On the signature of z∼0.6z\sim 0.6 superclusters and voids in the Integrated Sachs-Wolfe effect

Through a large ensemble of Gaussian realisations and a suite of large-volume N-body simulations, we show that in a standard LCDM scenario, supervoids and superclusters in the redshift range $z\in[0.4,0.7]$ should leave a {\em small} signature on the ISW effect of the order $\sim 2 \mu$K. We perform aperture photometry on WMAP data, centred on such superstructures identified from SDSS LRGs, and find amplitudes at the level of 8 -- 11$\mu$K -- thus confirming the earlier work of Granett et al 2008. If we focus on apertures of the size \sim3.6\degr, then our realisations indicate that LCDM is discrepant at the level of $\sim4 \sigma$. If we combine all aperture scales considered, ranging from 1\degr--20\degr, then the discrepancy becomes $\sim2\sigma$, and it further lowers to $\sim 0.6 \sigma$ if only 30 superstructures are considered in the analysis (being compatible with no ISW signatures at $1.3\sigma$ in this case). Full-sky ISW maps generated from our N-body simulations show that this discrepancy cannot be alleviated by appealing to Rees-Sciama mechanisms, since their impact on the scales probed by our filters is negligible. We perform a series of tests on the WMAP data for systematics. We check for foreground contaminants and show that the signal does not display the correct dependence on the aperture size expected for a residual foreground tracing the density field. The signal also proves robust against rotation tests of the CMB maps, and seems to be spatially associated to the angular positions of the supervoids and superclusters. We explore whether the signal can be explained by the presence of primordial non-Gaussianities of the local type. We show that for models with \FNL=\pm100, whilst there is a change in the pattern of temperature anisotropies, all amplitude shifts are well below $<1\mu$K.Comment: 14 pages, 9 figures, matches accepted version in MNRA

Theoretical study of two-photon circular dichroism on molecular structures simulating aromatic amino acid residues in proteins with secondary structures

Herein, we report on the calculation and the comparative analysis of the theoretical two-photon circular dichroism (TPCD) spectra of L-histidine (His), L-phenylalanine (Phe), and L-tyrosine (Tyr) simulating residues in proteins with secondary structures (alpha-helix, beta-strand and random coil), down to the far-UV region (FUV). This work exposes unique signatures in the FUV for each conformer in each configuration. The outcomes of this research show how FUV-TPCD can be used to study peptide and protein structures in a region never evaluated before but packed with important structural information

Fuzzy Control Strategy for an Anaerobic Wastewater Treatment Process

In this paper, a fuzzy control strategy (FCS) for an anaerobic wastewater treatment process is proposed in order to reject large disturbances on input substrate allowing a high methane production. This strategy is composed of: i) a state observer, which is based on a principal components analysis (PCA) and Takagi-Sugeno (TS) algorithm; it is designed to estimate variables hard to measure: biomass and substrate, ii) proportional-integral (PI) controllers based on a combination of the L/A(logarithm/antilogarithm) and fuzzy approaches; these controllers have variable gains and are designed to regulate bicarbonate in the reactor by two control actions: a base supplying (binc) and dilution rate (D) changes, iii) a TS supervisor which detects the process state, selects and applies the most adequate control action, allowing a smooth switching between open loop and closed loop. Applicability of the proposed structure in a completely stirred tank reactor (CSTR) is illustrated via simulations. The obtained results show that the process works in open loop in presence of small disturbances. For large disturbances, the supervisor allows the control actions to be applied avoiding washout; after that, the process returns to open loop operation. In general, the FCS improves the performances of the anaerobic process and is feasible for application in real processes, since the control scheme shows a good compromise between efficiency and complexity

Density functional theory study of the zeolite-mediated tautomerization of phenol and catechol

Because the structure of lignin consists mostly of inter-linked phenolic monomers, its conversion into more valuable chemicals may benefit from isomerization processes that alter the electronic structure of the aromatic rings. The tautomerization of phenolic-type compounds changes the hybridization from sp2 to sp3 of the carbon atom at the ortho position, which disables the aromaticity and facilitates the subsequent hydrogenation process. Here, we have performed a Density Functional Theory study of the tautomerization of phenol and catechol at the external surface of zeolite MFI. The tautomerization starts with the adsorption of the molecule on three-coordinated Lewis acid sites, followed by the dissociation of the phenolic hydroxyl group, with the transfer of the proton to the zeolite framework. The rotation of the deprotonated molecule enables a more favourable orientation for the back-transfer of the proton to the carbon atom at the ortho position. The energy barriers of the process are smaller than 55 kJ/mol, suggesting that this transformation is easily accessible under standard reaction conditions

Editorial: Vascular dysfunction beyond pathological pregnancies. An international effort addressed to fill the gaps in Latin America, Volume II

Q1Q1Mujeres en estado de embarazoRecent evidence suggests that vascular changes associated with pregnancy complications, such as preeclampsia; gestational diabetes; growth restriction; autoimmune diseases; among others, affect the function of the maternal and offspring vascular systems after delivery and may be extended until adult life (Giachini et al., 2017; Dayan et al., 2018; Honigberg et al., 2019). Furthermore, since the vascular system contributes to systemic homeostasis, defective development or function of blood vessels predisposes both mother and infant to future risk for chronic disease (Davis et al., 2012; Phipps et al., 2019).https://orcid.org/0000-0002-6804-0979Revista Internacional - IndexadaA1N

DFT modeling of the adsorption of trimethylphosphine oxide at the internal and external surfaces of zeolite MFI

The characterization of the acidity of zeolites allows a direct correlation with their catalytic activity. To this end, probe molecules are utilized to obtain a ranking of acid strengths. Trimethylphosphine oxide (TMPO) is a widely used probe molecule, which allows the sensing of solid acids by using 31P NMR. We have performed calculations based on the density functional theory to investigate the Brønsted acid (BA) sites in zeolite MFI by adsorbing TMPO as a probe molecule. We have considered the substitution of silicon at the T2 site by aluminum, both at the internal cavity and at the external surface. The different acid strengths observed in the zeolite MFI when probed by TMPO (very strong, strong, and weak) may depend on the basicity of the centers sharing the acid proton. If the proton lies between the TMPO and one of the framework oxygen atoms binding the Al, the acidity is strong. When the framework oxygen atom is not directly binding the Al, it is less basic and a shortening of the TMPO–H distance is observed, causing an acid response of very strong. Finally, if two TMPO molecules share the proton, the TMPO–H distance elongates, rendering a weak acid character

A Global Kinetic Mechanism for the Prediction of Hg Oxidation by a Chlorine Species

This paper presents a global kinetic model developed from laboratory test results. The model consists of five global reactions - two reversible and three irreversible. The reaction constants for the Arrhenius expression formulation were determined from a set of 35 experiments involving a variety of flue gas compositions that include bulk gases (N2, CO2 and O2.) and trace gases (NO, SO2, Hg, Cl2); at a range of temperatures (from 540 °C to 166 °C) and a variety of residence times (between 2.7 and 3.3 seconds). The values obtained for the reaction constants were further used to predict experimental data from eleven published mercury data sources. The predicted values corresponded very well compared to the observed published data.Key words:  Kinetics model; Mercury emission; Homogeneous mercury oxidatio

A density functional theory study of the structure of pure-silica and aluminium-substituted MFI nanosheets

The layered MFI zeolite allows a straightforward hierarchization of the pore system which accelerates mass transfer and increases its lifetime as a catalyst. Here, we present a theoretical study of the structural features of the pure-silica and aluminium-substituted MFI nanosheets. We have analysed the effects of aluminium substitution on the vibrational properties of silanols as well as the features of protons as counter-ions. The formation of the two-dimensional system did not lead to appreciable distortions within the framework. Moreover, the effects on the structure due to the aluminium dopants were the same in both the bulk and the slab. The principal differences were related to the silanol groups that form hydrogen-bonds with neighbouring aluminium-substituted silanols, whereas intra-framework hydrogen-bonds increase the stability of aluminium-substituted silanols toward dehydration. Thus, we have complemented previous experimental and theoretical studies, showing the lamellar MFI zeolite to be a very stable material of high crystallinity regardless of its very thin structure