Um espectrômetro automático de correlação angular Ge(Li)-Ge(Li) foi desenvolvido. O espectrômetro é movido automaticamente, controlado um microcomputador. A correlação angular direcional gama-gama entre transições coincidentes dos níveis do ANTPOT100 RU, alimentados pelo decaimento ß+ e por captura de elétrons do ANTPOT 100 R foi medida. A fonte de ANTPOT 100 Ru foi produzida na reação ANTPOT 100 Ru (p, n) Rh POT. 100 utilizando o feixe de prótons do Acelerador cíclotron. Foram medidas 30 cascatas simples e 11 cascatas triplas produzindo como resultado a assinalação do spin e paridade dos estados de 1865 kev, 1881 kev, 2099 kev, 2167 kev, 2241 kev, 2517 kev, e 3070 kev e a determinação dos valores de mistura multipolar de 21 transições sendo que 12 delas pela primeira vez. Foi medido ainda o valor da razão de mistura multipolar Q POT. 2 (E0\\E2) da transição 2+ IND. 2 2+ IND. 2 / Knowledge of the spectral distribution of radiation emitted by radiodiagnostic units provides important information, which can be applied to the Quality Assurance and Radiological Protection programs. Detectors which utilize Silicon PIN Photodiodes have been increasingly used in recent years, due to their low cost and being worked with at room temperature, the liquid nitrogen containers used with Ge and Si(Li) detectors not being necessary. Although, initially, the PIN photodiodes have a poorer energy resolution, as compared with Ge detectors, it\'s good enough for most purposes. Moreover, the development of thermoelectrically cooled systems and low noise level pre-amplifiers have resulted in PIN photodiodes achieving comparable resolutions to Ge ones. This work seeks to establish the properties of detectors made with Silicon PIN photodiodes and to develop the correctional process of the raw specffa both for the efficiency of the detector and other relevant factors, with the aim of obtaining the true spectrum emitted by radiodiagnostic equipment. The radiation spectra of radiodiagnostic equipment experimentally obtained were compared with theoretical spectra calculated from a semi-empirical model. Furthermore, mammography x-ray spectra scattered by a breast simulator were obtained. As a direct application of these experimentally measured spectra, methodologies were developed to determine the peak kilovoltage (kvp) of X-Ray tubes, to be able to calibrate kVp meters, and the half-value layer (HW) of the beams of interest.

Neste trabalho estudamos a influência que os aditivos decanol e o anestésico local tetracaína (TTC) exercem sobre a estrutura de sistemas micelares. Foram estudadas particularmente a influência do decanol na estrutra das micelas do surfactante aniônico dodecil sulfato de sódio (SLS) e da TTC na estrutura micelar do SLS e do surfactante zwiteriônico N-hexadecil-N, N-dimetil-3-amônio-1-propanosulfonato (HPS). O estudo de soluções micelares concentradas (razão molar água:SLS, Mw= 45,2) do sistema binário SLS/água e do sistema ternário SLS/decanol/água por difração de raios X nas vizinhanças das transições de fase isotrópica (I) SETA hexagonal (Halfa) líqüido-cristalina indicam que existe um empacotamento das micelas em uma ordem hexagonal local na fase I do sistema binário, e a fase Halfa tem empacotamento típico de objetos finitos/rígidos. No sistema ternário, em contraste, o empacotamento é relaxado através de um crescimento micelar induzido pelo decanol e a fase Halfa, que ocorre a uma concentração molar decanol:SLS, Md = 0,20, tem um comportamento típico de objetos infinitos/flexíveis. Uma seqüência intrigante de fases HalfaSETA nemática cilíndrica (Nc) a Md= 0,25 foi também investigada e é atribuída a um efeito combinado de crescimento micelar e mudança na rigidez da micela, com aumento da quantidade de decanol. O subseqüente aumento em Md leva o sistema à transição de fase Nc SETA nemática discótica (Nd) (Md= 0,38), acompanhada de uma mudança de forma micelar cilindro SETA disco. A influência do decanol em soluções isotrópicas mais diluídas (Mw= 144,0) foi estudada por espalhamento de raios X a baixos ângulos (SAXS) e analisada através das funções distribuição de distâncias p(r) e da distribuição de densidades eletrônicas rô(r). Os resultados mostram que micelas esferoidais crescem por influência do decanol e mudam de forma esferoide SETA cilindro a Md= 0,20 e cilindro SETA disco a Md APROXIMADAMENTE IGUAL A 0,40. Portanto, tornou-se evidente que a evolução de forma micelar do SLS pela influência do decanol é governada pela energia de curvatura da interface polar/apolar, uma vez que o decanol prefere localizar-se em interfaces planas, e que as transições de fase líqüido-cristalinas dependem dessas mudanças, associadas a efeitos de ordem estrutural em soluções concentradas. A influência da TTC em micelas aquosas de SLS e HPS foi estudada pelas técnicas espectroscópicas de fluorescência e ressonância paramagnética eletrônica (RPE) e por SAXS. Os resultados de fluorescência indicam que a droga é incorporada nas micelas, sendo que a TTC protonada se localiza mais próxima à interface polar/a polar das micelas, enquanto que a desprotonada penetra mais o interior hidrofóbico. Os resultados de RPE concordam com estas observações e indicam um aumento na organização molecular das micelas de SLS com a incorporação do anestésico local. Este aumento é mais pronunciado para micelas compostas por SLS e TTC carregada. Por outro lado, não foi observada nenhuma alteração significativa na organização molecular de micelas de HPS por influência da TTC. Através dos resultados de SAXS não foi observada nenhuma alteração na dimensão e na forma micelar por adição gradual de TTC neutra em SLS ou carregada em HPS, até a razão molar TTC:SLS, \'M IND. TTC\'= 0,30. Já os resultados de SAXS para os sistemas compostos por SLS e TTC protonada evidenciam um crescimento de micelas elipsoidais prolatas com anisometria v APROXIMADAMENTE IGUAL A 1,5 a \'M IND. TTC\'= 0 para v APROXIMADAMENTE IGUAL A 1,8 a \'M IND. TTC\'= 0,20 e 0,30. Os resultados são discutidos em termos de alteração das forças envolvidas na formação micelar (eletrostáticas e hidrofóbicas) e da própria estrutura molecular da TTC. / The influence of the aditives decanol and the local anaesthetic tetracaine on the micellar structure of the anionic surfactant sodium dodecyl sulfate (SLS) and zwiterionic N-hexadecyl-N, N-dymethyl-3-ammonio-1-propane-sulfonate (HPS) has been studied. The study of concentrated micellar solutions (water:SLS molar ratio, Mw= 45.2) of the binary system SLS/water and ternary SLS/water/decanol through X-ray diffraction dose to the liquid-crystalline isotropic (I) \'SETA\' hexagonal (Halfa) phase transition indicates a local micellar hexagonal packing in the I phase in the binary system, whereas the Halfa phase exhibits a packing typic of finite/rigid objects. On the other hand, the ternary system presents a more relaxed packing through a micellar growth induced by decanol, and the Halfa phase, which occurs at the decanol:SLS molar ratio, Md= 0.20 has got a typical infinite/flexible objects behaviour. An intriguing Halfa \'SETA\' cilindric nematic (Nc) phase sequence was also investigated at Md= 0.25 and has been atributed to the combined effect of the micellar growth and change of rigidity with the increasing in decanol amount. A further increase in Md leads to the Nc \'SETA\' discotic nematic (Nd) transition (Md= 0.38), which is accompanied by the cylinder \'SETA\' disc change of form. The infiuence of decanol in more diluted solutions of SLS/water (Mw= 144.0) has been studied through small-angle X-ray scattering (SAXS) and analysed through the distance distribution function p(r) and electronic density distribution rô(r). The results show that the spheroidal micelles grow due to the influence of decanol, changing from spheroid to cylinder form at Md= 0.20 and from cylinder to disc at Md= 0.40. Therefore, it became evident that the evolution of the SLS micellar shape under the effect of decanol is dominated by the bending curvature energy from the polar/apolar interface, since the decanol prefers the flat interfaces, and the liquid-crystalline phase transitions depend on these changes of shape, associated to structural order effects in concentrated solutions. The influence of TTC on SLS and HPS micelles were studied through fluorescence and electronic paramagnetic resonance espectroscopic techniques as well as by SAXS. The fluorescence results indicate that the drug incorporates into the micelles in such a way that the protonated TTC is localized close to the polar/apolar interface, whereas the uncharged form penetrates deeper into the hydrophobic core, in SLS micelles. The EPR results agree with the above observation besides indicating an increase in the SLS micellar molecular organization as the local anaesthetic is incorporated. Such an increase is more pronounced for micelles composed of SLS and charged TTC. On the other hand, no meaningful alteration in the HPS micelles molecular organization was observed under the TTC influence. From the SAXS results, we have not detected any changes in the micellar dimension and shape by gradual addition of either neutral TTC in SLS or charged TTC in HPS up to the TTC:SLS molar ratio (\'M IND. TTC\') of 0.30. Conversely, the SAXS results for systems composed of SLS and charged TTC have shown a micellar growth of prolate ellipsoidal micelles from anisometry v APROXIMADAMENTE IGUAL A 1.5 at \'M IND. TTC\'= O to v APROXIMADAMENTE IGUAL A 1.8 at \'M IND. TTC\'= 0.20 and 0.30. The results are discussed in the view of alterations in the forces involved in the micellar auto-assembling (electrostatic and hydrophobic) and the TTC structure.

O objetivo do trabalho, foi o desenvolvimento de uma metodologia de preparação de amostras de ZnO e Zn(1-X)Co(X)O de alta pureza baseada no processo químico sol-gel, e a análise das mesmas com a técnica de Correlação Angular γ-γ Perturbada (CAP). As técnicas de Difração de Raios X e Microscopia Eletrônica de Varredura também foram utilizadas para a caracterização das amostras. Além disso, foram produzidas amostras de Zn(1-X)Co(X)O na tentativa de observar comportamento ferromagnético à temperatura ambiente, através da variação da concentração de Co com diferentes atmosferas e temperaturas de tratamento. As medidas de CAP foram realizadas em um espectrômetro γ com quatro detectores de BaF2, que possibilita a aquisição simultânea de 12 espectros de coincidências γ-γ atrasadas. O núcleo de prova utilizado foi o 111In → 111Cd, que possui cascata γ de 172 - 245 keV populado no decaimento do 111In por captura eletrônica. Os campos hiperfinos foram medidos a partir do nível intermediário de energia de 245 keV do 111Cd com spin I = 5/2 e T1/2 = 85 ns. Os resultados mostram, que a metodolo- gia desenvolvida é adequada para a produção das amostras, fato que é comprovado pela concordância dos valores obtidos com os reportados na literatura. / The aim of this work was the development of high-purity ZnO and Zn(1-X)Co(X)O sample preparation methodology based on sol-gel chemical process, as well as the analysis of these samples by means of Perturbed Angular γ-γ Correlation technique (PAC). Also, X-ray Diffraction and Scanning Electron Microscopy were used to characterize the samples produced. In addition, Zn(1-X)Co(X)O samples were produced in an attempt to observe ferromagnetic behavior at room temperature, through the variation of Co concentration, with different atmospheres and annealing temperatures. The PAC measurements were performed in a BaF2 four-detector γ spectrometer, which allows simultaneous acquisition of 12 γ-γ delayed coincidence spectra. 111In→111Cd nuclear probe was used for these measurements, which has γ cascade of 172 - 245 keV populated in the decay of 111In by electron capture. The hyperfine fields were measured from the intermediate energy level of 245 keV in 111Cd with spin I = 5/2 and T1/2= 85 ns. The results show that the developed methodology is suitable for the production of these samples, which is evidenced by the agreement with values reported on literature.

O presente trabalho estudou os efeitos das intera»c~oes hiper¯nas em dois sistemas de ¶oxidos: RCoO3 (R = Gd e Tb) com estrutura perovskita e ¯lmes ¯nos monocristalinos de HfO2 por meio da t¶ecnica de Correla»c~ao Angular Gama-Gama Perturbada (CAP), com o objetivo de fazer um estudo sistem¶atico do comportamento da varia»c~ao do gradiente de campo el¶etrico em fun»c~ao da temperatura. Para realiza»c~ao das medidas de intera»c~oes de quadrupolo el¶etrico utilizamos como de pontas de prova os n¶ucleos 111In ¡!111 Cd e o 181Hf ¡!181 Ta. As amostras de perovskitas foram confeccionadas por meio de um processo qu¶³mico denominado Sol-Gel e as an¶alises foram realizadas com aux¶³lio de difra»c~ao de raios-X. As pontas de prova foram inseridas nas solu»c~oes qu¶³micas durante o preparo das amostras. Os ¯lmes ¯nos foram fornecidos pelo Laborat¶orio de Intera»c~oes Hiper¯nas da Universidade de Lisboa e a ponta de prova de 181Hf foi ativada por meio da irradia»c~ao do ¯lme ¯no no reator IEA-R1 do IPEN no tempo adequado a espessura do ¯lme. As medidas foram realizadas na faixa de temperatura de 10 - 1560 K. Os resultados das medidas das amostras de perovskita indicam uma depend^encia do GCE com o s¶³tio de ocupa»c~ao dos ¶atomos da ponta de prova e uma varia»c~ao do GCE com a temperatura, que pode ser explicada por transi»c~oes de spins no ¶atomo de Co. As medidas do GCE dos ¯lmes ¯nos com mesma espessura apresentam uma segunda fra»c~ao, al¶em daquela correspondente a freqÄu^encia da HfO2 em amostras de bulk. / In the present work, the Perturbed Angular Gamma-Gamma Correlation technique (PAC) was used to measure the Electric Field Gradient (EFG) in two oxide systems: RCoO3 (R = Gd, Tb) perovskite oxide and HfO2 in order to study the behavior of the EFG as a function of temperature. Electric quadrupole hyper¯ne interaction measure- ments were carried out using 111In ¡!111 Cd and 181Hf ¡!181 Ta radioactive probe nuclei. The samples were prepared through a chemical route known as Sol-Gel technique and analyzed with x-ray di®raction. Both nuclei were introduced in to the perovskite samples during the chemical procedure. The thin ¯lms were provided by the Laboratory of Hyper¯ne Interactions at the University of 181Hf Lisbon and the probe nuclei was activated by the irradiation of the thin ¯lm in the reactor of IPEN IEA-R1 at an appropriate time regarding the thickness of the ¯lm. The measurements were taken in the temperature range from 4 K to 1560 K. The results for the perovskite oxides measurements show a site-dependence of the EFG with probe-nuclei occupation and a temperature dependence of EFG that can be explained if spins transitions in Co are considered. The results of EFG measurements in the 25 nm thin ¯lm of HfO2 show a second fraction besides that corresponding to bulk.

Xanthomonas citri subsp. malvacearum é o agente causal da mancha angular do algodoeiro, uma importante doença reportada em áreas de produção no Brasil e em todo o mundo. A partir da análise comparativa de sequências parciais do gene rpoB de linhagens de X. citri subsp. malvacearum, X. campestris pv. campestris, X. axonopodis pv. axonopodis e X. citri subsp. citri, desenhou-se o par de primers xam1R/2R. Foram testadas 19 espécies pertencentes ao gênero Xanthomonas, além de bactérias dos gêneros Acidovorax, Burkholderia, Erwinia, Pseudomonas e Ralstonia, e o produto de PCR específico de aproximadamente 560 pares de bases foi observado apenas para linhagens de X. citri subsp. malvacearum. Os primers desenhados mostraram-se altamente sensíveis, apresentando níveis de detecção de 8 ufc/ 5,0 L para suspensões da cultura pura da bactéria e 1,0 ng de DNA genômico de X. citri subsp. malvacearum. No isolamento, a partir de amostras de sementes sabidamente contaminadas, foram obtidas colônias bacterianas com características de morfologia e coloração semelhantes à X. citri subsp. malvacearum. Esses isolados foram submetidos a testes de coloração de Gram, hidrólise de amido, reação de hipersensibilidade (HR) em folhas de fumo e tomateiro, testes de patogenicidade em plantas de algodoeiro, amplificação com os primers específicos desenhados e sequenciamento do fragmento obtido e os resultados obtidos confirmaram a identificação dos mesmos como X. citri subsp. malvacearum. Experimentos combinados de BIO-PCR/nested-PCR foram realizados a partir do material obtido do processo de extração do patógeno das sementes contaminadas utilizando-se na primeira etapa de amplificação os primers correspondentes à parte do gene rpoB e na segunda etapa o produto da primeira amplificação e os primers específicos xam1F/2R. O resultado foi a observação de uma banda de aproximadamente 560 pb correspondente ao fragmento específico de X. citri subsp. malvacearum para todas as amostras testadas. Neste trabalho foi desenvolvido um teste de PCR específico para a detecção e identificação rápida e precisa dessa bactéria em amostras de sementes de algodoeiro. / Xanthomonas citri subsp. malvacearum is the causal agent of angular leaf spot of cotton an important disease reported in production areas in Brazil and worldwide. From the comparative analysis of partial rpoB gene sequences of X. citri subsp. malvacearum, X. campestris pv. campestris, X. axonopodis pv. axonopodis and X. citri subsp. citri strains, the pair of primers xam1F/2R was designed. Nineteen species of the genus Xanthomonas and isolates of the genera Acidovorax, Burkholderia, Erwinia, Pseudomonas and Ralstonia were tested and the specific PCR product of about 560 base pairs was observed only for strains of X. citri subsp. malvacearum. The primers were highly sensitive, with detection levels of 8 cfu/ 5.0 L for suspensions of pure culture of bacteria and 1.0 ng of genomic DNA of X. citri subsp. malvacearum. From contaminated seed samples, bacterial colonies were obtained with characteristic morphology and coloration similar to X. citri subsp. malvacearum. These isolates were tested for Gram stain, starch hydrolysis, hypersensitivity reaction (HR) on tobacco and tomato leaves, pathogenicity tests on cotton plants, amplification with the specific primers designed and sequencing of the fragment obtained. The results confirmed their identification as X. citri subsp. malvacearum. PCR experiments in combination of BIOPCR/ nested-PCR were performed with the material obtained from the extraction process of pathogen from seeds using in the first step of amplification primers corresponding to part of the rpoB gene and the second step the product of the first amplification and the specific primers xam1F/2R. The result was a band of approximately 560 bp corresponding to the specific fragment of X. citri subsp. malvacearum for all samples tested. In this work, a PCR test for the quick detection and accurate identification of this bacterium in seed samples of cotton were developed.

Studies aimed at the development of indigenous low cost star tracker and gyroless attitude and angular rate estimation is presented in the thesis. This study is required for the realization of low cost micro satellites. A target specification of determining the attitude with accuracy (3σ) of 0.05 degrees and attitude rate with accuracy (3σ) in the range of 50rad/sec at a rate of 10 samples/second in all the axes is set as a goal for the study. Different sensor arrays available in the market are evaluated on the basis of their noise characteristics, resolution of the analog-to-digital converter (ADC) present and ability to work in low light conditions, for possible use in the hardware realization of star tracker. STAR1000 APS CMOS array, manufactured by Cypress Semiconductors, qualified these performance criteria, is used for the simulation study. An algorithm is presented for scanning the sensor array, detection of star image and retrieving the information concerning the photoelectron counts corresponding to a star image. The exact designation of the center of the star image becomes crucial as it has direct implications on the accuracy of the estimated attitude. Various algorithms concerning the centroid estimation of a defocused star image on the sensor array to subpixel accuracy are studied and Gaussian Weighed Center of Gravity algorithm is adapted with some modifications and an accuracy of 0.039 pixels is obtained in both horizontal and vertical direction of the array. A one-to-one relationship is established between the stars obtained in the field-of-view (FOV) of the star tracker with the stars present in the star catalog resident in the star tracker through star identification algorithm. A star identification algorithm which relies on the interstar angles and brightness of the stars is developed in this thesis. The interstar angles of the stars visible in the FOV of the star sensor is recorded, compared with the inter-star angles made by the stars selected in the catalog, based on initial brightness match with stars formed on image plane. After identification at the initial epoch, consequent instants can drive information from the previous matches so as to decrease the computational complexity and storage requirement for the subsequent instants. The memory constraints and computational overhead on the processor and the dynamic range of the image detector used in the star tracker are the limiting factors. The stars thus identified with the stars in the catalog are used for the estimation of attitude. A point solution to the attitude estimation problem is computed using a least square based algorithm called ESOQ-2. The algorithm for centroiding of star images and ESOQ-2 for finding the point solution satellite attitude is coded and tested on Da Vinci based emulator. This exercise shows that it is possible to implement above algorithm for real time operations. Estimation of attitude at a given epoch using algorithms like ESOQ-2 does not minimize the noise and error covariance as the attitude estimated at each instant of time depends only on the measurement taken at that particular instant. So a Kalman Filter (KF) based estimation using Integrated Rate Parameter (IRP) formulation called SIAVE algorithm, is adapted, with some modifications, for the estimation of incremental angle and attitude rates from vector observations of stars. From the point solution of attitude estimation problem of the satellite, the incremental angle and angular rate at successive time steps are predicted using a linear KF and refined with the measurements from the stand alone star tracker, taken at discrete time steps, using the SIAVE algorithm. The sensor noise is modeled from the characteristics of STAR1000 sensor array used in the algorithm in order to make the simulations more realistic in nature. The optimality of Kalman filter is based on the assumption that the state and measurement noises are white gaussian random processes and the state dynamics of the plant is completely known. However, for most real systems, modeling uncertainties are present. So a robust state estimator based on H∞ norm minimization is devised. The H∞ filter, based on game theory approach is used to minimize the worst case variance of noise signals with the only assumption on the noise signals that they are energy bounded. The aim is to find the feasibility of using H∞ filter for the estimation of incremental angle and attitude rate of the satellite. The studies shows that H∞ filter with proper tuning can serve as potential estimation scheme for the attitude and angular rate estimation of the satellite. It is found that both Kalman filter and H∞ are able to meet the specified accuracy desired from low cost accurate star sensor.

‘Optical Caustics’ represent some of the most visually striking patterns of the light in nature.They occur when light rays from a source, such as the sun, get refracted, or reflected by curved media so as to bend and alter their path. They are ubiquitous and signify the regions of space in which many rays intersect to form bright singularities along a two-or a three-dimensional surface. The associated 2-D patterns (caustic patterns) could be simple or complex in ‘shape and size’ depending upon the optical arrangement used to produce them. Such patterns exhibit either a static or a dynamic behavior which can be controlled sensitively by the medium or the device used to produce them. The present thesis concerns with a few novel contributions in utilization of such optical caustics for the measurement of small angular rotation/tilt of objects. Utilizing a ‘hollow cylinder’ as a novel device for the generation of the optical caustics, the author proposed and demonstrated three new schemes of realizing a position-dependent-behavior of ‘Optical Caustic Patterns’. The said behavior is investigated both analytically as well as experimentally. The results of the investigation are then utilized to propose and demonstrate three methods of magnifying angular displacement of the hollow cylinder. The salient feature of the principle behind each of the said methods is illustrated in the figures below. The patterns in each of the above pictures correspond to two different positions of the hollow cylinder-the pattern in white color corresponds to the initial position while that in red color corresponds to new angular position of the cylinder. Defining S1 = ƒ (LΔΦ), S2= ƒ(TΔΦ) and S3= ƒ(ξ ΔΦ) as new signals from the proposed methods, it has been shown that each of them represent a magnified measure of the change in the angular position of the cylinder ΔΦ. Further, if a plane mirror is used in place of cylinder in the proposed methods, the corresponding signal S for the same change in the angular position ΔΦis represented by ΔD. For a chosen set of the experimental conditions, it is shown that for unit change in ΔΦ, the values of S1, S2 and S3 change 30, 37 and 62 times faster than ΔD. The investigations clearly demonstrate that hollow cylinders can be advantageously used as position-magnifying angle-sensing devices. The results of the investigations also suggest that in application areas such as auto collimation, torsion pendulum and design of motion control stages, this device is expected to bring in new advances.

Aufgrund ihrer herausragenden Eigenschaften haben ultrafeinkörnige Werkstoffe, die aus konventionellen normalkörnigen Halbzeugen über eine extrem große Kaltverformung hergestellt wurden, in den letzten zwei Jahrzehnten zunehmend an Bedeutung erlangt. In der vorliegenden Arbeit wird das Fließspannungsverhalten eines Reinaluminiumwerkstoffes (EN AW-1070 – Al99,7) und einer ausscheidungshärtbaren Aluminiumlegierung (EN AW-6060 – AlMgSi) mit Korngrößen von bis zu 660 nm und 310 nm in einem weiten Bereich von Dehnungen und Dehnraten analysiert und mit den zzt. existierenden Modellvorstellungen zu den mikrostrukturellen Abläufen in Verbindung gebracht. Um die Voraussetzung zur Herstellung von ultrafeinkörnigen Werkstoffen zu schaffen, wurden mehrere Werkzeugprototypen für die ECAP-Umformung im Labormaßstab entwickelt und erprobt. Die Untersuchungen zum Fließspannungsverhalten erfolgten anhand von Zug- und Druckversuchen über insgesamt sieben Dekaden der Dehnrate bis in den Bereich der hochdynamischen Belastung von 10^3 s^-1. Die Tests zeigen, dass das Fließspannungsverhalten ultrafeinkörniger Aluminiumwerkstoffe vollständig mithilfe der thermisch aktivierbaren Mechanismen erklärbar ist, wobei Ausscheidungen eine wichtige Rolle spielen. / Because of their exceptional properties ultrafine-grained materials, processed from conventional polycrystalline materials by severe plastic deformation, have gained increasing scientific and industrial interest during the last two decades. Based on the concept of work-hardening for f.c.c. metals the commercially pure aluminium AA1070 (Al99,7 – soft annealed) and the aluminium alloy AA6060 (AlMgSi – peak aged) were investigated. ECAP was used to introduce very high strains and an ultrafine-grained microstructure with grain sizes down to 660 nm and 310 nm. Subsequently compression and tensile tests were performed in a wide range of strain rates over seven decades up to the range of impact loading of 10^3 s^-1. The results indicate that strain path and the corresponding dislocation structure is important for the post-ECAP yielding and the following hardening response. Furthermore the precipitates of the AA6060 clearly constrain the interactions of dislocations in work-hardening stage III – causing lower strain rate sensitivity. If compared to the AA1070 they avoid hardening in stage V where an additional rate and temperature depending effect contributes – caused by the interaction of deformation induced vacancies and dislocations. The results indicate that the strain-hardening behavior can be described by thermal activated mechanisms.

The aim of this thesis is the modeling of surface directional thermal radiation and angular correction on the LST by using empirical and physical methods as well as the analysis of field validation. The work has conducted to some conclusions. The directional emissivity of natural surfaces was obtained from MODIS emissivity product and then used in the split-window algorithm for angular correction on LST. The parameterization models of directional emissivity and thermal radiation were developed. As for the non-isothermal pixels, the daytime-TISI method was proposed to retrieve directional emissivity and effective temperature from multi-angular middle and thermal infrared data. This was validated using an airborne dataset. The kernel-driven BRDF model was checked in the thermal infrared domain and its extension was used to make angular normalization on the LST. A new model, namely FovMod that concerns on the footprint of ground sensor, was developed to simulate directional brightness temperature of row crop canopy. Based on simulation result of the FovMod, an optimal footprintfor field validation of LST was obtained. This thesis has systematically investigated the topic of directional thermal radiation and angular correction on surface temperature and its findings will improve the retrieval accuracy of temperature and emissivity from remotely sensed data and will also provide suggestion for the future design of airborne or spaceborne multi-angular thermal infrared sensors and also for the ground measurement of surface parameters.

We present the theory of orbital angular momentum of light (MAO), based on the basic concepts of electromagnetism, as well as some techniques from generation and characterization of light beams possessing MAO. We also present non-linear optical processes of parametric conversion spontaneous descendant (CPD) and stimulated (CPDE). We reviewed the problem of conservation of MAO in CPD in the scheme does not collinear, describing States of using Laguerre-Gauss beams MAO. We extend this study to the case in which Bessel beams are used to describe the States of MAO. Our results show that rape occurs on conservation law of MAO, which is attributed to deformation of the angular spectrum of beam pumping (pump) transferred to the twin photons. However, this violation can be advantageous because through breach of MAO have access to entangled States of dimension greater than those generated with collinear geometry. As an alternative to the note of the violation of the law of conservation in parametric down conversion process we proposed an experiment based on CPDE, where the experimental implementation is simpler. Using MAO as target and polarization qubit as qubit control, we experimentally a alternative to optical circuit proposal for Li-Ping et al. [16] for the implementation of the logic gate C-NOT. Also we present an application of logic gate C-NOT for the generation of entangled States of a single photon, which can be implemented with our optical circuit. The generation of entangled States, multidimensional, and the implementation quantum logic gates are important for the areas of information and quantum computation. / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Apresentamos a teoria do momento angular orbital da luz (MAO), baseada nos conceitos básicos do eletromagnetismo, bem como algumas técnicas de geração e caracterização de feixes de luz possuindo MAO. Apresentamos também os processos ópticos não lineares de conversão paramétrica descendente espontânea (CPD) e estimulada (CPDE). Revisamos o problema da conservação do MAO na CPD no regime não colinear, descrevendo os estados de MAO utilizando feixes Laguerre-Gauss. Extendemos este estudo para o caso em que feixes Bessel são usados para descrever os estados de MAO. Nossos resultados mostram que ocorre violação na lei de conservação do MAO, que é atribuída a deformação do espectro angular do feixe de bombeamento (pump) transferido para os fótons gêmeos. Entretanto, esta violação pode ser vantajosa, pois através da violação do MAO conseguimos ter acesso a estados emaranhados de dimensão maior do que aqueles gerados com geometria colinear. Como alternativa para a observação da violação da lei de conservação no processo de conversão paramétrica descendente, propusemos um experimento baseado na CPDE, onde a realização experimental é mais simples. Utilizando o MAO como qubit alvo e a polarização como qubit controle, realizamos experimentalmente um circuito ótico alternativo à proposta de Li-Ping e colaboradores [16] para a implementação da porta lógica C-NOT. Também apresentamos uma aplicação da porta lógica C-NOT para a geração de estados emaranhados de um único fóton, que pode ser implementada com nosso circuito ótico. A geração de estados emaranhados multidimensionais e a implementaçãode portas lógicas quânticas são importantes para as áreas de informação e computação quântica.