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Conductivity and electron spin resonance measurements have been performed on solution doped polyaniline (PANi). It is proposed that both camphor-sulphonic acid (CSA) and 2-acrylamido-2-methyl-l-propanesulphonic acid (AMPSA) doped PANi can be described by the same model. It is suggested that the polyaniline materials are composed of differently ordered layers, a highly ordered region forming the core of the crystallites. The core of the crystallites are believed to be encapsulated within a semi- ordered region, with the crystallites themselves being dispersed in an amorphous polymer matrix. The conductivity measurements and ESR results described in this work support the proposal that within the highly ordered region of doped polyaniline crystallites, a polaronic lattice exists. The polaronic lattice facilitates "free" carriers which are responsible for "metallic" conduction within the crystallites. Encapsulating the polaronic lattice is a semi-ordered region in which (partially) mobile polarons (and possibly bipolarons) are present. The highly conductive crystallites are randomly dispersed in a less conductive polymer matrix. Charge transport within this heterogeneous system is well described by a heterogeneous metal - fluctuation induced tunnelling (FIT) model. The differences in the temperature dependent conductivities of the PANi-CSA and PANi-AMPSA materials are attributed to the systems having layers of different relative sizes (in the above model). AMPSA doped polyaniline films had a maximum room temperature conductivity of ~100 Scm(^-1). This material also showed potential for use as an electrode layer in polymer LEDs, to replace ITO coated glass. The conductivity of PANi-AMPSA was measured to be 50 ± 10 Scm(^-1) at thickness' of ~30nm. Layers of this thickness provide >90% optical transmission between 450 and 675 nm (most of the visible spectrum). Faraday rotation measurements have shown that the recently reported large Faraday rotation of polyaniline can not be reproduced. The limited results of the Faraday rotation experiments described in this work provide support for the theory that charge carriers in polyaniline have an effective mass of at least 100 times that of a free electron. It has also been shown that the claims of a polyaniline derivative (namely the Marcoussis polymer) being an entirely organic ferromagnet are unsubstantiated, despite intense investigation.

Polymer-fullerene blend films are of increasing interest in the field of organic solar cells. This thesis describes the use of transient absorption spectroscopy (TAS) as a means to study charge generation and recombination in these blend films. In blend films of P3HT and PCBM, the absorption spectrum associated with the positive and negative charges have been identified and the transient decay kinetics analysed to reveal the mechanisms leading to charge recombination losses in the films. The effects of annealing treatment, along with the effects of decreasing polymer regioregularity or different polymer chain terminating end-groups on the blend film properties and morphology are also discussed. For films with a low concentration of PCBM in polystyrene, absorption and emission from the individual PCBM molecules are observed. As the PCBM concentration is increased, aggregation related changes causes the absorption in the visible region to increase disproportionately, an additional emission peak at higher energies to appear and a decrease in the lifetime of the PCBM triplet excited state. These changes are linked to electronic interactions between fullerenes in a molecular crystal form of PCBM. Blends of F8BT polymer with PCBM show poor photovoltaic device performance. This is explained by the quick deactivation of the F8BT excited state by Förster energy transfer to the PCBM. As the PCBM excited state is stable compared to the charge separated state, the PCBM triplet is formed via inter-system crossing from the singlet to be the final product of photoexcitation. The high energy of the charge separated state is interpreted as a result of the high F8BT HOMO energy.

La notion de charge de travail a investi le Code du travail avec pour objectif de protéger la santé du salarié contre les risques résultant d’un excès de travail induits par les modes flexibles d’organisation du temps de travail. La présente recherche analyse ce lien entre charge de travail et protection de la santé, en déterminant les conditions de l’existence d’un tel lien, mais également en étudiant les usages et mésusages qui peuvent en résulter en droit du travail. L’approche restrictive de la charge de travail centrée sur l’excès et la surcharge entraîne une utilisation limitée de cette notion et, partant, une prévention imparfaite des risques en résultant. Cette thèse s’inscrit dans une volonté de proposer une approche renouvelée du droit de la santé au travail s’appuyant sur la notion de charge de travail raisonnable. Un basculement est à l’œuvre dans le champ de la santé au travail, d’une logique de protection de la santé contre les risques à une logique de promotion de la santé par le travail. Rechercher une charge de travail raisonnable participe de cette nouvelle logique, en permettant de ne plus penser le travail qu’en termes de risques et de favoriser les actions orientées vers la recherche d’organisations du travail saines. L’exigence systématisée d’une charge de travail raisonnable inciterait à réfléchir sur les conditions dans lesquelles le travail est effectué, à intégrer le facteur humain dans la prise de décision et à penser différemment l’organisation du travail et ses effets sur la santé. / The notion of workload appeared in the Labour Code in order to protect the employees’ health against risks stemming from an excess of work implied by flexible working time organizations. This work analyses this link between health protection and workload, by determining the conditions of existence of such a link, but also by considering the uses and misuses that may result of it in Labour Law. The restrictive approach of workload focused on excess and overload results in a limited use of this notion and thus an imperfect prevention of the resulting risks. This thesis aims to propose a renewed approach towards occupational health law, based on the notion of reasonable workload. A change is going on in the field of occupational health: the logic of health protection against risks is giving way to a logic of health promotion through work. Looking for a reasonable workload is part of this new logic, as it makes it possible to think of work not solely in terms of risks and to encourage the search for healthy work organizations. By systematizing the requirement of a reasonable workload, companies would be encouraged to integrate man into the decision-making process and to conceive differently the work organization as well as its effects on employees’ health.

Thesis (B.S.)--Massachusetts Institute of Technology, Dept. of Physics, 1982. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND SCIENCE / Includes bibliographical references. / by Igor Klebanov. / B.S.

Avec la multiplication des services dans un même réseau et les diversités des applications utilisées par les usagers finaux, le trafic transporté est devenu très complexe et dynamique. Le Partage de la Charge Dynamique (PCD) constitue une alternative intéressante pour résoudre cette problématique. Si une paire Source-Destination est connectée par plusieurs chemins, le problème est le suivant : comment distribuer le trafic parmi ces chemins de telle façon qu'une fonction objective soit optimisé. Dans ce cas les chemins sont fixés a priori et la quantité de trafic acheminée sur chaque route est déterminée dynamiquement en fonction de la demande de trafic et de la situation actuelle du réseau. Dans cette thèse nous étudions puis nous proposons plusieurs mécanismes de PCD. Tout d'abord, nous distinguons deux types d'architecture : celles dans lesquelles les ressources sont réservées pour chaque chemin, et celles pour lesquelles aucune réservation n'est effectuée. La simplification faite dans le premier type d'architecture nous permet de proposer l'utilisation d'un nouveau mécanisme pour gérer les chemins. Partant de ce mécanisme, nous définissons un nouvel algorithme de PCD. Concernant la deuxième architecture, nous étudions et comparons plusieurs fonctions objectives. À partir de notre étude, nous proposons un nouvel algorithme distribué permettant d'atteindre l'optimum de ces fonctions objectives. La principale caractéristique de notre algorithme, et son avantage par rapport aux propositions antérieures, est sa capacité d'auto-configuration, dans la mesure où la convergence de l'algorithme est garantie sans aucun besoin de réglage préalable de ses paramètres.

Electro-transmittance of molecular junctions was characterized electrically and studied optically at 410nm and 532nm. Between 1kHz and 100kHz there was no qualitative difference between the control samples and the molecular junction samples, however there were difficulties with reproducibility of the quantitative behaviour, so no hard conclusions could be drawn. A microfluidic capacitor device was designed and fabricated to study the electrical double layer, using standard microfabrication techniques. A complimentary flux corrected transport simulation was written using the same experimental geometry and the results of this study found qualitative agreement between the simulation and experiment. The experiment produced results about the concentration dependence of the double layer formation time which allows an estimate of the required frequency of an AC electrical signal for which the electrical double layer doesnt have time to form, and its effects can be ignored.

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