Performance, structure, and mechanism of CeO₂ in HCl oxidation to Cl₂

Experimental and theoretical studies reveal performance descriptors and provide molecular-level understanding of HCl oxidation over CeO2. Steady-state kinetics and characterization indicate that CeO2 attains a significant activity level, which is associated with the presence of oxygen vacancies. Calcination of CeO2 at 1173 K prior to reaction maximizes both the number of vacancies and the structural stability of the catalyst. X-ray diffraction and electron microscopy of samples exposed to reaction feeds with different O2/HCl ratios provide evidence that CeO2 does not suffer from bulk chlorination in O2-rich feeds (O2/HCl ≥ 0.75), while it does form chlorinated phases in stoichiometric or sub-stoichiometric feeds (O2/HCl ≤ 0.25). Quantitative analysis of the chlorine uptake by thermogravimetry and X-ray photoelectron spectroscopy indicates that chlorination under O2-rich conditions is limited to few surface and sub-surface layers of CeO2 particles, in line with the high energy computed for the transfer of Cl from surface to sub-surface positions. Exposure of chlorinated samples to a Deacon mixture with excess oxygen rapidly restores the original activity levels, highlighting the dynamic response of CeO2 outermost layers to feeds of different composition. Density functional theory simulations reveal that Cl activation from vacancy positions to surface Ce atoms is the most energy-demanding step, although chorine-oxygen competition for the available active sites may render re-oxidation as the rate-determining step. The substantial and remarkably stable Cl2 production and the lower of CeO2 make it an attractive alternative to RuO2 for catalytic chlorine recycling in industry

Collective Impact Partnership and Backbone Organizations as Enablers of Children’s Well-Being

In this article, the question of partnership is approached from a perspective centred around the creation of a common agenda based on trust and from the children´s point of view. Partnership and collaboration have traditionally been viewed as mechanisms to create bridges between organisations and institutions from the private, public and non-governmental sectors in order to enhance funder collaboratives, public-private partnerships, multi-stakeholder initiatives, social sector networks and collective impact initiatives. It was not however until Kania and Kramer´s (2011) seminal work on collective impact when this subject came to be viewed as a developmental process aiming at the creation of a common agenda and mutually agreed activities and consisting of five integral parts: a common agenda, shared measurement systems, mutually reinforcing activities, continuous communication and backbone support organisations. This article, based on a systematic review of the topic, maintains that partnership – approached from the point of view of children and through the lens of collective impact – constitutes a crucial mechanism in the creation of safe and comprehensive wellbeing for children. Thus, this article – using Kania and Kramer´s (2011) definition of collective impact and focusing on the structure of partnerships and the nature of trust in organisations as the prerequisite for partnership – advocates the importance of the UN SDG17 principle as the bringer of inclusive society built upon principles and values, a shared vision, and shared goals that place people at the centre of human endeavour.© Springer Nature Switzerland AG 2020. This is a post-peer-review, pre-copyedit version of an article published in Partnerships for the Goals. Encyclopedia of the UN Sustainable Development Goals. The final authenticated version is available online at: http://dx.doi.org/10.1007/978-3-319-71067-9_111-1.fi=vertaisarvioitu|en=peerReviewed

Cellule "Base De Données"

Cellule "Base De Données

Mass development of marine benthic Sarcinochrysidales (Chrysophyceae <i>s.l.</i>) in Corsica

A mass development of benthic Sarcinochrysidales (Chrysophyceae s.l.), especially of Chvysoreinhardia giraudii comb, nov. (basionym: Tetraspora giraudii) and Nematochrysopsis marina comb. nov. (basionym: Tribonema marinum), is reported from the Corsican coast. Morphology, habitat and seasonal development of these taxa as well as of the less regularly observed Chrysonephos lewisii and of some Chrysophyceae s.l. associated with Chrysoveinhardia giraudii sheaths are presented

Cystic dilation of the distal end of the nasolacrimal duct: underrated cause of epiphora in adults and its endoscopic treatment.

Epiphora is a frequent reason for ophthalmologic consultation. Among the multiple causes, obstructions of the lacrimal excretory system are common. Sacal and postsacal obstructions are much more frequent than presacal obstructions. Obstruction at the level of the Hasner's valve is rare and likely underestimated. The authors report the clinical history and the imaging of 3 patients with a cystic dilation of the distal end of the nasolacrimal duct (NLD). These patients were easily managed by an ENT surgeon. In one case, the surgery consisted of an endonasal DCR where in the 2 other cases, a marsupialisation of the cystic expansion of the nasolacrimal duct was successfully performed with the micro- debrider. The authors review the world literature on this specific topic. They conclude that a coronal sinus CT scan and an inferior meatus endoscopy should be included in the ophthalmologic work-up performed in all cases of low obstruction of the lacrimal system. When there is a dilation of the distal end of the NLD the marsupialisation of the cystic expansion in the inferior meatus is the option of treatment instead of performing a DCR. ENTs must play a role in the assessment and treatment of low obstructions of the lacrimal excretory system

Eurosceptic Challenger Parties and Political Opposition in European Union Politics: Part of the Problem or Part of the Solution?

Despite extensive research on Eurosceptic challenger parties, our knowledge of their influence on political opposition has so far been sparse. In this article we make an in-depth assessment of parliamentary EU opposition, based on 4,264 statements made by national parliamentarians in the European Affairs Committees (EACs) of Denmark and Sweden. Our analysis shows that the presence of Eurosceptic challenger parties in the national parliamentary arena impacts patterns and practices of EU opposition significantly. A greater presence of ‘hard’ Eurosceptic parties in parliament is associated with more opposition in EU politics. These parties deliver a vast majority of the polity-oriented opposition towards the EU and present more policy alter- natives than mainstream parties. The findings presented have implications for our understand- ing of national parliamentary EU opposition as well as for the assessment of the impact of Eurosceptic challenger parties on the process of European integration.