127 resultados para Compatible solutes
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This article examines Pierre Bourdieu's sociology of the economy and his more recent politically engaged interventions on 'globalisation'. Many scholars regard these as not being in the same academic league as his classic studies on taste, academia, and state elites, etc., and, instead, dismiss them as a private matter or even, as the spleen of Pierre Bourdieu, the individual. This paper questions this disjunction of the 'academic' and 'politically engaged' sides of Pierre Bourdieu's work. First, it argues that his most recent interventions against a neo-liberal globalisation were the logical result of a particular definition of intellectual practice that had been outlined before in his sociology of the intellectual field. It then demonstrates that Bourdieu's economic sociology and critique of contemporary capitalism not only does not contradict his earlier research, but that it provides valuable and original insights into the current transformation of the political economy of the advanced capitalist countries. The paper concludes with a suggestion of how to strengthen the theoretical foundation of Bourdieu's analysis of contemporary capitalism by relating it to and making it compatible with alternative approaches in the tradition of critical political economy.
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There is currently a need to expand the range of graft materials available to orthopaedic surgeons. This study investigated the effect of ternary phosphate based glass (PBG) compositions on the behaviour of osteoblast and osteoblast-like cells. PBGs of the formula in mol% P2O5 (50)-CaO (50-X)-Na2O (X), where X was either 2, 4, 6, 8 or 10 were produced and their influence on the proliferation, differentiation and death in vitro of adult human bone marrow stromal cells (hBMSCs) and human fetal osteoblast 1.19 (HFOB 1.19) cells were assessed. Tissue culture plastic (TCP) and hydroxyapatite (HA) were used as controls. Exposure to PBGs in culture inhibited cell adhesion, proliferation and increased cell death in both cell types studied. There was no significant difference in %cell death between the PBGs which was significantly greater than the controls. However, compared to other PBGs, a greater number of cells was found on the 48 mol% CaO which may have been due to either increased adherence, proliferation or both. This composition was capable of supporting osteogenic proliferation and early differentiation and supports the notion that chemical modification of the glass could to lead to a more biologically compatible substrate with the potential to support osteogenic grafting. Realisation of this potential should lead to the development of novel grafting strategies for the treatment of problematic bone defects.
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Conducting polypyrrole is a biological compatible polymer matrix wherein number of drugs and enzymes can be incorporated by way of doping. The polypyrrole, which is obtained as freestanding film by electrochemical polymerization, has gained tremendous recognition as sophisticated electronic measuring device in the field of sensors and drug delivery. In drug delivery the reversing of the potential 100% of the drug can be released and is highly efficient as a biosensor in presence of an enzyme. In this review we discuss the applications of conducting polypyrrole as biosensor for some biomolecules and drug delivery systems.
An exploratory non-LTE model atmosphere analysis of B-type supergiants in the Small Magellanic Cloud
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A preliminary differential non-LTE model atmosphere analysis of moderate resolution (R ~ 5 000) and signal-to-noise ratio spectra of 48 Small Magellanic Cloud B-type supergiants is presented. Standard techniques are adopted, viz. plane-parallel geometry and radiative and hydrostatic equilibrium. Spectroscopic atmospheric parameters (T_eff, log g and v_turb), luminosities and chemical abundances (He, C, N, O, Mg and Si) are estimated. These are compared with those deduced for a comparable sample of Galactic supergiants. The SMC targets appear to have similar atmospheric parameters, luminosities and helium abundances to the Galactic sample. Their magnesium and silicon underabundances are compatible with those found for main sequence SMC objects and there is no evidence for any large variation in their oxygen abundances. By contrast both their carbon and nitrogen lines strengths are inconsistent with single abundances, while their nitrogen to carbon abundance ratios appear to vary by at least as much and probably more than that found in the Galactic sample.
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Surface water and deep and shallow groundwater samples were taken from selected parts of the Grand-Duchy of Luxembourg to determine the isotopic composition of nitrate and sulfate, in order to identify sources and/or processes affecting these solutes. Deep groundwater had sulfate concentrations between 20 and 40 mg/L, d34Ssulfate values between -3.0 and -20.0‰, and d18Osulfate values between +1.5 and +5.0‰; nitrate was characterized by concentrations varying between
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Aims. The aim of this work is to constrain the size, composition and surface properties of asteroids (2867) Steins and (21) Lutetia, targets of the Rosetta mission. Rosetta is en route to rendezvous with comet 67P/Churyumov-Gerasimenko.
Methods. Thermal-Infrared N-band observations for Lutetia and Steins were obtained using, respectively, TIMMI2 on the ESO 3.6-m telescope at La Silla and VISIR at the UT3 VLT telescope on Cerro Paranal; visible light curves for Steins were obtained using NTT+SUSI2, while R-band photometry for Lutetia was obtained with the 2.0-m Faulkes Telescope North on Haleakala. For Steins, the NEATM model was used to constrain its visible geometric albedo and beaming parameter. A detailed thermophysical model was implemented and used to analyze our set of observations of Lutetia as well as previous reported measurements.
Results. The visible photometry of Steins was used along with data from the literature to yield a slope parameter of G=0.32(-0.11)(+0.14). Problems during the observations led to the loss of measurements on two of the three N-band filters requested for Steins. Using the remaining data and the polarimetric albedo recently published, we were able to constrain the thermal beaming parameter as eta > 1.2, which is more similar to near-Earth asteroids and suggests either high thermal inertia or a very rough surface. For Lutetia, the best fit visible geometric albedo obtained with our model and the reported observation is p(nu)=0.129, significantly lower than that obtained if one applies the same model to previously reported measurements. The discrepancy cannot be explained solely by assuming inhomogeneities in the surface properties and we suggest that the most plausible explanation is the presence of one or more large craters on the northern hemisphere. For both sets of measurements, the implied single scattering albedo of Lutetia is compatible with laboratory measurements of carbonaceous chondrite meteorites.
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Both the existence and the non-existence of a linearly ordered (by certain natural order relations) effective set of comparison functions (=dense comparison classes) are compatible with the ZFC axioms of set theory.
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A World Conservation Union (IUCN) regional red list is an objective assessment of regional extinction risk and is not the same as a list of conservation priority species. Recent research reveals the widespread, but incorrect, assumption that IUCN Red List categories represent a hierarchical list of priorities for conservation action. We developed a simple eight-step priority-setting process and applied it to the conservation of bees in Ireland. Our model is based on the national red list but also considers the global significance of the national population; the conservation status at global, continental, and regional levels; key biological, economic, and societal factors; and is compatible with existing conservation agreements and legislation. Throughout Ireland, almost one-third of the bee fauna is threatened (30 of 100 species), but our methodology resulted in a reduced list of only 17 priority species. We did not use the priority species list to broadly categorize species to the conservation action required; instead, we indicated the individual action required for all threatened, near-threatened, and data-deficient species on the national red list based on the IUCN's conservation-actions template file. Priority species lists will strongly influence prioritization of conservation actions at national levels, but action should not be exclusive to listed species. In addition, all species on this list will not necessarily require immediate action. Our method is transparent, reproducible, and readily applicable to other taxa and regions.
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This Account describes experimental data used to understand the structure of ionic liquids and solute-solvent interactions of both molecular solutes and dissolved metal complexes. In general, the structures of the ionic liquids determined from experimental data show good agreement with both simulated structures and solid-state structures. For all ionic liquids studied, strong charge ordering is found leading to long-range order even in the presence of a solute. For dissolved metal complexes, the ionic liquid is not innocent and a clear dependence on the speciation is observed with variations in both the cation and anion.
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In his provocative article, F. Mechsner (2004) advances the thesis that human voluntary movements are subject to "psychological" or "perceptual -cognitive" control and are thus organized "without regard to efferent patterns" (p. 355). Rather than considering in detail the experiments that he proffered by way of support, the present author discusses the degree to which that supposition has appeal on the grounds of simplicity and is defined in terms that are compatible with a unified science.
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Context: The masses previously obtained for the X-ray binary 2S 0921-630 inferred a compact object that was either a high-mass neutron star or low-mass black-hole, but used a previously published value for the rotational broadening (v sin i) with large uncertainties. Aims: We aim to determine an accurate mass for the compact object through an improved measurement of the secondary star's projected equatorial rotational velocity. Methods: We have used UVES echelle spectroscopy to determine the v sin i of the secondary star (V395 Car) in the low-mass X-ray binary 2S 0921-630 by comparison to an artificially broadened spectral-type template star. In addition, we have also measured v sin i from a single high signal-to-noise ratio absorption line profile calculated using the method of Least-Squares Deconvolution (LSD). Results: We determine v sin i to lie between 31.3±0.5 km s-1 to 34.7±0.5 km s-1 (assuming zero and continuum limb darkening, respectively) in disagreement with previous results based on intermediate resolution spectroscopy obtained with the 3.6 m NTT. Using our revised v sin i value in combination with the secondary star's radial velocity gives a binary mass ratio of 0.281±0.034. Furthermore, assuming a binary inclination angle of 75° gives a compact object mass of 1.37±0.13 M_?. Conclusions: We find that using relatively low-resolution spectroscopy can result in systemic uncertainties in the measured v sin i values obtained using standard methods. We suggest the use of LSD as a secondary, reliable check of the results as LSD allows one to directly discern the shape of the absorption line profile. In the light of the new v sin i measurement, we have revised down the compact object's mass, such that it is now compatible with a canonical neutron star mass.
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The effect of the addition of acetonitrile on the solubility of carbon dioxide in an ionic liquid, the 1-ethyl-3- methylimidazolium bis(trifluoromethanesulfonyl)amide, [C(2)mim][NTf2], was studied experimentally at pressures close to atmospheric and as a function of temperature between 290 and 335 K. It was observed that the solubility of carbon dioxide decreases linearly with the mole fraction of acetonitrile from a value of 2.6 x 10(-2) in the pure ionic liquid at 303 K to a mole fraction of 1.3 x 10(-2) in the mixture [C(2)mim][NTf2] + CH3CN with x(CH3CN) = 0.77 at the same temperature. The gas solubility decreases with temperature, and the thermodynamic properties of solvation could be calculated. The vapor pressures of the [ C2mim][ NTf2] + CH3CN mixtures were measured in the same temperature range, and strong negative deviations from Raoult's law were obtained: up to 36% for a mixture with x(CH3CN) = 0.46 at 334 K. Negative excess molar volumes of approximately -1 cm(3) mol(-1) at equimolar composition could also be calculated from density measurements of the pure components and of the mixtures. These observations are confirmed by neutron diffraction studies and are compatible with the existence of strong ion-dipole interactions in the mixed liquid solvent.
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Numerical simulations are used to study the electromagnetic scattering from phase agile microstrip reflectarray cells which exploit the voltage controlled dielectric anisotropy property of nematic state liquid crystals (LC). In the computer model two arrays of equal size elements constructed on a 15?m thick tuneable LC layer were designed to operate at centre frequencies of 102 GHz and 130 GHz. Micromachining processes based on the metallization of quartz/silicon wafers and an industry compatible LCD packaging technique were employed to fabricate the grounded periodic structures. The loss and phase of the reflected signals were measured using a quasi-optical test bench with the reflectarray cells inserted at the beam waist of the imaged Gaussian beam, thus eliminating some of the major problems associated with traditional free-space characterisation at these frequencies. By applying a low frequency AC bias voltage of 10 V, a 165o phase shift with a loss 4.5 dB-6.4 dB at 102 GHz and 130o phase shift with a loss variation between 4.3 dB – 7 dB at 130 GHz was obtained. The experimental results are shown to be in close agreement with the computer model.
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Periodically loaded dipole arrays printed on grounded dielectric substrate are shown to exhibit left-handed propagation properties. In an equivalent transmission line representation, lefthandedness emerges due to the excess series capacitance and shunt inductance. Based on this concept, the authors study the distribution of the modal fields and the variation of series capacitance and shunt inductance as the dipoles are loaded with stubs. Full wave dispersion curves that show the gradual transition from a right-handed to a left-handed medium upon periodically loading the dipoles with stubs are presented. An equivalent circuit is derived that matches to a very good extent the full wave result. The cell dimensions are a small fraction of the wavelength (),15), so the structure can be considered as an equivalent homogeneous surface. The structure is simple, readily scalable to higher frequencies and compatible with low-cost fabrication techniques.
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This paper presents an efficient. modeling technique for the derivation of the dispersion characteristics of novel uniplanar metallodielectric periodic structures. The analysis is based on the method of moments and an interpolation scheme, which significantly accelerates the computations. Triangular basis functions are used that allow for modeling of arbitrary shaped metallic elements. Based on this method, novel uniplanar left-handed (LH) metamaterials are proposed. Variations of the split rectangular-loop element printed on grounded dielectric substrate are demonstrated to possess LH propagation properties. Full-wave dispersion curves are presented. Based on the dual transmission-line concept, we study the distribution of the modal fields And the variation of series capacitance and shunt inductance for all the proposed elements. A verification of the left-handedness is presented by means of full-wave simulation of finite uniplanar arrays using commercial software (HFSS). The cell dimensions are a small fraction of the wavelength (approximately lambda/24) so that the structures can he considered as a homogeneous effective medium. The structures are simple, readily scalable to higher frequencies, and compatible with low-cost fabrication techniques.