Four beam-bond test specimens, two in accordance with RILEM TC-RC5 recommendation, labelled as RILEM and two based on a modified form of the ACI 208 beam-bond test method, labelled as Notched, were tested in four-point bending to investigate the bond stress distribution and values along the bar embedment length of a 15 𝑚𝑚 nominal diameter GFRP rebar. The beams experienced failure through the rupturing of the longitudinal GFRP tensile reinforcement. In addition, two Modified and ten Standard pullout specimens were tested using the same bar. The beam-bond and the Modified pullout specimens had embedment length of 600 𝑚𝑚 while the Standard pullout specimens had, in accordance with CSA S806, 60 𝑚𝑚 embedment, or four times the bar nominal diameter. The first Modified pullout specimen experienced concrete splitting failure and as a result, the second was lightly confined and failed by GFRP bar rupture. All ten Standard pullout specimens failed due to bar pullout. It was determined that the actual bond stress distribution as a function of the embedment length is practically parabolic and can be described by the derivative of a modified form of the logistic growth function used to approximate the strain distribution along the embedment length. Furthermore, the maximum bond stress location progressively moves from the loaded-end towards the unloaded-end as the bond continues to deteriorate with increasing GFRP stress levels. The development length recommendations by ACI 440.1 and to a lesser degree, CSA S806 and CSA S6 are quite conservative compared to that which is required. It is observed that pullout tests alone cannot provide sufficient knowledge regarding the bond behaviour of FRP reinforcement; consequently, the results of beam-bond testing are more appropriate. Standard pullout tests may be incorporated into quality assurance programs with the understanding that they cannot provide valuable information regarding bond stress distribution and required development length in real structural elements with large embedment lengths. In terms of the beam-bond test method, the RILEM TC-RC5 design recommendation appears to be superior since it eschews severe stress perturbation caused by incidence of flexural cracks at beam midspan. As a result, it produces stability in the terms of the data gathered from the strain gauges placed on the GFRP bar. This benefit outweighs the ease of constructability of the Notched beams as well as their resemblance to real beams. / Thesis / Master of Applied Science (MASc) / The force that bonds a reinforcing rod to concrete is determined using three test methods. Each method is recommended by some design standards, but it is unclear how the results of these tests compare to each other. To shed light on the issue, a 15 𝑚𝑚 fibre glass rod was tested using three well-known test methods. It was discovered that two of the methods give results that are reasonably close while the third gives variable results that generally do not agree with the results of the other two. It was also discovered that the required embedment length recommended for such a bar by design codes and standards are relatively excessive because they underestimate the actual bond strength of the rod. Since sometimes it may be difficult to provide such long length in practice, it is recommended that the code requirements be revisited.

Yes / UV/vis absorption titrations have been used to investigate the formation of H-bonded complexes between anionic H-bond acceptors (HBAs) and neutral H-bond donors (HBDs) in organic solvents. Complexes formed by three different HBDs with 15 different anions were studied in chloroform and in acetonitrile. The data were used to determine self-consistent HBA parameters (β) for chloride, bromide, iodide, phosphate diester, acetate, benzoate, perrhenate, nitrate, triflimide, perchlorate, hexafluorophosphate, hydrogen sulfate, methyl sulfonate, triflate, and perfluorobutyl sulfonate. The results demonstrate the transferability of H-bond parameters for anions between different solvents and different HBD partners, allowing reliable prediction of anion recognition properties in other scenarios. Carboxylates are the strongest HBAs studied, with β parameters (≈ 15) that are significantly higher than those of neutral organic HBAs, and the non-coordinating anion hexafluorophosphate is the weakest acceptor, with a β parameter comparable to that of pyridine. The effects of ion pairing with the counter-cation were found to be negligible, provided small polar cations were avoided in the less polar solvent (chloroform). There is no correlation between the H-bonding properties of the anions and the pKa values of the conjugate acids. / Engineering and Physical Sciences Research Council (EPSRC).

The main focus of this thesis is on the ring conformations of carbohydrate molecules; how the conformational equilibria and the rates of the associated interconversions are affected by the molecular constitution and their surroundings. The conformational equilibria of a group of amine linked pseudodisaccharides, designed as potential glycosidase inhibitors, comprising α-D-altrosides are described in Chapter 3. The OS2 conformation was largely populated, and the ring conformation was found to depend on the charge of the amine functionality. The conformations of β-D-xylopyranoside derivatives with naphthyl-based aglycones, which are potential anti-cancer agents, are described in chapter 4. Solvent dependent flexibility was observed. Intramolecular hydrogen bonds were concluded to be involved in the stabilization of 1C4 conformers in non-hydrogen bonding solvents of low polarity. Chapter 5 describes the first measurements of the conformational exchange rates of mannuronic acid ester derivatives between the 4C1 and 1C4 conformations, through DNMR measurements. The relative reactivity of glycosyl triflates as electrophiles in glycosylation reactions were investigated with NMR-based competition experiments. In Chapter 6, investigations of ruthenium-catalyzed epimerizations of the allylic alcohols of glycal derivatives, and stereoselective synthesis of esters through a DYKAT protocol, are described. The kinetics of the epimerizations were elaborated through different NMR-spectroscopic methods. Chapter 7 describes additions of NMR chemical shift data of mono- and oligosaccharides to database of the computer program CASPER, and applications thereof. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 4: Submitted. Paper 5: Manuscript.</p>

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Pulsed-beam Fourier transform microwave spectroscopy (PBFTMS) was used to determine the rotational structure of N-hydroxypyridine-2(1H)-thione. PBFTMS was also used to determine the rotational structure of a hydrogen dimer between propiolic acid and formic acid. Rotational constants and quadrupole coupling constants were determined. Calculations (MP2/DFT) were utilized in predicting the isotopic structures. Isotopic data (D, and ¹³C) and normal isotopomers collected were used in establishing of key structural parameters such as bond length and bond angles.

An integrated graph-theoretic and geometric approach to the analysis of aqueous solvation of atomic ions is presented. This analysis makes use of a novel data-mining tool, moleculaRnetworks, to process data from molecular dynamics simulations. The workings and structure of this tool are discussed, along with the development and testing of its PageRank algorithm-based rapid solvation polyhedra classifier. The ability to classify instantaneous solvation polyhedra enables a finely detailed understanding of shell structure-behavior relationships, as water molecules simultaneously rearrange about ions, exchange with the bulk, and rearrange their hydrogen-bond network. The application of the tool to cation systems, including lithium, sodium, potassium, magnesium, calcium, and lanthanum, yields new insight into the mechanisms of water exchange about these ions. It is shown that in order for exchange events to occur, the solvation shell must "preorganize" to admit or expel a molecule of water: this preorganization is reflected in the mechanistic preference for each ion. The application of the tool to anion systems, including fluoride, chloride, and bromide, reveals that these ions have an extended effect on the reorientation ability of water molecules beyond their first solvation shell. Finally, when both ions are present, as in the potential of mean force simulation between lanthanum and chloride, structural rearrangements can be seen as the ions break through the barrier to form the contact ion pair. Taken together, these results show the utility of the moleculaRnetworks tool in broadening our understanding of aqueous ion solvation.

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