A plasma light source for the VUV spectral region

The 5-50-eV spectral range appears to be absent from the planned third generation synchrotron radiation sources (SRS) and the science requiring this radiation can be jeopardized once the second generation SRS light sources are switched off worldwide. Molecular photochemistry, photobiology, atomic physics, solid-state physics are but a few sciences requiring powerful VUV sources. We demonstrate that a compact, laser heated plasma light source can generate efficiently radiation in this spectral region, and that this radiation can be coupled very efficiently from the plasma to the exposure cell, by three simple VUV beam-lines, each providing a different spectral bandwidth     

Atomic‐Level Sculpting of Crystalline Oxides: Toward Bulk Nanofabrication with Single Atomic Plane Precision

The atomic‐level sculpting of 3D crystalline oxide nanostructures from metastable amorphous films in a scanning transmission electron microscope (STEM) is demonstrated. Strontium titanate nanostructures grow epitaxially from the crystalline substrate following the beam path. This method can be used for fabricating crystalline structures as small as 1–2 nm and the process can be observed in situ with atomic resolution. The fabrication of arbitrary shape structures via control of the position and scan speed of the electron beam is further demonstrated. Combined with broad availability of the atomic resolved electron microscopy platforms, these observations suggest the feasibility of large scale implementation of bulk atomic‐level fabrication as a new enabling tool of nanoscience and technology, providing a bottom‐up, atomic‐level complement to 3D printing.     

Alkaline Injection of Concentrated Sodium Hydroxide Solution into an Acidic Surface Mine Spoil Aquifer

A series of NaOH solution injection experiments were performed as trials for in situ remediation of an acid-producing surface-mine spoil. Both 20 and 50% (w/w) concentrated NaOH solutions were employed. While the spoil immediately down-gradient of the injection wells was neutralized, only about 23% of the introduced Na was recovered at the spring discharge in 3 years of post-injection monitoring. This rate of transport was far slower than the estimated advection rates in the aquifer, indicating that substantial retardation of both Na and the associated alkalinity occurred. This retardation is ascribed to: precipitation of alkaline-earth carbonate hydroxide minerals, as well as metal hydroxide precipitates, consuming injected alkalinity; and reduction of hydraulic conductivity in the peralkaline (pH > 13) “plume” region due to plugging by reaction products. It is likely that Na and alkalinity will continue to leak from this plume region for many years, but at too slow a rate to neutralize AMD at current concentrations. Future injection efforts of this type may be feasible but should use lower concentrations and should be focused further down-gradient, in closer proximity to the springs, where ground water velocities are higher.     

A randomized trial of a representational intervention to decrease cancer pain (RIDCancerPain).

Objective: Based on theories regarding cognitive representations of illness and processes of conceptual change, a representational intervention to decrease cancer pain (RIDcancerPain) was developed and its efficacy tested. Design: A two-group RCT (RIDcancerPain versus control) with outcome and mediating variables assessed at baseline (T1) and 1 and 2 months later (T2 and T3). Subjects were 176 adults with pain related to metastatic cancer. Main Outcome Measures: Outcome variables were two pain severity measures (BPI and TPQM), pain interference with life, and overall quality of life. Mediating variables were attitudinal barriers to pain management and coping (medication use). Results: One hundred and fifty subjects completed the study. Subjects in RIDcancerPain (T1-T2 and T1-T3) showed greater decreases in Barrier scores than those in control. Subjects in RIDcancerPain (T1-T3) showed greater decreases in pain severity than those in control. Change in Barriers scores mediated the effect of RIDcancerPain on pain severity. Conclusion: RIDcancerPain was efficacious with respect to some outcomes. Further work is needed to strengthen it. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Executing effective road safety advertising: are big production budgets necessary?

Twelve (12) road safety television commercials (TVCs) ranging in production costs from $A15,000 to $A250,000 (current prices) were evaluated using standard advertising pre-test procedures. The twelve ads covered four road safety behaviours (speeding; drink driving; fatigue; and inattention), and included a variety of executional types within and across behaviours. One ad in each of the four behaviours was an expensive TAC and ($A200,000 or more). The testing procedure assessed respondents' self-reported impact of the ad on their future intentions to comply with the road safety behavior advocated in the ad. Just under 1000 appropriately screened motor vehicle drivers license holders were recruited via street intercept methods and randomly allocated to one of the twelve and exposure conditions. The results showed that while the two best performing ads were highly dramatic TAC ads showing graphic crash scenes, these were also the most expensive ads to produce, and, being 60 and 90 s, the most expensive to air. In several cases, 30 s low cost talking heads testimonials performed equally as well as their far more expensive counterparts. We conclude that big production budgets may not be necessary to create effective road safety advertising.     

Ozone differential absorption lidar algorithm intercomparison

An intercomparison of ozone differential absorption lidar algorithms was performed in 1996 within the framework of the Network for the Detection of Stratospheric Changes (NDSC) lidar working group. The objective of this research was mainly to test the differentiating techniques used by the various lidar teams involved in the NDSC for the calculation of the ozone number density from the lidar signals. The exercise consisted of processing synthetic lidar signals computed from simple Rayleigh scattering and three initial ozone profiles. Two of these profiles contained perturbations in the low and the high stratosphere to test the vertical resolution of the various algorithms. For the unperturbed profiles the results of the simulations show the correct behavior of the lidar processing methods in the low and the middle stratosphere with biases of less than 1% with respect to the initial profile to as high as 30 km in most cases. In the upper stratosphere, significant biases reaching 10% at 45 km for most of the algorithms are obtained. This bias is due to the decrease in the signal-to-noise ratio with altitude, which makes it necessary to increase the number of points of the derivative low-pass filter used for data processing. As a consequence the response of the various retrieval algorithms to perturbations in the ozone profile is much better in the lower stratosphere than in the higher range. These results show the necessity of limiting the vertical smoothing in the ozone lidar retrieval algorithm and questions the ability of current lidar systems to detect long-term ozone trends above 40 km. Otherwise the simulations show in general a correct estimation of the ozone profile random error and, as shown by the tests involving the perturbed ozone profiles, some inconsistency in the estimation of the vertical resolution among the lidar teams involved in this experiment.     

Measurement of static and vibration-induced phase noise in UHF thin-film resonator (TFR) filters

Measurements of the static phase noise and vibration sensitivity of thin-film resonator (TFR) filters operating at 640 and 2110 MHz have been made. They show that the short-term frequency instability of the filters is small compared with that induced in the oscillator signal by the sustaining stage amplifier PM (phase modulation) noise. In-oscillator measurement of filter performance under vibration indicates that fractional frequency vibration sensitivities (δf ₀/f₀) are on the order of several parts in 10^-9/g. Because the percentage bandwidth and order (number of poles) of the filters was fairly constant, so was the product of the center frequency and group delay. Thus, the fractional frequency vibration sensitivity of the filters can be expressed alternatively as carrier signal phase sensitivity to vibration. The τ-ω₀ product for the filters that were tested was on the order of 300 rad, so that the equivalent phase sensitivity to vibration was approximately 1 grad/g     

Energetic considerations for managing double-crested cormorants on Lake Champlain

We studied foraging distribution, activity budgets, fish consumption, and energetics of double-crested cormorants (Phalacrocorax auritus) at two breeding colonies on Lake Champlain. Our objective was to determine if fish consumption and distribution of predation changed with movements of cormorants associated with efforts to reduce numbers of cormorants on one of the colonies. Wildlife managers reduced populations of cormorants on Young Island, Vermont by oiling their eggs, which resulted in dispersal of breeding cormorants 35 km south to Four Brothers Islands, New York. We found that as cormorants shifted from Young Island to the colony on Four Brothers Islands, energy demands, foraging distribution, and total fish consumption increased. Birds on Four Brothers Islands foraged a greater distance from the colony compared to birds on Young Island. Additionally, consumption of yellow perch (Perca flavescens) shifted to rainbow smelt (Osmerus mordax) when more birds bred on Four Brothers Islands. The dispersal of cormorants from Young Island to Four Brothers Islands reduced predation on yellow perch but increased overall fish consumption. Our estimates of fish consumption ranged from 322,000–425,000 kg of fish per year at Young Island to 899,000–1,086,000 kg of fish per year at Four Brothers Islands. Results from this study demonstrate secondary impacts of management on Young Island to unmanaged areas.