A Method To Remove Fringes From Images Using Wavelets

We have developed a new method that uses wavelet analysis to remove interference fringe patterns from images. This method is particularly useful for flat fields in the common case where fringes vary between the calibration and object data. We analyze the efficacy of this method by creating fake flats with fictitious fringes and removing the fringes. We find that the method removes 90% of the fringe pattern if its amplitude is equal to the random noise level and 60% if the fringe amplitude is $\approx 1/10$ of the noise level. We also present examples using real flat field frames. A routine written in the Interactive Data Language (IDL) that implements this algorithm is available from the authors and as an attachment to this paper.Comment: 7 pages, 14 figures. Accepted to the Astrophysical Journal. (The quality of the figures in this preprint has been downgraded in order to fulfill arXiv requirements. Check journal for the high-quality figures

Addition of a gamma ray spectrometer to the alpha scattering experiment as designed for the Surveyor mission

Gamma ray spectroscopy and alpha scattering techniques for compositional analysis of lunar and planetary surface

A hydrochemical assessment of groundwater recharge and flow in the Broome Sandstone Aquifer, La Grange area, Western Australia

The Department of Agriculture and Food Western Australia has undertaken a four-year Royalties for Regions funded project in the La Grange Groundwater Area south of Broome. The purpose of the project was to provide improved knowledge and confidence about soil suitability and water availability for potential expansion of irrigated agriculture in the region. A range of complementary techniques have been used to assess the groundwater resources in the Broome Sandstone aquifer, including contemporary approaches such as drilling and aquifer pumping tests, and state-of-the-art approaches such as airborne geophysical surveys and hydrochemistry investigations. This report presents a synthesis of all hydrochemistry data collected from about 200 existing and recently drilled bores over three campaigns from 2013 to 2015. Major ion chemistry data, stable hydrogen and oxygen isotopes of the water molecule, chlorofluorocarbons and radiocarbon have all been used to address key knowledge gaps in the context of future irrigation development and water allocation planning. Most groundwater in the Broome Sandstone aquifer is exceptionally good quality with salinity less than 500 mg/L as total dissolved salts. Major ion compositions are consistent with a source of solutes from aerosols in rainfall of marine origin, followed by minimal water-rock interaction including weathering of soil carbonates. Stable hydrogen and oxygen isotope compositions of groundwater samples indicate that recharge to the aquifer only occurs after intense monsoonal rainfall events in the wet season. Three different environmental tracer based methods for estimating recharge rates have produced remarkably consistent results, despite differences in the spatial and temporal scales over which they apply. There are no apparent spatial trends in recharge rate, which indicates that recharge is driven by large episodic events associated with tropical cyclones rather than mean annual rainfall. Residence times of groundwater flow in the Broome Sandstone range from ‘modern’ for shallow bores to more than 20 000 years for deep bores in down-gradient parts of the aquifer. These residence times correspond to flow path lengths ranging from only a few kilometres for groundwater in the shallowest bores, to more than 150 km for groundwater in the deep bores near the coast

Calorons and BPS monopoles with non-trivial holonomy in the confinement phase of SU(2) gluodynamics

With the help of the cooling method applied to SU(2) lattice gauge theory at non-zero $T \le T_c$ we present numerical evidence for the existence of superpositions of Kraan-van Baal caloron (or BPS monopole pair) solutions with non-trivial holonomy, which might constitute an important contribution to the semi-classical approximation of the partition function.Comment: 3 pages, 6 figures, contribution to Lattice2002(topology

Lattice QCD at finite temperature: Evidence for calorons from the eigenvectors of the Dirac operator

We analyze the eigenvalues and eigenvectors of the staggered Dirac operator in quenched lattice QCD in the vicinity of the deconfinement phase transition using the L\"uscher-Weisz gauge action. The spectral and localization properties of the low-lying eigenmodes show characteristic differences between the Z_3 sectors above the critical temperature T_c. These findings can be interpreted in terms of calorons.Comment: Lattice2001(hightemp), 3 pages, 2 figure

Intrinsic dissipation in high-frequency micromechanical resonators

We report measurements of intrinsic dissipation in micron-sized suspended resonators machined from single crystals of galium arsenide and silicon. In these experiments on high-frequency micromechanical resonators, designed to understand intrinsic mechanisms of dissipation, we explore dependence of dissipation on temperature, magnetic field, frequency, and size. In contrast to most of the previous measurements of acoustic attenuation in crystalline and amorphous structures in this frequency range, ours is a resonant measurement; dissipation is measured at the natural frequencies of structural resonance, or modes of the structure associated with flexural and torsional motion. In all our samples we find a weakly temperature dependent dissipation at low temperatures. We compare and contrast our data to various probable mechanisms, including thermoelasticity, clamping, anharmonic mode-coupling, surface anisotropy and defect motion, both in bulk and on surface. The observed parametric dependencies indicate that the internal defect motion is the dominant mechanism of intrinsic dissipation in our samples