This article discusses the enhancement of localization in one-dimensional random potentials with long-range correlations.

The effect of hydrogen on the fracture toughness properties of Types 304L, 316L and 21-6-9 forged stainless steels was investigated. Fracture toughness samples were fabricated from forward-extruded forgings. Samples were uniformly saturated with hydrogen after exposure to hydrogen gas at 34 MPa or 69 and 623 K prior to testing. The fracture toughness properties were characterized by measuring the J-R behavior at ambient temperature in air. The results show that the hydrogen-charged steels have fracture toughness values that were about 50-60% of the values measured for the unexposed steels. The reduction in fracture toughness was accompanied by a change in fracture appearance. Both uncharged and hydrogen-charged samples failed by microvoid nucleation and coalescence, but the fracture surfaces of the hydrogen-charged steels had smaller microvoids. Type 316L stainless steel had the highest fracture toughness properties and the greatest resistance to hydrogen degradation.

Relatively large values of objective-lens defocus must normally be used to produce detectable levels of image contrast for unstained biological specimens, which are generally weak phase objects. As a result, a subsequent restoration operation must be used to correct for oscillations in the contrast transfer function (CTF) at higher resolution. Currently used methods of CTF-correction assume the ideal case in which Friedel mates in the scattered wave have contributed pairs of Fourier components that overlap with one another in the image plane. This"ideal" situation may be only poorly satisfied, or not satisfied at all, as the particle size gets smaller, the defocus value gets larger, and the resolution gets higher. We have therefore investigated whether currently used methods of CTF correction are also effective in restoring the single-sideband image information that becomes displaced (delocalized) by half (or more) the diameter of a particle of finite size. Computer simulations are used to show that restoration either by"phase flipping" or by multiplying by the CTF recovers only about half of the delocalized information. The other half of the delocalized information goes into a doubly defocused"twin" image of the type produced during optical reconstruction of an in-line hologram. Restoration with a Wiener filter …

Edible oils have emerged as an effective treatment amendment for a variety of contaminants. When applied to chlorinated volatile organic compounds (cVOCs) in the saturated zone, edible oils have been shown to enhance anaerobic bioremediation and sequester the contaminants. However, edible oils have not been applied to the vadose zone for contaminant treatment. Soybean oil was injected into the vadose zone in M-Area at the Department of Energy's (DOE) Savannah River Site (SRS) as a research study to evaluate the effectiveness of edible oils for solvent sequestration and the ability to change a vadose system from aerobic to anaerobic to initiate reductive dechlorination. The proposed use of this technique would be an enhanced attenuation/transition step after active remediation. The goals of the research were to evaluate oil emplacement methods and monitoring techniques to measure oil placement, partitioning and degradation. Gas sampling was the cornerstone for this evaluation. Analyses for cVOCs and biotransformation products were performed. Overall, the cVOC concentration/flux reduction was 75-85% in this vadose zone setting. Destruction of the cVOCs by biotic or abiotic process has not yet been verified at this site. No reductive dechlorination products have been measured. The deployment has resulted in a substantial generation of …

Article discussing work function changes induced by charged adsorbates and the origin of the polarity asymmetry.