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1
Canot, Clotilde. "Détecteur optique Cherenkov de photons 511 keV, rapide et efficace, pour l’imagerie TEP." Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLS190/document.
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La Tomographie par Emission de Positrons (TEP) est une technique d’imagerie médicale utilisée largement dans le traitement du cancer et dans la recherche neurobiologique, afin d’imager l’activité biologique des organes. Il s’agit de détecter deux photons de 511 keV produits par l’annihilation d’un positron dans les tissus, ce qui permet d’en reconstruire la carte 3D. En mesurant avec une très bonne précision la différence de temps de détection des deux photons, il sera possible d’améliorer la qualité d’image (technique du temps de vol). Dans ce manuscrit, nous présentons le développement de deux détecteurs innovants, rapides et efficaces, pour la détection de la lumière Cherenkov produite par la conversion des photons de 511 keV. Le premier, destiné à un scanner clinique (cerveau) et pré-clinique à haute précision spatiale, utilise comme milieu de détection du TriMéthylBismuth. Le second, pouvant être utilisé pour construire un scanner corps entier, met en œuvre un cristal de PbF₂ comme radiateur Cherenkov. Dans les deux configurations, un photomultiplicateur à micro-canaux (MCP-PMT) est utilisé pour détecter les photons Cherenkov. Notre électronique de détection montre une résolution temporelle limitée à 5 ps (RMS). La chaîne de détection est limitée par les performances du MCP-PMT. Après étalonnage, nous avons mesuré une efficacité de 25 % (grande pour un détecteur Cherenkov), et de résolution temporelle de 200 ps (FWHM).Nous exposons les facteurs limitant la résolution temporelle des détecteurs et proposons des développements qui permettront d’en améliorer les performancesPositron Emission Tomography (PET) is a nuclear imaging technique widely used in oncology and neuroscience to observe biological activity in the body. Detection of two gamma quanta with the energy 511 keV emitted by positron annihilation in tissues allows one to reconstruct the tracer activity distribution in the body of the patient. Additional measurement of the difference in time detection between the two photons lets us to improve significantly the quality of the reconstructed image (time-of-flight method).In this manuscript, we present the development of two innovative detectors, fast and efficient, used to detect Cherenkov light produced by electrons from the photo-ionization conversions of 511 keV gamma quanta. The first one, intended for use in a brain PET scanner of a high spatial resolution, uses TriMethylBismuth for the detection medium. The second one, planned to be used to construct a whole-body PET scanner, enforces a PbF₂ crystal as Cherenkov radiator. In both configurations a micro-channel photo-multiplier (MCP-PMT) is used to detect Cherenkov photons. We commissioned an electronic detection chain with a time resolution limited to 5 ps (RMS). Using precise MCP-PMT calibration, we were able to develop simultaneously detectors with high efficiency, up to 25 %, and time resolution as good as 200 ps (FWHM).We highlight the limitations of detectors time resolution and suggest several developments in order to improve performances of Cherenkov light detectors
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Vieira, Patrícia Isabel dos Santos. "Determinação dos erros de medição associados ao ensaio PMT." Master's thesis, Universidade de Aveiro, 2009. http://hdl.handle.net/10773/2729.
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Mestrado em Engenharia GeológicaO dimensionamento de estruturas em engenharia tem a sua base assente no cálculo. Como tal torna-se fundamental o conhecimento da eficiência e da qualidade dos resultados. A obtenção dos parâmetros geotécnicos utilizados é baseada em ensaios in situ, e o seu cálculo depende da qualidade dos equipamentos de medição, da adequabilidade a cada situação e dos erros associados a cada um dos parâmetros. A dissertação apresentada baseia-se na análise de sensibilidade dos equipamentos de medição do ensaio Pressiómetro de Ménard, PMT a fim de verificar a qualidade da precisão associada e suas consequências no cálculo dos parâmetros geotécnicos de caracterização de maciços. ABSTRACT: The size of structures in engineering has its basis based on the calculation. As such it is fundamental knowledge of the efficiency and quality of results. The attainment of the geotechnical parameters used is based on testing in situ, and its calculation depends on the quality of measuring equipment, the adequacy of each situation and the errors associated with each of the parameters. The graduation work presented is based on the analysis of sensitivity of measuring equipment for the pressuremeter test, PMT to verify the quality of precision and their associated consequences in the calculation of geotechnical parameters for the characterization of soils.
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María, C. Córdoba Llamas. "Selección de Personal basada en la misión: Prosocial Motivation Test (PMT)." Doctoral thesis, Universitat Internacional de Catalunya, 2017. http://hdl.handle.net/10803/565507.
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Las personas y su motivación son la clave de éxito de las empresas. Para que una empresa pueda mantenerse en un mundo globalizado de cambios continuos y alta competitividad es necesario que cuente con las personas adecuadas, ya que el capital humano se ha convertido en el capital más importante de las empresas, su capital diferencial. Pero, ¿qué quiere decir las “personas más adecuadas”? Revisando la bibliografía, se observa que las respuestas a esta pregunta responden a una preocupación tan antigua como la humanidad, y que han ido cambiando a lo largo de la historia. Seleccionar a las personas más adecuadas ha sido y sigue siendo un tema de gran interés en la actualidad, no resuelto en su totalidad.
Frente al reto de seleccionar a las personas más adecuadas, en esta investigación se concluye la necesidad de considerar el compromiso de las personas con la misión. Esta conclusión se apoya en la necesidad de integrar la misión en los sistemas de gestión (Bart, 1997), así como en el modelo tridimensional de la misión (Rey, 2016; Bastons et al., 2016) basado a su vez en el modelo organizacional antropológico (Pérez López, 1993). El modelo tridimensional de la misión establece que para que una misión sea efectiva necesita además de la dimensión formal (el qué) y la dimensión dinámica (el cómo), la dimensión motora o motivación prosocial (Grant, 2008) que sería el motor de las anteriores. La motivación prosocial corrige en parte el “fallo de la misión” (Rey, 2016) o la falta de efectividad de la misión. Para generar el compromiso de los candidatos con la misión es necesario tener en cuenta la calidad motivacional de los candidatos en los procesos de selección, y más concretamente la motivación prosocial de las personas que formarán parte de las organizaciones. La motivación prosocial es aquella que tiene en cuenta las necesidades de los “otros” entre los que se encuentran los stakeholders, y por consiguiente la única motivación capaz de interiorizar la misión y de hacerla efectiva (Bastons et al., 2016).
Una vez detectada la necesidad de medir la motivación prosocial en los procesos de selección, surge un segundo reto para las organizaciones consistente en poder medir la misma. Revisando la bibliografía se comprueba que el paradigma antropológico relacionado con la escuela holista tiene como objetivo medir el compromiso de los colaboradores. El modelo de selección, caracterizado por el eclecticismo y el modelo psicosocial (Blasco, 2000) incorpora la medición del encaje persona-organización (P-O) en los procesos de selección. A pesar de la escasa bibliografía acerca de las técnicas de selección utilizadas para medir el encaje P-O, en la literatura se señala la entrevista estructurada como la técnica de selección por excelencia, en combinación con diferentes técnicas que miden, entre otros aspectos, elementos cercanos a la motivación prosocial. Se pueden encontrar test de valores, test de motivaciones, test de competencias socio-personales (que incluye el comportamiento prosocial), y test de personalidad que miden aspectos como la estabilidad emocional o integridad, entre otros. Pero no se ha encontrado ninguna técnica que mida la calidad motivacional del candidato y más concretamente el peso de la motivación prosocial que permitirá una mayor conexión con la misión. Para dar respuesta a este segundo reto se propone el PMT (Prosocial Motivation Test) como técnica válida para detectar el peso de la motivación prosocial con respecto al resto de motivaciones también presentes en los candidatos, como son la motivación intrínseca y extrínseca. Por último, en el análisis que trata de determinar las relaciones entre las variables personales de edad, género y nivel jerárquico, y la motivación prosocial, se concluye con resultados contradictorios que van en línea con los estudios hallados en la literatura.
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Chen, Yingtao. "Simulations and electronics development for the LHAASO experiment." Thesis, Paris 11, 2015. http://www.theses.fr/2015PA112147/document.
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Le travail de thèse porte sur l'étude de l'électronique front-end pour le télescope WFCTA (Wide Field of View Cherenkov Telescope Array,) qui est l'un des détecteurs de l’observatoire LHAASO (Large High Altitude Air shower Observatory,). Le manuscrit de thèse couvre six thèmes principaux allant de la simulation physique au développement d’un nouveau système d'acquisition de données.Tout d'abord, les principes de la physique des rayons cosmiques et de l'expérience LHAASO sont présentés donnant ainsi une introduction sur les sujets discutés dans la thèse. Des simulations ont été faites dans le but de comprendre la propagation des rayons cosmiques dans l'atmosphère et d’en déduire les caractéristiques du signal d'entrée de l'électronique. Ces simulations ont également été utilisées pour approfondir la compréhension des spécifications du télescope et de les vérifier.Un nouveau modèle de PMT a été élaboré pour être utilisé dans les simulations. Ce nouveau modèle est comparé aux autres modèles de PMT. Des modèles d’électronique pour les conceptions basées sur les composants électroniques classiques et sur l’ASIC (Application-specific Integrated Circuit) sont construites et étudiées. Ces deux solutions remplissent les spécifications du télescope WFCTA. Néanmoins, compte tenu du développement de la micro-électronique, il est proposé que l’électronique des télescopes de haute performance devrait être basée sur l’ASIC.L'ASIC sélectionné, PARISROC 2, est évalué en utilisant des bancs de tests existants. Les résultats montrent que ces bancs de tests ne peuvent pas démontrer pleinement la véritable performance de l’ASIC. Par conséquent, une carte électronique front-end prototype qui est basée sur ASIC a été conçu et fabriqué. Plusieurs modifications ont été apportées pour améliorer la performance de la nouvelle carte. Une description détaillée de ce développement est présentée dans la thèse. Un nouveau système d’acquisition de données a également été conçu pour améliorer la capacité de lecture de données dans le banc de tests de la carte front-end.Enfin, une série de tests ont été effectués pour vérifier le concept de design et pour évaluer la performance de la carte front-end. Ces résultats montrent la bonne performance générale de l'ASIC PARISROC 2 et que la carte front-end répond globalement aux spécifications de la WFCTA. Basé sur les résultats de ce travail de thèse, un nouveau ASIC, mieux adapté pour les télescopes de type WFCTA, a été conçu et est actuellement en cours de fabricationThis thesis is focused on the study of the front-end electronics for the wide field of view Cherenkov telescope array (WFCTA), which is one of the large high altitude air shower observatory (LHAASO) detectors. The thesis manuscript covers six main topics going from the physics simulations to the implementation of a new data acquisition system. The physics of cosmic rays and the LHAASO experiment is presented giving foundation for discussion of the main topics of the thesis. Simulations were performed to understand the propagation of cosmic rays in the atmosphere and to determine the characteristics of the input signal of the electronics. These simulations allow also understand the specifications of the telescope and to verify them. A new PMT model was successfully built for both physical and electronic simulations. This new model is compared to other models and its performance is evaluated. Behavior models for the designs based on the classical electronics and application-specific integrated circuit (ASIC) were built and studied. It is shown that both solutions fit the requirements of the telescope. However, considering the development of the micro-electronics, it is proposed that the electronics of the high-performance telescopes should be based on ASIC. The selected ASIC, PARISROC 2, is evaluated by using the existing application boards. The results showed that the designs considered could not fully demonstrate the real performance of the chip. Therefore, a prototype front-end electronics board, based on PARISROC 2, was designed, implemented and fabricated. Several modifications and enhancements were made to improve the performance of the new design. A detailed description of the development is presented and discussed in the manuscript. Furthermore, a new data acquisition system was developed to enhance the readout capabilities in the front-end test bench.Finally, a series of tests were performed to verify the concept of the design and to evaluate the front-end board. The results show the good general performance of the PARISROC 2 and that this design globally meets the specifications of the WFCTA. Based on the results of this thesis work, a new ASIC chip, better adapted for telescopes such as WFCTA, has been designed and is currently being fabricated
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Giannini, Giulia. "Caratterizzazione di un rivelatore MCP-PMT per misure di risoluzione temporale e spaziale." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amslaurea.unibo.it/7291/.
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Questa tesi descrive una prima serie di misure effettuate per caratterizzare le prestazioni di un rivelatore di fotoni MCP-PMT a multi anodo, con particolare enfasi sulla risoluzione temporale e spaziale. I risultati sono stati confrontati con quelli relativi a tre ulteriori rivelatori (un MCP-PMT a singolo anodo e due fotomoltiplicatori a silicio). Le misure sono state effettuate presso i Laboratori dell’Istituto Nazionale di Fisica Nucleare (INFN - Sezione di Bologna) per conto del Dipartimento di Fisica dell’Università di Bologna.
La rivelazione della luce ha sempre occupato un posto fondamentale nella Fisica Nucleare e Subnucleare. Il principio base della rivelazione consiste nel trasformare la luce incidente in un segnale elettrico misurabile e i primi strumenti storicamente utilizzati furono i fotomoltiplicatori.
Successivamente furono introdotti dei nuovi rivelatori di fotoni chiamati Micro Channel Plates, composti da un array di canali di dimensioni microscopiche, ciascuno in grado di moltiplicare gli elettroni prodotti per effetto fotoelettrico dai fotoni incidenti. Questo nuovo modello presenta ottime prestazioni in particolare per quanto riguarda la risoluzione temporale, e questa insieme ad altre caratteristiche (come la segmentazione degli anodi, che permette una risoluzione spaziale migliore), ha spinto a studiarne il funzionamento.
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Bennich-Björkman, Oscar, and Anton Nyström. "The Backup-Plan : En kvantitativ studie om säkerhetskopiering bland studenter på Uppsala universitet." Thesis, Uppsala universitet, Institutionen för informatik och media, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-297582.
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Få personer säkerhetskopierar tillräckligt ofta, trots att de riskerar att förlora viktiga filer. Vad beror det på? Denna uppsats har genom en kvantitativ undersökning försökt klarlägga vilka faktorer som har störst påverkan på detta beteende och om det finns ett samband mellan dessa. Datainsamlingen skedde genom en enkätundersökning, med över 300 svar från olika studenter på Uppsala universitet. Resultaten analyseras med hjälp av det teoretiska ramverket “Protection Motivation Theory” (PMT) och jämförs sedan med liknande forskning. Resultaten visar att lättja och glömska är de två faktorer som respondenterna själva anser har störst påverkan. Utöver detta har även det studieprogram vilket studenten går på betydelse. Resultaten visar också att hur studenterna bedömer sannolikheten för dataförlust och graden av de problem som kan uppstå vid en dataförlust båda har ett positivt samband med hur ofta säkerhetskopiering utförs. Av dessa har uppskattat problem störst påverkan. Detta resultat skiljer sig från vad delar av tidigare forskningen har visat, men ligger i linje med vad PMT säger om detta beteende.Few people backup their files frequently enough, even though they risk losing important files. Why is this? This paper has through a quantitative survey attempted to elucidate which factors have the biggest impact on this behavior and if there is a correlation between these. The data was collected using a questionnaire which got over 300 answers from students at Uppsala University. The results were analyzed using the theoretical framework “Protection Motivation Theory” (PMT) and was then compared to similar research. The results show that laziness and forgetfulness are the two biggest factors that the respondents themselves say have the biggest impact on their behavior. In addition to this the kind of program the student is attending also has an effect. The results show that the assessed probability of losing data and the severity of the problem of losing data have a positive correlation with how often backup is done, where assessed problem has the biggest impact. These results differ from what some of the earlier research has shown, but is in line with what PMT says about this behavior.
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Heusch, Niklas. "Essays in development economics." Doctoral thesis, Universitat Pompeu Fabra, 2018. http://hdl.handle.net/10803/663490.
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This thesis combines three independent articles. In the first chapter, I examine the health care that drug sellers, common medical providers in many developing coun-tries, provide for childhood illness in Ghana, and study its determinants. Overall, I find the quality of treatment to be poor and provide evidence that this is caused by low knowledge of drug sellers, rather than low effort or adverse financial in-centives; a simulation exercise suggests that adequate treatment would not reduce drug sellers’ profits or increase clients’ expenditures.
In the second chapter, I examine rural-urban migration in Tanzania and pro-vide evidence of substantial selection into urban migration among residents of agricultural households: movers to urban areas are substantially better educated and more commonly participate in formal labour markets prior to moving. Ho-wever, changes to the economic situation of agricultural households have large impacts on this sorting to urban areas, suggesting that households’ ability to fi-nance migration might be an important bottleneck.
In the third chapter, I study the (recently debated) performance of proxy me-ans testing (PMT), an econometric approach deducing households’ poverty status from easily collectable information on household characteristics. Brown et al.(2016) criticise the performance of PMT; I find these results to be driven by mis-calibration: when calibrated to match the poverty rate of the population, PMT performs substantially better and, although far from perfect, might still provide useful information to its users.Esta tesis está compuesta por tres artículos independientes. El primer capítulo examina la atención sanitaria que los farmacéuticos, proveedores médicos muy comunes en algunos países en vías de desarrollo, proveen para enfermedades infantiles en Ghana y estudia los factores determinantes. Encuentro que la calidad de los tratamientos es baja y muestro evidencia de que esta´áausada por el bajo conocimiento de los farmacéuticos, y no por el bajo esfuerzo de éstos o la presencia de incentivos económicos perversos. Un ejercicio de simulación sugiere que el tratamiento adecuado no reduciría los beneficios de los farmacéuticos ni incrementaría los gastos de los clientes. En el segundo capítulo, examino la migración rural-urbana en Tanzania y proveo evidencia de la existencia de una selección sustancial en la migracióon urbana dentro de los residentes de los hogares agrícolas: aquellos que deciden mudarse aáreas urbanas son más educados y tienden a participar más en el mercado laboral antes de mudarse. Sin embargo, cambios en la situación económica de los hogares agrícolas tienen grandes impactos sobre la selección, sugiriendo que la habilidad para financiar la migración que tienen los hogares puede ser un obstáculo importante. En el tercer capitulo estudio el desempeño (debatido recientemente) del “proxy means testing” (PMT), un método econométrico que establece el estatus de pobreza de los hogares según un conjunto de información sobre las características de los hogares que se obtienen fácilmente. Brown et al. (2016) critican el desempeño del PMT; yo encuentro que estos resultados se deben a una calibración errónea: cuando la calibración se realiza para igualar la tasa de pobreza de la población, el PMT funciona mucho mejor y, aunque no es perfecto, puede seguir proveyendo con información útil a sus usuarios.
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Legigan, Thibaut. "Étude de systèmes moléculaires programmés pour le ciblage thérapeutique d'agents anticancéreux." Thesis, Poitiers, 2012. http://www.theses.fr/2012POIT2295/document.
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Malgré les efforts extrêmement importants réalisés pour la recherche de nouveaux agents anticancéreux, les traitements par chimiothérapie ne permettent toujours pas de traiter efficacement un grand nombre de tumeurs. En effet, les molécules utilisées cliniquement ne sont généralement pas sélectives des tissus cancéreux et la destruction des tissus sains qu'elles engendrent provoque de lourds effets secondaires. Le développement de nouvelles stratégies thérapeutiques plus sélectives représente donc un intérêt majeur en chimie médicinale. Dans ce cadre, nous avons développé plusieurs vecteurs non toxiques conçus pour reconnaître des spécificités liées à la malignité puis libérer de manière contrôlée des agents cytotoxiques exclusivement au niveau de la tumeur. Dans le cadre de cette thèse, le concept de vecteur glucuronylé a été adapté à la MMAE et à la cyclopamine. Ces vecteurs pourront être sélectivement activé par la B-glucuronidase présente en concentration importante dans les zones nécrotiques de nombreuses tumeurs solides et ainsi libérer ces agents anticancéreux au niveau des tissus cancéreux. Des études préliminaires visant à évaluer l'efficacité de ces composés in-vitro et in-vivo ont montré la validité de cette approche. Dans un deuxième temps, un vecteur glucuronylé de la doxorubicine pouvant se lier à l'albumine plasmatique a été conçu. Une étude réalisée chez la souris a montré que ce composé possède une efficacité thérapeutique similaire à celle de la doxorubicine et ne provoque pas les effets secondaires constatés lors du traitement avec la drogue seule. La troisième partie est consacrée au développement du premier vecteur activable par la B-galactosidase utDespite several years of intensive research devoted to the discovery of novel anticancer agents, chemotherapy is still not entirely effective for the treatment of many solid tumors. Most of the drugs used clinically act by anti-proliferative mechanisms and lack any intrinsic selectivity, leading to severe adverse effects due to the destruction of normal tissues. Therefore, the development of more selective therapeutic approaches has become a major goal in medicinal chemistry. Within this framework, we have developed several nontoxic drug carriers designed for both the efficient recognition of malignant specificities and the controlled release of anti-neoplastic agents exclusively at the tumour site. First, we applied the concept of glucuronide prodrugs to MMAE and Cyclopamine in order to deliver these anticancer drugs at the tumor site. Indeed, glucuronide prodrugs can be selectively activated by B-glucuronidase present in high concentration in necrotic area of numerous solid tumors. Preliminary in vitro and in vivo evaluations of these prodrugs demonstrated the potential of this approach. Second, we studied the first B-glucuronidase-responsive albumin-binding prodrug designed for the selective delivery of doxorubicin at the tumor site. In vivo experiment conducted in mice show that this compound inhibits tumor growth in a similar manner to doxorubicin whilst avoiding side effects induced by the free drug. We also developed the first B-galactosidase-responsive drug delivery system suitable for the treatment of solid tumors in PMT. Such a targeting system can be selectively activated by lysosomal B-galactosidase located inside malignant cells expressing a specific tumor-a
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Hultman-Boye, Tove. "Ungdomars, ledares och föräldrars upplevelser av 'KOMET för föräldrar till ungdomar 12-18 år'." Thesis, Stockholm University, Department of Psychology, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-7660.
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Kometprogrammet började utvecklas 2001 och är en svensk variant av nordamerikanska manualbaserade föräldraträningsprogram. Varianten Komet 12-18 år riktar sig till föräldrar med utagerande ungdomar med syftet att bryta negativa beteendemönster genom att ändra föräldrarnas förhållningssätt till sina barn. Grundtankarna är hämtade från inlärningsteori, beteendeanalys, prevention och kognitiv beteendeterapi och bygger på evidensbaserad forskning. Syftet med studien är att bidra till utvecklingen av Komet 12-18 år och tillgodose ungdomsperspektivet med resultat från ungdomsintervjuer och –enkäter. Frågeställningen är om ungdomarna själva upplever någon förändring i sina föräldrars beteende och i så fall vilken efter genomgånget program. Ledarnas och föräldrarnas åsikter om programmet sammanfattas utifrån en enkätundersökning. Antalet deltagare blev lägre än väntat. Komets övergripande mål, att minska bråk och förbättra kommunikationen hemma, uppfylldes enligt de medverkande ungdomarna i genomsnitt men ungdomarna uttryckte sig försiktigare än både ledare och föräldrar angående förbättringen. Hos dem där förändring skett uppfattades den positivt och ungdomarna uppskattade ansträngningen från föräldrarna som främst mammorna stod för.
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Boast, Kathryn. "A position-sensing system for the top PMT array in the LUX-ZEPLIN dark matter experiment." Thesis, University of Oxford, 2017. http://ora.ox.ac.uk/objects/uuid:1d0feedb-e335-4ea6-9420-ac3c28f3dcd2.
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LUX-ZEPLIN (LZ) is a next-generation liquid xenon dark matter detection experiment, searching for direct interactions with WIMPs. As it is a low-background experiment using high-purity xenon, the sensors installed to monitor the experiment must be custom-made from a short list of acceptable materials. This includes the position sensors that will monitor the relative position of the top photomultiplier tube (PMT) array with respect to the cryostat vessel that surrounds it. LZ will operate at around -100°C, so must undergo a significant cooling period, during which the vessel that supports the PMT array is expected to shrink. It is crucial to monitor this. The capacitive position sensors couple a change in relative position to a change in capacitance. However, the size of the LZ detector necessitates the use of cables around 12m long to read out this signal. These cables will have a capacitance themselves of around 1 nanofarad, which can vary as the cable environment changes, while the sensor capacitances are around a thousand times smaller, so small variations in the cable capacitance could be misinterpreted as changes in position. To combat this, we created a novel feedback circuit for the sensor readout electronics, designed to suppress the effect of the cable capacitance. To monitor precisely the position of the PMT array with respect to the cryostat vessel, we will use six position sensors mounted as a Gough-Stewart Platform Mechanism (GSPM) between the PMT truss and the cryostat vessel. The use of six sensors in this configuration will enable the reconstruction of all six degrees of freedom of the position of the PMT array. I have developed an algorithm that returns these six values given input from the position sensors. The six capacitive sensors connected as a GSPM, with the novel readout electronics, form the system of position sensors that will be used in the LUX-ZEPLIN experiment.
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Rodrigues, Ge?rgia Cristiane. "BYOD como pol?tica de seguran?a em uma empresa: uma an?lise ? luz da PMT." Universidade Federal do Rio Grande do Norte, 2015. http://repositorio.ufrn.br/handle/123456789/20412.
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O avan?o da tecnologia m?vel, no que diz respeito ? disponibilidade de servi?os 3G/4G e da utiliza??o de Dispositivos como Smartphones e Tablets originou um novo fen?meno de comunica??o: BYOD (Bring Your Own Device), ? uma nova tend?ncia de neg?cios, onde os funcion?rios est?o utilizando seus pr?prios dispositivos para fins de trabalho. A r?pida expans?o de BYOD e as quest?es de seguran?a e privacidade de dados representam desafios significativos para as organiza??es. A resposta mais comum a essas preocupa??es ? a ado??o de pol?ticas corporativas que regem BYOD. Este estudo tem por objetivo analisar a inten??o dos funcion?rios em cumprir com a pol?tica de seguran?a da organiza??o no contexto de BYOD, quando os funcion?rios utilizam seus dispositivos pessoais para acessar recursos organizacionais para realizarem o trabalho, dentro ou fora do ambiente organizacional. Para tanto, foi utilizada a Teoria de Motiva??o a Prote??o (TMP) como embasamento te?rico. Em termos metodol?gicos, a presente pesquisa, ? do tipo descritiva e tamb?m explorat?ria com uma abordagem quantitativa. N?o aleat?ria ? o tipo de amostragem. Para coleta, foi aplicado um question?rio estruturado, tipo survey, com um conjunto de itens de medi??o para cada construto. A etapa de an?lise dos dados foi realizada por meio de utiliza??o de t?cnicas de estat?stica descritiva e an?lise multivariada, tais como a An?lise Fatorial Explorat?ria (AFE) e a Regress?o Linear M?ltipla (RLM). Do ponto de vista te?rico, os resultados demonstram que o modelo PMT fornece uma base te?rica s?lida para a investiga??o nesta ?rea. No entanto, os resultados tamb?m indicam que este modelo ? afetado por fatores contextuais, e que a escolha da amostra pode influenciar a import?ncia dos diferentes componentes do modelo. Portanto, o cuidado deve ser tomado na generaliza??o desses resultados para outros contextos e popula??es
The advancement of mobile technology, with regard to the availability of 3G / 4G and use of devices such as Smartphones and Tablets yielded a new communication phenomenon: BYOD (Bring Your Own Device), is a new business trend, where employees are using their own devices for work purposes. The rapid expansion of BYOD , data security and privacy issues pose significant challenges for organizations. The most common response to these concerns is the adoption of corporate policies governing BYOD. This study aims to analyze the intention of employees to comply with the organization's security policy in the context of BYOD, when employees use their personal devices to access organizational resources to develop work related tasks, inside or outside the organizational environment. Therefore, we will use the Motivation Theory Protection as theoretical basis. In terms of methodology, this research will be a descriptive and exploratory study with a quantitative approach. Nonrandom will be the type of sampling. For collection, a structured questionnaire, survey type, with a set of measurement items for each construct is applied. The data analysis step is performed by means of descriptive statistics, Exploratory Factor Analysis and Multiple Linear Regression. From a theoretical point of view, the results demonstrate that the PMT model provides a solid theoretical basis for research in this area. However, the results also suggest that this model is affected by contextual factors, and the selection of the sample may influence the importance of the different components of the model. Therefore, caution should be taken in generalizing these results to other settings and populations.
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Postell, David Jonathan. "Laser Induced Fluorescence Spectroscopy of molecular bromine: Observations of Emission to High Vibrational Levels in the Ground (X) State." Wright State University / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=wright1186777955.
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Hompis, George-Sigfrid. "Studentens Krisberedskap efter MSBs informationsblad." Thesis, Karlstads universitet, Institutionen för hälsovetenskaper (from 2013), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-75406.
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Samhället står inför olika typer av kriser men medborgarna verkar inte vara förberedda. Kommuner och andra myndigheter spelar en stor roll för invånarnas säkerhet, när en kris inträffar samtidigt som invånarna har ett eget ansvar, gällande förberedelser inför potentiella kriser. MSB fick år 2018 i uppdrag av regeringen, att distribuera en broschyr till allmänheten med syfte att öka medborgarens kunskap kring krisberedskap. Broschyren skulle fungera som ett verktyg för medborgare gällande eget ansvar vid en krissituation. Denna uppsats kommer därför att handla om studenters krisberedskap och vilka faktorer som påverkar denna inför en potentiell kris. Data har samlats in genom att intervjua studenter som har fått broschyren och datamaterialet har analyserats med kvalitativ innehållsanalys. I resultatet framgick att broschyren inte hade en nämnvärd påverkan av studenternas intresse av införskaffande av material för beredskap däremot hade studenterna påverkats och börjat tänka på beredskap och kriser. Information spelar en viktig roll för studenternas beredskap, och det finns kunskap hos studenterna gällande vilket eget ansvar de har om en kris skulle inträffa. Det huvudsakliga ansvaret ligger enligt studenterna på myndigheter och andra organ för medborgarnas säkerhet men även information som skickas till allmänheten. Dock anser studenterna att medborgare bär ett eget ansvar för att ta del av informationen från kommuner och myndigheter. Enligt studenterna bör det finnas ett samspel mellan individer och övriga organ. Studenterna anser också att information behöver inhämtas från flera olika källor av massmedia för att kunna få en korrekt övergripande bild av en händelse. Studenternas omgivning är en del som påverkar studentens krisberedskap då familj och vänner kan påverka studenter gällande beredskap. Hantering av mediciner är något som poängterades att broschyren saknade. Vissa mediciner behöver hållas kylda och därför anses möjliga sätt att hantera frågan särskilt viktig. Studenterna menar att broschyren hade behövt gå mer på djupet för att vara till större nytta. Ledare i en kris är något studenterna anser är viktigt, då många av dom inte vet hur eller vart de ska ta vägen om en kris skulle inträffa. Studien skulle kunna generaliseras och beröra fler respondenter förutom studenter. Individer i många olika sammanhang skulle kunna spegla sig i den situation som studenterna befinner sig i.The society stands for different kind of crisis and the citizens doesn’t seem to have enough preparation. Municipalities and authorities do play a crucial role for the resident’s safety when a crisis occur but at the same time the residents have their own responsibility regarding preparation for eventual crisis that may occur. MSB year 2018 got a mission from the government to distribute an information flyer to the public for to be able to raze their knowledge about crisis preparation. The information flyer would work as a tool for the public for to be able to take responsibility in a crisis. The purpose of this paper is to examine how students experience that their crisis preparations and which factors affect theirs preparation to a potential crisis. The data has been collected through interviews with students who received the information flyer and the data material has be analyzed with a quality content analysis. The results showed that the information flyer had a little impact on the students interest of purchasing preparedness kit but on the other hand the students had started to get thoughts of preparedness and crisis. Information is a very strong component for the student’s preparedness, but also the students do have a knowledge which regard own responsibility if a crisis should occur. The main responsibility though lays as the students tell on the authorities for the civilian’s safety but also the information which is sent out to them. Beside that the students consider that the civilians have also an own responsibility to make sure that they get the information sent to them from the authorities and the municipalities. As the students say there must be a cooperation between the authorities and the residents. Beside that the students consider that the information which is sent must needs to be obtained from different kind of sources of the media for to be able to get a correct and full information of a situation. Moreover, the student’s surroundings can affect their crisis preparedness due to family and friends. Handling medicine is something that is pointed out the information flyer didn’t include. Some medicines need to be chilled and thus also the it is considered that this question is important. The students mean that the information flyer needs to be more specific for to cover this and have a wider benefit. Leadership is also something that the students see as important due to many of them doesn’t know how or what to do if a crisis should occur. This study could be generalized and affect more respondents beside students. Individuals in many different situations could reflect themselves in the situation the students in the study are in.
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Meng, Yue. "The Daya Bay Reactor Neutrino Experiment." Diss., Virginia Tech, 2014. http://hdl.handle.net/10919/50534.
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The Daya Bay reactor neutrino experiment is a high sensitivity experiment designed to determine the last unknown neutrino mixing angle $theta_{13}$ by measuring disappearance of reactor antineutrinos emitted from six 2.9 $GW_{th}$ reactors at the Daya Bay Nuclear Power Station. There are eight identical Gd-loaded liquid scintillator detectors deployed in two near (flux-weighted baseline 512 $m$ and 561 $m$) and one far (1579 $m$) underground experimental halls to detect the inverse beta decay interaction. This dissertation describes the Daya Bay Experiment and individual contributions to this experiment.
Chapter 1 reviews the history of the neutrino and the neutrino oscillation phenomena. The reactor based neutrino experiments in different times are described in this chapter in detail. It presents the motivation of the Daya Bay Experiment. In Chapter 2, the neutrino detection method and the $theta_{13}$ relative measurement method are introduced. This chapter focuses on the design of the Daya Bay Experiment, including antineutrino detector, calibration system, muon veto system and muon tagging system. Chapter 3 shows the design, development, construction, and assembly of Muon Pool PMT calibration system, and presents an algorithm of calculating the muon pool PMT timing offset values. Chapter 4 focuses on the manufacture, installation and commissioning of RPC HV system. Chapter 5 presents the analyses of the radioactive isotopes induced by comic muons. The Daya Bay detector energy response model is also described in detail.
The relative rate analysis results exclude a zero value from $sin^22theta_{13}$ with a significance of 7.7 standard deviation using 139 days of data, 28909 (205308) antineutrino candidates which were recorded at the far hall (near halls) and shows $sin^22theta_{13} = 0.089pm0.011$ in a three-neutrino framework. A combined analysis of the $overline nu_e$ rates and energy spectra based on the detector energy response model improved measurement of the mixing angle $sin^22theta_{13} = 0.090^{+0.008}_{-0.009}$ by using 217 days of data, 41589 (203809 and 92912) antineutrino candidates were detected in the far hall (near halls). Also the first direct measurement of the $overline nu_e$ mass-squared difference $|Delta m^2_{ee}|= (2.59^{+0.19}_{-0.20})times10^{-3}$ $eV^2$. It is consistent with $|Delta m^2_{mumu}|$ measured by muon neutrino disappearance, supporting the three-flavor oscillation model.Ph. D.
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Moretti, Gabriele. "Studi sul guadagno dei fotomoltiplicatori per il luminometro LUCID dell'esperimento ATLAS a LHC." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amslaurea.unibo.it/7834/.
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Dall'inizio del 2013 il Large Hadron Collider (LHC) non produce dati (fase di shut down) per effettuare operazioni di consolidamento e manutenzione. Nella primavera del 2015 ritornerà in funzione con energia e luminosità maggiori.
La fase di shut down è sfruttata anche per migliorare le prestazioni dei vari rivelatori che operano in LHC, così che possano acquisire dati in modo efficiente alla riaccensione.
Per quanto riguarda il monitor di luminosità LUCID, che fa parte dell'esperimento ATLAS, sono stati sostituiti i rivelatori principali (i fotomoltiplicatori) e l'elettronica. Numerosi considerazioni rispetto alla durata dei nuovi sensori nell'ambiente di LHC tra il 2015 e il 2018, nonché sulla misura della luminosità durante il run II, hanno portato alla conclusione che i nuovi PMT dovranno operare ad un guadagno di math 10^5. E' stato dunque necessario, una volta identificati ed acquistati i nuovi sensori, qualificarne il funzionamento individuale e determinare la tensione di lavoro corrispondente al guadagno desiderato. La prima parte di tali misure, effettuate interamente a Bologna, riguarda la misura della corrente di buio e l'andamento della dipendenza del guadagno dei PMT dalla tensione applicata. La seconda parte riguarda invece lo studio di diversi metodi per le misure del guadagno assoluto, e la loro applicabilità durante la fase di funzionamento di LHC. Durante la presa dati, infatti, sarà essenziale essere in grado di monitorare continuamente il guadagno di ciascun sensore al fine di mantenerlo costante. Le misure di guadagno assoluto presentate in questa tesi sono state effettuate in parte a Bologna, sfruttando il metodo del singolo fotoelettrone, e in parte presso il CERN, utilizzando una sorgente radioattiva, il Bismuto 207.
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Classen, Lew [Verfasser], and Alexander [Gutachter] Kappes. "The mDOM – a multi-PMT digital optical module for the IceCube-Gen2 neutrino telescope / Lew Classen ; Gutachter: Alexander Kappes." Erlangen : Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 2017. http://d-nb.info/1138837490/34.
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Custódio, Gisele Santos. "Investigação e análise de parâmetros geotécnicos obtidos com ensaios de laboratório e ensaios in situ (DMT, PMT, SPT, PDM)." Universidade Federal de Viçosa, 2003. http://www.locus.ufv.br/handle/123456789/9667.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Este trabalho tem como objetivo analisar os parâmetros geotécnicos obtidos a partir de dados provenientes dos campos experimentais de Viçosa - M.G. (solo residual de gnaisse), e de Serra - Grande Vitória - E.S (solo residual proveniente de rocha sedimentar). Além disso, verifica a validade de algumas correlações encontradas na literatura e proposição de novas correlações baseadas nestes parâmetros. Foi feita a comparação entre a classificação unificada e a classificação quanto ao tipo de solo, obtidos pelo ensaio DMT, bem como a verificação da influência da sucção em alguns de seus parâmetros. São abordados os seguintes ensaios: (i) de campo: ensaio pressiométrico de pré-furo - PMT, ensaio dilatométrico - DMT, índice de resistência à penetração - SPT, ensaio de penetração dinâmica – PDM; (ii) de laboratório: ensaio edométrico, ensaio triaxial convencional, determinação da curva característica do solo, ensaios de caracterização (granulometria conjunta, massa específica dos sólidos, teor de umidade da amostra no estado natural, limite de liquidez, limite de xxviii plasticidade). Não foi realizado o ensaio PDM no campo experimental de Viçosa. No campo experimental de Serra, dentre os ensaios de laboratório, foram executados apenas os ensaios de caracterização. Como conseqüência deste estudo, infere-se a importância da consideração da sucção em parâmetros baseados na teoria clássica da mecânica dos solos, com o intuito de que não haja interpretações errôneas dos mesmos. Comparando-se as equações encontradas na literatura e as obtidas neste estudo, nota-se a existência de certa discrepância entre elas. Conclui-se então haver a necessidade da utilização de quaisquer correlações apenas para se prever a ordem de grandeza dos parâmetros envolvidos.
This work has the objective of analyzing the geotechnical parameters calculated from data of the experimental fields of Viçosa - M.G. (gnaisse residual soil), and from the Serra - Great Vitória - E.S (soil originating from residual sedimentary rock). Also it was verified the validity of some correlations found in the literature and proposition of new correlations based on these parameters. It was made the comparison between the unified classification and the classification in relation to the soil type, obtained by the DMT test, as well as the verification of the influence of the suction in some of these parameters. The field tests were: pressuremeter test - PMT, dilatometer test - DMT, Standard Penetration Test - SPT, Dynamic Manual Penetration Test- PDM and laboratory tests: Oedometer, conventional triaxial test, determination of soil characteristic curve, characterization test (united granulometric, specific mass of the solids, percentage of humidity of the sample in the natural state, liquidity limit, plasticity limit). The PDM test was not performed in the experimental field of xxx Viçosa. In the experimental field of the Serra, among the laboratory tests, the only one executed was the characterization tests. As a consequence of this study, it was noticed the importance of the consideration of the suction in parameters based on the classic theory of the mechanics of the soils, with the intention to prevent thaws erroneous interpretation of them. Comparing the equations found in the literature and the ones obtained in this study, it is noticed the existence of certain discrepancy among them. The need of correlations usage is concluded. In this case the in situ testing data should just be used to foresee the greatness order of the geotechnical parameters.
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Fruchtman, Jacob Alexander. "Analysis on the Feasibility of a prototype SOFOS Telescope Module for Optical SETI." Case Western Reserve University School of Graduate Studies / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=case1586779618246593.
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Herold, Björn [Verfasser], and Ulrich [Gutachter] Katz. "Simulation and Measurement of Optical Background in the Deep Sea Using a Multi-PMT Optical Module / Björn Herold ; Gutachter: Ulrich Katz." Erlangen : Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 2017. http://d-nb.info/1143232003/34.
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Kiel, Florian [Verfasser], Achim [Akademischer Betreuer] Stahl, and Alexander [Akademischer Betreuer] Schmidt. "Design and test of a power board for an intelligent PMT for the JUNO-detector / Florian Kiel ; Achim Stahl, Alexander Schmidt." Aachen : Universitätsbibliothek der RWTH Aachen, 2019. http://d-nb.info/1190360888/34.
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Moeller, Anthony Richard. "Forward physics in CMS : simulation of PMT hits in HF and Higgs mass reconstruction methods with a focus on forward jet tagging." Diss., University of Iowa, 2014. https://ir.uiowa.edu/etd/4700.
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Abnormally high energy events were seen in the Hadronic Forward (HF) calorimeter for pion and muon data during testbeam in 2004. Analysis of testbeam data suggested that such events were caused by particles traveling the entire length of HF and striking the photomultiplier (PMT) windows in the readout box behind HF. Charged particles traversing the window of the PMT emit cerenkov radiation, which creates abnormally high energy events in the data. To further study these events, a modification of the existing official CMS HF simulation was created that added the PMT windows to the simulation as sensitive detectors. In agreement with testbeam data, abnormally high energy events in the PMTs were seen in the simulation for muons and pions. The simulation was then extended to jets simulated with Pythia, and then for collision like events as well. PMT hits were seen in both of these cases. Energy sharing between PMTs for long and short fibers in HF as well as timing differences between normal HF events and PMT events were investigated as methods to tag such abnormal events. While both methods were somewhat successful, it was determined that they were not sufficient. The simulation was also modified to use thinner PMT windows. Reducing the thickness of the window reduced the number of PMT hits, and drastically reduced the energy of these hits, bringing most of them below standard jet energy thresholds. These results led to the replacement of the existing PMTs with new PMTs with a smaller, thinner window.
Higgs mass reconstruction methods were applied to Monte Carlo datasets for 115 and 130 GeV Higgs produced through vector boson fusion. In these datasets, the Higgs boson decayed to two tau particles, each of which decayed leptonically. The mass reconstruction methods successfully created a peak at the proper mass for both datasets. In addition to creating a Higgs, the vector boson fusion signal also has two forward jets. These jets are not found in the signal of the dominant background processes. By applying forward jet cuts to both the Higgs and the background events, it was possible to drastically improve the signal to background ratio for this channel. The Higgs boson was recently discovered at the LHC with a mass of approximately 125 GeV. As the methods discussed in this study are appropriate only for a low mass Higgs as the one discovered, they may prove useful in more precisely determining the mass of the Higgs.
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CAPELLI, SIMONE. "Search for lepton flavour violating τ^+ → µ^+ µ^− µ^+ decay at LHCb and study on MCP-PMT detector for future LHCb Upgrade." Doctoral thesis, Università degli Studi di Milano-Bicocca, 2023. https://hdl.handle.net/10281/403459.
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La parte principale della mia attività di ricerca svolta durante il dottorato consiste nella analisi di dati raccolti dalla collaborazione LHCb del CERN durante il Run2 (dal 2016 al 2018).
Lo scopo di questo lavoro consiste nella ricerca del decadimento del leptone τ in tre muoni (τ^+→µ^+µ^-µ^+)
Questo decadimento raro non ancora osservato violerebbe la conservazione del sapore leptonico, una quantità conservata accidentalmente nel Modello Standard (SM).
Nell'estensione minimale del Modello Standard che include neutrini massivi, il rateo di decadimento atteso B(τ^+→µ^+µ^-µ^+) è previsto essere dell'ordine O($10^{-55}$), ben al di sotto del livello di sensibilità degli attuali e prossimi futuri esperimenti.
Vi sono tuttavia teorie di Fisica oltre il Modello Standard (BSM) per le quali è previsto un aumento del rateo di decadimento di τ^+→µ^+µ^-µ^+ fino a valori O($10^{-10}$).
A oggi questo processo non è ancora stato osservato direttamente, ne da esperimenti a collisori leptonici (BaBar, Belle) ne a collisori adronici (LHCb), sono stati invece posti limiti superiori, che impongono limiti sempre più stringenti sulle teorie BSM.
Una eventuale osservazione di questo decadimento sarebbe un chiaro segnale di nuova Fisica.
L'analisi è stata svolta separatamente per ogni anno, utilizzando il decadimento Ds^+→φ(µ^+µ^-)π^+ come canale di riferimento rispetto a cui calcolare il B(τ^+→µ^+µ^-µ^+) in bin dei classificatori.
È stato utilizzato il metodo CLs per il calcolo del limite atteso, che risulta essere 1.8(2.2) x10^{-8} al 90%(95%) di C.L.
Gli studi di decadimenti molto rari come τ^+→µ^+µ^-µ^+ beneficeranno notevolmente dall'aumento di dati raccolti durante l'attuale Run3 e il prossimo Run4 dal rivelatore recentemente rinnovato. Durante la futura fase di alta luminosità che per l'esperimento LHCb comincerà con il Run5, esso sarà in grado di acquisire una maggiore quantità di dati grazie alla luminosità 10 volte superiore.
Per fare questo tuttavia è necessario progettare e sviluppare nuove componenti per rimpiazzare quelle attuali, che non saranno in grado di sostenere le nuove condizioni di funzionamento.
Per una parte del mio progetto di dottorato mi sono occupato della caratterizzazione della risposta temporale di un fotomoltiplicatore candidato per l'aggiornamento del Ring Imaging Cherenkov (RICH). Per il futuro upgrade è stato proposto di sfruttare l'informazione temporale delle tracce per ridurre il livello di pile-up. Fotorivelatori basati su MCP sono caratterizzati da una ottima risoluzione temporale, ma il loro impiego ad alti ratei di fotoni è complicato dalla saturazione a cui vanno incontro. Il rate atteso nella fase di alta luminosità è di circa 10MHz/mm$^2$.
L'Auratek-Square è uno strumento multianodo a microcanali (MCP-PMT) prodotto da Photek di 53x53 mm con 64x64 anodi raggruppati in 8x8 pixels. Ne è stata caratterizzata la risoluzione temporale in regime di singolo fotone, in funzione della tensione di alimentazione e del rateo di fotoni. Il rivelatore mostra eccellenti performance quando un singolo pixel viene illuminato, mostrando uno sparpagliamento del tempo di transito di circa 100ps FWHM quando esposto a un rateo di fotoni fino a ∼100kHz/mm$^2$.
Oltre tale soglia il fotomoltiplicatore satura e la risoluzione temporale peggiora velocemente. È possibile mitigare questo peggioramento riducendo sia la differenza di potenziale presente tra il fotocatodo e l’ingresso del MCP che la differenza di potenziale tra i piani del MCP, lavorando a basso guadagno. La capacità di timing è influenzata anche dal fenomeno di condivisione di carica (charge sharing) tra pixel adiacenti, che porta la risoluzione temporale a circa 170ps FWHM quando l’intera superficie del rivelatore è illuminata e che può risultare una delle sorgenti principali di crosstalk se non viene adeguatamente considerata.The physics analysis has been the primary focus of my research activity during the PhD. Within the CERN LHCb collaboration, I've performed an analysis of data collected during the LHC Run2 (2016, 2017 and 2018). The aim of this work is the search for the decay of the τ lepton into three muons (τ^+→µ^+µ^-µ^+), a decay that would violate the conservation of charged lepton flavour number (cLFV). The lepton flavour is an accidental symmetry of the Standard Model, and without the oscillations of neutrinos such decay would be prohibited. In the Minimal extended Standard Model the branching ratio B(τ^+→µ^+µ^-µ^+) is expected to be O($10^{-55}$), well below current and foreseen experimental sensitivity. Theories of physics beyond the Standard Model predict an enhancement of the τ^+→µ^+µ^-µ^+ decay within present experimental sensitivity O($10^{-10}$). This decay has not been observed to date, only upper limits have been established by B-factories (BaBar, Belle) or by hadron collider experiments (LHCb). The upper limit improvement implies strengthen of the constraints on exotic theories, while an observation of the decay would be a clear signal of New Physics. The analysis is performed separately for each year, and the data is divided into two subsamples depending on the number of muon candidates triggered by the LHCb muon system. Multivariate models are used to distinguish signal and background to enhance the signal sensitivity, and to define correction for data-simulation agreement. The Ds^+→φ(µ^+µ^-)π^+ channel is used as a reference channel to estimate the upper limit on the branching fraction. The expected upper limit is computed with the CLs method and results in 1.8(2.2)x10$^{-8}$ at 90%(95%) C.L.. The τ^+→µ^+µ^-µ^+ is an example of a very rare decay, and the analysis involving such decays will benefit from the increment of statistics that will be collected in the current Run3 and in the following Run4 period of data taking at the upgraded LHCb. The High-Luminosity phase of LHCb, starting with Run5 of the LHC, will provide a further boost to the amount of available data. The LHCb detector will need to undergo a second upgrade, to cope with the x10 increase of luminosity. Numerous studies and R&D projects are currently working on the development of technologies for the future detectors of LHCb. A part of my PhD project was devoted to work on a candidate photodetector for the upgraded Ring Imaging Cherenkov (RICH). I've characterized the timing performance of a multianode microchannel plate photomultiplier (MCP-PMT) in single photon regime. For the second upgrade it has been proposed to improve particle identification performance exploiting the use of precise timing information to cope with the increased pileup. MCP-based devices show excellent time resolution, but their use is critical due to saturation at rate above ~100kHz/mm$^2$. The expected rate that the future devices will have to stand is ~10MHz/mm$^2$. The Auratek-Square MCP-PMT produced by Photek is 53x53mm device with 64x64 anodes grouped into 8x8 pixels. The dependence of the time resolution from the bias voltage and the photon rate was assessed. When operating as single photon counter at low photon rate and with a single pixel illuminated it shows a transit time spread (jitter) of ~100ps FWHM, saturating at high rate, above ~100kHz/mm$^2$. Lowering the bias voltage between the photocathode and the MCP input or between the MCP slabs can reduce the worsening of the time resolution at high rate. The charge sharing between the neighbouring pixels can degrade the time resolution to ~170ps FWHM when the entire pixel area is illuminated, and could become a major crosstalk source if not accounted for.
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Hunter, William Coulis Jason. "Modeling Stochastic Processes in Gamma-Ray Imaging Detectors and Evaluation of a Multi-Anode PMT Scintillation Camera for Use with Maximum-Likelihood Estimation Methods." Diss., The University of Arizona, 2007. http://hdl.handle.net/10150/196121.
Full textAbstract:
Maximum-likelihood estimation or other probabilistic estimation methods are underused in many areas of applied gamma-ray imaging, particularly in biomedicine. In this work, we show how to use our understanding of stochastic processes in a scintillation camera and their effect on signal formation to better estimate gamma-ray interaction parameters such as interaction position or energy.To apply statistical estimation methods, we need an accurate description of the signal statistics as a function of the parameters to be estimated. First, we develop a probability model of the signals conditioned on the parameters to be estimated by carefully examining the signal generation process. Subsequently, the likelihood model is calibrated by measuring signal statistics for an ensemble of events as a function of the estimate parameters.In this work, we investigate the application of ML-estimation methods for three topics. First, we design, build, and evaluate a scintillation camera based on a multi-anode PMT readout for use with ML-estimation techniques. Next, we develop methods for calibrating the response statistics of a thick-detector gamma camera as a function of interaction depth. Finally, we demonstrate the use of ML estimation with a modified clinical Anger camera.
24
BOUVIER, Emmanuel. "Conception, synthèse et évaluations biologiques de prodrogues du paclitaxel et du docetaxel activées par voie enzymatique dans le cadre des stratégies de chimiothérapie anticancéreuse ADEPT et PMT." Phd thesis, Université René Descartes - Paris V, 2003. http://tel.archives-ouvertes.fr/tel-00009862.
Full textAbstract:
Le paclitaxel (Taxol®) et son analogue hémisynthétique le docetaxel (Taxotere®) appartiennent à une famille d'agents antitumoraux dont l'originalité réside dans leur structure tétracyclique inusuelle et complexe, et surtout dans leur mécanisme d'action. Ils ont en effet pour cible principale une protéine constitutive du fuseau mitotique, la tubuline.Bien que très utilisés en clinique (cancers du sein, de l'ovaire, du poumon), ils présentent un inconvénient majeur pour leur emploi : leur grande toxicité et leur mode d'administration induisent de graves effets secondaires. De plus, des phénomènes de résistance apparaissent également.
Une méthode efficace d'amélioration de ces composés est de les transformer en prodrogues moins cytotoxiques et plus hydrosolubles. L'intérêt prépondérant de cette transformation apparaît dans la possibilité de délivrer ces produits de manière mieux ciblée, plus spécifique des tumeurs. Elles pourront alors être utilisés dans le cadre du concept PMT (Prodrug Mono Therapy) ou dans une stratégie immunociblée de type ADEPT (Antibody Directed Enzyme Prodrug Therapy).
Dans cette optique, des prodrogues glucuronylées du paclitaxel et du docetaxel ont été conçues et synthétisées. L'espaceur employé est un espaceur double, reliant un carbamate de p-hydroxybenzyle à une chaîne diamine. Ces prodrogues ont été évaluées biologiquement (stabilité, cytotoxicité, hydrolyse enzymatique) pour valider cette approche. L'utilisation du nouvel espaceur a donné des résultats satisfaisants, en particulier pour les hydrolyses enzymatiques qui ont été améliorées par rapport à celles des prodrogues décrites précédemment. La conception et la synthèse de différents espaceurs applicables à la préparation d'autres prodrogues sont également présentées.
25
Bouvier, Emmanuel. "Conception, synthèse et évaluations biologiques de prodrogues du paclitaxel et du docetaxel activées par voie enzymatique dans le cadre des stratégies de chimiothérapie anticancéreuse ADEPT et PMT." Paris 5, 2003. http://www.theses.fr/2003PA05P623.
Full textAbstract:
Le paclitaxel (Taxol®) et le docetaxel (Taxotere®) forment une famille d'agents antitumoraux reconnue. Leur emploi induit de graves effets secondaires dûs à leur toxicité et à leur mode d'administration. Une amélioration possible est de transformer ces composés en prodrogues moins cytotoxiques et plus hydrosolubles. L'intérêt prépondérant de cette transformation apparaît dans la possibilité de délivrer ces composés de manière plus spécifique au niveau des tumeurs, par exemple dans le cadre des stratégies PMT ou ADEPT. Dans cette optique, des prodrogues glucuronylées du paclitaxel et du docetaxel contenant un espaceur double composé d'un carbamate de p-hydroxybenzyle relié à une chaîne diamine ont été synthétisées. Les résultats satisfaisants des évaluations biologiques (stabilité, cytotoxicité, hydrolyse enzymatique) ont validé cette approche. La conception et la synthèse de différents espaceurs applicables à la préparation d'autres prodrogues sont également présentéesPaclitaxel (Taxol®) and its semisynthetic analogue docetaxel (Taxotere®) belong to a family of efficient antitumor drugs and have been approved for the treatment of various cancers (ovarian, breast, lung). Their clinical use brings about severe side-effects due to their innate toxicity and formulation. Their transformation in less cytotoxic and more hydrophylic prodrugs is a way to improve their clinical use. Moreover a selective delivery to tumors in PMT or ADEPT strategies is then possible. To reach this goal, some glucuronylated paclitaxel and docetaxel prodrugs with a double spacer (p-hydroxybenzyl linked to a diamine tether by means of a carbamate) have been synthesized. This approach was shown efficient by the good results of the biological studies (stability, cytotoxicity, enzymatic hydrolysis). The conception and the synthesis of spacers useful for the preparation of other prodrugs are also presented
26
Mancuso, Andrea. "Neutron Veto of XENONnT: final construction design of the system and extensive study and calibration of the PMTs." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2020. http://amslaurea.unibo.it/19854/.
Full textAbstract:
Numerous and convincing are the experimental evidences that led to the believe that most of the Universe is constituted by the so-called Dark Matter (DM). Its research has attracted many experimental efforts to the point of being considered the greatest mystery of physics. The most promising candidates to DM are generically named as WIMPs, an acronym for Weakly Interacting Massive Particles.The detectors that have reached the most competitive sensitivity levels have in common the characteristics of being built with ultrapure materials and located underground, shielded from cosmic rays. The XENON project,located at the Laboratori Nazionali del Gran Sasso (LNGS). The XENON1T experiment employed a dual-phase Time Projection Chamber (TPC) with 2t of xenon active mass. The next step of the detector is XENONnT, and is currently in the final assembling stage. With a bigger TPC containing 6t of xenon active mass, the main goal is to improve the detection potential for WIMPs by increasing the sensitivity of one order of magnitude in five years of data taking. That result can be achieved only with a substantial background lowering attained with a reduction of the contaminants of the xenon as well as of the detector materials and finally, with the Neutron Veto system (nVeto); the latter is a detector which tags the radiogenic neutrons coming from the materials of the experiment. The nVeto will employ the gadolinium-loaded water technology to significantly enhance the neutron capture cross-section. It will be instrumented with 120 8'' Hamamatsu R5912 photomultipliers (PMT) featuring high quantum efficiency and low radioactivity. Most of the work done to design and realize the nVeto is the argument of this thesis. In addition, an extensive study of the nVeto PMT performance has been done in a dedicated experimental setup at the LNGS. The complete description of the setup,as well as the results of the nVeto PMT tests, is the other big topic of this thesis.
27
Leas, Loranie, and mikewood@deakin edu au. "Cardiovascular health behaviours and health needs among people with psychiatric disabilities." Deakin University. School of Psychology, 2004. http://tux.lib.deakin.edu.au./adt-VDU/public/adt-VDU20051208.095530.
Full textAbstract:
Recent research in Australia has found that people with a mental illness experience higher mortality rates from preventable illnesses, such as cardiovascular disease, respiratory disease and diabetes compared to the general population. Lifestyle and other behavioural factors contribute significantly to these illnesses. Lifestyle behaviours that affect these illnesses include lack of physical activity, consumption of a poor diet and cigarette smoking. Research on the influence of these factors has been mainly directed towards the mainstream population in Australia. Consequently, there remains limited understanding of health behaviours among individuals with psychiatric disabilities, their health needs, or factors influencing their participation in protective health behaviours. This thesis presents findings from two studies. Study 1 evaluated the utility of the main components of Rogers (1983) Protection Motivation Theory (PMT) to explain health behaviours among people with a mental illness. A clinical population of individuals with schizophrenia (N=83), Major Depressive Disorder (MDD) (N=70) and individuals without a mental illness (N=147) participated in the study. Respondents provided information on intentions and self-reported behaviour of engaging in physical activity, following a low-fat diet, and stopping smoking. Study 2 investigated the health care service needs of people with psychiatric disabilities (N=20). Results indicated that the prevalence of overweight, cigarette smoking and a sedentary lifestyle were significantly greater among people with a mental illness compared to that reported for individuals without a mental illness. Major predictors of the lack of intentions to adopt health behaviours among individuals with schizophrenia and MDD were high levels of fear of cardiovascular disease, lack of knowledge of correct dietary principles, lower self-efficacy, a limited social support network and a high level of psychiatric symptoms. In addition, findings demonstrated that psychiatric patients are disproportionately higher users of medical services, but they are under-users of preventive medical care services. These differences are primarily due to a lack of focus on preventive health, feelings of disempowerment and lower satisfaction of patient-doctor relationships. Implications of these results are discussed in terms of designing education and preventive programs for individuals with schizophrenia and MDD.
28
Hildreth, Sherry Boston. "Investigation of Protein-Protein Interactions among Nicotine Biosynthetic Enzymes and Characterization of a Nicotine Transporter." Diss., Virginia Tech, 2003. http://hdl.handle.net/10919/29698.
Full textAbstract:
Alkaloids are a class of plant secondary metabolites produced in about 20% of plant families. Domesticated tobacco, Nicotiana tabacum produces nicotine as the predominant alkaloid. The biosynthesis of nicotine occurs exclusively in the roots of tobacco, yet accumulates in the leaves of tobacco where it is acts as a defense compound to deter insect herbivory. The research detailed in this dissertation addresses two aspects of nicotine physiology in tobacco: 1) an investigation of hypothesized protein-protein interactions among nicotine biosynthetic enzymes and 2) the characterization of a novel nicotine transporter.
A hypothesized metabolic channel including the two nicotine biosynthetic enzymes putrescine N-methyltransferase (PMT), N-methylputrescine Oxidase (MPO) and the S-adenosylmethionine (SAM) recycling enzyme S-adenosylhomocysteine hydrolase (SAHH) has been proposed. To further explore this hypothesis, protein-protein interactions among nicotine biosynthetic enzymes PMT, MPO and SAHH were investigated using yeast two-hybrid assays and co-immunoprecipitation experiments. The yeast two-hybrid was conducted as both a directed screen to detect interactions between the hypothesized metabolic channel members and as a library screen to detect interactions between hypothesized metabolic channel members and proteins from a tobacco root cDNA library.
Co-immunoprecipitation experiments were conducted using proteins produced in an in vitro transcription/ translation system and using native proteins from a tobacco root extract. The outcome of these experiments provided no further evidence of a nicotine metabolic channel and a discussion of the methods and outcomes of the experiments conducted is presented.
The nicotine uptake permease, NUP1, was identified in tobacco roots and was shown to preferentially transport nicotine when expressed in Schizosaccharomyces pombe. This report presents the characterization of tobacco plants and hairy roots with diminished NUP1 transcripts created by using RNAi. The NUP1-RNAi hairy roots and plants showed a decreased level of nicotine and the hairy root cultures displayed an altered distribution of nicotine from the root to the culture medium. Additionally NUP1-GFP was used to determine that NUP1 localized to the plasma membrane of tobacco BY-2 protoplasts. Potential models for the role of NUP1 in nicotine physiology will be discussed.Ph. D.
29
Hildreth, Sherry B. "Investigation of Protein-Protein Interactions among Nicotine Biosynthetic Enzymes and Characterization of a Nicotine Transporter." Diss., Virginia Tech, 2009. http://hdl.handle.net/10919/29698.
Full textAbstract:
Alkaloids are a class of plant secondary metabolites produced in about 20% of plant families. Domesticated tobacco, Nicotiana tabacum produces nicotine as the predominant alkaloid. The biosynthesis of nicotine occurs exclusively in the roots of tobacco, yet accumulates in the leaves of tobacco where it is acts as a defense compound to deter insect herbivory. The research detailed in this dissertation addresses two aspects of nicotine physiology in tobacco: 1) an investigation of hypothesized protein-protein interactions among nicotine biosynthetic enzymes and 2) the characterization of a novel nicotine transporter.
A hypothesized metabolic channel including the two nicotine biosynthetic enzymes putrescine N-methyltransferase (PMT), N-methylputrescine Oxidase (MPO) and the S-adenosylmethionine (SAM) recycling enzyme S-adenosylhomocysteine hydrolase (SAHH) has been proposed. To further explore this hypothesis, protein-protein interactions among nicotine biosynthetic enzymes PMT, MPO and SAHH were investigated using yeast two-hybrid assays and co-immunoprecipitation experiments. The yeast two-hybrid was conducted as both a directed screen to detect interactions between the hypothesized metabolic channel members and as a library screen to detect interactions between hypothesized metabolic channel members and proteins from a tobacco root cDNA library.
Co-immunoprecipitation experiments were conducted using proteins produced in an in vitro transcription/ translation system and using native proteins from a tobacco root extract. The outcome of these experiments provided no further evidence of a nicotine metabolic channel and a discussion of the methods and outcomes of the experiments conducted is presented.
The nicotine uptake permease, NUP1, was identified in tobacco roots and was shown to preferentially transport nicotine when expressed in Schizosaccharomyces pombe. This report presents the characterization of tobacco plants and hairy roots with diminished NUP1 transcripts created by using RNAi. The NUP1-RNAi hairy roots and plants showed a decreased level of nicotine and the hairy root cultures displayed an altered distribution of nicotine from the root to the culture medium. Additionally NUP1-GFP was used to determine that NUP1 localized to the plasma membrane of tobacco BY-2 protoplasts. Potential models for the role of NUP1 in nicotine physiology will be discussed.Ph. D.
30
Reubelt, Jonas [Verfasser], Uli [Akademischer Betreuer] Katz, and Uli [Gutachter] Katz. "Hardware studies, in-situ prototype calibration and data analysis of the novel multi-PMT digital optical module for the KM3NeT neutrino telescope / Jonas Reubelt ; Gutachter: Uli Katz ; Betreuer: Uli Katz." Erlangen : Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 2019. http://d-nb.info/1178117014/34.
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31
Ramgolam, Kiran. "Effet des particules atmosphériques fines (PM2. 5, PM1) et ultrafines (PMO. 1) provenant de la région parisienne sur lépithélium respiratoire humain in vitro." Paris 7, 2007. http://www.theses.fr/2007PA077040.
Full textAbstract:
Les études épidémiologiques ont souligné l'impact des particules atmosphériques (PM) sur la santé avec des effets cardio-respiratoires. L'inhalation des PM provoque une inflammation de l'appareil respiratoire résultant d'une augmentation de la sécrétion de médiateurs proinflammatoires tels que le GM-CSF. L'objectif de cette thèse a été de caractériser in vitro la réponse pro-inflammatoire induite par les PM fines (PM2. 5 et PM1, de diamètre aérodynamique inférieur ou égal à 2,5 et 1 um) et ultrafines (PMO,1) dans des cellules épithéliales respiratoires humaines. La comparaison des différentes fractions granulométriques de l'aérosol parisien de fond (PMO. 03-0,1 ; PMO. 1-1 ; PM1-2. 5 et PM2. 5-10) a montré que la sécrétion du GM-CSF utilisée comme biomarqueur de la réponse pro-inflammatoire est toujours plus fortement induite par les particules fines PMO. 1-1 et ultrafines PMO,03-0,1 en corrélation avec leur contenu en carbone organique. L'étude des mécanismes de régulation de la réponse proinflammatoire par des PM2. 5 parisiennes a révélé (1) une augmentation de l'expression et de la sécrétion de l'amphiréguline (AR), un facteur de croissance ligand du récepteur à l'EGF (EGFR), via la transactivation de l'EGFR et de l'activation des voies des MAP Kinases, et (2) la participation de l'AR dans la régulation de la sécrétion du GM-CSF induite par l'exposition aux PM2. 5. Ce travail conforte l'hypothèse d'une plus forte réactivité biologique des particules fines et ultrafinesurbaines et révèle pour la première fois le rôle de l'EGFR et de ses ligands dans la réponse proinflammatoire induite par les PM dans les cellules épithélialesEpidemiological studies have highlighted the health impacts of ambient particulate matter (PM), and especially on cardio-respiratory diseases. Inhaled PM induces an inflammatory response in the respiratory tract that results from an increased release of inflammatory mediators such as the pro-inflammatory cytokine GM-CSF. The aim of this work was to characterize in vitro the pro-inflammatory response induced by fine (PM2. 5 and PM1 : particulate matter with an aerodynamic diameter les than 2. 5 and 1 um) and ultrafine (PM0. 1) particulate matter in human respiratory epithelial cells. The comparison of the size fractions of Paris aerosol (PMO. 03-0. 1, PMO. 1-1, PM1-2. 5 and PM2. 5-10) showed that fine PMO. 1-1 and ultrafine PMO. 03-0. 1 systematically induced the highest release of the pro-inflammatory biomarker GM-CSF. This pro-inflammatory effect was correlated to particle organic carbon content. The study of the mechanisms of the pro-inflammatory response induced by Paris PM2. 5 revealed that (1) the expression and release of the growth factor amphiregulin (AR) which is an EGF receptor (EGFR) ligand, were increased through EGFR and MAP Kinases activation and (2) AR participates in PM2. 5-induced GM-CSF release. These results strengthened the hypothesis of a higher reactivity of fine and ultrafine urban PM and highlighted for the first time the involvement of EGFR and its ligands in PM-induced pro-inflammatory response of respiratory epithelial cells
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Ortakaya, Ahmet Fatih. "Multivariate Time Series Modeling Of The Number Of Applicants And Beneficiary Households For Conditional Cash Transfer Program In Turkey." Master's thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/12610954/index.pdf.
Full textAbstract:
Conditional Cash Transfer (CCT) is a social assistance program which aims for investing in human capital by enabling families under risk of poverty to send their children to school and to benefit from health services regularly. CCT aims for decreasing poverty by means of cash transfers in the short run and aims for investing in children&rsquos human capital by providing basic preventative health care, regular school attendance and nutrition in the long run. Under the state of these aims, beginning from 1990s, more than 20 countries in the world started their own CCT program by the mediation or leadership of World Bank. CCT program in Turkey started so as to decrease the adverse effects of economic crisis in 2001 within the Social Risk Mitigation Project which was financially supported by the World Bank loan and constituted under the Social Assistance and Solidarity Foundation. CCT program in Turkey has been adopted by poor families in recent years, and demands and overall payments within the program have been increased significantly in a consideration of years. The need for examining and predicting the increase in these demands scientifically
and considering the fact that CCT is being applied over 20 countries, and such a study being never done before made this study necessary. In this thesis study, the change of CCT applications and number of beneficiary household over time were modeled using multivariate time series models according to geographical regions. Using the vector autoregressive models with exogenous variables (VARX), the forecasts were obtained for the number of CCT applications and beneficiary households in the future.
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Hebecker, Dustin. "Development of a single photon detector using wavelength-shifting and light-guiding technology." Doctoral thesis, Humboldt-Universität zu Berlin, 2021. http://dx.doi.org/10.18452/23231.
Full textAbstract:
Das IceCube Neutrino-Observatorium ist ein am geografischen Südpol im Eis installierter Neutrinodetektor. In IceCube werden Neutrinos mit Tscherenkow-Strahlung von Sekundärteilchen aus Neutrino Interaktionen detektiert. Für den Nachfolgedetektor IceCube-Gen2, werden neue und verbesserte Lichtdetektoren gesucht.
Die vorliegende Arbeit beschreibt die Entwicklung eines dieser Lichtdetektoren. Dieser basiert auf Wellenlängen schiebenden und Licht leitenden Technologien. Der Detektor mit dem Namen "Wavelength-shifting Optical Module" (WOM) verwendet eine transparente Röhre, mit wellenlängenschiebender Farbe, als passiver Photonendetektor. Das in der Wellenlänge verschobene Licht wird durch Totalreflexion, zu kleinen PMTs an beiden Enden geleitet. Die Auswahl dieses Designs reduziert die Kosten und verbessert das Signal-Rausch-Verhältnis wesentlich, möglicherweise können mit dieser Lösung extragalaktische Supernova in zukünftigen Detektoren beobachtet werden.
Als eine Kernkomponente wird die wellenlängenschiebende Röhre ausführlich untersucht. Verschiedene Messaufbauten und Auswertungsmethoden werden entwickelt, um diese im Anschluss zu untersuchen und zu bewerten. Iterative Verbesserungen der Materialien und des Farbauftrageverfahren als auch Messmethoden, resultieren in einer kombinierten Einfang-, Wellenlängenschiebe- und Transporteffizienz von 28,1 +/- 5,4 % der Röhre. Ein Model zur Beschreibung des Lichtverhaltens in der Röhre wird entwickelt um eine Diskrepanz zwischen Theorie und Messung zu untersuchen. Die Kombination zwischen Messung und Model, bestätigt die Aussagekraft des Models und zeigt, dass ein Großteil der Verluste beim Lichttransport zustande kommen.
Darüber hinaus werden die physikalischen Eigenschaften des WOM in die IceCube Simulationsumgebung eingebaut. Der Vergleich zu einem Konkurrenzmodul zeigt eine Überlegenheit des WOM um den Faktor 1,05 +/- 0,07. Es werden Vorschläge und Ausblicke für Verbesserungen der Leistungsfähigkeit des WOMs gegeben.The IceCube Neutrino Observatory is an in ice neutrino detector located at the geographic South Pole. In IceCube neutrinos are detected via Cherenkov light produced by secondary particles in neutrino interactions. For the upgraded detector IceCube-Gen2, new and improved light detectors are sought-after. This work describes the development of one of those light detectors based on a novel combination of wavelength-shifting and light-guiding technology. The detector named the Wavelength-shifting Optical Module (WOM) utilizes a large transparent tube, coated with wavelength-shifting paint as a passive photon detector. The wavelength-shifted light is guided via total internal reflection towards small active light detectors, at each end of the tube. This design reduces costs and improves the signal to noise ratio significantly, thereby potentially enabling extragalactic supernova detections in future detectors. As a core component, the wavelength-shifting tube is extensively investigated. Different measurement setups and evaluation techniques are developed and investigated. Iterative improvement of materials and coating techniques as well as measurement methods currently result in a combined photon capture, shift and transport efficiency of 28.1 +/- 5.4 % for the tube. Those results contrast the theoretical maximum of 74.5 %. A model is developed to describe the light propagation and loss processes in the tube and to understand the discrepancies between theory and measurement. The combination of the measurements with the model, validate the descriptive qualities of the model and show that most of the light is lost during the light propagation in the tube. Additionally, the physical properties of the WOM are included in the IceCube simulation framework. A comparison to a competing module showed that the WOM outperforms by a factor of 1.05 +/- 0.07 in photon detection numbers. Where applicable, suggestions and outlooks are given to enhance the performance of the WOM.
34
Kuwaiti, M. E. "The role of performance measurement systems in the design and implementation of business process re-engineering." Thesis, Cranfield University, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.340872.
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Lay, James. "La bourse et les mécanismes de financement des PMI-PME." Poitiers, 1986. http://www.theses.fr/1986POIT3009.
Full textAbstract:
Il faut attendre 1983 avec la creation du second marche pour voir la communaute financiere et boursiere s'interesser aux petites et moyennes entreprises. Cette nouvelle structure d'accueil permanente rencontre rapidement un succes et semble repondre aux differentes motivations des chefs d'entreprise. Pour que ce phenomene se generalise, les intermediaires financiers (banques, agents de change, bourses regionales, cabinets specialises) doivent faire l'effort de prospection, d'information, de conseils. En effet s'introduire en bourse n'est pas une decision a prendre a la legere. Chaque entreprise represente un cas marginal qui merite d'etre analyse. La cle de la reussite d'une bonne introduction passe par l'elaboration d'un complet dossier d'introduction qui aboutit a retenir un cours ni trop eleve, ni trop bas. Cent soixante entreprises sont ainsi venues sur ce second marche (sans compter le hors cote d'acclimatation)permettant au marche financier francais de se regenerer avec des societes plus jeunesIt was only in 1983 that the financial community took interest in middle sized firms with the creation of the second market. This new ceaseless structure replies to the wishes of the managers of these firms. For the generalization of this phenomena, all the financial middlemen (banks, stockbrokers, local stock-exchange. . . . ) have to put the emphasis on : prospection, informations, advices. In fact, getting in stock-exchange musn't be an unthinkly decision. Each firm muste be regarded as one particular case whiche requier a deep analysis. The key to success states on the elaboration of a complete get in dossier. This will end at the establishement of the real market price of the share. Yet, one hundred and sixtie companies have been welcomed on the second market ("hors cote d'acclimation" excluded) this situation allowed the financial market to regenerate itself with new younger companies
36
Moita, Michel. "Management par la logistique globale d'un réseau de PME-PMI." Toulon, 2003. http://www.theses.fr/2003TOUL2003.
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Les prémisses de notre recherche se résument en une double problématique professionnelle: la France est sous-équipée en caisses amovibles, comment procéder pour réduire ce handicap? ; les progiciels de S. C. M. (Supply Chain Management) sont hors de portée pour les PME-PMI, comment les organiser pour y accéder? Le design de notre papier est conçu en cinq parties: la présentation de la weltanschauung teilhardienne ; l'axiomatique du système/objet; la réfutation de la pensée conforme; la modélisation de l'objet et, la validation par le satisfacing. Le corpus théorique de notre thèse s'appuie sur les théories du constructivisme, du Système Général de Le Moigne et " administrative " de Simon. Le terrain choisi est celui des Chambres consulaires. La construction ex nihilo d'un réseau s'avère utopique dans le contexte de notre thèse; ce qui nous a conduit à proposer la métamorphose systémique de la Chambre de métiers de la Haute-SavoieThe premises of our research can be described through a two-fold professional challenge. The France is under-equipped in terms of removable containers. What should be done to reduce this handicap? The S. C. M. (Supply Chain Management or global logistics) software are out of reach for small and midsize companies. How can they be organized in order to make them accessible? Our paper is designed in five parts: the introduction presents the teilhardian weltanschauung, the axiomatic of our research, the refutations of the "true thought", the modelling leads of the object and, the validation by the satisficing. The theoretical corpus of out thesis is founded on three theories : the constructivism, the General System, Simon "administrative " theory. We chose the field of the consular Chambers. We realized that the construction from scrap of a network is not realistic in the context of our thesis which led us to propose the systemic metaphor of the "Chambre de métiers" of Haute-Savoie
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Moussaoui, Hassan. "Contribution à la connaissance des objectifs financiers des PME-PMI." Bordeaux 1, 1985. http://www.theses.fr/1985BOR1D312.
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Lay, James. "La Bourse et les mécanismes de financement des PME-PMI." Lille 3 : ANRT, 1987. http://catalogue.bnf.fr/ark:/12148/cb375990069.
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Kittler, Thomas [Verfasser], Gisela [Akademischer Betreuer] Anton, Gisela [Gutachter] Anton, and Alexander [Gutachter] Kappes. "Simulation and Reconstruction of Muon Tracks with the "multi-PMT Digital Optical Module" in Comparison to the "PINGU Digital Optical Module" for the IceCube-Gen2 High-Energy Array / Thomas Kittler ; Gutachter: Gisela Anton, Alexander Kappes ; Betreuer: Gisela Anton." Erlangen : Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 2020. http://d-nb.info/1215908024/34.
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NZOLOUFOUA, JUSTIN. "Essai d'analyse du comportement des entrepreneurs PME-PMI face à l'investissement." Caen, 1987. http://www.theses.fr/1987CAEN0501.
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Economie contemporaine se caractérise par un mouvement de croissance continue qui contraint très vite l'entreprise, à s'adapter au marché et à lutter contre la concurrence. Pour croître, il faut investir en garantissant ou en renforçant ainsi la position acquise. La façon de se comporter face à ce choix fondamental qui est l'investissement ; diffère selon que l'on se trouve dans une grande entreprise ou une petite et moyenne entreprise. Pour cette dernière, l'hétérogénéité de la population qui la compose constitue le fruit d'une grande disparité des attitudes et aussi des valeurs de référence des décideurs. Les valeurs et les attitudes sont susceptibles d'expliquer le comportement des individus, en tant qu'informations cognitives et éléments de la personnalité, elles prédisposent l'homme à un certain comportement. Face aux décisions concernant les problèmes d'investissements le comportement de l'entrepreneur P. M. E P. M. I. Porte généralement sur des considérations subjectives. Il s'ensuit que les autres membres de l'entreprise jouent un rôle toujours moins important dans l'élaboration de telles décisions qui sont pour une part toujours plus grande, réserves. Le développement futur de son entreprise peut se confondre avec ses propres valeurs ou ses perspectives personnellesModern economy characterizes itself by a continuous increase that soon constrains the company to adapt itself to the market and fight against competition. Fortis increase a company must invest by getting benefits or reinforcing the acquired position. Facing with this fundamental choice, which is investment, the way of behaviouring is different according as you own to a big or small and middle - sized company. For this latter, the heterogeneity in population which composes it does constitute the result of a great disparity in attitudes and also in settlers reference values, values and attitudes are susceptible to justify individual behavior. As far as cognitive informations and personality components, they predispose the man in a certain behavior. Face to decisions regarding investment problems, the P. M. E. P. M. I. Contractor's behavior is generally concerning with subjective concerning with subjective considerations, hence it follows that the company other members are always playing a less important role in the elaboration of such decisions which, always in a great measure are reserved to the company dealer. The figuration this latter make himself of his company future increase may be confounded with his own values or personal perspectives
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Larsen, Gerrit T. "Piezoresistive Models for Polysilicon with Bending or Torsional Loads." Diss., CLICK HERE for online access, 2009. http://contentdm.lib.byu.edu/ETD/image/etd3165.pdf.
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Retourna, Christophe. "Analyse de cas concrets d'innovations dans les PME-PMI : problématiques et discussions." Aix-Marseille 3, 1995. http://www.theses.fr/1994AIX30095.
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Si les notions d'intelligence économique et de veille technologique prennent de plus en plus d'importance comme facteurs de compétitivité des entreprises, l'innovation est un autre de ces facteurs. Les modalités de l'innovation sont ici abordées d'après un certain nombre de rencontres que nous avons menées auprès des dirigeants de PMI et de PME d'une zone économique en difficulté. Nous avons dégagé des variables d'innovations de l'analyse des interviews semi-directives recueillies auprès d'un échantillon d'entreprise. Des modèles descriptifs d'intéractions de ces variables sont proposés en vue d'une meilleure compréhension des processus d'innovation. D'autre part nous décrivons une méthodologie d'analyse de discours oral des dirigeants d'entreprises à l'aide d'outils bibliométriques initialement conçus pour l'analyse de grandes quantités de données de type bibliographique. Les deux méthodes, analyse thématique et statistique, donnent des résultats complémentaires. Enfin, l'accent est mis sur la relative imprécision des informations disponibles sur les activités et technologies caractéristiques d'un tissu économique donné en vue d'une opération de transfert de technologie ou de coopération recherche-industrie. Un système d'information est proposé pour établir une corrélation à priori entre les activités d'entreprises et les thématiques de la recherche publique
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Coulibaly, Mamadou. "Les problèmes des PME/PMI de Côte d'ivoire et l'information économique et sociale." Bordeaux 3, 1989. http://www.theses.fr/1989BOR30014.
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L'information economique et sociale prend de l'essor dans les societes modernes ; appliquee a une entreprise, elle devient un flux indispensable pour la regulation du systeme de l'entreprise. Si les grandes entreprises ont les moyens de traiter cette information, il n'en est pas de meme pour les petites et les moyennes. Nous avons essaye de replacer cette information dans le contexte de la petite et moyenne entreprise ivoirienne. Ainsi, dans une premiere partie, nous avons montre que malgre la crise qui sevit dans ce pays depuis plus d'une decennie, les pouvoirs publics tentent d'amorcer la promotion des petites et moyennes entreprises par la creation d'organismes d'assistance et de promotion ; mais les resultats sont encore eloignes des esperances. Dans une seconde partie, apres presentation des sources de diffusion et de production des informations economiques et sociales, suivie de l'analyse de contenu de fraternite matin, strategies economiques et marches tropicaux et mediterraneens, il s'est avere que malgre la diversite des sources, celles-ci n'etaient pas orientees en priorite vers les petites et moyennes entreprises. Mais il ne fallait pas se limiter a cette analyse ; ainsi, les resultats de nos enquetes nous ont permis de voir que de nombreuses entreprises n'organisent pas leurs structures et leurs communications ; il enEconomic and social information is becoming more and more important in modern societies. Applied to an enterprise it constitutes an essential flow in the enterprise system. But if big firms have ways and means to treat this information, it is not the same for the smaller and the medium. So our duty consisted to replace this information in the context of ivoirian small and medium-sized enterprises. Thus, in a first part consecrated to ivoirian economy, we proved in spide of the crisis which is persisting for ten years, the authorities are trying to initiate promotion for these enterprises. For this purpose, a lot of assistance and promotion organisms have been created, but their results are too far from the expectations. In a second part, after having presented the different sources of production and diffusion, we have analysed the contents of fraternite matin, strategies economiques and marches tropicaux et mediterraneens, and we seen in spide of the diversity of sources they was not oriented in priority towards small and medium-sized enterprises. But is was not necessary to stop to this first analysis ; so the results of our investigations proved that many enterpri
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Voyant, Olivier. "Contribution a l'elaboration d'un systeme de veille strategique intégré pour les PME-PMI." Lyon 2, 1997. http://www.theses.fr/1997LYO22019.
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Dans les revues specialisees tout comme dans les revues economiques, on parle de plus en plus de veille technologique, de veille concurrentielle, de veille strategique. Cependant, peu nombreuses sont les pme-pmi qui maitrisent les notions liees a ces concepts : on confond le systeme d'information avec la veille, la veille technologique et la veille strategique, ou encore, on assimile la veille strategique et l'analyse strategique. De plus, lorsque l'on interroge les entreprises sur leur systeme de veille strategique, on constate qu'elles mettent en place des actions sans pour autant les identifier : elles semblent utiliser des pratiques de veille strategique, leurs responsables en sont persuades, mais ils eprouvent les plus grandes difficultes lorsqu'il s'agit d'en faire le recensement. Les actions conduites peuvent, par voie de consequence, souffrir de redondance, d'inefficacite et de manque de synergie, ce qui affecte la preparation de l'entreprise aux enjeux actuels et futurs. Cettethese a pour objectif d'esquisser quelques reponses a ces questions. Dans un premier temps, l'elaboration theorique d'un systeme de veille strategique est proposee afin d'apporter un eclairage sur chacun des concepts etudies. Ensuite, une re-visite du systeme par l'experimentation est abordee. Elle consiste, d'une part, a proposer une methodologie specifique de diagnostic des pratiques de veille strategique des pme-pmi, d'autre part, a mettre en place le developpement du systeme identifie a l'aide d'une methodologie de projet. Enfin, suite a l'experimentation, le systeme elabore est enrichi par la mise en lumiere du role des outils de management et des acteurs, ce qui permet de renforcer l'aspect dynamique du systeme proposeSpecialized journals as well as economic magazines are more and more about technological monitoring, competitive monitoring and strategic monitoring. However very few smes do master the notions related to these concepts : one always mixes up the information system with the monitoring, or the technological monitoring with the strategic monitoring, or else the strategic monitoring with the strategic analysis. Furthermore when companies are asked about their strategic monitoring system, statement can be made that they set up actions without identifying them : they seem to use strategic monitoring practices, and so believes the management, but they experience great difficulty making an inventory of such pratices. Consequently these actions may be redundant or ineffective or may lack of synergy, which treatens the company's preparing for present and future stakes. The present thesis aims at outlining a few answers to these questions. First of all, the theoretical elaboration of a strategic monitoring system is put forward in order to clarify the concepts studied. Secondly the system is "re-visited" thanks to experimentation. It consists on the one hand in proposing a specific diagnosis methodology of smes' strategic monitoring practices, and on the other hand in developing the identified system through a planning methodology. Lastly, after experimentation, the elaborated system is enriched by outlining the role of management tools and actors, which allows to strengthen the dynamic aspect of the proposed system
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Lanoux, Blandine. "L'adoption par les PME-PMI des systèmes de gestion basés sur les processus." Université Louis Pasteur (Strasbourg) (1971-2008), 2001. http://www.theses.fr/2001STR1EC12.
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La problématique traitée dans cette thèse est la suivante : Comment et avec quel succès les systèmes de gestion basés sur les processus peuvent-ils être adoptés par les PME / PMI ? Les systèmes étudiés sont d'une part les modèles de gestion par la Qualité de type ISO 9000 ou TQM, et d'autre part des systèmes plus ciblés de type JAT (Juste-à-Temps) ou ABM (Management Basé sur les Activités). Le socle empirique sur lequel repose cette recherche est une étude monographique réalisée au sein de deux PMI alsaciennes dans le cadre d'une convention CIFRE. L'incompatibilité apparente entre instruments de gestion et organisation flexible de la petite firme amène à s'interroger sur le contenu des systèmes de gestion par processus et sur leur caractère universel. S'il est effectivement possible d'opérer une adaptation des outils aux spécificités des PME, reste à comprendre comment se déroule l'implantation elle-même. C'est le dirigeant de PME qui décide du lancement du projet d'implantation et qui guide les membres de l'organisation. Pour cette raison, il est important de comprendre qui il est - entrepreneur ou manager - et comment il interagit avec son environnement. Par l'observation du réel, d'autres facteurs clés peuvent encore être dégagés pour expliquer la réussite ou l'échec des tentatives d'implantation de systèmes de gestion par processus dans les PME, notamment le rôle des relayeurs internes ou externes du projet. Ces individus " hybrides " contribuent à maintenir l'équilibre entre apprentissage d'exploitation et apprentissage d'exploration dans l'organisationThe thesis focuses on the following issue : "How and with what level of success can management systems based on processes be implemented in SMEs ?" The studied systems are quality models such as ISO 9000 standards or TQM (Total Quality Management). But more targeted systems are also examined such as JIT (Just-in-time) or ABM (Activity based Management). The research is based on an empirical study carried out within two Alsatian SMEs during a four year period, as part of a contract between these companies and the BETA laboratory. First, the apparent incompatibility between management tools and the flexible nature of small organizations leads to analyse the content of the process management tools and to question about their universal characteristic. Then, if the instruments can actually be adapted to SMEs specificities, what do we know about the implementation unfolding ? The decision to launch the implementation project is made by the head of the firms, who follows it through. So, it is important to understand who is the entrepreneur or the manager and how he interacts with his environment. By observing real behaviours, key-factors can be recognized in order to explain the success or the failure of management systems implementation in SMEs, in particular the roles of internal and external "relay runners" of the project
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Akhimie, Regina Nicole. "Investigation of Rh2(II,II) complexes for applications in photochemotherapy and mismatch detection." The Ohio State University, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=osu1511892689942643.
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Gondran, Natacha. "Système de diffusion d'information pour encourager les PME-PMI à améliorer leurs performances environnementales." Phd thesis, Ecole Nationale Supérieure des Mines de Saint-Etienne, 2001. http://tel.archives-ouvertes.fr/tel-00804929.
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Les petites et moyennes entreprises prédominent dans le tissu industriel français. Manquant de moyens (humains et financiers), la plupart d'entre elles ne recherchent pas spontanément l'information environnementale et considèrent l'environnement comme une contrainte et non comme un atout. Elles sont donc réticentes à investir pour l'environnement et s'enferment dans un "cercle de passivité". Leur impact environnemental global ne peut cependant être négligé et préoccupe de plus en plus leurs parties intéressées. Notre objectif est d'analyser leur système d'information environnementale pour identifier les améliorations qui peuvent y être apportées afin de les encourager à réduire leurs impacts environnementaux négatifs. Nos hypothèses sont que le postulat de rationalité parfaite ne peut s'appliquer au cas de l'intégration de l'environnement par les PME / PMI et que l'accès à l'information environnementale est une condition nécessaire à sa maîtrise des impacts environnementaux. Pour les valider et identifier les flux et canaux d'information nécessaires à la diminution des impacts environnementaux, nous proposons une démarche évaluant le comportement environnemental de la PME à partir de son niveau d'accès à l'information environnementale. Cette méthode a été utilisée pour mener une enquête auprès de 47 PME / PMI. Nous avons également analysé plus de 300 renseignements fournis à des entreprises par les services "SVP environnement" de deux associations d'industriels. Les données recueillies ont été traitées par analyses factorielles, tri à plat et tableaux croisés. Notre enquête montre que le canal d'information privilégié des PME / PMI est le contact direct avec différentes organisations et que plus une entreprise est ouverte sur ses partenaires, mieux elle intègre l'environnement. Chaque PME a un "profil de partenaires" différent selon son territoire d'implantation, son niveau d'indépendance, son statut ICPE et sa situation par rapport à la certification qualité. La majorité des entreprises interrogées ne respectent pas la totalité des exigences de la réglementation ICPE. Six caractéristiques influencent significativement le niveau d'intégration de l'environnement de l'entreprise : son statut ICPE, la présence d'un responsable environnement, le type de motivation de son dirigeant et sa situation vis-à-vis de la certification qualité. Nous avons également validé une grille évaluant le comportement environnemental de la PME à partir de 15 critères sur une échelle à trois niveaux (écodéfensif, écoconformiste et écosensible). L'analyse des questions posées aux centres de ressources nous a amenés à classifier l'information selon 4 axes : son type (sur l'environnement, sur les moyens d'intégrer l'environnement, sur les éco-acteurs et sur les événements et références), son thème, ses niveaux décisionnel et géographique. Une représentation de l'utilisation de l'information environnementale par la PME / PMI est proposée sur la base du modèle du méta-système de J. VAN GIGCH. Elle permet d'identifier les carences des PME / PMI en information environnementale. Pour encourager les PME / PMI à améliorer leur gestion environnementale, il semble nécessaire de faciliter les partenariats entre acteurs publics et privés afin de faire transiter l'information environnementale par des acteurs locaux pouvant établir un contact direct avec les industriels. Aussi, nous proposons un guide méthodologique pour des projets visant à diffuser de l'information aux PME pour les encourager et aider à mieux maîtriser leurs impacts environnementaux.
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Padula, Antonio Domingos. "Une méthodologie de diagnostic organisationnel global pour le conseil de direction en PME-PMI." Grenoble 2, 1991. http://www.theses.fr/1991GRE21008.
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Les pme-pmi sont parfois confrontees a des problemes de management dont la solution echappe a leur possibilites materielles et humaines. L'une des attentes du dirigeant a l'egard deson conseil est qu'il l'aide a resoudre ces problemes. De par sa place privilegiee, l'expert-comptable est un conseil tout naturel des pme-pmi. Mais les cabinets ne sont pas actuellement prepares pour satisfaire ces attentes des dirigeants. Ils ressentent le besoin de methodologies et d'outils pour faciliter leur propre evolution professionnelle vers un conseil plus global et plus managerial. En partant de ce constat, nous avons formule une problematique concernant les deux points suivants : l'activite de conseil en gestion aux pme-pmi et le processus de developpement de ces organisations. A cette problematique, nous avons fourni une reponse au terme d'une recherche-action pour la conceptualisation, la formalisation et la validation d'une methodologie de diagnostic organisationnel global. En systematisant et enrichissant les differentes connaissances, qui etaient parcellisees et dispersees, nous en avons comble certaines lacunes dans le domaine du conseil en pme-pmi et du processus de transition organisationnelleSmall and mid-sized firms are often confronted with problems of management beyond their human and material resources. One of the major expectations of executives is help from consultants to solve such problems. Accounting specialists are naturally called on by such firms. However, nowadays they aren't ready to satisfy executives's expectations. They feel the need for specific approachs and tools to ease their professional evolution towards more general managerial solutions for such firms. Considering this situation, we've formulated a research problem that takes into account the following points : the specificity of consulting activity to small and mid-sized firms and the development process of such organizations. Then we proposed a solution resulting from action research into the issue so as to conceptualize, formalize and validate a method of overall business diagnosis. By enriching first then making systematic hither-to-fore dispersed and fragmentary knowledge, we have filled in the gaps on knowledge as far as consulting activities towards small and mid-sized firms, as well as contributing to e better understanding of their transitional problems
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Saade, Jad. "L'outil internet dans les PMI-PME et les stratégies à adopter : le cas libanais." Chambéry, 2009. http://www.theses.fr/2009CHAML012.
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L'environnement mondial s'accompagne de stratégies et de méthodes de développement récentes qui font que les petites et moyennes entreprises (PME) affrontent de nouveaux défis et se trouvent obligées de les relever pour connaître une pérennité. Nous avons jugé intéressant de nous concentrer sur les PME implantées au Liban, pays où le risque de guerre est toujours incessant depuis 1975 à ce jour, et situé dans une région déchirée par des conflits de tout genre depuis plusieurs décennies. De ce fait, le pays ploie sous le poids d'une crise économique perpétuée, ce qui influe ces PME d'une part par une baisse de la demande, due au recul du pouvoir d'achat des consommateurs et, d'autre part, de la baisse de leur compétitivité. Une expression primordiale de la modernité se manifeste dans le phénomène internet, son application sur les PME et PMI (petites et moyennes industries) s'avère inévitable, d'où une nécessité de l'étude de son impact et des difficultés occasionnées par cette application, ainsi que les clés de réussite des PME libanaises pour arriver à la fin à proposer des solutions adaptées en termes de stratégie. Plusieurs thèmes ont été étudiés au cours de la présente thèse, à savoir, la question si la nouvelle économie mettait en danger les PME libanaises en plus du développement massif des grandes entreprises multinationales, la nécessité de l'adoption des techniques de l'informatique dans le cadre des activités des PME, surtout dans l'application du commerce en ligne, et l'ouverture des activités des PME pour dépasser les frontières libanaises. En réponse à ces points, un cadre théorique a été exposé pour identifier les spécificités des PME libanaises face au mouvement de mondialisation, une présentation d'une PME que nous avons créée a été exposée, faisant l'objet d'une expérimentation terrain pour l'élargissement des activités des PME pour englober la planète. Cette expérience a permis de noter plusieurs observations pour une représentation différente de la globalisation comme processus et par la suite en test des tactiques adoptées et l'estimation de notre stratégie en définissant et justifiant la méthode d'internationalisation choisie, les observations à collecter et la méthode d'analyse utilisée. L'ultime point relevé dans notre thèse a été la création d'un baromètre dans le but de mesurer la performance des PME au Liban, démarche incitée par plusieurs facteurs internationaux, en l'occurence la crise économique internationale déclenchée en 2008 aux Etats-UnisStrategies and modern development methods are an integral part of the world-wide environment. Small and medium enterprises (SMEs) face new challenges and find themselves in a position to confront them in order to survive. We therefore found it significant to focus on the SMEs in Lebanon , a country living under permanent risk of war since 1975, located in an area impacted by conflicts of all kinds for several decades. As a result, the country bows under the weight of a lasting economical crisis, which on hand influences these SMEs by a decrease in demand, the consequence of a fall in consumer's purchasing power, and on the other hand, the decline of competitiveness. An essential modernity expression is illustrated in the internet phenomenon. Its application on SMEs and SMI (small and medium industries) is unavoidable, leading to the need of a study of the impact and difficulties causes by this application, as well as the Lebanese SMEs keys to success, and lastly to propose solutions that can be adapted in terms of strategy. Several topics have been studied through our thesis, including whether the new international economy, and moreover the massive development of the giant multinational businesses, jeopardize the Lebanese SMEs, as well as the data processing techniques adoption requirement in the SMEs activities structure, especially in the online business application , and the SMEs capacity to exceed the Lebanese frontier. In response to these points, we produced a theoretical framework to identify the specificities of Lebanese SMEs facing the globalization movement. We created an SME as our case study, the objective being to experiment with a geographical zone in order to expand the SMEs activities to embrace the planet. This experience permitted the noting of several observations for a different perspective on the globalization process, and subsequently an adopted tactics test and the evaluation of our strategy by defining and justifying the selected method, the observations to be collected and the analysis method used. The ultimate point raised in our thesis was the creation of a barometer with an aim of measuring the performance of SMEs in Lebanon, a step encouraged by several international factors, particularly the 2008 international economic crisis which originated in United States
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Rouhani, Hassan. "Climate change impact on probable maximum precipitation and probable maximum flood in Québec." Thèse, Université de Sherbrooke, 2016. http://hdl.handle.net/11143/8824.
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Abstract : As atmospheric temperatures at the Earth’s surface increase due to global warming, the capacity of lower atmospheric levels to hold water vapor rises and thus, precipitations and floods will be influenced. In turn, extreme precipitation and flood events are subject to potential modifications under climate change, namely, Probable Maximum Precipitation (PMP) and Probable Maximum Flood (PMF). This research aims at analyzing climate change influences on PMP and PMF in three watersheds with different climatic conditions across the province of Québec, Canada. The watersheds are located in the south, center and north of the province. They have been selected in a manner which reflects climate diversity across Québec.
In order to study climate change conditions, the data output of the Canadian Regional Climate Model (CRCM) was used. This database covers a time horizon from 1961 up to 2100 and includes daily precipitation, temperature, specific humidity and Convective Available Potential Energy (CAPE). These data were used to estimate PMP. The World Meteorological Organization (WMO) method was adapted to estimate PMP values under climate change conditions. The 100-year return period precipitable water (W100) was selected as an upper limit of precipitable water in establishing maximization ratio. The time series for estimating W100 was established from annual maximum precipitable water values that have similar atmospheric variables of the event to be maximized. The atmospheric variables used in this research were atmospheric temperature at the Earth’s surface and CAPE. This method does not require setting any upper bound limit to the maximization ratio and is therefore more amenable to calculate the PMP in a climate change context.
The PMP was used to run a distributed hydrological model to estimate PMF. PMP and PMF values were estimated in three 45-year time horizons: recent past (centered on 1985), near future (2030) and far future (2070). In regions where snowmelt plays a key role in the annual hydrological cycle, winter-spring flooding could be the major discharge. Consequently, PMP and PMF were separately analyzed in two seasons: summer-fall (snow-free) and winter-spring (snow accumulation and melt). The largest value obtained was identified as the all-season PMP/PMF. Summer-fall PMF was estimated by inserting the PMP in each day of the simulated time horizon. Therefore, all soil moisture conditions prior to PMP occurrence were included. Accordingly, a distribution of PMF values based on different initial conditions (soil wetness levels) was obtained. Winter-spring PMF was estimated by inserting the PMP value at the end of a warm melting period and for an extreme snow accumulation.
Our results show that the PMF of three watersheds would occur in the winter-spring season in current and future climate projections. Furthermore, all-season PMP and PMF in southern Québec would decrease, but trends in central and northern of Québec would be reversed and the PMP and PMF would increase in projected climate conditions. In the center and north of Québec, the PMF would increase by 25 and 23% respectively, at the end of the 21st century. For the same period, PMF would have a reduction of 25% in the south of Québec. Of the three watersheds, the PMF always occurs at the end of winter-spring season when the snow accumulation is the greatest.Résumé: Quand la température atmosphérique à la surface a des augmentations en raison du réchauffement climatique mondial, la capacité des niveaux atmosphériques inférieurs à contenir de la vapeur d’eau s’élève. Ceci peut influencer les précipitations et les inondations. C’est pourquoi le réchauffement mondial conduit au changement climatique. Les précipitations extrêmes et les inondations extrêmes peuvent potentiellement subir des changements, à savoir, la précipitation maximale probable (PMP) et la crue maximale probable (CMP). Cette recherche vise à analyser les influences du changement climatique sur la PMP et la CMP dans trois bassins versants avec différentes conditions climatiques à travers la province de Québec, Canada. Les bassins versants sont situés dans le sud, le centre et le nord du Québec. Ils ont été sélectionnés d’une manière qui reflète la diversité du climat à travers le Québec. Afin d'étudier les conditions du changement climatique, les sorties du modèle régional canadien du climat (MRCC) ont été utilisées. Cette base de données couvre un horizon de temps à partir de 1961 jusqu'à 2100. Les données comprennent la précipitation quotidienne, la température, l'humidité spécifique et l’énergie potentielle de convection disponible (EPCD). Ces données ont été utilisées pour estimer la PMP. La méthode de l’Organisation Météorologique Mondiale (OMM) a été adaptée pour estimer les valeurs de la PMP dans des conditions de changements climatiques. L'eau précipitable centennale (W100) a été choisie comme une limite supérieure de l'eau précipitable pour déterminer le rapport de maximisation. Les séries chronologiques pour estimer W100 ont été établies à partir de valeurs annuelles maximales d'eau précipitable qui sont associées à des valeurs de variables atmosphériques similaires à l'événement qui doit être maximisé. Les variables atmosphériques utilisées dans cette recherche sont la température atmosphérique à la surface et l'EPCD. Cette méthode ne nécessite pas de fixer une limite supérieure au rapport de maximisation et est donc plus propice à la détermination de la PMP dans un contexte des changements climatiques. La PMP résultante a été utilisée pour forcer un modèle hydrologique distribué afin d’estimer la CMP. Les valeurs de la PMP et de la CMP ont été estimées en trois horizons de temps: le passé récent, les futurs proches (2030) et lointains (2070). Dans les régions où la fonte des neiges joue un rôle clé dans le cycle hydrologique annuel, les crues printanières en climat actuel correspondent habituellement au débit maximum annuel. La PMP et la CMP ont cependant été analysées séparément en deux saisons: l'été-automne (sans neige) et l'hiver-printemps (accumulation et fonte de neige) pour évaluer l’impact des changements climatiques sur la saisonnalité de ces événements extrêmes. La plus grande valeur obtenue a été identifiée comme la PMP / CMP annuelle. La CMP d’été-automne a été estimée par l'insertion de la PMP pour chaque jour de l'horizon de temps de simulation. Par conséquent, toutes les conditions possibles d'humidité du sol avant l’événement de la PMP ont été incluses. En conséquence, une distribution des valeurs de CMP basées sur différentes conditions initiales (niveaux d'humidité du sol) a été obtenue. La CMP d’hiver-printemps a été estimée en insérant la valeur de PMP à la fin d'une période de fonte et une accumulation de neige extrême. Nos résultats montrent que dans le sud et le nord du Québec, la CMP a toujours lieu à la fin de la saison hiver-printemps lorsque l’accumulation de neige est maximale. Aussi, la PMP et la CMP au sud du Québec devraient diminuer, mais la tendance au centre et au nord du Québec serait inversée. Dans le centre et le nord, la CMP augmente de 22 et 21%, respectivement, à la fin du 21e siècle alors que pour la même période, CMP aurait une réduction de 13% dans le sud du Québec. La CMP annuelle de ces bassins versants se produit dans la saison hiver-printemps dans trois horizons temporels.