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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
91

Le gaz dans les galaxies spirales de l'univers local : modélisation d'observations radio et étude des lois de formation stellaire dans les galaxies perturbées / The gas of spirals galaxies in the local universe : simulations of radio observations and study of the star formation laws in perturbed galaxies

Nehlig, François 28 September 2015 (has links)
Le milieu interstellaire (MIS) des galaxies spirales joue un rôle primordial dans l'évolution des galaxies. Nous nous sommes attachés au cours de cette thèse à caractériser le lien existant entre le MIS dans les galaxies spirales et l'efficacité de la formation stellaire. Dans une première partie, nous étudions la morphologie du disque de gaz atomique de la galaxie spirale fortement inclinée NGC 2683, à l'aide d'un modèle de déprojection de cubes de données radio. Cette étude permet notamment de rendre compte de l'histoire d'accrétion de gaz dans ce système. Dans une seconde partie, nous nous intéressons aux conséquences de la compression du MIS qui peut avoir lieu dans des galaxies situées dans des environnements denses. Notre approche fait usage à la fois de données multilongueur d'onde de galaxies subissant la compression de leur MIS (avec notamment de nouvelles observations millimétriques), de simulations dynamiques de ces galaxies ainsi que d'un modèle analytique donnant accès à la physique aux petites échelles. Notre thèse montre la complémentarité de l'utilisation d'observations, de la modélisation de ces observations et de simulations dynamiques dans l'étude du MIS des galaxies spirales. / The interstellar medium (ISM) of spiral galaxies plays a key role in galaxy evolution. Throughout this thesis we characterized the link between the ISM of spiral galaxies and the star formation efficiency. In a first part, we studied the atomic gas distribution of the highly inclined spiral galaxy NGC 2683, with a deprojection model of radio data cubes. This study gives insight on the gas accretion history in this galaxy. In a second part of this work, we examined the compression effects of the ISM, which occurs in galaxies located in dense environment. Our approach makes use of both a multiwavelength data set of galaxies enduring ISM compression (including new millimeter observations), and dynamical simulations of these galaxies combined with an analytical model which gives access to small scale physics. Our thesis shows the complementarity of high quality observations together with modelisation of these observations and dynamical simulations in the study of the ISM in spiral galaxies.
92

Fundamental Study on SiC Metal-Insulator-Semiconductor Devices for High-Voltage Power Integrated Circuits / 高耐圧パワー集積回路を目指したSiC金属-絶縁膜-半導体素子の基礎研究 / コウタイアツ パワー シュウセキ カイロ オ メザシタ SiC キンゾク - ゼツエンマク - ハンドウタイ ソシ ノ キソ ケンキュウ

Noborio, Masato 23 March 2009 (has links)
Kyoto University (京都大学) / 0048 / 新制・課程博士 / 博士(工学) / 甲第14628号 / 工博第3096号 / 新制||工||1460(附属図書館) / 26980 / UT51-2009-D340 / 京都大学大学院工学研究科電子工学専攻 / (主査)教授 木本 恒暢, 教授 鈴木 実, 教授 藤田 静雄 / 学位規則第4条第1項該当
93

Komparace funkcionality standardní BI platformy a BI modulu integrovaného v ERP systému / Comparison of functionality of the standard BI platform and BI module integrated in the ERP system

Fargačová, Tamara January 2018 (has links)
This master’s thesis deals with comparison of the standard Business Intelligence platform specifically IBM Cognos BI and BI module integrated in the ERP system QI. In the first part it defines basic concepts of this topic and describes the life cycle of business information systems with emphasis on Business Intelligence. In the next part current situation on the market of these platforms and BI tools which create management information systems is described. Both types of BI solutions are compared with concentration on standard functionality usage. It also describes their ability to analyze through using data warehouse technology, integration with third-party products and business and economic aspects.
94

Six month outcomes and immune signatures of children infected with SARS-CoV-2

Burns, Madeleine Dell 10 November 2021 (has links)
Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is a novel pathogen that emerged in December of 2019 and has since infected people of all ages around the world. Children with acute SARS-CoV-2 infection are largely spared of the severe disease seen in adults. However, a life-threatening, post-viral inflammatory condition known as Multisystem Inflammatory Syndrome – Children (MIS-C) develops in a small fraction of children four to six weeks after either past SARS-CoV-2 infection or exposure and is characterized by high fevers, significant gastrointestinal symptoms and severe cardiac complications. Little is known about the lasting immune profiles of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection in children, let alone the long-term effects of the disease in this population. This study presents clinical features and serologic immune profiles of forty-nine pediatric patients (ages 12.4 ± 6.7 years) enrolled in the Massachusetts General Hospital Pediatric COVID-19 Biorepository with previous diagnoses of SARS-CoV-2 infection or the COVID-19-related MIS-C. Thirty-two children ages 0-22 years completed a questionnaire which captured lingering clinical symptoms of COVID-19 and MIS-C at the follow-up timepoint. This questionnaire study revealed significant on-going symptoms in both cohorts, including respiratory, gastrointestinal, neurologic and cardiovascular symptoms. To characterize lasting immune responses following the acute presentation, serum antibodies to S, RBD and N proteins of SARS-CoV-2 were quantified at the follow-up timepoint in forty-nine pediatric patients with past COVID-19 or MIS-C at a mean follow-up timepoint of 6.56 ± 1.75 months. Serologic signatures against SARS-CoV-2 in COVID-19 and severe MIS-C patients were compared at acute illness and at follow-up timepoints. Anti-SARS-CoV-2 antibodies remained elevated over time showing adequate seroconversion. Interestingly, anti-SARS-CoV-2 IgA remained elevated in the vast majority of individuals at follow-up, suggesting continued antigen exposure and mucosal inflammation. This research elucidates whether children maintain antibody levels to SARS-CoV-2 over time and speaks to the differences in antibody recovery to baseline in COVID-19 and MIS-C patients. It also highlights the lingering symptoms in both the COVID-19 and MIS-C cohorts, and suggests the need for significant long-term follow-up in children months, or even years after resolution of acute illness or disease. In total, this study addresses the substantial gap in understanding of the recovery of the adaptive immune system after SARS-CoV-2 infection in children. / 2023-11-09T00:00:00Z
95

Diversité structurale des agrégats de carbone et d'hydrogène, implications pour les porteurs des bandes aromatiques infrarouges / Structural diversity of carbon and hydrogen clusters, implications for the Aromatic Infrared Bands carriers

Bonnin, Maëlle 05 June 2018 (has links)
L’émission IR de nombreuses lignes de visée dans le milieu interstellaire (ISM) présente des bandes d’émission appelées AIBs, habituellement attribuées aux hydrocarbures aromatiques polycyliques (PAHs). Identifier les porteurs des AIBs permettrait une meilleure compréhension de l’évolution de la matière carbonée dans l’ISM. Le but est ici de pouvoir comparer les AIBs avec des spectres IR théoriques et expérimentaux de nanoparticules hydrocarbonées. Le travail réalisé ici a porté sur l’analyse structurale de ces systèmes. Des systèmes moléculaires désordonnés contenant de 24 à 60 atomes de carbone sont générés par des simulations Monte Carlo par échange de répliques à l’aide du potentiel réactif empirique AIREBO. Après minimisation de leur énergie potentielle, les structures ainsi créées sont caractérisées à l’aide de divers paramètres d’ordre. L’évolution de l’organisation structurale est analysée en fonction de la taille et de la composition chimique (rapport C/H) des systèmes. Les structures obtenues présentent une grande diversité. L’étude statistique des différents paramètres d’ordre permet de mettre en évidence des tendances. La forme globale prise par les agrégats dépend de leur taille. Les atomes d'hydrogène, souvent périphériques sur les structures de type cage, favorisent un degré d'organisation plus fort. Le calcul des spectres IR de ces structures sera réalisé dans le futur. Pour obtenir des spectres expérimentaux de nanoparticules hydrocarbonées en phase gaseuse, le développement du spectromètre en émission IR FIREFLY a été poursuivi et FIREFLY a été couplé avec une source de nanoparticules. Ces développements permettront bientôt de mesurer les spectres expérimentaux des systèmes d’intérêt. / The mid-IR emission of many lines of sight in the Interstellar Medium (ISM) displays Aromatic Infrared Bands (AIBs) commonly attributed to Polycyclic Aromatic Hydrocarbons (PAHs). Identifying AIB carriers would allow for a clearer view of carbon matter evolution in the ISM. We intend to compare AIBs with theoretically derived and expermentally obtained IR spectra of hydrocarbon nanoparticles. The work done here focused on the structural analysis of such systems. Disordered molecular systems containing 24 to 60 C-atoms are generated by multi-tempering Monte Carlo simulations using the empirical potential AIREBO. After quenching the potential energy, the created structures are characterized with various order parameters. The evolution of the structural organization is analyzed as a function size and chemical composition (C/H ratio) of the systems. Generated structures display a great diversity, The statistical study of the order parameters shows tendancies. The global shape of the clusters depends on their size. H-atoms, often found on the edges of cage-like structures, favour a higher degree of organization. The calculation of IR spectra for those structures will be done in the future. To obtain experimental spectra of gas-phase hydrocarbon nanoparticles, the development of the IR emission spectrometer FIREFLY was continued. FIREFLY was coupled with a source of nanoparticles. Thoses developments will soon allow to measure experimental spectra of the molecular systems of interest.
96

A Clinical Differentiation of Multisystem Inflammatory Syndrome in Children (MIS-C) & Kawasaki Disease (KD)

Estes, Andersen, Macariola, Demetrio 18 March 2021 (has links)
INTRODUCTION: With the emergence of the COVID 19 pandemic, a new disease, Multisystem Inflammatory Syndrome in Children (MIS-C), had evolved. Increasing number of children are being reported to have MIS-C in the U.S. & worldwide. In the U.S. there are currently 2617 MISC cases reported. MIS-C & Kawasaki Disease (KD), have almost the same presentation, making clinical differentiation difficult. This study aims at differentiating KD & MIS-C which could assist clinicians to determine which one they could be dealing with in their practices. METHODS: Clinical features & laboratory values were collected from published studies found by queries on PubMed & other websites. Reported values were selected from published systemic reviews, meta-analyses, & large retrospective chart studies. RESULTS: In KD, the most prevalent clinical features are fever (100%) & the 5 KD-defining clinical features: oral mucosal changes (96.5%), rash (96%), non-purulent conjunctivitis (89%), extremity changes (75.6%), and cervical lymphadenopathy (62.7%). MIS-C also presents with fever (100%) but has lower prevalence of oral mucosal changes (23%), rash (38.2%), non-purulent conjunctivitis (44.0%), extremity changes (2.5%), & cervical lymphadenopathy (4%). MIS-C leads to higher rates of ventricular dysfunction (39.3%), myocarditis (23%), & shock. For cardiac biomarkers, MIS-C has elevated troponin I (x6 normal) & Beta Natriuretic Peptide (BNP) (x414 normal), while KD has elevations of troponin I (x1.9 normal) & BNP (x15 normal). MIS-C has higher elevations in ESR, CRP, and D-Dimer at x6, x30, and x40 from the normal values, respectively, while KD has elevations of x2.8, x2.1, x7.3 from the normal values, respectively. MIS-C is associated with neutrophilia, thrombocytopenia, & anemia in 22% of cases. KD is associated with mild neutrophilia & anemia. KD has thrombocytosis in the subacute phase (x1.46 normal). CONCLUSION: Our results demonstrated that there are overlaps & differences in clinical and laboratory features. Fever is present in both KD & MIS-C, however the 5 KD defining clinical features of KD are less frequent in MIS-C. MIS-C induces higher levels of troponin I & BNP, findings that could potentially explain for higher rates of ventricular dysfunction & myocarditis. MIS-C causes higher elevations in inflammatory markers & D-Dimers compared to KD. Uniquely, thrombocytopenia is commonly present in MISC rather than in KD. Differentiating KD & MIS-C can be challenging, but by focusing closely on the clinical & laboratory features, clinicians may be able to distinguish between the two &, therefore, deliver the most appropriate care to patients in their practices.
97

High-resolution simulations of two cold palaeo climates in Europe : MIS 3 and LGM

Strandberg, Gustav January 2015 (has links)
The study of past climate is important because it increases our understanding of how the climate system works. Past climate is often reconstructed by using proxies (that is observations of things that tell something about past climate, for example tree rings, pollen in lake sediments and fossils). Model simulations of past climate further increases the knowledge since it has the possibility to gap the space and time between the sparse and scattered proxy observations, since a model simulation gives relatively continuous information about the whole simulated area. Model simulations can also give internally coherent information about parameters that is not easily reconstructed from proxies (for example heat fluxes).  In this thesis two periods in the past are simulated by climate models: the Marine Isotope Stage 3 (MIS 3), 44 000 years ago, and the Last Glacial Maximum (LGM), 21 000 years ago. Both periods are characterised by low temperature, low sea level and low level of carbon dioxide. The topography in northern Europe is dominated by ice sheets covering Iceland, Norway and parts of Sweden at MIS3; and more extensive ice sheets covering Iceland, Scandinavia, the British Isles and Northern Germany at LGM. These periods are firstly simulated by a global climate model. Those simulations are subsequently used in a regional climate model to increase the level of detail over Europe. To make the regional climate model simulation more realistic vegetation simulated by a dynamical vegetation model is used in the regional climate model.   The climate models simulate European climates much colder than today, especially at LGM. The temperature differences ranges from 5 to 45 °C colder than today; the largest differences being at the ice sheets where the perennial ice cover and the high altitude keep temperatures low. Precipitation is reduced with as much as almost 100 % in northern Europe due to reduced evaporation. Precipitation is increased with as much as 100 % in parts of southern Europe due to changes in atmospheric circulation. The simulations are in broad agreement with proxies, although there are differences.  The vegetation model simulates tundra like vegetation (herbs and shrubs) in the ice-free parts of central and southern Europe. The eastern parts of Europe are dominated by needle-leaved trees. The short and cool summers limit vegetation. The simulated vegetation is in broad agreement with reconstructions. Sensitivity studies of vegetation show that changed vegetation can change the monthly mean temperature with 1-3 °C in some seasons and regions. The response depends on regional surface characteristics. Sensitivity studies of ice sheets show that the simulated climate is consistent with the assumptions about the ice sheet extent made in the simulation. The simulated climate is cold enough in northern Europe to support the ice sheet, and warm enough in southern Europe to prevent the ice sheet from expanding in this direction. A removal of the ice sheet would only have an effect on the local scale in the vicinity of the ice sheet, but this experiment did not include changes in the large-scale global atmospheric circulation.  Although the regional climate model simulations are to a large degree depending on the global climate model simulations they provide new information. When comparing proxies with model data or studying local/regional climatic features (such as the interplay between climate and vegetation) high horizontal resolution, as in the regional climate model, is important. / Studiet av klimat i det förgångna är viktigt eftersom det ökar vår förståelse för hur klimatsystemet fungerar. Förgånget klimat rekonstrueras ofta med hjälp av proxies (det vill säga observationer av saker som säger något om klimatet förr i tiden, till exempel trädringar, pollen i sjösediment och fossiler). Modellsimuleringar av förgånget klimat ökar kunskapen ytterligare eftersom det ger en möjlighet att fylla i luckorna, i tid och rum, mellan de glesa och spridda proxy-observationerna, eftersom en modellsimulering ger information om hela det simulerade området. Modellsimuleringar kan också ge information om parametrar som inte så lätt rekonstrueras från proxies (till exempel värmeflöden).   I denna avhandling simuleras med klimatmodeller två perioder i det förgångna: MIS 3 (Marine Isotope Stage 3), för 44 000 år sedan och LGM (Last Glacial Maximum), för 21 000 år sedan. Båda perioderna kännetecknas av låg temperatur, låg havsnivå och låg halt av koldioxid. Topografin i norra Europa domineras av istäcken som täcker Island, Norge och Sverige vid MIS 3; och istäcken över Island, Skandinavien, Brittiska öarna och norra Tyskland vid LGM. Dessa perioder simuleras först av en global klimatmodell. Simuleringarna används senare i en regional klimatmodell för att öka detaljgraden över Europa. För att göra den regionala klimatmodell-simuleringen mer realistisk så används i den regionala klimatmodellen vegetation som är simulerad av en dynamisk vegetationsmodell. Klimatmodellerna simulerar europeiska klimat som är mycket kallare än dagens, särskilt vid LGM. Temperaturdifferensen spänner från 5 till 45 °C kallare än idag; de största skillnaderna är vid istäckena där det ständiga istäcket och den höga altituden håller temperaturen nere. Nederbörden minskar med så mycket som nästan 100 % i norra Europa på grund av minskad avdunstning. Nederbörden ökar med så mycket som 100 % i delar av södra Europa på grund av förändringar i atmosfärens cirkulation. Simuleringarna stämmer i stora drag överens med proxies, även om det finns skillnader.  Vegetationsmodellen simulerar tundralik vegetation (örter och snår) i de isfria delarna av centrala och södra Europa. De östra delarna av Europa domineras av barrträd. De korta och kalla somrarna begränsar vegetationen. Den simulerade vegetationen stämmer i stora drag överens med rekonstruktionerna. Känslighetsstudier av vegetationen visar att förändrad vegetation kan förändra månadsmedeltemperaturen med 1-3 °C i vissa regioner och under vissa säsonger. Responsen beror på regionala egenskaper vid markytan. Känslighetsstudier av istäckena visar att det simulerade klimatet är förenligt med de antaganden av istäckenas utbredning som görs i simuleringen. Det simulerade klimatet är tillräckligt kallt i norra Europa för att göra ett istäcke möjligt, och tillräckligt varmt i södra Europa för att hindra istäcket från att växa i den riktningen. Om istäcket skulle tas bort skulle det bara ha en effekt på lokal skala i närheten av istäcket, men detta experiment innefattade inte förändringar i atmosfärens cirkulation. Även om de regionala klimatmodell-simuleringarna till stor del beror på de globala klimatmodell-simuleringarna så ger de ny information. Vid jämförelser av proxies och modelldata eller studier av lokala/regionala egenskaper hos klimatet (som växelverkan mellan klimat och vegetation) så är hög horisontell upplösning, som i en regional klimatmodell, viktigt.
98

“We are also just normal people, like everybody else.” : Young Jehovah’s Witnesses in Belgium and their Experiences of Others’ Conceptions About their Religion.

Andersson, Liselotte Erika January 2022 (has links)
This study examines young Jehovah’s Witnesses’ experiences of others’ conceptions of their religion in media and through real-life encounters, and how they think it affects their everyday life. To get an insight into their subjective experiences, this research applied a qualitative approach with an interpretivist epistemological standpoint and constructionism as an ontological position. The data was collected through individual semi-structured interviews through Zoom. The participants consisted of eight Jehovah’s Witnesses living in Belgium, in the age range 14 to 18. The data was analysed using thematic analysis while employing an inductive approach. Goffman’s (1990; 1967) theories of self-presentation and face-work is discussed in relation to the main the findings. Findings showed that young Jehovah’s Witnesses encountered portrayals of child abuse, blood transfusion, and negative humour, and portrayals that invoked positive emotions, and neutral and correct information, although some had never seen any kind of portrayals of their religion in the media. All of them had come across what they classed as misconceptions about non-celebrations and prohibitions, cultism, and refusal of medical treatments, which they perceived as inaccurate or partially inaccurate. Some positive conceptions they came across were that Jehovah’s Witnesses were perceived as kind, helpful, and respectful. They believed others’ conceptions of their religion to be a result of word of mouth and partially through media portrayals, rather than first-hand experiences. Furthermore, they believed that inaccurate information and misconceptions about their religion were widespread due to lack of knowledge and misguided or spiteful former Jehovah’s Witnesses. They were self-aware of how and where they express their religious beliefs in different social contexts. They employed various coping strategies, e.g., sharing their experiences with fellow believers, relying on their religious beliefs,trying to think differently about a negative situation to maintain their well-being or avoiding negative content on media.
99

MIS Tunnel Diodes: Application to Solar Energy Conversion

St-Pierre, J. A. 07 1900 (has links)
<p> The MIS tunnel solar cell has recently attracted most of the attention in the solar energy conversion field. Construction is very simple and eliminates the costly diffusion of dopants. As in the Schottky type, a metal of proper work function is chosen to induce an inversion layer at the surface of the semiconductor (Al in the case of p type Si). An ultra thin (< 1.5 nm) oxide between the semiconductor and the metal passivates the surface by reducing surface states while permitting tunneling from the semiconductor to the metal.</p> <p> Good fill factors (> .7) have been obtained but high reflectivity of the Al has reduced the current output. Open circuit voltages greater than .61 volts and short circuit current density of 21 ma/cm^2 have been measured. Experimental evidence of the presence of an oxide different from SiO2 within 1.4 nm of the surface will be given and related to the thickness variation of the open circuit voltage. A maximum in VOC around 1.4 nm was found. A maximum efficiency of 7% was achieved without anti reflexion coating and a curve factor of .81 was observed in one of the cells. A slight variation in efficiency with the cell area was also observed.</p> / Thesis / Master of Engineering (MEngr)
100

Strengthen Violinist's Artistry and Wellbeing through Body Mapping

Baboun Ghattas, Lourdina January 2023 (has links)
The master’s thesis explores the importance of our bodies as musicians in establishing the positive impacts of mindfulness on performance, particularly in terms of improving body mapping. Musicians are aware that holding extreme tension in their bodies can affect the quality of the music. Therefore, understanding the complex workings of our bones, muscles, and connective tissues while performing can provide deep explanations on how to reduce pain and tension that can be caused by poor posture, a lack of balance, restricted movement, and other related factors. The approaches taken in this thesis involve developing an awareness of the important joints and bones for violinists and understanding their functions during performances, as well as whether they are well mapped or mis-mapped. For the sounding part, my exam concert included Beethoven's "Kreutzer" violin sonata No. 9, Op. 47, in A minor, and Shostakovich's Piano Trio No. 2 in E minor. The reason for choosing these two pieces to be performed in one concert is because they demand a high level of stamina and muscle strength from the performers. / <p>Beethoven's "Kreutzer" violin sonata No. 9, Op. 47, in A minor.</p><p>Shostakovich's Piano Trio No. 2 in E minor.</p>

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