Solid state synthesis of layered, rotationally disordered intergrowths consisting of rock salt (MX) and hexagonal (TX2) constituents in various sequences [(MX)1+δ]m[TX2]n is carried out by developing structural and compositional prototypes of the desired product, using fine control of the elemental reactants and then annealing at low temperature to facilitate self-assembly. (M = Sn, La, Eu; T = V, Mo.) The remarkable rotational disorder in these systems - in contrast to traditional misfits - and their proven applications in thermal, electrical and thermoelectric disciplines make them a useful group of materials for demonstrating control of reaction pathways of solid state reactions using low temperatures and short times. The synthesized materials are structurally characterized using X-ray diffraction (XRD), X-ray reflectivity (XRR), and Scanning Transmission Electron Microscopy (STEM). Electrical characterization is carried out on patterned samples using the Van der Pauw method of resistivity and the Hall effect method. Composition of the samples is determined using wavelength dispersive electron probe microanalysis (EPMA). Time domain thermoreflectance is used to determine the cross plane thermal conductivity. The family of [(SnSe)1.05]m(MoSe2)n (m = n = 1, 2, 3, 4), which possess the same composition but different unit cell thicknesses, shows that there is no correlation between c-axis unit cell thickness and cross plane thermal conductivity. The family of structural isomers [(SnSe)1.05]4[MoSe2]4, [(SnSe)1.05]3[MoSe2]3[(SnSe)1.05]1[MoSe2]1, [(SnSe)1.05]3[MoSe2]2[(SnSe)1.05]1[MoSe2]2, [(SnSe)1.05]2[MoSe2]3[(SnSe)1.05]2[MoSe2]1,[(SnSe)1.05]2[MoSe2]1[(SnSe)1.05]1[MoSe2]2[(SnSe)1.05]1[MoSe2]1 and [(SnSe)1.05]2[MoSe2]2[(SnSe)1.05]1[MoSe2]1[(SnSe)1.05]1[MoSe2]1 have the same c-axis lattice thickness and absolute composition but have different numbers of [(SnSe)1.05]/[MoSe2] interfaces. Thermal conductivity studies carried out on these showed no correlation with the interface density. (LaSe1-x)1.17(VSe2-y)n (n = 2, 3, 4) feature a family of compounds that self-assemble at higher than usual temperatures. They form non-stoichiometric moieties with unique structural proclivities including La vacancies and V interstitials compared to other ferecrystals or previous misfits. The designable electrical properties show evidence of charge transfer. (EuSe)1+δ(VSe2)n (n = 1, 2, 3) is a family of materials that complements the investigation of Ln-based ferecrystals. They show evidence of multiple M oxidation states. These compounds highlight the use of rational design of structure and composition to tune properties. This dissertation includes previously published and unpublished co-authored material. / 10000-01-01

Nous avons cherché à fournir une estimation précise de la conductivité électrique des tissus cérébraux humains en clinique, en utilisant une stimulation pulsée locale de faible intensité. Méthodes : À l'aide de l'approximation quasi-statique des équations de Maxwell, nous avons établi un modèle analytique du champ électrique généré par les électrodes intracérébrales stéréotaxiques-EEG (SEEG). Nous avons couplé ce modèle de champ électrique avec un modèle de l'interface électrode-électrolyte pour fournir une expression analytique explicite de la conductivité du tissu cérébral basée sur la réponse enregistrée du tissu cérébral à la stimulation. Résultats: Nous avons validé notre modèle biophysique en utilisant i) des solutions salines calibrées en conductivité électrique,ii) des tissus cérébraux de rat, et iii) des données électrophysiologiques enregistrées en clinique chez sept patients épileptiques au cours de la SEEG. Nous avons trouvé une possible corrélation entre la conductivité et le caractère épileptique du tissu. Conclusion: Cette nouvelle méthode basée sur un modèle offre une estimation rapide et fiable de la conductivité électrique des tissus cérébraux en tenant compte des contributions de l'interface électrode-électrolyte. Signification: Cette méthode surpasse les mesures standard de bioimpédance. L'application pour le diagnostic est envisagée puisque les valeurs de conductivité diffèrent fortement lorsqu'elles sont estimées dans le tissu cérébral sain versus hyperexcitable. / We aimed at providing an accurate estimation of human brain tissue electrical conductivity in clinico, using local, low-intensity pulsed stimulation. Methods: Using the quasi-static approximation of Maxwell equations, we derived an analytical model of the electric field generated by intracerebral stereotactic-EEG (SEEG) electrodes. We coupled this electric field model with a model of the electrode-electrolyte interface to provide an explicit, analytical expression of brain tissue conductivity based on the recorded brain tissue response to pulse stimulation. Results: We validated our biophysical model using: i) saline solutions calibrated in electrical conductivity, ii) rat brain tissue, and iii) electrophysiological data recorded in clinico from two epileptic patients during SEEG. Conclusion: This new model-based method offers a fast and reliable estimation of brain tissue electrical conductivity by accounting for contributions from the electrode-electrolyte interface. Significance: This method outperforms standard bioimpedance measurements since it provides absolute (as opposed to relative) changes in brain tissue conductivity. Application for diagnosis is envisioned since conductivity values strongly differ when estimated in the healthy vs. hyperexcitable brain tissue.

A pesquisa teve como objetivo estudar procedimentos para a condução dos testes de deterioração controlada, envelhecimento acelerado, condutividade elétrica e lixiviação de potássio, procurando-se verificar sua eficiência para identificação de diferentes níveis de vigor de lotes de sementes de melão (Cucumis melo L.). Para tanto, o estudo foi conduzido em duas etapas, utilizando-se cinco lotes de sementes dos híbridos AF-646 e AF-682. Na primeira foram realizados os testes de germinação, primeira contagem de germinação, Método Agroflora, emergência de plântulas em casa de vegetação e estudos específicos para os testes de deterioração controlada (graus de umidade de 18%, 21% e 24%, a 45ºC, durante 24 e 48 horas), de envelhecimento acelerado, com e sem solução salina (períodos 48, 72 e 96 horas, a 38ºC ou 41ºC), de condutividade elétrica (temperaturas de 20ºC, 25ºC e 30ºC, volumes de 50 e 75mL de água, 25 e 50 sementes e períodos de 1, 2, 4, 8, 12, 16, 20 e 24 horas) e de lixiviação de potássio (25 e 50 sementes, 50 e 75mL de água, a 25ºC e 30ºC, durante 30, 60, e 90 minutos, 2h, 2h e 30 minutos, 3, 4 e 5 horas). Os procedimentos considerados mais promissores para cada teste, nesta primeira fase, foram comparados na segunda etapa, que também incluiu os testes de germinação, primeira contagem de germinação, Método Agroflora e emergência de plântulas em casa de vegetação. Diante dos resultados obtidos, concluiu-se que os testes de deterioração controlada (24%/45ºC/24h) e de envelhecimento acelerado (procedimento tradicional e com solução salina), utilizando a combinação 41ºC/72h, apresentam sensibilidade suficiente para avaliação do potencial fisiológico de sementes de melão. O teste de condutividade elétrica não constitui em opção eficiente para avaliação do vigor das sementes, enquanto o teste de lixiviação de potássio necessita de estudos adicionais para adequar sua metodologia e viabilizar a sua utilização para sementes de melão, considerando-se, inclusive, os prováveis efeitos do genótipo. / This research was conducted to study and select procedures for the controlled deterioration, accelerate aging, electrical conductivity and potassium lixiviation tests, to verify their sensitivity to identify different vigor levels of melon (Cucumis melo L.) seed lots. Five seed lots each from the hybrids AF-646 and AF-682 were used. In the first experimental stage, the following tests were performed: germination, germination first count, Agroflora Method and seedling emergence. Specific studies were also conducted to the following tests: controlled deterioration (seed moisture content of 18%, 21% and 24%, at 45ºC, for 24 and 48 hours), traditional accelerated aging, saturated salt accelerated aging (for 48, 72 and 96 hours, at 38 o C or 41 o C), electrical conductivity (25 or 50 seeds imbibed in 50mL or 75mL water, 20 o C, 25 o C and 30 o C, for 1, 2, 4, 8, 12, 16 and 20 hours) and potassium leachate (25 or 50 seeds, imbibed in 50mL and 75mL, at 25 o C and 30 o C, for 30, 60, 90, 120, 150, 180, 240 and 300 minutes). The procedures considered the most promising for each test in the first stage were compared, in the second stage. The later stage also included germination, germination first count, Agroflora Method and seedling emergence tests. From the results, it was concluded that controlled deterioration (24%/45 o C/24h) and accelerate aging (traditional procedure and salt saturated) tests, using the 41 o C/72h combination, showed to be sufficiently sensitive for the evaluation of the physiological potential of melon seeds. The electrical conductivity test does not constitute an efficient option for the vigor evaluation, while the potassium lixiviation test needs further studies in order to adjust its methodology and enable its use for melon seeds, also considering the probable genotype effects.

A correlação entre as medidas de condutividade elétrica e propriedades físico-químicas do solo é uma das linhas de estudo que vem sendo exploradas onde os conceitos de agricultura de precisão estão mais avançados. Este estudo teve como objetivo avaliar a eficiência do monitoramento da condutividade elétrica do solo a partir do desenvolvimento de dois sistemas. O primeiro, denominado de Resistência Elétrica do Solo (RES), consiste em definir a condutividade elétrica de um material através de uma amostra de dimensões conhecidas, para medir a sua resistência elétrica utilizando dois eletrodos. O segundo, denominado de Duas Pontas (DP), consiste em definir a condutividade elétrica de um material aplicando uma corrente elétrica em uma amostra para medir a alteração no potencial elétrico, gerado pelo meio em que a corrente elétrica transitou, utilizando dois eletrodos dispostos linearmente. Para a avaliação dos resultados obtidos pelos sistemas desenvolvidos foi utilizado como referência um sistema comercial de origem norte americana e algumas propriedades do solo. Os equipamentos de condutividade elétrica do solo foram aplicados em duas áreas pertencentes à Escola Superior de Agricultura “Luiz de Queiroz” e em época distintas. Na Área 1, com 4,97 ha, o levantamento dos dados foi feito na primeira quinzena de Agosto de 2003 e na Área 2, com 1,3 ha, o levantamento dos dados foi feito na segunda quinzena de Dezembro de 2003. Após a aquisição dos dados experimentais foram feitas análises estatísticas descritivas e exploratórias, análises geoestatísticas, construção de mapas de superfície, análises de correlação e regressão linear múltipla a fim de avaliar os sistemas. De acordo com a metodologia desenvolvida e análises de funcionamento dos equipamentos, foi possível verificar que os sistemas construídos para a coleta, transformação e armazenagem dos dados foram eficientes no levantamento dos pontos amostrais. No entanto os sistemas de condutividade elétrica do solo não apresentaram a eficiência desejada no monitoramento das propriedades do solo em ambas as áreas experimentais. Quando os sistemas desenvolvidos foram comparados ao sistema comercial, também foi possível observar que não houve correlação no monitoramento, o que sugere a necessidade da continuidade e aprofundamento no desenvolvimento desses sistemas. / The correlation between electrical conductivity and physical-chemical properties of the soil is one of the research areas that have been explored where precision agriculture concepts are more advanced. This study had the objective of evaluating the soil electrical conductivity mapping efficiency of different measuring systems. The first one, known as Electrical Resistance of the Soil consists in defining the electrical conductivity of any given material using a sample of known dimensions, to measure its electrical resistance using two electrodes. The second one, the Two Edges method, consists in defining the electrical conductivity of a material applying an electric current in a sample to measure any change on the electric potential, generated by the environment in which the electric current transited through, using two linearly displaced electrodes. To evaluate the results obtained by the developed systems some soil properties and a commercial soil electrical conductivity measuring system where used as guidelines. The soil electrical conductivity equipments mapped two fields, at the Escola Superior de Agricultura “Luiz de Queiroz”. In Field 1 (4,97 ha) the data collecting process took place in the first fortnight of august 2003, and, in Field 2 (1,3 ha), the sampling process took place in the second fortnight of December 2003. After the acquisition of the experimental data, descriptive and exploratory statistical and geostatistical analysis were made, electrical conductivity surface maps were obtained and correlation and multiple linear regression analysis, in order to evaluate both systems, were made. In accordance to the developed methodology and analysis of the equipment, it was possible to check that the systems developed to acquire, transform and store the data were efficient in mapping the sampling points. However, the soil electrical conductivity systems did not show the desired efficiency in mapping the soil properties in both experimental fields. When the developed systems were compared to a commercial one it was also possible to observe that there was no correlation in the measurements, which suggests the necessity of new developments on these systems.

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / Diante da importÃncia sÃcio-econÃmica do cajueiro para regiÃo nordeste do Brasil bem como as dificuldades relacionadas à escassez hÃdrica e qualidade de Ãgua para irrigaÃÃo, objetivouse estudar o desenvolvimento de clones de cajueiro anÃo precoce em diferentes estÃdios de desenvolvimento sob irrigaÃÃo com Ãgua salina. O primeiro experimento objetivou avaliar a germinaÃÃo e o desenvolvimento inicial de plÃntulas de cajueiro anÃo-precoce (clones: CCP 06, BRS 189, BRS 226 e BRS 265), em ambiente protegido e irrigadas com diferentes soluÃÃes salinas, visando observar respostas diferenciadas entre os clones. Os tratamentos foram dispostos em esquema fatorial 5 x 4 com quatro repetiÃÃes, referentes a soluÃÃes salinas ajustadas para as condutividades elÃtricas (CEa) (0, 3, 6, 9 e 12 dS m-1), e 4 clones de cajueiro (CCP 06, BRS 189, BRS 226 e BRS 265). Trinta dias apÃs a emergÃncia das plÃntulas, os dados foram coletados e submetidos à anÃlise estatÃstica. Todas as variÃveis de emergÃncia foram influenciadas pela salinidade. A irrigaÃÃo com Ãgua salina proporcionou um acrÃscimo nos teores de Na e Cl nas diversas partes das plantas, afetando negativamente todas as variÃveis de crescimento inicial dos clones de cajueiro anÃo precoce. Sendo o clone CCP 06 o mais tolerante a salinidade comparado aos demais clones estudados. O segundo experimento objetivou avaliar o desenvolvimento de plantas de cajueiro anÃo precoce clone BRS 189 sob irrigaÃÃo com Ãgua salina. O experimento foi conduzido no Campo Experimental de Pacajus da Embrapa AgroindÃstria tropical. Mudas do clone BRS 189, sobre porta enxerto do clone CCP 06, foram transplantadas para solo e a partir do segundo mÃs iniciou-se a aplicaÃÃo dos tratamentos. Os tratamentos foram dispostos em blocos ao acaso com quatro repetiÃÃes e quatro plantas por parcela experimental, referentes Ãs soluÃÃes salinas ajustadas para as condutividades elÃtricas (CEa) (0,8, 3,0, 6,0, 9,0 e 12,0 dS m-1). Decorridos cinco meses obteve-se os dados e aplicou-se anÃlise estatÃstica. Todas as variÃveis de desenvolvimento e a MSF foram influenciadas pela salinidade. Das trocas gasosas apenas a transpiraÃÃo foi afetada pela salinidade. A salinidade limite encontrada no presente estudo foi de CEa de 1,56 dS m-1 para diminuiÃÃo no rendimento potencial de atà 10% . / Considering the socio-economic importance of cashew to the Brazilian northeast and the northeastern problems with water scarcity and quality of irrigation water, the objective of this work was set to study the development of dwarf cashew clones at different stages of development under irrigation with saline water. The first experiment was aimed at evaluating the germination and early growth of seedlings of precocious dwarf cashew (clones: CPC 06, BRS 189, BRS 226 and BRS 265) in greenhouse when irrigated with different salt solutions, in order to observe the differences between the respective responses. The treatments were arranged in a 5 x 4 factorial with four replications, referring y to saline solutions with respective salinities corresponding to the electrical conductivities (ECw) 0, 3, 6, 9 and 12 dS m-1, and four cashew clones (CCP 06 , BRS 189, BRS 226 and BRS 265). Thirty days after seedling emergence, the data were collected and analyzed statistically. All emergence variables were influenced by the salinity. The irrigation with saline water resulted in increased levels of Na+ and Cl- in different plant parts, adversely affecting all the variables of the initial growth of the dwarf cashew clones, with the CCP 06 clone showing the highest salinity tolerance among the clones. The second experiment was aimed at evaluating the growth of dwarf cashew clone BRS 189 under irrigation with saline water. The experiment was conducted at the Pacajus Experimental Field of the Embrapa AgroindÃstria tropical. The BRS 189 seedlings on the CCP 06 clone rootstock, were transplanted to the ground and subjected to the treatments, from the second month onwards. The treatments were arranged in blocks with four replications and four plants per plot, refering to saline solutions corresponding to the electrical conductivities (ECw) 0.8, 3.0, 6.0, 9.0 and 12.0 dS m-1. After five months, the data were obtained, and subjected to statistical analysis. All the development variables and the leaf dry mass (LDM, or MSF) were influenced by salinity. Only perspiration (of the gas exchanges) was affected by salinity. The salinity limit found in this study corresponded to an electrical conductivity of 1.56 dS m-1, to a fall in potential yield of up to 10%

A solução sólida céria-samária é uma das principais candidatas para aplicação como eletrólito sólido em células a combustível de óxido sólido, devido sua alta condutividade iônica em temperaturas intermediárias (500-750 ºC) de operação. Um dos problemas ainda não solucionados com relação a este material é sua relativamente baixa sinterabilidade. Nesse trabalho foi utilizado o método de sinterização em duas etapas visando melhorar a densificação com reduzido tamanho médio de grãos. Soluções sólidas comercial e obtida por mistura de óxidos de composição Ce0,8Sm0,2O1,9 foram utilizadas. Para fins comparativos também foi utilizado o método denominado sinterização em duas etapas tradicional que visa a obtenção de amostras densas independentemente do tamanho médio de grãos. Resultados de densidade aparente e retração linear revelaram que ambos os tipos de amostras têm comportamento distinto. Para a solução sólida comercial, a retração total até 1400 ºC foi de ~18%. Só foram obtidos resultados de densidade significativos ao utilizar temperaturas elevadas (igual ou superior a 1300 ºC). Para o material obtido por mistura de óxidos não foi possível atingir densidades maiores que 90% da densidade teórica. A sinterização em duas etapas tradicional produziu amostras densas, da mesma forma, que a não-tradicional, mas com tamanhos de grãos consideravelmente maiores. Amostras sinterizadas por ambos os processos foram analisadas por espectroscopia de impedância para a determinação da condutividade elétrica em função da temperatura, e não apresentaram variação significativa nas condutividades intra e intergranular. A sinterização em duas etapas não resultou em melhorias na densificação e nem na condutividade elétrica das amostras. Entretanto, a redução obtida no tamanho médio de grãos pode melhorar as propriedades mecânicas. / Samaria-doped ceria solid solution has been proposed to be used as solid electrolyte in Solid Oxide Fuel Cells due to its high ionic conductivity at intermediate temperatures (500-750 ºC). One of the main problems related to this solid solution is the relatively low sinterability. In this work, sintering of powder compacts was carried out by the two-step sintering method to improve the densification with simultaneous reduction of the mean grain size. Samaria-doped ceria, both commercial and prepared by solid state reactions, with composition Ce0.8Sm0.2O1.9 were investigated. For comparison purposes, the traditional two-step sintering method, by which dense specimens are produced, was also utilized. Apparent density and linear shrinkage results showed distinct features depending on the type of specimen. Total linear shrinkage for commercial solid solution up to ~ 1400 ºC was 18%, but high density values were obtained only for sintering experiments conducted at high temperatures ( 1300 ºC). Specimens prepared by solid state reactions did not attain density values higher than 90% of the theoretical one. The traditional method produced dense specimens as well as the two-step sintering, although the grain size was considerably higher in the former. Specimens sintered by the two methods were used for electrical conductivity measurements. No significant variation in both the grain and the grain boundary conductivities was obtained. The two-step sintering did not allow any improvement in the densification and in the electrical conductivity of samaria-doped ceria. However, the decrease in the mean grain size may contribute to improve the mechanical properties of this solid solution.

A zircônia estabilizada com ítria é um material com diversas aplicações tecnológicas. Uma de suas aplicações é como eletrólito sólido em células a combustível de óxido sólido. Os pós de zircônia estabilizada com ítria disponíveis comercialmente densificam a temperaturas superiores a 1400 ºC. Redução na temperatura de sinterização da zircônia seria muito útil, pois permitiria a realização da sinterização simultânea (co-firing) do eletrólito sólido e do anodo, implicando em redução de custo do processo na fabricação de células a combustível. Neste trabalho, os efeitos produzidos do Co na densificação da 8YSZ, principalmente em baixos teores do aditivo, foi estudado, como também a condutividade elétrica da zircônia-estabilizada com ítria, visando determinar o efeito da adição de Co. Foram preparados compactos com carbonato de cobalto e 8YSZ comercial em composições 8YSZ + x% mol Co com x = 0; 0,025; 0,05; 0,1; 0,25; 0,5; 1; 2; 3; 4; 5; 7,5 e 10, por prensagem seguida de sinterização ao ar em diversas temperaturas e tempo de patamar. Os compactos sinterizados foram caracterizados por diversas técnicas. A espectroscopia Raman e a difração de raios X permitiram identificar o Co3O4 como fase predominante após a sinterização, quando o aditivo excede o limite de solubilidade. A densidade sinterizada aumentou com a adição de pequenos teores de Co, mas não foi suficiente para reduzir a temperatura de sinterização abaixo de 1400 ºC. O tamanho médio de grãos aumentou com a temperatura de sinterização. A condutividade elétrica diminui com a adição de Co para teores ³ 1% mol, mas apresenta pequeno aumento para teores de 0,025% mol. / Yttria stabilized zirconia has a wide range of applications including electrochemical devices, oxygen sensors and permeable membranes. Yttria stabilized zirconia is the preferred solid electrolyte in current solid oxide fuel cells. Commercially available yttria stabilized zirconia powders are usually sintered at temperatures higher than 1400 ºC. Reduction of the sintering temperature is desirable to allow for co-firing the solid electrolyte and the anode materials, thereby reducing the fabrication cost. In this work, the effects produced by small amounts of Co addition on sintering and on electrical conductivity of 8YSZ were investigated. Green compacts were prepared by uniaxial pressing mixtures of 8YSZ + x mol% Co with x = 0; 0.025; 0.05; 0.1; 0.25; 0.5; 1; 2; 3; 4; 5; 7.5 and 10 followed by sintering at different dwell temperatures and soaking times. Several techniques were used to characterize the sintered compacts. Results of Raman spectroscopy along with those of Xray diffraction allowed for the identification of the cobalt oxide formed (Co3O4) when the solubility limit is exceeded. The sintered density increased with small Co additions. However, the sintering temperature is still around 1400 ºC. The average grain size increased with Co addition and with increase of the sintering temperature. The electrical conductivity remains almost unchanged with Co additions up to ~ 0.5 mol% and decreases for higher additive contents. However, a small increase of the electrical conductivity occurs at 0.025 mol% Co.

Des films minces de W et de W-Cu ont été déposés par co-pulvérisation GLAD à partir de deux cibles opposées de W et Cu. Chaque cible a été focalisée sur le centre du substrat avec un angle d'inclinaison α = 80°. Plusieurs séries d’échantillons ont été réalisées en faisant varier différents paramètres expérimentaux : la pression de travail, l’épaisseur des films ainsi que les intensités du courant des cibles. La nature des films préparés et leurs propriétés ont été étudiées pour comprendre les corrélations entre les caractéristiques structurales et les comportements électriques des films. Les paramètres expérimentaux jouent un rôle fondamental sur la forme des colonnes, leur angle de croissance, et sur la composition élémentaire des films colonnaires de W-Cu. Une variation systématique de ces paramètres a permis de relier certaines caractéristiques morphologiques et structurales aux propriétés de transport électronique dans ces films colonnaires. Le cuivre a été dissout chimiquement afin d’obtenir une structure plus poreuse, ceci dans l’objectif d’améliorer l’anisotropie électrique. Parallèlement à cette approche expérimentale, un modèle théorique a été développé pour comprendre les propriétés de conduction dans les films en tenant compte de la géométrie anisotrope des colonnes. Ce modèle a été appliqué aux films de W et W-Cu bruts et gravés. / W and W-Cu thin films were deposited by the GLAD co-sputtering technique from two opposite targets: W and Cu. Each target was focused on the center of the substrate with a tilt angle of α = 80 °. Several series were prepared changing some experimental parameters: the sputtering pressure, the film’s thickness as well as the target currents. The nature of as-deposited films and their morphological properties were studied in order to understand the correlations between some structural characteristics and electrical behaviors of these structured films. The experimental parameters play a key-role on the shape of the columns, their angle of inclination, and the elemental composition of these W-Cu films. The influence of these parameters on the films morphology was demonstrated and related to the electronic transport properties in these columnar films. The copper was chemically etched in order to obtain a more porous structure, with the aim of improving the electrical anisotropy. A theoretical model was also developed in order to understand the electrical conductivity mechanism in these columnar films taking into account the anisotropic structure of the columns. This model was applied to W, as-deposited W-Cu and etched W-Cu films.

Total body electrical conductivity (TOBEC) is a noninvasive method for the estimation of lean mass in live subjects. Lipid content can be calculated from the body mass measured and the lean mass estimated from TOBEC. I used live American Kestrels (Falco sparverius) to study the accuracy of this method. TOBEC measurements were compared to actual body content determined by Soxhlet fat extraction using petroleum ether as the solvent. TOBEC estimated 73.7% of the variation in lean mass in a sample of 21 kestrels. The use of restraining devices (Vetrap and cardboard cylinders) altered the TOBEC measurement but only by an average of 1.92% and 0.83%, respectively. TOBEC estimated 83.8% of the vii variation in lean mass for 21 kestrel carcasses warmed to 39.8°C. No significant difference was found between the slope or elevation of the calibration lines developed using live or dead kestrels. A significant difference was found between measurements taken at two different positions. Body temperature altered the TOBEC measurements by an average of 1.54% (SE = 0.55) for each 1°C change over a temperature range of 7.0°C (37.3-44.4). The calibration line developed for kestrels was used to estimate lean mass and compute fat mass of migrating kestrels, Sharp-shinned Hawks (Accipiter striatus) and Merlins (Falco columbarius). The average percent fat mass of kestrels trapped during migration at Cape May, New Jersey, was 6.01 % (SE = 1.92, n = 1 2) for males and 8.51 % (SE = 2.00, n = 13) for females. The difference in lean mass between male and female, and between early, mid-season, and late migrating Sharp-shinned Hawks differed significantly during migration. The fat mass of Sharp-shinned Hawks averaged 5.55% (SE = 0.94, n = 53) for males and 10.92% (SE = 0.80, n = 87) for females. Male Merlins had an average fat mass of 18.05% (SE = 3.35, n = 7) and females averaged 14.19% (SE = 3.15, n = 8).

Knowledge of the spatial distribution of soil textural properties at the watershed scale is important for understanding spatial patterns of water movement, and in determining soil moisture storage and soil hydraulic transport properties. Capturing the heterogeneous nature of the subsurface without exhaustive and costly sampling presents a significant challenge. Soil scientists and geologists have adapted geophysical methods that measure a surrogate property related to the vital underlying process. Apparent electrical conductivity (ECa) is such a proxy, providing a measure of charge mobility due to application of an electric field, and is highly correlated to the electrical conductivity of the soil solution, clay percentage, and water content. Electromagnetic induction (EMI) provides the possibility of obtaining high resolution images of ECa across a landscape to identify subtle changes in subsurface properties. The aim of this study was to better characterize subsurface textural properties using EMI mapping and geostatistical analysis techniques. The effect of variable temperature environments on EMI instrumental response, and ECa - depth relationship were first determined. Then a procedure of repeated EMI mapping at varying soil water content was developed and integrated with temporal stability analysis to capture the time invariant properties of spatial soil texture on an agricultural field. In addition, an EMI imaging approach of densely sampling the subsurface of the Reynolds Mountain East watershed was presented using kriging to interpolate, and Sequential Gaussian Simulation to estimate the uncertainty in the maps. Due to the relative time-invariant characteristics of textural properties, it was possible to correlate clay samples collected over three seasons to ECa data of one mapping event. Kriging methods [ordinary kriging (OK), cokriging (CK), and regression kriging (RK)] were then used to integrate various levels of information (clay percentage, ECa, and spatial location) to produce clay percentage prediction maps. Leave-one-out cross-validation showed that the multivariate estimation methods CK and RK, incorporating the better sampled surrogate ECa, were able to improve the RMSE by 7% and 28%, respectively, relative to OK. Electromagnetic induction measurements provide an important exhaustive layer of information that can improve the quality and resolution of soil property maps used in hydrological and environmental research.