A column of alumina modified with sodium dodecyl sulfate (SDS) and dimethylglyoxime (DMG) was prepared for the preconcentration of trace nickel from water samples for flame atomic absorption spectrometry (FAAS) determinations. Under optimized conditions (pH=7.0; flow rate: 20 mlmin-1) nickel was retained on the column. The nickel collected on the column was eluted with 5 mL of 1 M nitric ac...

We obtained X-ray spectra of the Seyfert 1 galaxy NGC 3516 in March 1995 using the Japanese X-ray satellite ASCA. Simultaneous far-UV observations were obtained with the Hopkins Ultraviolet Telescope on the Astro-2 shuttle mission. The ASCA spectrum shows a lightly absorbed power law of energy index 0.78. The low energy absorbing column is signiicantly less than previously seen. Prominent O vii...

We discuss the detection of absorption by interstellar hydrogen fluoride (HF) along the sight line to the submillimeter continuum sources W49N and W51. We have used Herschel’s HIFI instrument in dual beam switch mode to observe the 1232.4762 GHz J = 1−0 HF transition in the upper sideband of the band 5a receiver. We detected foreground absorption by HF toward both sources over a wide range of v...

Using the extremely high S/N quasar absorption-line sample described in the first paper of the series, we investigate which intergalactic C IV absorption line systems could be directly associated with galactic outflows at z = 2 − 3.5 from an analysis of the velocity widths of the C IV absorption line systems. Only about half the systems with a peak τ(CIV) above 0.4 in the λ1548 Å line (roughly ...

Prediction of the soft X-ray absorption along lines of sight through our Galaxy is crucial for understanding the spectra of extragalactic sources, but requires a good estimate of the foreground column density of photoelectric absorbing species. Assuming uniform elemental abundances this reduces to having a good estimate of the total hydrogen column density, NHtot = NH I + 2NH2 . The atomic comp...

In this research, the reactive absorption of carbon dioxide in an aqueous solution of NH3, H2O, and NaOH has experimentally been investigated. The experiments were carried out in an absorption pilot plant in different operational conditions. The composition and temperature of both gas and liquid phases were obtained during the column height. The concentration of molecular ...

The physical conditions within damped Lyα systems (DLAs) can reveal the star formation history, determine the chemical composition of the associated ISM, and hence document the first steps in the formation of present day galaxies. Here we present calculations that self-consistently determine the gas ionization, level populations (atomic fine-structure levels and rotational levels of H2), grain ...

We re-analyze the HST high resolution spectroscopic data of the intrinsic absorber in NGC 5548 and find that the C iv absorption column density is at least four times larger than previously determined. This increase arises from accounting for the kinematical nature of the absorber and from our conclusion that the outflow does not cover the narrow emission line region in this object. The improve...