Generalizing Effective Spatial Bandwidth for Pole Location in MAS: The Elliptic Cylinder

The location of poles in the method of auxiliary sources for 2-D scatterers can be assisted using the effective spatial bandwidth (EBW) of the incident and scattered fields. Previously, only circular boundaries were considered. Here, EBW is extended to noncircular boundaries. Calculations presented for a cylinder with elliptical cross section verify EBW as an additional tool for pole placement for more general geometries

The left-right dimension in Latin America

We present voters' self-placement and 68 political party locations on the left-right dimension in 17 Latin American countries. Innovative calculations are based on data from Latinobarometer annual surveys from 1995 to 2002. Our preliminary analysis of the results suggests that most Latin American voters are relatively highly ideological and rather consistently located on the left-right dimension, but they have very high levels of political alienation regarding the party system. Both voters' self-placement and the corresponding party locations are presently highly polarized between the center and the right, with a significant weakness of leftist or broadly appealing 'populist' positions.Political ideology, left-right dimension, political parties, electoral competition

Density functional investigations of defect induced mid-gap states in graphane

We have carried out ab initio electronic structure calculations on graphane (hydrogenated graphene) with single and double vacancy defects. Our analysis of the density of states reveal that such vacancies induce the mid gap states and modify the band gap. The induced states are due to the unpaired electrons on carbon atoms. Interestingly the placement and the number of such states is found to be sensitive to the distance between the vacancies. Furthermore we also found that in most of the cases the vacancies induce a local magnetic moment.Comment: 15 page

Determination of wind turbine far wake using actuator disk

The growth in size of wind turbines over the last years is significant. The rotor diameter becomes somehow comparable to atmospheric boundary layer at the land surface. In this case the assumption of uniform velocity of upcoming wind cannot be valid. The aim of this paper is to create a simplified model of wind turbine rotor which can represent the aerodynamic inter-action of atmospheric boundary layer with a horizontal axis wind turbine. Such model will be also useful for the study of optimal placement of wind turbines in a wind farm when a large number of calculations is needed and when the time required for full CFD calculations be-comes prohibitive. In this study we adopt actuator disk model which takes in account with sufficient precision the influence of blade geometry on wind turbine aerodynamic performance. The proposed actuator disk model is tested in the case of horizontal axis wind turbine using wall-modelled large eddy simulation. The obtained results of aerodynamic performance and wake show the rapidity of calculation and the reliability of proposed approach

Validation and application of a computational model for wrist and hand movements using surface markers

A kinematic model is presented based on surface marker placement generating wrist, metacarpal arch, fingers and thumb movements. Standard calculations are used throughout the model and then applied to the specified marker placement. A static trial involving eight unimpaired participants was carried out to assess inter-rater reliability. The standard deviations across the data were comparable to manual goniometers. In addition, a test retest trial of ten unimpaired participants is also reported to illustrate the variability of movement at the wrist joint, metacarpal arch, and index finger as an example of model output when repeating the same task many times. Light and heavyweight versions of the tasks are assessed and characteristics of individual movement strategies presented. The participant trial showed moderate correlation in radial/ulnar deviation of the wrist ( = 0 65), and strong correlation in both metacarpal arch joints ( = 075 and = 085), the MCP ( = 079), and PIP ( = 087) joints of the index finger. The results indicate that individuals use repeated strategies of movement when lifting light and heavyweight versions of the same object, but showed no obvious repeated pattern of movement across the population

A Free Energy Model of Boron Carbide

The assessed phase diagram of the boron-carbon system contains a single non-stoichiometric boron-carbide phase of rhombohedral symmetry with a broad, thermodynamically improbable, low temperature composition range. We combine first principles total energy calculations with phenomenological thermodynamic modeling to propose a revised low temperature phase diagram that contains two boron-carbide phases of differing symmetries and compositions. One structure has composition B4C and consists of B11C icosahedra and C-B-C chains, with the placement of carbon on the icosahedron breaking rhombohedral symmetry. This phase is destabilized above 600K by the configurational entropy of alternate carbon substitutions. The other structure, of ideal composition B13C2, has a broad composition range at high temperature, with rhombohedral symmetry throughout, as observed experimentally.Comment: 15 pages, 3 figures, submitted to J. Stat. Phys. August 9th, 201

Influence of Mortar Rheology on Aggregate Settlement

The influence of the rheology of fresh concrete on the settlement of aggregate is examined. Fresh concrete exhibits a yield stress that, under certain conditions, prevents the settlement of coarse aggregate, although its density is larger than that of the suspending mortar. Calculations, based on estimates of the yield stress obtained from slump tests, predict that aggregate normally used in concrete should not sink. To test this prediction, the settlement of a stone in fresh mortar is monitored. The stone does not sink in the undisturbed mortar (which has a high yield stress), but sinks when the mortar is vibrated, presumably due to a large reduction in its yield stress. This implies that during placement of concrete, the aggregate settles only while the concrete is being vibrated. A unique experimental method for measuring aggregate settlement is also introduced and demonstrated

Structural studies of phosphorus induced dimers on Si(001)

Renewed focus on the P-Si system due to its potential application in quantum computing and self-directed growth of molecular wires, has led us to study structural changes induced by P upon placement on Si(001)-$p(2\times 1)$. Using first-principles density functional theory (DFT) based pseudopotential method, we have performed calculations for P-Si(001) system, starting from an isolated P atom on the surface, and systematically increasing the coverage up to a full monolayer. An isolated P atom can favorably be placed on an {\bf M} site between two atoms of adjacent Si dimers belonging to the same Si dimer row. But being incorporated in the surface is even more energetically beneficial due to the participation of the {\bf M} site as a receptor for the ejected Si. Our calculations show that up to 1/8 monolayer coverage, hetero-dimer structure resulting from replacement of surface Si atoms with P is energetically favorable. Recently observed zig-zag features in STM are found to be consistent with this replacement process. As coverage increases, the hetero-dimers give way to P-P ortho-dimers on the Si dimer rows. This behavior is similar to that of Si-Si d-dimers but are to be contrasted with the Al-Al dimers, which are found between adjacent Si dimers rows and in a para-dimer arrangement. Unlike Al-Si system P-Si does not show any para to ortho transition. For both systems, the surface reconstruction is lifted at about one monolayer coverage. These calculations help us in understanding the experimental data obtained using scanning tunneling microscope.Comment: To appear in PR