Ce travail présente l'étude de faisabilité des mesures de transmission avec des échantillons MINERVE à l'installation de temps de vol GELINA. L'idée principale était de définir des procédures pour analyser les résultats des mesures de transmission réalisées avec des échantillons cylindriques ne répondant pas à la géométrie de transmission idéale. La capacité d'extraire des résultats fiables a été démontrée sur l'exemple des échantillons MINERVE enrichis en argent. De plus, des mesures de transmission et de capture avec des disques standards d'argent naturel ont été effectuées pour améliorer les paramètres de résonance pour 107Ag et 109Ag. Les principales étapes de ce travail sont la réduction des données brutes (taux de comptage) pour produire des spectres de transmission et de rendement de capture, puis l'analyse des spectres avec le code d'analyse de forme des résonances REFIT. / This work presents the feasibility study of transmission measurements with the MINERVE samples at time-of-flight facility GELINA. The main idea was to define procedures to analyse results of transmission measurements using cylindrical samples which do not fulfil the ideal transmission geometry. Capability of extracting reliable results was demonstrated on the example of MINERVE samples enriched in silver. In addition, transmission and capture measurements with standard discs of natural silver were performed to improve the resonance parameters for 107Ag and 109Ag. The main steps in this work are the data reduction of measured count rate spectra to produce final transmission and capture yield spectra and the spectra analysis with the resonance shape analysis code REFIT.

The use of short columns, higher carrier gas velocity and fast temperature programs in Comprehensive Two-Dimensional Gas Chromatography coupled to Time-of- Flight Mass Spectrometry (GC x GC/TOFMS) technique is expected to increase the speed of analysis up to several orders of magnitude when compared to conventional gas chromatography (GC) or gas chromatography/mass spectrometry (GC/MS). A systematic evaluation of the GC x GC/TOFMS configuration for high-speed applications has received little attention in the literature. The feasibility of High Speed Comprehensive Two-Dimensional Gas Chromatography coupled to Mass Spectrometry (High speed GC x GC/MS) for complex mixtures has been investigated in this thesis. A particular focus was placed on comparing conventional scanning quadrupole mass spectrometry (qMS) with a newly available non-scanning time-of-flight instruments (TOFMS). Experiments were carried out using GC/qMS, GC x GC/qMS, GC/TOFMS and GC x GC/TOFMS both in normal (slow) and fast temperature rates coupled with high frequency modulation in GC x GC. Initially a complex mixture consists of 24 semivolatile compounds was used as the analyte for the above purpose. In the initial experiments parameters like acquisition rate and duty cycle for qMS were determined to evaluate the effectiveness of the instrument for fast analysis. The practical duty cycle value obtained for the qMS was only about 18 % for single ion and one compound at a dwell time of 10 ms in SIM mode. In both high-speed GC/qMS and high-speed GC x GC/qMS techniques only about 40 % of the components in the complex mixture were found to be well separated. The acquisition rate of scanning instruments like qMS is incompatible for fast eluting peaks in high speed GC. TOFMS that has an acquisition rate of several hundred spectra per second offer the potential to define the fast GC peaks accurately. The high quality spectra from TOFMS also enable deconvolution of coeluting peaks in the complex mixtures. The advantage of the automated spectral deconvolution is demonstrated for the identification of the coeluting peaks in the complex mixtures. Coelution of peaks is also observed with highspeed GC/TOFMS technique. The high-speed GC x GC/TOFMS was also tested with two different analyte system ??? A pesticide mixture and platformate (an aromatic mixture) to evaluate the suitability for high-speed analysis of complex mixtures. A poor resolution was observed for the pesticide mixture in the two-dimensional plane and it appeared, as there was nearly no orthogonal separation in the second dimension. The platformate mixture displayed a better two-dimensional separation. Chromatographic peak resolution is not really a primary requirement for locating and identifying the coeluting compounds in high-speed GC x GC/TOFMS technique. However, it was observed that the high-speed GC x GC/TOFMS too faced problem to unscramble the mass spectra of those compounds with similar structure and sharing the same unique masses.

<p>An investigation was initiated, targeting snapshot 3D image sensors, with the objective to match the speed and resolution of a scanning sheet-of-light system, without using a scanning motion. The goal was a system capable of acquiring 25 snapshot images per second from a quadratic scene with a side from 50 mm to 1000 mm, sampled in 512×512 height measurement points, and with a depth resolution of 1 µm and beyond. </p><p>A wide search of information about existing 3D measurement techniques resulted in a list of possible schemes, each presented with its advantages and disadvantages. No single scheme proved successful in meeting all the requirements. Pulse modulated time-of-flight is the only scheme capable of depth imaging by using only one exposure. However, a resolution of 1 µm corresponds to a pulse edge detection accuracy of 6.67 fs when visible light or other electromagnetic waves are used. Sequentially coded light projections require a logarithmic number of exposures. By projecting several patterns at the same time, using for instance light of different colours, the required number of exposures is reduced even further. The patterns are, however, not as well focused as a laser sheet-of-light can be. </p><p>Using powerful architectural concepts such as matrix array picture processing (MAPP) and near-sensor image processing (NSIP) a sensor proposal was presented, designed to give as much support as possible to a large number of 3D imaging schemes. It allows for delayed decisions about details in the future implementation. </p><p>It is necessary to relax at leastone of the demands for this project in order to realise a working 3D imaging scheme using concurrent technology. One of the candidates for relaxation is the most obvious demand of snapshot behaviour. Furthermore, there are a number of decisions to make before designing an actual system using the recommendations presented in this thesis. The ongoing development of electronics, optics, and imaging schemes might be able to meet the 3D snapshot demands in a near future. The details of light sensing electronics must be carefully evaluated and the optical components such as lenses, projectors, and fibres should be studied in detail.</p>

<p>Today there are no fully general analytical techniques available for detection and confirmation of known and unknown substances in toxicological screening, further tools are therefore needed. The development of mass spectrometry with time-of-flight (TOF) detection is promising but there are still areas to be further developed and evaluated, both instrumentation and applications.</p><p>During 2009 The National Board of Forensic Medicine-Department of Forensic Genetics and Forensic Toxicology, (RMV) started cooperation with the instrumentation company Waters (Manchester, UK) and the Department of Clinical Pharmacology (KI, Solna) evaluating a new TOF-instrument for toxicological screening. My assignment as a part of this project has been to create a limited and relevant database of drugs and toxics in Excel, including monoisotopic mass, used when screening for pharmaceutical substances and their metabolites most probable to be found in Swedish autopsy material.</p><p>A limited database has been developed based on information from several sources, it ended up in 875 analytes and metabolites. A limited but complete database is more reliable in practise than a big database, by means of a lower frequency of isobars and more information included (e.g. retention time from liquid chromatography) making analysis faster. Commercial databases are generally theoretical, lacking information about for example retention time that often is an important criterion for identification.</p>

Diamond is a promising material for high-power, high-frequency and high- temperature electronics applications, where its outstanding physical properties can be fully exploited. It exhibits an extremely high bandgap, very high carrier mobilities, high breakdown field strength, and the highest thermal conductivity of any wide bandgap material. It is therefore an outstanding candidate for the fastest switching, the highest power density, and the most efficient electronic devices obtainable, with applications in the RF power, automotive and aerospace industries. Lightweight diamond devices, capable of high temperature operation in harsh environments, could also be used in radiation detectors and particle physics applications where no other semiconductor devices would survive. The high defect and impurity concentration in natural diamond or high-pressure-high-temperature (HPHT) diamond substrates has made it difficult to obtain reliable results when studying the electronic properties of diamond. However, progress in the growth of high purity Single Crystal Chemical Vapor Deposited (SC-CVD) diamond has opened the perspective of applications under such extreme conditions based on this type of synthetic diamond. Despite the improvements, there are still many open questions. This work will focus on the electrical characterization of SC-CVD diamond by different measurement techniques such as internal photo-emission, I-V, C-V, Hall measurements and in particular, Time-of-Flight (ToF) carrier drift velocity measurements. With these mentioned techniques, some important properties of diamond such as drift mobilities, lateral carrier transit velocities, compensation ratio and Schottky barrier heights have been investigated. Low compensation ratios (ND/NA) &lt; 10-4 have been achieved in boron-doped diamond and a drift mobility of about 860 cm2/Vs for the hole transit near the surface in a lateral ToF configuration could be measured. The carrier drift velocity was studied for electrons and holes at the temperature interval of 80-460 K. The study is performed in the low-injection regime and includes low-field drift mobilities. The hole mobility was further investigated at low temperatures (10-80 K) and as expected a very high mobility was observed. In the case of electrons, a negative differential mobility was seen in the temperature interval of 100-150K. An explanation for this phenomenon is given by the intervally scattering and the relation between hot and cold conduction band valleys. This was observed in direct bandgap semiconductors with non-equivalent valleys such as GaAs but has not been seen in diamond before. Furthermore, first steps have been taken to utilize diamond for infrared (IR) radiation detection. To understand the fundamentals of the thermal response of diamond, Temperature Coefficient of Resistance (TCR) measurements were performed on diamond Schottky diodes which are a candidate for high temperature sensors. As a result, very high TCR values in combination with a low noise constant (K1/f) was observed.

This thesis describes the final precision mass measurements with SMILETRAP I, where a relative precision of &lt; 1 ppb (10-9) was reached routinely, and the development of SMILETRAP II, aiming for measurements with &lt; 0.1 ppb relative precision. The emphasis of the thesis is on the implementation of new techniques for achieving this precision improvement with SMILETRAP II. The Ramsey multiple-pulse excitation technique was tested at SMILETRAP I, and a reduction of the statistical uncertainty by factor three could by verified. The technique was applied in the last measurement with SMILETRAP I on H2+ and D+ ions. From these measurements the proton mass was deduced with a relative error of 0.18 ppb. It was found that temperature dependent magnetic field oscillations limited us from reducing the uncertainties further. A technical achievement of reducing the peak to peak temperature oscillation in the trapping region of SMILETRAP II by a factor four is presented, which should give an extended observation time and likewise improved precision. The new SMILETRAP II super-conducting magnet, with a slightly stronger field of 5.8 T compared with the previous of 4.7 T, was installed and adjusted.  A careful field alignment and reduction of inhomogeneities was done for minimizing the disturbances of the cyclotron frequency for improved precision. In that attempt, the localization and control of the trapped ion motion is also important. Thus a new cooling trap was set up. In the spring of 2009 coherent axial motion of a confined ion cloud was discovered in the cooling trap. By observation of the axial oscillations we can see the effects of evaporative cooling in the reduction of the axial energy distribution. Storing the ions up to 1 s in the cooling trap reduces the energy distribution by a factor of five. Other remarkable results of the ion oscillations are also reported. / At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 1: In progress. Paper 3: Submitted.

A comparison of the composition and structure of carbon films deposited by ns and fs laser ablation of graphite is the subject of this thesis. In addition, the effect of irradiation on the surface of graphite has been investigated in detail. Laser-induced phase transitions from graphite to sp-bonded carbon and trans-polyacetylene chains as well as the formation of nano-diamond have been observed after irradiation with fs pulses. An optical orientation mechanism involving both electric and magnetic interactions is proposed to understand the formation of nano-stripes and other structures on irradiated graphite surfaces. These phenomena are not observed after nanosecond laser irradiation. Tetrahedral carbon (ta-C) films deposited at cryogenic temperatures using ns laser radiation consist of sub-micron graphitized grains embedded in a matrix of sp3-hybridized bonded carbon. Nano-buckling is evident in ta-C films deposited by fs ablation where the composition is found to consist of mixed sp, sp2, and sp3 – hybridized carbons species. It is found that the concentration of sp-bonded chains is negligible in ns-C films. Surface enhanced Raman spectroscopy has been used to characterize molecular species in ns and fs carbon films. Time of flight mass spectroscopy has been used to study plume species produced by laser ablation. It is also found that polyyne molecules can be formed by fs laser dissociation of small molecules in organic solvents. This process is accompanied by the deposition of hexagonal nano-diamond films on substrates placed near the laser focus during irradiation. This opens a new path in the synthesis of 1D conducting molecules and nano-diamond materials for nano-science applications. Quantum chemical calculations involving density functional theory (Gaussian '03) have been carried out in support of this work and have been used to study Raman and IR vibrational modes of several novel carbon molecules synthesized in ta-C films and in the liquid phase. These studies have been extended to assist in the identification of astronomical spectra.

A comparison of the composition and structure of carbon films deposited by ns and fs laser ablation of graphite is the subject of this thesis. In addition, the effect of irradiation on the surface of graphite has been investigated in detail. Laser-induced phase transitions from graphite to sp-bonded carbon and trans-polyacetylene chains as well as the formation of nano-diamond have been observed after irradiation with fs pulses. An optical orientation mechanism involving both electric and magnetic interactions is proposed to understand the formation of nano-stripes and other structures on irradiated graphite surfaces. These phenomena are not observed after nanosecond laser irradiation. Tetrahedral carbon (ta-C) films deposited at cryogenic temperatures using ns laser radiation consist of sub-micron graphitized grains embedded in a matrix of sp3-hybridized bonded carbon. Nano-buckling is evident in ta-C films deposited by fs ablation where the composition is found to consist of mixed sp, sp2, and sp3 – hybridized carbons species. It is found that the concentration of sp-bonded chains is negligible in ns-C films. Surface enhanced Raman spectroscopy has been used to characterize molecular species in ns and fs carbon films. Time of flight mass spectroscopy has been used to study plume species produced by laser ablation. It is also found that polyyne molecules can be formed by fs laser dissociation of small molecules in organic solvents. This process is accompanied by the deposition of hexagonal nano-diamond films on substrates placed near the laser focus during irradiation. This opens a new path in the synthesis of 1D conducting molecules and nano-diamond materials for nano-science applications. Quantum chemical calculations involving density functional theory (Gaussian '03) have been carried out in support of this work and have been used to study Raman and IR vibrational modes of several novel carbon molecules synthesized in ta-C films and in the liquid phase. These studies have been extended to assist in the identification of astronomical spectra.

Waterflood optimization via rate control is receiving increased interest because of rapid developments in the smart well completions and I-field technology. The use of inflow control valves (ICV) allows us to optimize the production/injection rates of various segments along the wellbore, thereby maximizing sweep efficiency and delaying water breakthrough. It is well recognized that field scale rate optimization problems are difficult because they often involve highly complex reservoir models, production and facilities related constraints and a large number of unknowns. Some aspects of the optimization problem have been studied before using mainly optimal control theory. However, the applications to-date have been limited to rather small problems because of the computation time and the complexities associated with the formulation and solution of adjoint equations. Field-scale rate optimization for maximizing waterflood sweep efficiency under realistic field conditions has still remained largely unexplored. We propose a practical and efficient approach for computing optimal injection and production rates and thereby manage the waterflood front to maximize sweep efficiency and delay the arrival time to minimize water cycling. Our work relies on equalizing the arrival times of the waterfront at all producers within selected sub-regions of a water flood project. The arrival time optimization has favorable quasi-linear properties and the optimization proceeds smoothly even if our initial conditions are far from the solution. We account for geologic uncertainty using two optimization schemes. The first one is to formulate the objective function in a stochastic form which relies on a combination of expected value and standard deviation combined with a risk attitude coefficient. The second one is to minimize the worst case scenario using a min-max problem formulation. The optimization is performed under operational and facility constraints using a sequential quadratic programming approach. A major advantage of our approach is the analytical computation of the gradient and Hessian of the objective which makes it computationally efficient and suitable for large field cases. Multiple examples are presented to support the robustness and efficiency of the proposed optimization scheme. These include several 2D synthetic examples for validation purposes and 3D field applications.

Generating in-between images from multiple views of a scene is a crucial task for both computer vision and computer graphics fields. Photorealistic rendering, 3DTV and robot navigation are some of many applications which benefit from arbitrary view synthesis, if it is achieved in real-time. Most modern commodity computer architectures include programmable processing chips, called Graphics Processing Units (GPU), which are specialized in rendering computer generated images. These devices excel in achieving high computation power by processing arrays of data in parallel, which make them ideal for real-time computer vision applications. This thesis focuses on an arbitrary view rendering algorithm by using two high resolution color cameras along with a single low resolution time-of-flight depth camera and matching the programming paradigms of the GPUs to achieve real-time processing rates. Proposed method is divided into two stages. Depth estimation through fusion of stereo vision and time-of-flight measurements forms the data acquisition stage and second stage is intermediate view rendering from 3D representations of scenes. Ideas presented are examined in a common experimental framework and practical results attained are put forward. Based on the experimental results, it could be concluded that it is possible to realize content production and display stages of a free-viewpoint system in real-time by using only low cost commodity computing devices.