Energetic evaluation of swing adsorption processes for CO2 capture in selected MOFs and zeolites: Effect of impurities

We present a systematic computational study of Mg-MOF-74, CuBTC and zeolite 13X for CO2 separation from multi-component flue gas mixtures. The impurities' impact was evaluated at the molecular level and process conditions. Adsorption isotherms and isosteric heats of adsorption of pure (CO2, N2, O2, H2O, SO2 and NO2) components, binary and ternary mixtures were obtained from Grand Canonical Monte Carlo simulations. Working capacities, purities, recoveries and exergetic performances were evaluated for VSA/PSA/TSA processes. Results show that NO2 has a negligible effect in the studied range. For H2O and SO2 the energy requirements are reduced as the impurity content increases and recovery and purity increase, up to an 'optimal' point where a competition for CO2 preferred adsorption sites produces a sharp drop in purity and the energetic index grows exponentially. The minimum energy requirement were obtained for TSA at a desorbing temperature of 443 K in the three materials, with impurities of 1% H2O for CuBTC, 0.5% H2O for Mg-MOF-74 and 0.02% H2O for 13X, obtaining values of 1.13, 0.55 and 0.58 GJ/tCO2, respectively. Hybrid VTSA processes with impurities content in the feed mixture and CCS specifications achieve energy performances of 0.36 GJ/tCO2 and 0.46 GJ/tCO2 with Mg-MOF-74 and 13X, respectively. Mg-MOF-74 stands up as an attractive material for VTSA processes, presenting higher working capacities, purities and second-law efficiencies, with lower energy consumptions, also showing a better 'buffer' behavior than zeolite 13X when trace impurities are present. This work represents the first quantitative assessment of the process performance of MOFs adsorbents in swing adsorption process for CO2 capture considering impurities effects. Results reinforce the validity of molecular simulations for guiding the optimization of these processes

Armado Óptimo de Secciones de Hormigón Posteso

The amount of passive reinforcement to be provided in the ultimate limit state is computed by means of RSD (Reinforcement Sizing Diagrams) taking into account the presence of active reinforcement, for a particular range of pairs active steel area – active steel eccentricity (Ap – dp) that meet the requirements imposed by the serviceability limit state. The solution that provides the minimum total cost of both active and passive steel is selected.Para un rango de valores de área de armadura activa y de excentricidad que cumplen los requisitos de tensión impuestos por el estado límite de servicio, se evalúa la armadura pasiva necesaria en estado límite último mediante la técnica RSD (Reinforcement Sizing Diagrams) teniendo en cuenta la presencia de la armadura activa. Se selecciona la solución que conduce a un valor mínimo del coste total de armado pasivo y activo

Descripción de dos nuevas especies de pseudoscorpiones cavernícolas de la provincia de Cádiz (Arachnida, Pseudoscorpionida, Chthoniidae, Neobisiidae)

Two new species of cave-dwelling Pseudoscorpionida from Cádiz (South Spain) are described: Chthonius (Ephippiochthonius) aguileraorum sp. n. and Neobisium (Ommatoblothrus) rodrigoi sp. n., and it is compared with the close relatives species.Se describen dos nuevas especies de Pseudoscorpionida cavernícolas procedentes de la provincia de Cádiz (sur de España): Chthonius (Ephippiochthonius) aguileraorum sp. n. y Neobisium (Ommatoblothrus) rodrigoi sp. n., y se comparan con las especias más próximas

An alternative for reducing the layers in the construction of three-phase planar transformers

A modified winding layout for three-phase transformers with PCB windings is proposed in this paper. This modified layout can be used in high current transformers with many PCB layers to simplify the fabrication process. One of the key factors that might increase the cost and complexity in the construction of planar transformers is the number of layers of each PCB winding. This issue becomes even more important in medium-high power three-phase transformers, where the number of PCB layers is higher. In addition to that, the proposed method allows the use of commercial core shapes that are commonly used to design single-phase transformers. This fact makes possible the reduction of cost and flexibility of the design solutions. The proposed solution has been validated and compared using the conventional and the proposed methodologies to design a high power (20 kW) transformer

Anti-Ro52/TRIM21 antibodies are associated with aberrant inflammatory circuits in patients with systemic autoimmune rheumatic diseases

INTRODUCTION: Anti-Ro52/TRIM21 antibodies are markers for several systemic autoimmune rheumatic diseases (SARD). OBJECTIVE: To assess whether anti-Ro52/TRIM21 antibodies are related to abnormalities in inflammatory circuits. METHODS: Cross-sectional study of consecutive outpatients with SARD. Anti-Ro52/TRIM21 antibodies and serum amyloid A protein were measured by ELISA; panels for 18 cytokines and nine chemokines were analyzed on a Luminex reading platform, while high-sensitivity C-reactive protein (hs-CRP) and complement were measured by nephelometry. RESULTS: Among 167 included patients, 143 had systemic lupus erythematosus (SLE), 16 had primary Sjögren's syndrome and eight had systemic sclerosis; 41 (24%) were positive for anti-Ro52/TRIM21 antibodies. Patients with anti-Ro52/TRIM21 antibodies had higher serum levels of IL-2, IL-4, IL-6, GM-CSF, IL-21, IL-22, hs-CRP and chemokines CCL4, CXCL8, CXCL10 and CXCL12, but lower levels of complement C4. Anti-Ro52/TRIM21 antibody titers were positively correlated with IL-2, IL-4, IL-6, IL-10, IL-21, IL-22, CXCL10, and hs-CRP, and negatively with complements C3 and C4. When only SLE patients were included, no association was identified between anti-Ro52/TRIM21 antibodies and disease activity or organ-specific involvement. CONCLUSIONS: Anti-Ro52/TRIM21 antibodies are associated with aberrant cytokine circuits and elevated levels of angiogenic molecules and neutrophil and monocyte chemoattractants, which suggests an active role for these antibodies in SARD.</p

Central star formation and metallicity in CALIFA interacting galaxies

We use optical integral-field spectroscopic (IFS) data from 103 nearby galaxies at different stages of the merging event, from close pairs to merger remnants provided by the CALIFA survey, to study the impact of the interaction in the specific star formation and oxygen abundance on different galactic scales. To disentangle the effect of the interaction and merger from internal processes, we compared our results with a control sample of 80 non-interacting galaxies. We confirm the moderate enhancement (2-3 times) of specific star formation for interacting galaxies in central regions as reported by previous studies; however, the specific star formation is comparable when observed in extended regions. We find that control and interacting star-forming galaxies have similar oxygen abundances in their central regions, when normalized to their stellar masses. Oxygen abundances of these interacting galaxies seem to decrease compared to the control objects at the large aperture sizes measured in effective radius. Although the enhancement in central star formation and lower metallicities for interacting galaxies have been attributed to tidally induced inflows, our results suggest that other processes such as stellar feedback can contribute to the metal enrichment in interacting galaxies.Comment: 9 pages, 9 figures. Accepted for publication in Astronomy & Astrophysic

Molecular gas in NUclei of GAlaxies (NUGA). XI. A complete gravity torque map of NGC4579: new clues on bar evolution

We create a complete gravity torque map of the disk of the LINER/Seyfert 1.9 galaxy NGC4579. We quantify the efficiency of angular momentum transport and search for signatures of secular evolution in the fueling process from r~15kpc down to the inner r~50pc around the Active Galactic Nucleus (AGN). We use both the 1-0 and 2-1 line maps of CO obtained with the Plateau de Bure Interferometer (PdBI) as part of the NUclei of Galaxies-(NUGA)-project. We derive the stellar potential from a NIR (K band) wide field image of the galaxy. The K-band image, which reveals a stellar bar, together with a high resolution HI map of NGC4579 obtained with the Very Large Array (VLA), allow us to extend the gravity torque analysis to the outer disk. The bulk of the gas response traced by the CO PdBI maps follows the expected gas flow pattern induced by the bar potential in the presence of two Inner Lindblad Resonances (ILR). We also detect an oval distortion in the inner r~200pc of the K-band image. The oval is not aligned with the large-scale bar, a signature of dynamical decoupling. The morphology of the outer disk suggests that the neutral gas is currently piling up in a pseudo-ring formed by two winding spiral arms that are morphologically decoupled from the bar structure. In the outer disk, the decoupling of the spiral allows the gas to efficiently produce net gas inflow on intermediate scales. The corotation barrier seems to be overcome due to secular evolution processes. The gas in the inner disk is efficiently funneled by gravity torques down to r~300pc. Closer to the AGN, the two m=2 modes (bar and oval) act in concert to produce net gas inflow down to r~50pc, providing a clear smoking gun evidence of fueling with associated short dynamical time-scales.Comment: Submitted for publication in A&A. 21 pages, 21 figure

The AMIGA sample of isolated galaxies. IV. A catalogue of neighbours around isolated galaxies

Studies of the effects of environment on galaxy properties and evolution require well defined control samples. Such isolated galaxy samples have up to now been small or poorly defined. The AMIGA project (Analysis of the interstellar Medium of Isolated GAlaxies) represents an attempt to define a statistically useful sample of the most isolated galaxies in the local (z < 0.05) Universe. A suitable large sample for the AMIGA project already exists, the Catalogue of Isolated Galaxies (CIG, Karachentseva 1973; 1050 galaxies), and we use this sample as a starting point to refine and perform a better quantification of its isolation properties. Digitised POSS-I E images were analysed out to a minimum projected radius R > 0.5 Mpc around 950 CIG galaxies (those within Vr = 1500 km s-1 were excluded). We identified all galaxy candidates in each field brighter than B = 17.5 with a high degree of confidence using the LMORPHO software. We generated a catalogue of approximately 54 000 potential neighbours (redshifts exist for 30% of this sample). Six hundred sixty-six galaxies pass and two hundred eighty-four fail the original CIG isolation criterion. The available redshift data confirm that our catalogue involves a largely background population rather than physically associated neighbours. We find that the exclusion of neighbours within a factor of four in size around each CIG galaxy, employed in the original isolation criterion, corresponds to Delta Vr ~ 18000 km s-1 indicating that it was a conservative limit. Galaxies in the CIG have been found to show different degrees of isolation. We conclude that a quantitative measure of this is mandatory. It will be the subject of future work based on the catalogue of neighbours obtained here.Comment: Accepted by A&A, 10 pages, 8 figures, 4 table