Call number: LD2668 .T4 1986 S237 / Master of Science / Agronomy

The SMAPVEX12 (Soil Moisture Active/Passive Validation Experiment 2012) was carried out over the summer of 2012 in Manitoba, Canada. The goal of the project was to improve the accuracy of satellite-based remote sensing of soil moisture. Data were gathered during a 42-day field campaign with surface measurements on 55 different agricultural fields in south-central Manitoba. The extended duration of the campaign, contrast in soil textures, and variety of crop types over the study region provided an excellent range of soil moisture and vegetation conditions. The study fields ranged from bare to fully vegetated, with volumetric soil moisture levels spanning a range of almost 50%. Remotely sensed data were collected on 17 days by aircraft at 1.4 Ghz with a microwave radiometer at two different resolutions. Observed brightness temperatures from the radiometer showed a typical inverse relationship to the near simultaneous soil moisture measurements from the field. Field-by-field relationships using all sampling dates with both soil and emissivity data were all shown to be significant with the exception of two of the pasture fields and a soybean field. Linear regressions across multiple fields and by flight lines also had statistically significant slopes. The significance of all these relationships improved with the removal of pasture fields from the analysis. On most fields, the sensitivity (slope) of the relationship and correlation coefficient (R2) between emissivity and observed soil moisture increased when vegetation and roughness effects were taken into account. The b parameter that relates vegetation water content to optical depth in the tau-omega model was optimized using the collective slope and R2 values of the individual fields. A b parameter value of 0.06 for horizontal polarization and 0.13 for vertical polarization were found to be optimal across the range of all fields in this analysis. / May 2016

Sensor applications are becoming increasingly important as products are now being requested to be more and more intelligent and safe. As the costs involved in sensor technology decrease its usage will spread to new market segments including new areas with products that have never previously used such functionalities, including, wood fibre based products for packaging, hygiene or graphical use. Currently there is a significant interest in developing technology that will allow packages to become interactive and be integrated with digital services accessible on the Internet. In this thesis, the system integration of a hybrid RFID based sensor platform is presented. This proposed platform provides a trade-off between the communication performance and its compatibility with international standards and also includes flexibility in on‐package customization, including the type and number of sensors. In addition it combines the use of traditional silicon based electronics with printed electronics directly onto wood fibre based materials so as to enable the possibility of creating smart packages. Together with the system integration of the sensor platform, five printed moisture sensor concepts that are designed to work with the sensor platform are presented and characterized. Firstly, there is a moisture sensor that shows a good correlation to the moisture content of wood fibre based substrates. The second one involves a sensor that detects high relative humidity levels in the air and the third is an action activated energy cell that provides power when activated by moisture. The fourth one deals with two types of moisture sensors that utilize silver nano-particles in order to measure the relative humidity in the air. The final one is a printable touch sensitive sensor that is sensitive to the moisture contained in the hand. A concept of remote moisture sensing that utilizes ordinary low cost RFID tags has also been presented and characterized. The main focus is thus on system integration to, by combining silicon based electronics with printed electronics, find the most low cost solution with regards to flexibility, sensor functions and still meet the communication standards. / När efterfrågan på mer intelligenta och säkra produkter ökar så ökar även intresset för olika typer av sensorer. När kostnaden för dessa sensorer sjunker så kommer användandet av dessa att utökas till nya marknadssegment som tidigare inte använt denna typ av funktionalitet, som tillexempel pappersbaserade förpackningar, hygienartiklar och papper för grafiskttryck. Det är för närvarande ett stort intresse att utveckla tekniker som tillåter förpackningar att bli interaktiva och integrerade med olika digitala tjänster kopplade till Internet. I denna avhandling så presenteras systemintegrationen av en RFID baserad sensor plattform som tillhandahåller en avvägning mellan kommunikationsprestanda, kompabilitet med internationella standarder och kundanpassningsflexibilitet. Där man direkt på förpackningen kombinerar fördelarna med traditionell kiselbaserad elektronik med trycktelektronik för att kunna skapa intelligenta förpackningar. I avhandlingen presenteras och utvärderas även fem trycka fuktsensorer som är designade att kunna användas tillsammans med sensor plattformen. Den första sensorn mäter fukthalten i cellulosabaserade substrat. Den andra kan detektera höga fukthalter i luften. Den tredje, som aktiveras vid en händelse, producerar en elektrisk ström när den blir fuktig. Den fjärde sensorn använder sig av silverbaserade partiklar i nanostorlek för att mäta fukthalten i luften. Den femte sensorn är en beröringskänslig sensor som ger utslag av fukten i handen. Utöver dessa sensorer så utvärderas även ett koncept med en fuktsensor som kan läsas av på avstånd. Fokus är således att på system integrationsnivå, med hjälp av att kombinera kisel elektronik med tryckt elektronik, hitta den mest kostnadseffektiva lösningen med avseende på flexibilitet, sensor funktionalitet och att även kunna möta kommunikationsstandarderna.

The syntheses and characterization of a series of (NHC)Pd(II) complexes (NHC = N-heterocyclic carbene) are described. A variety of architectures and precursors have been employed to lead to numerous air- and moisture-stable complexes. The use of those complexes as pre-catalysts in cross-coupling (Suzuki- Miyaura, Buchwald-Hartwig) and related (catalytic dehalogenation, £-ketone arylation) reactions is also discussed. A comparison of the activity of a variety of (NHC)Pd complexes as pre-catalysts for cross-coupling reactions was carried out. The results indicate that the activation of those pre-catalysts, leading to the catalytically active [(NHC)Pd(0)] species, was key in assuring high catalytic performance under mild reaction conditions. For the first series of complexes described, (NHC)Pd(allyl)Cl complexes, a better understanding of the process leading to the catalytically active species has permitted us to introduce simple modifications (alkyl or aryl groups at the allyl moiety) that dramatically alter the performance of the complexes by facilitating their activation, decreasing reaction times, catalyst loadings and even allowing reactions to be conducted at room temperature. Catalyst loadings as low as 0.05 mol% can be used for the Suzuki-Miyaura crosscoupling of aryl chlorides and aryl boronic acids at room temperature, leading to the synthesis of poly-ortho-substituted biaryls in excellent yields. This catalyst loading is the lowest ever used for this purpose. The system also allows for the first examples of coupling between aryl chlorides and alkenyl boronic acids at room temperature. When the temperature is raised to 80 ¢ XC for these reactions, a catalyst loading as low as 50 ppm can be used to effectively carry out Suzuki-Miyaura cross-couplings in remarkably short reaction times. As an added advantage, these complexes are air- and moisture-stable and can be prepared in a facile one-pot, multigram scale synthesis from commercially available starting materials in very high yields. The second series of complexes described revolves around the (NHC)Pd(acac)n framework. These complexes are also air- and moisture-stable and can be prepared in a one-step synthesis in high yields from commercially available materials. These complexes were tested forƒn £-ketone arylation and Buchwald-Hartwig amination reactions affording high yields of the desired products, in short reaction times and mild reaction conditions.

Philosophiae Doctor - PhD / The Cape Floristic Region (CFR) of southern Africa is one of the world’s most unique biodiversity hotspots. However, this biodiversity continues to be threatened by habitat loss due to rapid urbanisation, agriculture and alien vegetation encroachment, and now, by future groundwater extraction and climate change. Previous work had shown that soil moisture is important in structuring wetland plant communities at fine-scale. What is not fully known, however, is how the spatial distribution of species at a local scale is related to soil hydrology and what the response in the future of species distributions will be to perturbations arising from changes in climate or subsurface moisture in the future. The current research investigated the water regime of the Restionaceae which is a key family in the Fynbos biome and the implications of possible changes in soil hydrology caused by climate change in communities within this region. The Restionaceae were particularly appropriate because they are shallow rooted perennials with the ability to tolerate a wide range of water regimes which allows them to successfully co-habit within mixed plant communities as segregated clusters along fine-scale hydrologic gradients. Vegetation survey counts for the presence of these species along with measurements of soil water table depth and moisture content data generated from eight small-scale plots (50 x 50 m) were used to investigate the possible hydrological niches and to envision the potential impacts of a substantial reduction in rainfall and an increase in temperature as projected by Global Climate Models (GCMs) on the structure of Restionaceae communities in seasonal wetlands by 2100. A comparative analysis of the effects of two extreme Representative Concentration emission Pathways (RCP2.6 and RCP8.5) on significant hydrological variables to plant water regimes was carried out. The IPCC AR5 report describes the RCP8.5 emissions scenario as the likely ‘business as usual’ scenario where emissions continue to rise through the 21st century while the RCP2.6 scenario assumes that emissions peak between 2010 and 2020 and substantially subside thereafter.

The definition of the principle of effective stress and its implications have been examined for saturated and partly saturated soils. The results of a series of oedometer and all round compression tests of partly saturated and fully saturated soils are presented. These results together with additional experimental data indicate that most soils, from sands right through to clays, exhibit behaviour which, below a critical degree of saturation, cannot be accounted for by the effective stress principle. In sands the critioal degree of saturation appears to be below 50%. In clays, however, the critical degree of saturation is upwards of 85%. An explanation for the observed behaviour of partly saturated soils is offered. It is apparent that structural changes resulting from a change of pressure deficiency in a soil are very different from those resulting from an equivalent change in applied stress. The investigation as a whole indicates that, below the critical degree of saturation, the concept of effective stress in a partly saturated soil is not valid. It is suggested that the term 'intergranular stress' is more suitable than the term 'effective stress' since its use does not imply the validity of the principle of effective stress. The practical significance of the investigation is discussed briefly and the lines along which further research would prove profitable are indicated.

Soil moisture estimation using Sentinel-1 radar data The main aim of this diploma thesis was to find and quantify the relationship between the intensity of backscatter from the Sentinel-1 radar data and the volume soil moisture at the level of agricultural fields. The research was conducted in three areas, in the first part there were two vegetation-free fields near the Thessaloniki (Greece), and information about soil moisture was obtained from own measurements using a thermogravimetric method. The second part drew data from the freely available ISMN database and the research was carried out on agricultural fields during the vegetation season in northwest Germany. The third part used soil moisture data from the Czech Hydrometeorological Institute (ČHMÚ) and the area of interest was two grassed areas of the airport and one agricultural field. Correlation was measured by calculating the determination coefficient and by using the linear regression an equation for calculating the soil moisture from the radar backscatter was compiled. High dependence has been confirmed when VV polarization with constant surface roughness were examined. In the case of surfaces with varying roughness and vegetation cover, only low correlation was found, similarly with using VH polarization. Key words: radar, SAR, Sentinel-1, soil...

A norma brasileira para o projeto de estruturas de madeira foi alterada, recentemente, abandonando o método determinista das Tensões Admissíveis e adotando o método probabilista dos Estados Limites. Seguindo tendência mundial, a atual norma brasileira, estabelece um teor de umidade de referência de 12%, no qual devem ser reportados os resultados dos ensaios. Dificilmente se conseguirá condicionar, a madeira para o ensaio, com um teor de umidade de exatamente 12%, portanto, será necessário corrigir os resultados do ensaio para este teor de umidade. A atual norma brasileira propõe expressões, para fazer esta correção nas propriedades de resistência e de rigidez da madeira, baseando-se em poucos resultados de ensaios. O objetivo deste trabalho é aferir as expressões propostas pela norma brasileira, sugerindo as alterações necessárias. Uma proposta para a correção da densidade aparente, não prevista na norma brasileira, também será estudada. Para garantir uma base experimental adequada, estuda-se a influência do teor de umidade sobre as propriedades de resistência à compressão paralela às fibras, tração paralela às fibras, cisalhamento paralelo às fibras (no plano radial-longitudinal), bem como sobre o módulo de elasticidade longitudinal e a densidade aparente, em sete diferentes espécies de madeira, correspondentes às sete classes de resistência adotadas pela atual norma brasileira. Conclui-se o trabalho apresentando uma proposta para correção das propriedades de resistência e rigidez ao teor de umidade de 12%. Apresenta-se também uma proposta para a correção da densidade aparente. / The Brazilian Code, NBR 7190/97 - Design of timber structures, was revisited, recently, abandoning the Allowable Stress Method and adopting the States Limits Design Method. Following world tendency, the current Brazilian Code, establishes a reference moisture content of 12%, in which the test\'s results should be registered. It is not possible to keep the specimen, for testing, with exactly 12% moisture content, therefore, it will be necessary to correct the results for this moisture content level. The current Brazilian Code proposes expressions, to do this correction in the strength and stiffness properties of wood, based on few test\'s results. The objective of this work is to judge the expressions proposed by the Brazilian Code, proposing the necessary alterations. A proposal for the correction of the specific gravity, not presented in the Brazilian Code, it will also be studied. To this purpose, the influence of moisture content on the strength in compression and tension parallel to grain, shear parallel to grain (in the radial-longitudinal plane), as well as on the stiffness (modulus of elasticity) and specific gravity, in seven different wood species, corresponding to the seven Brazilian Code strength classes were studied. The conclusions presents a proposal for correction of the strength, stiffness properties and specific gravity, to the 12% moisture content level.

Peneiras vibratórias são equipamentos amplamente utilizados em circuitos de cominuição nas mais variadas funções, desde classificação primária, processando blocos de algumas toneladas até em um escalpe de finos para um britador, até mesmo um processo de desaguamento, no qual as telas atuam como filtros, processando polpas que contêm partículas muito finas. Sua utilização tem crescido consideravelmente nos últimos anos, pois quando as peneiras vibratórias são corretamente aplicadas, possibilitam aumentar a eficiência de uma usina a custos razoavelmente baixos. Embora as funções do peneiramento sejam de fácil entendimento, o processo de seleção e dimensionamento dos equipamentos é complexo e sujeito a erros de difícil solução. Quando o minério tem baixa umidade, caso da maioria das aplicações, os dimensionamentos feitos pelos métodos tradicionais apresentam boa correlação com os resultados obtidos nas peneiras industriais. Entretanto, quando a umidade é alta, os cálculos podem apresentar grandes desvios frente ao desempenho real ou simplesmente não funcionar. Este problema é bastante comum em regiões tropicais, como o Norte do Brasil, local com alta incidência de chuvas, onde predominam minérios alterados. O objetivo deste trabalho foi desenvolver um método de dimensionamento de peneira, através de ensaios em laboratório com pequena quantidade de amostras, que permite ao usuário estimar o desempenho de uma peneira industrial no processamento de minérios difíceis com melhor precisão, comparado aos métodos convencionais. As conclusões demonstram a viabilidade técnica do método proposto e seus limites de aplicação. / The vibrating screens are widely used in the comminution circuits for different applications. They can be used for fines removal before a crusher or as a dewatering equipment, where the screening media act as a filter. The screen utilization has been extensively growing in the last years since its accurate operation allows plant efficiency improvements at a minor cost. Although the screening process has an easy understanding, the scale-up and sizing methods can be complex and subject to errors that are difficult to solve. When an ore has low natural moisture, representing most applications, the screen size estimates done by traditional methods normally shows proper correlation compared to industrial screens. However, when the moisture content is high, calculations may present significant deviations when compared to the real operation. This kind of problem is characteristic for tropical regions such as the North of Brazil, where weathered rocks are predominated. The objective of this work was to develop a screen sizing method which allows the user to do an industrial screen performance estimation for difficult high natural moisture ores, based on laboratory test work with reduced quantity of samples, and to provide better accuracy when compared to the results coming from traditional sizing methods. The conclusions demonstrate the technical viability of the method and its application limits.

Master of Science / Department of Animal Sciences and Industry / Micheal J. Brouk / Two studies were conducted that focused on either the accuracy of hand-held near infrared spectrophotometer (NIR) units and two on-farm testing methods compared to conventional 105°C oven drying of corn silage or the use of a starling resistant supplement in total mixed rations (TMR) for lactating dairy cattle. Study 1 evaluated the accuracy of three NIR units (Digi-Star Moisture Tracker, Topcon Agriculture, Fort Atkinson, WI), food dehydrator (FD) (Nesco®, Two Rivers, WI), and a Koster Tester (KT) (Koster Moisture Tester, Inc., Brunswick, OH) to conventional 105°C forced air oven drying. Samples were taken at four Kansas dairy farms and analyzed for DM daily for 20 d. Two calibrations were tested within each NIR unit: NIRu was the DM predicted from the factory-preset calibration, and NIRc was a bias-adjusted DM prediction based on the average difference of oven-dried corn silage and NIRu over the 20-d study. Average oven DM of corn silage was 38.38% ± 0.59 for the 20-d experiment. All three NIRu measurements were lower (P<0.05) than the oven value. While all 3 NIRc predictions were similar (P>0.05) to oven value. KT value was similar (P>0.05) to the oven, while FD value was over estimated DM. (P<0.05). The hand-held NIRS units accurately predicted DM content of the corn silages when the factory preset calibrations were corrected for bias. While the food dehydrator over-estimated the DM of the corn silage and the Koster Tester accurately predicted DM. Study 2 was designed to evaluate the lactation performance of post-peak dairy cattle when using a starling resistant grain supplement. Sixteen prim- and multiparous Holstein cows were housed individually in a tie-stall barn, milked 3x daily, and fed 2x daily. Cows were fed two nutritionally similar diets: 1. TMR with grain in mash form and 2. TMR with grain supplement in a pellet with a 0.953-cm diameter. This study was designed as a single reversal experiment with two 14 d periods with the first 7 d used for an adaptation period and the last 7 d used for data collection in each period. Dry matter intake (DMI), water intake, and milk production was recorded daily. Feed ingredients, TMRS, refusals, and milk samples were collected the last 3 d of each period for analysis. TMRs and refusals were analyzed for particle size distribution with a Penn State Particle Separator. The pelleted supplement had a higher (P<0.05) percentage of DM retained on the 8.0-19.0mm sieve than the mash supplement as the pellet diameter was >8.0mm and could not pass through that sieve. There was no effect of diet (P>0.05) for DMI, feed efficiency, milk component percentage, and protein yield. There was a diet effect (P<0.05) for milk production, fat-corrected milk, energy-corrected milk, solid-corrected milk, and fat yield with lower observed values when cows were fed the pelleted supplement. This leads to the conclusion while a 0.953-cm diameter pellet will reduce starling consumption, it may result in lower milk production of post-peak Holstein cows.