Este trabalho foi desenvolvido objetivando a determinação e a avaliação dos perfis temporais da concentração de alguns elementos químicos potencialmente tóxicos presentes no material particulado em suspensão (MPS) no interior de uma pequena indústria de fundição de metais bronze, ferro e alumínio que, em concentrações elevadas, podem acarretar sérios riscos à saúde do trabalhador. Para isso foi utilizado um amostrador temporal de MPS, que coleta amostras de aerossóis em intervalo de tempo pré-programados, separando-os por tamanho: (a) fração fina ou respirável (partículas com diâmetro aerodinâmico menor que 2,5 m, MP2,5) e (b) fração grossa ou inalável (entre 2,5 a 10 m, MP10-2,5), durante todo o período do processo de fundição (da fusão à moldagem). As amostras coletadas, na forma de faixas (strips) sobre um filtro (fração fina) e sobre um impactador (fração grossa), foram analisadas pela técnica de fluorescência de raios X por dispersão de energia (EDXRF), utilizando na excitação um tubo de raios X com alvo de Mo e e na detecção dos raios X característicos um detector semicondutor de Si(Li) acoplado a um analisador de pulsos multicanal, interpretando-se posteriormente os espectros de raios X obtidos pelo aplicativo AXIL. Para algumas amostras também foi feita uma análise com microscópio eletrônico de varredura (SEM/EDS) para se conhecer a morfologia dos particulados. Deste modo foi possível determinar a concentração de elementos químicos potencialmente tóxicos presentes em um ambiente de uma pequena indústria de fundição de metais, mostrando que o momento mais crítico dessa atividade foi o da moldagem e também determinar a forma do MPS. Na fundição do bronze e ferro, as concentrações dos elementos Cr, Mn, Ni e Pb, principalmente na fração fina no momento de moldagem, mostraram-se muito superior aos limites recomendados pelas agências brasileira e norte-americana. Apesar de não haver limites recomendados para o elemento Zn, foi verificada uma alta concentração principalmente na concentração na fração fina, o mesmo sucedendo para o Cu. Com respeito a fundição de alumínio, foi observado altas concentrações principalmente de Zn e Cu, somente na fração fina, não ocorrendo na fração grossa. Pelos resultados obtidos pode-se concluir que os trabalhadores estão sujeitos a condições insalubres de trabalho nesse tipo de ambiente, aconselhando-se o uso permanente de equipamentos adequados de proteção visando de preferência a fração fina, assim como um monitoramento constante desses elementos químicos durante todas as etapas do processo de fundição, principalmente na de moldagem / The aim of this work was to evaluate the chemical concentration of some potentially toxic inorganic chemical elements and the time profiles in fine (PM2.5, particles up to 2.5 m) and coarse (PM2.5-10, particles from 2.5 to 10 m) suspended particulate matter (SPM) inside a small foundry plant - bronze, iron and aluminium -, in which at high concentrations turns a healthy concern. For these purpose, a rotating streaker airparticulate sampler for sampling during all day foundry activity was utilized. Fine SPM was collected on a filter and coarse SPM in turn by an impactor. The collected samples were analyzed by energy dispersive X-ray fluorescence (EDXRF) technique employing a Mo target tube in the excitation, and the detection was carried out through Si(Li) semiconductor detector coupled to multichannel analyser, deconvolutting the X-ray spectra with AXIL software help. It was also carried out particulated morphological analysis by scanning electron microscopy with energy dispersive X-ray spectrometer coupled (SEM/EDS). In this manner, the inorganic chemicals content were determined in the small foundry allowing concluding that the moulding step is the critical one taking into account the amount of pollutant released. During bronze and iron melting, the Cr, Mn, Ni and Pb contents in SPM were higher than allowed values by Brazilian and United States legislations. It was also verified a high Zn and Cu content, mainly in the fine suspended particulate matter, although these elements are not contemplated by national nor international laws. Thus, due to this unhealthy environmental working conditions inside the small foundry plant,a proper individual protection equipment is mandatory mainly for fine suspended particulate matter, and a constant air pollutant monitoring in foundry plants is demanded, mainly during the moulding step

Microalgae, photosynthetic microorganisms, are rich in lipids, polyunsaturated fatty acids, carbohydrates, proteins, vitamins, as well as carotenoids, which are antioxidants that may protect human body from various diseases including obesity, cardiovascular disease, vision-related diseases such as macular degeneration and certain types of cancer. These natural pigments have applications in the pharmaceutical (nutraceutical), food (coloring, functional food, and supplements), and cosmetics industries (e.g. sunscreen), as well as in aquaculture (animal feed). The Dunaliella salina microalga can synthesize 10% of dry weight in &#946;-carotene (orange pigment, pro-vitamin A activity) under high light intensity and nitrogen and phosphorus limitation, among other stress conditions. The first chapter of this thesis presents a review focused on microalgae carotenoids: culture systems, mode of operation, and applications. In this bibliographic survey, the advantages of microalgae cultivation in relation to traditional sources (higher plants) were discussed, as well as a discussion of the main cultivation systems and their importance in cell growth. This review presented a critical analysis of the different operational regimes like batch, fed-batch, semi-continuous and continuous. Relevant information on the most important world producers of microalgae carotenoids were presented. Chapter II presents the development of a modified method of dispersive liquid-liquid microextraction (DLLME) for rapid extraction of &#946;-carotene from Dunaliella salina cultivated in tubular photobioreactor, with subsequent development of a rapid chromatographic screening method using a C4 column for separation of geometric isomer of &#946;-carotene. The use of benzene as extraction solvent and water with 50% acetone as dispersant provided the best condition for the extraction of this carotenoid. In HPLC (High Performance Liquid Chromatography), employing mobile phase composed of methanol and water (95:5, v/v), it was possible to detect/quantify &#946;-carotene at 14 min (retention time). Besides the short analysis time (<20 min), by the miniaturized extraction (< 10 mL organic waste) this method abide by green chemistry analytical principles. It is known that nitrogen, phosphorus, as well as carbon and vitamins are vital elements for the growth of microalgae, also determining the biochemical composition of biomass. In this sense, Chapter III presents the study of the influence of different amounts of sodium nitrate (1N = 75 mg L-1; 1.5N = 112.5 mg L-1, and 3N = 225 mg L-1) and phosphate monobasic dehydrate (1P = 5.65 mg L-1, 1.5P = 8.47 mg L-1, and 3P = 16.95 mg L-1) in seawater-based f/2 medium on the growth of Dunaliella salina and &#946;-carotene biosynthesis, by continuous process with different replenishment proportions (R = 20% and 80%). Best results of cell productivity were obtained by semicontinuous process (mean values of Px up to 6.7 x 104 cells mL-1 d-1 with medium 1N:1P; R =20%) in comparison with batch process cultivation. Maximum cell density (Xm) obtained in this work was not dependent of R, but the best results were obtained when using medium 1.5N:1.5P (mean values up to 5.6 x 105 cells mL-1 with R =80%) instead of 1N:1P. The content of &#946;-carotene in the cells, in general, was higher in cells grown in medium 1N:1P (mean yield values up to 57.5 mg g-1 with R =80%) in comparison with medium 1.5N:1.5P. The cultivation of D. salina with media 3N:3P led to a long lag phase, followed by decrease in cell density and cell lysis. The use of a tubular photobioreactor contributed to successfully cultivate this microalga without contamination by protozoa. The cultivation of Dunaliella salina in tubular photobioreactor with the use of 12:12 photoperiod was appropriate, as well as to induce carotenogenesis, in the second stage, by increasing the light intensity and absence of pH control / As microalgas, micro-organismos fotossintetizantes, são ricas em lipídios, ácidos graxos poli-insaturados, carboidratos, proteínas, vitaminas, além de carotenoides que são antioxidantes com potencial de proteger o organismo humano de várias doenças incluindo a obesidade, doenças cardiovasculares, doenças relacionadas à visão como a degeneração macular e certos tipos de câncer, entre outras. Esses pigmentos naturais têm aplicações em indústrias farmacêuticas (nutracêuticos), alimentícias (colorantes, alimentos funcionais e suplementos) e de cosméticos (exemplo: filtro solar) e na aquacultura (ração animal). A microalga Dunaliella salina é capaz de sintetizar, sob alta intensidade luminosa e limitação de nutrientes como fontes de fósforo e nitrogênio, dentre outras condições de estresse, 10 % do peso seco em &#946;-caroteno (pigmento laranja com atividade pró-vitamina A). Assim, neste trabalho, numa primeira etapa, foi feita uma revisão da literatura abordando a produção de carotenoides por microalgas, bem como sua aplicação. Nesse levantamento bibliográfico abordou-se, dentre outros assuntos, as vantagens do cultivo de microalgas em relação as fontes tradicionais (plantas superiores), assim como uma discussão dos diferentes sistemas de cultivos e sua importância no crescimento celular. Esse review apresentou uma análise crítica dos principais regimes operacionais como batch, fed-batch, semicontínuo e contínuo. Apresentou-se também informações relevantes sobre os mais importantes produtores mundiais de carotenoides de microalgas. Numa segunda etapa, foi desenvolvido um método modificado de microextração líquido-líquido dispersivo modificado (DLLME) para a rápida extração de &#946;-caroteno de Dunaliella salina cultivada em fotobiorreatores tubulares, com subsequente desenvolvimento de método cromatográfico em uma coluna C4 para a separação do isômero geométrico de &#946;-caroteno. A extração ótima de &#946;-caroteno foi obtida com benzeno como solvente extrator e água com 50% de acetona como dispersante. Empregando uma fase móvel composta por metanol e água (95:5, v/v) em HPLC, foi possível a detecção/quantificação de &#946;-caroteno com 14 minutos de tempo de retenção. Além dos tempos curtos de análises (<20 min), pela extração em volume reduzido (< 10 mL resíduos orgânicos) este método obedece aos princípios da química verde. Sabe-se que nitrogênio, fósforo, assim como carbono e vitaminas são elementos vitais para o crescimento das microalgas e também exercem influência na composição bioquímica da biomassa. Assim, na terceira etapa deste trabalho, estudou-se a influência das quantidades de nitrato de sódio (75 mg L-1, denominado 1N; 112,5 mg L-1, denominado 1,5N; 225 mg L-1, denominado 3N) e de fosfato monobásico dihidratado (5,65 mg L-1, denominado 1P; 8,47 mg L-1, denominado 1,5P; 16,95 mg L-1, denominado 3P) em meio f/2, que tem como base a água do mar, no crescimento e na síntese de &#946;-caroteno da Dunaliella salina por processo semicontínuo, com uso de frações de corte (R) de 20% e 80%. Foram obtidas produtividades celulares mais elevadas em processos semicontínuos do que em processo descontínuo, com produtividades médias de até 6,7 x 104 células mL-1 d-1 (meio 1N:1P; R =20%). A máxima concentração celular (Xm) obtida neste trabalho não foi dependente de R. Os melhores resultados de Xm foram obtidos quando se usou meio 1,5N:1,5P em vez de meio, com 1N:1P, com valores médios de até 5,6 x 105 células m L-1 (R =80%). O conteúdo de &#946;-caroteno nas células, de maneira geral, foi maior nas células cultivadas em meio 1N:1P do que no meio 1,5N:1,5P, com valores até 57,5 mg g-1 (R =80%). O cultivo de D. salina com o meio 3N:3P levou a uma longa fase lag, seguida por uma diminuição na concentração celular e sua lise. O cultivo de células em um fotobiorreator tubular contribuiu para um crescimento celular sem contaminação por protozoários. O cultivo de Dunaliella salina em fotobiorreator tubular com o uso de fotoperíodo 12:12 foi apropriado, assim como induzir a carotenogênese, no segundo estágio, por meio do aumento da intensidade luminosa e ausência de controle de pH.

O Brasil produz cerca de 2,2 milhões de metros cúbicos de madeira preservada para atender à demanda anual nos setores de transporte ferroviário, elétrico, rural e de construção civil. As espécies de madeiras mais usados são do eucalipto (Eucalyptus sp.) e pinus (Pinus sp.). A madeira preservada, utilizada para postes, dormentes, mourões e nas construções em madeira, deve estar em conformidade com as especificações exigidas pelas normas brasileiras quanto ao seu tratamento preservativo. No Brasil, os preservativos de madeira mais utilizados e regulamentados são CCA (arseniato de cobre cromatado) e o CCB (sal de cobre cromo e boro). As técnicas analíticas como espectrometria de absorção atómica de chama (FAAS) e espectrometria de emissão de plasma acoplado (ICPOES) e espectrometria de fluorescência de raios x (XRFS) são utilizadas para a avaliação desses processos. Neste trabalho, as amostras de madeira foram obtidas de árvores de eucalipto (Eucalyptus sp.), provenientes de áreas de plantação do estado de Minas Gerais, Brasil. Amostras de madeira de eucalipto foram submetidas a diferentes concentrações de solução de CCA, sob pressão, atingindo retenções de 3,9; 6,7; 9,1; 12,4 e 14,0 kg de CCA por m-³ de alburno. A partir dos blocos tratados foram obtidos amostras em forma de cilindros e serragem. A determinação de cobre, cromo e arsênio foi realizada pela espectrometria de fluorescência de raios X de energia dispersiva (EDXRF), espectrometria de fluorescência de raios X portátil (PXRF), FAAS e IAAN. Neste trabalho, foram avaliados métodos de análise, sensibilidade e precisão, exatidão das técnicas analíticas relacionadas. / Brazil produces around 2.2 millions of cubic meters of treated wood to meet the annual demand of railway, electric, rural and construction sectors. The most used wood species are eucalyptus (Eucalyptus ssp.) and pine (Pinus ssp.).The treated woods used for poles, sleepers, fence posts and plywoods should be according to Brazilian norms requirements. The most usual wood preservative products used in Brazil are CCA (chromated copper arsenate) and CCB (copper chromium and boron salt). The analytical methods, such as flame atomic absorption spectrometry (FAAS), plasma inductively coupled optical emission spectrometry (ICPOES) and X-ray fluorescence spectrometry (XRFS) have been used for the analytical control of those treatment processes. In this work, the eucalyptus trees (Eucalyptus ssp) samples was obtained from Minas Gerais State, Brazil, cut plantation areas. Under pressure, eucalyptus wood samples were submitted to different concentration of CCA solution reaching 3.9, 6.7, 9.1, 12.4 and 14.0 kg of CCA by m-³ sapwood retentions. Samples in cylinders and sawdust forms were obtained from treated wood samples. Copper, chromium and arsenic determination was performed using the energy dispersive X-ray fluorescence spectrometry (EDXRFS), portable X-ray fluorescence spectrometry (PXRFS), flame atomic absorption spectrometry (FAAS) and instrumental neutron activation analysis. In this work, the method of analysis, sensitivity, precision and accuracy performances of the related techniques were outlined.

Environmentally-assisted cracking (EAC) phenomena affect the in-service behaviour of austenitic stainless steels in nuclear power plants. EAC includes such degradation phenomena as Stress Corrosion Cracking (SCC) and Corrosion Fatigue (CF). Factors affecting EAC include the material type, microstructure, environment, and stress. This is an important degradation issue for both current and Gen III+ light water reactors, particularly as nuclear power plant lifetimes are extended ( > 60 years). Thus, it is important to understand the behaviour of the alloys used in light water reactors, and phenomena such as SCC to avoid failures. Although there is no agreement on the mechanism(s) of SCC, the importance of localized electrochemical reactions at the material surface is widely recognised. Considerable research has been performed on SCC and CF crack growth, but the initiation phenomena are not fully understood. In this project, novel in situ analytical TEM techniques have been developed and applied to explore localised reactions in Type 304 austenitic stainless steel. In situ transmission electron microscopy has become an increasingly important and dynamic research area in materials science with the advent of unique microscope platforms and a range of specialized in situ specimen holders. In metals research, the ability to image and perform X-ray energy dispersive spectroscopy (XED) analyses of metals in liquids are particularly important for detailed study of the metal-environment interactions with specific microstructural features. To further facilitate such studies a special hybrid specimen preparation technique involving electropolishing and FIB extraction has been developed in this thesis to enable metal specimens to be examined in the liquid cell TEM specimen holder using both distilled H2O and H2SO4 solutions. Furthermore, a novel electrode configuration has been designed to permit the localized electrochemical measurement of electron-transparent specimens in the TEM. These novel approaches have been benchmarked by extensive ex situ experiments, including both conventional electrochemical measurements and microcell measurements. The results are discussed in terms of validation of in situ test data as well as the role of the electron beam in the experiments. In situ liquid cell TEM experiments have also explored the localized dissolution of MnS inclusions in H2O, and correlated the behaviour with ex situ experiments. Based on the research performed in this thesis, in situ liquid cell and in situ electrochemical cell experiments can be used to study nanoscale reactions pertaining to corrosion and localized dissolution leading to "precursor" events for subsequent EAC phenomena.

O Brasil produz cerca de 2,2 milhões de metros cúbicos de madeira preservada para atender à demanda anual nos setores de transporte ferroviário, elétrico, rural e de construção civil. As espécies de madeiras mais usados são do eucalipto (Eucalyptus sp.) e pinus (Pinus sp.). A madeira preservada, utilizada para postes, dormentes, mourões e nas construções em madeira, deve estar em conformidade com as especificações exigidas pelas normas brasileiras quanto ao seu tratamento preservativo. No Brasil, os preservativos de madeira mais utilizados e regulamentados são CCA (arseniato de cobre cromatado) e o CCB (sal de cobre cromo e boro). As técnicas analíticas como espectrometria de absorção atómica de chama (FAAS) e espectrometria de emissão de plasma acoplado (ICPOES) e espectrometria de fluorescência de raios x (XRFS) são utilizadas para a avaliação desses processos. Neste trabalho, as amostras de madeira foram obtidas de árvores de eucalipto (Eucalyptus sp.), provenientes de áreas de plantação do estado de Minas Gerais, Brasil. Amostras de madeira de eucalipto foram submetidas a diferentes concentrações de solução de CCA, sob pressão, atingindo retenções de 3,9; 6,7; 9,1; 12,4 e 14,0 kg de CCA por m-³ de alburno. A partir dos blocos tratados foram obtidos amostras em forma de cilindros e serragem. A determinação de cobre, cromo e arsênio foi realizada pela espectrometria de fluorescência de raios X de energia dispersiva (EDXRF), espectrometria de fluorescência de raios X portátil (PXRF), FAAS e IAAN. Neste trabalho, foram avaliados métodos de análise, sensibilidade e precisão, exatidão das técnicas analíticas relacionadas. / Brazil produces around 2.2 millions of cubic meters of treated wood to meet the annual demand of railway, electric, rural and construction sectors. The most used wood species are eucalyptus (Eucalyptus ssp.) and pine (Pinus ssp.).The treated woods used for poles, sleepers, fence posts and plywoods should be according to Brazilian norms requirements. The most usual wood preservative products used in Brazil are CCA (chromated copper arsenate) and CCB (copper chromium and boron salt). The analytical methods, such as flame atomic absorption spectrometry (FAAS), plasma inductively coupled optical emission spectrometry (ICPOES) and X-ray fluorescence spectrometry (XRFS) have been used for the analytical control of those treatment processes. In this work, the eucalyptus trees (Eucalyptus ssp) samples was obtained from Minas Gerais State, Brazil, cut plantation areas. Under pressure, eucalyptus wood samples were submitted to different concentration of CCA solution reaching 3.9, 6.7, 9.1, 12.4 and 14.0 kg of CCA by m-³ sapwood retentions. Samples in cylinders and sawdust forms were obtained from treated wood samples. Copper, chromium and arsenic determination was performed using the energy dispersive X-ray fluorescence spectrometry (EDXRFS), portable X-ray fluorescence spectrometry (PXRFS), flame atomic absorption spectrometry (FAAS) and instrumental neutron activation analysis. In this work, the method of analysis, sensitivity, precision and accuracy performances of the related techniques were outlined.

A lamotrigina (LTG) é um fármaco pertencente à classe das feniltriazinas utilizado no tratamento de crises epilépticas generalizadas e focais e no tratamento adjunto da epilepsia refratária. Devido à alta variabilidade interindividual, às interações medicamentosas e aos efeitos adversos apresentados durante a administração da LTG, a monitorização terapêutica nos pacientes que fazem uso deste fármaco é necessária para ajuste de dose individual e evitar os efeitos adversos. Assim, o objetivo deste trabalho foi a avaliação de duas técnicas de microextração: a microextração em fase líquida com fibras ocas (HF-LPME) e a microextração líquido-líquido dispersiva (DLLME) para análise da lamotrigina em amostras de plasma de pacientes epilépticos. Primeiramente foram definidas as condições eletroforéticas: foi utilizado um capilar de sílica fundida de 75 ?m de diâmetro interno e 50 cm de comprimento efetivo. O eletrólito de corrida (BGE) foi composto por ácido 2-morfolinoetanosulfônico (MES), na concentração de 130 mmol L-1 e pH 5,0. As análises foram realizadas à temperatura de 20°C e tensão de 15 kV. A amostra foi injetada hidrodinamicamente (0,5 psi por 10 s) e a detecção foi feita em 214 nm. Nestas condições a LTG e o padrão interno (PI), lidocaína, puderam ser analisados em menos de 7 minutos. A HF-LPME foi avaliada no modo de 3 fases, usando 500 ?L de plasma e 3,5 mL de solução fosfato de sódio 50 mmol L-1 pH 9,0 como fase doadora. O solvente utilizado para impregnar a fibra foi o 1-octanol. Como fase aceptora foram utilizados 60 ?L de solução de ácido clorídrico pH 4,0. Para avaliação da DLLME, foi necessária uma etapa de pré-tratamento da amostra (500 ?L de plasma) com 1 mL de acetonitrila. Após isto, 1,3 mL do sobrenadante foram adicionados a 4 mL de solução fosfato de sódio 50 mmol L-1 pH 9,0 e 120 ?L de clorofórmio (solvente extrator) foram injetados nesta amostra aquosa e 165 ?L de fase sedimentada foram recuperados. As características de desempenho analítico para ambos os métodos foram avaliadas, sendo obtida linearidade na faixa de concentração plasmática de 1-20 ?g/mL e limite inferior de quantificação (LIQ) de 1 ?g mL-1. Os ensaios de precisão e exatidão apresentaram valores de acordo com os guias oficiais. Além disso, os métodos foram seletivos, não apresentaram efeito residual e as amostras foram estáveis. Os valores de recuperação foram de 54,3 e 23% para HF-LPME e DLLME, respectivamente. Os métodos validados foram aplicados com sucesso em amostras de plasma de pacientes epilépticos em tratamento com a LTG. Além disso, as duas técnicas foram comparadas e a HF-LPME apresentou vantagens em relação à DLLME, mostrando ser uma técnica promissora para análise de matrizes complexas, com reduzido consumo de solvente orgânico e possibilidade de automação. / Lamotrigine (LTG) is an antiepileptic drug, which belongs to the class of phenyltriazine that can be used in the treatment of new-onset and refractory epilepsy. Due to its high interindividual variability, drug interactions and the adverse effects presented during the LTG administration, therapeutic drug monitoring is very important to dose adjustment and to avoid toxicity effects. Thus, the goal of this study was to develop and validate two microextraction techniques: the hollow fiber liquid-phase microextraction (HF-LPME) and the dispersive liquid-liquid microextraction (DLLME) to analyze LTG in plasma samples of epileptic patients. First of all, the eletroforetic conditions were optimized. A fused-silica uncoated capillary with 75 ?m internal diameter, and 50 cm effective length was used. The 2-(N-morpholino)ethanesulfonic acid (MES) 130 mmol L-1 pH 5.0 was chosen as background electrolyte (BGE). The temperature and the voltage were kept constant at 20°C and 15 kV respectively. For sample injection, hydrodynamic injection mode was used, with a pressure of 0.5 psi applied for 10 s. The wavelength was set at 214 nm. Under final conditions, LTG and the internal standard (IS) lidocaine were analyzed in less than 7 minutes. HF-LPME was evaluated in the three phase mode. The analyte was extracted from 4.0 mL of a basic donor phase (composed of 500 ?L of plasma and 3.5 mL of sodium phosphate solution 50 mmol L-1 pH 9.0) into an organic phase composed of 1-octanol immobilized in the pores of the hollow fiber, and further into an acidic acceptor phase (hydrochloric acid solution pH 4.0) placed in the lumen of the fiber. To evaluate DLLME, the plasma samples were pretreated to remove the proteins, and 500 ?L of plasma sample was mixed with 1 mL of acetonitrile. After that, 1,3 mL of the upper layer was added to 4 mL of sodium phosphate solution 50 mmol L-1 pH 9.0, and 120 ?L of chloroform (extracting solvent) was rapidly injected in the aqueous sample and 165 ?L of the sedimented phase was collected. Under the optimized conditions, both methods were linear over the plasmatic concentration range of 1.0-20.0 ?g mL-1 and the lower limit of quantification (LLOQ) was 1.0 ?g mL-1. Both methods showed good precision, accuracy, selectivity to LTG, with no carryover and the samples were stable under the studied conditions. The recovery were 54,3 and 23% to HF-LPME and DLLME respectively. The validated methods were successfully applied for the quantification of LTG in plasma samples of epileptic patients. The techniques were compared and HF-LPME was more advantageous for being more suitable to analysis of complex matrices using small amount of organic solvent, and also can be automated.

Plugged and abandoned well pads throughout the Uintah Basin face reclamation challenges due to factors including a harsh climate, invasive species, and high salt loads. Finding ways to alleviate soil sodicity could improve soil reclamation success. Gypsum, sulfur, activated carbon, and Biochar are being applied to improve soil parameters negatively impacted by sodicity, but the direct impact of these amendments on Uintah Basin soils is still largely unknown. The aim of this study was two-fold. (1) Evaluate the effectiveness of gypsum, sulfuric acid, Biochar, activated carbon, and combinations of these amendments in reducing the impact of soil sodicity of the Desilt and Conglomerate soils by measuring amendment impact on percent dispersion, saturated hydraulic conductivity, crust bulk density, infiltration, and crust formation. (2) Compare a crust bulk density method using ImageJ to the clod wax density method and a modified linear extensibility percent equation to the linear extensibility percent equation to assess whether the novel methods can be used to accurately measure and calculate soil crust bulk density and shrink swell potential while reducing human error and analysis time.

Non-destructive testing (NDT) techniques are critical to ensure integrity and safety of engineered structures. Structural health monitoring (SHM) is considered as the next step in the field enabling continuous monitoring of structures. The first part of the thesis concerns NDT and SHM using guided waves in plates, or Lamb waves, to perform imaging of plate structures. The imaging is performed using a fixed active array setup covering a larger area of a plate. Current methods are based on conventional beamforming techniques that do not efficiently exploit the available data from the small arrays used for the purpose. In this thesis an adaptive signal processing approach based on the minimum variance distortionless response (MVDR) method is proposed to mitigate issues related to guided waves, such as dispersion and the presence of multiple propagating modes. Other benefits of the method include a significant increase in resolution. Simulation and experimental results show that the method outperforms current standard processing techniques. The second part of the thesis addresses transducer design issues for resonant ultrasound inspections. Resonant ultrasound methods utilize the shape and frequency of the object's natural modes of vibration to detect anomalies. The method considered in the thesis uses transducers that are acoustically coupled to the inspected structures. Changes in the transducer's electrical impedance are used to detect defects. The sensitivity that can be expected from such a setup is shown to highly depend on the transducer resonance frequency, as well as the working frequency of the instrument. Through simulations and a theoretical argumentation, optimal conditions to achieve high sensitivity are given.

Este trabajo ha estado dirigido al estudio de un proceso eficaz de separación que posibilite la recuperación de zinc de efluentes de decapado ácido de elevada toxicidad, así como su posterior concentración en una fase de características físico-químicas adecuadas para posibilitar su reciclado en baños electrolíticos. Para ello se propone la extracción líquido-líquido no dispersiva como tecnología limpia de elevada eficacia y con bajo requerimiento energético.Tras una exhaustiva revisión bibliográfica, se seleccionan el fosfato de tributilo y el agua de red como agentes extractante y reextractante respectivamente. A lo largo del trabajo y tras una etapa previa dirigida a la evaluación de la viabilidad técnica del proceso, se caracterizaron experimentalmente las reacciones responsables de las etapas de extracción y reextracción, así como la cinética del proceso de separación, para a continuación plantear el modelo matemático y determinar los parámetros característicos del sistema necesarios para el diseño y optimización del proceso de separación-concentración de zinc de efluentes de decapado ácido metálico. / The work was focused on the study of the recovery of zinc from spent pickling effluents, under conditions that permitted the recovery of electrolytic grade metal, thus, reducing the effluent toxicity and with valorisation, at the same time, of the component of higher added value. After a deep literature review, non dispersive solvent extraction using tributyl phosphate (TBP) and service water as extraction and back extraction agents, respectively, was selected as the best separatión alternative. The work started with the analysis of the process viability and included an experimental design of the equilibrium, and kinetics of the phenomena involved in the metal valorisation. The kinetic analysis of the membrane assisted process of zinc recovery from spent pickling effluents was carried out, obtaining the mathematical model and parameters needed for design and optimisation of the metal separation step in a valorisation process.

For the automotive sector, plastics play the most important role when designing interior and exterior parts for cars. Currently, most parts are made from petroleum-based plastics but alternatives are needed to replace environmentally harmful materials while providing the appropriate mechanical performance and preferably reduce the cost for the final product. The objective of this work was to explore the use of soy flakes as natural filler in a composite with polypropylene and to investigate the mechanical properties, water absorption and thermal behaviour. For a better understanding of the filler, the soy flakes were characterized extensively with analytical and microscopic methods. Two types of soy fillers were investigated, soy flakes, provided by Bunge Inc., with a 48 wt-% protein content and an industrial soy based filler with 44 wt-% protein content and provided by Ford. The size of the soy flakes after milling was mainly between 50 and 200 µm and below 50 µm for the industrial filler. The aspect ratio for all filler was below 5. The soy flakes were used after milling and subjected to two pre-treatment methods: (1) one hour in a 50 °C pH 9 water solution in a 1 : 9 solid-liquid ratio; (2) one hour in a 50 °C pH 9 1M NaCl solution in a 1 : 9 solid-liquid ratio. A control filler, without pre-treatment was considered. The soy flakes were also compared to an industrial soy based filler provided by Ford (soy flour (Ford)). The thermogravimetric analysis showed an onset of degradation at 170 °C for the treated filler (ISH2O and ISNaCl) and 160 °C for the untreated filler. The biocomposites formulation consisted of 30 wt-% filler, and polypropylene with/without 0.35 wt-% anti-oxidant Irganox 1010 and with/without the addition of MA-PP as coupling agent. All biocomposites were compounded in a mini-extruder, pressed into bars by injection moulding and tested subsequently. The mechanical properties of the biocomposites are promising. An increase of the E-modulus was observed when compared to pure polypropylene. The addition of MA-PP as coupling agent increased the yield strength of the biocomposites. When pure polypropylene and the biocomposites were compared no difference could be seen for their yield strength. The thermal behaviour deduced from differential scanning calorimetry, revealed a similar behaviour for the biocomposites and the pure polypropylene. Only the samples treated in the presence of NaCl and without a coupling agent, appear to have a slightly higher degree of crystallinity. The melt flow index was slightly increased for the biocomposites containing soy flakes pre-treated with NaCl and decreased for biocomposites containing the soy flour. The water absorption behaviour of the biocomposites was quite similar at the beginning with a slightly lower absorption for the materials with coupling agent. After three months, all samples except the ones treated with water showed a weight loss that can be due to the leaching of the water soluble components in the untreated filler and the NaCl treated filler. In conclusion, soy flakes represent an attractive filler when used in a polypropylene matrix if an aqueous alkaline pre-treatment is performed. The aqueous alkaline extraction also leads to the recovery of the proteins that can be used in food products while the remaining insoluble material is used for the biocomposites, avoiding the competition with the use of soy for food products...