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Yang, Chul Ho. "Paired Interactions between Kir channels and Tertiapin-Q." VCU Scholars Compass, 2013. http://scholarscompass.vcu.edu/etd/3183.
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Kir channels serve diverse and important roles throughout the human body and malfunctions of these channels are implicated in various channelopathies. Specific inhibitors for different subtypes of Kir channels are not available. However, Tertiapin-Q (TPNQ), a polypeptide isolated from honey bee venom, differentially inhibits certain subtypes of Kir channels with nanomolar affinity: ROMK1 (Kir1.1) and GIRK1/GIRK4 (Kir3.1/Kir3.4). Modification of TPNQ to increase selectivity for target channels bears great therapeutic potential. The in silico studies based on TPNQ-docked channel models, ROMK1_IRK2 (Kir1.1_Kir2.2) and GIRK2 (Kir3.2), predicted specific paired residue interactions and were experimentally validated here. In ROMK1 E123A mutant, the TPNQ sensitivity was decreased by ~2-fold while GIRK2 E127A mutant reduced the TPNQ sensitivity by greater than 10-fold. Also, we could observe the additional effect, ~ 18 fold, of GIRK1 subunits, ~1.7 fold, and E127A mutation, ~10 fold, on the TPNQ sensitivity in the heteromeric mutant channel, GIRK1/GIRK2 E152D_E127A as compared with the homomeric GIRK2 E152D. Finally, we introduced the Kir3.2 E152D mutant as a good representative of wild-type behavior particularly for the TPNQ study. Overall, this type of structure-function studies suggests an efficient and cost effective way toward design and development of specific Kir channel blockers by targeting on specific paired interactions between TPNQ and the Kir channels.
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Levinsen, Jesper F. "Paired fermionic superfluids with s- and p-wave interactions." Connect to online resource, 2007. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3284444.
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Anderson, Michelle. "Target Practice: Exploring Student TL/L1 Use in Paired Interactions." BYU ScholarsArchive, 2017. https://scholarsarchive.byu.edu/etd/6296.
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Teachers of foreign languages typically encourage their students to speak in the target language (TL) often, but due to various factors, this is not always achieved. Some reasons might include insufficient vocabulary, lack of topic knowledge, embarrassment, or simple unwillingness. Much of the existing research observes uses of the TL or native language (L1). The purpose of this study was to examine how often students use the TL in paired interactions and whether that amount has any relationship to the students' oral proficiency at the end of the course. In a SPAN 105 course at Brigham Young University, 27 students participated in this project by recording themselves during six in-class, paired interactions, after which they provided comments via questionnaires. This study was conducted using a mixed-methods approach, with both quantitative and qualitative data. The quantitative data revealed information about the time spent in the TL, as well as the time spent in the L1, and what relationship these variables had with listening comprehension and oral proficiency. The qualitative data exposed emergent findings related to TL/L1 use: helpful tools, effects of task type, pitfalls the students experienced, struggles and benefits of partnering, effects of recording, and student perceptions about the L1. The results of the study indicate a need for teacher strategies to encourage TL use in the classroom.
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Dimov, Ivailo Ivov. "Competing orders and interactions in high temperature superconductors and paired quantum hall states." Diss., Restricted to subscribing institutions, 2008. http://proquest.umi.com/pqdweb?did=1692096871&sid=1&Fmt=2&clientId=1564&RQT=309&VName=PQD.
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Higgins, Michael Joseph. "An investigation of paired pulse interactions between evoked field potentials in normal and bicuculline-superfused rat hippocampal slices." Thesis, University of Glasgow, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.320311.
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Conde, Ruiz Virginia. "The role of network interactions in timing-dependent plasticity within the human motor cortex induced by paired associative stimulation." Doctoral thesis, Universitätsbibliothek Leipzig, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-129770.
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Spike timing-dependent plasticity (STDP) has been suggested as one of the key mechanism underlying learning and memory. Due to its importance, timing-dependent plasticity studies have been approached in the living human brain by means of non-invasive brain stimulation (NIBS) protocols such as paired associative stimulation (PAS). However, contrary to STDP studies at a cellular level, functional plasticity induction in the human brain implies the interaction among target cortical networks and investigates plasticity mechanisms at a systems level.
This thesis comprises of two independent studies that aim at understanding the importance of considering broad cortical networks when predicting the outcome of timing-dependent associative plasticity induction in the human brain. In the first study we developed a new protocol (ipsilateral PAS (ipsiPAS)) that required timing- and regional-specific information transfer across hemispheres for the induction of timing-dependent plasticity within M1 (see chapter 3). In the second study, we tested the influence of individual brain structure, as measured with voxel-based cortical thickness, on a standard PAS protocol (see chapter 4). In summary, we observed that the near-synchronous associativity taking place within M1 is not the only determinant influencing the outcome of PAS protocols. Rather, the online interaction of the cortical networks integrating information during a PAS intervention determines the outcome of the pairing of inputs in M1.
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Akkaya, Munir. "Analysis of the CD200R family." Thesis, University of Oxford, 2011. http://ora.ox.ac.uk/objects/uuid:b3f89f82-16e4-471f-9c36-c42cc500c822.
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Paired receptor families, consisting of multiple genetically and structurally similar but functionally opposite activating and inhibitory cell surface receptors, are among the fine tuners of the immune regulation. Recent studies on the evolutionary origin of these receptor families have suggested links to pathogen driven diversification, according to which activating receptors continuously evolve in order to counterbalance pathogens that try to subvert the immune response by stimulating the inhibitory receptor through their virulence factors. This thesis is about the CD200R paired receptor family. This family consists of an inhibitory receptor CD200R which is expressed on various leukocytes and delivers inhibitory signals upon engagement with its ligand CD200. In this study, the possibility that the activating members of the family evolved under pathogen pressure was investigated. Genomic DNA from twenty two different mice strains was screened for the presence of members of CD200R family. The number of activating receptors varied, CD200RLe and CD200RLc were found to be mutually exclusive and three strains possessed previously unknown members of CD200R family. In addition, the possibility that CD200R family members and other paired receptors interacted directly with bacteria was tested with a new assay but only the interaction of PIR-A1 with
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Conde, Ruiz Virginia [Verfasser], Arno [Akademischer Betreuer] Villringer, Patrick [Akademischer Betreuer] Ragert, Joseph [Gutachter] Claßen, and Michael [Gutachter] Nitsche. "The role of network interactions in timing-dependent plasticity within the human motor cortex induced by paired associative stimulation / Virginia Conde Ruiz ; Gutachter: Joseph Claßen, Michael Nitsche ; Arno Villringer, Patrick Ragert." Leipzig : Universitätsbibliothek Leipzig, 2013. http://d-nb.info/1238527825/34.
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Wang, Linxiao. "Assessing interactional competence in second language paired speaking tasks." Thesis, Northern Arizona University, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=3713923.
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The last decade has witnessed growing awareness and use of paired speaking tasks in the field of second language (L2) assessment, resulting in calls for more studies on interactional competence (Ducasse & Brown, 2009; May, 2010; Taylor & Wigglesworth, 2009). This dissertation study aimed to account for the nature of peer-peer interaction in L2 paired speaking tasks through the perspectives of second language acquisition and task-based language assessment. This has been accomplished by addressing the following issues: first, understanding the construct of interactional competence at both macro- (i.e., overall interaction quality determined by degree of collaboration and task completion) and micro-levels (i.e., particular features in interactions); second, evaluating rating scales for interactional competence in terms of reliability and validity; third, examining the extent to which the distribution of interaction features predicted interaction scores; and lastly, investigating how task type affected interaction performance regarding interaction features, interaction patterns, and interaction scores. In total, 70 language learners in an English for Academic Purposes (EAP) program were paired and responded to four 2.5-minute interaction tasks. All interactions were scored on overall interaction quality by four raters using a new scale developed by the researcher and two existing scales. Then each individual interlocutor’s performance was coded for interaction features ranging from interactive listening to interactional management features. The data obtained were analyzed to answer the following questions: (1) Were hypothesized relations among interaction features supported empirically? (2) Was the new scale a reliable and valid measure? and (3) Did interaction features account for variance in interactional competence scores? Results helped refine understanding of interactional competence. First, the results of confirmatory factor analysis did not support the original model of interactive listening and interactional management features. Instead, interaction performance was better characterized by different communication functions of argument, discussion, support, and connection. Second, compared with the two existing scales, the new scale was a more reliable and valid measure. Third, features of topic connection, turn interruption, and turn overlapping were important indicators to predict scores generated by the new scale. Findings have implications for second language acquisition, L2 speaking assessment, and instruction. First, interactional competence could be operationalized in aspects of interaction features and patterns. Second, speaking assessment should include paired speaking tasks to reflect test-takers’ interactional speaking abilities. In addition, interaction rating scales should measure levels of interactions and task completeness status. Rater calibration is needed to ensure that consistent judgments can be delivered. Last, teachers can direct students’ attention to different interaction patterns and specific features, which characterize effective conversations. In summary, findings provide further understanding of interactional competence and offer insights into how to measure interaction competence in language classrooms.
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Ho, Man-wah Loretta, and 何敏華. "Student interaction and writing competence within a paired writing classroom." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2008. http://hub.hku.hk/bib/B41758134.
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Ho, Man-wah Loretta. "Student interaction and writing competence within a paired writing classroom." Click to view the E-thesis via HKUTO, 2008. http://sunzi.lib.hku.hk/hkuto/record/B41758134.
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Kley, Katharina. "Interactional competence in paired speaking tests: role of paired task and test-taker speaking ability in co-constructed discourse." Diss., University of Iowa, 2015. https://ir.uiowa.edu/etd/1663.
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This dissertation centers on the under-researched construct of interactional competence, which refers to features of jointly constructed discourse. When applied to the testing of speaking skills in a second language, interactional competence refers to features of the discourse that the two students produce together; rather than the speaking ability or performance of each person individually. This dissertation describes the construct of interactional competence in a low-stakes, paired speaking test setting targeted at students in their second year of German instruction at the college level.
The purpose of this study is two-fold. First, the study analyzes the conversational resources that are co-constructed in the test discourse to maintain mutual understanding, which is considered the basis for interactional competence. Second, the study examines the impact of task (jigsaw task and discussion task) and speaking ability-level combination (same and different ability) in the test-taker pair on the co-constructed test discourse and thus on the deployment of the conversational resources to maintain intersubjectivity. In that respect, this study also seeks to analyze how the identified conversational resources are involved in establishing and negotiating language ability identities that are displayed in the test discourse.
Conversation analytic conventions were used to investigate the interactional resources that test takers deploy to maintain mutual understanding. The procedures of repair (self-repair in response to other-initiated repair, inter-turn delays, and misunderstandings as well as other-repair in conjunction with word search activities) that emerged from the inductive analysis of the test discourse have broadened the conceptualization of interactional competence in the context of paired speaking assessments.
Frequency distributions of the interactional resources were created to provide a better understanding of the impact of task and ability-level combination on the co-constructed repair procedures. The rationale behind this analysis is the general understanding of language testers that both resources and context influence test performance. The findings from the quantitative analysis suggest that there are more similarities than differences in repair use across the jigsaw task and the discussion task. In addition, even though some trends in the co-construction of repair procedures may be attributed to the higher or lower speaking ability of the test takers, the relationship between the ability-level combination in the pair and the use of repair seems to be rather variable.
Finally, to learn more about the interrelationship between test takers’ speaking ability and interactional competence, this dissertation also approached speaking ability in terms of test takers’ co-constructed language ability identities that are displayed in the test discourse. By means of single case analyses, the study provided a detailed picture of the relationship between language ability identities and the procedures of repair, both of which are co-constructed at the discourse level. The findings from the conversation analysis show that the speaker who provides the repair is usually able to position himself or herself as the more competent or proficient speaker in the test discourse.
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Martin, Cécile. "Déposition d'énergie par production de paires dans les collisions nucléaires ultrarelativistes." Paris 11, 1989. http://www.theses.fr/1989PA112163.
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Rahal, Ghita. "Production hadronique de paires de photons à grand moment transverse." Paris 11, 1985. http://www.theses.fr/1985PA112367.
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Cette thèse décrit l’étude faite sur les paires de photons produites dans une collision hadronique de pions ou de protons avec les noyaux d’une cible de carbone. Le dispositif expérimental comprend un aimant supraconducteur et un ensemble de chambres à fils pour la reconnaissance des particules chargées, et un ensemble calorimétrique permettant la reconstruction des gerbes neutres. Ce dernier est composé d’un calorimètre électromagnétique qui échantillonne la gerbe à chaque longueur de radiation sur 24 longueurs de radiation, et d’une chambre proportionnelle qui permet de définir la position de la gerbe dans le calorimètre. La résolution en énergie σ(E)/E est de l’ordre de 0,22/√E, tandis que la résolution en position, donnée par la chambre à gerbe est de 3mm pour des gerbes isolées. L’analyse des données π⁰- π⁰ a permis d’en extraire les sections efficaces en fonction de l’impulsion transverse et de la rapidité. Elle a montré une forte corrélation angulaire entre les deux π⁰. D’autre part on a mis en évidence la présence d’un signal de paires de photons pour des π⁻ et des protons incidents. Les sections efficaces trouvées sont comparées avec les prédictions théoriques données lorsqu’on calcule les graphes de production de γ- γ jusqu’à l’ordre αs². Les prédictions semblent plus basses que la section efficace trouvée expérimentalement. Cela peut être dû à la présence de moment intrinsèque non pris en compte dans le calcul théoriqueThis thesis describes the hadronic production of two photons by incident pions and protons on a carbon target. We used the NA3 spectrometer which is composed of a cryogenic magnet and a set of multiwire proportional chambers to recognize the charged particles, and a calorimeter to detect the electromagnetic showers: the showers are sampled after each one of a total of 24 radiations length. A multiwire proportional chamber, called shower chamber, was put inside the calorimeter to be able to localize the shower. The energy resolution σ(E)/E is approximatively 22/√E, while the spatial resolution, given by the shower chamber, is approximatively 3mm for isolated showers. The π⁰ pairs have been analyzed to obtain the cross sections as a function of the transverse momentum and the rapidity. We observe a strong angular correlation between the two π⁰s. We present evidence for the production or pairs of photos by incident π⁻ and protons. The experimental cross section is compared with the theoretical expectations calculated up to order αs². The prediction seems to be lower than the experimental cross sections. This can be an effect of the primordial transverse momentum of the partons, which was not taken into account in the theoretical calculation
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Siu, Man-hung, and 蕭文鴻. "Finding motif pairs from protein interaction networks." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2008. http://hub.hku.hk/bib/B40987760.
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Siu, Man-hung. "Finding motif pairs from protein interaction networks." Click to view the E-thesis via HKUTO, 2008. http://sunzi.lib.hku.hk/hkuto/record/B40987760.
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Huang, Yi-Tzu. "Interactive patterns in paired discussions between Chinese heritage and Chinese foreign language learners." Diss., University of Iowa, 2012. https://ir.uiowa.edu/etd/2524.
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Having acquired some degree of oral proficiency but low (or non-existent) literacy, the learning of Chinese heritage learners' (CHLs) learning needs are different from those of Chinese foreign language learners (CFLs), who have learned Chinese only in the classroom setting. Although researchers have advocated for a separate curriculum for CHLs, creating a heritage track may not be an option for many Chinese programs due to insufficient enrollment and limited resources. Huge proficiency variations among CHLs also make it difficult to provide a language curriculum that fits the needs of all learners. Therefore, CHLs are assigned to classes with CFLs in most Chinese language programs. From a pedagogical point of view, uneven proficiency levels are a great concern for instructors who teach a language class with students of different language backgrounds and with varying abilities, especially when assigning students to work in pairs or small groups. Although CHL-CFL paired interaction has become a common phenomenon in Chinese language classes, it has not been fully explored.
Grounded in sociocultural theory, this research explores the nature of dyadic interaction between Chinese heritage learners (CHLs) and Chinese foreign language learners (CFLs) in a classroom setting. It investigates the roles that Chinese heritage learners and their foreign language peers play in paired discussions, how learners' proficiency gaps influence the dynamics of paired interaction, and whether peer-peer collaboration affects learners' individual oral performance.
In this study, data were collected in three intermediate-level Chinese classes. Participants first filled out a language background survey to lead to a better understanding of the environments in which they use Chinese. Next, they took two proficiency tests to assess their comprehensive Chinese skills. Over the course of a semester, ten CHL-CFL pairs engaged in paired discussions on six different occasions. Before and after each pair work session, each participant was required to give an individual verbal report assessing the influence of paired interaction on his or her oral performance. After data from the six sessions were collected, participants took an end-of-study survey, which provides their perceptions about paired discussion and their roles in paired interaction over the research period.
According to the findings, three interaction patterns (passive collaboration pattern, active collaboration pattern, and peer-tutoring pattern) were identified. The results of this study show that CHLs' language background and the amount of Chinese language exposure determined the CHL-CFL proficiency gaps in each pair, and further influenced the pattern of paired interaction. Learners generated more LREs (Language-related episodes) and were more likely to acquire knowledge from pair work when the degree of interaction mutuality was high. Even when the proficiency gaps were large, the less proficient learners still could transfer new knowledge to their independent work.
To conclude, this study may be of importance in presenting the dynamics of CHL-CFL paired interaction in a mixed Chinese language class, as well as in providing instructors with a better understanding of how different factors such as interlocutors' proficiency gaps, individual participants' beliefs and attitudes relate to their interaction behaviors and subsequent independent performance.
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Frazao, Bordalo e. Sa Maria Paula. "Etude des distributions de l'impulsion transverse de paires de muons produits dans les interactions." Grenoble 2 : ANRT, 1986. http://catalogue.bnf.fr/ark:/12148/cb37598041k.
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Esnault, Léo. "Production de photons gamma lors de l'interaction laser-matière et création de paires électron-positron par collision de photons." Thesis, Bordeaux, 2021. http://www.theses.fr/2021BORD0077.
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La création de paires électron-positron par collision de deux photons réels (processus Breit-Wheeler linéaire) est un des processus de base de l’électrodynamique quantique, et est supposé sous-tendre un large éventail de phénomènes astrophysiques des hautes énergies, tels que l’opacité de l’Univers aux photons TeV ou la production de plasmas de paires au voisinage d’objets compacts (AGN, pulsars). Cependant, ce processus n’a jusqu’à présent jamais été directement observé en laboratoire depuis sa prédiction en 1934, et ce principalement à cause de l’absence de sources de photons d’énergie autour du MeV de suffisamment haut flux. Grâce au développement continu des systèmes laser de haute puissance et de haute intensité, la production de telles sources de photons devient toutefois désormais envisageable. Malgré la diversité des approches possibles pour la génération de photons énergétiques par laser, de précédentes estimations semblent indiquer que les sources produites : par rayonnement de freinage d’électrons dans la matière (Bremsstrahlung), ou via les processus Compton inverse linéaire ou Compton inverse multiphoton (parfois appelé synchrotron-like), soient des candidates parmi les plus crédibles pour la production de paires électron-positron par collision de deux photons réels. L’interaction de ces photons multi-MeV avec de la matière peut toutefois aussi créer d’autres paires électronpositrons, qui pourraient constituer une source de bruit pour la détection de ce processus. L’objectif de cette thèse est d’optimiser la production de photons d’énergies autour du MeV générés lors de l’interaction d’un laser avec différent types de cibles (cibles solides simples ou structurées) afin de préparer des expériences de collision de photons sur des installations laser existantes ou en cours de construction. Un modèle semi-analytique permet tout d’abord d’optimiser la production de paires électron-positron par le processus Breit- Wheeler linéaire en fonction des paramètres des sources de photons. En particulier il est montré que, pour des sources de photons produits par Bremsstrahlung, les installations laser existantes permettent d’ores et déjà d’atteindre les distributions en énergies optimales, permettant ainsi d’envisager de telles expériences à haut taux de répétition. Cette étude est complétée par des simulations numériques permettant de modéliser l’accélération d’électrons lors de l’interaction du laser avec des cibles structurées (via un code Particle-In-Cell), la génération des photons gamma lors de la propagation d’électrons dans la matière (via un code Monte Carlo) ainsi que la création de paires électron-positron lors de la collision de ces photons gamma (via le code TrILEns). Ces développements pourraient alors servir de base à la préparation de futures expériences sur des installations laser actuellesElectron-positron pair creation by the mean of two real photon collision (linear Breit-Wheeler process) is one of the most basic quantum electrodynamics process, and is believed to underlie a large amount of high energy astrophysical phenomena, such as the Universe opacity to TeV photons or the production of pair plasmas near compact objects (AGN, pulsars). However, this process has never been directly observed in the laboratory since its prediction in 1934, mainly because of the absence of high flux MeV-range photon sources. Due to the continuous development of high-power and high-intensity laser systems, the production of such photon sources become however conceivable. Despite the diversity of methods to produce energetic photons by lasers, previous estimates seems to show that the radiation sources produced whether by the slowing-down of electrons in matter (Bremsstrahlung), by the linear inverse Compton scattering process, or by the multi-photon inverse Compton scattering process (sometimes called synchrotron-like) are among the most credible sources for the electron-positron pair production by two real photon collisions. The interaction of such multi-MeV photons with matter could however creates other electron-positron pairs, which could constitute a background noise for the detection of this process. The goal of this thesis is to optimize the production of MeV-range gamma photons by the mean of the interaction of a laser with various kind of targets (simple or structured solid targets) in order to prepare photon-photon collision experiments on existing or currently building laser systems. A semi-analytical model allow firstly to optimize linear Breit-Wheeler pair production in term of the photons sources parameters. Particularly it is shown that, concerning Bremsstrahlung photon sources, the current laser systems already permit to reach the optimum photon energy distributions, opening the possibility to design such experiments at high repetition rate. This study is completed with numerical simulations modeling the electron acceleration in the laser-target interaction (via a Particle-In-Cell code), the gamma photon generation by the electron propagation in matter (via a Monte Carlo code) and the electron-positron pair production in photon-photon collisions (via the TrILEns code). These findings could then be used as a basis to design such experiments on existing or currently building laser systems
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Cournol, Anne. "Transitions landau-zener de paires d'atomes de Rydberg froids en interaction dipole-dipole." Phd thesis, Université Paris Sud - Paris XI, 2011. http://tel.archives-ouvertes.fr/tel-00661626.
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Cette thèse porte sur l'étude des interactions dipôle-dipôle entre des atomes de Rydberg froids formés au sein d'un jet supersonique, en particulier sur l'étude des transitions Landau-Zener autour d'une résonance de Förster dans des sytèmes de paires d'atomes de Rydberg. L'adiabaticité de la transition dépend de la distance entre les atomes de la paire et est contrôlée par l'application d'un champ électrique homogène dépendant du temps. L'étude des processus binaires, non collisionnels et dont l'efficacité est contrôlé par l'expérimentateur, permet de sonder l'environnement de chaque atome et constitue une mesure de la distribution de plus proches voisins. Nous en déduisons une méthode originale de mesure directe et précise de la densité d'un gaz de Rydberg. Cette méthode ne nécessite ni la connaissance du nombre d'atomes de Rydberg ni celle du volume du gaz. Après un passage adiabatique de paire, les atomes de Rydberg constituant cette paire se trouvent dans un état intriqué. Nous proposons une méthode pour prouver leur intrication, fondée sur la mesure de la fluctuation quantique au cours d'oscillations de Rabi entre des états de paire.
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VAN, DEN BOSSCHE MATHIAS. "Fermions a une dimension : etude du modele a interaction par sauts de paires." Paris 6, 1996. http://www.theses.fr/1996PA066718.
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Nous etudions le modele a interaction par sauts de paires unidimensionnel a temperature nulle. Il existe une controverse quant a la nature de son etat fondamental. En effet, deux etudes numeriques a petites tailles indiquent que le modele presente une transition de phase dans l'etat fondamental pour une valeur finie du couplage. Inversement, le groupe de renormalisation perturbatif exclut une telle transition. Nous presentons une serie de resultats obtenus d'abord par diagonalisation exacte du hamiltonien, puis groupe de renormalisation numerique par la matrice densite. En interpretant ces resultats dans le cadre de la theorie des liquides de luttinger nous proposons un scenario qui permet de rendre compte de tous les resultats obtenus sur ce modele. A basses energies, le modele est donc equivalent au modele de hubbard attractif, et ne presente pas de transition de phase.
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Belkacem, Ali. "Etude expérimentale et théorique des effets directionnels sur le rayonnement et la création de paires dans un cristal à des énergies de l'ordre de 100 GeV." Lyon 1, 1986. http://www.theses.fr/1986LYO10032.
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Nous avons fait une étude théorique et expérimentale de l'interaction électromagnétique de particules chargées ultrarelativistes et de photons de très haute énergie (~ 100 GeV) avec un cristal. La partie expérimentale a été réalisée au centre européen de recherche nucléaire (CERN). Nous avons mesuré la production de paires électron-positon dans un cristal mince à partir d'un faisceau incident de photons. Nous avons observé que lorsque l'énergie des photons est supérieure à 30 GeV environs, le taux de production de paires à partir d'un faisceau aligné le long d'une direction cristalline simple est bien supérieur à la valeur attendue dans le cas d'une cible amorphe, notamment par la théorie de Bethe et Heitler. . .
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Bourdel, Thomas. "Gaz de Fermi en interaction forte: Du condensat de molécules aux paires de Cooper." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2004. http://tel.archives-ouvertes.fr/tel-00008271.
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Ce mémoire de thèse décrit les propriétés d'un gaz de Fermi dégénéréen interaction forte. Tout d'abord, nous étudions d'un point de vue
théorique la limite au refroidissement d'un gaz de fermions imposée
par l'existence de pertes d'atomes. Un gaz de lithium fermionique 6Li
est ensuite étudié au voisinage d'une résonance de Feshbach en onde s. En changeant le champ magnétique, on peut contrôler le signe et
la force des interactions effectives entre atomes. Nous montrons la
formation efficace de molécules faiblement liées constituées de deux
fermions. Ces résultats sont interprétés par un modèle d'équilibre
thermodynamique entre atomes et molécules. Le principe de Pauli
confère à ces bosons composites une extraordinaire stabilité proche du
pic de la résonance. Cette propriété nous a permis de produire un
condensat de Bose-Einstein (BEC) de molécules et de mesurer
l'interaction entre les molécules à basse température. En augmentant
le champ magnétique au-delà de la résonance de Feshbach, on s'attend à
ce que le gaz, à basse température, subisse une transition de phase de
type BCS (Bardeen, Cooper, Shrieffer) analogue à la transition
supraconductrice dans les métaux. Proche de résonance, le gaz est un
système à N-corps en interaction forte, difficile à traiter
théoriquement. Expérimentalement, nous avons étudié l'expansion du
gaz dans cette région qui correspond à la transition entre un
condensat de molécules et une phase BCS. Enfin, nous avons
caractérisé le comportement des pertes au voisinage de résonances de
Feshbach en onde p.
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Mattson, Stephanie Margaret Rossman George Robert. "Optical expressions of ion-pair interactions in minerals /." Diss., Pasadena, Calif. : California Institute of Technology, 1985. http://resolver.caltech.edu/CaltechETD:etd-04082005-133814.
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Zou, Yan. "Study of Lone Pair-Arene Interactions in Solution." Miami University / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=miami1186024674.
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Pradines, Vincent. "Instabilités périodiques de Marangoni en système biphasique liquide/liquide : rôle et propriétés de paires d'ions tensioactives." Toulouse 3, 2006. http://www.theses.fr/2006TOU30155.
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Oscillations of the electrical potential and interfacial tension have been studied during mass transfer in water/dichloromethane biphasic systems: CTAB/picric acid and SDS/TAAB for which, the chain length of the tetraalkylammonium was varied (from ethyl to butyl). A detailed analysis of the signals recorded allowed us to confirm the hydrodynamic origin (Marangoni instability) of the oscillations. We have determined the physico-chemical properties of all species involved (partition and adsorption constant, molecular area, and association constant of the ion pairs). For this, measurements of the surface tension, UV/Visible spectrophotometry and mass spectrometry have been performed. For the SDS/TAAB system, we have observed increasing association of TAADS ion pairs with chain length. We have also carried out theoretical calculations (DFT, Ab-initio) to highlight a geometry supporting the hydrophobic interactions between the two ions.
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Vivares, Denis. "Interactions en solution et cristallisation de l'urate oxydase." Paris 6, 2003. http://www.theses.fr/2003PA066336.
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Ensergueix, Pierre Jean. "La formation au tutorat réciproque entre pairs pour l'acquisition d'habiletés motrices complexes : l'exemple du tennis de table au collège." Thesis, Bordeaux 2, 2010. http://www.theses.fr/2010BOR21706/document.
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Cette recherche est une contribution à l’identification des conditions d’efficacité des procédures d’apprentissage entre pairs dans le domaine des activités physiques sportives. Elle vise à explorer l’intérêt d’une formation au tutorat réciproque entre pairs pour l’acquisition d’habiletés motrices complexes en tennis de table au collège. Le cadre théorique est celui de la psychologie sociale du développement et des acquisitions. Notre démarche empirique prend en compte à la fois un contexte quasi-expérimental (1e étude) et un contexte de classe (2e étude). Ensemble, les études confirment la nécessité de préparer les élèves à l’interaction réciproque. Nos résultats indiquent que les participants de la condition de tutorat formé ont retiré des bénéfices moteurs, (méta)cognitifs et socio-émotionnels supérieurs à ceux de leurs homologues de la condition de tutorat spontané. Ils montrent également l’absence d’effet de la mixité dans les dyades et révèlent une mise en œuvre de la procédure, par l’enseignant lui-même, conforme aux attentes. Par ailleurs, ce travail se propose de clarifier la nature des processus sous-jacents à l’efficacité du tutorat réciproque, au moyen notamment d’une analyse des interactions dyadiques. Enfin, une attention particulière est accordée à l’explicitation des dispositifs de formation employés dans chacun des contextesThis research is a contribution to the identification of efficacy conditions of peer learning strategies in the domain of sport and physical activities. It aims at exploring the interest of a reciprocal peer tutoring training for the acquisition of complex motor skills in table tennis at secondary school level. The theoretical framework is social development and learning psychology. Our empirical intervention considers both a quasi-experimental context (1st study) and a classroom context (2nd study). Together, studies confirm the necessity of preparing students for reciprocal interaction. Participants from the trained tutoring condition got higher motor, (meta)cognitive and socio-emotional gains than those of their counterparts from the untrained tutoring condition. No differences between mixed vs. non-mixed dyads were found and the implementation of the procedure by the teacher himself was in accordance with our expectations. Furthermore, this work intends to clarify the mechanisms underlying the effectiveness of reciprocal tutoring, using notably an analysis of dyad interactions. Finally, a particular interest is given to details of the training procedures implemented in each context
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Noyes, Nicole. "Intéractions sociales entre pairs et utilisation de concepts catégoriels." Aix-Marseille 1, 1995. http://www.theses.fr/1995AIX10026.
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Dans une perspective tres pragmatique de psychologie de l'education, cette recherche vise essentiellement a etudier l'impact de situations d'interactions sociales dans l'utilisation de concepts categoriels chez des enfants de 7-9ans. Le cadre general de reference est celui de la "psychologie sociale genetique". Un premier dispositif experimental (le "jeu de devinettes") a pour objectif d'etudier les effets simultanes de deux types de dynamiques interactives suscitees par une situation tres epuree de communication sociale avec feed-back et une situation de co-elaboration. Ce dispositif permet egalement de comparer les effets de ces deux types de dynamiques interactives selon le milieu d'origine des sujets. Un second dispositif (les"rangements dichotomiques de mots etiquettes") vise a etudier uniquement l'impact d'une interaction de coelaboration sur l'utilisation de concepts categoriels. L'accent est mis sur les significations de la tache construites par les sujets dans la situation de resolution et sur le role de la co-elaboration dans la clarification de la representation de la tacheIn a psychology of education point of view, this research is aimed at studying the effects of social interaction situations in the utilization of categorical concepts by 7-9 old children. It refers to the general frame work of social psychology of development. The first experimental set (guess game) studies both the effects of two interactive dynamic types given rise by a very simple social communication situation with feddback and by a co-elaboration situation. This set also allows to compare these two interactive dynamic types according to the social origine of the children. A second experimental set (dichotomic sortings of world-labels) is aimed at studying the only effects of a co-elaboration situation in the utilization of categorical concepts. It stresses on the construction of the meanings of the solving situation by the subjects and on the influnce of a co-elaboration situation in the clarification of the representation of the task
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Laiou, Petroula. "Data-driven analysis of interactions between pairs and ensembles of coupled dynamics." Doctoral thesis, Universitat Pompeu Fabra, 2017. http://hdl.handle.net/10803/442973.
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The characterization of interactions between coupled dynamics from their signals is important for the understanding of real-world systems. The particular aspect of the detection of directional interactions has a central position in the analysis of dynamics. In simple unidirectionally coupled dynamics directional interactions can be achieved by applying data-driven approaches. However, for more complex dynamics the characterization of their directional interactions is not so straightforward. To address this problem we follow a data-driven approach by analyzing signals of pairs and ensembles of non-identical coupled dynamics. In particular, we use a nonlinear state-space approach and a phase-based approach. For the pairs of bidirectionally coupled dynamics, we introduce the notion of the coupling impact that allows us to better reveal the real effect that one dynamics has on the other for different degrees of asymmetry. Furthermore, we show that the coupling and its direction can be detected even for large ensembles of dynamics. Our results demonstrate that directional interactions in complex dynamics can be successfully inferred from the analysis of their signals. Hence, our work shows that the approaches are promising for a reliable detection of directional interactions from real-world signals.La caracterización de interacciones entre dinámicas acopladas a partir de sus señales, es importante para entender los sistemas del mundo real. Particularmente, la detección de interacciones direccionales tiene un papel fundamental en el análisis de dinámicas. En las dinámicas acopladas unidireccionalmente, las interacciones direccionales pueden lograrse mediante el uso de técnicas dirigidas por datos. Sin embargo, para dinámicas más complejas, la caracterización de sus interacciones direccionales no es tan trivial. Para abordar el tema, hemos utilizado una medida basada en datos analizando señales de pares y grupos de dinámicas acopladas no idénticas. En particular, utilizamos una medida de espacio de estados no linear y una medida basada en fases. Para los pares de dinámicas acopladas bidireccionalmente, presentamos el concepto de impacto de acoplamiento que nos permite desvelar mejor el efecto real que tiene una dinámica sobre la otra con distintos niveles de asimetría. Además, demostramos que el acoplamiento y su dirección pueden ser detectados incluso para grandes conjuntos de dinámicas. Nuestros resultados ponen de manifiesto que las interacciones direccionales en dinámicas complejas pueden ser entendidas satisfactoriamente a partir del estudio de sus señales. Por lo tanto, nuestro trabajo evidencia que estas técnicas son prometedoras para la detección fehaciente de interacciones direccionales de señales del mundo real.
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Poudel, Pramod Prasad. "NOVEL AROMATIC ION–PAIRS: SYNERGY BETWEEN ELECTROSTATICS AND Π-FACE AROMATIC INTERACTIONS." UKnowledge, 2012. http://uknowledge.uky.edu/chemistry_etds/4.
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This dissertation focuses on the design and study of charged aromatic molecules where weak π-π interactions synergize with electrostatic interactions to enhance the overall interaction between aromatic moieties. Each chapter investigates some aspect of this hypothetical synergy between electrostatics and π-face aromatic cohesion.
The first chapter unveiled the importance of electrostatics in the intramolecular stacking of flexible aromatic molecular templates 1-2Br and 2a. While our previous studies found dicationic molecular template 1-2Br to have intramolecular π-stacking between electron poor pyridinium and electron rich xylylene moieties, no such stacking interaction was observed in the neutral analog 2a.
Chapter two systematically explored the stacking pattern of electron poor aromatics in the form of oxygen- and / or nitrogen- substituted triangulenium cations, [1(NR)3]+ and [1(O)3(OH)3]+. As indicated in the chemical literature, triazatriangulenium cations [1(NR)3]+ with N- ethyl (and longer alkyl chains) chains were found to pack as face-to-face dimers. This study found the formation of columnar, face-to-face, n-meric association between aromatic cations in the structures with decreased steric interactions of the side chains in the stacking planes ([1(NMe)3]+ and [1(O)3(OH)3]+). Similar iso-structural triangulene based aromatic anions, (2)- and (3)2- didn’t indicate any facial interactions in the solid states.
The possible synergy between unit charge electrostatics and π-face aromatic interactions was explored in aromatic ion pairs 1•2 of triangulene based aromatic cations and aromatic anions. This charge-assisted π-π stacking seems to be the novel way of getting strong π-system interactions where the strongest non-covalent force and the weakest non-covalent force: ionic bonding and π-stacking respectively synergize together. The π-π interaction between ionic aromatics in the solid state was investigated by means of single crystal x-ray diffraction and powder x-ray diffraction (PXRD). The interaction in the solution state was examined by UV-Vis spectroscopy, electrospray ionization mass spectroscopy (ESI-MS) and electrochemical studies. Studies found that optimal synergy was possible only in the ion pairs with no steric interactions of alkyl (or aryl) side chains in the stacking planes (1(O)3•2 & 1(NMe)3•2) and the interaction was found to be comparable with the strongest radical-assisted π-stacking described in the chemical literature.
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Nouvel, Nicolas. "Lewis acid-base pairs and host-guest interactions : towards dynamic functional materials." Thesis, University of Cambridge, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.609310.
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Zsoldos, Jeffrey S. "An experimental investigation of interacting wing-tip vortex pairs." Thesis, This resource online, 1992. http://scholar.lib.vt.edu/theses/available/etd-11242009-020215/.
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Golshan, Shahram Mohammad-Mehdi. "Photon Exchange Between a Pair of Nonidentical Atoms with Two Forms of Interactions." Thesis, North Texas State University, 1987. https://digital.library.unt.edu/ark:/67531/metadc331447/.
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A pair of nonidentical two-level atoms, separated by a fixed distance R, interact through photon exchange. The system is described by a state vector which is assumed to be a superposition of four "essential states": (1) the first atom is excited, the second one is in the ground state, and no photon is present, (2) the first atom is in its ground state, the second one is excited, and no photon is present, (3) both atoms are in their ground states and a photon is present, and (4) both atoms are excited and a photon is also present. The system is initially in state (1). The probabilities of each atom being excited are calculated for both the minimally-coupled interaction and the multipolar interaction in the electric dipole approximation. For the minimally-coupled interaction Hamiltonian, the second atom has a probability of being instantaneously excited, so the interaction is not retarded. For the multipolar interaction Hamiltonian, the second atom is not excited before the retardation time, which agrees with special relativity. For the minimally-coupled interaction the nonphysical result occurs because the unperturbed Hamiltonian is not the energy operator in the Coulomb gauge. For the multipolar Hamiltonian in the electric dipole approximation the unperturbed Hamiltonian is the energy operator. An active view of unitary transformations in nonrelativistic quantum electrodynamics is used to derive transformation laws for the potentials of the electromagnetic field and the static Coulomb potential. For a specific choice of unitary transformation the transformation laws for the potentials are used in the minimally-coupled second-quantized Hamiltonian to obtain the multipolar Hamiltonian, which is expressed in terms of the quantized electric and magnetic fields.
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Clark, Lindsey Renee. "Inferring the interaction of two Chaco-era communities through painted ceramic design analyses." Pullman, Wash. : Washington State University, 2010. http://www.dissertations.wsu.edu/Thesis/Spring2010/L_Clark_041310.pdf.
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Thesis (M.A. in anthropology)--Washington State University, May 2010.Title from PDF title page (viewed on May 21, 2010). "Department of Anthropology." Includes bibliographical references (p. 67-72).
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Wantz, Bauer Frédérique. "Interactions entre pairs dans l'appropriation d'une langue étrangères : travail de groupe entre apprenants." Rouen, 2001. http://www.theses.fr/2001ROUEL403.
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Ce travail est une tentative d'analyse des interactions entre apprenants dans le cadre d'un travail en petits groupes dans la classe de langue étrangère. Notre l'hypothèse était qu'au-delà de la traditionnelle relation enseignant-enseigne, l'interaction entre apprenants, entre pairs, pouvait également jouer un rôle dans l'apprentissage d'une langue étrangère et nous avons cherché à préciser dans quelle mesure. Notre travail se situe dans le cadre théorique général de l'interactionnisme. Nous proposons l'analyse d'un corpus de classe présentant des interactions entre apprenants en faisant varier d'une part le niveau en langue cible et d'autre part le type d'activité. Nous comparons ensuite les résultats obtenus sur ce corpus à ceux d'une enquête dont le but était de mieux cerner les représentations des apprenants en ce qui concerne le travail de groupe. Nous reprenons dans notre travail la notion de "négociation du sens" qui se trouve au centre de nombreux travaux concernant l'interaction entre apprenants. Notre analyse de la relation paritaire en prenant en considération les phénomènes d'alternance de langue, les procédés de correction et la relation d'aide entre apprenants, permet de montrer que l'intérêt de ce type d'interaction ne se limite pas à fournir des conditions favorables à l'émergence de procédés de négociation du sens, relevant pour nous d'une stratégie d'apprentissage parmi d'autres. Nous soulignons en particulier les relations étroites qui unissent la sphère cognitive et la sphère socio-affective dans les processus d'apprentissage chez l'adulte. Et c'est aussi parce qu'elle permet aux apprenants de mettre en œuvre dans un cadre plus sécurisant un travail de "figuration" que l'interaction en petits groupes revêt un intérêt particulier dans l'apprentissage d'une langue étrangère.
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Macdonald, Ryan. "The Effects of Trimethylamine-N-Oxide and Guanidinium Chloride on Aqueous Hydrophobic Contact-Pair Interactions." Elsevier - Biophysical Chemistry, 2013. http://hdl.handle.net/1993/30162.
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Trimethylamine-N-oxide (TMAO) and guanidinium chloride (GdmCl) are both highly studied molecules in the field of protein folding/unfolding. Thermodynamic studies have shown that TMAO, an organic osmolyte, is a strong stabilizer of the protein folded state, while GdmCl is known to be one of the most effective protein denaturants. Although TMAO and GdmCl are well studied the mechanism by which they stabilize and denature proteins, respectively, is not well understood. In fact there are few studies looking at their effects on hydrophobic interactions. In this work we determine the effect of TMAO and GdmCl on hydrophobic interactions, by looking at the model system of phenyl and alkyl hydrophobic contact pairs. Contact pair formation is monitored through the use of fluorescence spectroscopy, i.e., measuring the intrinsic phenol fluorescence being quenched by carboxylate ions. Hydrophobic interactions are isolated from other interactions through a developed methodology. The results show that TMAO addition to the aqueous solvent destabilizes hydrophobic contact-pairs formed between phenol and carboxylate ions. The TMAO acts as a “denaturant” for hydrophobic interactions. For GdmCl the data shows that for small alkyl groups, acetate and propionate, hydrophobic contact-pairs are slightly stabilized or are not affected, respectively. For the larger alkyl groups GdmCl disrupts contact pair formation and destabilizes them. GdmCl’s effect on hydrophobic interactions shows a size dependence on carboxylate ion size, i.e., as carboxylate ion tail length increases the contact pair formed with phenol is destabilized to a greater degree.
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Naïm, Charles-Joseph. "Cold nuclear matter effects in Drell-Yan process and charmonium production." Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPASP038.
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Le phénomène de perte d’énergie des quarks et des gluons se propageant dans un milieu en interaction forte a été mis en évidence pour la première fois dans les collisions d’ions lourds par les expériences auprès des accélérateurs RHIC et LHC. Une autre manière de sonder les propriétés de la matière nucléaire est d'étudier la production de processus durs dans les collisions hadron-noyau. En effet, dans ce cas, le milieu nucléaire est simple : sa densité ainsi que sa taille sont connues. Dans cette thèse, le processus Drell-Yan et la production de Jpsi ont été étudiés à travers une analyse expérimentale et phénoménologique. La collaboration COMPASS au CERN a collecté un nombre significatif d’événements Drell-Yan et Jpsi en utilisant un faisceau de pions négatifs d’énergie égale à 190 GeV sur deux cibles nucléaires : aluminium (Al) et tungstène (W). De l’analyse des événements à l’extraction des rapports des sections efficaces nucléaires, en passant par l’analyse Monte-Carlo, cette thèse décrit chaque étape de l’analyse expérimentale. Enfin, une analyse basée sur l'ensemble des données DY et Jpsi existantes, incluant celles de l'expérience COMPASS, a permis de réaliser une extraction précise des propriétés de transport de la matière nucléaire froideThe Jet Quenching phenomenon observed in the heavy ions collisions at the LHC and RHIC made it possible to highlight the radiation energy loss effects of quarks and gluons propagating in a QCD medium. Another way to the properties of the nuclear matter is to consider the production of hard processes in hadron-nuclei collisions. In this case, the nuclear medium, the cold nuclear matter, is simple; its density and size are known. The Drell-Yan process and charmonium production are investigated in this thesis through an experimental and phenomenological study.The COMPASS collaboration at CERN collected the Drell-Yan and Jpsi events in high statistics in pion-nuclei collisions on two nuclear targets: tungsten (W) and aluminium (Al). From the signal extraction to the evaluation of nuclear dependence of the cross sections, including Monte Carlo simulations, each step of the experimental analysis is discussed. Finally, a global analysis of the Drell-Yan and Jpsi nuclear world data, including the COMPASS preliminary data, was performed. It highlighted the radiative energy loss and transverse momentum broadening effects. A precise extraction of the properties of the transport in the nuclear matter was carried-out
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Toczyłowski, Rafał R. "From noble gas dimers to nucleic acid base pairs studies of weak intermolecular interactions /." Oxford, Ohio : Miami University, 2004. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=miami1102106714.
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Shaffer, Irena Marie. "Effects of Echolocation Calls on the Interactions of Bat Pairs using Transfer Entropy Analysis." Thesis, Virginia Tech, 2020. http://hdl.handle.net/10919/98672.
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Many animal species, including many species of bats, exhibit collective behavior where groups of individuals coordinate their motion. Most bats are unique among these animals in that they use the active sensing mechanism of echolocation as their primary means of navigation. Due to their use of echolocation in large groups, bats run the risk of signal interference from sonar jamming. However, several species of bats have developed various strategies to prevent interference which may lead to different behavior when flying with conspecifics than when flying alone. This thesis seeks to explore the role of this sensing on the behavior of bat pairs flying together. Field data from a maternity colony of gray bats (Myotis grisescens) were collected using an array of cameras and microphones. These data were analyzed using the information theoretic measure of transfer entropy in order to quantify the interaction between pairs of bats and to determine the effect echolocation calls have on this interaction. Results show that there is evidence of information transfer in both the speed of the bats and their turning behavior, and that such evidence is absent when we consider their heading directions. Unidirectional information transfer was found in some subsets of the data which could be evidence of a leader-follower interaction.Master of Science
Manyanimalspeciesexhibitcollectivebehaviorwheregroupsofanimalscoordinatetheir motion, as in flocking or schooling. Many species of bats also demonstrate this behavior. Bats are unique among these animals in that they use echolocation as their primary means of navigation. Bats produce ultrasonic pulses or calls and listen to the returning echo to "visualize" their environment. Bats using echolocation in large groups run the risk of other bat calls interfering with their ability to hear their own calls. They have developed various waystopreventinterferencewhichmayleadtodifferentbehaviorwhenflyingwithotherbats thanwhenflyingalone. Fielddatafromamaternitycolonyofgraybatswerecollectedusing a system of cameras and microphones. These data were analyzed to quantify the interaction between pairs of bats and to determine the effect echolocation calls have on this interaction. Results show that there is evidence of information transfer about both the speed of the bats and their turning behavior. There was also evidence of a possible leader-follower interaction in some subsets of the data.
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Toczylowski, Rafal R. "FROM NOBLE GAS DIMERS TO NUCLEIC ACID BASE PAIRS: STUDIES OF WEAK INTERMOLECULAR INTERACTIONS." Miami University / OhioLINK, 2004. http://rave.ohiolink.edu/etdc/view?acc_num=miami1102106714.
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Boström, Mathias, Clas Persson, Barry W. Ninham, Patrick Norman, and Bo Sernelius. "Resonance interaction induced by metal surfaces catalyzes atom-pair breakage." Linköpings universitet, Beräkningsfysik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-92701.
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We present the theory for retarded resonance interaction between two identical atoms at arbitrary positions near a metal surface. The dipole-dipole resonance interaction force that binds isotropically excited atom pairs together in free space may turn repulsive close to an ideal (totally reflecting) metal surface. On the other hand, close to an infinitely permeable surface it may turn more attractive. We illustrate numerically how the dipole-dipole resonance interaction between two oxygen atoms near a metal surface may provide a repulsive energy of the same order of magnitude as the ground-state binding energy of an oxygen molecule. As a complement we also present results from density-functional theory.Funding Agencies|VR|C048510170529001|STEM|34138-1|
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Rakotozafindrabe, Andry. "Etude de la production du J/psi dans le canal muonique dans les collisions Cu+Cu à 200 GeV par paire de nucléons dans l'expérience PHENIX." Palaiseau, Ecole polytechnique, 2007. http://www.theses.fr/2007EPXX0026.
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Les collisions d'ions lourds relativistes permettent d'étudier la production du plasma de quarks et de gluons (QGP), état dans lequel serait la matière hadronique au-delà d'une température de l'ordre de 200~MeV. Le J/\psi, état lié~c\bar{c}, est une des sondes utilisées pour observer le QGP. Son taux de production peut être modifié par divers effets en compétition: les effets nucléaires froids et ceux attendus en cas de production du QGP. Une suppression anormale du J/\psi (au-delà des effets froids) a déjà été vue par l'expérience NA50 (SPS) dans les collisions Pb~+~Pb les plus centrales. L'expérience PHENIX (RHIC) poursuit cette étude à une énergie environ dix fois plus élevée. Nous avons étudié la production du J/\psi\to\mu^+\mu^- dans les collisions Cu~+~Cu effectuées en 2005 à une énergie de 200~GeV par paire de nucléons. Les résultats obtenus apportent des informations importantes sur les effets froids: ils permettent d'améliorer de manière significative la précision obtenue dans les collisions à petit nombre de nucléons participants, où le QGP ne peut être produit. Ils confirment la similitude des suppressions déjà observées au RHIC dans les collisions Au~+~Au et au SPS; ce constat restant à corroborer par des mesures plus précises des effets froids au RHIC. Les résultats combinés Au~+~Au et Cu~+~Cu mettent aujourd'hui en défaut la plupart des modèles théoriques, et pourraient favoriser l'hypothèse d'une production ! secondaire du J/\psi dans le milieu (recombinaison).
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Chen, Jing. "SOLUTION AND SOLID STATE INTERACTIONS BETWEEN IONIC π-SYSTEMS." UKnowledge, 2006. http://uknowledge.uky.edu/gradschool_diss/289.
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Although attractive interactions between π systems (π-π interaction) have been known for many years, understanding of its origin is still incomplete. Quantitative measuring of π-stacking is challenging due to the weak nature of the π-π interaction. This dissertation aims at elucidating a quantitative conformational analysis by NMR ring current anisotropy of an organic compound capable of intramolecular π-stacking in solution and studying charge effects on the stacking of π-systems. This dissertation offers four contributions to the area. (1) A general approach to four-state, conformational analysis based on the magnetic anisotropy of molecules undergoing fast dynamic exchange is described. (2) Study unveiled the importance of charges in the conformation of a dication in the solution. (3) Novel aromatic salt pairs of triangulene derivatives with the delocalized cation-anion interaction were synthesized and studied. (4) Study unveiled ionic π-systems preferred face-to-face stacking due to strong cation-π and anion-cation attractions.
A general protocol for the application of magnetic anisotropy to quantitative multi-state conformational analysis of molecules undergoing fast conformational exchange was suggested in the current study. The reliability of this method of conformational analysis was checked by the mass balance. VT-NMR was also conducted to study the enthalpic parameters. This technique can be further used to study canonical interactions such as ion pairing, hydrogen boning, and molecular recognition.
In the current study, dependence of the probe conformations on the dispersive interactions at the aromatic edges between solvent and probes was tested by conformational distributions of the fluorinated derivatives (2b and 2c) of the probe molecule (1a). Solution and solid studies of these molecules put the previous conclusion drawn by the Cammers group in question. Current studies show that the dispersive interaction at the aromatic edge could not be the predominant force on the conformational changes in the probe molecule 1a during the fluoroalkanol perturbation. This study indicated that charges might be important in the formation of the folding conformations in the solution and solid state of 1a, 2b, and 2c. A contribution of this thesis was to prepare and study a conformational model that lacked charges. The previous molecules were charged.
The solid-state structures of pyridinium-derived aromatic rings from the CSD (Cambridge Structural Database) were studied to investigate the π-π interaction between cationic π-systems in solid state. Novel aromatic salt pairs of triangulene derivatives with the delocalized cation-anion interaction were synthesized to study the π-π interaction between two aromatic rings that carried opposite charges. This study showed that the interaction between ionic π-systems can be enhanced by cation-π and anion-cation attractions. The stackings of these π-systems introduce more overlap, closer packing and stronger atomic contact than that of the solid states of comparable neutral species. Cation-π and anion-cation attractions are synergistic in aromatic salts.
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Xia, You. "Experiments on EHD injection, interaction and electrocoalescence of water droplet pairs in oil." Thesis, Université Grenoble Alpes (ComUE), 2016. http://www.theses.fr/2016GREAI039/document.
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Lorsque des champs électriques sont appliqués à des mélanges eau-huile, les petites gouttelettes d'eau sont attirées entre elles et se regroupent en gouttes plus grosses. Ce processus d’électrocoalescence rend plus efficace la séparation huile-eau par sédimentation.Des données expérimentales sur l’électrocoalescence de très petites gouttelettes sont nécessaires pour améliorer la compréhension de la dynamique de l'interface eau-huile et pour valider les modèles numériques. La configuration simple étudiée dans ce travail de thèse concerne une petite paire de gouttelettes tombant dans une cuve d'huile modèle et soumise à un champ électrique aligné avec l’axe de symétrie des gouttes et la gravité.La première partie du travail a consisté à générer de façon contrôlée d’une paire de très petites gouttelettes (dans la gamme de diamètres 20-200 microns) alignée avec le champ électrique. La génération de goutte à la demande, par méthode éléctrohydrodynamique (EHD) a été améliorée pour un meilleur contrôle du diamètre et de la charge électrique des gouttelettes injectées à partir d'une aiguille métallique unique. Ceci a été obtenu en appliquant à un ménisque d'eau pendant à l’extrémité de l’aiguille des impulsions électriques de forme optimisée.La caractérisation électrique et hydrodynamique des paires de gouttelettes et leur coalescence sont alors principalement déduites de l'analyse des vitesses de chute, avec et sans application d’un champ électrique à courant continu. Des données complètes de positions des gouttelettes et de leur vitesse en fonction du temps sont déduites de prises de vues vidéo. Une attention particulière a été accordée aux visualisations de très petites gouttelettes tombant à petites vitesses, associant des angles multiples de prise de vue, de forts zooms et des vidéos à grande vitesse.La modélisation des différents termes d'interactions hydrodynamiques et électrostatiques entre les gouttelettes permet de déduire des vitesses enregistrées leur masse charge électrique respectives. Quand se produit une coalescence des deux gouttelettes, un enregistrement de la vitesse de la gouttelette résultante, avec et sans tension électrique appliquée, permet de contrôler la conservation de la masse et de la charge électrique, et la validation du procédé.Un premier ensemble de données est constitué d'environ 70 cas différents, avec différentes paire des gouttelettes (dans une plage de diamètre limitée de façon à ce que les vitesses de chute soient comprises entre 0,1 et 0,3 mm/s) et en faisant varier la tension appliquée à courant continu ou alternatif. L'analyse des résultats et des incertitudes expérimentales et un exemple de comparaison possible avec des simulations numériques utilisant le logiciel Comsol Multiphysics ™, permettent d'effectuer des recommandations pour les travaux futurs.Ce travail a été financé par le projet “Fundamental understanding of electrocoalescence in heavy crude oils”; coordonné par SINTEF Energy Research. Le projet a été soutenu par The Research Council of Norway, dans le cadre du contrat n °: 206976 / E30, et par les partenaires industriels suivants: Wärtsilä Oil & Gas Systems AS, Petrobras et Statoil ASAWhen electric fields are applied in oil-water mixtures small water droplets are attracted to others and merge in larger drops. This electrocoalescence process makes more efficient the oil-water separation by sedimentation.Experimental data on the electrocoalescence of very small droplets will be useful to improve the understanding of the dynamics of water-oil interface and to validate numerical models. The simple configuration studied consists in a small droplet pair falling in stagnant model oil, under electric field aligned with the symmetry axis of the droplet pair and the direction of gravity.First part of the work consisted in the well-controlled generation of very small droplet pair (range 20-200 microns) aligned with electric field. Droplet-on-Demand generation by EHD method was improved for a better control of the diameter and electric charge of droplets injected from a single metallic needle. This was obtained by applying to a pendant water meniscus optimized multistage high voltage electric pulses.Electrical and hydrodynamic characterization of the droplet pairs and their coalescence are then mainly deduced from the analysis of falling velocities, with and without applied DC electric field. A complete data set of droplet position and velocity is deduced from video. A special attention was paid to the visualizations of very small droplet and small falling velocities, involving multiple angle of view, strong zooming and high speed video.Modelling the different terms of hydrodynamic and electrostatic interactions between droplets allows deducing from the recorded velocities their respective mass and electric charge. When coalescence occurs, a record of the resulting single droplet velocity, with and without applied voltage, allows controlling the mass and charge conservations and validating the method.A first data set was constituted of about 70 different cases, with varying droplets pair (with a limited diameter range to remain with falling velocities between 0.1 and 0.3 mm/s) and varying applied DC or AC voltage. Analyses of the results and experimental uncertainties, and example of possible comparison with numerical simulations using Comsol Multiphysics™ software, allow performing some recommendations for future work.This work was funded by the project “Fundamental understanding of electrocoalescence in heavy crude oils”; co-ordinated by SINTEF Energy Research. The project was supported by The Research Council of Norway, under the contract no: 206976/E30, and by the following industrial partners: Wärtsilä Oil & Gas Systems AS, Petrobras and Statoil ASA
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MICHELON, MONIQUE. "Polyoxotungstates formes a partir d'heteroelements possedant une paire d'electrons libre : sb(3+) et bi(3+). interactions avec le cytochrome c." Paris 6, 1995. http://www.theses.fr/1995PA066399.
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Deux familles de composes de rapport sb(iii) ou bi(iii) / w variable ont ete obtenus par synthese, leurs analyses ainsi que leur comportement chimique et electrochimique ont ete etudies. Les composes x#2w#2#2o#7#6h#2#1#2#-(x = sb, bi), peuvent jouer le role de ligands des metaux de transition, ils conduisent aux complexes m#2#n#+(h#2o)#6x#2w#2#0o#7#0#(#1#4#-#2#n#)#-. La structure a ete resolue par diffraction des rayons x pour rb#1#2sb#2w#2#2o#7#6h#2 et na#1#0sb#2w#2#0v#2o#7#6h#2. Les composes m#n#+sb#9w#2#1o#8#6#1#8#- ont ete obtenus, ce sont les premiers cryptates inorganiques synthetises. La cavite cryptante peut etre occupee par des cations m#n#+, alcalins tels que na#+, k#+ ou alcalino-terreux tels que ca#2#+, sr#2#+ dont les rayons ioniques sont compatibles avec la taille de la cavite. Le compose nh#4#1#8nasb#9w#2#1o#8#6 connu sous le nom d'hpa 23 possede des proprietes antivirales. Cette etude a permis de mettre en evidence le role joue par l'heteroelement: sb(iii) ou bi(iii) possedent une paire d'electrons libre, qui oriente le processus de condensation des groupements tungstiques autour d'eux. Les interactions d'une hemoproteine, le cytochrome c, avec des heteropolyanions choisis en fonction de leur taille, de leur charge et de leur stabilite a ph voisin de 7 correspondant a celui des milieux biologiques, ont ete etudiees. Des complexes de stoechiometrie 1/1 analogues a ceux connus avec des molecules biologiques telles que la cytochrome oxydase ou le cytochrome bc#1 ont ete obtenus. Les caracteristiques de ces complexes dependent de l'heteropolyanion, de la force ionique et/ou du ph. Les resultats obtenus montrent que l'effet de taille de l'heteropolyanion est important mais que l'effet de charge est preponderant, comme dans les interactions entre des proteines et les acides nucleiques
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Le, Bihan Serge. "Le rôle de l'observation des pairs au cours de séances d'éducation physique et sportive." Thesis, Bordeaux, 2014. http://www.theses.fr/2014BORD0138/document.
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Une des spécificités des apprentissages dans le domaine des pratiques corporelles est leurvisibilité. Les comportements des élèves sont visibles et observables par tous les « consociés »(Schütz, 2008). L’objet de notre travail de recherche est d’étudier cette activité d’observationdes élèves entre eux pendant les séances d’éducation physique et sportive. Nous supposonsque cette expérience vicariante (Bandura, 1980, 2003) intervient dans le processus de corégulationdes apprentissages (Allal, 2007) des élèves. Les organisations matérielles etsociales et les activités physiques enseignées constituent le « donné » de l’enseignant (Béguin& Clot, 2004), l’environnement « imposé » (Carré, 2004) à travers les situationsd’apprentissage. Ils placent les élèves dans une certaine objectivité de l’environnement setraduisant par une prégnance exercée sur les apprenants. Ce créé, à la fois collectif etindividuel, est la source d’un savoir partagé (Bruner, 2008), d’un référentiel commun(Wenger, 2008) par la négociation (Gearing, 1984). Il constitue une transmission cachée.Cette activité recouvre les apprentissages moteurs, les comportements sociaux et le degréd’engagement des élèves dans les tâches. Les recueils ethnographiques sous la forme devidéos et d’entretiens d’auto-confrontation mettent en évidence des fonctionsd’acquisition/instrumentale, des fonctions relationnelles/de communication et des fonctionsmotivationnelles de cette expérience vicariante. Mais l’âge des élèves et les types d’activitésphysiques (jeu et sports collectifs/activités de sauts) influencent les effets de ces troisfonctionsOne of the special features of the learning process in the field of physical practises is itsvisibility. The pupil's behaviors are visible and observable by everyone involved. The aim ofour research is to study this observational activity in the students amongst themselves, duringthe physical education lesson. We suppose that this vicarious experience (Bandura, 1980,2003) plays a role in the co-regulatory process of the pupil's learning (Allal, 2007). Thematerial and social structures and the physical activities taught represent «the given» from theteacher (Béguin & Clot, 2004), the environment «imposed» (Carré, 2004) throughout thelearning situations. It puts the children in a certain environmental objectivity. The « creation »which is both collective and individual, is the source of a shared knowledge (Bruner, 2008), ashare repertoire (Wenger, 2008) through the negotiation. It establishes hidden transmission.This activity integrates motor learnings, social behaviors, and the students' level ofinvolvment in the tasks. Ethnographic data collections, in the form of video and self-analysisinterviews highlight the functions of acquisition, communication and motivation in thisvicarious experience. But the age of the pupils and the types of physical activities (team gameand sport/jumping activities) influences the effects of these three functions
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Kucher, Inna. "Search for the Higgs boson decaying to two photons and produced in association with a pair of top quarks in the CMS experiment." Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLS181/document.
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Dans cette thèse, la mesure des propriétés du boson de Higgs dans le canal de désintégration en deux photons avec l'expérience CMS au Grand Collisionneur de Hadrons (LHC) est présentée. L'objectif de ce travail est l’étude du mode de production associé à une paire de quark top (tṫH). Ce mode représente le seul accès direct au couplage de Yukawa du quark top, un paramètre fondamental du Modèle Standard. Le mode de production tṫH est un processus très rare. Il est de l'ordre de deux ordres de grandeur plus petits que la production principale du boson de Higgs par fusion de gluons. À 13 TeV, le mode de production ttH est environ 4 fois plus grand qu'à 8 TeV. Cette thèse reprend les études réalisées à 8 TeV, où l’échantillon de données ne suffisait pas pour établir une observation de ce mode de production. Bien que le canal en deux photons ne soit pas celui qui présente le plus grand rapport de branchement (seulement 0,2%), il est très prometteur en raison de son excellente résolution en masse (1%). De plus, sa signature est très propre dans le détecteur. Le canal de désintégration en deux photons est particulièrement intéressant puisqu'il s'agit du seul canal permettant l'étude de tous les modes de production : la fusion de gluons, la fusion de bosons vecteurs, les productions associées avec des bosons W ou Z ou avec une paire de quarks top. Le document commence par une introduction théorique du Modèle Standard et la physique du boson de Higgs au LHC, suivie d'une description du détecteur CMS. Pour obtenir une excellente résolution de masse dans le canal de désintégration en deux photons , le calorimètre électromagnétique doit être calibré. Le système de monitorage de la transparence des cristaux du calorimètre électromagnétique de CMS par le système laser joue un rôle important dans la chaîne d'étalonnage et est décrit en détail. Sur le long terme, le système de monitorage laser devra être amélioré car le niveau de rayonnement influence son électronique. Je présente mon travail sur l'amélioration possible du système de monitorage laser, ainsi que l'étude de sa précision possible. L'analyse inclusive H → ᵞᵞ a eu plusieurs itérations pour les conférences en 2016 et 2017. La stratégie pour 2017 est décrite dans ce document. Une classification des événement sert à maximiser la significance du signal et à étudier les modes spécifiques de production du boson de Higgs. Mes contributions à l'analyse H → ᵞᵞ consistent en l'identification du vertex primaire, l'identification du photon et l'étude du mode de production tṫH. Chaque contribution est décrite en détail dans des chapitres dédiés. L'analyse tṫH, H → ᵞᵞ est présentée pour deux itérations en 2016 et 2017, en mettant l'accent sur les améliorations dans l'analyse de 2017. Enfin, les résultats de l'analyse inclusive et tṫH, H → ᵞᵞ, en utilisant l'ensemble complet de données 2016 correspondant à une luminosité intégrée de 35,9 fb-1, sont présentésIn this thesis, the measurement of the Higgs boson properties in the diphoton decay channel with the CMS experiment at the Large Hadron Collider (LHC) is presented. The focus of this work is the tṫH production mode, as it is the only direct access to the top quark Yukawa coupling, a fundamental parameter of the Standard Model. tṫH is a very rare process, two orders of magnitude smaller than the dominant Higgs boson production by gluon fusion. At 13 TeV, ttH production is about 4 times larger than at 8 TeV. This thesis takes over the studies performed at 8 TeV, where the statistics was not enough for an observation of ttH. Despite a very small branching ratio (only about 0.2%), the two photons decay channel of the Higgs boson is very promising, because of its excellent mass resolution (about 1%). Moreover, its signature in the detector is very clear. The diphoton decay channel is also of particular interest as it is the only channel allowing the study of all production modes: gluon fusion, vector boson fusion, associated productions with a W or a Z bosons, or with a top quark pair.The document starts with a theoretical introduction about the Standard Model and Higgs boson physics at LHC, followed by a description of the CMS detector. To achieve an excellent mass resolution in the H → ᵞᵞ channel, the electromagnetic calorimeter has to be calibrated. The laser monitoring system plays an important role in the calibration chain and it is described in details. On the long term, the laser monitoring system will have to be upgraded as level of radiation influences its electronics. I present my work on the possible upgrade of the laser monitoring system, along with the study of its possible precision.H → ᵞᵞ inclusive analysis had several iterations for conferences in 2016 and 2017. The strategy for 2017 is described in this document. An event classification is used to maximize the signal significance and to study specific Higgs boson production modes. My contributions to the H → ᵞᵞ analysis are primary vertex identification, photon identification and the study of the tṫH production mode. Each contribution is described in details in dedicated chapters. The tṫH, H → ᵞᵞ analysis is shown for two iterations in 2016 and 2017, with the emphasis on improvements in 2017 analysis. Finally, the results of the inclusive and tṫH, H → ᵞᵞ analysis, using the full 2016 dataset corresponding to an integrated luminosity of 35.9 fb-1, are shown
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Fraisse, Jacques. "Interactions sociales entre pairs et découverte d'une stratégie cognitive chez des enfants de 11 ans." Lille 3 : ANRT, 1987. http://catalogue.bnf.fr/ark:/12148/cb37594745x.
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Milovanovic, Milan. "Experimental and theoretical approaches coupled with thermochemistry of reactions in solution and the role of non-covalent interactions." Thesis, Strasbourg, 2018. http://www.theses.fr/2018STRAF049.
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Ce manuscrit aborde plusieurs interactions / réactions chimiques importantes se produisant dans la soluton en utilisant la calorimétrie par titrage isothermique (ITC) et la théorie de la densité fonctionnelle statique (DFT). Cette thèse porte son attention notamment sur : l'association de paires de Lewis (frustrées) ((F)LPs), la migration cis du groupe méthyle au sein du pentaméthylmanganèse induit par les phosphines, l'aminolyse de carbènes de Fischer, l'insertion d'alcynes dans des palladacycles, l'affinité de divers donneurs de Lewis à l’hexafluoroisopropanol. L'ITC s'est révélé être une technique expérimentale puissante pour obtenir des données thermochimiques fiables sur les systèmes étudiés. Les calculs statiques DFT-D ont montré une capacité d’estimation correcte des paramètres de réaction thermodynamique lorsque l’influence de la solvatation n’est pas significative. Autrement, lorsque l’influence du solvant est apparente, les calculs ne permettent pas de reproduire les résultats expérimentaux. En plus, les résultats expérimentaux et théoriques révèlent l’existence d’ensembles moléculaires plus grandes dans la solution de FLP, soulignant le rôle des interactions non covalentesThis manuscript adressed several important chemical interactions/reactions taking place in solutuon by using Isothermal Titration Calorimetry (ITC) and static Density Functional Theory (DFT). Namely, this thesis dealt with: association of (frustrated) Lewis pairs ((F)LPs), cis-migration of methyl group within pentamethylmanganese induced by phosphines, aminolysis of Fischer carbenes, insertion of alkynes into palladacycles, affinity of various Lewis donors to hexafluoroisopropanol. The ITC proved to be powerful experimental technique for obteining reliable thermochemical data of sutudied systems. The static DFT-D calculations showed capability for proper estiamtion of thermodynamic reaction parameters when an influence of solvation is not sighnificant. Otherwise, when the influence of solvent is not innocent, the calculations moslty failed to reproduce the experimantal results. In addition, Both the experimantal and therortical results revield existance of larger molecular clusters in solution of FLPs emphasising a role of non-covalent interactions