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Barley grain is one of the main sources of feed for ruminants in Canada. Although barley varieties may have similar chemical composition, they exhibit different rumen degradation characteristics and nutrient availabilities. These biological differences may be related to structural chemical make-up or structural features among the varieties. The objectives of this study were to use the in situ technique and two Mid-IR Spectroscopy techniques, Diffuse Reflectance Fourier Transform IR Spectroscopy (DRIFT) and Synchrotron-based Fourier Transform IR Microspectroscopy (SFTIRM) to determine ruminal nutrient availabilities and inherent structural features in the hull, seed and endosperm of six barley varieties (AC Metcalfe, McLeod, CDC Dolly, CDC Helgason, CDC Trey, and CDC Cowboy) and to study the relationships between structural characteristics, mean and median particle size and nutrient availability. The nylon bag technique was used to incubate coarsely dry-rolled barley samples for 0, 2, 4, 8, 12, 24 and 48 h in the rumen of three mature Holstein dry dairy cows, which were ruminally cannulated. The rumen degradation kinetics of dry matter (DM), crude protein (CP) and starch were determined using first order degradation kinetics equations. Results indicated that there were significant differences in the mean and median particle size, degradation kinetics of each individual nutrient (DM, CP, and starch) among the six barley varieties. CDC Helgason showed the lowest degradation rate and extent of all nutrients (DM, CP, and starch) among the six barley varieties with larger particle size. Compared with other five varieties, CDC Helgason may be more suitable for ruminants feeding because of the lowest degradation rate and extent. The results also revealed a strong correlation between median particle size and the rate and extent of rumen degradation.<p> The results also showed that both DRIFT and SFTIR techniques associated with uni- and two multi- variate analyses were capable to efficiently discriminate and classify the inherent molecular structural features among the different varieties of barleys. Uni-variate analyses were conducted using both the DRIFT spectroscopy (hull and whole seed sample) and SFTIR microspectroscopy (endosperm tissue). The results from hull samples showed significant differences in the peak area of aromatic lignin, cellulosic compound, and total carbohydrates (CHO), and the ratio of lignin to cellulosic compound among the six barley varieties. The results from whole seed samples showed significant difference in the peak area and height of Amide I, peak area of total CHO and structural CHO (cellulosic), and the ratio of Amide I to total CHO area, and the ratio of total CHO to structural CHO. Significant differences were also found in the SFTIR results from endosperm tissue. With two multivariate spectral analysis techniques: Agglomerative hierarchical cluster (AHCA) and Principal component analyses (PCA) applied on whole seed sample, the CDC Helgason was distinguished from AC Metcalfe, CDC Dolly, McLeod and CDC Cowboy in fingerprint (1800-800 cm-1) and CHO region (1185-800 cm-1), from AC Metcalfe, McLeod and CDC Cowboy in protein region (1715-1485 cm-1). Information from this study involving probing the seed internal structure of barley may provide a further insight as to why barley varieties exhibit different rumen degradations.

Barley grain is one of the main sources of feed for ruminants in Canada. Although barley varieties may have similar chemical composition, they exhibit different rumen degradation characteristics and nutrient availabilities. These biological differences may be related to structural chemical make-up or structural features among the varieties. The objectives of this study were to use the in situ technique and two Mid-IR Spectroscopy techniques, Diffuse Reflectance Fourier Transform IR Spectroscopy (DRIFT) and Synchrotron-based Fourier Transform IR Microspectroscopy (SFTIRM) to determine ruminal nutrient availabilities and inherent structural features in the hull, seed and endosperm of six barley varieties (AC Metcalfe, McLeod, CDC Dolly, CDC Helgason, CDC Trey, and CDC Cowboy) and to study the relationships between structural characteristics, mean and median particle size and nutrient availability. The nylon bag technique was used to incubate coarsely dry-rolled barley samples for 0, 2, 4, 8, 12, 24 and 48 h in the rumen of three mature Holstein dry dairy cows, which were ruminally cannulated. The rumen degradation kinetics of dry matter (DM), crude protein (CP) and starch were determined using first order degradation kinetics equations. Results indicated that there were significant differences in the mean and median particle size, degradation kinetics of each individual nutrient (DM, CP, and starch) among the six barley varieties. CDC Helgason showed the lowest degradation rate and extent of all nutrients (DM, CP, and starch) among the six barley varieties with larger particle size. Compared with other five varieties, CDC Helgason may be more suitable for ruminants feeding because of the lowest degradation rate and extent. The results also revealed a strong correlation between median particle size and the rate and extent of rumen degradation.<p> The results also showed that both DRIFT and SFTIR techniques associated with uni- and two multi- variate analyses were capable to efficiently discriminate and classify the inherent molecular structural features among the different varieties of barleys. Uni-variate analyses were conducted using both the DRIFT spectroscopy (hull and whole seed sample) and SFTIR microspectroscopy (endosperm tissue). The results from hull samples showed significant differences in the peak area of aromatic lignin, cellulosic compound, and total carbohydrates (CHO), and the ratio of lignin to cellulosic compound among the six barley varieties. The results from whole seed samples showed significant difference in the peak area and height of Amide I, peak area of total CHO and structural CHO (cellulosic), and the ratio of Amide I to total CHO area, and the ratio of total CHO to structural CHO. Significant differences were also found in the SFTIR results from endosperm tissue. With two multivariate spectral analysis techniques: Agglomerative hierarchical cluster (AHCA) and Principal component analyses (PCA) applied on whole seed sample, the CDC Helgason was distinguished from AC Metcalfe, CDC Dolly, McLeod and CDC Cowboy in fingerprint (1800-800 cm-1) and CHO region (1185-800 cm-1), from AC Metcalfe, McLeod and CDC Cowboy in protein region (1715-1485 cm-1). Information from this study involving probing the seed internal structure of barley may provide a further insight as to why barley varieties exhibit different rumen degradations.

Chromium doped crystals exhibit different emitting properties for their different valance species and the host crystals. Ruby shows narrow twin peaks around 694 nm for its Cr3+ ions. Cr4+:YAG has a broadband luminescence range on 1.1~1.6£gm, which is suitable for optical communication. The thesis aims to study the luminescent spectra of Cr ions in different crystal structure (Al2O3 and YAG). Cr concentration dependent spectra indicate Cr3+ moving toward the octahedron sites. It results the change of luminescent spectra and luminescent decay lifetime. Both FTIR and confocal microscopy are used for the investigations. Step-scan FTIR provides the relation of luminescence intensity relating to both wavenumber and delay time, of the external light source.The high numerical aperture optics in the confocal microscope provides higher collection efficiency, and results a better S/N ratio. In addition, Raman spectra are measured. Ruby and sapphire crystals exhibit different Raman spectra, which results from the electronic resonance of the Cr3+ ions in the ruby crystal.

At Cameco mine sites in northern Saskatchewan, naturally occurring elements of concern (EOC) such as As, Ni, Mo, and Se are present in uranium ore bodies. Ferrihydrite (Fh) is found in tailings management facilities (TMF) and is known to sequester arsenates and arsenites. Fh is known to be metastable and undergo phase transformations to goethite (α-FeOOH) and hematite (α-Fe2O3). Reductive conditions are known to be a driving force in Fh transformation and the release of adsorbed As species from the surface. This study uses electrochemistry to control reductive potentials applied to Fh adsorbed As species. Electrochemistry was coupled with attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy to determine the behaviour of adsorbed arsenate and arsenite on the Fh surface. The potentials required to desorb As(III) and As(V) from the Fh surface were negative enough to cause the reduction of water, thus increasing the pH of the solution through the generation of OH-. In order to measure the extent of the pH change a miniature palladium/palladium oxide pH sensor was fabricated in order to make in-situ pH measurements during spectroelectrochemical studies. Additionally, in-situ solution potential (Eh) measurements were made during potential control. It was found that potential induced pH and Eh changes were significant enough to release arsenite from the Fh surface. Arsenate was also found to desorb from Fh during the application of reductive potentials though successive deprotonation leading to a totally deprotonated As(V) species.

Current understanding of molecular-level interactions is inadequate to explain the initial moments of bacterial adhesion. Such information is required to develop appropriate models for bacteria-surface interactions and predictions of cell transport in subsurface environments. Bacterial adhesion is influenced by bacterial surfaces, substratum physical-chemical characteristics, and solution chemistry. Extracellular polymeric substances (EPS), surface proteins, and lipopolysaccharides (LPS) mediate cell adhesion and conditioning film formation via direct bonding to a substrate. The goal of this dissertation is to probe molecular-scale interactions of cell surface macromolecules at mineral surfaces under environmentally-relevant conditions. Four primary investigations are presented in this dissertation. The first study uses in situ attenuated total reflectance (ATR) Fourier transform infrared (FTIR) spectroscopy to reveal that prior to Mn-oxidation via Pseudomonas putida GB-1, cell adhesion to ZnSe is favorable. Subsequent Mn-oxidation results in increased extracellular proteins expression. Conversely, planktonic cell adhesion is inhibited for Mn-oxide coated cells via blocking of surface proteins. The second investigation reveals the formation of inner-sphere complexes between bacteria surface phosphoryl groups and nanohematite (α-Fe₂O₃). Spectra of bacteria (P. aeruginosa PAO1, Shewanella oneidensis MR-1, and Bacillus subtilis) on α- Fe₂O₃ contain peaks indicative of P-OFe inner-sphere bonding. Spectra collected for oxide-adsorbed model P-containing compounds give spectral signatures similar to those P-OFe bonding interactions observed for whole cell and EPS. The behavior of P. aeruginosa serotype 10 LPS in aqueous solutions was investigated in the third study. Ionic strength, pH, and electrolyte composition were varied during collection of ATR-FTIR and dynamic light scattering (DLS) data. Results reveal stable aggregate Na-LPS aggregates, whereas binding of Ca²⁺ to phosphate groups in the lipid A region leads to aggregate reorientation and increased interaction with ZnSe (hydrophobic). DLS data demonstrate decreasing hydrodynamic radius of LPS aggregates with increasing I and decreasing pH. In the fourth investigation, ATR-FTIR was used to probe the solid-solution interface of LPS on surfaces of ZnSe, Ge, α-Fe₂O₃, and α-Al₂O₃ in solutions of varying ionic composition and pH. Na-LPS aggregates remain stable and spectra are biased towards solution phase LPS. Ca-LPS aggregates are disrupted, leading to enhanced interaction with surfaces via hydrophobic (lipid A- ZnSe) and electrostatic (O-antigenhydrophilic surfaces) interactions.

This diploma thesis focuses on the use of infrared spectrometry methods for the analysis of soil samples. The aim of this work was to compare and analyze the soil using the ATR (Attenuated Total Reflectance) and DRIFTS (Diffuse Reflectance Infrared Fourier Transform Spectroscopy) methods and to evaluate the effectiveness of these methods for soil analysis. The results showed that the ATR method is not sufficiently effective and the DRIFT method was used for soil analysis, which proved to be more suitable for the analysis of soil samples.

In many experiments, surfactant adsorption and desorption at solid-liquid interfaces is found to be quite slow, considering that surfactants are small molecules. Attenuated total reflectance Fourier transform infrared spectroscopy was used to study the adsorption, desorption, and exchange of tetradecyltrimethylammonium bromide (C₁₄TABr) at the silicon oxide surface. The exchange of surfactant was monitored using protonated and perdeuterated C₁₄TABr. The data show that exchange of C₁₄TABr between the surface and the bulk solution is very fast, complete exchange occurs in less than 10 seconds. A simple exchange model suggests that the disassociation rate constant of a single monomer is no less than 1 s^-1, which is ~ 10⁴ times slower than monomer exchange in bulk solutions. The actual exchange rate may be greater than observed in the present work due to transport phenomena. The rates of exchange are similar at concentrations above and below the critical micellar concentration. Adsorption is similarly rapid, but under some circumstances there is a small residue of surfactant that is slow to desorb. Desorption experiments utilizing KBr solutions of high and low ionic strength show that two thirds of each adsorbed micelle is held by hydrophobic association, and the other third is electrostatically bound. Adsorption, desorption, and exchange experiments at temperatures of 11&deg;C above and 8&deg;C below the Krafft temperature (14.4&deg;C) show similar kinetics. / Master of Science

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