Benchmark of FEM, Waveguide and FDTD Algorithms for Rigorous Mask Simulation

An extremely fast time-harmonic finite element solver developed for the transmission analysis of photonic crystals was applied to mask simulation problems. The applicability was proven by examining a set of typical problems and by a benchmarking against two established methods (FDTD and a differential method) and an analytical example. The new finite element approach was up to 100 times faster than the competing approaches for moderate target accuracies, and it was the only method which allowed to reach high target accuracies.Comment: 12 pages, 8 figures (see original publication for images with a better resolution

REPORT OF INVENTION ON THE PREPARATION OF PLUTONIUM TRIFLUORIDE

A method is described for the preparation of PuF/sub 3/ by means of a solid phase-gas reaction between Pu(IV) oxatate or Pu(III) oxalate and Freon-type compounds such as CC1/sub 2/F/sib 2/. (auth

Discrepancies in Determinations of the Ginzburg-Landau Parameter

Long-standing discrepancies within determinations of the Ginzburg-Landau parameter $\kappa$ from supercritical field measurements on superconducting microspheres are reexamined. The discrepancy in tin is shown to result from differing methods of analyses, whereas the discrepancy in indium is a consequence of significantly differing experimental results. The reanalyses however confirms the lower $\kappa$ determinations to within experimental uncertainties.Comment: submitted to Phys. Rev.

Pine growth variation associated with overburden rock type on a reclaimed surface mine in Virginia

ABSTRACT This study was designed to compare the effects of two overburden spoil types and various mixtures of the two spoils on the performance of pitch X loblolly hybrid pine (Pinus X rigitaeda). Sandstone and siltstone overburden were used to create five rock mix treatments: pure sandstone (SS), pure siltstone (SiS), a 2:1 SS/SiS mix, a 1:1 SS/SiS mix, and a 1:2 SS/SiS mix. Tree survival was not affected by rock mix, but growth was greatly affected. The greatest growth response occurred on the SS treatment and decreased as the amount of siltstone increased in the rock mix. The average stem volume of trees on the SS treatment was nearly five times greater than trees on the SiS treatment. The coarse fragment content of the SS (52%) was much lower than the SiS (72%), thus providing a greater volume of fine earth (<2 mm) for water retention and root exploitation. The pH of the SS was much lower than SiS (5.7 vs. 7.1), and available Mn was higher in the SS than in the SiS (540 vs. 160 mg kg ' foliar Mn). The results of this study demonstrate the need to consider the effects of various overburden types on tree growth when forest land is the designated post-mining land use. T^ORESTRY is a logical land use for many reclaimed r mined sites in the Appalachians, especially those that are too remote or steep to be useful for crops, hay production, or grazing. Studies have revealed that excellent tree growth is possible on reclaimed mined sites. Torbert et al. (1988) reported white pine (Pinus strobus L.) heights of up to 6.9 m for 10-yr-old white pines on reclaimed sites in Virginia. On mined sites in Illinois, Ashby et al. (1984) reported excellent growth of 30-yr-old white oak (Quercus alba L.) and yellow-poplar (Liriodendron tulipifera L.) with site indices (base age 50) of 28.6 and 29.6 m, respectively

Combining Contrast Invariant L1 Data Fidelities with Nonlinear Spectral Image Decomposition

This paper focuses on multi-scale approaches for variational methods and corresponding gradient flows. Recently, for convex regularization functionals such as total variation, new theory and algorithms for nonlinear eigenvalue problems via nonlinear spectral decompositions have been developed. Those methods open new directions for advanced image filtering. However, for an effective use in image segmentation and shape decomposition, a clear interpretation of the spectral response regarding size and intensity scales is needed but lacking in current approaches. In this context, $L^1$ data fidelities are particularly helpful due to their interesting multi-scale properties such as contrast invariance. Hence, the novelty of this work is the combination of $L^1$-based multi-scale methods with nonlinear spectral decompositions. We compare $L^1$ with $L^2$ scale-space methods in view of spectral image representation and decomposition. We show that the contrast invariant multi-scale behavior of $L^1-TV$ promotes sparsity in the spectral response providing more informative decompositions. We provide a numerical method and analyze synthetic and biomedical images at which decomposition leads to improved segmentation.Comment: 13 pages, 7 figures, conference SSVM 201

Continuous optical loading of a Bose-Einstein Condensate

The continuous pumping of atoms into a Bose-Einstein condensate via spontaneous emission from a thermal reservoir is analyzed. We consider the case of atoms with a three-level $\Lambda$ scheme, in which one of the atomic transitions has a very much shorter life-time than the other one. We found that in such scenario the photon reabsorption in dense clouds can be considered negligible. If in addition inelastic processes can be neglected, we find that optical pumping can be used to continuously load and refill Bose-Einstein condensates, i.e. provides a possible way to achieve a continuous atom laser.Comment: 12 pages, 8 figure

Periodically-dressed Bose-Einstein condensates: a superfluid with an anisotropic and variable critical velocity

Two intersecting laser beams can produce a spatially-periodic coupling between two components of an atomic gas and thereby modify the dispersion relation of the gas according to a dressed-state formalism. Properties of a Bose-Einstein condensate of such a gas are strongly affected by this modification. A Bogoliubov transformation is presented which accounts for interparticle interactions to obtain the quasiparticle excitation spectrum in such a condensate. The Landau critical velocity is found to be anisotropic and can be widely tuned by varying properties of the dressing laser beams.Comment: 5 pages, 4 figure