor

Ultra Low-Power Analog Median Filters

The design and implementation of three analog median filter topologies, whose transistors operate in the deep weak-inversion region, is described. The first topology is a differential pairs array, in which drain currents are driven into two nodes in a differential fashion, while the second topology is based on a wide range OTA, which is used to maximize the dynamic range. Finally, the third topology uses three range-extended OTAs. The proposed weak-inversion filters were designed and fabricated in ON Semiconductor 0.5 micrometer technology through MOSIS. Experimental results of three-input fabricated prototypes for all three topologies are show, where power consumptions of 90nW in the first case, and 270nW in the other two cases can be noticed. A dual power supply +/-1.5 Volts were used

Synchronization of the Frenet-Serret linear system with a chaotic nonlinear system by feedback of states

A synchronization procedure of the generalized type in the sense of Rulkov et al [Phys. Rev. E 51, 980 (1995)] is used to impose a nonlinear Malasoma chaotic motion on the Frenet-Serret system of vectors in the differential geometry of space curves. This could have applications to the mesoscopic motion of biological filamentsComment: 12 pages, 7 figures, accepted at Int. J. Theor. Phy