published_or_final_version / abstract / Chemistry / Doctoral / Doctor of Philosophy

published_or_final_version / Chemistry / Master / Master of Philosophy

Doctor of Philosophy / Department of Physics / Glenn Horton-Smith / In March 2012, the Double Chooz reactor neutrino experiment published its most precise result so far: sin[superscript]2 2theta13 = 0.109 +/- 0.030(stat.) +/- 0.025(syst.). The statistical significance is 99.8% away from the no-oscillation hypothesis. The systematic uncertainties from background and detection efficiency are smaller than the first publication of the Double Chooz experiment. The neutron detection efficiency, one of the biggest contributions in detection systematic uncertainties, is a primary topic of this dissertation. The neutron detection efficiency is the product of three factors: the Gd-capture fraction, the efficiency of time difference between prompt and delayed signals, and the efficiency of energy containment. [superscript]252 Cf is used to determine the three factors in this study. The neutron detection efficiency from the [superscript]252 Cf result is confirmed by the electron antineutrino data and Monte Carlo simulations. The systematic uncertainty from the neutron detection efficiency is 0.91% used in the sin[superscript]2 2theta13 analysis. The seasonal variation in detector performance and the seasonal variations of the muon intensity are described in detail as well. The detector stability is confirmed by observation of two phenomena: 1) the [electron antineutrino] rate, which is seen to be uncorrelated with the liquid scintillator temperature, and 2) the daily muon rate, which has the expected correspondence with the effective atmospheric temperature. The correlation between the muon rate and effective atmospheric temperature is further analyzed in this thesis to determine the ratio of kaon to pion in the local atmosphere. An upper limit on instability of the neutron detection efficiency is established in the final chapter. The systematic error, 0.13%, from the relative instability is the deviation of the calibration runs. This thesis concludes with the potential systematic errors of neutron detection efficiency and estimation of how these potential systematic errors affect the result of sin[superscript]2 2theta13.

Realizamos medidas de transmissão no infravermelho (médio e distante) e espelhamos Raman de amostras de GdAlO3 puras e dopadas com Eu+3 para estudarmos as bandas de absorção de fonons K=0 e as transições eletrônicas nos íons Eu+3. Conhecendo-se a simetria do GdAlO3 (D162h) pudemos, utilizando o método da correlação, calcular o número e a simetria dos modos vibracionais, bem como sua classificação em internos e externos. Os resultados experimentais mostram boa concordância com os teóricos e revelam que o GdAlO3 apresenta três regiões distintas no infravermelho, compostas de várias bandas de absorção. Os modos internos estão em torno de 670cm-1 (estiramento) e 480cm-1 (flexão) enquanto que os modos externos localizam-se em torno de 200cm-1. A interação dos estados eletrônicos do Eu+3 com o campo cristalino do GdAlO3 foi estudada inicialmente supondo um campo de simetria Oh e depois introduzindo a distorção ortorrômbica (Cs) de uma maneira perturbativa. Pudemos verificar que a dita distorção levanta totalmente a degenerescência dos níveis 7FJ (J=0,1,...,6) e torna as transições 7F0 → 7FJ permitidas. / IR and Raman measurements were carried out in pure and Eu+3 - doped GdAlO3 with the purpose of understanding their K=O phonom modes and the Eu+3 electronic transitions. Starting from the GdAlO3 symmetry, (D162h) the correlation method allows the classification of the number and symmetries of the modes, as well their assignment as either internal or external. Experimental and theoretical results are in good agreement and show three well defined absorption bands in GdAlO3. The internal modes are found to be located around 670cm-1 (stretching) and 480cm-1 (bending), while the external modes are around 200cm-1. The interaction of Eu+3 electronic states with the GdAlO3 crystal fields were studied by taking into account small perturbative orthorrombic (Cs) distorcion on a crystal field with symmetry Oh. This small distortion lifts completely the degeneracy of the 7FJ (J=0,1,...,6) levels and allows the 7F0 → 7FJ transitions.

Die vorliegende Arbeit beschäftigt sich mit der Synthese neuer heptadentater Liganden und deren Gd(III)- und Y(III)-Komplexen. Diese auf dem AAZTA-Grundgerüst basierenden Liganden sollten in 6-Position des Perhydro-1,4-diazepinrings über eine zusätzliche funktionelle Gruppe verfügen, wodurch eine kovalente Anbindung der entsprechenden Gd(III)-Komplexe an Makromoleküle, Polymere oder Peptide möglich wäre. Abschließend wurden die Protonen-Relaxivitäten der darge¬stellten Gd(III)-Komplexe bestimmt, und die Komplexe bezüglich ihrer Eignung als Kontrastmittel bei der MRI untersucht. / The present dissertation deals with the synthesis of new heptadentate ligands and their corresponding gadolinium and yttrium complexes. These ligands, based on the AAZTA framework, should bear an additional functional group in 6-position of the perhydro-1,4-diazepine ring to bind the respective Gd(III) complexes covalently to macromolecules, polymers or peptides. Finally the proton relaxivities of the synthesized Gd(III) complexes were determined in order to examine the complexes regarding their application as MRI contrast agents.

This thesis provides new evidence which contributes to a clearer understanding of the mixing history of the lunar soil, the interactions of cosmic rays with the lunar surface and any temporal and spatial variations in cosmic ray intensity at the lunar surface. The bombardment of the lunar surface by cosmic rays produces secondary neutrons which are thermalised by the lunar soil. These thermal neutrons are captured by trace elements with large neutron capture cross sections such as cadmium, gadolinium and samarium. Measurements by thermal ionisation mass spectrometry of the changes in the isotopic abundances of cadmium, gadolinium and samarium due to neutron capture are presented in this thesis. Evidence is also presented of the first observations of mass fractionation in cadmium in lunar soils.Changes have been observed in samples from the Apollo 14, 16 and 17 missions. In 114 [superscript 114]Cd/[superscript 113]Cd changes of 0.3% to 0.5% have been observed in lunar samples 60501,105, 65701,23 and 72161,73, of 0.4% and 0.8% in [superscript 158]Gd/[superscript 157]Gd in samples 14163,848 and 60501,105 and of 0.8%, 1.2% and 0.06% in [superscript 150]Sm/[superscript 149]Sm in samples 14163,848 and 60501,105 and 74220,125 respectively. This is the first time that neutron capture has been detected in cadmium. Mass fractionation effects of 0.30%, 0.53% and 0.54% per mass unit have been observed in lunar samples 60501,105, 65701,23 and 72161,73, the first cadmium mass fractionation observed in lunar soils. The cause of elemental mass fractionation on the Moon is not yet understood. These new data from cadmium, a volatile element with a large mass range from [superscript 106]Cd to [superscript 116]Cd is a valuable contribution to the debate.Thermal neutrons are captured preferentially at resonance energies of 0.03 eV by [superscript 155]Gd and [superscript 157]Gd, at 0.09 ++ / eV by [superscript 149]Sm and at 0.178 eV by [superscript 113]Cd. A comparison of the changes in [superscript 114]Cd/[superscript 113]Cd, [superscript 156]Gd/[superscript 155]Gd, [superscript 158]Gd/[superscript 157] and [superscript 15O]Sm/[superscript149]Sm due to neutron capture can therefore indicate the relative energies of the neutrons.Previous work has compared changes in [superscript 158]Gd/[superscript 157]Gd and [superscript 150]Sm/[superscript 149]Sm, this work extends the comparison with the new measurements of the changes in 114 [superscript 114]Cd/[superscript 113]Cd, This thesis shows that the intensity of the thermal neutrons peaks at a higher energy than the <0.1 eV assumed by Lingenfelter et al. (1972). The capture rate for gadolinium calculated by Lingenfelter, has been shown to be too high, this thesis shows that if a modified energy spectrum is considered, biased towards higher energies, it will bring the calculated neutron capture rate by gadolinium closer to the measured rates.The concentrations of cadmium, gadolinium and samarium in nine lunar samples have been measured for the first time by high precision isotope dilution mass spectrometry. Cadmium in 10017,341, 14310,615, 15041,188, 15059,240, 60501,105, 65701,23, 72161,73 and 74220,125 is 10.0_+0.2, 1.51_+0.02, 32.8+_0.6, 34.9+_0.3, 112+_2, 68.3_+0.8, 57.0+_0.6 and 300+_7 ppb respectively. Gadolinium concentrations of 21+_7 ppm in 14163,848, 3.26+_0.05 and 5.8_+0.3 ppm in 60501,105, and 8.1+_0.2 and 8.6+_0.1 ppm in 74220,125 are presented. Samarium concentrations of 24.3_+0.4 and 29.8_+0.5 ppm were found in 14163,848, 2.68+_0.04 and 14+2 ppm in 60501,105, and 6.3+_0.1 and 6.8+_0.1 ppm in 74220,125.The concentrations of cadmium, gadolinium and samarium in the seven geochemical reference materials BCR-1, BHVO-1, BIR-1, DNC1, MAG-1, PCC-1 and W-2 are also presented, some measured for the first ++ / time by isotope dilution mass spectrometry.

L'imagerie par résonance magnétique est une des méthodes de diagnostic les plus utilisées, aussi bien dans le domaine médical que dans les études précliniques. Cependant, la relaxivité des agents de contraste commerciaux ne représente qu'une fraction de la relaxivité prédite par la théorie et il est nécessaire d'optimiser les différents paramètres dont elle dépend pour atteindre des valeurs de relaxivité plus élevées : nombre de molécules d'eau en première sphère de coordination, vitesse d'échange de l'eau, dynamique de rotation du complexe, relaxation électronique, distance Gd(III)-proton. Dans ce travail, nous présentons la synthèse, la stabilité et la relaxivité des complexes de Gd(III) de deux séries de ligands tripodes dérivés de la 8-hydroxyquinoléine, basés l'une sur une plateforme 1,4,7 triazacyclononane, l'autre sur un pivot azote central. Ces complexes ont montré des stabilités comparables à celles des agents commerciaux, des valeurs de relaxivités élevées dans l'eau ainsi qu'en milieu biologique. L'utilisation de la 8-hydroxyquinoléine comme base des ligands a permis de sensibiliser le Nd(III) et l'Yb(III) pour la luminescence proche infrarouge, ouvrant la possibilité pour le développement de nouveaux systèmes bimodaux.

<p>Controlling the power flow in transmission systems has recently gained increased interest. The difficulties of building new lines and the pressure of having a high utilization of existing assets, makes the flexibility of grid systems increasingly important.</p><p>This master thesis work investigates induction regulators as control devices for active power flow in a transmission system. A small change in angle of the rotor affects both the amplitude and the phase of the voltage. The magnetic coupling in the induction regulator can be controlled by changing the permeability of a thermo magnetic material such as gadolinium and can hence give a second independent controlling parameter. An analytical model and calculations in the</p><p>FEM software AceTripleC together with Matlab, is used to simulate the influence of the regulators connected to a simple grid in case1, a 400 kV scenario and case 2, a 45 kV scenario.</p><p>The analysis was carried out on a small transmission system consisting of two parallel transmission lines connected to source and load. The induction regulators are connected to one of the parallel transmission lines. The regulators modelled in case 1 must be able to control the active power flow in the regulated line to vary between 50 and 150 % of the original power flow through this line.</p><p>This shall be done over a range of 0 to 800 MW transmitted power. The regulators modelled in case 2 must be able to control the active power flow in</p><p>the regulated line to vary between 0 and 30 MW, if this does not cause the power flow in the parallel line to exceed 30 MW. This shall be done over a range of 0 to</p><p>50 MW transmitted power.</p><p>The regulators are designed as small and inexpensive as possible while still fulfilling requirements regarding the active power flow controllability in the grid, current density in windings and maximum flux density in core and gap.</p><p>The results indicate that the size of the 400 kV solution has to be reduced to become competitive whereas for the 45 kV solution the relative difference to existing solution is smaller. Advantages with the proposed design over a phase shifting transformer are mainly a simpler winding scheme and the absence of a tap changer.</p>

Controlling the power flow in transmission systems has recently gained increased interest. The difficulties of building new lines and the pressure of having a high utilization of existing assets, makes the flexibility of grid systems increasingly important. This master thesis work investigates induction regulators as control devices for active power flow in a transmission system. A small change in angle of the rotor affects both the amplitude and the phase of the voltage. The magnetic coupling in the induction regulator can be controlled by changing the permeability of a thermo magnetic material such as gadolinium and can hence give a second independent controlling parameter. An analytical model and calculations in the FEM software AceTripleC together with Matlab, is used to simulate the influence of the regulators connected to a simple grid in case1, a 400 kV scenario and case 2, a 45 kV scenario. The analysis was carried out on a small transmission system consisting of two parallel transmission lines connected to source and load. The induction regulators are connected to one of the parallel transmission lines. The regulators modelled in case 1 must be able to control the active power flow in the regulated line to vary between 50 and 150 % of the original power flow through this line. This shall be done over a range of 0 to 800 MW transmitted power. The regulators modelled in case 2 must be able to control the active power flow in the regulated line to vary between 0 and 30 MW, if this does not cause the power flow in the parallel line to exceed 30 MW. This shall be done over a range of 0 to 50 MW transmitted power. The regulators are designed as small and inexpensive as possible while still fulfilling requirements regarding the active power flow controllability in the grid, current density in windings and maximum flux density in core and gap. The results indicate that the size of the 400 kV solution has to be reduced to become competitive whereas for the 45 kV solution the relative difference to existing solution is smaller. Advantages with the proposed design over a phase shifting transformer are mainly a simpler winding scheme and the absence of a tap changer.

The application of magnetic resonance imaging (MRI) to non-invasively assess disease biomarkers has been hampered by lack of desired contrast agents with high relaxivity, targeting capability, and optimized pharmacokinetics. We developed a novel MRI probe which targets HER2, a biomarker for various cancers and a target for anti-cancer therapies. This multimodal HER2-targeted MRI probe integrates a rationally designed protein contrast agent with a high affinity HER2 affibody and near IR dye. Our probe can differentially monitor tumors with different HER2 levels in both cells and xenograft mice. In addition to its 10-fold higher dose efficiency compared to clinically-approved agent DTPA, our developed agent also exhibits advantages in crossing the endothelial boundary, tissue distribution, and tumor tissue retention as demonstrated by even distribution of the imaging probe across the entire tumor mass. Additionally, a second series of protein contrast agents that included affibody against EFGR developed with the capability to specifically target EGFR. These contrast agents have been utilized to monitor drug treatments and quantitatively analyze biomarker expression level. Furthermore, we anticipate these agents will provide powerful tools for quantitative assessment of molecular markers, and improved resolution for diagnosis, prognosis and drug discovery.