Le LAT est l'instrument principal du satellite Fermi et permet d'étudier le ciel en rayons gamma de 20 MeV à plus de 300 GeV. Sa sensibilité accrue a permis l'augmentation du nombre de sources détectées dans le domaine des hautes énergies. Une partie importante de celles-ci n'a pas de contrepartie connue et une étude multi-longueur d'onde est nécessaire afin de comprendre l'origine du signal observé. Dans un premier temps, cette thèse présente l'étude morphologique et spectrale détaillée de la source non-identifiée HESS J1745--303, qui a été découverte dans le domaine gamma par l'expérience H.E.S.S. en 2006 puis analysée spécifiquement dans un article de 2008, à l'aide des données du LAT. Deux sources ponctuelles situées à une localisation proche de HESS J1745--303 sont présentes dans le catalogue à deux ans de données de Fermi (2FGL) mais une analyse dédiée de cette région est néanmoins nécessaire vu sa complexité. Elle est en effet localisée à ~1° du Centre Galactique et à moins de 0.5° du pulsar de la Souris, les deux sources les plus brillantes en gamma dans cette région. Les différents processus d'émission de photons sont présentés dans un second temps. Leurs simulations permettent d'effectuer une étude approfondie de l'origine de l'émission détectée aux hautes et très hautes énergies par le LAT et par H.E.S.S. L'émission de cette source reste en effet encore énigmatique de nos jours et une étude multi-longueur d'onde est effectuée afin de contraindre les modèles d'émission.

The innovative design of flat panel volume computed tomography (CT) systems has recently led to the emergence of a wide spectrum of new applications for both diagnostic and interventional purposes, such as ultra-high resolution bone imaging, image guided interventions, dynamic CT angiography, and interventional neuroradiology. Most of these applications require low X-ray dose to limit potential harm to the patient. One of the main challenges of low dose imaging is to maintain a quantum noise limited system to achieve the highest possible signal to noise ratio (SNR) at a given dose. One potential method to achieve a quantum noise limited system is to employ a high gain detector. Current flat panel CT technology is based on indirect conversion detectors that contain a scintillator and hydrogenated amorphous silicon (a-Si:H) p-i-n photodetectors which have a gain below unity and require a specialized p-layer. In this thesis, an alternative detector to the p-i-n photodetector, which can achieve gain above unity and thus aid in achieving quantum noise limited systems is investigated for large area flat panel imaging. The proposed detector is based on amorphous selenium (a-Se). Amorphous selenium is the most highly developed photoconductor for large area direct conversion X-ray imaging and is still the only commercially available large area direct conversion flat panel X-ray detector. However, the use of a-Se for indirect conversion imaging has not been significantly explored. Amorphous selenium has field dependent mobility and conversion efficiency, which increase with increasing electric field. It is also the only large area compatible avalanche-capable material; a property that was discovered more than 30 years ago. This unique property could be leveraged to provide the gain necessary for low dose medical imaging applications. The only current commercial avalanche capable a-Se optical detector uses electron beam readout in vacuum, which is not large area compatible and makes integration with pixelated readout electronics challenging. The detector structure proposed in this research seeks to address the challenges associated with integration of an avalanche capable a-Se detector with large area X-ray imager. One important aspect in the development of a-Se avalanche detectors is reducing the dark current and preventing a-Se breakdown as the electric field across the device is increased. A high dark current reduces the dynamic range of the detector, it increases the noise level, and it can lead to crystallization of the detector due to joule heating. To overcome the dark current problem, different blocking layers that allow for integration with large area flat panel imagers were investigated. Experimental results from fabricated devices provided the basis for the choice of the most suitable blocking layer. Two device structures are proposed using the selected blocking layer, a vertical structure and a lateral structure, each having associated benefits and drawbacks. It was shown that introducing a polyimide blocking layer brought down the dark current more than four orders of magnitude at high electric fields and does not deteriorate the charge transport properties of the detectors. The polyimide blocking layer also greatly minimizes physical stress related crystallization in a-Se improving reliability. Gain above unity was observed in the vertical structure and the initiation of impact ionization was verified by performing time-of-flight experiments. Although impact ionization was not verified in the lateral structure, this device structure was found to be highly sensitive to ultraviolet light due to the absence of a top contact layer. Devices were fabricated on several different substrates, including a CMOS substrate, to demonstrate their integration compatibility with large area readout electronics. The exhibited performance of the vertical device structure demonstrates that it is a suitable alternative to the p-i-n photodetector for low dose imaging applications.

Gegenstand der vorliegenden Arbeit ist die ortsaufgelöste Untersuchung der Schichtdicke und der elektrischen Eigenschaften von Funktionsschichten in gedruckten Polymersolarzellen. Die massendrucktechnische Realisierung der großflächigen Polymersolarzellen mit dem Schichtaufbau Zink/ZnO/P3HT:PCBM/PEDOT:PSS erfolgt im Tief- und Siebdruckverfahren auf einem papierbasierten Bedruckstoff. Die gedruckten Funktionsschichten werden mit verschieden optischen und elektrischen Messverfahren charakterisiert und die Eignung der Verfahren wird diskutiert. Abschließend wird die gesamte Polymersolarzelle mit einer Kombination aus spektraler und elektrischer Messung positionsgenau untersucht. Dadurch kann ein Zusammenhang zwischen den Solarzelleneigenschaften und den ortsaufgelösten Messwerten aufgezeigt werden. / The aim of this work is the space-resolved investigation of the layer thickness and the electrical properties of functional layers in printed polymer solar cells. The realization of the large-area polymer solar cells with a layer structure of zinc/ZnO/P3HT:PCBM/PEDOT:PSS occurs by gravure and screen printing on a paper-based substrate. The printed functional layers are characterized by different optical and electrical measurement methods and the suitability of these methods is discussed. Finally, the complete polymer solar cell is examined dependent on a position by using a combination of spectral and electrical measurement techniques. With this analysis a correlation between the solar cell characteristics and the space-resolved measurements can be shown.

Submitted by Kilvya Braga (kilvyabraga@hotmail.com) on 2018-04-25T12:33:46Z No. of bitstreams: 1 BRUNO MOURA MIRANDA - DISSERTAÇÃO (PPGEG) 2015.pdf: 9948864 bytes, checksum: 4dfc5042bae3dedf54ac975413988ca9 (MD5) / Made available in DSpace on 2018-04-25T12:33:46Z (GMT). No. of bitstreams: 1 BRUNO MOURA MIRANDA - DISSERTAÇÃO (PPGEG) 2015.pdf: 9948864 bytes, checksum: 4dfc5042bae3dedf54ac975413988ca9 (MD5) Previous issue date: 2015-02-27 / O objetivo deste trabalho foi desenvolver um equipamento de injeção de resina para processar compósitos via moldagem por transferência de resina de uso laboratorial. Foi cumprida a seguinte metodologia: concepção, fabricação e testes no equipamento, testes de injeção nas estações de processamento, fabricação de placas compósitas e posterior caracterização. Os materiais utilizados nos experimentos foram: Manta de fibra de vidro (450g/m2), tecido básico de fibra de vidro (600 g/m2) e resina poliéster insaturada ortofitálica de média viscosidade Arazyn 1.0 #08 Ara Ashland ® e catalisador Butanox 50. Foram produzidas placas de pequena área, com dimensões de: 175x125x5mm e de grande área, com dimensões de: 340x340x5mm. Baseado nos experimentos resultados, conclui-se que foi possível o projeto, desenvolvimento e fabricação de um equipamento de injeção de resina por RTM de uso laboratorial, de baixo custo, com baixas perdas energéticas, para fabricação de compósitos com reforço dos tipos: manta e tecido, com diferentes gramaturas e pequena espessura. / The objective of this work was design a laboratorial Resin Transfer Moulding Equipment to process composites. The following methodology was fulfilled: Design and manufacture of the equipment, testing its process capabilities, injection tests in the processing stations, manufacturing of composite plates and further characterization. The materials used in the experiments were glass fiber mat (450g / m2), base glass fiber fabric (600 g / m2), a medium viscosity 1.0 Arazyn Ara Ashland ® # 08 unsaturated polyester resin and 50 Butanox. Small and large area plates were produced with dimensions of: 175x125x5mm and 340x340x5mm respectively. Based on the experiments results, it is concluded that it was possible the design, development and manufacture of a resin injection equipment RTM for laboratory use with low cost and low energy losses, for the manufacture of composites with two reinforcement kind: mat and fabric, with different weights and thin.

This work studies the influence of field effect on large area 2 dimensional ribbons of fluids. A fluid of choice is confined in the channel of a metal-insulator-channel-insulator-metal architecture and is subjected to constant (d.c) or alternating (a.c) fields (de-pending on the application) along with a pressure drive flow. A general fluid would be composed of molecules having certain polarizability and be a dispersion of non-ionic and ionic particulates. The field effect response under pressure driven flow for this fluid would result in electrophoresis, electro osmosis, dielectrophoresis, dipole-dipole interaction and inverse electro osmosis phenomena. Using some of these phenomena we study applications related to desalination and energy harvesting with saline water as the ex-ample fluid for the former case, and solution processed poly vinyldene fluoride (PVDF) for the latter case. The geometrical features of \large area" and the \ribbon shape" can be taken advantage of to influence the design and performance for both applications. With regards to desalination, it is shown via experiments and theoretical models that the presence of alternating electric fields aid in ion separation along the flow when the saline water is subjected to laminar flow. Moreover, the power consumption is low due to the presence of the insulator. An average of 30% ion removal efficiency and 15% throughput is observed in the systems fabricated. Both performance parameters are discussion can be improved upon with larger channel lengths. The \2-D ribbon" and alternating field effect aid in achieving this by patterning the randomly distributed ions in the bulk into a smooth sheet charge and then repelling this sheet charge back into the bulk. The electric field exhibited by this sheet charge helps trap more ion sheets near the interface, thereby converting a surface ion trapping phenomena (when d.c is used) to a bulk phenomena and thereby improving efficiency. With regards to energy harvesting, a solution of PVDF in methyl ethyl ketone and 1-methyl-2-pyrollidone is confined to the \2-D ribbon" geometry and subject to high d.c fields. This aids in combining the fabrication, patterning and poling process for PVDF into one setup. Since the shape of the ribbon is defined by the shape of the channel, the ribbons (straight or serrated) can be used to sense forces of various magnitudes. More importantly experiments and theoretical models are studied for energy harvesting. Since the ribbon geometry defines the resonant frequency, large PVDF ribbon can be used to harvest energy from low frequency vibrations. Experiments show that up to 60 microwatt power can be harvested at 200 Hz and is sufficient to supplement the power for ICs.

Experimental observations indicate the presence of attached, gravity induced, horizontal buoyant currents above large area fires. Their driving mechanism is indirect and resembles the one observed above heated horizontal plates. Classic plume modelling is satisfactory for providing information for the flow far from the source. In dealing with large areas and directing attention to the flow close to the source, the classic plume theory should fail because the radial pressure gradient that is responsible for the driving of the flow is squeezed in the long and thin classic plume assumption. For this we propose a new plume structure for the description of the buoyant flow above a circular region of large radius L as “The flow field must be divided into three regions. A region where the flow is predominantly horizontal and attached to the surface, a transition region from horizontal to vertical where separation of the attached current takes place, and a region where vertical flow is established and classic plume theory can be applied”. A model for the description of the gross properties of the horizontal currents is developed under the term “horizontal plume”. The modified Richardson number for the horizontal plume a, being analogous to the radius of the large area, is studied asymptotically in the limit a → ∞ and second order uniformly valid semi-analytical solutions are obtained. The hot plate experiment was set up in order to test the model and facilitate its improvement. A chapter is dedicated to the data analysis coming from thermocouple readings and visualisation of the flow using particle image velocimetry.In the remainder of this thesis two classic problems of laminar natural convection are revisited. That of the first order laminar boundary layer above an isothermal circular plate of radius a and the first order laminar boundary layer above the semi- infinite plate inclined to horizontal. In both cases allowances to variable property effects were made through the introduction of a nondimensional parameter λT, with its value set to zero implying the assumption of the Boussinesq approximation. For the circular plate, fourth order series solutions were obtained valid at the edge of the plate where the effects of λT and Prandtl number Pr are studied. Furthermore a finite difference scheme for the numerical solution of the nonsimilar partial integro- differential equation was developed using the Keller Box method and compared with results obtained from the commercial finite element software COMSOL Multiphysics 3.5a. For the semi-infinite plate, fourth order series approximations valid at the edge of the plate were obtained, while an extensive analysis for the effect of λT, Pr and inclination parameter σ was performed on the flow. Positions of the separation points when the inclination is negative (σ < 0) as a function of Pr and λT were recovered.

Cílem této práce je vývoj světelného zdroje založeného na technologii tlustostěnného elektroluminiscenčního panelu napájeného střídavým napětím (ACPEL). V současné době se jedná se o jedinou technologii založenou na metodách materiálového tisku vhodnou pro přípravu velkoplošných, flexibilních a vzorovaných zdrojů světla. Důraz je v této práci kladen na představení, prozkoumání a odstranění typických problémů, které jsou spojovány s touto technologií. Tyto problémy jsou omezený odstín barvy emitovaného světla a dlouhodobá stabilita elektroluminiscenčního prvku, který je vystaven vlivům prostředí. Rešeršní část dizertační práce je zaměřena na představení a identifikaci depozičních technik, vhodných pro reprodukovatelnou přípravu ACPEL panelů. Dalším cílem je identifikace fyzikálních parametrů, vhodných pro charakterizaci velkoplošných zdrojů světla. Praktickým cílem práce je nalezení vhodné metodologie pro popis a charakterizaci panelů, jakožto plošných světelných zdrojů. Fotometrická veličina jas L a spotřeba elektrické energie P byly vyhodnoceny jako vhodné parametry, určující aplikaci ACPEL panelů. Na modrém panelu bylo dosaženo maximální hodnoty jasu L = 133 cd•m2 při napětí Upp = 500 V a frekvenci f = 1000 Hz. Hodnoty spotřeby elektrické energie, vztažené na jednotkovou plochu panelů zkoumaných v této práci, jsou (7±3) mW. Tyto dosažené hodnoty dělají ze světelných zdrojů založených na ACPEL technologii zajímavé kandidáty pro různé aplikace. Vlivu rostoucí amplitudy a frekvence budícího napětí na dlouhodobou stabilitu panelů je důležitým cílem této práce. Pro popis stability byly zavedeny parametry L50 and L75. Bylo zjištěno, že rostoucí frekvence budícího napětí zkracuje životnost panelů. Laminovaný panel napájený napětím s přibližně trojnásobně vyšší frekvencí vykazoval přibližně třetinové hodnoty parametrů L50 a L75. Nejvyšších hodnot stabilitních parametrů dosahoval panel enkapsulován mezi skleněné pláty – přibližně sedminásobnou hodnotu oproti laminovanému panelu s trojnásobnou frekvencí. Optimální stability panelů lze dosáhnout při nastavení frekvence v rozmezí 400–800 Hz a zapouzdřením mezi sklo. Úzká paleta odstínů barev emitovaného světla je jeden z typických problémů, který dále zkoumán v dizertační práci. Tato práce zkoumá nadějnou metodu, přídavek vhodného materiálu pro konverzi barvy (CCM). Nový derivát diketopyrrolopyrrolu (DPP), absorbující v modré oblasti, byl přidán k modrému fosforu a byl pozorován sedminásobný narůst hodnot absolutního spektrálního ozáření v oblasti vlnových délek odpovídajících maximální emisi CCM materiálu. Jednoduchost přípravy vyvinutých zdrojů světla spolu s velmi nízkou spotřebou a vysokou dobou života dělají z ACPEL panelů zajímavé kandidáty pro podsvícení prvků například v automobilovém průmyslu, pro dekorativní osvětlení, pro „branding“ – zvýraznění reklamních značek.

This master's thesis addresses the processing of project documentation for construction of three storey, multifunctional house in Velké Opatovice. The building is designed on flat terrain, it is terrace graded to the east and south and has a warm flat roof. On the first floor there is a pharmacy, travel agency, textile shop and technical facilities of the building. On the second floor there is an office space for advertising and graphics company. The third floor is designed as a large-area apartment for a family of four.

Metrology is the science of measurement. It is also a prerequisite for maintaining a high quality in all manufacturing processes. In this thesis we will present the demands and solutions for ultra-precision metrology in the manufacturing of lithography masks for the TV-display industry. The extreme challenge that needs to be overcome is a measurement uncertainty of 10 nm on an absolute scale of more that 2 meters in X and Y. Materials such as metal, ceramic composites, quartz or glass are highly affected by the surrounding temperature when tolerances are specified at nanometer levels. Also the fact that the refractive index of air in the interferometers measuring absolute distances is affected by temperature, pressure, humidity and CO2 contents makes the reference measurements really challenging. This goes hand in hand with the ability of how to design a mask writer, a pattern generator with a performance good enough for writing masks for the display industry with sub-micron accuracy over areas of square meters.  As in many other areas in the industry high quality metrology is the key for success in developing high accuracy production tools. The aim of this thesis is therefore to discuss the metrology requirements of mask making for display screens. Defects that cause stripes in the image of a display, the so called “Mura” effect, are extremely difficult to measure as they are caused by spatially systematic errors in the mask writing process in the range of 10-20 nm. These errors may spatially extend in several hundreds of mm and are superposed by random noise with significantly higher amplitude compared to the 10-20 nm.  A novel method for measuring chromium patterns on glass substrates will also be presented in this thesis. This method will be compared to methods based on CCD and CMOS images. Different methods have been implementedin the Micronic MMS1500 large area measuring machine, which is the metrology tool used by the mask industry, for verifying the masks made by the Micronic mask writers. Using alternative methods in the same system has been very efficient for handling different measurement situations. Some of  the discussed methods are also used by the writers for calibration purposes. / QC 20110517

The methods of analysis with a focused ion beam, commonly termed as nuclear microscopy, include quantitative physical processes like PIXE and RBS. The element concentrations in a sample can be quantitatively mapped with a sub-micron spatial resolution and a sub-ppm sensitivity. Its fully quantitative and non-destructive nature makes it particularly suitable for analysing biological samples. The applications in biomedical research are manifold. The iron overload hypothesis in Parkinson\\\''s disease is investigated by a differential analysis of human substantia nigra. The trace element content is quantified in neuromelanin, in microglia cells, and in extraneuronal environment. A comparison of six Parkinsonian cases with six control cases revealed no significant elevation in iron level bound to neuromelanin. In fact, a decrease in the Fe/S ratio of Parkinsonian neuromelanin was measured, suggesting a modification in its iron binding properties. Drosophila melanogaster, or the fruit fly, is a widely used model organism in neurobiological experiments. The electrolyte elements are quantified in various organs associated with the olfactory signalling, namely the brain, the antenna and its sensilla hairs, the mouth parts, and the compound eye. The determination of spatially resolved element concentrations is useful in preparing the organ specific Ringer\\\''s solution, an artificial lymph that is used in disruptive neurobiological experiments. The role of trace elements in the progression of atherosclerosis is examined in a pilot study. A differential quantification of the element content in an induced murine atherosclerotic lesion reveals elevated S and Ca levels in the artery wall adjacent to the lesion and an increase in iron in the lesion. The 3D quantitative distribution of elements is reconstructed by means of stacking the 2D quantitative maps of consecutive sections of an artery. The feasibility of generating a quantitative elemental rodent brain atlas by Large Area Mapping is investigated by measuring at high beam currents. A whole coronal section of the rat brain was measured in segments in 14 h. Individual quantitative maps of the segments are pieced together to reconstruct a high-definition element distribution map of the whole section with a subcellular spatial resolution. The use of immunohistochemical staining enhanced with single elements helps in determining the cell specific element content. Its concurrent use with Large Area Mapping can give cellular element distribution maps.