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Negative correlation between frequency-magnitude power-law exponent and Hurst coefficient in the Long-Range Connective Sandpile model for earthquakes and for real seismicity1
by Ya-Ting Lee, Luciano Telesca and Chien-chih Chen
The Long-Range Connective Sandpile (LRCS) model was applied to the Italian seismicity. The Hurst exponent and the power-law slope of the frequency-size distributions for the avalanches in the LRCS model and for earthquakes in Italy are investigated. This study shows the transition of the correlation coefficient between b and H values with different calculation window length. The result shows similar behaviors in the LRCS model and the Italy catalogue. The negative correlation between b and H values can be clearly seen when an appropriate window length is employed for various time series. We suggest that the negative relationship is caused by the increasing correlation length as the system accumulates enough energy. Also the calculation window length is an important index to display the intensity of the negative correlation between these two exponents. The appropriate window length can be related to the period time for the avalanches with various sandpile and seismicity time series.
On the transition between complementary medium and zero-refractive-index medium2
by Fan Wang and C. T. Chan
It is known that “complementary media” which are constructed as slabs that optically cancel each other have optical properties that are different from materials with a zero refractive index. However, a zero-refractive-index material can be viewed as a special case of complementary media in which the constitutive parameters go to zero. This apparent inconsistency is resolved as we find that the optical property of a system can change from complementary-like to a zero-index–like as the system parameters change when absorption is considered properly and there is an intermediate regime in which the complementary system absorbs half of the incident light. The physical reason underlying this anomalous absorption is explained.
Electrospray cone-jet breakup and droplet production for electrolyte solutions3
by Yunshan Wang, Ming K. Tan, David B. Go and Hsueh-Chia Chang
The production of charge droplets via the electrospray of an electrolyte is experimentally and theoretically found to be a Coulombic fission phenomenon that occurs when induced space charge at the microjet interface reaches a critical density as the charge separation approaches the Bjerrum length. The field surrounding the cone is dominated by the Taylor harmonic, which is responsible for inducing space charge within an interfacial Debye layer, such that the jet breakup length and plume angle are strong functions of both the ionic strength and interfacial surface tension.
Helices at interfaces4
by Gi-Moon Nam, Nam-Kyung Lee, Hervé Mohrbach, Albert Johner and Igor M. Kulic.
Helically coiled filaments are a frequent motif in nature. In situations commonly encountered in experiments coiled helices are squeezed flat onto two-dimensional surfaces. Under such 2-d confinement helices form “squeelices”—peculiar squeezed conformations often resembling looped waves, spirals or circles. Using theory and Monte Carlo simulations we investigate the mechanics and the unusual statistical mechanics of confined helices and show that their fluctuations can be understood in terms of moving and interacting discrete particle-like entities —the “twist kinks”. We show that confined filaments can thermally switch between discrete topological twist quantized states, with some of the states exhibiting dramatically enhanced cyclisation probability while others displaying surprising hyperflexibility.
- Ya-Ting Lee, Luciano Telesca and Chien-chih Chen. 2012. Negative correlation between frequency-magnitude power-law exponent and Hurst coefficient in the Long-Range Connective Sandpile model for earthquakes and for real seismicity. EPL, 99, 29001. DOI: 10.1209/0295-5075/99/29001 [↩]
- Fan Wang and C. T. Chan. 2012. On the transition between complementary medium and zero-refractive-index medium. EPL, 99, 67002. DOI: 10.1209/0295-5075/99/67002 [↩]
- Yunshan Wang, Ming K. Tan, David B. Go and Hsueh-Chia Chang. 2012. Electrospray cone-jet breakup and droplet production for electrolyte solutions. EPL, 99, 64003. DOI: 10.1209/0295-5075/99/64003 [↩]
- Gi-Moon Nam, Nam-Kyung Lee, Hervé Mohrbach, Albert Johner and Igor M. Kulic. 2012. Helices at interfaces. EPL, 100, 28001. DOI: 10.1209/0295-5075/100/28001 [↩]
