This thesis is a study of the theory and phenomenology of trans-Planckian black holes, in TeV gravity extra-dimensional theories. The introduction starts with the motivation for this beyond the Standard Model scenario (chapter 1), a summary of the theoretical tools to formulate the theory, and a summary of the best bounds from experiment (chapter 2). In chapter 3, after setting up some notation and describing well known solutions in 4 + n-dimensional general relativity, we construct an approximate effective background for a brane charged rotating higher-dimensional black hole. This is achieved by solving Maxwell's equations perturbatively on the brane to obtain the electromagnetic field. A brief study of the effect of rotation on the absorption of classical particles is also provided. Chapter 4 is a review of methods to model black hole production focusing on the trapped surface method. A model for the mass and angular momentum loss into gravitational radiation is described. A detailed study of the effects of particle mass and charge, for fermions and scalars on the effective brane charged background, is presented in chapters 5 and 6. After coupling the fields to the background, the separated radial wave equations for both perturbations are obtained (chapter 5) and they are integrated using a detailed numerical method as well as analytic approximations (chapter 6). Similarly, a method is described to obtain high accuracy angular functions based on series expansions. We conclude the theoretical study by evaluating the Hawking spectra for various combinations of spin, mass, charge and rotation parameters, and discuss them comparatively. The last part of the thesis is on the implementation of the theoretical results in the new CHARYBDIS2 Monte Carlo simulation of black hole production and decay (chapter 7), and on the analysis of the phenomenological consequences (chapter 8). The main new features implemented in CHARYBDIS2 are: a full treatment of the spin-down phase using the angular and energy distributions of the associated Hawking radiation; an improved model for energy and angular momentum loss in the production process, and a wider range of options for the Planck-scale termination of the decay. The main conclusions of this thesis and an outlook on future directions are summarised in the final chapter.

The effect of particle size distribution (PSD) on the performance of a fluidized bed reactor was investigated using the ozone decomposition reaction, combined with the study of hydrodynamics, for fresh and spent fluid cracking catalysts, each having three particle size distributions - wide, narrow and bimodal - all with nearly the same mean diameter (60 µm), the same particle density and the same BET surface area. The superficial gas velocity was varied from 0.1 to 1.8 m/s to include the bubbling, slugging, turbulent and fast fluidization regimes. The catalytic rate constant, based on the volume of the particles, ranged from 2 to10 s⁻¹, while the static bed height was varied from 0.15 m to 1 m. Four different multi-orifice gas distributors with different hole diameters (2.2 to 5.1 mm) and hole numbers (4 and 21) were also tested to evaluate the influence of gas distributor on the performance of fluidized bed reactors. The particle size distribution was found to play a larger role at higher gas velocities than at lower velocities. At low gas velocities (Uf ≤ 0.2 m/s), the reaction conversion was not greatly affected by the PSD. However, with an increase in gas velocity the PSD effect became larger. The wide size distribution gave the highest reactor efficiency, defined as the ratio of the volume of catalyst required in a plug flow reactor to that required in the fluidized bed reactor to achieve the same conversion, while the narrow blend gave the lowest. The differences are not solely a function of the "fines content". The influence of particle size distribution on the hydrodynamics of fluidization was evaluated by measuring particle concentrations in voids, bubble sizes, and dense phase expansion. When the superficial gas velocity exceeded 0.1 m/s, the bed with the wide size distribution usually gave the highest particle concentration inside the voids, the smallest bubble size and the greatest dense phase expansion at the same operating conditions. There is evidence that there is a greater proportion of "fines" present in the voids than in the overall particle size distribution. This has been explained in terms of the throughflow velocity inside bubbles being of the same order as the terminal velocity of typical "fines", causing these particles to spend longer periods of time inside the voids. The effect of the PSD on the fluidization regime and its transitions was determined by measuring pressure fluctuations along the column. The earliest transition from bubbling or slugging to turbulent fluidization occurred in the bed of wide size distribution, while the latest corresponded to the narrow PSD. For particles of wide size distribution, higher conversion was achieved for the turbulent and fast fluidization regimes than for the bubbling fluidization regime under otherwise identical conditions, while for particles of narrow size distribution, the dependence of conversion on regime was small. Hence, for reactors of wide PSD, the performance can be improved significantly by operating in the turbulent or fast fluidization regime, while for particles of narrow size distribution, the benefit of operating at high gas velocity is slight at best. The PSD influence should be considered in modelling fluidized bed reactors. The "Two-Phase Bubbling Bed Model" has been modified to account for PSD effects. For the reactor of wide particle size distribution operated at high gas velocities, a single-phase axial dispersion model with closed inlet and open outlet boundary conditions appears to be suitable to predict the performance. It was also found that a high pressure drop across the gas distributor was not sufficient to maintain good performance of the distributor. The reactor efficiency in the entry region was higher for a distributor with a greater number of orifices, even though it had a lower pressure drop, than for a distributor plate with fewer larger holes. / Applied Science, Faculty of / Chemical and Biological Engineering, Department of / Graduate

An invariant formalism is developed for a two-body system in a flat spacetime interacting by the exchange of particles of zero proper mass. A solution, to second order, of the equations of motion is obtained. The principle of equivalence is applied to study the motion of a system of particles in a uniform gravitational field. The equations of motion are then generalized to a Riemannian spacetime and the acceleration of non-spinning point-particles in a gravitational field is briefly discussed. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

In gas-solid fluidized bed reactors, such as those employed for polyethylene production, the generation of electrostatic charge is almost unavoidable. Electrostatic charges are generated due to the continuous contacts between particles and particles and the reactor wall. In such processes, accumulation of electrostatic charge causes a layer of particles to adhere to the reactor wall, a problem known as “sheeting” in polyolefin industry. Sheeting results in frequent reactor shutdowns for clean-up and in turn significant economic loss. The overall focus of this research is to better understand the underlying mechanisms of charge generation in gas-solid fluidized beds to ultimately be able to find means to reduce or eliminate this problem. The specific objective of this thesis is to determine the effect of fluidizing particle size on the degree of bed electrification and reactor wall coating. The experimental program involved the fluidization of polyethylene resins received directly from commercial reactors (i.e., having a wide size distribution of 20-1500 micron), as well as mono-sized large particles (600-710 micron) and binary mixture of small particles (200-300 micron and 300-425 micron with fractions up to 20 wt%) and large particles (600-710 micron). Experiments were carried out under atmospheric conditions in 3D fluidization columns housing two Faraday Cups for electrostatic charge measurement. For all conditions, the charge, mass and size distribution of particles fouled on the reactor wall as well as the layer thickness were measured and compared. Fluidization of the resins as received resulted in a certain size of particles (400 µm and smaller) to adhere to the column wall. For binary mixtures, the particles layer formed on the reactor wall mainly consisted of the smaller particles. Although the extent of wall coating declined as the amount of the smaller particles increased, but the smaller particles had a much higher net specific charge and thus replaced the large particles within the wall coating. Such high charge of small particles accumulated on the column wall in turn prevented the wall coating growth due to repelling the oppositely charged particles to the bulk of the bed. Regardless of the charge polarity of the bulk and wall particles, the wall fouling formation mechanism was found to be similar. Between the two sizes of small particles tested, the 212-300 micron particles gained a higher net specific charge than 300-425 micron particles. Bipolar charging due to small and large particles contacts was detected within the bulk of the bed and the wall coating.

The particle-bubble interaction is found in industrial applications with the purpose of selective separation of materials especially in the mining industry. The separation is achieved with the use of bubbles that collect particles depending on their hydrophobicity. There are few experimental studies involving a single interaction between a bubble and a particle. The purpose of this work is to understand this interaction by the study of a single bubble interacting with a single particle. Experiments were conducted using ultra-pure water, glass particles and air bubbles. Single interactions of particles with bubbles were observed using two high speed cameras. The cameras were placed perpendicular to each other allowing to reconstruct the three-dimensional position of the particle, the bubble and the particle-bubble aggregate. A single size of particle was used varying the size for the bubbles. It was found that the attachment of a particle to a bubble depends on its degree of hydrophobicity and on the relative position of the particle and the bubble before they encounter.

Anammox (anaerobic ammonium oxidation) process is a one-step conversion of ammonia into nitrogen gas with nitrite as an electron acceptor. It has been developed as a sustainable technology for ammonia removal from wastewater in the last decade. For wastewater treatment, anammox biomass was widely developed as microbial aggregate where the conditions for enrichment of anammox community must be delicately controlled and growth of other bacteria especially NOB should be suppressed to enhance nitrogen removal efficiency. Little is known about the distribution of microbial aggregates in anammox process. Thus the objective of our study was to assess whether segregation of biomass occurs in granular anammox system. In this study, a laboratory-scale sequential batch reactor (SBR) was successfully operated for a period of 80 days with granular anammox biomass. Temporal and spatial distribution of microbial aggregates was studied by particle characterization system and the distribution of functional microbial communities was studied with qPCR and 16s rRNA amplicon pyrosequencing. Our study revealed the spatial and temporal distribution of biomass aggregates based on their sizes and density. Granules (>200 μm) preferentially accumulated in the bottom of the reactor while floccules (30-200 μm) were relatively rich at the top layer. The average density of aggregate was higher at the bottom than the density of those at the top layer. Degranulation caused by lack of hydrodynamic shear force in the top layer was considered responsible for this phenomenon. NOB was relatively rich in the top layer while percentage of anammox population was higher at the bottom, and anammox bacteria population gradually increased over a period of time. NOB growth was supposed to be associated with the increase of floccules based on the concurrent occurrence. Thus, segregation of biomass can be utilized to develop an effective strategy to enrich anammox and wash out NOB by shortening the settling time and withdrawing floccular biomass from the top of the reactor.

The main objective of this thesis is to study and investigate the production of massive vector bosons (W+ and W−). This a priori mentioned production is not sensitive to hot nuclear matter effects because of the weak coupling nature of these vector bosons. Thus, in heavy ion collisions they provide a good reference for the medium-induced effects on other probes. The production mechanism of these vector bosons is highly isospin dependent and thus they are affected by the initial state effects. Initial state effects include isospin, Fermi motion, EMC effect, shadowing and nuclear absorption. Hence their production in lead-lead (Pb-Pb) and proton-lead (p-Pb) collisions can be used to test some of these initial state effects. In this thesis only two of these initial state effects will be considered namely, isospin and shadowing (referring to shadowing and anti-shadowing). Eke, these vector bosons can be used to provide a non-arbitrary reference to the probes affected by the medium. Traditionally, in heavy ion collisions, hard processes are expected to scale with the number of binary collision thus a precise study of these vector bosons can be used to test the factorisation assumed in models used to determine centrality. This unique property of electroweak (W) bosons makes them essential probes to study the possible inherent bias in centrality determination. In proton-proton (pp) collisions, their production can be used to obtain information on quark parton distribution functions (PDF). The data used in the analysis was collected by A Large Ion Collider Experiment (ALICE) at the Large Hadron Collider (LHC). The ALICE detector is designed to study ultrarelativistic heavy-ion collisions, in which a hot and dense, strongly-interacting medium is created. The production of W bosons is studied in p-Pb, p-p and Pb-Pb collisions at 5.023, 8 and 5.023 TeV centre-of-mass energies, respectively. The forward muon spectrometer with the pseudorapidity acceptance −4.0 < ŋ < −2.5 is used. W bosons are studied via the inclusive single muon differential pT spectrum.

Bibliography: pages 71-72. / Perturbative quantum chromodynamics is developed in a spherical cavity using a symmetric form of the Gell-Mann and Low theorem. This formalism allows one to generate any desired term in the perturbation series, in a manner which is similar to the familiar Feynman rules in free space. All corrections to order eg² in the electromagnetic and strong coupling constants which contribute to the magnetic moment of a baryon are generated using this formalism. The O(eg²) radiative corrections to the magnetic moment of the nucleon are calculated here in an arbitrary covariant gauge. The gauge-dependent parts are found to vanish identically, and the divergences arising from the loop diagrams cancel amongst each other, making renormalization unnecessary. However, it is shown here that one can, if it is necessary, remove the divergences from the cavity diagrams by subtracting from them a singular factor which is found using dimensional regularization in the analogous free-space diagrams.

A particle accelerator simulation which straddles the gap between multi-particle and moment codes is derived. The hybrid approach represents the beam using macro-particles which contain discrete longitudinal coordinates and transverse second moments. The discretization scheme for the macro-particles is derived using variational principles, as a natural extension of well known variational approaches. This variational discretization allows for exact transverse emittance conservation. The electrostatic self-potential is discrete in the longitudinal direction and solved semi-analytically in the transverse direction using integrated Green’s functions. The algorithm is implemented and tested against both a moment and multi-particle code. / Graduate

The separation efficiency of a triboelectrostatic separation (TES) for fine coal cleaning depends profoundly on the surface charges of the particles involved. In general, the larger the difference between the charges of the particle to be separated, the higher the separation efficiency. The premise that coal and mineral matter can be triboelectrically charged differently serves as a basis for the TES process. In order to improve the separation performance, it is apparent that a highly efficient charger is needed for the TES unit, as well as the information on the triboelectrification mechanisms of the coal and mineral matter. Tribo- or contact electrification is a phenomenon in which electrical charge is usually transferred form one material to another, when two dissimilar materials are brought into rubbing or contact. In the present work, the triboelectrification mechanisms of coal, quartz, and pyrite were investigated in an in-line static mixer charger. A new in-situ charge-measuring device has been developed, in which an in-line mixer charger is located in side a Faraday cage. This makes it possible to observe the charging mechanisms of the particles when they pass through the mixer. This device was used to study the tribocharging mechanisms of coal, quartz, and pyrite as functions of the air velocity, particle feed rate, particle size, temperature, ash content, and the work functions of the materials that make up the in-line mixer. Evidence suggests that the charge transfer mechanisms of coal and mineral matter be due to electrons. A new turbocharger designed and developed in the present study has been tested and used to investigate the triboelectrification mechanisms of coal and quartz. The charge measurements were conducted using a developed on-line charge-measuring device, which is based on the principle of the Faraday cage. The tribocharging mechanisms of coal and quartz were investigated as functions of the particle feed rate, particle size, rotor-blade rotation speed, ash content, and the type of the materials used to construct the turbocharger. The information on the charging mechanisms of the coal and quartz will be useful for improving the triboelectrification process and subsequently the design of a TES unit. / Ph. D.