Dynamic Nuclear Polarisation (DNP) was suggested for the first time by Albert Overhauser in early 1950s. In DNP experiments the polarisation from electrons can be transferred to nuclei by irradiation of the electron resonance line. There are several possible mechanisms for polarisation transfer that involve DNP in solid state depending on the width of the electron line in respect to the nuclear Larmor frequency. In this thesis, the efficiency of TEMPO radical (2,2,6,6 tetramethilpiperidine, 1 oxyl) for DNP is demonstrated in combination with nuclear polarisation transfer techniques for dissolution experiments. New cryo-probes were developed for DNP and cross polarisation (CP) for operation temperatures as low as 1.5 K. Two of them were designed for dissolution experiments. Some published sequences of nuclear polarisation transfer were tested at low temperatures and compared. Novel sequences were implemented for efficient CP in organic samples doped with TEMPO to allow for a consecutive dissolution experiment. The combination of DNP with new CP sequences at low temperatures, achieved at least twice the 13C polarisation obtained with DNP and in a substantially shorter time (between 5 to 10 minutes) in samples doped with TEMPO. The polarisation levels obtained in samples of [13C-1] labelled Na acetate in a few minutes was comparable to the polarisation obtained with trityl radicals in a few hours. In addition, another strategy was investigated by using brute force polarisation as a mechanism for achieving large levels of nuclear spin order. The problem presented by this method is the long relaxation time required to obtain the thermal equilibrium polarisation. By doping with lanthanides samples of [13C-1] labelled Na acetate in 1:1 glycerol-water, it was possible to obtain thermal equilibrium for a 13C spin system in less than one hour.

The microstructure of the lung is complex, containing many branching airways and alveolar sacs for optimal gas exchange. Lung diseases such as cystic fibrosis (CF), asthma, and emphysema lead to a destruction of this microstructure. As such, there is a growing interest in the early identification and assessment of lung disease using non invasive imaging techniques. Pulmonary function tests such as spirometry and plethysmography are currently used for this purpose but can only provide quantitative lung function measurements rather than direct measurements of lung physiology and disease. Computed tomography (CT) has also been used but due to risk of cell damage and mutation from the ionising radiation, long term monitoring of the lungs is severely constrained. Recently, new methods based on magnetic resonance imaging (MRI) have been developed to provide diagnostic imaging of the lung. Conventional MRI is not very well suited for lung imaging due to the very low proton density of the pulmonary airspaces. This problem can be overcome by making the patient inspire noble gases such as 3He whose polarisations have been vastly increased through optical pumping. Therefore 3He MRI permits a non-invasive determination of lung function. The high diffusion coefficient of 3He can be exploited to probe the microstructure of the lung. By measuring how fast 3He diffuses within the lung, the size of the lung microstructure can be assessed. Normally, the airspace walls impede the diffusion of the gas but for diseased lungs where microstructure has been destroyed, diffusion is less restricted and a higher apparent diffusion coefficient (ADC) is observed. The research conducted for this thesis focused on the measurement of ADC using three different MRI pulse sequences with each sequence being designed to assess the peripheral airspaces over different length scales. These sequences were then implemented on three different subject study groups.

Dynamic nuclear polarisation is a technique that allows one to increase the signal-to-noise ratio in an NMR experiment substantially, by transferring the inherently larger electron polarisation to the nuclei. Quantum mechanical models of this effect have thus far been limited to the description of only a few nuclei. This is due to the exponential scaling of the matrices involved in the description of the system. In this thesis methods of reducing the state space needed to accurately describe the simulation of solid effect DNP were explored and tested. Krylov Bogoliubov averaging has been used to remove high frequency oscillations from the system Hamiltonian and confine the trajectory of the dynamics to the zero quantum coherence subspace. Truncation of the basis spanning the Liouville space to low spin correlation orders has been tested and a condition for a minimum truncation level was found. A strategy based on a projection method, which allows one to describe the spin polarisation transient with multi-exponential functions, is introduced. This results in a linear scaling of the propagator with the number of spins. The influence of the parameters involved in the solid effect on the dynamics of the polarisation build up is discussed. The second part of this thesis is concerned with a novel approach to detecting fast molecular dynamics with the use of multiple RF receive and transmit coils. A proof of principle probe with two decoupled RF coils is presented, as well as a field map based shimming strategy and fast 2D data acquired with the probe. Lastly a probe with six RF coils, based on the design of the dual coil probe, will be presented, and initial data shown. The potential for using this probe in hyper-polarisation experiments for protein binding and folding studies will be discussed.

lack of consensus among the world researchers on the significance of Po-210 build up in lead cooled reactors. The second objective is to evaluate the advantages and disadvantages of selected candidate metal coolants. In addressing both objectives, the computer code ORIGEN was used. To establish the background basis for these assessments, fundamental concepts of reactor physics are reviewed and discussed.

In this thesis we study the neutron transport (Boltzmann transport equation) which is used to model the movement of neutrons inside a nuclear reactor. More specifically we consider the mono-energetic, time independent neutron transport equation. The neutron transport equation has predominantly been solved numerically by employing low order discretisation methods, particularly in the case of the angular domain. We proceed by surveying the advantages and disadvantages of common numerical methods developed for the numerical solution of the neutron transport equation before explaining our choice of using a discontinuous Galerkin (DG) discretisation for both the spatial and angular domain. The bulk of the thesis describes an arbitrary order in both angle and space solver for the neutron transport equation. We discuss some implementation issues, including the use of an ordered solver to facilitate the solution of the linear systems resulting from the discretisation. The resulting solver is benchmarked using both source and critical eigenvalue computations. In the pseudo three--dimensional case we employ our solver for the computation of the critical eigenvalue for three industrial benchmark problems. We then employ the Dual Weighted Residual (DWR) approach to adaptivity to derive and implement error indicators for both two--dimensional and pseudo three--dimensional neutron transport source problems. Finally, we present some preliminary results on the use of a DWR indicator for the eigenvalue problem.

This thesis is dedicated to reasearch in radiolabeling bile pigment bilirubin. Minority bilirubin present in the body the form unconjugated. In this work, it was crucial synthesize radiolabeled bilirubin which could be monitored by detector in vitro experiments. A possible further applications, such bilirubin would be detectable in vivo experiments using µ-PET/SPECT (micro- positron emission tomography/single photon emission computed tomography) . The aim of this thesis propose variation for possible signs of bilirubin radioisotopes and synthesis of bilirubin derivates suitable for radioactive labeling. Another objektive of this work is the synthesis and study of the well-known derivative ranarubin called bilirubin, which could potentially have very simile characteristics, such as bilirubin and therefore would be a good candidate for radioisotope labeling and study of biological systems.

>Magister Scientiae - MSc / Public concern about all radiation and radon exhalation from building materials has been highlighted recently. The purpose of this study is to address this public concern and to investigate the contribution of building materials to indoor radon levels. As in soil and rocks, radon gas is formed inside the building materials by decay of the parent nuclide 226Ra. It is not possible to determine the radon exhalation rate simply from the activity concentration of 226Ra, instead one must measure radon exhalation rates directly from the surface of the material. 222Rn has been identified as an important factor that could result in a health hazard by studies all around the world. The exhalation experiments were done at the UWC physics department, in the Nuclear Physics Lab. A RAD7 radon detector was used to measure the radon concentration in an air tight chamber that contained various building material samples. The RAD7 records the number of alpha particles with energy of 6.11 MeV which results from the decay of 218Po, the daughter of 222Rn. The RAD7 detector converts counts into Becquerel’s per cubic metre (Bq/m3). The building materials tested were the raw materials used in construction such as two different types of building sand, building stones, coarse aggregate, floor and roof tiles, various granites from across the world that were sourced locally and uranium bearing sandstone originating from a Beaufort-West prospecting site. Stones from this site were used as filler material in the construction of two farm houses. Most building materials were found to have a very low rate of radon exhalation. The only materials that had any significant radon exhalation were 2 granite samples with a maximum exhalation rate of 1.5 Bq.m-2.h-1 and the uranium bearing sandstone. It is safe to say that the overwhelming majority of building materials tested are safe to use but some granites may require further study. The uranium bearing sandstone is a definite radiation protection issue and should not be used in any construction.

O propósito deste estudo foi investigar o conhecimento de segmentos da população (constituídos por leigos, por estudantes e profissionais de áreas com possíveis aplicações da radioatividade) em relação aos benefícios da radiação ionizante sobre polímeros de embalagens para alimentos. As questões básicas aqui levantadas foram idealizadas para que suas respostas fornecessem parâmetros de análise para se afirmar ou negar que a população, de um modo geral, desconhece radioatividade e sua aplicação no campo dos alimentos e não se mostra preparada para mudar seus paradigmas, arraigados por impressões que persistem fortes de acidentes nucleares noticiados principalmente em mídia televisiva. Este estudo qualitativo é fundamentado por Bachelard (1996), que avulta a necessidade de uma preparação muito bem estruturada quando se quer extrair as verdades de classes que insistem, por vergonha de seu não-saber, em falsear respostas que, se sinceras, poderiam indicar importantes caminhos a se seguir pelo campo educacional para que se mudassem as características tão conhecidas neste país de um conhecimento de senso comum que ficou pouco ou nada científico. Portanto, este trabalho está norteado por um veio acadêmico que mostra, em seus objetos de pesquisa, elementos (questionários e entrevistas) necessários para que se possa conhecer a verdadeira opinião das pessoas frente à radioatividade. Infelizmente, as repostas não são animadoras, mostrando que há um grande desconhecimento mesmo dos profissionais, sobre o tema. Finalmente, o objetivo maior deste trabalho de pesquisa não foi somente uma investigação, mas a elucidação da necessidade de serem iniciadas ações educacionais que mudem a realidade que hoje se desenha neste país e que, somente com essa mudança, poderá haver, satisfatoriamente, pelo apoio e aceitação social, avanços significativos na área de tecnologia nuclear. / The purpose of this study was to investigate the level of knowledge of parts the population (represented by layman and students, and professionals who work in areas with possible applications of radioactivity) related to the benefits of ionizing radiation on polymer packaging foodstuff. The basic questions raised here were intended to prompt answers that could supply parameters of analysis to confirm or to deny that the population in general ignore radioactivity and its applications in the field of foodstuff, besides not appear to be prepared to shift its paradigms, deep-rooted by impressions that remain strong, which are fed by occurrences of nuclear accidents broadcast mainly through the television media. This qualitative study is grounded by Bachelard (1996), who emphasize the need of a well structured preparation when the aim is to extract the truths from classes that insist, for being shame of not knowing, in misrepresent answers, which otherwise sincere, could point important ways to be followed along by the education field to change well-known characteristics in this field of a knowledge, based on a common sense that became slightly or no scientific at all. Therefore, this work is guided by an academic bias that shows, in its objects of research, elements (questionnaire and interviews) necessary to find out the true beliefs of people on the radioactivity. Unfortunately the answers are not encouraging, showing that there is a huge unknowing, even from professionals, about the theme. Finally the major goal of this research has not been only an investigation, but the elucidation of the need to give start to educational actions that could change the reality that is drawn in this country today and, only through this change, it is possible to reach in a satisfactory level a breakthrough in the nuclear technology field though social support and acceptation.

Nas últimas décadas cresceu o número de pesquisas que defendem os benefícios do uso da História da Ciência na educação científica, entretanto, surgiram também estudos apontando diversas dificuldades para tal fim, inclusive quanto à carência de propostas efetivas para a sala de aula. A partir deste impasse, desenvolvemos uma pesquisa que elabora e analisa o processo de construção de uma abordagem didática da história da radioatividade para o Ensino Médio para ser utilizada por professores de química e de física. Selecionamos aspectos da pesquisa sobre radioatividade, desde seu inicio -- entre as décadas de 1890 e de 1900 -- às suas aplicações, durante o século XX, como tema para a construção de uma proposta didático-metodológica para ensino de física e de química. Além de conceitos científicos, tais episódios permitem discussões metacientíficas, por exemplo, diferenciando a descoberta de um fenômeno natural da construção de explicações sobre ele e a compreensão da ciência enquanto fazer coletivo. Utilizamos como apoio metodológico uma proposta que se propõe a lidar com obstáculos apontados pela literatura, fundamentando a seleção e adaptação de conteúdos históricos na proposição de atividades didáticas, a partir de cada contexto educacional e dos objetivos epistemológicos estabelecidos pelo autor/pesquisador. Oferecemos como resultados desta pesquisa o planejamentos para as aulas, os textos para os alunos (material didático) e para o professor e a análise sobre a construção da proposta, que pode auxiliar outras pesquisas na área. / In recent decades has grown the number of research defending the benefits of using the History of Science in science education, however, there were also studies pointing out the difficulties for that purpose, including proposals for the classroom. From this impasse, we developed a survey that establishes and analyzes the process of building a didactic approach of radioactivity history for the high school for be used by teachers of chemical and physical. We selected aspects of research on radioactivity, since its beginning -- between the 1890s and 1900s -- to their applications, during the twentieth century, as the theme for the construction of a didactic-methodological proposal for physics and chemistry teaching. In addition to scientific concepts such episodes allow metascientific discussions, for example, differentiating the discovery of a natural phenomenon of building explanations about it and understanding of science while making collective. The methodology used, which proposes to deal with obstacles mentioned by the literature, supporting the selection and adaptation of historical contents in proposing educational activities, from every educational context and epistemological objectives set by the author / researcher. We offer as a result of this research the plans for classes, the texts for students (teaching materials) and for the teacher and the analysis on the construction of proposal, that can assist other research in the area.

"Radionuclides in particulate matter associated with outdoor and indoor dusts were analyzed to determine the form and concentration of radioactive isotopes present. These radioactive isotopes, such as Strontium 90, Cesium 137, and Uranium 235, consist of, or are sorbed onto fine particulate matter, (PM). The airborne dispersion of this fine particulate matter results in the facilitated transport of these sorbed or neat radionuclides. Sources of particulate-bound radioactive contaminants include fallout from weapons testing, accumulation of radon daughters, transport of soils containing naturally-occurring radioactive material, remediation of radiologically-contaminated sites, and nuclear material processing. Radiological contaminants in PM, may exist as trace contamination in homogenous collections of particles, but may also exist heterogeneously, as a small number of high-concentration radionuclides among a larger set of uncontaminated particles. A total of 114 samples of indoor and outdoor airborne dusts were collected from a former nuclear weapons production facility near Richland, WA, the Los Alamos National Laboratory, and the Yakama Indian Nation in Wapato, WA. Los Alamos, NM was also the site of the May 2000 Cerro Grande wildfire. The wildfire created very large amounts of airborne particulate matter, including smoke and soot. The area affected by open burning included 43,000 acres. At the national laboratory, greater than 7600 acres were affected, including some areas that were radiologically- contaminated, such as a U-238 ammunition firing area. (LANL, 2007) This introduces a potential source of hot particles in dusts and other archived particulate matter, which may remain in the environment. LANL Airborne radionuclide surveillance has historically found higher uranium levels during windy periods, and saw elevated air uranium levels associated with the Cerro Grande fire. (Ibid, p. 108) Dust samples were sieved to pass a 150 micron screen and analyzed by gamma spectroscopy. Samples with higher activity were analyzed by Scanning Electron Microscopy/Energy Dispersive X-ray analysis, SEM/EDS. The results of gamma spectroscopy and individual particle counts were compared to determine the degree of radioactive heterogeneity in each sample. Radioactive heterogeneity, isotopic distribution, and particle size can be related to the source of the radioactive PM. Radiological contaminants in particulate matter, (PM), may exist as trace contamination in homogenous collections of particles, but may also exist heterogeneously, as a small number of high-concentration radionuclides among a larger set of uncontaminated particles. Residential and source area dusts were collected from locations surrounding, and potentially impacted, by operational and remedial activities at the HNR. The dust samples were analyzed, by multiple means, in order to identify those with radiologically- contaminated particles. Samples with higher activity were further analyzed by Scanning Electron Microscopy/Energy Dispersive X-ray analysis, (SEM/EDS), to determine if the radiological contamination was homogenous or heterogeneous. Two case studies were followed. The method isolated and analyzed lead and bismuth from naturally occurring radioactive material in coal fly ash. The method isolated and fingerprinted thorium, and the rare earths cerium, lanthanum, samarium, neodymium, and gadolinium in sedimentary cerium monazite minerals, nuclear waste processing dusts, and fission waste products in a WWTP effluent channel."