Dynamic wetting for continuum hydrodynamics with multi-component Lattice Boltzmann equation simulation method

This paper was presented at the 2nd Micro and Nano Flows Conference (MNF2009), which was held at Brunel University, West London, UK. The conference was organised by Brunel University and supported by the Institution of Mechanical Engineers, IPEM, the Italian Union of Thermofluid dynamics, the Process Intensification Network, HEXAG - the Heat Exchange Action Group and the Institute of Mathematics and its Applications.We present methodological innovations to the multi-component lattice Boltzmann equation simulation method which allow for the simulation of dynamic contact lines in the continuum approximation. The improvements are set-out and verified by quantitative results. They allow the simulator access to an expanded range of simulation parameters like viscosity, viscosity contrast and interfacial tensions, and to obtain data with low levels of interfacial micro-current activity in the region of the dynamic contact line

Detection of Voigt Spectral Line Profiles of Hydrogen Radio Recombination Lines toward Sagittarius B2(N)

We report the detection of Voigt spectral line profiles of radio recombination lines (RRLs) toward Sagittarius B2(N) with the 100-m Green Bank Telescope (GBT). At radio wavelengths, astronomical spectra are highly populated with RRLs, which serve as ideal probes of the physical conditions in molecular cloud complexes. An analysis of the Hn(alpha) lines presented herein shows that RRLs of higher principal quantum number (n>90) are generally divergent from their expected Gaussian profiles and, moreover, are well described by their respective Voigt profiles. This is in agreement with the theory that spectral lines experience pressure broadening as a result of electron collisions at lower radio frequencies. Given the inherent technical difficulties regarding the detection and profiling of true RRL wing spans and shapes, it is crucial that the observing instrumentation produce flat baselines as well as high sensitivity, high resolution data. The GBT has demonstrated its capabilities regarding all of these aspects, and we believe that future observations of RRL emission via the GBT will be crucial towards advancing our knowledge of the larger-scale extended structures of ionized gas in the interstellar medium (ISM)

The Spatial Distribution of Complex Organic Molecules in the L1544 Pre-stellar Core.

journal_title: The Astrophysical Journal article_type: paper article_title: THE SPATIAL DISTRIBUTION OF COMPLEX ORGANIC MOLECULES IN THE L1544 PRE-STELLAR CORE copyright_information: © 2016. The American Astronomical Society. All rights reserved. date_received: 2016-05-27 date_accepted: 2016-09-12 date_epub: 2016-10-05journal_title: The Astrophysical Journal article_type: paper article_title: THE SPATIAL DISTRIBUTION OF COMPLEX ORGANIC MOLECULES IN THE L1544 PRE-STELLAR CORE copyright_information: © 2016. The American Astronomical Society. All rights reserved. date_received: 2016-05-27 date_accepted: 2016-09-12 date_epub: 2016-10-05journal_title: The Astrophysical Journal article_type: paper article_title: THE SPATIAL DISTRIBUTION OF COMPLEX ORGANIC MOLECULES IN THE L1544 PRE-STELLAR CORE copyright_information: © 2016. The American Astronomical Society. All rights reserved. date_received: 2016-05-27 date_accepted: 2016-09-12 date_epub: 2016-10-05journal_title: The Astrophysical Journal article_type: paper article_title: THE SPATIAL DISTRIBUTION OF COMPLEX ORGANIC MOLECULES IN THE L1544 PRE-STELLAR CORE copyright_information: © 2016. The American Astronomical Society. All rights reserved. date_received: 2016-05-27 date_accepted: 2016-09-12 date_epub: 2016-10-05journal_title: The Astrophysical Journal article_type: paper article_title: THE SPATIAL DISTRIBUTION OF COMPLEX ORGANIC MOLECULES IN THE L1544 PRE-STELLAR CORE copyright_information: © 2016. The American Astronomical Society. All rights reserved. date_received: 2016-05-27 date_accepted: 2016-09-12 date_epub: 2016-10-05journal_title: The Astrophysical Journal article_type: paper article_title: THE SPATIAL DISTRIBUTION OF COMPLEX ORGANIC MOLECULES IN THE L1544 PRE-STELLAR CORE copyright_information: © 2016. The American Astronomical Society. All rights reserved. date_received: 2016-05-27 date_accepted: 2016-09-12 date_epub: 2016-10-05journal_title: The Astrophysical Journal article_type: paper article_title: THE SPATIAL DISTRIBUTION OF COMPLEX ORGANIC MOLECULES IN THE L1544 PRE-STELLAR CORE copyright_information: © 2016. The American Astronomical Society. All rights reserved. date_received: 2016-05-27 date_accepted: 2016-09-12 date_epub: 2016-10-05The detection of complex organic molecules (COMs) toward cold sources such as pre-stellar cores (with T<10 K), has challenged our understanding of the formation processes of COMs in the interstellar medium. Recent modelling on COM chemistry at low temperatures has provided new insight into these processes predicting that COM formation depends strongly on parameters such as visual extinction and the level of CO freeze out. We report deep observations of COMs toward two positions in the L1544 pre-stellar core: the dense, highly-extinguished continuum peak with A V ≥30 mag within the inner 2700 au; and a low-density shell with average A V ~7.5-8 mag located at 4000 au from the core's center and bright in CH3OH. Our observations show that CH3O, CH3OCH3 and CH3CHO are more abundant (by factors ~2-10) toward the low-density shell than toward the continuum peak. Other COMs such as CH3OCHO, c-C3H2O, HCCCHO, CH2CHCN and HCCNC show slight enhancements (by factors ≤3) but the associated uncertainties are large. This suggests that COMs are actively formed and already present in the low-density shells of pre-stellar cores. The modelling of the chemistry of O-bearing COMs in L1544 indicates that these species are enhanced in this shell because i) CO starts freezing out onto dust grains driving an active surface chemistry; ii) the visual extinction is sufficiently high to prevent the UV photo-dissociation of COMs by the external interstellar radiation field; and iii) the density is still moderate to prevent severe depletion of COMs onto grains

THE GOLDEN YEARS OF EASTERN OREGON

P. mi$$ion is granted to reprint infonl&apos;lCllion c:onfolned h.. ein. An

Global existence for semilinear reaction-diffusion systems on evolving domains

We present global existence results for solutions of reaction-diffusion systems on evolving domains. Global existence results for a class of reaction-diffusion systems on fixed domains are extended to the same systems posed on spatially linear isotropically evolving domains. The results hold without any assumptions on the sign of the growth rate. The analysis is valid for many systems that commonly arise in the theory of pattern formation. We present numerical results illustrating our theoretical findings.Comment: 24 pages, 3 figure

The Ultraviolet Imaging Telescope: Instrument and Data Characteristics

The Ultraviolet Imaging Telescope (UIT) was flown as part of the Astro observatory on the Space Shuttle Columbia in December 1990 and again on the Space Shuttle Endeavor in March 1995. Ultraviolet (1200-3300 Angstroms) images of a variety of astronomical objects, with a 40 arcmin field of view and a resolution of about 3 arcsec, were recorded on photographic film. The data recorded during the first flight are available to the astronomical community through the National Space Science Data Center (NSSDC); the data recorded during the second flight will soon be available as well. This paper discusses in detail the design, operation, data reduction, and calibration of UIT, providing the user of the data with information for understanding and using the data. It also provides guidelines for analyzing other astronomical imagery made with image intensifiers and photographic film.Comment: 44 pages, LaTeX, AAS preprint style and EPSF macros, accepted by PAS