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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.
31

Detekce ionizujícího záření pomocí Geiger-Müllerova detektoru / Detection of ionize radiation with Geiger-Müller tube

Dědina, Radim January 2008 (has links)
This work deals with problems related with detection and measuring of the ionisated radiation. First part of this work is devoted to theoretical problems of detection, particulary to measuring with Geiger Muller tubes. Second part of the work contains proposal of electronical circuit using Geiger Muller tube as well as description of results experimentally acquired while using the detector, which was manufactured according to the proposed scheme. On the basis of those results it appears that proposed apparatus can be used for significant indication range extension.
32

Was erzählt Fritz Kreislers Geige?

Santi, Matej 09 November 2020 (has links)
This short contribution shows the relevance of audiovisual sources for the history of 20th century music. It traces the role played by the violinist Fritz Kreisler (1875–1962) in shaping the widespread cliché of the “Viennese sound” via an examination of audiovisual sources. The sources stored in different online archives or social media portals play a key role, but the traceability of a given agent is not guaranteed. For this reason, controlled vocabularies and a digital tool which enable the addition of new metadata to already existing sources should be developed in the near future. This would enable researchers to trace agents, such as institutions and artists, and to connect them with places, repertoires and cultural topoi.
33

Globally Extended Kppen-Geiger Climate Classification and Temporal Shifts in Terrestrial Climatic Types

Rohli, Robert V., Joyner, T., Reynolds, Stephen J., Shaw, Cynthia, Vázquez, Javier R. 04 March 2015 (has links)
Increasing awareness of the impacts of global climate change on marine ecosystems and concerns about shifting bioclimatic and agricultural zones necessitate a reassessment of the geographical distribution of Earths climate types. In recent years, the availability of truly global data-sets has allowed for the application of climatic types, including the Kppen-Geiger system, over the oceans. This research uses NCAR Reanalysis data to create a global Extended Kppen-Geiger climate classification, including the world ocean, for the 1981-2010 averaging period. The percentages of Earths surface covered by tropical rainforest (Af), tropical monsoon (Am), and (especially) the mesothermal-mild summer (Cfc) climate types are much larger than in the terrestrial only analysis. Expanding and contracting terrestrial climate zones are also identified based on the differences in the total area through comparison with maps produced for 1901-1925, 1926-1950, 1951-1975, 1976-2000 and model-output-based predicted Kppen-Geiger types for 2076-2100. Results suggest that hot desert (BWh), hot semi-arid (BSh), and Af climatic types are projected to expand, while the tundra and most mesothermal and microthermal types will decrease in area. These results assist in projecting global impacts of climatic change.
34

Overlap of Global Köppen-Geiger Climates, Biomes, and Soil Orders

Rohli, Robert V., Joyner, T. Andrew, Reynolds, Stephen J., Ballinger, Thomas J. 04 March 2015 (has links)
Climate types, biome types, and soil orders are commonly used among physical geographers in research and to describe natural environmental characteristics. However, little attempt has been made to quantify the percentage of global land surface that is covered by combinations of climate types, biomes, and soil orders. This research overlays a world map of 31 climate types produced based on the Köppen-Geiger criteria using gridded NCAR/NCEP reanalysis monthly mean surface air temperature and precipitation data from 1981 to 2010 with global maps of eight biomes adapted from World Wildlife Federation and 12 soil orders from United States Natural Resources Conservation Service. Areas covered by each of the 2976 combinations are then calculated. Results suggest that, as expected, a few climate/biome/soil combinations are most common, such as desert climate/desert biome/entisols, tundra climate/tundra biome/gelisols, and desert climate/desert biome/aridisols. The local nature of soil properties causes small enclaves of unexpected combinations of climate, biome, and soils, and the 10 most extensive climate/biome/soil combinations occupy only one-quarter of the global land surface. The strong correspondence between climate and biome types validates the Köppen-Geiger criteria for categorizing climates based on vegetation realms, even today, despite the general paucity of data available when the criteria were established.
35

Der polnische Fidler Matthias Wantzke in Stettin 1606-1623: zum Problem der polnischen Geiger in den pommerschen Herzogtümern

Koch, Klaus-Peter 10 August 2017 (has links)
In den 1540er Jahren ist in der mitteleuropäischen Tanzmusik eine bemerkenswerte Entwicklung zu beobachten: In den Quellen, überwiegend Clavier- und Lautentabulaturen, treten in den Überschriften von Tänzen nunmehr nicht nur Typenbezeichnungen (wie Paduana, Galliarde, Menuet usw.) auf, sondern zunehmend auch Herkunftsbezeichnungen. Zu den frühen Bezeichnungen der letzteren Art gehören auch ' Polnischer Tanz', Moscabiter tantz, (Moskauer Tanz) und 'Ungarischer Tanz'. Vor diesem Hintergrund ist offenbar auch der Begriff 'polnische Geige', der in deutschen Quellen erstmals etwa gleichzeitig belegt ist, zu bewerten. Es bleiben also viele offne Fragen. Eines jedoch ist erkennbar: Im Musikleben der pommerschen Herzogtümer hatte die polnische Musik ihren besonderen Stellenwert.
36

Optimizing Performance of Coherent Lidar Systems Using Photon-Counting Arrays

Szymanski, Maureen Elizabeth 20 December 2022 (has links)
No description available.
37

SINGLE EVENT UPSET DETECTION IN FIELD PROGRAMMABLE GATE ARRAYS

Ambat, Shadab Gopinath 01 January 2008 (has links)
The high-radiation environment in space can lead to anomalies in normal satellite operation. A major cause of concern to spacecraft-designers is the single event upset (SEU). SEUs can result in deviations from expected component behavior and are capable of causing irreversible damage to hardware. In particular, Field Programmable Gate Arrays (FPGAs) are known to be highly susceptible to SEUs. Radiation-hardened versions of such devices are associated with an increase in power consumption and cost in addition to being technologically inferior when compared to contemporary commercial-off-the-shelf (COTS) parts. This thesis consequently aims at exploring the option of using COTS FPGAs in satellite payloads. A framework is developed, allowing the SEU susceptibility of such a device to be studied. SEU testing is carried out in a software-simulated fault environment using a set of Java classes called JBits. A radiation detector module, to measure the radiation backdrop of the device, is also envisioned as part of the final design implementation.
38

Analise de radionuclideos naturais e chumbo em produtos alimenticios e dietas

BUENO, LUCIANA 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:43:38Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:58:26Z (GMT). No. of bitstreams: 1 06651.pdf: 5564627 bytes, checksum: b77046c5c925821e357e7f104911efae (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP / FAPESP:97/00990-6
39

Analise de radionuclideos naturais e chumbo em produtos alimenticios e dietas

BUENO, LUCIANA 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:43:38Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:58:26Z (GMT). No. of bitstreams: 1 06651.pdf: 5564627 bytes, checksum: b77046c5c925821e357e7f104911efae (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP / FAPESP:97/00990-6
40

Modélisation de photodétecteurs à base de matrices de diodes avalanche monophotoniques pour tomographie d'émission par positrons

Corbeil Therrien, Audrey January 2013 (has links)
La tomographie d'émission par positrons (TEP) est un outil précieux en recherche préclinique et pour le diagnostic médical. Cette technique permet d'obtenir une image quantitative de fonctions métaboliques spécifiques par la détection de photons d'annihilation. La détection des ces photons se fait à l'aide de deux composantes. D'abord, un scintillateur convertit l'énergie du photon 511 keV en photons du spectre visible. Ensuite, un photodétecteur convertit l'énergie lumineuse en signal électrique. Récemment, les photodiodes avalanche monophotoniques (PAMP) disposées en matrice suscitent beaucoup d'intérêt pour la TEP. Ces matrices forment des détecteurs sensibles, robustes, compacts et avec une résolution en temps hors pair. Ces qualités en font un photodétecteur prometteur pour la TEP, mais il faut optimiser les paramètres de la matrice et de l'électronique de lecture afin d'atteindre les performances optimales pour la TEP. L'optimisation de la matrice devient rapidement une opération difficile, car les différents paramètres interagissent de manière complexe avec les processus d'avalanche et de génération de bruit. Enfin, l'électronique de lecture pour les matrices de PAMP demeure encore rudimentaire et il serait profitable d'analyser différentes stratégies de lecture. Pour répondre à cette question, la solution la plus économique est d'utiliser un simulateur pour converger vers la configuration donnant les meilleures performances. Les travaux de ce mémoire présentent le développement d'un tel simulateur. Celui-ci modélise le comportement d'une matrice de PAMP en se basant sur les équations de physique des semiconducteurs et des modèles probabilistes. Il inclut les trois principales sources de bruit, soit le bruit thermique, les déclenchements intempestifs corrélés et la diaphonie optique. Le simulateur permet aussi de tester et de comparer de nouvelles approches pour l'électronique de lecture plus adaptées à ce type de détecteur. Au final, le simulateur vise à quantifier l'impact des paramètres du photodétecteur sur la résolution en énergie et la résolution en temps et ainsi optimiser les performances de la matrice de PAMP. Par exemple, l'augmentation du ratio de surface active améliore les performances, mais seulement jusqu'à un certain point. D'autres phénomènes liés à la surface active, comme le bruit thermique, provoquent une dégradation du résultat. Le simulateur nous permet de trouver un compromis entre ces deux extrêmes. Les simulations avec les paramètres initiaux démontrent une efficacité de détection de 16,7 %, une résolution en énergie de 14,2 % LMH et une résolution en temps de 0.478 ns LMH. Enfin, le simulateur proposé, bien qu'il vise une application en TEP, peut être adapté pour d'autres applications en modifiant la source de photons et en adaptant les objectifs de performances.

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