Typical length scales in conducting disorderless networks

We take advantage of a recently established equivalence, between the intermittent dynamics of a deterministic nonlinear map and the scattering matrix properties of a disorderless double Cayley tree lattice of connectivity $K$, to obtain general electronic transport expressions and expand our knowledge of the scattering properties at the mobility edge. From this we provide a physical interpretation of the generalized localization length.Comment: 12 pages, 3 figure

Random matrix study for a three-terminal chaotic device

We perform a study based on a random-matrix theory simulation for a three-terminal device, consisting of chaotic cavities on each terminal. We analyze the voltage drop along one wire with two chaotic mesoscopic cavities, connected by a perfect conductor, or waveguide, with one open mode. This is done by means of a probe, which also consists of a chaotic cavity that measure the voltage in different configurations. Our results show significant differences with respect to the disordered case, previously considered in the literature.Comment: Proccedings of the V Leopoldo Garcia-Colin Mexican Meeting on Mathematical and Experimental Physic

Absorption and Direct Processes in Chaotic Wave Scattering

Recent results on the scattering of waves by chaotic systems with losses and direct processes are discussed. We start by showing the results without direct processes nor absorption. We then discuss systems with direct processes and lossy systems separately. Finally the discussion of systems with both direct processes and loses is given. We will see how the regimes of strong and weak absorption are modified by the presence of the direct processes.Comment: 8 pages, 4 figures, Condensed Matter Physics (IV Mexican Meeting on Mathematical and Experimental Physics), Edited by M. Martinez-Mares and J. A. Moreno-Raz

Aerobic Biodegradation of Alternative Fuel Oxygenates in Unsaturated Soil Columns

Groundwater contamination problems caused by methyl-tertiary butyl ether (MTBE) in subsurface waters have prompted the search for a gasoline oxygenate replacement. In order to avoid the problems encountered with MTBE, it is prudent to evaluate the fate and transport in the subsurface of proposed replacements, such as ethanol. In this study, ethanol transport and degradation in unsaturated soil was investigated using a series of eight soil columns. This preliminary study was to see if the soil column system components functioned properly, how similarly the eight soil columns performed, and if soil oxygen concentration affected degradation of ethanol. Tracer tests, using sodium chloride, determined the hydraulic characteristics of the soil columns. Oxygen sensors measured microbial activity in the soil columns when ethanol was added to the columns. The sensors were part of a control system that stabilized oxygen concentration at two levels (8% in four columns and 16% in four columns) to see the effect of oxygen concentration on ethanol degradation. A gas chromatograph (GC) was used to quantify column influent and effluent ethanol concentrations. The tracer tests showed an average retention time, pore volume, and mass balance error of 13.3 hr (± 1.4), 18.9 L (± 2.0), and 1.3% (± 3.8), respectively. The oxygen sensor data, which indicated a drop in oxygen concentration over time when ethanol was added, suggested that microbial activity was occurring. The microbial aerobic metabolism of ethanol caused the oxygen concentrations to drop to the set points of 8% and 16%, at which they stabilized. The GC analysis also showed ethanol degradation. Influent ethanol concentrations were ~ 1000 ppm, column effluent concentrations were at or near the method detection limit (MDL) of 1 ppm for both oxygen concentrations