360 research outputs found
The ERE of the "Red Rectangle" revisited
We present in this paper high signal-to-noise long-slit optical spectra of
the Extended Red Emission (ERE) in the "Red Rectangle" (RR) nebula. These
spectra, obtained at different positions in the nebula, reveal an extremely
complex emission pattern on top of the broad ERE continuum. It is well known
that three features converge at large distance from the central object, in
wavelength and profile to the diffuse interstellar bands (DIBs) at 5797, 5849.8
and 6614 ang., (e.g. Sarre et al., 1995). In this paper we give a detailed
inventory of all spectral subfeatures observed in the 5550--6850 ang. spectral
range. Thanks to our high S/N spectra, we propose 5 new features in the RR that
can be associated with DIBs. For the 5550--6200 ang. spectral range our slit
position was on top of the NE spike of the X shaped nebula. A detailed
description of the spatial profile-changes is given of the strongest features
revealing that even far out in the nebula at 24 arcsec from the central star,
there remains a small shift in wavelength of 1 respectively 2 ang between the
ERE subfeatures and the DIB wavelengths of 5797.11 and 5849.78 ang.Comment: 8 pages, 9 figures accepted by Astronomy and Astrophysic
Sequence structure emission in The Red Rectangle Bands
We report high resolution (R~37,000) integral field spectroscopy of the
central region (r<14arcsec) of the Red Rectangle nebula surrounding HD44179.
The observations focus on the 5800A emission feature, the bluest of the
yellow/red emission bands in the Red Rectangle. We propose that the emission
feature, widely believed to be a molecular emission band, is not a molecular
rotation contour, but a vibrational contour caused by overlapping sequence
bands from a molecule with an extended chromophore. We model the feature as
arising in a Polycyclic Aromatic Hydrocarbon (PAH) with 45-100 carbon atoms.Comment: 13 pages, 9 figures, accepted for publication in ApJ. A version of
the paper with full resolution figures is available at:
http://www.aao.gov.au/local/www/rgs/Sequence-Structure
Current assessment of the Red Rectangle band problem
In this paper we discuss our insights into several key problems in the
identification of the Red Rectangle Bands (RRBs). We have combined three
independent sets of observations in order to try to define the constraints
guiding the bands. We provide a summary of the general behavior of the bands
and review the evidence for a molecular origin of the bands. The extent,
composition, and possible absorption effects of the bands are discussed.
Comparison spectra of the strongest band obtained at three different spectral
resolutions suggests that an intrinsic line width of individual rotational
lines can be deduced. Spectroscopic models of several relatively simple
molecules were examined in order to investigate where the current data are
weak. Suggestions are made for future studies to enhance our understanding of
these enigmatic bands
GALEX FUV Observations of Comet C/2004 Q2 (Machholz): The Ionization Lifetime of Carbon
We present a measurement of the lifetime of ground state atomic carbon,
C(^3P), against ionization processes in interplanetary space and compare it to
the lifetime expected from the dominant physical processes likely to occur in
this medium. Our measurement is based on analysis of a far ultraviolet (FUV)
image of comet C/2004 Q2 (Machholz) recorded by the Galaxy Evolution Explorer
(GALEX) on 2005 March 1. The bright CI 1561 A and 1657 A multiplets dominate
the GALEX FUV band. We used the image to create high S/N radial profiles that
extended beyond one million km from the comet nucleus. Our measurements yielded
a total carbon lifetime of 7.1 -- 9.6 x 10^5 s (scaled to 1 AU). Which compares
favorably to calculations assuming solar photoionization, solar wind proton
change exchange and solar wind electron impact ionization are the dominant
processes occurring in this medium and that comet Machholz was embedded in the
slow solar wind. The shape of the CI profiles inside 3x10^5 km suggests that
either the CO lifetime is shorter than previously thought and/or a
shorter-lived carbon-bearing parent molecule, such as CH_4 is providing the
majority of the carbon in this region of the coma of comet Machholz.Comment: 26 pages, 6 figures, accepted for publication in the Astrophysical
Journa
Chemical and biological evaluation of rejects from the wood industry.
Este estudo visa a caracterização química e a avaliação da atividade antimicrobiana de extratos obtidos a partir de rejeitos resultantes do beneficiamento de madeiras nobres comercializadas no Paraná: Peroba-Rosa (Aspidosperma sp.), Roxinho (Peltogyne sp.), Jatobá (Hymenaea sp.), Curupixá (Micropholis sp.), Itaúba (Mezilaurus sp.), Cedrilho (Erisma sp.) e Imbúia-do-Norte (Licaria sp.), cujas identificações botânicas basearam-se em estudos anatômicos. Os extratos foram preparados com diversos solventes, analisados por CCD e espectrometria UV/VIS, testando-se contra: Proteus mirabilis ATCC15290, Escherichia coli ATCC25922, Enterobacter aerogenes ATCC13048, Staphylococcus aureus ATCC25923, Micrococcus luteus ATCC9341, Klebsiella pneumoniae ATCC13883, Pseudomonas aeroginosa ATCC27853, e Staphylococcus aureus, Streptococcus mutans e Bacillus cereus isolados da clínica. O extrato etanólico de Peroba-Rosa, contendo alcalóides, apresentou atividade contra P. mirabilis. Os extratos metanólicos do Jatobá, Itaúba e Imbúia, contendo fenóis, e o extrato de Roxinho obtido com acetato de etila contendo fenóis e terpenóides, foram ativos contra K. pneumoniae, M. luteus, E. coli, S. aureus e P. mirabilis. Nenhum dos extratos foi ativo contra P. aeroginosa, S. mutans e E. aerogenes
INFORMATION LITERACY STRATEGY: A CASE STUDY OF THE MANAGEMENT DEPARTMENT AT THE U.S. COAST GUARD ACADEMY
Izazov akademskog istraživanja nije pronaći informacije nego odabrati, organizirati i procijeniti valjanost i pouzdanost dostupnih informacija. Ovaj rad predstavlja strategiju Informacijske pismenosti (IP) koja je razvijena za unaprjeđenje IP vještina u preddiplomskom programu na Odjelu za menadžment USCG akademije. Autori demonstriraju IP strategije unutar kolegija kojeg predaju i pokazuju kako integrirana IP strategija odgovara na obrazovne IP standarde i zahtjeve. Rad navodi IP vježbe koje su razvijene i korištene u sljedećim kolegijima: Principi makroekonomije (prva godina); Organizacijsko ponašanje i vodstvo (druga godina); Uvod u biznis (druga godina); Marketing (treća godina); i Sustavi upravljanja informacijama (treća godina). Svaki kolegij pružen unutar studija Menadžmenta služi kao model razvoja IP vještina koje su strukturirane za razvoj IP vještina sekvencijalno od prve do zadnje godine preddiplomskog programa.The challenge of academic research is not to find information but to select, organize, and evaluate the validity and reliability of the information available. The paper presents the Information Literacy (IL) strategy that has been developed for the advancement of IL skills in an undergraduate program in the Management Department at the USCG Academy. The authors demonstrate IL strategies within the coursework they teach and how an integrated IL strategy responds to educational IL standards and requirements. The paper lists the IL exercises that were developed and used in the following courses: Macroeconomics Principles (freshman level); Organizational Behavior and Leadership (sophomore level); Introduction to Business (sophomore level); Marketing (junior level); and Management Information Systems (junior level). Each course provided within Management major serves as a model for the development of the IL skills that are structured to develop the IL skills sequentially from freshman to senior year in an undergraduate program
Strategija informacijske pismenosti: primjer Odjela za menadžment na Američkoj akademiji obalne straže
The challenge of academic research is not to find information but to select, organize, and evaluate the validity and reliability of the information available. The paper presents the Information Literacy (IL) strategy that has been developed for the advancement of IL skills in an undergraduate program in the Management Department at the USCG Academy. The authors demonstrate IL strategies within the coursework they teach and how an integrated IL strategy responds to educational IL standards and requirements. The paper lists the IL exercises that were developed and used in the following courses: Macroeconomics Principles (freshman level); Organizational Behavior and Leadership (sophomore level); Introduction to Business (sophomore level); Marketing (junior level); and Management Information Systems (junior level). Each course provided within Management major serves as a model for the development of the IL skills that are structured to develop the IL skills sequentially from freshman to senior year in an undergraduate program.Izazov akademskog istraživanja nije pronaći informacije nego odabrati, organizirati i procijeniti valjanost i pouzdanost dostupnih informacija. Ovaj rad predstavlja strategiju Informacijske pismenosti (IP) koja je razvijena za unaprjeđenje IP vještina u preddiplomskom programu na Odjelu za menadžment USCG akademije. Autori demonstriraju IP strategije unutar kolegija kojeg predaju i pokazuju kako integrirana IP strategija odgovara na obrazovne IP standarde i zahtjeve. Rad navodi IP vježbe koje su razvijene i korištene u sljedećim kolegijima: Principi makroekonomije (prva godina); Organizacijsko ponašanje i vodstvo (druga godina); Uvod u biznis (druga godina); Marketing (treća godina); i Sustavi upravljanja informacijama (treća godina). Svaki kolegij pružen unutar studija Menadžmenta služi kao model razvoja IP vještina koje su strukturirane za razvoj IP vještina sekvencijalno od prve do zadnje godine preddiplomskog programa
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