We consider the inverse problem of in-line holography, applied to minimally destructive imaging of cold atom clouds. Absorption imaging near resonance provides a simple, but destructive measurement of atom column density. Imaging off resonance greatly reduces heating, and sequential images may be taken. Under the conditions required for off-resonant imaging, the generally intractable inverse pr...

We present sub-arcsecond, Multi-Element Radio Linked Interferometer (MERLIN) observations of the decimetre radio continuum structure and neutral hydrogen (H) absorption from the nuclear region of the starburst galaxy NGC 4194 (the Medusa Merger). The continuum structure of the central kiloparsec of the Medusa has been imaged, revealing a pair of compact radio components surrounded by more diff...

The metal absorption lines found in association with Lyα absorbers of moderate to high HI column density contain valuable information about the metallicity and ionization conditions within the absorbers and offer a stronger test of models of the intergalactic medium at z ∼ 3 than HI absorption lines alone. We have developed a method to predict the strengths of metal absorption lines within the ...

We report on airborne CO(2) column absorption measurements made in 2009 with a pulsed direct-detection lidar operating at 1572.33 nm and utilizing the integrated path differential absorption technique. We demonstrated these at different altitudes from an aircraft in July and August in flights over four locations in the central and eastern United States. The results show clear CO(2) line shape a...

We searched for absorption lines of highly ionized O and Ne in the energy spectra of two Low-mass Xray binaries, 4U1820–303 in the globular cluster NGC6624 and Cyg X-2, observed with the Chandra LETG, and detected O VII, O VIII and Ne IX absorption lines for 4U1820–303. The equivalent width of the O VII Kα line was 1.19 +0.47 −0.30 eV (90 % errors) and the significance was 6.5 σ. Absorption lin...

In this study, optimization is carried out to find the optimized design of a foam-filled column for the best Specific Energy Absorption (SEA) and Crush Force Efficiency (CFE). In order to maximize SEA, the optimization gives the value of 2.3 for column thickness and 151.7 for foam length. On the other hand to maximize CFE, the optimization gives the value of 1.1 for column thickness and 200 for...

in this study, it was shown that how co2 and h2s were removed from a natural gas stream, using a nanofluid containing nanoporous graphene in diehanolamine (dea). before running the experiments, the appropriate values were chosen for the nanosheet dosage and the liquid and gas flow rates in the absorption experiments, which were performed in a laboratory scale wetted wall column. in the experime...

We observed the Seyfert 1 galaxy NGC 3516 twice during the ight of Astro-2 using the Hopkins Ultraviolet Telescope aboard the space shuttle Endeavour in March 1995. Simultaneous X-ray observations were performed with ASCA. Our far-ultraviolet spectra cover the spectral range 820{1840 A with a resolution of 2{4 A. No signiicant variations were found between the two observations. The total spectr...

We report on XMM-Newton spectroscopic observations of the luminous radio-quiet quasar PDS 456. The hard X-ray spectrum of PDS 456 shows a deep absorption trough (constituting 50% of the continuum) at energies above 7 keV in the quasar rest frame, which can be attributed to a series of blueshifted K-shell absorption edges due to highly ionized iron. The higher resolution soft X-ray Reflection Gr...