52 research outputs found
Atomically dispersed Pt-N-4 sites as efficient and selective electrocatalysts for the chlorine evolution reaction
Chlorine evolution reaction (CER) is a critical anode reaction in chlor-alkali electrolysis. Although precious metal-based mixed metal oxides (MMOs) have been widely used as CER catalysts, they suffer from the concomitant generation of oxygen during the CER. Herein, we demonstrate that atomically dispersed Pt-N-4 sites doped on a carbon nanotube (Pt-1/CNT) can catalyse the CER with excellent activity and selectivity. The Pt-1/CNT catalyst shows superior CER activity to a Pt nanoparticle-based catalyst and a commercial Ru/Ir-based MMO catalyst. Notably, Pt-1/CNT exhibits near 100% CER selectivity even in acidic media, with low Cl- concentrations (0.1M), as well as in neutral media, whereas the MMO catalyst shows substantially lower CER selectivity. In situ electrochemical X-ray absorption spectroscopy reveals the direct adsorption of Cl- on Pt-N-4 sites during the CER. Density functional theory calculations suggest the PtN4C12 site as the most plausible active site structure for the CER
A semi-automated algorithm for hypothalamus volumetry in 3 Tesla magnetic resonance images
The hypothalamus, a small diencephalic gray matter structure, is part of the limbic system. Volumetric changes of this structure occur in psychiatric diseases, therefore there is increasing interest in precise volumetry. Based on our detailed volumetry algorithm for 7 Tesla magnetic resonance imaging (MRI), we developed a method for 3 Tesla MRI, adopting anatomical landmarks and work in triplanar view. We overlaid T1-weighted MR images with gray matter-tissue probability maps to combine anatomical information with tissue class segmentation. Then, we outlined regions of interest (ROIs) that covered potential hypothalamus voxels. Within these ROIs, seed growing technique helped define the hypothalamic volume using gray matter probabilities from the tissue probability maps. This yielded a semi-automated method with short processing times of 20–40 min per hypothalamus. In the MRIs of ten subjects, reliabilities were determined as intraclass correlations (ICC) and volume overlaps in percent. Three raters achieved very good intra-rater reliabilities (ICC 0.82–0.97) and good inter-rater reliabilities (ICC 0.78 and 0.82). Overlaps of intra- and inter-rater runs were very good (≥ 89.7%). We present a fast, semi-automated method for in vivo hypothalamus volumetry in 3 Tesla MRI
Premium Private Labels and PDO/PGI Products: Effects on Customer Loyalty
The paper analyses the role that Premium Private Labels (PPLs) exerts on customer loyalty to the retailer, intended as behavioral and attitudinal. Specifically, the study investigates the mediating role of customer loyalty to the PPL (PPLL), highlighting its main antecedents. The paper contributes to the literature on store brands and customer loyalty in a twofold way. Firstly, it responds to the call for more research on customer loyalty to the retailer as a brand, a topic requiring more empirical evidence compared to store loyalty. Secondly, as many PPLs consist in local products labelled with a PDO/PGI brand too as vehicle to increase the per-ceived value of this store brand tier, the study would investigate the impact of this brand guarantee on PPLs proneness.
A survey was performed on a sample of retail customers. All the postulated hypotheses were confirmed applying SEM. Willingness to pay an extra price for a PPL product (PPL WP) resulted as the main antecedent of PPLL, followed by PPL perceived quality (PPLQ) and then by the guarantee that the PDO/PGI label offers to PPL buyers (TPG). Residual the effect of PPL Uniqueness (PPLU). Significant and positive resulted the effect of PPLL on both attitudinal and behavioral loyalty to the retailer. Indirect effects were confirmed too
Dynamic surface self-reconstruction is the key of highly active perovskite nano-electrocatalysts for water splitting
Self-assembly of noble metal monolayers on transition metal carbide nanoparticle catalysts
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