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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Apport des liquides ioniques aprotiques à la sécurité des électrolytes pour supercondensateurs / Contribution of aprotic ionic liquids to the safety of supercapacitors electrolytes

Abdallah, Thamra 28 June 2012 (has links)
L‟acétonitrile (ACN) peut être considéré comme le solvant de référence utilisé dans les électrolytes pour supercondensateurs car, industriellement, il est le plus utilisé. Il présente en effet de nombreux avantages tels qu‟une viscosité faible et une permittivité élevée, conduisant à une excellente conductivité en présence d‟un sel. Il est cependant hautement volatile, très inflammable et toxique quand il brûle (dégagement de HCN). Ainsi, dans le but de réduire sa pression de vapeur, et donc le risque d‟inflammabilité, il peut être mélangé à un liquide ionique (LI) qui lui est non volatile. Le but de ce travail est de remplacer l‟électrolyte classique des supercondensateurs à base de ACN et de sel de tétraethylammonium tétrafluoroborate (ACN + 1M Et4N+BF4-) par un mélange LI/ACN. Pour ce faire, l‟étude physico-chimique, électrochimique et thermodynamique des mélanges LI/ACN est entreprise. Dans un premier temps, les liquides ioniques ont été synthétisés et caractérisés par différentes techniques d‟analyses physico-chimiques. Ensuite des mélanges LI/ACN ont été formulés. Ces mélanges ont subi des tests de sécurité (tests préliminaires d‟inflammabilité, mesures de point flash) afin de trouver le mélange optimal. Les phénomènes de transport dans ces mélanges ont été aussi étudiés afin de comprendre leur comportement en température. Par ailleurs, l‟étude électrochimique menée sur ces mélanges a montré qu‟il n‟y avait pas de dégradation des performances électrochimiques par comparaison à l‟électrolyte classique. Enfin l‟étude de l‟équilibre liquide vapeur à partir de modèles thermodynamiques semi-prédictifs comme UNIQUAC ou prédictifs comme Cosmo-RS a permis de déterminer les grandeurs d‟excès. / Acetonitrile (ACN) is the most popular solvent in electrolytes designed for use in supercapacitors. It presents many advantages such as a low viscosity and a high permittivity, leading to excellent conductivities in the presence of salts. However it is highly flammable and very toxic when burning (release of HCN ). Thus, in order to reduce its vapor pressure and hence its flammability we propose to mix it with an ionic liquid (IL). As ILs are non volatile compounds, the vapor pressure of the mixture will be reduced (Raoult‟s law). In addition many other benefits may be expected from these mixtures. The aim of this work is to replace the conventional ACN and Et4NBF4 based electrolyte for supercapacitors by a IL/ACN mixture. Thus, the physico-chemical, electrochemical and thermodynamical studies of IL/ACN mixtures have been undertaken. Synthesized and commercial ILs are characterized by mean of different physico-chemical analysis. Then IL/ACN mixtures were formulated. These mixtures were tested for safety (preliminary flammability tests, flash point measurements) and the optimal mixture determined. Transport phenomena in these mixtures were also studied to understand their behavior in response to temperature. Furthermore, the electrochemical study conducted on these mixtures showed that there was no degradation of the electrochemical performances as compared to the conventional electrolyte. Finally the study of vapor liquid equilibrium from semi-predictive thermodynamic models like UNIQUAC or predictive models like Cosmo-RS allowed us to determine the excess properties.
2

Berry fruit anthocyanins in human nutrition : bioavailability and antioxidant effects : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Nutritional Science at Massey University, Palmerston North, New Zealand

Walton, Michaela C. January 2006 (has links)
Anthocyanins (ACNs), which are responsible for the red and blue colours displayed by many vegetables and fruits (particularly berries), belong to secondary plant metabolites, and are a component of our daily diet. There is an increasing interest on their biological activities as they are claimed to enhance health by protecting against some chronic diseases. However, before ACNs can perform health-promoting effects in vivo, they must first be sufficiently absorbed, distributed within the human body, and reach target tissues in adequate concentrations. To date, all studies investigating ACN absorption and metabolism came to the conclusion that their bioavailability is extremely low. To benefit from the proposed health effects of ACNs, their bioavailability, including absorption, metabolism, and excretion must first be understood. The main objective of this thesis was to provide further knowledge on ACN absorption, including the absorption site and mechanism, and the influence of food and other flavonoids on ACN absorption, as well as the investigation of their antioxidant effects in vivo. In vitro experiments using Ussing chambers showed that a strong absorption of ACNs occurred from the jejunum in mice. This was supported with a further in vivo study, where the major absorption site for ACNs may be the jejunum in rats. The limitation of ACN absorption to mainly one part of the intestine suggested the participation of a particular transport mechanism. In a further Ussing chamber study it was shown that flavonols, another common flavonoid group present in many fruits and vegetables, strongly inhibit ACN absorption, indicating a specific transport mechanism, with preference for other flavonoid compounds. Further in vivo studies have shown that the simultaneous ingestion of food components, such as breakfast cereals, resulted in a delayed absorption profile in two animal species. However, the additional food did not influence the antioxidant effect of ACNs. During a human intervention study, several measures of oxidative stress improved, but this improvement occurred equally in the treatments and placebo control, and may have resulted from changes in lifestyle. The results of these studies aid to understand details of ACN absorption and help to formulate future recommendations for ACN intake with increased bioavailability in humans.
3

Customer Acquisition Training for ACN Independent Representatives

Shippen, Kaly Gillette 20 December 2005 (has links) (PDF)
The following report discusses the design, development, and evaluation of an online training on customer acquisition of telephone customers for a telecommunications company called ACN. The report includes a description of the following elements of the project: (a) the need and purpose for the instruction, (b) the target audience of the instruction, (c) the methodology and rationale for the design of the instruction based on relevant literature, (d) an existing materials search, (e) the instructional materials, (f) the evaluation, (g) the critique, (h) the schedule, and (i) the final budget report. The instruction was found to effectively teach learners the intended objectives which related to understanding the ACN approach to customer acquisition and how to answer common customer questions. Learners in the small group test gained an average of 58.8% on the posttest following completion of the instruction. In addition, qualitative feedback from learners was positive, with all of the learners suggesting that the instruction was helpful, well organized, and accessible. Content experts indicated that the instruction complemented the current ACN training system and that the essential content was covered in a logical manner, and design experts indicated that proper instructional design and web-based training principles were implemented.
4

Telematik und Telemedizin zur Verbesserung der präklinischen Notfallversorgung nach Straßenverkehrsunfällen

Issing, Matthias Michael 17 May 2006 (has links)
Die Überlebenswahrscheinlichkeit der Unfallopfer nach Straßenverkehrsunfällen hängt von der Zeitspanne vom Unfall bis zur ersten suffizienten Hilfeleistung (therapiefreies Intervall) sowie von der Qualität der Erstversorgung ab. Das therapiefreie Intervall kann durch automatische Notrufsysteme (ACN) und suffiziente Laienhilfe verkürzt werden. In dieser Dissertation werden (1) Modelle zur Prognose der Verletzungsschwere von Fahrzeuginsassen für den Einsatz in erweiterten automatischen Notrufsystemen (AACN) entwickelt und (2) Anforderungen an Telemedizinsysteme zur Unterstützung von Laien bei der Durchführung von Erste-Hilfe-Maßnahmen untersucht. (1) Die Prognose der Verletzungsschwere ist für eine optimale Disposition der Rettungsmittel erforderlich. Auf der Basis der amerikanischen Unfalldatenbank NASS/ CDS und der deutschen Unfalldatenbank GIDAS werden Prognosemodelle mit multivariaten inferenzstatistischen Verfahren (decision tree, logistic regression) entwickelt, die Bedeutung einzelner Eingangsgrößen untersucht und die Leistungsfähigkeit der Modelle überprüft. Die Leistungsfähigkeit beider statistischen Verfahren stellt sich in ROC-Analysen als vergleichbar heraus. Mit den Prognosemodellen kann eine Dispositionsempfehlung erstellt werden, die heutigen Dispositionsentscheidungen auf der Grundlage eines Telefongesprächs mit dem Unfallmelder qualitativ entspricht. (2) Zur Entwicklung eines Telemedizinsystems für die Laienunterstützung wird untersucht, ob die telemedizinische Anleitung von Laien bei der Durchführung von Erste-Hilfe-Maßnahmen zu einer Erhöhung der Hilfsbereitschaft führt und welche Anforderungen ein Telemedizinsystem erfüllen muss. Dazu werden die am häufigsten indizierten Erste-Hilfe-Maßnahmen nach Verkehrsunfällen durch Auswertung der GIDAS-Datenbank identifiziert, der Stand der heutigen Laienhilfe analysiert, die erforderlichen Funktionen eines Telemedizinsystems abgeleitet und der Einfluss einer verbesserten Laienhilfe auf die Überlebenswahrscheinlichkeit bestimmt. / The probability of survival of motor vehicle accident victims depends on two factors: the time interval between the accident and the initial provision of appropriate first-aid (therapy-free interval), and the quality of the first-aid treatment. The therapy-free interval can be shortened significantly by automatic crash notification systems (ACN) and by adequate bystander first aid. In this thesis, (1) models are developed for predicting the severity of injury of vehicle occupants for use in advanced automatic crash notification systems (AACN) and (2) requirements of telemedical bystander support systems are examined. (1) The prediction of the severity of injury is needed for optimal disposition of rescue services. Therefore, prediction models are developed on the basis of the American accident database NASS/ CDS and its German counterpart, GIDAS, using multivariate inference statistical procedures (decision tree, logistic regression). In addition, the importance of individual parameters and the efficiency of these models are investigated. The performance of the two statistical procedures proves to be equal by using the ROC analyses. The prediction models allow for recommendations of rescue services that correspond in quality to contemporary dispatching decisions for rescue services on the basis of a telephone call between the individual reporting the accident and a dispatcher. (2) Concerning the development of a telemedical bystander support system, the paper examines whether the availability of telemedical guidance leads to an increase in bystander willingness to provide first aid. In order to evaluate the requirements of a telemedical system, the most frequently indicated first-aid measures after traffic accidents are identified by evaluating the GIDAS database. Furthermore, the status of assistance currently offered by bystanders is analyzed, the necessary functions of a telemedical system are scrutinized, and the influence of improved bystander assistance on the probability of accident victims’ survival is determined.
5

El rol de los CCTT como intermediarios de innovación: un análisis mutidimensional.

Del Campo Asenjo, Cristina 18 December 2023 (has links)
[ES] Los centros tecnológicos (en adelante, CCTT) son uno de los agentes clave de los sistemas de innovación (en adelante, SI) y actúan como pieza fundamental para fomentar y apoyar la innovación empresarial a través de la tecnología. El objetivo principal de esta tesis ha sido el estudio del rol de los CCTT en diferentes contextos identificando, a través de varias técnicas de análisis cuantitativas y cualitativas, su papel como intermediarios de innovación en los SI, así como los factores y variables clave para su competitividad. Para ello, en la primera parte de esta tesis se ha investigado sobre los SI, con el objetivo de analizar el entorno en el que operan los CCTT, aplicando tanto el método comparativo a través del estudio del caso de varios SI de referencia a nivel internacional, como la metodología del Análisis de las Condiciones Necesarias para identificar los factores críticos de mayor incidencia en la innovación y la competitividad de un territorio. La segunda parte de la tesis se ha dedicado a la investigación sobre los intermediarios de la innovación, analizando de forma particular el rol de los CCTT mediante la aplicación de la metodología del Análisis Cualitativo de Datos a la revisión bibliométrica de las publicaciones sobre CCTT. Por último, se ha aplicado la metodología del Proceso de Análisis Jerárquico para identificar y priorizar los elementos que inciden en la eficiencia y la competitividad de un CT. Con todo ello, se establecen conclusiones de utilidad tanto para la mejora de la gestión de los CCTT, como para el establecimiento de políticas de innovación que tengan como resultado una mayor eficiencia de los propios Centros, así como un incremento de la competitividad del territorio. / [CA] Els Centres Tecnològics (d'ara en avant, CCTT) són un dels agents clau dels Sistemes d'Innovació (d'ara en avant, SI) i actuen com a peça funda per a fomentar i donar suport a la innovació empresarial a través de la tecnologia. L'objectiu principal d'esta tesi ha sigut l'estudi del rol dels CCTT en diferents contextos identificant, a través de diverses tècniques d'anàlisis quantitatives i qualitatives, el seu paper com a intermediaris en els SI, així com els factors i variables clau per a la seua competitivitat. Per a això, en la primera part d'esta tesi s'ha investigat sobre els SI, amb l'objectiu d'analitzar l'entorn en què operen els CCTT, aplicant tant el mètode comparatiu a través de l'estudi del cas de diversos SI de referència a nivell internacional, com la metodologia de l'Anàlisi de les Condicions Necessàries per a identificar els factors crítics de major incidència en la innovació i la competitivitat d'un territori. La segona part de la tesi s'ha dedicat a la investigació sobre els intermediaris de la innovació, analitzant de forma particular el rol dels CCTT per mitjà de l'aplicació de la metodologia de l'Anàlisi Qualitativa de Dades a la revisió bibliométrica de les publicacions sobre CCTT. Finalment, s'ha aplicat la metodologia del Procés d'Anàlisi Jeràrquica per a identificar i prioritzar els elements que incidixen en l'eficiència i la competitivitat d'un CT. Amb tot això, s'establixen conclusions d'utilitat tant per a la millora de la gestió dels CCTT, com per a l'establiment de polítiques d'innovació que tinguen com resultat una major eficiència dels propis Centres, així com un increment de la competitivitat del territori. / [EN] Technology Centers (hereinafter, TTCC) are one of the key agents of Innovation Systems (hereinafter, IS) and act as a fundamental piece to promote and support business innovation through technology. The main objective of this thesis has been to study the role of TTCC in different contexts by identifying, through various quantitative and qualitative analysis techniques, their role as intermediaries in IS, as well as the key factors and variables for their competitiveness. To this end, the first part of this thesis has investigated the IS, with the aim of analyzing the environment in which the TTCC operate, applying both the comparative method through the case study of several international reference IS, and the methodology of the Necessary Conditions Analysis to identify the critical factors of greater impact on the innovation and competitiveness of a territory. The second part of the thesis was devoted to research on innovation intermediaries, analyzing in particular the role of the TTCC by applying the Qualitative Data Analysis methodology to the bibliometric review of publications on TTCC. Finally, the Hierarchical Analysis Process methodology has been applied to identify and prioritize the elements that affect the efficiency and competitiveness of a TC. With all this, useful conclusions are drawn both for the improvement of the management of the TTCC and for the establishment of innovation policies that will result in greater efficiency of the centers themselves, as well as an increase in the competitiveness of the territory. / Del Campo Asenjo, C. (2023). El rol de los CCTT como intermediarios de innovación: un análisis mutidimensional [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/201137

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