40 research outputs found
Soft Loans as an Instrument of Development Finance: A Comparative Assessment and Options for the Future
Within the framework of the Post-2015 Development Agenda, discussions on Financing for Development and the future of Official Development Assistance (ODA) have intensified. Amongst the instruments under review are soft loans. Though originally conceived as export promotion tools, development objectives have recently become more prominent in soft loan policies. Albeit regulated through the Arrangement on Officially Supported Export Credits, soft loans claim a place amongst the instruments of development policy. By means of comparative case study analysis, this paper examines the relevance of soft loans as an instrument of development policy. We discuss three characteristics of soft loan financing: (i) the institutional heterogeneity of programmes between countries, (ii) the hybrid nature of the instruments between export promotion and development objectives, and (iii) the underlying notions of development. Upon that basis, scenarios for the future use of soft loans as an instrument of development finance are presented
Surface Functionalization of Grown-on-Tip ZnO Nanopyramids: From Fabrication to Light-Triggered Applications
We report on a combined
chemical vapor deposition (CVD)/radio frequency
(RF) sputtering synthetic strategy for the controlled surface modification
of ZnO nanostructures by Ti-containing species. Specifically, the
proposed approach consists in the CVD of grown-on-tip ZnO nanopyramids,
followed by titanium RF sputtering under mild conditions. The results
obtained by a thorough characterization demonstrate the successful
ZnO surface functionalization with dispersed Ti-containing species
in low amounts. This phenomenon, in turn, yields a remarkable enhancement
of photoactivated superhydrophilic behavior, self-cleaning ability,
and photocatalytic performances in comparison to bare ZnO. The reasons
accounting for such an improvement are unravelled by a multitechnique
analysis, elucidating the interplay between material chemico-physical
properties and the corresponding functional behavior. Overall, the
proposed strategy stands as an amenable tool for the mastering of
semiconductor-based functional nanoarchitectures through <i>ad
hoc</i> engineering of the system surface
Human egress modelling in fire situations
Ce travail, mené conjointement entre CNPP et le Laboratoire d’Énergétique et de Mécanique Théorique et Appliquée, est consacré à la mise en place d’un modèle d’évacuation de personnes, dans l’optique d’une application en Ingénierie de Sécurité Incendie. Le modèle de cheminement de personnes développé dans ce manuscrit est un modèle physique reposant sur une équation de conservation de la densité de personnes. Il est basé sur des hypothèses simples et réalistes résultant de l’observation de mouvements de foule, et utilise une vision macroscopique des personnes caractérisées par une densité moyenne. Ce modèle est mis en œuvre sur des cas de vérification et de comparaison issus de la littérature. Des expériences d’évacuation sont réalisées à échelle réelle afin de récolter des données quantitatives sur le mouvement des personnes et de valider de façon pertinente le modèle de cheminement de personnes. En outre, une stratégie est proposée afin d’intégrer dans la modélisation les contraintes thermiques et optiques liées au feu ainsi que leur impact sur le processus d’évacuation. Enfin, des simulations d’évacuation intégrant les effets du feu sont effectuées sur une configuration à grande échelleThis work was conducted as a collaboration between CNPP and the laboratory LEMTA. It was devoted to the implementation of an emergency egress model offering prospects for use in Fire Safety Engineering. The pedestrian movement model described in this manuscript is a physical model relying on a people density balance equation. This model is based on three fundamental assumptions resulting from pedestrian phenomena commonly observed, especially in crowds. Its mathematical formulation assumes that people are regarded as a mean density in a macroscopic way. The pedestrian model was tested on verification and comparison cases extracted from literature. Evacuation drills were also performed at real scale without fire constraints to collect some quantitative data like egress times or flows, and to validate the people motion model. Furthermore, a mathematical strategy is propounded in order to integrate thermal and optical stresses into the evacuation model and to take into consideration their incidence on evacuation processes. Finally, egress simulations are achieved on a large-scale configuration considering different scenarios involving fire
Modélisation de l’évacuation des personnes en situation d’incendie
This work was conducted as a collaboration between CNPP and the laboratory LEMTA. It was devoted to the implementation of an emergency egress model offering prospects for use in Fire Safety Engineering. The pedestrian movement model described in this manuscript is a physical model relying on a people density balance equation. This model is based on three fundamental assumptions resulting from pedestrian phenomena commonly observed, especially in crowds. Its mathematical formulation assumes that people are regarded as a mean density in a macroscopic way. The pedestrian model was tested on verification and comparison cases extracted from literature. Evacuation drills were also performed at real scale without fire constraints to collect some quantitative data like egress times or flows, and to validate the people motion model. Furthermore, a mathematical strategy is propounded in order to integrate thermal and optical stresses into the evacuation model and to take into consideration their incidence on evacuation processes. Finally, egress simulations are achieved on a large-scale configuration considering different scenarios involving firesCe travail, mené conjointement entre CNPP et le Laboratoire d’Énergétique et de Mécanique Théorique et Appliquée, est consacré à la mise en place d’un modèle d’évacuation de personnes, dans l’optique d’une application en Ingénierie de Sécurité Incendie. Le modèle de cheminement de personnes développé dans ce manuscrit est un modèle physique reposant sur une équation de conservation de la densité de personnes. Il est basé sur des hypothèses simples et réalistes résultant de l’observation de mouvements de foule, et utilise une vision macroscopique des personnes caractérisées par une densité moyenne. Ce modèle est mis en œuvre sur des cas de vérification et de comparaison issus de la littérature. Des expériences d’évacuation sont réalisées à échelle réelle afin de récolter des données quantitatives sur le mouvement des personnes et de valider de façon pertinente le modèle de cheminement de personnes. En outre, une stratégie est proposée afin d’intégrer dans la modélisation les contraintes thermiques et optiques liées au feu ainsi que leur impact sur le processus d’évacuation. Enfin, des simulations d’évacuation intégrant les effets du feu sont effectuées sur une configuration à grande échell
Macroscopic egress model to compute emergency evacuations in fire situation
International audienc
Vapor phase fabrication of nanoheterostructures based on ZnO for photoelectrochemical water splitting
none9siNanoheterostructures based on metal oxide semiconductors have emerged as promising
materials for the conversion of sunlight into chemical energy. In the present study,
ZnO-based nanocomposites have been developed by a hybrid vapor phase route,
consisting in the chemical vapor deposition of ZnO systems on fluorine-doped tin oxide
substrates, followed by the functionalization with Fe2O3 or WO3 via radio frequency
sputtering. The target systems are subjected to thermal treatment in air both prior and
after sputtering, and their properties, including structure, chemical composition,
morphology, and optical absorption, are investigated by a variety of characterization
methods. The obtained results evidence the formation of highly porous ZnO nanocrystal
arrays, conformally covered by an ultrathin Fe2O3 or WO3 overlayer. Photocurrent density
measurements for solar-triggered water splitting reveal in both cases a performance
improvement with respect to bare zinc oxide, that is mainly traced back to an enhanced
separation of photogenerated charge carriers thanks to the intimate contact between the
two oxides. This achievement can be regarded as a valuable result in view of future
optimization of similar nanoheterostructured photoanodes.restrictedBarreca, Davide; Carraro, Giorgio; Gasparotto, Alberto; Maccato, Chiara; Altantzis, Thomas; Sada, Cinzia; Kaunisto, Kimmo; Ruoko, Tero-Petri; Bals, SaraBarreca, Davide; Carraro, Giorgio; Gasparotto, Alberto; Maccato, Chiara; Altantzis, Thomas; Sada, Cinzia; Kaunisto, Kimmo; Ruoko, Tero Petri; Bals, Sar
An emergency egress model based on a macroscopic continuous approach
International audienc
Insights into the Plasma-Assisted Fabrication and Nanoscopic Investigation of Tailored MnO2 Nanomaterials
Among transition metal oxides, MnO2 is of considerable importance for various technological end-uses, from heterogeneous catalysis to gas sensing, owing to its structural flexibility and unique properties at the nanoscale. In this work, we demonstrate the successful fabrication of supported MnO2 nanomaterials by a catalyst-free, plasma-assisted process starting from a fluorinated manganese(II) molecular source in Ar/O2 plasmas. A thorough multitechnique characterization aimed at the systematic investigation of material structure, chemical composition, and morphology revealed the formation of F-doped, oxygen-deficient, MnO2-based nanomaterials, with a fluorine content tunable as a function of growth temperature (TG). Whereas phase-pure \u3b2-MnO2 was obtained for 100 \ub0C 64 TG 64 300 \ub0C, the formation of mixed phase MnO2 + Mn2O3 nanosystems took place at 400 \ub0C. In addition, the system nano-organization could be finely tailored, resulting in a controllable evolution from wheat-ear columnar arrays to high aspect ratio pointed-tip nanorod assemblies. Concomitantly, magnetic force microscopy analyses suggested the formation of spin domains with features dependent on material morphology. Preliminary tests in Vis-light activated photocatalytic degradation of rhodamine B aqueous solutions pave the way to possible applications of the target materials in wastewater purification