Advances in Atomic Data for Neutron-Capture Elements

Neutron(n)-capture elements (atomic number Z>30), which can be produced in planetary nebula (PN) progenitor stars via s-process nucleosynthesis, have been detected in nearly 100 PNe. This demonstrates that nebular spectroscopy is a potentially powerful tool for studying the production and chemical evolution of trans-iron elements. However, significant challenges must be addressed before this goal can be achieved. One of the most substantial hurdles is the lack of atomic data for n-capture elements, particularly that needed to solve for their ionization equilibrium (and hence to convert ionic abundances to elemental abundances). To address this need, we have computed photoionization cross sections and radiative and dielectronic recombination rate coefficients for the first six ions of Se and Kr. The calculations were benchmarked against experimental photoionization cross section measurements. In addition, we computed charge transfer (CT) rate coefficients for ions of six n-capture elements. These efforts will enable the accurate determination of nebular Se and Kr abundances, allowing robust investigations of s-process enrichments in PNe.Comment: To be published in IAU Symp. 283: Planetary Nebulae, an Eye to the Future; 2 page

Adaptive comfort and climate-sensitive architecture: how occupants feel in their homes?

Postprint (published version

Unveiling the Temperature Influence on the Sorptive Behaviour of ZIF-8 Composite Materials Impregnated with [Cn MIM][B(CN)4 ] Ionic Liquids

LA/P/0008/2020 PTDC/CTM-CTM/ 30326/2017Composite sorbent materials (IL@MOF) with a metal-organic framework (MOF) ZIF-8 and [B(CN)4 ]−-based ionic liquids (ILs) were produced for the first time. Characterization results indicate the successful IL impregnation and conservation of the ZIF-8 crystalline structure and morphology. The data collected from the nitrogen (N2 ) physisorption at 77 K suggest that these IL@ZIF-8 materials are nonporous as their textural properties, such as BET specific surface area and total pore volume, are negligible. However, CO2, CH4, and N2 adsorption/desorption measurements in the IL@ZIF-8 composites at 303 and 273 K contradict the N2 data at 77 K, given that the obtained isotherms are Type I, typical of (micro)porous materials. Their gas adsorption capacity and ultramicroporous volume are in the same order of magnitude as the pristine microporous ZIF-8. The case study [C6 MIM][B(CN)4 ] IL revealed a high affinity to both CO2 and CH4 . This compromised the selectivity performance of its respective composite when compared with pristine ZIF-8. This work highlights the importance of accurate experimental gas adsorption/desorption equilibrium measurements to characterize the adsorption uptake and the porous nature of adsorbent materials.publishersversionpublishe

Hybrid membrane/PSA processes for CO2/N-2 separation

New integrated schemes combining membrane permeation and pressure swing adsorption (PSA) have been developed for gas separation. By using the membrane as a pre-bulk separation unit and coupling it to the intrinsically dynamic periodic operation of the PSA, the separation performance of the hybrid scheme is enhanced with respect to that of die two stand-alone units. Instead of constant-composition regular feed, the PSA is fed with a mixture which is progressively enriched in the more adsorbed component during the pressurization and high-pressure adsorption steps of the cycle. This results in sharper concentration fronts. The hybrid scheme detailed here has been applied successfully to the bulk separation of an 30:70 mol% CO2/N-2 mixture over activated carbon. Process performance is reported in terms of product recovery and purity at cyclic steady state. Numerical simulations were validated by experimental work on a composite membrane and a laboratory-scale PSA unit. For the examples studied, product purity and recovery for the hybrid process were increased by 23% and 58% for CO2, and by 14% and 5% for N-2, compared to an equivalent stand-alone PSA.publishersversionpublishe

Carbon Materials Derived from Cyano-Based IL@ZIF-8 Composites for CO2 Sorption Separation Systems

Additionally, this work was partially supported by the Asso- ciate Laboratory for Green Chemistry, LAQV, which is funded by national funds from FCT/MCTES (LA/P/00 08/2020) .The sorption capacity and selectivity of pre- and post-carbonized cyano-based metal-organic framework (MOF) composite materials (cyano-based IL@ZIF-8) were investigated for the first time. The influence of the ionic liquid (IL) loading and number of cyano groups in the IL anion on a materials gas sorption separation performance was studied. Sorption-desorption equilibrium isotherms of CO2, CH4, and N2 were measured at 303 K in the ZIF-8, cyano-based IL@ZIF-8 composites and their derived carbon materials. The IL loading did not significantly affect the gas uptake of the carbon materials, while for the composites its main contribution was on the increase of the selectivity. The number of cyano groups in the anion played a key role in the sorption capacity and selectivity performance as it directly affects the N content and textural properties. The carbon material obtained from ZIF-8 (C_ZIF-8) precursor showed the best sorption capacity for all gases, just being surpassed by the C_15%[C6MIM][B(CN)4]@ZIF-8 carbon up to 1 bar. In terms of selectivity performance, carbons based on [C6MIM][B(CN)4]@ZIF-8 composites revealed to be equally or more selective than C_ZIF-8, increasing up to 65% between 0 and 1 bar depending on the mixture. The composites produced and their respective carbons demonstrated a promising application as sorbents for post-combustion CO2 separation systems.publishersversionpublishe

Óleo de soja e gordura animal na alimentação de eqüinos.

O objetivo deste trabalho foi estudar os efeitos da gordura animal e do óleo de soja como fontes de energia em potras da raça Árabe e Cruza/Árabe. Forarm utilizados 21 animais, com peso médio inicial de 228 kg e 13 meses de idade media, distribuidos em três tratamentos

Estudos da patogenicidade do circovirus suíno tipo 2 (PCV2) em suínos e do papel do macho suíno na disseminação viral dentro do plantel.

Projeto/Plano de Ação: 03.03.230.01

Congenital defects of the middle ear-uncommon cause of pediatric hearing loss

INTRODUCTION: In children, hypoacusis, or conductive hearing loss, is usually acquired; otitis media with effusion is the most common etiology. However, in some cases this condition is congenital, ranging from deformities of the external and middle ear to isolated ossicular chain malformations. The non-ossicular anomalies of the middle ear, for instance, persistent stapedial artery and anomaly of the facial nerve, are uncommon but may accompany the ossicular defects. OBJECTIVE: This study aimed to describe the clinical presentation, diagnostic tests, and therapeutic options of congenital malformations of the middle ear. METHODS: This was a retrospective study of cases followed in otolaryngologic consultations since 2007 with the diagnosis of congenital malformation of the middle ear according to the Teunissen and Cremers classification. A review of the literature regarding the congenital malformation of the middle ear and its treatment is presented. CONCLUSION: Middle ear malformations are rarely responsible for conductive hearing loss in children. As a result, there is often a late diagnosis and treatment of these anomalies, which can lead to delays in the development of language and learnin