An experimental investigation has been carried out into the mixing of a row of jets injected into a confined cross-flow. Measurements were made on a fully annular test facility, the geometry of the rig simulating that found in the dilution zone of a gas turbine combustion chamber. A small temperature difference of 44°C between the cross-flow and dilution fluid allowed the mixing characteristics to be assessed, with hot jets being injected into a relatively cold cross-flow at a jet to cross-flow momentum flux ratio of 4.0. The investigation concentrated on differences in the mixing of individual dilution jets, as indicated by the regularity of the temperature patterns around the cross-flow annulus. Despite the uniform conditions approaching the dilution holes there were significant differences in the temperature patterns produced by the dilution jets around the annulus.

Micro-devices are developed for uses in targeted drug delivery and microscale manipulation. Here we numerically and analytically study two promising devices in early stages of development. Firstly, we study Armoured Microbubbles (AMBs) which can self-propel as artificial microswimmers or facilitate microfluidic mixing in a channel when held stationary on a wall. Secondly, we study an artificial cilium, which due to its unique design, when placed in an array, easily produces a metachronal wave for fluid transportation. The Armoured Microbubble was designed by our experimental collaborators (group of Philippe Marmottant, University Grenoble Alpes) and consists of a partial hollow sphere, inside which a bubble is caught. Under ultrasound the bubble oscillates, generating a streaming flow in the surrounding fluid and producing a net force. Motivated by the AMB but considering initially a general setup, using matched asymptotic expansions we calculate the streaming flow around a spherical body undergoing arbitrary, but known, small-amplitude surface shape oscillations. We then specialise back to the AMB and consider its excitation under ultrasound, using a potential flow model with mixed boundary conditions, to identify the resonant frequencies and mode shapes, including the dependence of the resonance on the AMB shape parameters. Returning to our general streaming model, we applied the mixed boundary conditions directly to this model, calculating the streaming around the AMB, in good agreement with experiments. Using hydrodynamic images and linear superposition, this model was extended to incorporate one wall, and AMB compounds. We then study the streaming flows generated by arrays of AMBs in confined channels, by modelling each AMB as its leading order behaviour (with corrections where required) and superposing the individual flow fields of all the AMBs. We identified the importance of two confining walls on the streaming flow around the array, and compared these flows to experiments in five cases. Motivated by this setup, we theoretically considered the extension of a two fluid interface passing through an AMB array to quickly identify good AMB arrays for mixing. We then studied the second artificial micro-device: an artificial cilium. Tsumori et. al. produced a cilium of PDMS containing aligned ferromagnetic filings, which beat under a rotating magnetic field. We modelled a similar cilium but assumed paramagnetic filings, using a force model balancing elastic, magnetic and hydrodynamic forces identifying the cilium beat pattern. This agreed with our equilibrium model and asymptotic analysis. We then successfully identified that the cilium applies the most force to the surrounding fluid at an intermediate value of the two dimensionless numbers quantifying the dynamics.

The modern era of particle physics is driven by experimental anomalies. Experimental efforts have become increasingly diverse and are producing enormous volumes of data. In such a highly data-driven scientific environment theoretical models are necessary to understand this data and to help inform the development of new experimental approaches. In this dissertation I present two significant contributions to this effort relevant to the energy, intensity, and cosmic frontiers of modern particle physics research. Part 1 of this dissertation discusses methods to understand modern dark matter direct detection results. In particular I present an analysis under the hypothesis of inelastic dark matter, which supposes that dark matter must scatter inelastically, i.e. that it must gain or loose mass during a collision with atomic nuclei. This hypothesis is attractive because it can alleviate otherwise contradictory results from a number of dark matter detection facilities. The main conclusion of this work is a presentation of the analytical tools, along with a mathematica package that can be used to run the analysis, and the discovery that there are regions of inelastic dark matter parameter space which are consistent with all current experimental results, and constraints. Part 2 of this dissertation discusses a phenomenon of modern interest called kinetic mixing which allows particles from the standard model to spontaneously transform into particles which experience a new, as of yet undiscovered, force. This phenomenon is relatively common and well motivated theoretically and has motivated significant experimental effort. In this work, I present an analysis of a general case of kinetic mixing, called nonabelian kinetic mixing. This work shows that, In general, kinetic mixing predicts the existence of a new particle and that, under certain conditions, this particle could be detected at modern particle colliders. Furthermore, the mass of this particle is related to the strength of kinetic mixing. This relationship suggests novel ways to constrain kinetic mixing parameter space, and if observed would provide a very striking indication that such a model is realized in nature.

CeiKNSBN is a new photorefractive material in the KNSBN family, which has some advantages compared to other crystals. Based on two-wave mixing theory, different methods are used to investigate the photorefractvie properties of the Ce:KNSBN crystal. Most parameters of the CeiKNSBN crystal are in the same orders with those of Cu:KNSBN crystal. The diffraction efficiency from the CeiKNSBN crystal is affected by the applied electric field. The applied field increases the response rate of the grating formation and enhances the diffraction efficiency. There exists an optimum applied field and grating spacing related to the maximum diffraction efficiency, and the history of applied field influences the value of diffraction efficiency. Fanning loss and thermal effects should be considered in the diffraction theory for the CeiKNSBN crystal. The phase conjugate properties of the CeiKNSBN crystal are demonstrated in the four-wave mixing configuration and in the SPPC CAT conjugator. The experimental results agree with the analytical solution under some conditions. The He-Ne laser generates higher SPPC in the CeiKNSBN crystal than that by the argon-ion laser. The Doppler frequency detuning technique is first, to our knowledge, applied in the SPPC CAT configuration. The SPPC reflectivity is enhanced and the uniformity of the reflectivity is improved by this technique.

This thesis presents an investigation into the dynamics of vortex rings impacting a sharply-stratified density interface. This problem has a long history and is important for understanding how individual eddies in stratified turbulence mix the density field. We tackle this problem using a combination of experimental, numerical and modelling techniques to understand the flow instability and subsequent mixing induced by the impinging vortex ring. Our findings demonstrate that there exists a critical Richardson number, corresponding to a mixing transition, beyond which the mixing efficiency is constant. Using a novel Stereo Particle Image Velocimetry (Stereo-PIV) technique, we analyze a series of vortex ring experiments. By amalgamating an ensemble of these experiments, we measure the full, time-resolved, three-dimensional velocity field of the vortex-ring interaction. These measurements capture the instability that is produced on the baroclinically generated vorticity field. This instability is identified as a Crow-like instability. At low Richardson numbers, the timescale of the interface rebound is faster than that of the instability. As a result, there exists a critical Richardson number below which the Crow-like instability will not have sufficient time to grow to large amplitude. By generating a large number of vortex-ring interactions, we measure the incremental change to the stratification. After an initialization period, there is strong evidence to suggest that the mixing due to each vortex ring becomes constant over a moderate range of Richardson numbers. We suggest that the mixing efficiency of the vortex rings does drop at low Richardson numbers (below unity) in agreement with the analysis of the Stereo-PIV measurements. A model of the system accurately predicts the dependence of the mixing rate on the Richardson number. Based upon our study of the vortex-ring system, we construct a one-dimensional turbulence model that includes the energy advection from the vortex rings. This model is validated with both physical experiments and numerical simulations of repeated vortex-ring generations. The constant mixing efficiency regime is recovered in all three methodologies. Through examining the detailed dynamics of the flow, this work suggests that there exists a critical Richardson number corresponding to a transition between mixing regimes, and that this critical Richardson number is a result of the growth of a Crow-like instability. We have highlighted how to improve current mixing-models to capture this physics. New avenues of future research are currently underway to study the mixing produced by a stratified mixing-box experiment in light of these new developments.

Sistemas multifásicos reativos, como as argamassas, vêm sendo bastante estudados e explorados das mais diversas formas ao longo dos anos. A mistura é uma das etapas do processamento (mistura, transporte e aplicação) desses sistemas que, devido à aparente simplicidade operacional tem sido de certa forma negligenciada. A qualidade da mistura exerce influência direta no comportamento reológico e nas propriedades no estado endurecido. Nesse contexto, os objetivos da pesquisa consistem em avaliar a influência de parâmetros que interferem no comportamento de mistura (tempo, taxa de adição de água e velocidade de mistura do equipamento), no intuito de entender o fenômeno físico envolvido, sugerindo técnicas de análise para estudá-los e propor procedimentos (sequência de introdução dos materiais) mais adequados para a mistura de argamassas em laboratório. O trabalho de pesquisa compreende duas etapas. A primeira trata da avaliação dos parâmetros que influenciam a mistura de argamassas (cimento, cal, filer e areia) com e sem aditivo dispersante (policarboxilato de sódio) e, estabelece técnicas de análise da curva de mistura, obtida no reômetro rotacional tipo planetário desenvolvido na POLI-USP. A segunda etapa estuda diferentes procedimentos de mistura de argamassas em laboratório, na Hobart, e os compara com o procedimento da ABNT NBR13276/2005. No estado fresco emprega-se a reometria rotacional (curva de mistura + ciclos de cisalhamento) e squeeze-flow (na segunda etapa do trabalho) para avaliação do comportamento reológico. No estado endurecido, as propriedades mecânicas são verificadas por meio de resistência à tração por compressão diametral, módulo de elasticidade dinâmico e porosidade. Os resultados obtidos na primeira etapa, indicam que a técnica empregada na análise das curvas mostra ser apropriada para avaliar o fenômeno físico envolvido na dispersão e homogeneização das partículas do sistema durante a mistura. Na segunda etapa, o estudo de diferentes procedimentos de mistura em laboratório, aponta que introduzir o líquido nos materiais sólidos, nas condições analisadas, tende a produzir sistemas mais fluidos. Dependendo da composição dos sistemas, estes podem ser mais ou menos suscetíveis ao processo de mistura. E, por fim, no estado endurecido, as propriedades avaliadas indicam que um processo de mistura adequado conduz a resultados satisfatórios no material endurecido, com redução da porosidade e melhor desempenho do produto final. / Multiphase reactive systems, such as mortars, have been extensively studied in many different ways over the years. The mixture is one of the processing steps (mixing, transport, application) of these systems that due to its apparent operational simplicity, has been somewhat neglected. The quality of the mixing process has a direct influence on the rheological behavior and on the properties in the hardened state. In this context, the objectives of the research are to assess the influence of experimental parameters that affect the mixing behavior (time, water addition rate and rotation speed) in order to understand the physical phenomena involved, and to develop analysis methodology and propose procedures (sequence of mixing) best suited for mixing mortar in the laboratory. The research comprises two steps; the first part is the evaluation of the influence of experimental parameters on mixing behavior of mortars (cement, lime, filler, sand) with and without additive (sodium polycarboxylate) and the establishment of a methodology to analyze the mixing curve obtained in planetary rotational rheometer developed on POLI-USP, and the second stage studies different procedures for mixing mortars in laboratory, on Hobart, and compares them with the current ABNT NBR13276/2005 standard procedure. In the fresh state rotational rheometer (mixing curve + shear cycles) and squeeze-flow (in the second stage of research) are used for rheological characterization, while mechanical properties were verified by splitting tensile strength, dynamic modulus of elasticity and porosity. The results obtained in the first step indicates that the technique employed for the analysis of the curves is suitable for evaluating the physical phenomena involved in the dispersion and homogenization of the particles during mixing. In the second step, the study of different mixing procedures in the laboratory indicates that introducing the water in the solids tends to produce more fluid systems. The mixing behavior of the systems depends on their mix design (composition). Finally, in the hardened state, properties evaluated indicated that a suitable mixing process leads to satisfactory results with reduced porosity and better final performance of the products.

Cutter Soil Mixing (CSM) is a recently developed deep mixing technique that has grown to include the treatment of sandy and silty soils. This study seeks to investigate the influence of (i) sand-silt ratio, (ii) cement content, (iii) water content and (iv) time on the unconfined compressive strength of saturated cement-treated soil specimens. A new test device and method of specimen reconstitution were conceived in order to obtain a saturated mix of soil and cement. A comparison of results show strength increases non-linearly to decreasing total water-cement ratio, and that this trend is largely independent of sand-silt ratio. Furthermore, strength increases non-linearly with time and is independent of sand-silt ratio. Lastly, it is recommended that the strength be correlated with total water-cement ratio rather than cement content, in order to improve data reporting and provide design guidance to engineering practice. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate

The very existence of intra-word codeswitching—of the type [w ML1 + ML2]; *[eat]eng + [-iendo]Spanish —has long been a point of contention in the language mixing literature (Poplack, 1980; Myers-Scotton, 1992; MacSwan, 2005). However, recent work by Alexiadou et al (2015) and Grimstad, Lohndal & Afarli (2014) has documented a number of empirical examples of such codeswitching in an American community of Heritage Norwegian-English speakers—crucially, in these examples, the lexical elements are English lexical roots and produced using English phonological rules but the suffix (i.e. morphology) attached to the lexical items is syntactically Norwegian—a clear and unambiguous example of intra-word codeswitching. These data will be the focus of investigation into intra-word codeswitching. MacSwan (2005) has argued that intra-word codeswitching is prohibited due to the inability of the human computational system to merge hierarchically ordered phonological systems from two or more languages; a prohibition characterized in his PF Disjunction Theorem. More recently, Alexiadou et al., (2015); Grimstad, Lohndal & Afarli, (2014) have exploited a model of Distributed Morphology to challenge the PF disjunction theorem and the ban on intra-word codeswitching it entails. A central goal of this thesis will be to compare, contrast and evaluate these two models of language mixing. It will be argued that this prohibition of intra-word language mixing may be overcome by appealing to a cognitive processes perspective (Sharwood-Smith & Truscott, 2014). A MOGUL processing prospective (Sharwood-Smith & Truscott, 2014) will be used to build upon previous approaches to language mixing in order to account for intra-word codeswitching. The modular architecture adopted by MOGUL allows for a molecular view of a lexical item; each module (i.e. phonological module, syntax module, conceptual module) produces a representation for a given form which is then interfaced to neighboring modules; the result is a chain of representations (i.e. PS + SS + CS) which constitutes a lexical item. Additionally, MOGUL incorporates several extra-linguistic cognitive mechanisms which play a role in language mixing. Of particular interest are the notions of goals and cognitive context. Following Sharwood-smith & Truscott (2016), goals are the central motivators for speech and action while cognitive context is taken to be the mentally internalized representation of an individual’s current environment (Sharwood-Smith & Truscott, 2014) as well as representing various intentions, perspectives, opinions, etc., an individual has regarding their environment (Van Dijk, 1997). To situate intra-word codeswitching into a MOGUL framework, much of MacSwan’s Minimalist account will be adopted, (i.e. codeswitching is accounted for via the union of grammar X and grammar Y; formally: {Gx ᴜ Gy}) while rejecting the PF Disjunction Theorem and, instead, adopting elements of Distributed Morphology (i.e. late insertion). It will be argued that cognitive context configures various executive control process (i.e. bilingual mode) to allow for the union of phonological systems between Lx and Ly. This analysis builds upon a larger body of language mixing research by synthesizing a Minimalist account of codeswitching with a cognitive processing framework to account for intra-word codeswitching; the MOGUL framework allows for these disparate elements to be synthesized. / Graduate

Consumer- and pharmaceutical-based products are a major component of the chemical industry. In the personal care industry, formulations often consist of a mixture of surfactants and fatty alcohols. The addition of surfactants aids the stability of the formulation. The formulated product microstructure depends upon the preparation conditions as well as the ingredients. Controlling which microstructures form during the production of a formulated product is important as different microstructures can have wildly different physical properties, making some far more favourable than others. This thesis examines several of the processes undertaken in the manufacture of formulated products. The dissolution of a surfactant in a bulk water phase is examined. This is examined in a number of ways; firstly, the dissolution times of the surfactants are measured using electrical resistance tomography. It is found that the dissolution time varies with the agitation rate, agitator size, and addition method. The dissolution is also examined using dissipative particle dynamics to gain insight into the dissolution on a molecular scale. It is found that the surfactant breaks into wormlike micelles on dissolution. If an oil is added to the initial bulk then the dissolution process is modified so that long cylinders are produced with some spherical micelles. Finally, the break-up rate is predicted using a breakage model based on the agitator shear rate and a network-of-zones model. This produces good results. The production and post-shear processing of a sample formulated product, hair conditioner, is examined. Firstly, the mixing in a vessel is examined with electrical resistance tomography. Problems are encountered when the production method involves the use of distilled water as the conductivity is very low; however, the mixing time of the final product in the vessel can be determined. It is also shown that the majority of the structural changes in the post-shearing process are caused by the in-line rotor-stator mixer. The viscosity of the product increases in a linear fashion with the shear rate, while the conductivity increases as a function of the shear rate and the recycle rate. This allows the monitoring of the post-shearing process to be carried out using electrical resistance tomography. This thesis also looks at the possibility of producing a multiple frequency electrical resistance tomography device to monitor formulated product production; however, it has been shown that the conductivity does not vary with the voltage frequency over a usable range. This meant that no further effort was put into developing this, as it gave no advantage over the traditional single frequency technique. Nevertheless, important advances towards better understanding of mixing processes resulted due to the investigations carried out.

This thesis presents several studies of data collected at the LHCb detector during its first two years of operation. A detector upgrade study is first presented, using simulated events at an increased luminosity. A second study involves radiation damage to the silicon sensors of the LHCb Vertex Locator. During 2010 and 2011the silicon sensors were exposed to a range of fluences, with sensors in the mostactive regions exposed to fluences of up to approximately 45x10^12 1MeV neutron equivalent (1MeV neq). The first observation of n+-on-n sensor type inversion at the Large Hadron Collider is reported, occurring at a fluence of around (10-15)x10^12 of 1MeV neq. The effective depletion voltages of the only n+-on-p sensors in use at the Large Hadron Collider have also been studied, with decreases of around 25V observed after initial irradiation. Following this, the effective depletion voltage inn+-on-p type sensors is observed to increase at a comparable rate to type inverted n+-on-n type sensors. A reduction in the charge collection efficiency due to an unexpected effect involving the sensor readout lines is also observed. A third study relates to CP violation in neutral B-meson mixing, by the measurement of the flavour-specific asymmetry. In the Standard Model, CP violation from this source is expected to be of order 10^-4. Any measured enhancement of this would be a strong indication of new physics. The DØ collaboration has measured the flavour specific asymmetry from B0 and B0s mixing, and found it to be inconsistent with the Standard Model at a confidence level of 3.9 standard deviations, thus motivating an independent measurement from the LHCb experiment. Using the full 2011 LHCb dataset, corresponding to 1.0 fb^-1 of recorded luminosity, the B0s-meson component of the flavour-specific asymmetry is measured to be afs_s = (-0.12 +/- 0.48 +/- 0.34)%, where the first uncertainty is statistical and the second is systematic. This is the single most accurate measurement of afs_s, and is consistent with both the DØ measurement and the Standard Model prediction.