219 research outputs found
Gaseous Hydrocarbon Separations Using Functionalized Ionic Liquids
International audienceThe functionalization of the side chains on the cation or the anion of an ionic liquid is a common approach to tailor its properties for different processes including the separation of gases. In this paper, we present the current state of the art concerning the usage of ionic liquids for hydrocarbon separations. We also show how the functionalization of ionic liquids or the appropriate anion/cation combinations can contribute to the increase of the performance of the ionic liquids for the separation of gaseous hydrocarbons – either by improving the capacity of the ionic liquid to absorb a given gas or by increasing the selectivity towards a particular hydrocarbon. Original results concerning the usage of olefin-complexing metal salts of lithium (I), nickel (II) and copper (II) dissolved in ionic liquids for selectively absorbing light olefins are presented. It is observed that the absorption capacity of an imidazolium-based ionic liquid is doubled by the addition of a copper (II) salt. This result is compared with the effect of the functionalization of the ionic liquid and the advantages and difficulties of the two approaches are analyzed.La fonctionnalisation des chaînes latérales sur le cation ou l’anion d’un liquide ionique est une approche commune pour adapter ses propriétés pour les différents processus, y compris la séparation de gaz. Dans cet article, nous présentons l’état actuel des recherches concernant l’utilisation de liquides ioniques pour les séparations d’hydrocarbures gazeux. Nous montrons comment la fonctionnalisation de liquides ioniques ou des combinaisons d’anions/cations appropriées peuvent contribuer à l’augmentation de leur performance pour la séparation des hydrocarbures gazeux – soit par l’amélioration de la capacité du liquide ionique pour absorber un gaz donné ou en augmentant la sélectivité pour un hydrocarbure particulier. Des résultats originaux concernant l’utilisation de sels métalliques de lithium (I), le nickel (II) et le cuivre (II) dissous dans des liquides ioniques pour absorber sélectivement des oléfines légères sont présentés. On constate que la capacité d’absorption d’un liquide ionique à base d’imidazolium est doublée par addition d’un sel de cuivre (II). Ce résultat est comparé avec l’effet de la fonctionnalisation du liquide ionique. Les avantages et les difficultés de ces deux approches sont analysés
Signal Transmission Across Tile Assemblies: 3D Static Tiles Simulate Active Self-Assembly by 2D Signal-Passing Tiles
The 2-Handed Assembly Model (2HAM) is a tile-based self-assembly model in
which, typically beginning from single tiles, arbitrarily large aggregations of
static tiles combine in pairs to form structures. The Signal-passing Tile
Assembly Model (STAM) is an extension of the 2HAM in which the tiles are
dynamically changing components which are able to alter their binding domains
as they bind together. For our first result, we demonstrate useful techniques
and transformations for converting an arbitrarily complex STAM tile set
into an STAM tile set where every tile has a constant, low amount of
complexity, in terms of the number and types of ``signals'' they can send, with
a trade off in scale factor.
Using these simplifications, we prove that for each temperature
there exists a 3D tile set in the 2HAM which is intrinsically universal for the
class of all 2D STAM systems at temperature (where the STAM does
not make use of the STAM's power of glue deactivation and assembly breaking, as
the tile components of the 2HAM are static and unable to change or break
bonds). This means that there is a single tile set in the 3D 2HAM which
can, for an arbitrarily complex STAM system , be configured with a
single input configuration which causes to exactly simulate at a scale
factor dependent upon . Furthermore, this simulation uses only two planes of
the third dimension. This implies that there exists a 3D tile set at
temperature in the 2HAM which is intrinsically universal for the class of
all 2D STAM systems at temperature . Moreover, we show that for each
temperature there exists an STAM tile set which is intrinsically
universal for the class of all 2D STAM systems at temperature ,
including the case where .Comment: A condensed version of this paper will appear in a special issue of
Natural Computing for papers from DNA 19. This full version contains proofs
not seen in the published versio
Dried Tomato-Flavored Probiotic Cream Cheese with Lactobacillus paracasei
A dried tomato-flavored probiotic cream cheese (P) containing Lactobacillus paracasei Lpc-37 was developed for the purpose of this study. The same product, but without probiotic addition (C) was used as control. Lactococcus lactis subsp. lactis and Lactococcus lactis subsp. cremoris were used as lactic starter cultures. Chemical composition analyses and sensory tests were performed on days 1 and 7, respectively. Titratable acidity, pH value and L. paracasei population were determined every 7 d during the refrigerated storage (21 d) of the cream cheeses. The experiment and analyses were performed in triplicate, using standard methods. Probiotic population remained greater than 10(7) CFU/g throughout the storage period, thereby characterizing the product as potentially probiotic. Cream cheeses C and P did not differ on the sensory tests, both obtaining good overall acceptance by the consumers, of which 82.6% stated that they certainly or probably would buy the product.Univ. Norte do Parana (UNOPAR)Univ. Norte do Parana (UNOPAR)Fundacao Nacional de Desenvolvimento do Ensino Superior Particular (FUNADESP)Fundacao Nacional de Desenvolvimento do Ensino Superior Particular (FUNADESP
Cosmological Parameters from the 2003 flight of BOOMERANG
We present the cosmological parameters from the CMB intensity and
polarization power spectra of the 2003 Antarctic flight of the BOOMERANG
telescope. The BOOMERANG data alone constrains the parameters of the
CDM model remarkably well and is consistent with constraints from a
multi-experiment combined CMB data set. We add LSS data from the 2dF and SDSS
redshift surveys to the combined CMB data set and test several extensions to
the standard model including: running of the spectral index, curvature, tensor
modes, the effect of massive neutrinos, and an effective equation of state for
dark energy. We also include an analysis of constraints to a model which allows
a CDM isocurvature admixture.Comment: 18 pages, 10 figures, submitted to Ap
A Measurement of the Angular Power Spectrum of the CMB Temperature Anisotropy from the 2003 Flight of Boomerang
We report on observations of the Cosmic Microwave Background (CMB) obtained
during the January 2003 flight of Boomerang . These results are derived from
195 hours of observation with four 145 GHz Polarization Sensitive Bolometer
(PSB) pairs, identical in design to the four 143 GHz Planck HFI polarized
pixels. The data include 75 hours of observations distributed over 1.84% of the
sky with an additional 120 hours concentrated on the central portion of the
field, itself representing 0.22% of the full sky. From these data we derive an
estimate of the angular power spectrum of temperature fluctuations of the CMB
in 24 bands over the multipole range (50 < l < 1500). A series of features,
consistent with those expected from acoustic oscillations in the primordial
photon-baryon fluid, are clearly evident in the power spectrum, as is the
exponential damping of power on scales smaller than the photon mean free path
at the epoch of last scattering (l > 900). As a consistency check, the
collaboration has performed two fully independent analyses of the time ordered
data, which are found to be in excellent agreement.Comment: 11 pages, 7 figures, 3 tables. High resolution figures and data are
available at http://cmb.phys.cwru.edu/boomerang/ and
http://oberon.roma1.infn.it/boomerang/b2
Deep U band and R imaging of GOODS-South: Observations,data reduction and first results
We present deep imaging in the {\em U} band covering an area of 630
arcmin centered on the southern field of the Great Observatories Origins
Deep Survey (GOODS). The data were obtained with the VIMOS instrument at the
ESO Very Large Telescope. The final images reach a magnitude limit (AB, 1, in a 1\arcsec radius aperture), and have good
image quality, with full width at half maximum \approx 0.8\arcsec. They are
significantly deeper than previous U--band images available for the GOODS
fields, and better match the sensitivity of other multi--wavelength GOODS
photometry. The deeper U--band data yield significantly improved photometric
redshifts, especially in key redshift ranges such as , and deeper
color--selected galaxy samples, e.g., Lyman--break galaxies at . We
also present the coaddition of archival ESO VIMOS R band data, with (AB, 1, 1\arcsec radius aperture), and image quality
\approx 0.75 \arcsec. We discuss the strategies for the observations and data
reduction, and present the first results from the analysis of the coadded
images.Comment: Accepted for publication ApJS, 54 pages, 27 figures. Released data
and full-quality paper version available at
http://archive.eso.org/cms/eso-data/data-packages/goods-vimos-imaging-data-release-version-1.
Searching for non Gaussian signals in the BOOMERanG 2003 CMB maps
We analyze the BOOMERanG 2003 (B03) 145 GHz temperature map to constrain the
amplitude of a non Gaussian, primordial contribution to CMB fluctuations. We
perform a pixel space analysis restricted to a portion of the map chosen in
view of high sensitivity, very low foreground contamination and tight control
of systematic effects. We set up an estimator based on the three Minkowski
functionals which relies on high quality simulated data, including non Gaussian
CMB maps. We find good agreement with the Gaussian hypothesis and derive the
first limits based on BOOMERanG data for the non linear coupling parameter f_NL
as -300<f_NL<650 at 68% CL and -800<f_NL<1050 at 95% CL.Comment: accepted for publication in ApJ. Letter
Subdegree Sunyaev-Zel'dovich Signal from Multifrequency BOOMERanG observations
The Sunyaev-Zel'dovich (SZ) effect is the inverse Compton-scattering of
cosmic microwave background (CMB) photons by hot electrons in the intervening
gas throughout the universe. The effect has a distinct spectral signature that
allows its separation from other signals in multifrequency CMB datasets. Using
CMB anisotropies measured at three frequencies by the BOOMERanG 2003 flight we
constrain SZ fluctuations in the 10 arcmin to 1 deg angular range. Propagating
errors and potential systematic effects through simulations, we obtain an
overall upper limit of 15.3 uK (2 sigma) for rms SZ fluctuations in a broad bin
between multipoles of of 250 and 1200 at the Rayleigh-Jeans (RJ) end of the
spectrum. When combined with other CMB anisotropy and SZ measurements, we find
that the local universe normalization of the density perturbations is
sigma-8(SZ) < 0.96 at the 95% confidence level, consistent with sigma-8
determined from primordial perturbations.Comment: accepted for publication in ApJ. Letter
The role of GRK6 in animal models of Parkinson's Disease and L-DOPA treatment
G protein-coupled Receptor Kinase 6 (GRK6) belongs to a family of kinases that phosphorylate GPCRs. GRK6 levels were found to be altered in Parkinson's Disease (PD) and D2 dopamine receptors are supersensitive in mice lacking GRK6 (GRK6-KO mice). To understand how GRK6 modulates the behavioral manifestations of dopamine deficiency and responses to L-DOPA, we used three approaches to model PD in GRK6-KO mice: 1) the cataleptic response to haloperidol; 2) introducing GRK6 mutation to an acute model of absolute dopamine deficiency, DDD mice; 3) hemiparkinsonian 6-OHDA model. Furthermore, dopamine-related striatal signaling was analyzed by assessing the phosphorylation of AKT/GSK3β and ERK1/2. GRK6 deficiency reduced cataleptic behavior, potentiated the acute effect of L-DOPA in DDD mice, reduced rotational behavior in hemi-parkinsonian mice, and reduced abnormal involuntary movements induced by chronic L-DOPA. These data indicate that approaches to regulate GRK6 activity could be useful in modulating both therapeutic and side-effects of L-DOPA
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