The plant cell wall contains significant quantities of renewable polymers in the form of cellulose, hemicellulose, and lignin. These three renewable polymers have the potential to complement or replace synthetic polymers in a variety of applications. Rapidly determining the quantities of these polysaccharides in lignocellulosic biomass is important yet difficult since plant biomass is recalcitrant and highly variable in composition. Part of this contribution outlines a novel compositional analysis protocol using infrared spectroscopy and multivariate regression techniques that is rapid and inexpensive. Multivariate regression models based on calibration mixtures can be used to discern between populations of lignocellulosic biomass or to predict cellulose, hemicellulose, and lignin quantities. Thus, the compositional analysis step can be expedited so that other processes, like fractionation of the lignocellulose polymers, can be tuned accordingly to maximize the value of the final product. Hybrid materials were also generated using a variety of polymerization techniques and post-polymerization modifications. A novel controlled/living radical polymerization initiator was synthesized (2-bromo-2-methylpropane hydrazide) containing a hydrazide functionality that was covalently linked to the reducing-end of dextran. Despite the rapid coupling of the hydrazide- based initiator to the reducing-end of dextran, the instability of the alkyl bromide bond resulted in several unsuccessful attempts at Cu(0)-mediated controlled/living radical polymerization. Recommendations were given to improve the stability of this compound; however, an alternative approach to synthesizing hybrid copolymers was also investigated in parallel. Hyperbranched polymers were synthesized using commercially available vinyl and divinyl monomers in the presence of a cobalt(II) complex that enabled control over the size, architecture, and mol% of pendant vinyl groups amenable to post-polymerization modification. Modifying the ratio of divinyl monomer to cobalt(II) complex provided a series of hyperbranched polymers with variable morphology and mol% pendant vinyl groups. The pendant vinyl bonds were subsequently converted to amines via thiol additions with cysteamine. These amine functionalized hyperbranched polymers were then used in a subsequent reductive amination reaction with the reducing-end of dextran to produce the amphiphilic core-shell copolymer poly(methyl methacrylate-co-ethylene glycol dimethacrylate)-b-dextran. These amphiphilic copolymers mimicked the colloidal behaviour of conventional block copolymer micelles without requiring difficult syntheses or tedious self-assembly steps. / Thesis (Master, Chemical Engineering) -- Queen's University, 2012-02-28 11:20:01.568

No description available.

Copper-organonitrogen complexes are studied by threshold photoionization and zero electron kinetic energy photoelectron spectroscopy. These complexes are prepared in pulsed laser vaporization supersonic molecular beams. Adiabatic ionization energies of the neutral species and vibrational frequencies of the neutral and ionic complexes were measured. Metal-ligand bond dissociation energies were obtained from the theoretical calculations or the experiments. More importantly, by combining the spectroscopic measurements, quantum chemical calculations, and spectral simulations, metal-ligand bonding structures are determined for copper complexes of diamines, pyridine, diazines, aminopyridines, polypyridines, and imidazole. The Cu-ethylenediamine, -(1,3-propanediamine), and -(1,4-butenediamine) complexes have been determined to be in a hydrogen-bond stabilized monodentate configuration. However, Cu atom binds to both two nitrogens in the methyl-substituted ethylenediamines. The change of the Cu binding from the monodentate to the bidentate mode arises from the competition between copper coordination and hydrogen bonding. Although pyridine, diazines, and imidazole molecules can function as a s-donor through the nitrogen atom, a p-acceptor or p-donor through six-membered or five-membered aromatic ring, only the s bonding mode is predicted by the theory and identified by the ZEKE spectroscopy. For aminopyridine molecules, s bonding through the sp2 or sp3 hybrid electron lone pair and p bonding through the pyridine ring are possible. Yet, the s bonding through the sp2 electron donation is calculated to be the strongest, and the Cuaminopyridine complexes formed by such bonding mechanism are identified by the experiments. Moreover, monodentate Cu-(4,4'-bipyridine), bidentate Cu-(2,2'-bipyridine) and Cu-(1,10-phenanthroline), and tridentate Cu-(2,2':6',2?-terpyridine) are established to be the most stable structure and are observed by experiments. It is surprising to find that the tridendate planar structure of Cu-(2,2':6',2?-terpyridine) changes to a twisted Cs structure upon ionization.

No description available.

The West Ansil deposit was the first Cu discovery in 25 years in the Noranda Central Camp. It has a combined indicated and inferred resource of ~1.2 Mt. Grades for the indicated resource are 3.4% Cu, 0.4% Zn, 1.4 g/t Au and 9.2 g/t Ag. The bulk of the resource is located in three massive sulphide lenses (Upper, Middle and Lower) that are entirely within the Rusty Ridge Formation above the Lewis exhalite. The mineralization in all three ore lenses consists of massive pyrrhotite + chalcopyrite + magnetite. Semi-massive sphalerite is restricted to the upper and lower parts of the Middle lens. Massive magnetite occurs at the center of the Upper and Middle lenses, where it replaces massive pyrrhotite. A striking feature of West Ansil is the presence of abundant colloform and nodular pyrite (+marcasite) in the massive sulphides. Late-stage replacement of massive pyrrhotite by colloform pyrite and marcasite, occurs mostly along the upper and lower contacts of the lenses.

Homogenization of alloying elements is desired during sintering of powder metallurgy components. The redistribution processes such as penetration of liquid phase into the interparticle/grain boundaries of solid particles and subsequent solid-state  diffusion of alloy element(s) in the base powder, are important for the effective homogenization of alloy element(s) during liquid phase sintering of the mixed powders. The aim of this study is to increase the understanding of alloy element redistribution processes and their effect on the dimensional properties of the compact by means of numerical and experimental techniques. The phase field model coupled with Navier-Stokes equations is used for the simulations of dynamic wetting of millimeter- and micrometer-sized metal drops and liquid phase penetration into interparticle boundaries. The simulations of solid particle rearrangement under the action of capillary forces exerted by the liquid phase are carried out by using the equilibrium equation for a linear elastic material. Thermodynamic and kinetic calculations are performed to predict the phase diagram and the diffusion distances respectively. The test materials used for the experimental studies are three different powder mixes; Fe-2%Cu, Fe-2%Cu-0.5%C, and Fe-2%(Cu-2%Ni-1.5%Si)-0.5%C. Light optical microscopy, energy dispersive X-ray spectroscopy and dilatometry are used to study the microstructure, kinetics of the liquid phase penetration, solid-state diffusion of the Cu, and the dimensional changes during sintering. The wetting simulations are verified by matching the spreading experiments of millimeter-sized metal drops and it is observed that wetting kinetics is much faster for a micrometer-sized drop compared to the millimeter-sized drop. The simulations predicted the liquid phase penetration kinetics and the motion of solid particles during the primary rearrangement stage of liquid phase sintering in agreement with the analytical model. Microscopy revealed that the C addition delayed the penetration of the Cu rich liquid phase into interparticle/grain boundaries of Fe particles, especially into the grain boundaries of large Fe particles, and consequently the Cu diffusion in Fe is also delayed. We propose that the relatively lower magnitude of the sudden volumetric expansion in the master alloy system could be due to the continuous melting of liquid forming master alloy particles. / <p>QC 20140515</p>

The limitations of the conventional Cu/low-k interconnect technology for use in future ultra-scaled integrated circuits down to 7 nm in the year 2020 are investigated from the power/performance point of view. Compact models are used to demonstrate the impacts of various interconnect process parameters, for instance, the interconnect barrier/liner bilayer thickness and aspect ratio, on the design and optimization of a multilevel interconnect network. A framework to perform a sensitivity analysis for the circuit behavior to interconnect process parameters is created for future FinFET CMOS technology nodes. Multiple predictive cell libraries down to the 7‒nm technology node are constructed to enable early investigation of the electronic chip performance using commercial electronic design automation (EDA) tools with real chip information. Findings indicated new opportunities that arise for emerging novel interconnect technologies from the materials and process perspectives. These opportunities are evaluated based on potential benefits that are quantified with rigorous circuit-level simulations and requirements for key parameters are underlined. The impacts of various emerging interconnect technologies on the performances of emerging devices are analyzed to quantify the realistic circuit- and system-level benefits that these new switches can offer.

The diesel engine is growing in popularity due to its energy efficiency and solving the emissions issues associated with diesel engine exhaust would clear the way for further growth. The key pollutants are NOx, particulate matter and unburned hydrocarbons. Selective catalytic reduction (SCR) catalysis is likely the best choice for NOx control. In SCR, NH3 selectively reacts with NOx to form N2 – the selectivity refers to NH3 reacting with NOx instead of the abundant O2. Urea is used as the NH3 source, being injected into the exhaust as an aqueous solution where the urea decomposes and NH3 is generated. Spatial resolution characterization techniques have been gaining attention in the catalysis field because of the higher level of information provided. In this thesis, a new spatial resolution technique, called SpaciFTIR (spatially-resolved, capillary-inlet Fourier transform infra-red spectroscopy), was developed, which overcomes the interference of water in the detection of NH3 in an earlier developed technique, SpaciMS (spatially-resolved, capillary-inlet mass spectrometry). With the new test method, three SCR topics were addressed. First, the three key SCR reactions were spatially resolved. These are the standard SCR reaction (2NO + 2NH3 + 1/2O2 = 2N2 + 3H2O), the fast SCR reaction (NO + NO2 + 2NH3 = 2N2 + 3H2O), and NO2-SCR, (6NO2 + 8NH3 = 7N2 + 12H2O). Results show that in the presence of NO2, but at a NO2/NOx ratio < 0.5, the fast SCR reaction proceeds followed by the standard SCR reaction, i.e. in series. If the NO2/NOx ratio exceeds 0.5, the NO2-SCR and fast SCR reactions occur in parallel. Compared to the standard integral test method, this spatial resolution technique clearly showed such trends. Secondly, the spatial resolution technique was used to characterize the effects of thermal aging on catalyst performance. It was found that for a highly aged catalyst, there was a radial activity profile due to an inhomogeneous temperature distribution in the process of aging. Aging effects on various key SCR reactions, i.e. NO oxidation, NH3 oxidation, and the reduction reactions, were studied. Last but not least, for the purpose of passive SCR system development, transient NH3 storage profiles along the monolith channel were measured with SpaciFTIR. Passive SCR is a system where the NH3 is generated on an upstream catalyst, such as a three-way catalyst or lean-NOx trap, instead of via urea injection. In such a system, NH3 is therefore not constantly being fed to the SCR catalyst, but “arrives” in pulses. Factors such temperature, NH3 concentration, pulsing time, flow rate and thermal aging were investigated. For the first time, NH3 migration was observed and its effect on SCR reactions along the length of catalyst was studied.

In this study, a cold worked tool steel and a low carbon steel ( St 37 ), which were joined by brazing, were subjected to impact and shear loading. The end product is used as paper cutting blades in the industry. Effects of different brazing filler metals on the delamination of the blades under impact loading and on the impact toughness of the blades were studied. The target is to achieve higher impact toughness values without delamination. Impact toughness of the steels, joined by Cu, CuNi and BNi brazing filler metals and separation of brazed surfaces under shear loading were studied. The microstructures that were formed as a result of each application were studied by scanning electron microscopy and x-ray diffraction. The results indicate that brittle intermetallic compounds are formed in BNi brazing filler metal application. It is observed that CuNi alloy with 24% wt Ni form stronger bonds with the base metals than pure Cu and 10% wt Ni CuNi alloy.

No description available.