9,700 research outputs found
Quantum Properties of a Which-Way Detector
We explore quantum properties of a which-way detector using three versions of
an idealized two slit arrangements. Firstly we derive complementarity relations
for the detector; secondly we show how the "experiment" may be altered in such
a way that using single position measurement on the screen we can obtain
quantum erasure. Finally we show how to construct a superposition of "wave" and
"particle" components
Compactly Supported Wavelets Derived From Legendre Polynomials: Spherical Harmonic Wavelets
A new family of wavelets is introduced, which is associated with Legendre
polynomials. These wavelets, termed spherical harmonic or Legendre wavelets,
possess compact support. The method for the wavelet construction is derived
from the association of ordinary second order differential equations with
multiresolution filters. The low-pass filter associated with Legendre
multiresolution analysis is a linear phase finite impulse response filter
(FIR).Comment: 6 pages, 6 figures, 1 table In: Computational Methods in Circuits and
Systems Applications, WSEAS press, pp.211-215, 2003. ISBN: 960-8052-88-
ANALYTICAL SOLUTION OF A 2D TRANSIENT HEAT CONDUCTION PROBLEM USING GREEN´S FUNCTIONS
Through the present work the authors determined the analytical solution of a transient two-dimensional heat conduction problem using Green’s Functions (GF). This method is very useful for solving cases where heat conduction is transient and whose boundary conditions vary with time. Boundary conditions of the problem in question, with rectangular geometry, are of the prescribed temperature type - prescribed flow in the direction x and prescribed flow - prescribed flow in the direction y, implying in the corresponding GF given by GX21Y22. The initial temperature of the space domain is assumed to be different from the prescribed temperature occurring at one of the boundaries along x. The temperature field solution of the two-dimensional problem was determined. The intrinsic verification of this solution was made by comparing the solution of a 1D problem. This was to consider the incident heat fluxes at y = 0 and y = 2b tending to zero, thus making the problem one-dimensional, with corresponding GF given by GX21. When comparing the results obtained in both cases, for a time of t = 1 s, it was seen that the temperature field of both was very similar, which validates the solution obtained for the 2D problem
Gauging N=2 Supersymmetric Non-Linear -Models in the Atiyah-Ward Space-Time
We build up a class of N=2 supersymmetric non-linear -models in an
N=1 superspace based on the Atiyah-Ward space-time of (2+2)-signature metric.
We also discuss the gauging of isometries of the associated hyper-K\"ahlerian
target spaces and present the resulting gauge-covariant supersymmetric action
functional.Comment: 12 pages, latex, no figure
Nanominerals assemblages and hazardous elements assessment in phosphogypsum from an abandoned phosphate fertilizer industry
The present work investigates hazardous elements and nanomineralogical assemblages of phosphogypsum waste from an abandoned phosphate fertilizer industry located in Santa Catarina state (Brazil). Correlations between the chemical composition, nanominerals, and ultrafine particles are discussed. Multifaceted physical-geochemical study provided a careful understanding of the nanomineralogical assemblage of the phosphogypsum waste. The electron beam investigation revealed the presence of many hazardous elements in the ultrafine particles. Cr, Pb, Mn, Se, Sr, and Zr, among others, were found in individual ultrafine particles and nanominerals in all studied samples. Besides that, rare earth elements were found in different concentration ranges, being Ce, La, and Nd, the rare earth elements, found in the higher concentrations, above 900 mg kg−1. The data supplied by this article are important to characterize the phosphogypsum waste, assessing the potential hazard to the environment and human health, and also, provides information to enable the designing of alternatives to manage this waste
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