Experimental Study of Electrophoretic Deposited Carbon Nanotubes on Microstrip Transmission Line Resonators and Filters

The electrical properties of single-walled carbon nanotube electrophoreses deposition on different types of gold-plated microstrip devices are investigated. Simple transmission lines, transmission line resonators and filters were subjected to deposition of functionalized tubes in an aqueous solution. It is found that the process lowers the resonant frequency of the resonators and filters compared to the untreated devices, at the cost of increased insertion loss and reduced resonator Q-factor

Parallel String Sample Sort

We discuss how string sorting algorithms can be parallelized on modern multi-core shared memory machines. As a synthesis of the best sequential string sorting algorithms and successful parallel sorting algorithms for atomic objects, we propose string sample sort. The algorithm makes effective use of the memory hierarchy, uses additional word level parallelism, and largely avoids branch mispredictions. Additionally, we parallelize variants of multikey quicksort and radix sort that are also useful in certain situations.Comment: 34 pages, 7 figures and 12 table

Existence of Nearest Neighbor and Variable Range Hopping in Pr2_2ZnMnO6_6

A joint investigation of X-ray diffraction (XRD) pattern and Raman spectrum authenticate the double phase monoclinic P21/n and cubic Fd-3m structures of polycrystalline Pr2ZnMnO6 (PZM). The existence of two different conduction mechanisms (Nearest neighbor hopping and Motts variable range hopping) is observed using a combined study of conductivity, dielectric relaxation and impedance spectra in PZM. This investigation point towards a transition from nearest neighbor hoping to Motts variable range hopping mechanism due to lowering activation energy around 580 K. The charge carriers hopping between the localized acceptor states at the grain boundaries (GBs), which dominants conduction mechanism below 580 K. The ac conductivity, dielectric relaxation, Nyquist plot, and electric modulus highlight the blended effect of grains (Gs) and GBs leads to the charge carrier dynamics in PZM. The dielectric relaxation and modulus formalism are analyzed on the basis of empirical Cole-Cole model. The conduction mechanism is found to be highly correlated with the relaxation mechanism and impedance spectroscopy.Comment: 15 page

Spiral-wave Dynamics Depends Sensitively on nhomogeneities in Mathematical Models of Ventricular Tissue

Every sixth death in industrialised countries occurs because of cardiac arrhythmias like ventricular tachycardia (VT) and ventricular fibrillation (VF). There is growing consensus that VT is associated with an unbroken spiral wave of electrical activation on cardiac tissue but VF with broken waves, spiral turbulence, spatiotemporal chaos and rapid, irregular activation. Thus spiral-wave activity in cardiac tissue has been studied extensively. Nevertheless many aspects of such spiral dynamics remain elusive because of the intrinsically high-dimensional nature of the cardiac-dynamical system. In particular, the role of tissue heterogeneities in the stability of cardiac spiral waves is still being investigated. Experiments with conduction blocks in cardiac tissue yield a variety of results: some suggest that blocks can eliminate VF partially or completely, leading to VT or quiescence, but others show that VF is unaffected by obstacles. We propose theoretically that this variety of results is a natural manifestation of a fractal boundary that must separate the basins of the attractors associated, respectively, with VF and VT. We substantiate this with extensive numerical studies of Panfilov and Luo-Rudy I models, where we show that the suppression of VF depends sensitively on the position, size, and nature of the inhomogeneity.Comment: 9 pages, 5 figures