50 research outputs found
The importance of hydrogen bond in a new hybrids compound
Get PDFOrganic inorganic compounds constitute a vast family of hybrid materials of considerable technological importance. Indeed, due to the nature (molecular, ionic, hydrogen bonding, etc...) of organic and inorganic components, many combinations may be achieved to elaborate suitable materials, so as to exhibit some interesting crystal structure and some special properties in several areas, such as nonlinear optical (NLO), magnetism, luminescence, photography and drug delivery, etc [1]. Moreover, hydrogen bonding is of intense interest because of their widespread occurrence in biological systems. So, it is very helpful to search simple molecules allowing to understanding the configuration and the function of some complex molecules. The hybrid compounds are rich in H-bonds and they could be used to this effect because of their potential importance in constructing sophisticated assemblies from discrete ionic or molecular building blocks due to its strength and directionality [2]. In order to enrich the varieties in such kinds of hybrid materials and to investigate the influence of hydrogen bonds on the on the structural features, they have synthesized a new compound, This kind of hydrogen bonding appears in the active sites of several biological systems and is observed in similar previously studied hybrid compounds [3, 4, 5].The combination of the organique matrix and the mineral anions allowed us to obtain original structures [6,7]. Our current domain of research consists the study of the hydrogen connections in a series of hybrids compound, To do it, we are going to use the potentialities which offers the ADF software (Amsterdam Density Functional ) to study this type chap of compounds under solid (determination of gaps, level of fermi etc……).
Entre mode de raisonnement et mode d’interaction. L’argumentation dans l’action collective comme source de capacités citoyennes ?
No full textThis article questions the (in)capacities of citizens based on the argumentative constraint imposed on mobilizations of actors in public space. The author suggests that the actors’ capacity to simultaneously manage the epistemic dimension and relational dimension of argumentation is determinant in this problematic. Three dimensions of collective action are discussed from this aspect : situated commitment, formation of a collective commitment and axiological convergence in exchanges of sociability
Converted waves in shallow marine environments: Modelling and field experiments
No full textThe shallow marine subsurface is explored for various engineering purposes e.g. constructing installations and platforms, laying pipelines and dredging for sand. Knowledge of the soil properties is essential to minimize the risks involved with these offshore activities. Energy resources in the form of gas hydrates and hydrocarbon reservoirs are often found a few hundred meters to a few kilometers below the seafloor. Accurate estimates of the sediments properties at shallow depths may considerably improve the image at the target depth. Seismic waves converted from compressional (P-) to shear (S-) mode can be useful to retrieve these properties. The acquisition and processing of converted-wave data in shallow marine environments remains challenging. This is due to the high velocity ratio between the P- and the S-wave in the sediments. In this thesis, the acquisition and processing of converted waves is addressed through field experiments and synthetic modelling.GeotechnologyCivil Engineering and Geoscience
Love, Lebanese style: Toward an either/and analytic framework of kinship
Get PDFThis is the author accepted manuscript. The final version is available from Duke University Press via the DOI in this recordThis article draws on a year of fieldwork conducted in Lebanon to highlight the paradoxical entanglement of power with romantic love in Lebanon, evident in the intricate gendered, aged, classed, and sect-related negotiations that accompany courtship periods. In addition, the article highlights the inclusive and relational qualities that external kin relations conduce. Kin approval ought not be seen as either/or divisive/conditional. For many of the couples interviewed, kin relations constitute an arena in which they can disseminate their affective bond. Such analysis is threefold. In addition to embracing the multiple subjectivity of the interlocutors, it moves beyond the standard political-economic approach that generally informs marriage studies in the Middle East and dismantles monolithic perceptions of Middle Eastern kin networks
Queering Heterosexual (inter-sectarian) Love in Lebanon
No full textThis is the author accepted manuscript. The final version is available from Cambridge University Press via the DOI in this recordThis article draws on a year of ethnography conducted among cis heterosexual couples in contemporary urban Lebanon in order to argue that, in the absence of a serious project of national reconciliation, intersectarian love, despite its short lifespan, constitutes restorative instances in post–civil war Lebanon. Intersectarian hetero desire emerges as a counter-discourse that threatens the masculinist foundations of the Lebanese state. By tracing the timeline of love in the life of Lebanese citizens, this article places personal narratives of “impossible” intersectarian love stories in conversation with queer temporality scholarship in order to recognize the political, albeit limited, potential of romantic love. Here, societal expectations of married life are replaced by an ephemeral unity that operates in contra to hegemonic interpretations of “man and wife.
DOUBLE RESONANCE EXCITATION OF THE RUBIDIUM DIMER : THE 2 STATE
No full textAuthor Institution: Department of Chemistry, Moscow State University, 119991; Moscow, Russia\; Institut Lumiere Matiere, Universite Lyon 1 \& CNRS UMR5306, Universite de Lyon, FranceWe have performed a series of optical-optical double resonance experiments with one or two cw Ti:sapphire lasers, to excite the 2~ state of Rb, recording infrared fluorescence from 2~ on a Fourier transform spectrometer. Fluorescence from the lower vibrational levels of 2~ (T = 22069.56 cm) is dominated by transitions to the B state studied by Amiot and Verges, Chem. Phys. Lett. 294, 91-98 (1997). Vibrational and rotational relaxation from laser-pumped levels v' 35, occurs also to the 0 components of the A~b complex. Fitting all available 2~B~ data for Rb and RbRb (several thousand transitions) has also given an improved description of the bottom of the B state potential well. The 2~ state correlates at long-range with Rb 5s + Rb 4d atoms (A.-R. Allouche, M. Aubert-Frecon, J. Chem Phys 136, 37-41 (2012)), giving a dissociation energy of 1279.6 cm. Most new data lie below v = 45, 250 cm below this dissociation threshold
Shear Waves in Streamer Data via Nongeometrical Conversions
Get PDFIn this paper we show that when an airgun source and a hydrophone streamer are situated in the vicinity of the water bottom, shear-related events are generated via the evanescent part of the P wave in the water. The shear-related events are not only the often-used surface/Scholte waves but also body Swaves which can be reflected/refracted in the subsurface. The gain of this approach that neither source nor receiver is making any contact with the water bottom itself, making it possible to do shear-wave surveys on water in an efficient manner. We show that such shear-wave events are observed in real data, and can be reproduced by modelling. The results are further validated via real measurements in a borehole.Geoscience & EngineeringCivil Engineering and Geoscience
Les facteurs cognitifs de l’objectivation du territoire : relations épistémiques et représentations dans la gestion de l’eau en Camargue
No full textCet article aborde la problématique du territoire selon une perspective émergente en sociologie, l’étude des dimensions cognitives et épistémiques de la gouvernance et de la démocratie participative. Il se concentre sur le travail collectif d’objectivation du territoire rendu nécessaire par sa gestion collective pour interroger l’intégration des représentations des habitants et des savoirs profanes au processus de décision. En considérant les propriétés épistémiques et cognitives de l’objectivation, l’auteur identifie deux processus limitant l’intégration des connaissances profanes et des représentations locales à la définition du territoire de projet : la dynamique des relations épistémiques et les modalités d’apprentissage organisationnel sous forme de règle de gestion. L’article prend pour cas d’étude la gestion collective de l’eau en Camargue (France, Bouches-du-Rhône) et s’appuie sur l’observation sociologique d’une commission participative réalisée de 2009 à 2012.This article is an attempt to address the issue of territory by an emerging perspective in sociology: the study of cognitive and epistemic dimensions of governance and participatory democracy. In order to examine the integration of the inhabitants’ representations and of the lay knowledge in decision-making, it focuses on the collective work of objectification of the territory necessary to the collective management. Analyzing the epistemic and cognitive properties of objectification, the author identifies two processes limiting the integration of lay knowledge and local representations to the definition of the project territory: the dynamic of epistemic relations and the realization of the organizational learning by creating rules of management. The article relies on a case study corresponding to the collective water management in the Camargue (France, Bouches-du-Rhône) that necessitated the sociological inquiry of a participatory commission conducted from 2009 to 2012
Monitoring of rapid sand filters using an acoustic imaging technique
No full textA novel instrument is developed to acoustically image sand filters used for water treatment and monitor their performance. The instrument consists of an omnidirectional transmitter that generates a chirp with a frequency range between 10 and 110 kHz, and an array of hydrophones. The instrument was extensively tested in a lab before being deployed in an industrial rapid sand filter, made available by a Dutch drinking water company. This filter was monitored over a period of 10 days. We performed a scan every two hours. The obtained images are processed and compared. Clear changes in acoustic response were detected mainly at the top 20 cm of the filter bed. Two important observations can be made from the analysed data. First, the filter bed is compacting during filtration. This seems to be linearly increasing with the filter run time. The second effect is the relative acoustic “transparency” of the filter bed directly after backwashing. Small-scale accumulations of particles are detected. These observations show the great potential of this acoustic-based tool in monitoring the performance of a rapid sand filter.Water ManagementCivil Engineering and Geoscience
Les conflits d'aménagement dans la communication environnementale: argumentation et dissémination de contenus environnementaux
Get PDFThis paper examines the influence that land use conflicts have on adherences to environmental ideas and values. By referring to a case study and emerging from the obligation to argue about what stakeholders encounter, the author analyses different processes. These processes lead to disseminate environmental values and ideas as they reinforce the commitment to pro-environmental attitudes. The epistemic dimension of debates can nevertheless exert a counter-effect on these processes
