Laser operation at 2.8 microm in BaY(2)F(8) with erbium concentrations of 7.5% and 20% is investigated under laser-diode pumping at 967 nm. Output powers as high as 250 mW and slope efficiencies as high as 24% are obtained. Results are comparable with those of Er(3+):LiYF(4) under the same pump conditions. Slope efficiencies above 30% are predicted for optimized erbium concentrations.

In our study, we analyzed the combined standard uncertainty of water table slope assessment done using differential global positioning system (DGPS)-based measurements of water table elevation and distances between measurement locations. We compared and discussed uncertainties in water table slope assessments done in various hypothetical environments of lowland floodplains (water table slopes t...

For the last few years the Cold Dark Matter model (ticker: CDM), has been the dominant theory of structure formation. We briefly review the recent advancements and predictions of the model in the field of galaxy clusters. A new set of very high resolution simulations of galaxy clusters show that they have (1) density profiles with central slopes very close to −1.6 and (2) abundance of subhalos ...

Neurons in the visual cortex respond selectively to stimulus orientation and spatial frequency. Changes in response amplitudes of these neurons could be the neurophysiological basis of orientation and spatial frequency discrimination. We have estimated the minimum differences in stimulus orientation and spatial frequency that can produce reliable changes in the responses of individual neurons i...

A technique to detect residual tetracyclines (TCs) in honey by HPLC and derivative UV-Vis spectra is examined in this study. Chromatograms of honey products often experience overlapped peaks and sloping background due to similar retention properties of components or to the presence of impurities. The derivatives provide resolution of overlapped peaks in an UV-Vis spectrum and eventually bring c...

Paintings are the product of a process that begins with ordinary vision in the natural world and ends with manipulation of pigments on canvas. Because artists must produce images that can be seen by a visual system that is thought to take advantage of statistical regularities in natural scenes, artists are likely to replicate many of these regularities in their painted art. We have tested this ...

[1] The role of low-level transpacific paths in bringing east Asian air to the North American west coast surface is determined using conditional transit-time distributions. These distributions are computed with the MATCH transport model driven by NCEP reanalysis data. Transpacific paths that lie entirely below 2.2 km contribute negligibly to the west coast column burden of east Asian air. Howev...

Attenborough’s long-beaked echidna Zaglossus attenboroughi is known from a single specimen collected in the Cyclops Mountains of northern Papua in 1961, and has previously been considered to be extremely rare if not already extinct. New fieldwork to investigate the continued survival of Z. attenboroughiwas conducted on the north and south slopes of the Cyclops Mountains in May 2007 using commun...

This paper examines the possibility of estimating basilar-membrane (BM) nonlinearity using a psychophysical technique. The level of a forward masker required to mask a brief signal was measured for conditions where the masker was either at, or one octave below, the signal frequency. The level of the forward masker at masked threshold provided an indirect measure of the BM response to the signal...