Dissertations / Theses: 'Charge energie'

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Doyen-Lang, Sandrine. "Transfert de charge dans les composés d'insertion du graphite et du fullerène." Metz, 1993. http://docnum.univ-lorraine.fr/public/UPV-M/Theses/1993/Doyen_Lang.Sandrine.SMZ933.pdf.

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Cette thèse est consacrée à l'étude théorique des propriétés électroniques et plus particulièrement du transfert de charge dans les composés d'insertion du graphite et du fullerène (LiC6CaC6, SrC6, BaC6, SmC6, EuC6, YbC6, RbR8, CsC8, KC2, KC3, KC6 et KC8, Cs3C60, Rb3C60, K3C60, RbK2C60, CsK2C60, KRb2C60, CsRb2C60 et RbCs2C60). L'énergie (cinétique+potentielle+madelung) des composés est calculée en fonction de l'ionicité, le minimum d'énergie nous donnant la valeur de l'ionicité pour laquelle le composé est le plus stable, cette valeur correspond au transfert de charge du composé. Le transfert de charge est calculé pour l'ensemble des composés ainsi que leurs énergies de cohésion (les différentes énergies correspondant aux transformations successives du composé lors de sa formation y sont evaluées). Enfin l'évolution de ce même transfert de charge en fonction de différents paramètres physiques (concentration de l'inséré et température critique de supraconductivité) y est étudiée
In this thesis we study the electronical properties and in particular the charge transfer of some grpahite and fullerene intercalation compounds (LiC6CaC6, SrC6, BaC6, SmC6, EuC6, YbC6, RbR8, CsC8, KC2, KC3, KC6 et KC8, Cs3C60, Rb3C60, K3C60, RbK2C60, CsK2C60, KRb2C60, CsRb2C60 et RbCs2C60). The energy (kinetic + potential+Madelung) of the compounds is calculated as a function of the ionicity, the minimum of energy gives the value of the ionicity corresponding to the most stable state which corresponds to the charge transfer. The charge transfer is calculated for all those compounds. The cohesive energy is also calculated (by taking in account the different values corresponding to the successive transformations of the compound during his formation. Finally the evolution of charge transfer as a function of physical parameters (intercalated metal concentration and critical temperature of superconductivity) is studied

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Concina, Bruno. "Effets de l'énergie interne sur l'évaporation unimoléculaire, la photoévaporation et la fission de petits agrégats atomiques : Approches expérimentales et théoriques." Paris 11, 2002. http://www.theses.fr/2002PA112185.

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Cette thèse est consacrée aux effets de température sur l'évaporation et la fission de petits agrégats atomiques. L'étude de l'énergie cinétique libérée par évaporation unimoléculaire a été menée sur de petits agrégats de sodium et de strontium. Elle permet de caractériser de manière fine le phénomène même d'évaporation. Ainsi, la comparaison entre l'expérience et un modèle statistique met en évidence les effets dus à la rotation de l'agrégat fils et à l'anharmonicité de ses vibrations (dans le cas des agrégats de sodium). Nous avons également étudié le rôle de la position de l'état de transition (pour les agrégats de strontium). Nous avons prolongé cette étude par celle de l'énergie cinétique libérée par photoévaporation de petits agrégats de strontium : les mesures sont comparées aux prédictions d'un modèle statistique qui décrit les cascades de photoévaporations en tenant compte de la distribution d'énergie interne des agrégats. Tout comme l'absorption d'un photon, l'interaction avec un atome peut donner lieu à un dépôt d'énergie. Certaines collisions d'échange de charge entre agrégats d'alcalins doublement chargés et atomes alcalins en sont un exemple. Nous avons estimé le dépôt d'énergie associé à ces échanges de charge par l'analyse de l'évaporation post collisionnelle. Cette thèse a également porté sur la fission d'agrégats d'alcalins doublement chargés. Nous avons déterminé expérimentalement l'importance relative des canaux de fission. Celle-ci ne peut être expliquée de manière satisfaisante que grâce à la prise en compte d'effets thermodynamiques
This thesis deals with the temperature effects on the evaporation and the fission of small atomic clusters. The study of the kinetic energy released by unimolecular evaporation has been carried out on small sodium and strontium clusters. It allows the detailed characterization of the evaporation process. The comparison between the experiment and a statistical model shows the effects due to the sub-cluster rotation and the anharmonicity of its vibrations (in the case of sodium clusters). We have also studied the role of the transition state position (for strontium clusters). As an extension of this work, we have studied the kinetic energy released by photoevaporation of small strontium clusters : the measurements are compared to the predictions deduced from a statistical model. This model describes the series of photoevaporations taking into account the internal energy distribution of the clusters. Like for a photon absorption, the interaction with an atom can lead to an energy deposit. It is the case of some charge exchange collisions between doubly charged alkaline clusters and alkaline atoms. We have evaluated the energy deposit associated to these charge exchanges by the analysis of the post-collision evaporation. This thesis also deals with the fission of doubly charged clusters of alkaline atoms. We have experimentally determined the relative weight of the fission channels. These results are explained by thermodynamical effects

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Nepor, František. "Laboratorní elektronická zátěž s USB rozhraním." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2011. http://www.nusl.cz/ntk/nusl-219138.

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Design and realisation of electronic regulated ballast with USB interface. The ballast has three functions: constant I, constant U and constant R. This device is intended for example to measure discharge curves of accumulators.

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BRAGA, DELFIN. "ETUDE DES PHENOMENES DE CHARGE DES MATERIAUX ISOLANTS SOUS FAISCEAU D'ELECTRONS DE BASSE ENERGIE (200 eV - 30 keV)." Phd thesis, Université Paris Sud - Paris XI, 2003. http://tel.archives-ouvertes.fr/tel-00004341.

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Les phénomènes de charge des isolants ont été étudiés à l'aide d'un microscope électronique à balayage qui permet d'injecter de très faibles doses d'électrons dans une large gamme d'énergie et de mesurer simultanément l'émission électronique secondaire et la charge générée dans le matériau par influence. Les résultats obtenus ont permis de montrer que le rendement électronique secondaire est un bon moyen de caractériser l'état de charge d'un isolant et de classer ces matériaux en deux grandes classes selon leur capacité à relaxer les charges générées : · Les "piégeurs", de fortes résistivités, piégent de manière stable les charges pendant des mois. · Les "conductifs", de résistivités plus faibles, relaxent les charges plus ou moins rapidement selon la densité et la mobilité des charges intrinsèques au matériau. Les résultats obtenus ont également montré que le paramètre fondamental qui contrôle la cinétique de charge des isolants est la densité de courant primaire J0. Pour les "piégeurs", différents régimes de charge (autorégulé, vieillissement, dégradation) fonction de la densité de courant J0 et du domaine d'énergie considéré ont été observés. L'étude des "conductifs" a révélé l'existence d'un courant permanent au sein de ces matériaux, caractérisé par le rendement stationnaire qui permet de fixer la valeur limite de J0 que peut supporter un "conductif" sans accumulation de charges. Ces résultats ont permis de définir quel type de matériau devait être utilisé d'un point de vue électrique pour réduire voire annuler la déviation des électrons par les espaceurs des écrans plats à effet champ, mais aussi de mettre en place une nouvelle voie d'exploration du champ interne produit par polarisation thermique d'échantillons vitreux. Nous avons également développé une nouvelle voie d'exploration de l'évolution spatio-temporelle des charges piégées sur les isolants "piégeurs" grâce à l'utilisation d'un microscope à force électrostatique. Les premiers résultats montrent la grande stabilité des charges au sein de ces matériaux.

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Leclaire, Thomas. "Entwicklung eines Verfahrens zur Erzeugung monodisperser Partikel mit definierter elektrischer Ladung / Development of a method for generating monodisperse particles having a predefined electrical charge." Gerhard-Mercator-Universitaet Duisburg, 2005. http://www.ub.uni-duisburg.de/ETD-db/theses/available/duett-11082005-180328/.

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Theoretical models describing the kinetic and evaporation as well as the electrical charge of droplets in a droplet chain generated by a vibrating orifice generator are presented. The models are verified by experimental results. Droplet charge and the electrical current transported by the droplet chain are correlated with the length of the liquid jet. Based on these results, an apparatus for generating neutral or predefined charged particles has been developed, whereby not only the average charge of the particle collective, but also the charge of individual droplets can be defined. The applicability in generating solid particle aerosols by jet dispersion of solutions are disclosed.

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FLORESCU, ANCA-IRINA. "Traitement semiclassique de l'echange de charge vibronique dans les collisions ion-molecule a basse energie (1-100 ev/u. M. A. )." Paris 11, 1994. http://www.theses.fr/1994PA112205.

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Le present travail constitue une etude theorique des processus d'excitation vibrationnelle et d'echange de charge vibronique dans les collisions ion-molecule dans le domaine d'energie 1-100 ev/u. M. A. , par une methode semiclassique multitrajectoire (mscmt). Cette methode est d'abord introduite dans le contexte de l'approximation infinite-order-sudden (ios: mouvement relatif ion-molecule unidimensionnel), puis est generalisee a trois dimensions dans le cadre de l'approximation du rotateur gele. La methode semiclassique multitrajectoire elimine le dilemme du choix de la trajectoire classique, inherent aux traitements semiclassiques anterieurs, en prescrivant: (i) une trajectoire par paire d'etats couples et (ii) une trajectoire pour le facteur de phase accompagnant chaque amplitude de probabilite. La methode est appliquee aux systemes h#+ + o#2 et h#+ + h#2. Dans le premier cas les surfaces de potentiel utilisees proviennent d'une methode de potentiel modele effectif. Dans le second cas les surfaces de potentiel sont d'abord obtenues par une methode dimzo puis corrigees par comparaison avec un calcul ab initio. Les resultats obtenus (probabilites de transition en fonction du parametre d'impact, sections efficaces differentielles etat-a-etat) sont compares a des calculs anterieurs (quantiques ios, semiclassiques monotrajectoire) et a des donnees experimentales. Toutes ces comparaisons prouvent que la mscmt est la plus performante parmi les methodes semiclassiques existantes et, dans sa variante unidimensionnelle, equivalente a la methode quantique ios

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Ali, Ahmad Mouhamad. "Energie de surface de nanoparticules de TiO2-anatase. Mesure des effets de taille, morphologie et cristallinité par molécules sondes." Thesis, Montpellier 2, 2011. http://www.theses.fr/2011MON20182/document.

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Afin d'étudier la granulo- et la morpho-dépendance des propriétés d'énergies de surface de solides divisés, plusieurs lots de TiO2 anatase ont été synthétisés. Une série de matériaux parfaitement définis avec des morphologies allant de sphéroïdale à facettée, dans des gammes de tailles allant de 4 à 20 nm a été obtenue grâce aux modifications de conditions de pH et la présence d'acides organiques. La combinaison de différentes molécules sonde a permis de déterminer l'hétérogénéité énergétique superficielle de ces matériaux, aux interfaces solide/gaz et solide/liquide. La volumétrie de quasi-équilibre à basse pression (N2/Ar) couplée à la méthode de modélisation DIS et la microcalorimétrie à écoulement de gaz (NH3) ont mis en évidence les contributions des différentes faces cristallographiques et les effets de la cristallinité. Ces mêmes propriétés ont été analysées grâce à la titration potentiométrique en milieu aqueux (H+/OH-), couplée à la procédure TDIS (détermination du PCN et des distributions d'affinité de protons). Cette stratégie a permis une étude complète des propriétés superficielles énergétiques et géométriques des nanomatériaux
In order to study the relationships between the particle size, the morphology and the surface energy properties of divided solids, several batches of TiO2 anatase were synthesized. A series of materials with morphologies ranging from spheroidal to well faceted, with particle sizes ranging from 4 to 20 nm were obtained by adjusting the pH conditions and the presence of organic acids. The surface heterogeneity of these materials, at solid/gas and solid/liquid interfaces, was studied by combining various molecular probes. The low pressure quasi-equilibrium adsorption volumetry (N2/Ar) coupled with the DIS modeling approach and the flow adsorption microcalorimetry (NH3) have evidenced the various contributions of crystallographic faces and the effect of the crystallinity. These properties have also been analyzed using potentiometric titration in aqueous medium (H+/OH-), coupled with the TDIS procedure, to determine PZC and proton affinity distributions. Such a strategy has led to a complete study of the energetic and geometric surface properties of these nanomaterials

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Widmer, Johannes. "Charge transport and energy levels in organic semiconductors." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-154918.

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Organic semiconductors are a new key technology for large-area and flexible thin-film electronics. They are deposited as thin films (sub-nanometer to micrometer) on large-area substrates. The technologically most advanced applications are organic light emitting diodes (OLEDs) and organic photovoltaics (OPV). For the improvement of performance and efficiency, correct modeling of the electronic processes in the devices is essential. Reliable characterization and validation of the electronic properties of the materials is simultaneously required for the successful optimization of devices. Furthermore, understanding the relations between material structures and their key characteristics opens the path for innovative material and device design. In this thesis, two material characterization methods are developed, respectively refined and applied: a novel technique for measuring the charge carrier mobility μ and a way to determine the ionization energy IE or the electron affinity EA of an organic semiconductor. For the mobility measurements, a new evaluation approach for space-charge limited current (SCLC) measurements in single carrier devices is developed. It is based on a layer thickness variation of the material under investigation. In the \"potential mapping\" (POEM) approach, the voltage as a function of the device thickness V(d) at a given current density is shown to coincide with the spatial distribution of the electric potential V(x) in the thickest device. On this basis, the mobility is directly obtained as function of the electric field F and the charge carrier density n. The evaluation is model-free, i.e. a model for μ(F, n) to fit the measurement data is not required, and the measurement is independent of a possible injection barrier or potential drop at non-optimal contacts. The obtained μ(F, n) function describes the effective average mobility of free and trapped charge carriers. This approach realistically describes charge transport in energetically disordered materials, where a clear differentiation between trapped and free charges is impossible or arbitrary. The measurement of IE and EA is performed by characterizing solar cells at varying temperature T. In suitably designed devices based on a bulk heterojunction (BHJ), the open-circuit voltage Voc is a linear function of T with negative slope in the whole measured range down to 180K. The extrapolation to temperature zero V0 = Voc(T → 0K) is confirmed to equal the effective gap Egeff, i.e. the difference between the EA of the acceptor and the IE of the donor. The successive variation of different components of the devices and testing their influence on V0 verifies the relation V0 = Egeff. On this basis, the IE or EA of a material can be determined in a BHJ with a material where the complementary value is known. The measurement is applied to a number of material combinations, confirming, refining, and complementing previously reported values from ultraviolet photo electron spectroscopy (UPS) and inverse photo electron spectroscopy (IPES). These measurements are applied to small molecule organic semiconductors, including mixed layers. In blends of zinc-phthalocyanine (ZnPc) and C60, the hole mobility is found to be thermally and field activated, as well as increasing with charge density. Varying the mixing ratio, the hole mobility is found to increase with increasing ZnPc content, while the effective gap stays unchanged. A number of further materials and material blends are characterized with respect to hole and electron mobility and the effective gap, including highly diluted donor blends, which have been little investigated before. In all materials, a pronounced field activation of the mobility is observed. The results enable an improved detailed description of the working principle of organic solar cells and support the future design of highly efficient and optimized devices
Organische Halbleiter sind eine neue Schlüsseltechnologie für großflächige und flexible Dünnschichtelektronik. Sie werden als dünne Materialschichten (Sub-Nanometer bis Mikrometer) auf großflächige Substrate aufgebracht. Die technologisch am weitesten fortgeschrittenen Anwendungen sind organische Leuchtdioden (OLEDs) und organische Photovoltaik (OPV). Zur weiteren Steigerung von Leistungsfähigkeit und Effizienz ist die genaue Modellierung elektronischer Prozesse in den Bauteilen von grundlegender Bedeutung. Für die erfolgreiche Optimierung von Bauteilen ist eine zuverlässige Charakterisierung und Validierung der elektronischen Materialeigenschaften gleichermaßen erforderlich. Außerdem eröffnet das Verständnis der Zusammenhänge zwischen Materialstruktur und -eigenschaften einen Weg für innovative Material- und Bauteilentwicklung. Im Rahmen dieser Dissertation werden zwei Methoden für die Materialcharakterisierung entwickelt, verfeinert und angewandt: eine neuartige Methode zur Messung der Ladungsträgerbeweglichkeit μ und eine Möglichkeit zur Bestimmung der Ionisierungsenergie IE oder der Elektronenaffinität EA eines organischen Halbleiters. Für die Beweglichkeitsmessungen wird eine neue Auswertungsmethode für raumladungsbegrenzte Ströme (SCLC) in unipolaren Bauteilen entwickelt. Sie basiert auf einer Schichtdickenvariation des zu charakterisierenden Materials. In einem Ansatz zur räumlichen Abbildung des elektrischen Potentials (\"potential mapping\", POEM) wird gezeigt, dass das elektrische Potential als Funktion der Schichtdicke V(d) bei einer gegebenen Stromdichte dem räumlichen Verlauf des elektrischen Potentials V(x) im dicksten Bauteil entspricht. Daraus kann die Beweglichkeit als Funktion des elektrischen Felds F und der Ladungsträgerdichte n berechnet werden. Die Auswertung ist modellfrei, d.h. ein Modell zum Angleichen der Messdaten ist für die Berechnung von μ(F, n) nicht erforderlich. Die Messung ist außerdem unabhängig von einer möglichen Injektionsbarriere oder einer Potentialstufe an nicht-idealen Kontakten. Die gemessene Funktion μ(F, n) beschreibt die effektive durchschnittliche Beweglichkeit aller freien und in Fallenzuständen gefangenen Ladungsträger. Dieser Zugang beschreibt den Ladungstransport in energetisch ungeordneten Materialien realistisch, wo eine klare Unterscheidung zwischen freien und Fallenzuständen nicht möglich oder willkürlich ist. Die Messung von IE und EA wird mithilfe temperaturabhängiger Messungen an Solarzellen durchgeführt. In geeigneten Bauteilen mit einem Mischschicht-Heteroübergang (\"bulk heterojunction\" BHJ) ist die Leerlaufspannung Voc im gesamten Messbereich oberhalb 180K eine linear fallende Funktion der Temperatur T. Es kann bestätigt werden, dass die Extrapolation zum Temperaturnullpunkt V0 = Voc(T → 0K) mit der effektiven Energielücke Egeff , d.h. der Differenz zwischen EA des Akzeptor-Materials und IE des Donator-Materials, übereinstimmt. Die systematische schrittweise Variation einzelner Bestandteile der Solarzellen und die Überprüfung des Einflusses auf V0 bestätigen die Beziehung V0 = Egeff. Damit kann die IE oder EA eines Materials bestimmt werden, indem man es in einem BHJ mit einem Material kombiniert, dessen komplementärer Wert bekannt ist. Messungen per Ultraviolett-Photoelektronenspektroskopie (UPS) und inverser Photoelektronenspektroskopie (IPES) werden damit bestätigt, präzisiert und ergänzt. Die beiden entwickelten Messmethoden werden auf organische Halbleiter aus kleinen Molekülen einschließlich Mischschichten angewandt. In Mischschichten aus Zink-Phthalocyanin (ZnPc) und C60 wird eine Löcherbeweglichkeit gemessen, die sowohl thermisch als auch feld- und ladungsträgerdichteaktiviert ist. Wenn das Mischverhältnis variiert wird, steigt die Löcherbeweglichkeit mit zunehmendem ZnPc-Anteil, während die effektive Energielücke unverändert bleibt. Verschiedene weitere Materialien und Materialmischungen werden hinsichtlich Löcher- und Elektronenbeweglichkeit sowie ihrer Energielücke charakterisiert, einschließlich bisher wenig untersuchter hochverdünnter Donator-Systeme. In allen Materialien wird eine deutliche Feldaktivierung der Beweglichkeit beobachtet. Die Ergebnisse ermöglichen eine verbesserte Beschreibung der detaillierten Funktionsweise organischer Solarzellen und unterstützen die künftige Entwicklung hocheffizienter und optimierter Bauteile

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Žák, Jaromír. "Návrh a optimalizace senzorických systémů využívajících malovýkonových napájecích generátorů." Doctoral thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2015. http://www.nusl.cz/ntk/nusl-234527.

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Dissertation thesis is focused on using alternative energy sources called energy harvesting. This thesis offers a solution to problems with autonomous powering of sensor networks if primary power source recovery is impossible. In these cases, energy of the external power (e.g. temperature, light, motion) should be used. Proposed solution should be especially used in the field of medical applications (e.g. cochlear implants, pacemakers, insulin pumps). Long time monitoring of the personal health status is also possible when employing automated sensor systems. In this work, there is state of art review relating to the low power energy sources for an alternative powering of sensor systems. It was observed that existing systems are almost prepared for the implementation of energy harvesting power sources. The energy harvesting power sources have been developed by numerous researcher teams around the world, but there are only a few variants of power management circuits for effective energy gaining, storing and using. This area has a huge potential for the next research. The issues regarding to the distribution of gained energy are solved on the complex level in the thesis. For these purposes, a new simulation model of the whole system (fully implantable artificial cochlea) including its subcircuits was developed in the SPICE environment. It connects independent subcircuits into a single comprehensive model. Using this model, a few novel principles for energy distribution (e.g. Charge Push Through technique) was developed. In the near future, these techniques are also applicable to the design of versatile sensor systems.

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Heinrichová, Patricie. "Fotogenerace náboje v organických polovodičích." Doctoral thesis, Vysoké učení technické v Brně. Fakulta chemická, 2015. http://www.nusl.cz/ntk/nusl-233406.

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The interest in the detail knowledge about elementary electronic processes during photogeneration of charge carriers, which allow achieving higher efficiency of organic solar cells, grows with advent of the commercial organic solar cells production. The thesis is focused on study of photogeneration of charge carriers in organic semiconductors, especially in -conjugated polymer materials. First part of the thesis summarized state of the art in studies of photogeneration of charge carriers in polymer solar cells. Subsequent experimental and results part are focused on study of polymeric solar cells prepared from electron donor polymers MDMO-PPV, Tg-PPV, PCDTBT and PCBTDPP and electron acceptor derivates of fullerenes PC60BM and PC70BM. Results of the thesis are divided in tree main parts: 1) study of charge transfer between electron donor and electron acceptor materials by optical methods, 2) study of charge transfer between electron donor and electron acceptor materials by optoelectrical methods and 3) development of organic solar cells on flexible substrates. The last part is focused largely on deposition methods of active materials thin layer.

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Rentenier, Arnaud. "Fragmentation de la molécule C60 par impact d'ions légers étudiée en multicorrélation, sections efficaces, spectroscopie d'électrons." Toulouse 3, 2004. http://www.theses.fr/2004TOU30043.

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Cette thèse présente une étude quantitative des modes de fragmentation du fullerène C60 en collision avec des ions légers (Hn=1,2,3+ , Heq=1,2+) dans le domaine de vitesse 0,1 - 2,3 u. A. . La technique de multicorrélation (ions, électrons, énergie des électrons) employée a permis de dégager certaines dépendances et propriétés des mécanismes de fragmentation (sections efficaces, spectroscopie d'électrons, distributions de taille, énergies cinétiques des fragments, tracé de Campi, énergies d'activation). L'énergie déposée s'est ainsi révélée comme un paramètre important. Les sections efficaces ont été mesurées pour la première fois sur l'ensemble des processus collisionnels. L'ionisation et la capture ne dépendent que de la vitesse de collision. Une loi d'échelle avec l'énergie déposée a été observée pour les sections efficaces de multifragmentation. L'énergie déposée est aussi apparue comme le paramètre principal dans l'évolution des distributions de taille des fragments chargés émis. La spectroscopie des électrons (inédite sur un agrégat), réalisée à un angle d'émission de 35ʿ, a montré des spectres piqués à des énergies d'électron importantes (de 5 à 20 eV). .
A quantitative study of the C60 fullerene fragmentation in collision with light ions (Hn=1,2,3+, Heq=1,2+, in the velocity range 0,1 - 2,3 u. A. ) is presented. The multicorrelation developed between fragment ions and electrons with well defined energy, has enlightened some of the dependences and properties of fragmentation mechanisms (cross sections, electron spectroscopy, size distributions, kinetic energy of fragment ions, Campi's scatter plot, activation energies). The deposited energy hence appeared as an important parameter. Cross sections have been measured, for the first time, for all the collisionnal processes. Ionisation and capture only depends on the collision velocity. On the other hand, scaling laws with the deposited energy have been observed for the cross sections of multifragmentation, which depends on the collision energy and the nature of the projectile. The deposited energy has also been found as an essential parameter to understand the evolution of the charged fragment size distributions. .

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GOUTSOU, PERRAKI VASSILIKI. "Contribution a l'etude des cellules solaires epitaxiees sur si metallurgique." Paris 7, 1988. http://www.theses.fr/1988PA077138.

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Des photopiles p**(+)pn**(+) ont ete fabriquees par depot epitaxique d'une couche mince de si ultrapur sur un substrat sommairement purifie (umg) p**(+), puis formation de la couche n**(+), des contacts metalliques et de la couche antireflet par serigraphie. Mesures de la longueur de diffusion ln (methode lbic) et de la reponse spectrale des cellules

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Gaubert, Jean. "Contribution à l'étude des thyristors G. T. O. Symétriques : étude physique du mécanisme d'ouverture; relations entre performances et paramétres de structure." Toulouse, INSA, 1988. http://www.theses.fr/1988ISAT0013.

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Le mémoire est consacré à l'étude de l'ouverture des thyristors G. T. O. (gate-turn-off) symétriques. On prèsente d'abord un modèle numérique de l'ouverture des thyristors g. T. O. Qui rend compte de l'influence des paramètres de structure du composant ainsi que des interactions entre le composant et son environnement électrique. On utilise ensuite ce modèle pour analyser le mécanisme d'ouverture g. T. O. Et on évalue les performances de l'ouverture (pertes d'énergie dans le composant et temps de saturation). Enfin, on étudie l'influence des paramètres structuraux du composant (profil de diffusion et durée de vie des porteurs) toujours a l'aide du modèle, sur les performances d'ouverture

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Hérault, Joël. "Etude experimentale du ralentissement d'ions lourds de 20 a 100 mev par nucleon dans la matiere." Toulouse 3, 1988. http://www.theses.fr/1988TOU30075.

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Etude experimentale a l'aide d'ions lourds de l'accelerateur ganil sur le spectrometre lise (analyse en energie et en angle) pour determiner le pouvoir d'arret de 11 cibles gazeuses avec une incertitude de plus ou moins 3%. Mise en evidence d'une disparition de la difference entre pouvoirs d'arret des materiaux solides et gazeux lorsque la charge de l'ion tend vers son numero atomique. Analyse des distributions en energies pour de nombreux ions (de l'oxygene au molybdene) et analyse de la distribution angulaire dans des cibles solides et gazeuses. Comparaison des donnees experimentales aux calculs quantiques et classiques

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15

Bensitel, Abdeslam. "Spectroscopie des ions de recul d'argon produits par impact d'ions lourds dans le domaine 90-850a." Caen, 1988. http://www.theses.fr/1988CAEN2003.

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Identification de 417 raies de ar i a ar ix et de nouvelles raies de ar vi a ar vii dans le domaine 90-850 a obtenues par impact d'ions lourds d'energie inferieur au mev/nucleon. Obtention de differents types de spectres suivant le fonctionnement du faisceau: 1) en continu, spectre total a 2 dimensions (intensite, longueur d'onde) correspondant a l'emission prompte, 2) en pulse, spectre a 3 dimensions (intensite, temps, longueur d'onde) associe a l'emission retardee. Mise en evidence de phenomenes de capture electronique par collisions secondaires entre ions de recul et ar neutre, conformement aux previsions du modele classique de la barriere de potentiel

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CHEHIMI, MOHAMED-MEHDI. "Applications de l'esca a l'analyse de materiaux organiques : etude de quelques merocyanines." Paris 7, 1988. http://www.theses.fr/1988PA077218.

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Examen des possibilites offertes par l'esca pour l'etude des polarites des liaisons, la distribution des cgarges et les transferts de charge intramoleculaires dans les composes organiques. Etude des correlations energie de liaison - charge atomique afin d'estimer les charges portees par les heteroatomes des merocyanines etudiees. Etude des problemes poses par l'analyse esca des composes organiques et des effets de la polarisation electrique du porte-echantillon

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Suraud, Marie-Gabrielle. "Etude par spectrométrie X (10 [angström] [inférieur ou égal à] [lamda] [inférieur ou égal à] 100 [angström]) de l'échange de charge lors de collision à basse énergie, entre un ion multichargé et une cible neutre." Grenoble 1, 1988. http://www.theses.fr/1988GRE10038.

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Mesures des valeurs absolues des sections efficaces d'emission de rayons x, dont on deduit les valeurs absolues des sections efficaces de capture, pour les systemes c**(6+)-he,h::(2), n**(7+)-he,h::(2), o**(8+)-he,h::(c). Pour les projectiles a 2 electrons dans l'etat metastable 1s2s **(3)s, l'echange de charge peut s'accompagner de l'excitation de l'electron "2s" de l'ion incident vers des etats 1s2pnl **(3)p avec une probabilite variant suivant le systeme de collision, l'echange de charge simple restant preponderant dans tous les cas

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18

Rossi, Giuseppe Germano. "Etude de la réponse au rayonnement X entre 10KeV-100KeV des détecteurs à micro-pistes de germanium avec résolution spatiale et en énergie." Université Joseph Fourier (Grenoble), 1997. http://www.theses.fr/1997GRE10089.

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Dans le cadre d'un developpement d'un detecteur avec resolution spatiale et en energie pour comptage de photons dans des experiences de diffusion compton, nous avons etudie, au sein de l'esrf-grenoble, les performances de deux capteurs de germanium a micro-pistes. Ces deux detecteurs, issus de deux differentes technologies de fabrication, ont une resolution en energie associee a une resolution spatiale correspondante a leur pas de pistes de 200m. Nous avons valide l'utilisation d'une nouvelle plaquette multicouches connectante a tres haute densite les pistes du capteur meme, refroidi a l'azote liquide dans son cryostat, a l'electronique de lecture situee au plus proche a temperature ambiante. La resolution en position ainsi que la reponse en energie ont ete experimentalement caracterisees en balayant le detecteur avec un faisceau ponctuel monochromatique de lumiere de synchrotron de largeur 15m. Le systeme d'acquisition des donnees est base sur la mesure en coincidence de la reponse des pistes du capteur. A des energies plus basses que 15kev, nous trouvons que la region d'isolation entre deux pistes voisines est une source de piegeage de charge. Nous observons le phenomene de division de charge entre deux pistes a partir de 30kev. Cet effet, que nous lions au processus de diffusion des porteurs dans le volume du semi-conducteur, reduit considerablement la qualite des spectres d'energie ainsi que la resolution spatiale du capteur. Toutefois, apres traitement par un algorithme qui corrige la division de charge des donnees brutes tout en utilisant l'information des signaux mesures en coincidence, le phenomene de division dans les spectres est completement supprime. Nous avons mis au point a partir du code egs4, un programme de simulation de la reponse en energie comprenant le processus de diffusion des charges dans le volume du capteur. Les spectres en energie ainsi calcules reproduisent remarquablement les donnees experimentales et confirment le role critique de la diffusion de la charge dans la reponse des capteurs a micro-pistes. La conclusion de ce travail est que les detecteurs a micro-pistes de germanium fonctionnent dans la region d'energie 30-100kev avec une resolution en energie et position proche des limites physiques imposes par le processus d'absorption des photons et la diffusion des charges mobiles.

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Foster, Gillian Joanne. "Ethylene Supply in a Fluid Context: Implications of Shale Gas and Climate Change." MDPI AG, 2018. http://epub.wu.ac.at/6803/1/energies%2D11%2D02967.pdf.

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The recent advent of shale gas in the U.S. has redefined the economics of ethylene manufacturing globally, causing a shift towards low-cost U.S. production due to natural gas feedstock, while reinforcing the industry's reliance on fossil fuels. At the same time, the global climate change crisis compels a transition to a low-carbon economy. These two influencing factors are complex, contested, and uncertain. This paper projects the United States' (U.S.) future ethylene supply in the context of two megatrends: the natural gas surge and global climate change. The analysis models the future U.S. supply of ethylene in 2050 based on plausible socio-economic scenarios in response to climate change mitigation and adaptation pathways as well as a range of natural gas feedstock prices. This Vector Error Correction Model explores the relationships between these variables. The results show that ethylene supply increased in nearly all modeled scenarios. A combination of lower population growth, lower consumption, and higher natural gas prices reduced ethylene supply by 2050. In most cases, forecasted CO2 emissions from ethylene production rose. This is the first study to project future ethylene supply to go beyond the price of feedstocks and include socio-economic variables relevant to climate change mitigation and adaptation.

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Dossou, Dossouvi. "Fatigue thermique d'un polycarbonate : modèle de prédiction de durée de vie d'éprouvettes entaillées." Vandoeuvre-les-Nancy, INPL, 1996. http://www.theses.fr/1996INPL135N.

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Le polycarbonate est de plus en plus utilisé en ingénierie à cause de ses bonnes propriétés mécaniques. Il n'existe pas de procédure de dimensionnement bien établie pour tenir compte de la présence d'une concentration locale de déformation ou de contrainte dans une structure soumise à un chargement cyclique. Nous proposons un modèle de prévision de la durée de vie d'éprouvettes entaillées d'un polycarbonate en fatigue thermique. Le banc d'essai de fatigue thermique conçu est constitué d'un bâti assurant le maintien de l'éprouvette, d'un système de chauffage et de refroidissement, d'une unité de mesure et de régulation de la température, d'un système extensometrique ainsi que d'une unité informatique permettant la réalisation des cycles thermiques et l'asservissement précis des équipements. Des essais en traction isotherme sont réalisés pour déterminer les lois de comportement de notre polycarbonate dans l'intervalle de température des cycles thermiques. Les essais de cyclage thermique sur des éprouvettes lisses permettent de déterminer les lois de fatigue du matériau en terme d'énergie de déformation dissipée. L’analyse par la méthode des éléments finis permet de déterminer les coefficients de concentration de contrainte et la densité d'énergie de déformation dissipée en fond d'entaille. Notre modèle est obtenu en combinant la loi de fatigue du matériau et la loi d'évolution de la densité d'énergie de déformation dissipée en fond d'entaille en fonction du coefficient de concentration de contrainte. Ce modèle simple peut être utilisé pour déterminer la résistance à la fatigue d'autres matériaux et sous différents modes de sollicitation

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Subtil, Lacerda Juliana. "Low-carbon innovation: Renewable energy drivers and policies." Doctoral thesis, Universitat Autònoma de Barcelona, 2016. http://hdl.handle.net/10803/399892.

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El desarrollo de la innovación baja en carbono es necesario para generar energía suficiente y, al mismo tiempo, reducir las emisiones de gases de efecto invernadero de manera suficientemente rápida para evitar un cambio climático extremo. Esto hace con que sea fundamental el entendimiento de los factores capaces de acelerar el desarrollo y la difusión de la innovación baja en carbono. La innovación baja en carbono en el sector energético involucra diversos desafíos en función de la especificidad de sus características y dinámica, razón por la hay renovado interés en su investigación. Esta tesis doctoral reúne una serie de cinco artículos científicos que buscan explorar tópicos emergentes en torno a particular dinámica de la innovación baja en carbono, a saber: la formación de mercados líder, la diversidad tecnológica, la trayectoria tecnológica, estrategias de obtención de conocimiento, e impacto en la reducción de emisiones de gases de efecto invernadero. El primer artículo presenta una extensión del marco de referencia para análisis de mercados líder donde son adicionalmente considerados los factores referentes a la cadena de suministro y a políticas tecnológicas. Con base en la comparación del desarrollo de mercados líder en la industria eólica de Alemania, China, y Estados Unidos, este estudio demuestra el papel de los contextos de negocios y de las políticas de suporte a la innovación baja en carbono específicos de cada país. El segundo artículo explora el papel de la diversidad en el desarrollo de la innovación baja en carbono. Con base en el caso de la industria de energía fotovoltaica, nueve indicadores de diversidad tecnológica son aplicados para mapear la tendencia en la industria y su impacto en el desarrollo de nuevas innovaciones. El tercero artículo investiga la relación entre la evolución del conocimiento científico y la innovación baja en carbono en turbinas eólicas. Basándose en una nueva modelo para el análisis de citaciones, este artículo presenta nueva evidencia empírica de la relación entre desarrollo de conocimiento científico y la innovación baja en carbono. El cuarto artículo discute los resultados de una encuesta original realizada con organizaciones de investigación para analizar el impacto de diferentes estrategias de obtención de conocimiento en la innovación baja en carbono. Con base en la comparación de la investigación en energía solar y eólica, este estudio demuestra la importancia de políticas direccionadas a tecnologías específicas. Finalmente, el quinto artículo explora de que forma la rápida difusión de innovaciones bajas en carbono puede afectar su efecto en términos de reducciones de emisiones de gases de efecto invernadero. Analizando el caso de la energía eólica, este estudio demuestra el desequilibrio entre capacidad instalada y efectiva producción de energía eólica en cuatro países líderes en capacidad de generación eólica, a saber: Alemania, China, España y Estados Unidos. En resumen, esta tesis combina diferentes perspectivas de economía evolucionaria, ambiental y ecológica con estudios de innovación y clima para investigar las particular dinámica de innovación baja en carbono. Al estudiar los casos de las energías solar y eólica, esta tesis ofrece datos empíricos originales e ilustra nuevas posibilidades de suporte a la innovación baja en carbono.
Low-carbon innovation is required to match energy supply with GHG emissions reductions at a quick enough pace to avoid dangerous climate change. This calls for a deeper understanding of low-carbon innovation to explore factors capable of speeding up its development and diffusion. Low-carbon innovation in the energy sector involves a number of challenges due to its particular characteristics and dynamics which have renewed the interest in exploring its drivers. This doctoral dissertation combines a series of five research papers which address emerging issues regarding the particular dynamics of low-carbon innovation, namely: lead markets formation, technological diversity, technological trajectory, knowledge sourcing strategies and impact on GHG emissions reduction. In the first research paper, an extension of the lead market framework is developed to include supply side factors and technology policy issues. By comparing the development of lead markets in the wind power industry in China, Germany and the USA, this study shows the role of countries’ specific business contexts and policy responses on low-carbon innovation. The second study is dedicated to explore the role of diversity in low-carbon innovations. By looking at the solar photovoltaic (PV) industry, nine indicators of technological diversity are applied to map diversity trends in the industry and its impact on further innovation. Subsequently, the third research paper links scientific knowledge evolution and low-carbon innovation in wind turbines. Based on a novel approach to citation analysis, this study offers original evidence on this relationship. The fourth article is based on an original survey among research organisations to analyse the impact of distinct strategies of external knowledge sourcing on low-carbon innovation. By comparing research on solar and wind power, this study depicts the importance of technology-specific policies. The fifth and final study explores how fast deployment of low-carbon innovation can affect its potential of GHG emissions reduction. Considering the case of wind power, it addresses the mismatch between installed capacity and actual wind power output in four of the leading countries in terms of generation capacity, namely: China, the United States, Germany and Spain. In summary, this dissertation combines different perspectives from evolutionary, environmental and ecological economics with innovation and climate studies to explore the particular dynamics of low-carbon innovation. By looking at the cases of solar and wind power, this dissertation builds up original evidence and sheds new light into the possibilities of fostering innovation in low-carbon technologies.

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Kriel, Barend Jacobus. "A critical review of the consideration of energy alternatives in environmental impact assessment (EIA) / B. Kriel." Thesis, North-West University, 2010. http://hdl.handle.net/10394/4376.

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Climate change, as well as the recent energy crisis in South Africa, has placed renewed emphasis on the need to consider alternative energy options for future developments. EIA can and should play an important role in ensuring that energy alternatives are considered in developmental decision making. The need to consider energy alternatives has already been highlighted as EIA good practice in various guidelines, as well as being explicitly required in relevant application forms. The purpose of this research was twofold. Firstly, to determine the extent to which energy alternatives were considered in EIAs for Metropolitan developments. Secondly, to identify the barriers towards improving the uptake and consideration of energy alternatives by environmental assessment practitioners, environmental authorities and developers. The results show that the consideration of energy alternatives is almost non-existent with very few cases of best practice. The barriers towards introduction of energy alternatives seem to be related to a lack of information and knowledge, institutional resistance to change, as well as general expediency.
Thesis (M. Environmental Science)--North-West University, Potchefstroom Campus, 2010.

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Carvalho, Pedro Miguel Lavareda. "Zero energy. A energia solar como veículo para a sustentabilidade e rentabilidade de uma exploração agricola." Master's thesis, ISA, 2010. http://hdl.handle.net/10400.5/3361.

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Mestrado em Engenharia do Ambiente - Tecnologias Ambientais - Instituto Superior de Agronomia
In a world where the problems and concerns over the environment are growing, mainly associated to the GHG emissions, taking more sustainable behaviors it’s imperative in all business sectors. Throughout its history, agriculture has become technologically modern in order to be able to meet the food needs of an increasingly large and consumerist population, and at the same time, staying profitable in an increasingly competitive market. This trend of technological change has also occurred in renewable energy, particularly solar energy. This work aimed to demonstrate the opportunity, necessity and importance of adopting an agriculture vision, which promotes a more sustainable development through the implementation of several technologies for harnessing solar energy on a farm, increasing its cost-effectiveness too. The adopted approach consisted on energy consumption analysis (electricity and heat) of a prototype farm, based on real data from two types of farming (livestock and horticulture), which were subsequently implemented several technologies for harnessing solar energy (solar photovoltaic, solar thermal and solar passive), making the operation environmentally more sustainable by reducing the use and the dependence of fossil fuels, and economically more viable, with reduced consumption and direct sales of energy produced to the electric grid. Based on the collected information on the ground and after construction of the prototype, where some energy consumption process were added, aimed to include greater representation at national level, were evaluated various possibilities of using solar energy in the prototype, implementation, cost / benefit and environmental sustainability, using tree international computational software’s (PVsyst, Sunny Design and Wica). It was concluded that the Solar Energy and Agriculture could and should have a Convergent Future!

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Unal, Ridvan. "Energy and charge state dependences of transfer ionization to single capture ratio for fast multiply charged ions on Helium /." Search for this dissertation online, 2001. http://wwwlib.umi.com/cr/ksu/main.

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Chomette, André. "Proprietes electroniques et optiques des superreseaux gaas/gaalas de petites periodes." Paris 6, 1988. http://www.theses.fr/1988PA066146.

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Machado, Jorge Felizardo Dias Cunha. "High precision tests of QED : measurement of the alpha-particle and helion rms charge radius and the transition energies in highly-charged ions." Thesis, Sorbonne université, 2018. http://www.theses.fr/2018SORUS016/document.

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Ce travail vise à contribuer à l’amélioration de notre connaissance de l’électrodynamique quantique des états liés, par des mesures de haute précision dans des états exotiques de la matière. Bien que notre connaissance de l’électrodynamique quantique des états liés et du problème relativiste à plusieurs corps aient fait des progrès importants ces dernières années, il reste des questions fondamentales dont la résolution nécessite d’augmenter le nombre et la précision des tests expérimentaux. La première partie de ce travail a été réalisée dans le cadre de l’expérience récente sur les ions muoniques d’hélium (μ4He+ et μ3He+) conduite par la collaboration CREMA. Cette expérience vise à fournir de nouvelles valeurs précises pour les rayons de charge moyens des noyaux des isotopes stables de l’hélium. Ces valeurs sont extraites de la mesure du déplacement de Lamb, c’est-à-dire, de la mesure de la différence d’énergie entre les États 2S − 2P. Une mesure des énergies de transition d’une précision d’au moins 50 ppm, permet de déterminer les rayons de charge des noyaux des isotopes d’hélium avec une incertitude de 0,03%, dix fois plus précise que les résultats précédents obtenus à partir de la diffusion d’électrons. La deuxième partie de ce travail a été de réaliser des mesures de haute précision de transitions de rayons X dans des ions fortement chargés, à l’aide d’un spectromètre à double cristal plan. Ces ions étaient produits dans le plasma d’une source d’ions de type ECRIS (electron-cyclotron resonance ion source). Le spectromètre utilisé est non seulement capable de fournir des mesures de haute précision, mais aussi des mesures sans référence à des énergies de transition théorique ou expérimentales. Quatre énergies de transition de n = 2 → n = 1 ont été mesurées pour des ions d’argon de trois états de charge différents, héliumoïde, lithiumoïde et berylliumoïde, avec une précision meilleure que 3 ppm. La largeur naturelle de chaque raie a également été obtenue expérimentalement. Les résultats trouvés sont en excellent accord avec les calculs théoriques les plus récents
This work aims to provide insight on Bound-State Quantum-Electrodynamics (BSQED) by experimental fundamentals high-precision tests in exotic states of matter. Although BSQED and the relativistic many-body problem have been undergoing important progress, there are still some issues that require the increase of the number and accuracy of experimental fundamental tests. The first part of this work was done within the framework of the recent experiment in muonic helium ions (μ4He+ and μ3He+) by the CREMA collaboration. This experiment, aims to provide new accurate values for the root-mean-square (rms) charge radii of the helium isotopes nuclei that are extracted from the measurement of the Lamb Shift, i.e., the measurement of the energy difference between the 2S − 2P states. With the goal of measuring the transition energies with an accuracy of at least 50 ppm, the rms charge radii of the helium isotopes will be determined with an uncertainty of 0.03%, a factor of ten more precise than previous results obtained from electron scattering. The second part of this work aims the high-precision measurement of x-ray transitions in Highly-Charged Ions (HCI) using a Double-Crystal Spectrometer (DCS). These ions were produced in the plasma of an Electron-Cyclotron Resonance Ion Source (ECRIS). This kind of spectrometer is able not only to provide high-precision measurements but also reference-free measurements, without reference to any theoretical or experimental energy. Four transitions energies from n = 2 → n = 1 have been measured in an argon plasma in three different charge states, He-, Be- and Li-like, with an accuracy of better than 3 ppm. Besides the energies, the natural width of each transition has also been experimentally obtained. The obtained results are in excellent agreement with the most recent theoretical calculations

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Machado, Jorge Felizardo Dias Cunha. "High precision tests of QED Measurement of the alpha-particle and helion rms charge radius and the transition energies in highly-charged ions." Doctoral thesis, Sorbonne université, 2018. http://hdl.handle.net/10362/33710.

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Ce travail vise à contribuer à l’amélioration de notre connaissance de l’électrodynamique quantique des états liés, par des mesures de haute précision dans des états exotiques de la matière. Bien que notre connaissance de l’électrodynamique quantique des états liés et du problème relativiste à plusieurs corps aient fait des progrès importants ces dernières années, il reste des questions fondamentales dont la résolution nécessite d’augmenter le nombre et la précision des tests expérimentaux. La première partie de ce travail a été réalisée dans le cadre de l’expérience récente sur les ions muoniques d’hélium (μ4He+ et μ3He+) conduite par la collaboration CREMA. Cette expérience vise à fournir de nouvelles valeurs précises pour les rayons de charge moyens des noyaux des isotopes stables de l’hélium. Ces valeurs sont extraites de la mesure du déplacement de Lamb, c’est-à-dire, de la mesure de la différence d’énergie entre les États 2S − 2P. Une mesure des énergies de transition d’une précision d’au moins 50 ppm, permet de déterminer les rayons de charge des noyaux des isotopes d’hélium avec une incertitude de 0,03%, dix fois plus précise que les résultats précédents obtenus à partir de la diffusion d’électrons. La deuxième partie de ce travail a été de réaliser des mesures de haute précision de transitions de rayons X dans des ions fortement chargés, à l’aide d’un spectromètre à double cristal plan. Ces ions étaient produits dans le plasma d’une source d’ions de type ECRIS (electron-cyclotron resonance ion source). Le spectromètre utilisé est non seulement capable de fournir des mesures de haute précision, mais aussi des mesures sans référence à des énergies de transition théorique ou expérimentales. Quatre énergies de transition de n = 2 → n = 1 ont été mesurées pour des ions d’argon de trois états de charge différents, héliumoïde, lithiumoïde et berylliumoïde, avec une précision meilleure que 3 ppm. La largeur naturelle de chaque raie a également été obtenue expérimentalement. Les résultats trouvés sont en excellent accord avec les calculs théoriques les plus récents
This work aims to provide insight on Bound-State Quantum-Electrodynamics (BSQED) by experimental fundamentals high-precision tests in exotic states of matter. Although BSQED and the relativistic many-body problem have been undergoing important progress, there are still some issues that require the increase of the number and accuracy of experimental fundamental tests. The first part of this work was done within the framework of the recent experiment in muonic helium ions (μ4He+ and μ3He+) by the CREMA collaboration. This experiment, aims to provide new accurate values for the root-mean-square (rms) charge radii of the helium isotopes nuclei that are extracted from the measurement of the Lamb Shift, i.e., the measurement of the energy difference between the 2S − 2P states. With the goal of measuring the transition energies with an accuracy of at least 50 ppm, the rms charge radii of the helium isotopes will be determined with an uncertainty of 0.03%, a factor of ten more precise than previous results obtained from electron scattering. The second part of this work aims the high-precision measurement of x-ray transitions in Highly-Charged Ions (HCI) using a Double-Crystal Spectrometer (DCS). These ions were produced in the plasma of an Electron-Cyclotron Resonance Ion Source (ECRIS). This kind of spectrometer is able not only to provide high-precision measurements but also reference-free measurements, without reference to any theoretical or experimental energy. Four transitions energies from n = 2 → n = 1 have been measured in an argon plasma in three different charge states, He-, Be- and Li-like, with an accuracy of better than 3 ppm. Besides the energies, the natural width of each transition has also been experimentally obtained. The obtained results are in excellent agreement with the most recent theoretical calculations

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28

Kimber, Robin. "Charge and energy transport in organic semiconductors." Thesis, University of Bath, 2011. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.541527.

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This work describes the application of Kinetic Monte Carlo (KMC) modelling technique to organic photovoltaic (OPV) devices. Such devices are an exciting and relatively new form of photovoltaic (PV) technology, which can help bring solar power to the mass market using low energy processing methods, and materials that are cheap, and have several novel characteristics, such as being lightweight, flexible, and potentially even translucent. The modelling technique and many of the results found here are also applicable to other organic devices, such as organic light-emitting displays (OLEDs), as the underlying device physics is very similar. Following an introduction and discussions on the theoretical basis of the work and its computational implementation, the work described in the thesis falls into three main sections: Firstly, an evaluation is performed as to the accuracy of the First Reaction Method (FRM), a means of reducing the computational complexity of KMC simulations. Although this method is widely used, its accuracy when used to model OPV devices has never been satisfactorily evaluated, leading it to be questioned by some authors. Hence, its accuracy under a range of scenarios relevant for OPV simulations was tested and quantified. The findings presented here confirm its validity within the field and disorder ranges that are applicable to OPV device operation, and also give some insight into low-field geminate separation dynamics. Secondly, the KMC methodology, with the FRM approximation, is applied to the investigation of the role of device morphology in determining OPV efficiency. Morphology optimisation has frequently been identified as being key to future device design, and the KMC methodology is unique in its ability to examine this. Furthermore, as the popularity of using self-assembled bicontinuous nanostructures in OPVs grows, it is useful to evaluate their potential impact on OPV efficiency, using the insight gained from investigating morphology in general. Among the main conclusions reached from this work, it was determined that one of the key limiting factors in the efficiency of devices is the angle of the heterojunctions to the field, which is a feature of the device morphology. It was also found that, because of this, bicontinuous structures are unlikely to greatly improve OPV efficiency. Thirdly, modelling was performed in an attempt to reproduce the quantitative experimental characteristics of PFB:F8BT devices. This was achieved through first modelling individual charge mobility in the two polymers in question, and quantifying the effects of different forms of disorder. Having found disorder descriptions that could reproduce the single carrier mobility of both PFB and F8BT, as deduced by Blakesley et. al. using drift-diffusion modelling, this disorder description was applied to single layer devices, in order to deduce the injection barrier. Finally, the disorder and injection barriers deduced were combined with optical modelling to reproduce full photovoltaic behaviour. This was generally found to be successful, and therefore potentially gives some real insight into the nature of polymer disorder, whilst also validating the KMC model used in this thesis. An additional implication of this work is that the KMC model can, in the future, be applied to experimental data which cannot be satisfactorily modelled using drift-diffusion simulations.

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Maltoni, Matteo. "Energy emission by moving charges." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2018. http://amslaurea.unibo.it/16347/.

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This paper analizes the power emitted by charges accelerated on general trajectories. The electric and magnetic field radiated are calculated in detail through the retarded potentials, and the non-relativistic, quasistatic and radiation regimes are treated. The radiated power is obtained through the calculation of the Poynting vector, and the two cases of linear and circular accelerators are analyzed. After this, the distribution in frequencies of this radiation is studied for a moving charge and a moving magnetic moment, and the intensity distribution in angles and frequencies is generalized to the case of a continuous set of charges in motion.

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Dowell, Marla L. (Marla Lorraine) 1965. "Pion single charge exchange in three body nuclei at intermediate energies." Thesis, Massachusetts Institute of Technology, 1994. http://hdl.handle.net/1721.1/26856.

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Kabutz, Rudolf T. "The (p, n) charge-exchange reaction on ⁹⁰Zr at intermediate energies." Master's thesis, University of Cape Town, 1992. http://hdl.handle.net/11427/17385.

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Bibliography: p. 67-69.
Using the Time-of-Flight facility at the National Accelerator Centre at Faure, the (p, n) charge-exchange reaction has been studied at intermediate energies of 120, 160 and 200 MeV, and at angles of 0°, 2° and 4°. In this work the data collected for the ⁹⁰Zr target will be presented. The influence on the data from slow neutrons due to previous pulses is discussed and the best manner of removing them from the spectra is recommended. It is shown how the background cosmic rays can be utilised to measure the intrinsic resolution of the detectors and to obtain an estimate of the neutron energy threshold. The differential cross-sections for the states corresponding to Fermi and Gamow-Teller transitions were extracted from the time spectra. The sum of the strength of all the discrete Gamow-Teller states was determined and compared to the Ikeda Sum Rule. It was found that only 50% of the sum could be accounted for in the discrete states. An overview of the theory that has been developed to extract Gamow-Teller strengths from the (p, n) cross-sections is given. Some of the theoretical models that have been used to describe the ⁹⁰Zr(p, n)⁹⁰ Nb reaction and account for the missing Gamow-Teller strength are briefly discussed.

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Beaudoin, Brian L. "Longitudinal space-charge waves induced by energy modulations." College Park, Md.: University of Maryland, 2008. http://hdl.handle.net/1903/8794.

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Thesis (M.S.) -- University of Maryland, College Park, 2008.
Thesis research directed by: Dept. of Electrical and Computer Engineering. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.

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Gillespie, Peter N. O. "Theory of charge transfer in solar energy materials." Thesis, University of Sheffield, 2018. http://etheses.whiterose.ac.uk/22771/.

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Strauss, Roelf du Toit. "Modelling of cosmic ray modulation in the heliosphere by stochastic processes / Roelf du Toit Strauss." Thesis, North-West University, 2013. http://hdl.handle.net/10394/10217.

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The transport of cosmic rays in the heliosphere is studied by making use of a newly developed modulation model. This model employes stochastic differential equations to numerically solve the relevant transport equation, making use of this approach’s numerical advantages as well as the opportunity to extract additional information regarding cosmic ray transport and the processes responsible for it. The propagation times and energy losses of galactic electrons and protons are calculated for different drift cycles. It is confirmed that protons and electrons lose the same amount of rigidity when they experience the same transport processes. These particles spend more time in the heliosphere, and also lose more energy, in the drift cycle where they drift towards Earth mainly along the heliospheric current sheet. The propagation times of galactic protons from the heliopause to Earth are calculated for increasing heliospheric tilt angles and it is found that current sheet drift becomes less effective with increasing solar activity. Comparing calculated propagation times of Jovian electrons with observations, the transport parameters are constrained to find that 50% of 6 MeV electrons measured at Earth are of Jovian origin. Charge-sign dependent modulation is modelled by simulating the proton to anti-proton ratio at Earth and comparing the results to recent PAMELA observations. A hybrid cosmic ray modulation model is constructed by coupling the numerical modulation model to the heliospheric environment as simulated by a magneto-hydrodynamic model. Using this model, it is shown that cosmic ray modulation persists beyond the heliopause. The level of modulation in this region is found to exhibit solar cycle related changes and, more importantly, is independent of the magnitude of the individual diffusion coefficients, but is rather determined by the ratio of parallel to perpendicular diffusion.
PhD (Space Physics), North-West University, Potchefstroom Campus, 2013

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Howarth, Nicholas A. A. "The political economy of technological change, energy and climate change." Thesis, University of Oxford, 2012. http://ora.ox.ac.uk/objects/uuid:96957dc1-2bc8-466f-8963-4a7edbc0569c.

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This thesis sets out to explore some of the key dimensions in the process of socio-technological change inherent in the shift to a low carbon economy. This is done in two parts, the first focusing on theory, the second, empirical case studies. Out of the diversity of interactions between actors, technologies, and policies surrounding this process, one key question emerges: can societies really shift the structure of their economies so fundamentally to achieve a low carbon future within a reasonable timeframe? Chapter One develops an integrated approach to economic and political change to interrogate this question. This synthesizes a review of literature (Part One) examining the role of technology within some of the main theories of economic change in the social sciences. Two broad paradigms are distinguished. First, a paradigm based around the notion of equilibrium, notably the standard welfare approach of neoclassical economics; and secondly, an evolutionary paradigm, which views the economy as a complex adaptive system – such as exemplified by theories of path dependency. This theoretical background provides a broad narrative to frame and inform Part Two of the thesis. First in Chapter Four, socio-technical change is investigated in the context of the diffusion of energy efficient lighting in Germany. This study investigates the relationships between human behaviour and attitudes, lamp technology and the evolving nature of institutions, to provide a framework with which to consider the contentious issue of individual freedom versus government control in the politics of change to lower-carbon emissions. In Chapter Five, the case for the creation of a market for CO2 pollution permits is developed. In making this case, the strengths and weaknesses of emissions trading are compared and contrasted with other policy instruments and the broader political economy of the various policy options discussed. Chapter 6 builds on this to examine the political economy of implementing an emissions trading scheme in Australia and the impact the Kyoto Protocol has had on domestic politics and GHG mitigation. Chapter Seven continues with the theme of building ‘a political ecology of the state’ by investigating the politics and economics of greenhouse gas mitigation in Russia. Finally, Chapter Eight recapitulates the aims, nature and conclusions of this research and draws out its implications for policy as well as mapping out some areas for further research. In particular, the need to bring a greater sense of politics back into the study of the economy is highlighted as a vital part of building a renewed, more sustainable economic paradigm in the wake of the financial crisis and, as a way of strengthening the connection between social values and market outcomes.

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Cunha, Kamyla Borges da. "Mecanismo de desenvolvimento limpo : evolução do instrumento e suas perspectivas." [s.n.], 2005. http://repositorio.unicamp.br/jspui/handle/REPOSIP/263871.

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Orientadores: Arnaldo Cesar Walter, Fernando C. Fernandes Rei
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica
Made available in DSpace on 2018-08-04T13:34:29Z (GMT). No. of bitstreams: 1 Cunha_KamylaBorgesda_M.pdf: 14666940 bytes, checksum: 2d702a4828f0282a65591987a5f20e80 (MD5) Previous issue date: 2005
Resumo: Neste trabalho, analisou-se o MDL, delineando-lhe o conceito, objetivos, princípios, procedimento de implantação e os critérios de elegibilidade; o delineamento da inserção do MDL no Brasil; e a investigação da potencialidade do MDL como ferramenta de obtenção de formas renováveis de energia, possibilitando a futura análise da efetividade desse instrumento como ferramenta de promoção de novos padrões de obtenção de energia. Foi realizada ampla revisão bibliográfica sobre o tema, a contemplar as bases científicas das mudanças climáticas, o processo de negociação, os objetivos e princípios da CQNUMC, o histórico e aspectos do Protocolo de Quioto; o funcionamento do regime jurídico-político instituído por esses tratados; o MDL, seus objetivos, estrutura, dinâmica e processo de certificação, enfocando-se, de forma crítica, os critérios de elegibilidade. Depois da contextualização do plano teórico do MDL, realizou-se uma revisão bibliográfica sobre a operacionalização do MDL no mercado de carbono, explicitando a teoria econômica subjacente aos mecanismos de flexibilização, assim como o funcionamento do mercado de carbono. Tomando como base a visão geral do MDL, procurou-se focar a inserção do MDL no Brasil, dando-se destaque aos aspectos relacionados ao setor de energia
Abstract: This study has as main objectives the anaIysis of CDM, expIaining its concept, objectives, principIes and procedures, eIigibiIity criteria; the investigation of CDM impIementation in BraziI; and the assessment of the potentiaI to use CDM as a tooI to incentive sustainabIe energy generation. In order to achieve these aims, it was made a bibliographic revision about scientific basis of climate change, intemationaI negotiation process, UNFCCC objectives and principIes, Kyoto Protocol main aspects; dynamics of the cIimate regime impIemented by these treaties; the CDM, its objectives, structure, dynamics and procedures and modalities, a criticaI assessment of its eligibility criteria and the CDM dynamics in the carbon market. After this, and taking into account the main aspects of this anaIysis, it was investigated CDM impIementation in BraziI, focusing the reIated energy aspects
Mestrado
Energia, Sociedade e Meio Ambiente
Mestre em Engenharia Mecânica

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37

SENCE, MARTINE. "Etude des proprietes optiques du seleniure de cadmium sous hautes intensites d'excitation lumineuse." Université Louis Pasteur (Strasbourg) (1971-2008), 1989. http://www.theses.fr/1989STR13021.

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Etude des caracteristiques du plasma electron-trou. Interpretation des courbes de gain optique obtenues par deux modeles theoriques. Etude des proprietes des biexcitons par melange degenere a quatre ondes et determination de leur energie de liaison (2 mev)

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38

Rambaud, Christophe. "Etude, par spectroscopie optique, de la délocalisation quantique de protons dans des cristaux d'acide benzoi͏̈que." Grenoble 1, 1989. http://www.theses.fr/1989GRE10103.

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Les transitions optiques des molecules de thioindigo dopant des cristaux d'acide benzoique, sont sensibles au transfert des protons par effet tunnel le long des liaisons hydrogene intradimeres de la matrice. Mesure dans le cas d'un acide carboxylique des niveaux d'energie des protons delocalises et de l'element de matrice d'effet tunnel. Sensibilite du systeme a transfert de protons aux contraintes internes et externes. Deduction des vitesses de relaxation des protons delocalises, comparaison avec des calculs theoriques indiquant l'importance des processus a plusieurs phonons dans cette relaxation. Utilisation de l'effet d'un champ electrique pour influencer la delocalisation des protons

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39

Veuillen, Jean-Yves. "Etude par spectroscopie Mössbauer et de photoémission en rayonnement ultraviolet des bronzes bleus de molybdène A(0. 3)MoO3 (A = K, Rb)." Grenoble 1, 1986. http://www.theses.fr/1986GRE10146.

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Le bronze bleu a::(0,3)moo::(3) (a = k, rb) est un metal quasi-unidimensionnel a temperature ambiante qui presente une transition isolant-metal de type peierls a 183k. Etude de la structure de bandes dans la direction metallique par photoemission angulaire. Mesure de l'energie de liaison et du vecteur de fermi. Evolution thermique de l'interaction onde de densite de charge-impuretes, au voisinage de 100k, etudiee par spectrometrie moessbauer

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40

Cakacaka, Akuila Labati [Verfasser], Marion [Akademischer Betreuer] Glaser, Marion [Gutachter] Glaser, and Matthias [Gutachter] Wolff. "Livelihood Vulnerability of Coastal Communities in Fiji and Solomon Islands to Changes in Reef Resource Availability and Climate Change / Akuila Labati Cakacaka ; Gutachter: Marion Glaser, Matthias Wolff ; Betreuer: Marion Glaser." Bremen : Staats- und Universitätsbibliothek Bremen, 2018. http://d-nb.info/1174669721/34.

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41

Tiezzi, Rafael de Oliveira 1981. "Impactos da variação pluviometricas associadas as mudanças climaticas sobre a geração de energia hidreletrica na Bacia do Alto Paranapanema." [s.n.], 2009. http://repositorio.unicamp.br/jspui/handle/REPOSIP/264172.

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Orientador: Andre Felipe Simões
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica
Made available in DSpace on 2018-08-14T07:29:47Z (GMT). No. of bitstreams: 1 Tiezzi_RafaeldeOliveira_M.pdf: 2575812 bytes, checksum: a2db99c9081c7277f3f8a969432ae890 (MD5) Previous issue date: 2009
Resumo: O presente trabalho foi motivado pelo grande foco que os governos, mídias, ONG's, empresas e a sociedade de uma forma geral, vêm dando à questão da mudança climática global. Neste sentido estima-se que até 2100, a temperatura média global pode elevar-se, na média, de 2ºC a mais de 4ºC (IPCC, 2007). O presente trabalho adota a linha de estudo voltada a análise dos impactos gerados pelas mudanças climáticas, ou ainda, previsão de impactos gerados pelas mudanças climáticas em um cenário futuro de curto e médio prazo. Desta forma o presente estudo visa estabelecer relações entre segurança energética e mudanças climáticas, porém tem como objeto de estudo principal uma região em escala micro, no caso a Bacia Hidrográfica do Alto Paranapanema, o que diferencia este trabalho dos demais realizados no Brasil até então. Foram analisadas as influências das mudanças climáticas sobre a capacidade de geração de energia hidrelétrica em duas de suas mais tradicionais formas de geração, quais sejam: Usinas Hidrelétricas de grande porte e Pequenas Centrais Hidrelétricas (PCHs) de pequeno porte. Foi feito um estudo hidrológico da Bacia onde foram associados os cenários futuros sobre as mudanças do clima, especificamente os cenários de anomalias pluviométricas, e a mudança na vazão. Tal associação foi realizada através do modelo matemático SMAP (Soil Moisture Accounting Procedure). A vazão, por sua vez, alterada pela influência climática foi simulada no modelo HidroLab resultando na geração de energia hidrelétrica. Os resultados apontam uma perda de capacidade de geração. Tais perdas podem ser atribuídas às anomalias negativas de chuva encontradas pela modelagem realizada por Hamada et. al. (2008) e sua direta influência na vazão dos rios, fator este fundamental na geração de energia hidráulica. Porém o que chama a atenção é a não-linearidade entre tais fatores de perda.
Abstract: This work was motivated by the major focus for governments, media, ONGs, businesses and society in general, have been giving the issue of global climate change. In this sense it is estimated that by 2100, the average global temperature may rise, to 2 º C for more than 4 º C (IPCC, 2007). This paper adopts the line of study focuses the analysis of the impacts generated by climate change or, estimates of impacts generated by climate change in a scenario of future in short and medium term. Thus this study aims to establish links between energy security and climate change, but has as main object of study a region in micro scale, in the Alto Paranapanema Watershed, which differentiates this study from other work carried out in Brazil until then. For this, was examined the influences of climate change on the ability to generate hydroelectric power in two of its most traditional forms generation, namely: large-scale hydroelectric and small hydroelectric plants exchangers (PCHs. Was made a study of the hydrological basin where they were associated with future scenarios on climate change, specifically the scenarios of rainfall anomalies, and the change in flow. This association was made through the mathematical model SMAP (Soil Moisture Accounting Procedure). The flow, in turn, influence the altered climate was simulated in the model HidroLab resulting in the generation of hydroelectric power. The results indicate a loss of generation capacity. Such losses can be attributed to negative anomalies of rainfall found by modeling performed by Hamada et. al. (2008) and its direct influence on the flow of rivers, this fundamental factor in the generation of hydropower. But what draws attention is the nonlinearity of such factors of loss.
Mestrado
Planejamento de Sistemas Energeticos
Mestre em Planejamento de Sistemas Energéticos

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42

Kumar, Navneet [Verfasser]. "Impacts of Climate change and Land use change on the Water resources of the Upper Kharun Catchment, Chhattisgarh, India / Navneet Kumar." Bonn : Universitäts- und Landesbibliothek Bonn, 2014. http://d-nb.info/1077268912/34.

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43

Hsieh, S. "Fragmentation mechanisms of doubly charged ions." Thesis, University of Oxford, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.284502.

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44

Onjira, Phoebe Pauline Ingado [Verfasser], and F. [Akademischer Betreuer] Nestmann. "Influence of Morphology, Climate Change and Landuse Change on Water Partitioning in Olifants River Basin / Phoebe Pauline Ingado Onjira ; Betreuer: F. Nestmann." Karlsruhe : KIT-Bibliothek, 2020. http://d-nb.info/121957788X/34.

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45

Onjira, Phoebe Pauline [Verfasser], and F. [Akademischer Betreuer] Nestmann. "Influence of Morphology, Climate Change and Landuse Change on Water Partitioning in Olifants River Basin / Phoebe Pauline Ingado Onjira ; Betreuer: F. Nestmann." Karlsruhe : KIT-Bibliothek, 2020. http://d-nb.info/121957788X/34.

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46

Roget, Fabien. "Définition, modélisation et validation expérimentale d’une capacité de stockage thermique par chaleur latente adaptée à une centrale thermodynamique solaire à basse température." Thesis, Toulon, 2012. http://www.theses.fr/2012TOUL0004/document.

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Ce travail est effectué dans le cadre d'une thèse Conventions Industrielles de Formation par la Recherche (CIFRE) entre l’entreprise Sophia Antipolis Énergie Développement (SAED) à Valbonne et l'Institut Matériaux Microélectronique Nanosciences de Provence (IM2NP) – CNRS – Université du Sud Toulon-Var.L’objectif de cette collaboration est l’évaluation du potentiel technico-économique de divers matériaux pour le stockage de l’énergie thermique par chaleur latente, adapté aux niveaux de température des capteurs solaires développés par SAED. En effet, le stockage de l’énergie est un des principaux verrous technologiques reconnus pour les procédés ayant recours à des énergies renouvelables intermittentes et en particulier pour les centrales héliothermodynamiques.Après une introduction sur le potentiel et l’intérêt des centrales solaires thermodynamiques à basse température, un bref état de l’art des principaux types de stockage de l’énergie est présenté. Le deuxième chapitre aborde plus en détail le principe du stockage thermique par chaleur latente et recense une centaine de matériaux sélectionnés dans la littérature pour leur changement de phase dans la gamme de température 70 - 140°C. Les critères de sélection retenus y sont exposés.Des analyses thermiques par calorimétrie différentielle à balayage sont effectuées de façon systématique sur les différents Matériaux à Changement de Phase (MCP) sélectionnés. Les résultats de ces mesures, présentés dans le chapitre III, caractérisent avec précision le comportement de ces matériaux au chauffage. La transformation au refroidissement est étudiée au moyen d’un dispositif conçu spécifiquement pour représenter au mieux les conditions imposées dans une enceinte industrielle. Cette étude, présentée dans le chapitre IV, permet d’affiner la sélection des MCP pour ne garder que ceux dont la réversibilité du changement d’état est compatible avec une utilisation industrielle en tant que milieu de stockage de l’énergie thermique. Les chapitres V et VI permettent d’étudier plus en détails les spécificités de deux types de MCP que sont les polyols et les mélanges eutectiques de nitrates.Le dernier chapitre est consacré à la modélisation des échanges thermiques au sein d’une cuve de stockage contenant un MCP encapsulé. L’objectif est de disposer d’un outil de prédiction des performances d’une unité de stockage par chaleur latente, afin d’analyser l’influence des différentes solutions envisagées sur le productible d’une centrale thermodynamique solaire et leur impact sur le coût du kWh électrique produit
This work of thesis is done within the framework of industrial agreements research training, between the company Sophia Antipolis Energie Développement (SAED) in Valbonne, and the Institut Matériaux Microélectronique Nanosciences de Provence (IM2NP) – CNRS – University Sud Toulon-Var.The aim of this collaboration is to investigate the technical and economic potential of various materials for thermal energy storage by latent heat, suitable for temperature levels of the solar collectors developed by SAED. Indeed, energy storage is a major technological barrier to the process resorting to intermittent renewable energies and especially for thermodynamic solar power plants.After an introduction on the potential and interest of solar power plants working at low temperature, a brief state of art of the main types of energy storage is presented. The second chapter addresses in detail the principle of thermal storage by latent heat and identifies a hundred of selected materials from the literature for phase change in the temperature range 343 - 413 K. The selection criteria are exposed.Thermal analyses by differential scanning calorimetry are carried out systematically on the various selected Phase Change Materials (PCMs). The results of these measurements, presented in chapter III, accurately characterize the material behavior when heated. The transformation on cooling is studied using a device specifically designed in order to be more representative of conditions found in an industrial enclosure. This study, presented in chapter IV, allows refining the selection of PCMs retaining only those whose phase change reversibility is compatible with an industrial use as medium for thermal energy storage. Chapters V and VI are used to study in further detail the specifics of two types of MCP, respectively polyols and eutectic mixtures of nitrates.Final chapter deals with the modeling of heat transfer into a storage tank containing encapsulated PCM. The aim is to provide a tool for predicting the performance of a latent heat storage unit, in order to analyze the influence of different options on the solar power plant energy yield and their impact on the kWh cost

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47

Burnett, Dougal James. "Climate change and renewable energy portfolios." Thesis, University of Edinburgh, 2012. http://hdl.handle.net/1842/6245.

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The UK has a commitment to reduce greenhouse gases by at least 80% from 1990 levels by 2050. This will see the proportion of energy generated in the UK from renewable resources such as wind, solar, marine and bio-fuels is increasing and likely to dominate the future energy market over the next few decades. However, it is unclear what effect future physical climate changes could have on the long term average energy output characteristics of individual renewable energy technologies that may dominate the low carbon energy technologies. It is also unclear how these changes to individual technologies will affect a diverse portfolio of electricity generation technologies. This thesis explores the influence of climate change on renewable electricity generation portfolios and energy security in the UK, with the aim of determining if climate change will affect renewable energy resource in such a way that may leave future low carbon generation portfolios sub-optimal. The research allows long term renewable resource variability to be reflected within models of the costs and risks associated with different electricity generation technologies and using Mean Variance Portfolio Theory (MVPT), it explores the influence of climate change on renewable energy portfolios and energy security in the UK. The scope of this study has a considerable range spanning from renewable resources through to the sensitivity of an optimal portfolio mix of generation technologies to climate change. In brief, the objectives were as follows: Characterise the variability of renewable energy resources and electricity generation output from renewable technology in the UK, in particular solar PV, on and offshore wind, for future climate scenarios for the 2050s and 2080s. Characterise the variability of electricity generation costs and explore the effect of climate change scenarios on generation costs and risk by examining the cost-risk balance of current and potential future low carbon electricity generation technology portfolios. The outcome saw distinctive changes in solar, wind, wave and hydro resource. The changes were largely negative, except in the case of solar, which increased. Levelised costs decreased for solar PV but increased for the technologies with negative resource changes. Evident changes in optimal portfolio mixes were observed and explored.

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Trotter, Ian Michael. "Essays on energy and climate change." Universidade Federal de Viçosa, 2016. http://www.locus.ufv.br/handle/123456789/8651.

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Made available in DSpace on 2016-09-16T12:14:46Z (GMT). No. of bitstreams: 1 texto completo.pdf: 1940591 bytes, checksum: 3da6520177746c26dd67daf0ea231e69 (MD5) Previous issue date: 2016-08-03
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Energy resource management is fundamental to the global economy and the well-being of its population. At the same time, changes in the climatic system threaten to deeply affect both the demand for energy and the energy supply. Firstly, it is important to understand how the existing resources can be used efficiently. Therefore, the first chapter of this thesis studies optimal operation a liquefied natural gas (LNG) importation terminal with storage, since LNG is increasingly being considered an key form of energy in the transition from fossil fuels to renewable energy sources. The main results suggest that the operation of existing infrastructure can be improved considerably. Secondly, we would like to know more about how vital societal functions could be affected by changes in the climate. In this respect, the second chapter investigates the impact of climate change on electricity demand: this chapter develops a method for incorporating weather uncertainty in electricity demand scenario generation under a non-stationary climate, then performs a case study using the method for the case of Brazil. In brief, the main results point to a significant increase in the uncertainty of electricity demand due to changes in the cliamte. Finally, after exploring the impact of climate change, it is natural to ask what can be done to mitigate the effects. The third chapter therefore performs an exploratory analysis on one of the most ambitious global efforts to mitigate climate change – the Clean Development Mechanism (CDM) – in which projects in developing countries implement greenhouse gas reduction measures to earn credits, which can be sold to entities in developed countries with reduction targets. The research aimed to uncover intended and unintended consequences of the mechanism, and thus learn valuable lessons which must be considered in future efforts. Mainly, the results suggest that mitigation projects in the poorest regions are the most sensitive to the price of carbon credits.
Gestão de recursos energéticos fundamental para a economia global e o bem-estar da população. Ao mesmo tempo, mudanças no sistema climático podem afetar profundamente a demanda por energia e o suprimento de energia. Primeiramente, é importante entender como os recursos existentes podem ser usados eficientemente. Por isso, o primeiro capítulo desta tese estuda a operação ótima de terminais de importação de gás natural liquefeito (GNL) com armazenamento. GNL cada vez mais considerado uma forma de energia chave e na transição de combustíveis fósseis as fontes renováveis. Os resultados principais sugerem que a operação de infraestrutura existente pode ser melhorada consideravelmente. Em segundo lugar, gostaríamos saber mais sobre como funções vitais da sociedade poderiam ser afetadas por mudanças no clima. Nesse contexto, o segundo capítulo examina o impacto de mudanças climáticas na demanda de energia elétrica: esse capítulo desenvolve um método para incorporar incerteza meteorológica na geração de cenários de demanda de energia elétrica sob um clima não-estacionária, e subsequentemente usa o método para estudar o caso do Brasil. Em resumo, o resultado principal sugere um aumento significativo na incerteza da demanda de energia elétrica devida as mudanças no clima. Finalmente, depois de investigar os impactos de mudanças climáticas, é natural perguntar o que pode ser feito para mitigar seus efeitos. Por isso, o terceiro capítulo apresenta uma análise exploratória de um dos esforços mais ambiciosos de mitigar mudanças climáticas – o Mecanismo de Desenvolvimento Limpo (MDL) – em que projetos em países em desenvolvimento realizam medidas de redução de emissões de gases de efeito estufa para ganhar créditos, que podem ser vendidos a entidades em países desenvolvidos com metas de redução. O objetivo da pesquisa foi descobrir consequências intencionais e não-intencionais do mecanismo, e assim e a aprender lições valiosas que devem ser considerados para esforços futuros. Os resultados sugerem que projetos de mitigação nas regiões mais pobres são os mais sensíveis ao preço de créditos de carbono.

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Caleiro, Luis Carlos Ferreira. "Dynamic simulation of strategies for thermal comfort using phase change materials." Master's thesis, Universidade de Aveiro, 2014. http://hdl.handle.net/10773/14382.

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Abstract:

Mestrado em Engenharia Civil
Nowadays, as global warming becomes one of the most urgent problems in the world, there is a need to find better ways to utilize energy: not only in the field of energy production, transmission, distribution, and consumption, but also in the area of energy storage. With energy storage technologies, it is possible to overcome the contradiction between the energy production and consumption, alleviate the tense production load of power plants at peak hours, and reduce consumers’ electricity costs by avoiding higher peak hour tariffs. Thermal energy storage, or heat and cold storage, allows the storage of heat or cold to be used later. This method needs to be reversible so it allows for multiple cycles. The technology that was studied for this effect was Phase Change Materials or PCMs. With that in mind, and with the help of dynamic building simulation software, EnergyPlus, several scenarios of an existing build that has PCM incorporated were studied in order to ascertain the real effect the technology is having on the case study, including thermal comfort.
Hoje em dia, com o aquecimento global a tornar-se um dos problemas mais urgentes da Terra, há necessidade de encontrar melhores maneiras de utilizar energia: não apenas no campo da produção de energia, transmissão, distribuição e consumo, mas também na área de armazenamento de energia. Com tecnologias de armazenamento de energia, é possível de ultrapassar a contradição entre a produção e consumo, aliviar a tensão que existe na produção nas estações de energia nas horas de pico e reduzir o custo de electricidade aos utentes ao evitar as tarifas nas horas de pico. A armazenagem de energia calorífica, do calor e frio, permite o armazenamento de calor ou frio para ser usado mais tarde. Este método precisa de ser reversível para permitir vários ciclos deste processo. A tecnologia estudada para este efeito foi os materiais que mudam de fase, ou PCMs (Phase Change Materials). Com isto em mente, e com a ajuda de software de simulação dinâmica, EnergyPlus, vários cenários de um edifício existente que tem PCM incorporado foram estudados em ordem de poder concluir o verdadeiro efeito que a tecnologia está a ter no caso estudo, incluindo o conforto térmico.

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Ng, Hui-Siong. "Low energy (K§+, ¹²C) charge exchange cross section measurements." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ60159.pdf.

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