Magnetic deflection techniques have been employed to measure proton angular distributions from some (d,p) and (t,p) reactions. In many cases the distributions exhibit typical stripping patterns and their analysis in terms of plane wave and distorted wave theories of stripping has enabled spin and parity assignments to be made for a number of excited nuclear levels. These theories are briefly outlined in Chapter 1 of this thesis and the experimental procedures are described in Chapter 2. The (d,p) reaction has been studied at an incident energy of 3 MeV with target nuclei B¹⁰, B¹¹, C¹², C¹⁴ and O¹⁶ and an account of this investigation is given in Chapter 3. Although the plane wave theory gives a good account of the angular distributions corresponding to the low-Q transitions (say Q ≤ 2 MeV) it is not a good approximation for the high-Q transitions. This is in accord with Wilkinson's suggestion that distortion effects should be quite small even at low deuteron bombarding energies providing also that the reaction Q-value is low. Agreement with the high-Q ground state distribution for B¹¹ could only be obtained with distorted wave theory if a cut-off radius were used. This may indicate the need for taking into account finite range effects in this theory. The Se⁷⁶(d,p)Se⁷⁷ reaction has been studied at 7.8 MeV bombarding energy and eleven angular distributions corresponding to the ground and ten excited states of Se⁷⁷ have been analysed using distorted wave theory. This investigation is described in Chapter 4. Deuteron and proton elastic scattering measurements have also been made from Se⁷⁶ and Se⁷⁷, respectively. The optical model potentials required to describe the stripping distributions are found to be entirely consistent with those derived from the elastic scattering data. In Chapter 5 an account is given of a systematic study of the (t,p) reaction for target nuclei B¹⁰, B¹¹, C¹², C¹⁴, O¹⁸, Si²⁸, Si²⁹ and Ca⁴⁰. This investigation was carried out at triton energies between 8 and 13 MeV. In the majority of cases the angular distributions are observed to be strongly forward peaked and these have been analysed in terms of Newn's plane wave theory of double stripping. With the exception of the B¹⁰(t,p)B¹² and C¹²(t,p)C¹⁴ reactions the agreement in general is found to be very satisfactory. In addition to the ground state, nine excited states of B¹³ were observed and information on the spins and parities of six of them have been obtained. The excitation energies of only four excited states were previously known. C¹⁶ had not previously been observed and the present investigation has shown this to be stable by 4.25 MeV against neutron emission, in good agreement with the predicitons of Zel'dovich. The ground state was confirmed to be O⁺ and the first excited state at 1.753 MeV excitation is probably 2⁺. The delayed neutron emission for C¹⁶ has also been studied and its measured half-life found to be 0.74 ± 0.03 seconds. Angular distributions were measured for the ground and nine excited states of O¹⁸ and ground and four excited states of O²⁰. Only one state, at 4.45 MeV excitation in O¹⁸, could not be interpreted by a double stripping process. Spin-parity assignments from the reactions Si²⁸(t,p)Si³⁰, Si²⁹(t,p)Si³¹ and Ca⁴⁰(t,p)Ca⁴² are in good agreement with earlier measurements. The Be¹¹ nucleus has been studied using the Be⁹(t,p)Be¹¹ reaction at 6 and 10 MeV triton energies. This investigation is described in Chapter 6. At the higher bombarding energy six energy levels of Be¹¹ were observed and three of these were found to have natural widths in excess of 10 keV. Proton distributions were measured at both energies for the ground and first excited states. Their interpretation in terms of a double-stripping mechanism is complicated by the presence of large backward peaks but the distributions are not inconsistent with the spins of 1/2 ^- and 1/2 ⁺, respectively, predicted by Talmi and Unna. Angular distributions from the C¹²(t,α)B¹¹ reaction at 10 MeV triton energy were also studied in an attempt to obtain information on the spins and parities of some of the states in B¹¹ which are involved in the beta-decay of Be¹¹. In Chapter 7 an account is given of triton elastic scattering measurements made at incident energies 6.4, 6.8 and 7.2 MeV from C¹², O¹⁶, O¹⁸, F¹⁹ and Ca⁴⁰. Only the scattering from F¹⁹ and Ca⁴⁰ can be described by the optical model, although the optical parameters are ambiguous. The scattering distributions from O¹⁶ at all three energies exhibit large backward peaks suggestive of compound resonance scattering. Optical model parameters derived from the triton scattering data have been uesd by Rook and Mitra to analyse the proton distributions from Ca⁴⁰(t,p)Ca⁴², using distorted wave theory. A brief account of the results is given in Appendix C.

Denationalization, to deprive citizens of citizenship, is becoming an international trend – especially in order to fight terrorism. Public opinion is generally positive to these measures. However, few consider the consequences of denationalization. Only when investigating further it becomes clear that citizenship scholars are very concerned about this new trend pointing out that it easily becomes arbitrary, creates statelessness, threatens equality and how it is not an effective measure. This thesis investigates whether Members of Parliament in the UK address these concerns when extending denationalization powers, giving the Secretary of State the most extensive powers to denationalize among all liberal democracies.

A capacidade de ligação de prótons e metais por células vivas da microalga Tetraselmis gracilis (Kylin) butcher foi estudada por titulação potenciométrica e voltametria de redissolução anódica, respectivamente. Dados da titulação alcalimétrica obtidos com uma suspensão de microalga suspensa em NaCl 0,60 mol L-1 a 25,0 ± 0,1 ºC foram tratados por um modelo de distribuição discreta de sítios baseado na linearização das curvas de titulação por funções de Gran modificadas. A concentração total de sítios ionizáveis foi 3,4 x 10-3 mmol g-1, divididos em quatro classes de grupos com pKa 4,4; 5,2; 7,0 e 9,3, cujas abundâncias relativas foram 13, 5,8, 8,2 e 73%, respectivamente. Ligação de Cd(II) e Zn(II) foi estudada em água do mar (pH 8,2) por adições de soluções dos cátion metálicos em soluções simples ou misturas binárias. O cálculo das concentrações dos metais a partir dos dados voltamétricos considerou o agregado célula-metal tendo difusão muito menor do que a do íon livre. Capacidades de adsorção e o logaritmo das constantes de equilíbrio condicionais foram 7,9 ± 0,9 µmol g-1 e 6,9 ± 0,3 L g-1 para Cd(II) e 18,1 ± 0,4 µmol g-1 e 8,8 ± 0,2 L g-1 para Zn(II). Nas titulações com misturas binárias as capacidades de adsorção foram 0,129 ± 0 ,008 e 18,1 ± 0,4 µmol g-1 de Cd(II) e Zn(II), respectivamente, sugerindo que a ligação de Zn(II) inibe a de Cd(II). Entretanto, mesmo na presença de Zn(II) a superfície de alga possui sítios minoritários que se ligam a Cd(II) (log Kads = 7,7 ± 0,2), o que pode causar a bioacumulação desse íon metálico tóxico. / Proton and metal binding capacities of living cells of the microalgae Tetraselmis gracilis (Kylin) butcher were determined by potentiometric titration and anodic stripping voltammetry, respectively. Data of alkalimetric titration of the microalgae suspension obtained in 0.60 mol L-1 NaCl at 25.0 ± 0.1ºC was treated by a discrete site distribution model based on the linearization of the titration curve by modified Gran functions. A total of 3.4 x 10-3 mmol g-1 ionizable sites were determined, divided in four classes of groups with pKa 4.4, 5.2, 7.0 and 9.3, whose relative abundances were 13, 5.8, 8.2 and 73%, respectively. Binding of Cd(II) and Zn(II) was studied in seawater (pH 8.2) by additions of either single metallic species or binary mixtures. Computation of free metal concentrations from the voltammetric data considered the cell-metal aggregates with diffusion coefficient significantly lower than that of free metal ions. Adsorption capacities and the logarithm of the conditional equilibrium constants were 7.9 ± 0.9 µmol g-1 and 6.9 ± 0.3 L g-1 for Cd(II) and 18.1 ± 0.4 µmol g-1 and 8.8 ± 0.2 L g-1 for Zn(II). For titrations with binary mixtures of Cd(II) and Zn(II ) the adsorption capacity of Cd(II) were 0.129 ± 0.008 µmol g-1 and 18.1 ± 0.4 µmol g-1, respectively. The results suggest that binding of Zn(II) inhibits that of Cd(II). However, even in the presence of Zn(II), the alga surface has some minor sites that can bind Cd(II) (log Kads = 7.7 ± 0.2), a process that can lead to bioaccumulation of this toxic metal ion.

Este trabalho apresenta o desenvolvimento e a aplicação de um método alternativo para determinação de manganês em amostras de cimento e clínquer por voltametria de redissolução catódica por onda quadrada empregando eletrodos de ouro. Após estudos exploratórios acerca do comportamento eletroquímico do manganês no eletrólito suporte H3BO3 0,20 mol L-1 / KCl 0,10 mol L-1 com pH 6,5 e a otimização dos parâmetros operacionais para a voltametria de onda quadrada, foram obtidos excelentes resultados na determinação de manganês nas amostras analisadas. Destacam-se a ótima linearidade, verificada em duas faixas distintas de concentração, e os baixos limites de detecção e quantificação obtidos (3,1 x 10-8 mol L-1 e 9,8 x 10-8 mol L-1, respectivamente), além da concordância entre os resultados obtidos pela técnica eletroanalítica quando comparados aos resultados fornecidos pela espectrometria de absorção atômica de chama (FAAS). Para o tratamento das amostras foi avaliada a eficiência da extração ácida assistida por ultrassom. Foram avaliados ácidos minerais individualmente (HCl, H2SO4 e HClO4 em diferentes concentrações), em mistura ou ainda associados a H2O2. Os melhores resultados foram obtidos utilizando uma solução de HCl 3 mol L-1, que extraiu quantitativamente o manganês nas amostras analisadas. Os resultados obtidos foram concordantes com a metodologia padrão utilizada para a abertura da amostra e posterior análise por espectrometria de absorção atômica de chama, que emprega o aquecimento em chapa e a mesma solução extratora. / This work describes the development and application of a new alternative method for determination of manganese in cement and clinker samples by square wave cathodic stripping voltammetry using gold electrodes. After exploratory studies on the electrochemical behavior of manganese in H3BO3 0.20 mol L-1 / KCl 0.10 mol L-1 supporting electrolyte at pH 6.5 and the optimization of operating parameters for the square wave voltammetry, excellent results were obtained for determination of manganese in the samples analyzed. Most notable are the excellent linearity, verified in two distinct concentration bands and the low limits of detection and quantification obtained (3,1 x 10-8 mol L-1 e 9,8 x 10-8 mol L-1, respectively), in addiction to the concordance between the obtained results by the electroanalytical technique when compared to the provided by the flame atomic absorption spectrometry. For samples treatment were tested the efficiency of the ultrasound-assisted extraction. Were evaluated individually mineral acids (HCl, H2SO4 and HClO4 at different concentrations) in a mixture or associated with H2O2. the best results were obtained using a 3 mol L-1 HCl solution, which extracted manganese quantitatively from the analysed samples, in comparison to the standard method for extraction, targeting a later atomic absorption flame spectrometry analysis, which uses the plate heating and the same extracting solution. The obtained results for the analysed samples agrees with the cement and clinker samples of the used literature

Nos dias de hoje um grande número de pesticidas é utilizado em colheitas, agricultura, transporte de sementes, entre outros. Esses pesticidas são moléculas orgânicas que apresentam em sua estrutura grupos funcionais capazes de formar ligações com íons metálicos, que de forma natural ou por intervenção humana, são encontradas no solo. Estas espécies entram em contato no meio ambiente, e assim, interagem formando ligações, dando forma aos chamados compostos de coordenação, ou complexos. A formação destes complexos pode alterar significativamente as propriedades dos pesticidas e dos íons metálicos, podendo acentuar seu caráter tóxico, sua persistência e degradação. Neste trabalho foram escolhidos dois pesticidas que são bons exemplos deste tipo de molécula. O fungicida Thiram, que apresenta em sua estrutura átomos de enxofre, e assim interage com uma gama de íons metálicos; e o herbicida picloram, que é um derivado piridínico, o qual apresenta um átomo de nitrogênio com pares de elétrons livres e capazes de formar ligações, e um grupamento ácido na posição dois do anel também capaz de interagir com íons metálicos. Com o intuito de se entender melhor como ocorre estas interações, realizou-se este trabalho onde observou-se a complexação dos pesticidas thiram e picloram com quatro íons metálicos previamente selecionados, zinco, cobre, cádmio e chumbo. Dessa forma, deu-se início a um estudo de complexação utilizando o método de Voltametria de Redissolução Anódica em modo de Pulso Diferencial, a fim de se avaliar a ocorrência desta complexação. Para isso, contamos com duas ferramentas muito utilizadas para a avaliação da capacidade complexante de amostras, os métodos de linearização de Scatchard e Langmuir. Com a técnica utilizada foram levantadas curvas de titulação de amostras contento os pesticidas, e a partir dos dados obtidos aplicou-se os cálculos de Langmuir e Scatchard para se obter dois parâmetros importantes, a constante de estabilidade condicional do complexo formado, K\', e a concentração de ligante que participa da reação de complexação em solução, [L]T. Os dados obtidos com ambos pesticidas foram satisfatórios, indicando a ocorrência de complexos. Porém, observou-se que essa interação é maior entre o fungicida thiram e os respectivos metais do que com o herbicida picloram. As constantes de estabilidade condicional para o fungicida thiram se encontram com Log de K\' entre 6 e 7, enquanto as mesmas para os complexos formados entre o herbicida picloram e os íons metálicos se encontram entre 5 e 6. Para se confirmar as medidas de voltametria de redissolução anódica, foram realizadas medidas de espectroscopia na região do ultravioleta visível, bem como medidas de voltametria cíclica e de pulso diferencial. / Nowadays, numerous pesticides are used in crops, agriculture, transport of seeds, among others. These pesticides are organic molecules that present functional groups in their structure which are capable of forming connections with metallic ions, which, whether naturally or by human intervention, are found in the soil. These species enter in contact in the environment, and thus, they interact forming connections, giving form to the so called compound of coordination, or complex. The formation of these complexes can alter significantly the properties of both the pesticides and the metallic ions, being able to enhance toxic character, persistence and degradation. In this work, two pesticides were chosen for being good examples of this type of molecule. The fungicide Thiram, which presents atoms of sulfur in its structure, and thus interact with a range of metallic ions; and the herbicide picloram, a derived pyridinic, which presents a nitrogen atom with pairs of free electrons and capable of forming binding, and an acid group in the position two of the ring, also capable of interacting with metallic ions. In order to better understand how these interactions occur, this work focused where the complexation of pesticides thiram and picloram was observed with four metallic ions previously selected, zinc, copper, cadmium and lead. Hence, a study of complexation was started using the method of Differential Pulse Anodic Stripping Voltammetry, in order to evaluate the occurrence of the complexation. For that, we counted on two tools very frequently used for the viii evaluation of the metal-binding capacity of samples, namely, the linearization methods of Scatchard and Langmuir. Titration curves of the samples containing the pesticide were obtained using the technique, and starting from the data, the calculations of Langmuir and Scatchard were applied in order to obtain two important parameters, stability conditional constant of the formed compound, K\', as well as the ligand concentration that participates in the reaction complexation in solution, [L]T. The data obtained with both pesticides were satisfactory, indicating the occurrence of complexes. However, it was observed that the interaction is larger between the fungicide thiram and the respective metals than with the herbicide picloram. The constants of conditional stability for the fungicide thiram are with LogK\' between 6 and 7, while the same ones for the compounds formed between the herbicide picloram and the metallic íons are between 5 and 6. To confirm the measures of anodic stripping voltammetry, spectroscopy measures were carried out in the area of the visible ultraviolet, as well as measures of cyclic voltammetry and of differential pulse.

It has been shown that prolonged systemic presence of a drug can cause a build up of that drug in the skin. This drug ‘reservoir’, if properly understood, could provide useful and important information about the recent drug-taking history of a patient. In this thesis we create three mathematical models which combine to explore the potential for a drug reservoir to form in the skin and be collected as a method of monitoring compliance. The first model is used to characterise timedependent drug concentrations in plasma and tissue following a customisable drug regimen. Outputs from this model provide boundary conditions for the second, spatio-temporal model of drug build-up and concentration profile in the skin. This then provides initial conditions for the final model which predicts the extraction. These models are then used to identify the scenarios which have the greatest potential for successfully monitoring patient compliance via the skin. We focus in particular on drugs that are highly bound as this will restrict their potential to move freely into the skin but which are lipophilic so that, in the unbound form, they would demonstrate an affinity to the outer layers of the skin (which are built around a lipid matrix). We highlight how this study might be used to inform future experimental design and data collection in order to provide relevant parameter estimates for reservoir formation and its potential to contribute to enhanced drug monitoring techniques.

Made available in DSpace on 2014-06-12T17:37:01Z (GMT). No. of bitstreams: 2 arquivo2411_1.pdf: 5312881 bytes, checksum: c64ce8cf019e06d5c86303daf17de7b4 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2011 / Faculdade de Amparo à Ciência e Tecnologia do Estado de Pernambuco / O tratamento de lixiviado proveniente de aterros de resíduos sólidos urbanos, tornou-se um grande desafio para a comunidade científica uma vez que nem sempre um sistema de tratamento adotado para uma determinada região torna-se adequado para outra, em função da grande variabilidade da composição do lixiviado. Os sistemas de tratamento a serem adotados devem levar em consideração as particularidades da região a fim de tornar o sistema economicamente viável. De um modo geral, a concepção adotada como escopo desta pesquisa consistiu em um sistema de baixo custo, fácil implantação, simples operação e com boa remoção de poluentes. Durante as análises realizadas em escala piloto, adotou-se uma vazão em fluxo contínuo de 0,1 L/s , que equivale a cerca de 10% da vazão real do Aterro da Muribeca, onde as características físico-químicas deste lixiviado serviram de base para o dimensionamento da estação piloto. A estação piloto projetada é composta por três etapas: precipitação química, stripping da amônia e barreira reativa com carvão ativado. Os resultados deste estudo apresentaram um desempenho médio de remoção de DBO (>80%) e DQO (>85%) superior a eficiência de 60% de remoção exigida pela legislação estadual mineira para tratamento de lixiviado, tornando-se suficiente ao lançamento em rios classe 3. A concentração de amônia, para todos os ensaios realizados, encontrou-se acima do permitido pela legislação federal, em função do baixo tempo de detenção adotado para a etapa do stripping da amônia. Quanto à cor do lixiviado, de um modo geral, não conferiu mudança de coloração acentuada ao corpo receptor após seu lançamento, estando em concordância com a legislação federal. Estimando-se o custo final do tratamento em escala real, obteve-se um valor médio abaixo do praticado no Brasil

The use of constructed wetlands and wet detention basins has proven to be highly effective in removing pollutants from industrial discharges and stormwater runoff throughout the world. This is attributed to design of the key treatment components in a constructed wetland, catchment source characteristics and climatic conditions. A disproportionate amount of research and monitoring effort has gone into constructed wetlands due to their cost effectiveness and ability to optimize multiple benefits. In Western Australia, several wetland monitoring studies on the role of constructed wetlands especially in Swan-Canning estuary have been done, but often do not address their design efficiencies in stormwater treatment. Two wetlands (Liege St and Tom Bateman wetland) constructed for nutrient stripping proximal to the Swan-Canning estuary have been monitored for two years. Liege St wetland was constructed to reduce the nutrients reaching the Canning River directly and improve the amenity value of the area. Similarly, Tom Bateman wetland was constructed to reduce nutrients of the Banister Creek catchment draining into the Canning River as well as for stormwater management and habitat use. Physicochemical and biological indicators were used to assess the nutrient stripping efficiency of the wetlands. In some cases, data from previous studies were used to determine the health and viability of the selected wetland sites. The limnological indicators used included; dissolved oxygen, pH, water temperature, electrical conductivity and nutrient levels. The biological included; bacteria, nutrients and chlorophyll in periphyton, macroinvertebrates and diatoms. Differences in the community structure of periphyton, macroinvertebrates and water quality were found from the inlet to the outlet in both Liege St and Tom Bateman wetlands. / Despite the poor water quality, Liege St wetland exhibited significant nutrient removal efficiencies for TP while Tom Bateman wetland had very high removal efficiency for TN. The TP removal in Liege St wetland was attributed to the design of key treatment components which included a gross pollutant trap, concrete lined sedimentation pond, vegetated sumplands, weirs and clay lining for the wetland bed. In contrast, Tom Bateman wetland lacked the above key treatment components. Additionally, the wetland experienced short-circuiting especially during high flow periods. The high TN removal in Tom Bateman wetland was attributed to assimilation by plants and micro-organisms especially by the dense growth of Potamogeton crispus observed on the wetland floor and the non- biological transformation processes such as volatilisation, sorption and sedimentation. The poor water quality of the inflow in both wetlands was attributed to catchment characteristics which were not fully investigated in this study. In an attempt to improve the nutrient stripping function of Liege St and Tom Bateman wetland, changes to the wetland design and routine maintenance were suggested for Tom Bateman and Liege St wetland respectively. Also the use of the Swan-Canning Cleanup Programe (SCCP) water quality targets as opposed to the ANZECC trigger values in water quality assessments in constructed wetlands in the Swan-Canning estuary is suggested among others.

This thesis describes the development of new adsorptive cathodic stripping voltammetric methods for reliable determination of some trace metals in biological and environmental materials on a glassy carbon mercury film electrode. In particular, the development of these methods involved selection of a suitable complexing agent for the respective metal ion studied, characterization of the electrode processes, investigation of factors affecting the voltammetric response such as concentration and pH of supporting electrolyte, concentration of complexing agent, accumulation potential, accumulation time and electrode rotation rate. Also, organic and inorganic interferences, linear concentration range, and detection limits were carefully considered. Furthermore, the analytical application of the method was demonstrated for each metal in biological and/or environmental materials, after optimization of the sample decomposition procedure. Some conclusions : the results obtained by the AdCSV method for the determination of tin in juices agreed reasonably with those obtained by atomic absorption method; the use of the adsorptive voltammetric technique after dry-ashing and UV treatment of the samples was successfully demonstrated for the determination of vanadium in standard reference materials such as urban particulate matter, peach leaves, apple leaves and bovine liver; and, the use of the adsorptive stripping voltammetric technique, after decomposition of samples by dry-ashing and UV treatment, was successfully demonstrated for the determination of molybdenum in peach leaves, apple leaves and bovine liver samples. / Doctor of Philosophy (PhD)

Detection of chromium and vanadium is of interest for biomedical and environmental applications. The two metals have narrow limits between being essential and toxic for humans. Ultra-sensitive techniques have been studied to measure Cr and V at low concentrations found in human blood and environmental samples. Bismuth film and mercury-alloy electrodes have been developed as alternatives to traditional Hg-based electrodes for Cr and V detection. While catalytic adsorptive stripping voltammetry (CAdSV) has been used to detect Cr and V, little is known about the process. The mechanisms of CAdSV have been probed to provide a better understanding of its exceptional sensitivity and selectivity. Near-real time monitoring of plume gas constituents is desired as a diagnostic tool for combustion efficiency, ensuring safe testing conditions and observing releases of green house gasses. Ground testing rockets is a crucial preliminary step that ensures their performance during critical space missions. Optical sol-gel sensors for carbon dioxide have been developed for remote sensing applications. They are inexpensive and are compatible with the harsh environments encountered during rocket plume tests. The sensors are a viable approach to compliment current infrared (IR) measurements for real-time carbon dioxide detection. Additional work on kerosene and isopropyl alcohol sensing has been explored for incorporation into a multi-analyte sensing platform.