Search results for "Reso"
showing 10 items of 13841 documents
Alignment of linear molecules by short duration laser pulses
2005
Alignment of linear molecules is efficiently induced by strong linearly polarized laser pulses. In the case of short pulses with respect to molecular rotation, periodic alignment appears in field-free conditions after the extinction of the field. This manuscript presents three techniques where the value of allows to quantify alignment without molecular dissociation nor additional alignment. They use a weak time-delayed probe pulse which experiences the optical properties of an aligned sample and shows modification of its characteristics. The first of them measures a depolarization due to the birefringence of the sample. The second one is based on the defocusing produced by the spatial distr…
Etude spectroscopique de fibres durcies pour un environnement radiatif sévère
2013
Les nouveaux environnements radiatifs, comme LMJ, ITER, ILE/ELI, HiPER, réacteurs nucléaires des générations III+ et IV, nécessitent le développement de nouveaux composants pour le transport et le traitement des signaux. A cause de l’impossibilité d’utiliser les composants électroniques, la recherche est orientée vers les composants à fibres optiques comme vecteur d’information et aussi comme élément de diagnostic. Ils présentent de nombreux avantages, comme leur relative immunité électromagnétique, faible pois, large bande passante, mais les rayonnements gamma et les neutrons dégradent leur transmission. La dégradation dépend principalement de la composition de la fibre. Ainsi, il a été mo…
O2-Loading Treatment of Ge-Doped Silica Fibers: A Radiation Hardening Process
2016
International audience; The effects of a high-pressure O2-loading treatment on the radiation response of Ge-doped optical fibers (OFs) were investigated. We found that the incorporation of high concentration of interstitial molecular oxygen remarkably enhances the resistance to ionizing radiation of Ge-doped OFs in the UV-Visible domain and, at the same time, improves the transmission of UV light in the unirradiated OF sample. By comparison with previously reported results, the O2-loading treatment turned out to increase the radiation resistance of Ge-doped OFs more efficiently than F or Ce codoping. The understanding of such amelioration relies in basic radiation-induced mechanisms that we…
Optical properties and photosensitivity of vacuum synthesized Ge-doped sol-gel amorphous SiO/sub 2/
2005
We report optical and electron paramagnetic resonance investigations of gamma ray irradiation effects in sol-gel Ge-doped amorphous SiO/sub 2/. The studied materials have Ge-doping levels up to 10/sup 4/ molar part per million and were densified by two routes differing for the atmosphere: O/sub 2/+N/sub 2/ or vacuum. The obtained results evidence that irradiation affects matrix sites inducing paramagnetic defects. Furthermore, the comparison between the two densification procedures shows that vacuum atmosphere induces higher radiation sensitivity.
Radiation Response of Ce-Codoped Germanosilicate and Phosphosilicate Optical Fibers
2016
We report an experimental investigation on the effects of Ce-codoping in determining the radiation response of germanosilicate and phosphosilicate Optical Fibers (OFs) in the UV-Visible domain and up to doses of $1~\hbox{MGy}({\rm SiO}_{2})$ . We show that the addition of Ce strongly impacts the Radiation Induced Attenuation (RIA) of both types of fibers. In the first case the radiation induced losses increase, whereas in the second one decrease. By combining the online RIA measurements with the Electron Paramagnetic Resonance (EPR) ones, we are able to infer the basic microscopic mechanisms taking place under irradiation, which involve the cerium codopant and some of the known Ge-related o…
Synergistic photo-release of drugs by non-linear excitation
2014
ABSTRACTNanomaterials engineered in novel multi-modular systems in which every component works in a synergistic way with others could potentially lead to a completely new type of tools for nanomedicine. The development of nanostructures able to release drugs directly within the target after a stimulus can drastically improve the therapeutics efficiency by reducing side effects. Gold nanoparticles offer one of the most suitable platforms for the development of modular nano-devices. On the one hand, their surface properties enable effective coating by peptides containing at least one cysteine, thus yielding stable and non-cytotoxic systems. On the other, their intriguing photophysics, charact…
Increasing Sustainability of Growing Media Constituents and Stand-Alone Substrates in Soilless Culture Systems
2020
Peat-free growing media constituents and stand-alone substrates are the basis for the economic and ecological efficiency of the soilless culture system. Nevertheless, divergence between the model and practice still exists, coming from large gaps in the knowledge of alternative organic materials and of their effects on crop performance. A more detailed understanding of these topics is necessary to increase the soilless culture management capacity. In this respect, this critical review collects research outcomes concerning the sustainability of soilless culture and growing media constituents and their impact on the environment. In particular, the review covers designated articles stressing th…
Peer interaction and pioneering organizational form adoption : A tale of the first two for-profit stock exchanges
2021
Building on a historical case study on the first two stock exchanges to adopt the now globally dominant for-profit organizational form, the Stockholm Stock Exchange in 1993 and the Helsinki Stock Exchange in 1995, we argue that interaction among socially proximate peers contributes to pioneering organizational form adoption within an industry, particularly when such forms are introduced by established organizations. Peer interaction can induce a search for technically efficient organizational forms through the sharing of collective experiences, the establishment of collective assumptions, and a joint search for solutions. Together, these factors contribute to the legitimization of novel or…
Structural Correspondence Between Organizational Theories
2021
AbstractOrganizational research constitutes a differentiated, complex and fragmented field with multiple contradicting and incommensurable theories that make fundamentally different claims about the social and organizational reality. In contrast to natural sciences, the progress in this field can’t be attributed to the principle of truthlikeness where theories compete against each other and only best theories survive and prove they are closer to the truth and thus demonstrate scientific knowledge accumulation. We defend the structural realist view on the nature of organizational theories in order to demonstrate that despite the multiplicity of isolated and competing explanations of organiza…
Deinstitutionalization revisited
2021
PurposeThe purpose of this paper is to offer a new analysis and understanding of the notion of deinstitutionalization. Deinstitutionalization of taken-for-granted practices as a natural consequence of ever-increasing entropy seems to directly contradict the major institutional thesis, namely, that over time isomorphic forces increase and, as a result, possibilities for deinstitutionalization decrease culminating in the impossibility of abandoning in highly institutionalized fields.Design/methodology/approachThis paper is conceptual in nature. Oliver’s 1992 paper on deinstitutionalization is taken as a key text on the subject and as a starting point for building an alternative theory of dein…