Two-Dimensional Diffusion in the Presence of Topological Disorder

How topological defects affect the dynamics of particles hopping between lattice sites of a distorted, two-dimensional crystal is addressed. Perturbation theory and numerical simulations show that weak, short-ranged topological disorder leads to a finite reduction of the diffusion coefficient. Renormalization group theory and numerical simulations suggest that longer-ranged disorder, such as that from randomly placed dislocations or random disclinations with no net disclinicity, leads to subdiffusion at long times.Comment: 10 pages, 6 figure

Inaccuracy of Density Functional Theory Calculations for Dihydrogen Binding Energetics onto Ca Cation Centers

We investigate the mechanism of dihydrogen adsorption onto Ca cation centers, which has been the significant focus of recent research for hydrogen storage. We particularly concentrate on reliability of commonly used density-functional theories, in comparison with correlated wave function theories. It is shown that, irrespective of the chosen exchange-correlation potentials, density-functional theories result in unphysical binding of H2 molecules onto Ca1+ system. This suggests that several previous publications could contain a serious overestimation of storage capacity at least in part of their results.open262

Dissociation of ssDNA - Single-Walled Carbon Nanotube Hybrids by Watson-Crick Base Pairing

The unwrapping event of ssDNA from the SWNT during the Watson-Crick base paring is investigated through electrical and optical methods, and binding energy calculations. While the ssDNA-metallic SWNT hybrid shows the p-type semiconducting property, the hybridization product recovered metallic properties. The gel electrophoresis directly verifies the result of wrapping and unwrapping events which was also reflected to the Raman shifts. Our molecular dynamics simulations and binding energy calculations provide atomistic description for the pathway to this phenomenon. This nano-physical phenomenon will open up a new approach for nano-bio sensing of specific sequences with the advantages of efficient particle-based recognition, no labeling, and direct electrical detection which can be easily realized into a microfluidic chip format.Comment: 4 pages, 4 figure

Fine structure of alpha decay in odd nuclei

Using an alpha decay level scheme, an explanation for the fine structure in odd nuclei is evidenced by taking into account the radial and rotational couplings between the unpaired nucleon and the core of the decaying system. It is stated that the experimental behavior of the alpha decay fine structure phenomenon is directed by the dynamical characteristics of the system.Comment: 8 pages, 3 figures, REVTex, submitted to Physical Review

On Less Conservative Stability Criteria for Neural Networks with Time-Varying Delays Utilizing Wirtinger-Based Integral Inequality

This paper investigates the problem of stability analysis for neural networks with time-varying delays. By utilizing the Wirtinger-based integral inequality and constructing a suitable augmented Lyapunov-Krasovskii functional, two less conservative delay-dependent criteria to guarantee the asymptotic stability of the concerned networks are derived in terms of linear matrix inequalities (LMIs). Three numerical examples are included to explain the superiority of the proposed methods by comparing maximum delay bounds with the recent results published in other literature

Estimation the Performance of Solar Fiber Optic Lighting System after Repairing the Glass Fiber Cables in a South Korean Residential Building

The solar fiber optic lighting system consists of the solar ray concentrating apparatus, the tracking control, lighting transmission and emission parts. This system was installed on a 20-storey apartment building in South Korea. Many residents had concerns about its long-term maintenance. The most common maintenance difficulties are sun tracking problems and damaged glass fiber cables. Sometimes fiber optic lighting systems should not be repaired with splices. Splicing glass fiber cables often results in decreased system efficiency and further cable damage. In this study, the cost of replacing the cables was prohibitive; hence, the drop in efficiency of the damaged cables was answered by repairing through splicing. These damaged cables were repaired by specially process of cutting and polishing. Results showed that the luminous intensity ratio improved by 0.391%, though this was still lower than the recommended guideline of 0.725%. Accordingly, on average 55% of luminous intensity was increased

Performance Evaluation of Hot Water Efficiency Plumbing System Using Thermal Valve

In Korea two popular water distribution systems—the branch type and the separate type systems—have serious drawbacks. The branch type suffers from temperature instability while the separate type suffers from excessive piping. Neither of them re-circulates water. The system proposed in this paper utilizes a water-conserving piping system with a thermostat valve. This paper compares the proposed system with that of the separate type. Our findings show that the proposed system wastes less water. After re-circulating for 78-87 seconds, water is available at set point temperature (40°C). Also, when multiple water taps are in use, the average temperature deviation is less than 0.6°C. Moreover, the proposed system has 50% less flow rate than the separate type system.Hyundai Engineering and Consulting Co