Optimization of the catalytic layer for alkaline fuel cells based on fumatech membranes and ionomer

Polymer electrolyte fuel cells with alkaline anion exchange membranes (AAEMs) have gained increasing attention because of the faster reaction kinetics associated with the alkaline environment compared to acidic media. While the development of anion exchange polymer membranes is increasing, the catalytic layer structure and composition of electrodes is of paramount importance to maximize fuel cell performance. In this work, we examine the preparation procedures for electrodes by catalyst-coated substrate to be used with a well-known commercial AAEM, Fumasep® FAA-3, and a commercial ionomer of the same nature (Fumion), both from Fumatech GmbH. The anion exchange procedure, the ionomer concentration in the catalytic layer and also the effect of membrane thickness, are investigated as they are very relevant parameters conditioning the cell behavior. The best power density was achieved upon ion exchange of the ionomer by submerging the electrodes in KCl (isopropyl alcohol/water solution) for at least one hour, two exchange steps, followed by treatment in KOH for 30 min. The optimum ionomer (Fumion) concentration was found to be close to 50 wt%, with a relatively narrow interval of functioning ionomer percentages. These results provide a practical guide for electrode preparation in AAEM-based fuel cell research

Usefulness of the CAT, LCOPD, EQ-5D and COPDSS Scales in Understanding the Impact of Lung Disease in Patients with Alpha-1 Antitrypsin Deficiency

Alpha-1-antitrypsin defi ciency (AATD) is an inherited disorder responsible for early onset emphysema associated with a signifi cant impairment of healthrelated quality of life (HRQoL). Our aim was to assess the usefulness of different instruments to evaluate the HRQoL in patients with AATD compared to non-AATD COPD. Observational, cross-sectional study in which all patients fi lled out a series of questionnaires: the COPD severity score (COPDSS), the EuroQoL 5-Dimensions (EQ-5D), the Living with COPD (LCOPD) and the COPD Assessment Test (CAT). A total of 96 patients were included, 35 with AATD (mean age 56.5 yrs, 57.1% male and mean FEV1(%) 48.7% and 61 non-AATD COPD (70.3 yrs, 80.3% men and FEV1(%) 47%. The questionnaire scores were similar, with a tendency towards worse scores in AATD for the EQ-5D (VAS) (64.8 (20.2) vs. 71.6 (17.1); p = 0.08). The correlations between the different scores and FEV1(%) were signifi cant in both groups for COPDSS and LCOPD, but not for CAT and EQ-5D. In general, the correlations of scores with FEV1(%) were stronger for AATD compared with non-AATD COPD patients: COPDSS r = –0.570, p < 0.01 for AATD and r = –0.260, p < 0.05 for COPD; LCOPD r = –0.502, p < 0.001 for AATD and r = –0.304, p < 0.05 for non-AATD COPD. Patients with AATD have a similar degree of HRQoL impairment as older subjects with non-AATD COPD and showed a stronger correlation between HRQoL measurements and lung function impairment compared with non-AATD COPD. This may be related to the characteristics of the disease in these patients who are usually younger, with less co-morbidity and lower smoking consumption

Distribution and ecology of recent ostracods from the Villafáfila lakes (Zamora, Spain)

En este trabajo se estudian las asociaciones de ostrácodos que habitan en las Lagunas de Villafáfila (Zamora) y que han permitido caracterizar los diversos subambientes que se desarrollan en estos humedales. Así, se define un primer subambiente de cuerpos temporales de agua dulce con cierta hidrodinámica donde predomina Leucocythere aff. mirabilis. La abundancia de Ilyocypris bradyi caracteriza un segundo subambiente de margen lacustre somero al que llegan arroyos o pequeños riachuelos de agua corriente. El tercer subambiente consiste en aguas semipermanentes con poca corriente y moderada salinidad, definido por la abundancia de Limnocythere inopinata . Finalmente, se ha identificado un cuarto subambiente de humedal efímero con aguas con poca corriente y elevada salinidad en el que predomina Sarscypridopsis aculeata . Queda puesto de manifiesto con este trabajo que los principales factores ecológicos que condicionan la distribución de los ostrácodos en las Lagunas de Villafáfila son la hidrodinámica, el hidroperiodo y la salinidad del agua. Estos datos, además, servirán como comparativa o modelo actual para futuros trabajos de reconstrucción paleoambiental que se vayan a realizar en medios límnicos neógenos de la Península Ibérica, empleando las asociaciones de ostrácodosIn this work, the ostracod assemblages that inhabit in the Villafáfila lakes have been studied, allowing the characterization of several subenvironments developed in these wetlands. Thus, a first subenvironment of temporary fresh water bodies with some hydrodynamism where Leucocythere aff. mirabilis is dominant has been identified. The abundance of Ilyocypris bradyi characterized a second subenvironment of streams and small rivers of flowing waters that run into shallow lacustrine margins. The third subenvironment consists in semipermanent water bodies with low current and moderate salinity defined by the abundance of Limnocythere inopinata. Finally, a fourth subenvironment of ephemeral wetlands with slow currents and high salinity has been defined by the predominance of Sarscypridopsis aculeata . This work highlights that hydrodynamic, hydroperiod and water salinity are the main ecological factors that control the ostracods distribution along the Villafáfila lakes. Besides, these data will be used as comparison or recent model for future works focused on the neogene palaeoenvironmental reconstruction of other limnic settlements of the Iberian Peninsula using ostracod assemblage

Solvothermal synthesis of lanthanide-functionalized graphene oxide nanocomposites

We propose a facile approach to the preparation of graphene oxide (GO) composites with lanthanide (Ln) oxide/hydroxide nanoparticles (Ln = La, Eu, Gd, Tb) under relatively mild conditions by two different procedures of solvothermal synthesis. The mechanism of GO-Ln nanocomposite formation is thought to involve the initial coordination of Ln3+ ions to the oxygen-containing groups of GO as nucleation sites, followed by f Ln2O3 and Ln(OH)3 nanoparticle growth. The nanocomposites obtained preserve the intrinsic planar honeycomb-like structures of graphene as proven by the typical G and D bands in the Raman spectra. Fourier-transform infrared and X-ray photoelectron spectroscopy confirm the interaction between oxygen-containing groups of GO and Ln ions. The size and distribution of Ln oxide/hydroxide nanoparticles on GO sheets, estimated from scanning and transmission electron microscopy images, vary broadly for the different lanthanides. The size can span from sub-nm dimensions for Eu oxide to more than 10 μm for Eu hydroxide nanoparticles. The most homogeneous distribution of Ln oxide/hydroxide nanoparticles was found in La-containing composites. Thermogravimetric analysis demonstrated that all the GO-Ln nanocomposites are thermally less stable, by up to 30 °C than pristine GO.</p

MARKETING DE INFLUENCIADORES Y SU EFECTO EN LA INTENCIÓN DE COMPRA DE LOS CONSUMIDORES DE PRENDAS ECOLÓGICAS

El marketing de influencers se está utilizando rápidamente como plataforma para actividades promocionales. La sostenibilidad ha comenzado a tener un impacto en el mercado peruano. El brusco aumento de la concienciación es una de las principales causas de este incremento. Este estudio se centra en el análisis de las conexiones entre las actitudes, las creencias y las intenciones de los consumidores de comprar prendas ecológicas promocionadas a través del marketing de influenciadores, la credibilidad de los influencers, la influencia social y la eficacia percibida por los consumidores. Los datos de la encuesta se obtuvieron de 279 personas residentes en la ciudad de Trujillo y Chiclayo en el Perú, mediante un cuestionario. El análisis de los datos se realizó con el software SmartPLS 3.3.0. Según los datos, una actitud favorable, la credibilidad del influenciador, la influencia social y la eficacia percibida por el consumidor conducen a la intención de compra. Esta investigación amplía los elementos que influyen en la intención de compra de los consumidores de prendas ecológicas con referencia al marketing de influenciadores

Nitrogen-carbon graphite-like semiconductor synthesized from uric acid

A new carbon-nitrogen organic semiconductor has been synthesized by pyrolysis of uric acid. This layered carbon-nitrogen material contains imidazole-, pyridine (naphthyridine)- and graphitic-like nitrogen, as evinced by infrared and X-ray photoelectron spectroscopies. Quantum chemistry calculations support that it would consist of a 2D polymeric material held together by hydrogen bonds. Layers are stacked with an interplanar distance between 3.30 and 3.36 Å, as in graphite and coke. Terahertz spectroscopy shows a behavior similar to that of amorphous carbons, such as coke, with non-interacting layers. This material features substantial differences from polymeric carbon nitride, with some characteristics closer to those of nitrogen-doped graphene, in spite of its higher nitrogen content. The direct optical band gap, dependent on the polycondensation temperature, ranges from 2.10 to 2.32 eV. Although in general the degree of crystallinity is low, in the material synthesized at 600 °C some spots with a certain degree of crystallinity can be found