Carbon dioxide CO₂capture through hydrate formation is a novel technology under consideration as an efficient means of separating CO₂from flue/fuel gas mixtures for sequestration and enhanced oil recovery operations. This thesis examines post-combustion capture of CO₂from fossil-fuel power plant flue-gas streams through hydrate formation in a silica gel column. Power plant flue-gas contains essentially CO₂and nitrogen (N2) after suitable pre-treatment steps, thus a model flue-gas comprising 17% co₂and 83% N2 was used in the study. Previous studies employed a stirred-tank reactor to achieve water-gas contact for formation of hydrates; recent microscopic studies involved using water dispersed in silica gel to react with gas, showing potential for improved hydrate formation rates without the need for agitation. This study focuses on macroscopic kinetics of hydrate formation in silica gel to evaluate hydrate formation rates, CO₂separation efficiency and determining optimal silica gel properties as a basis for a CO2 capture process. Spherical silica gels with 30.0 and 100.0 nm pore sizes and 40-75 and 75-200 μm particle sizes were studied to determine pore size and particle size effects on hydrate formation. 100.0 nm pores achieved higher gas uptake and CO₂recovery over the 30.0 nm case. Improved CO₂separation was obtained when 75-200 μm particles with 100.0 nm pores were used. The two effects observed are due to improved gas diffusion occurring with larger pore and particle size, favouring increased hydrate formation. Compared to stirred-tank experiments, results in this study show a near four-fold increase in moles of gas incorporated in the hydrate per mole of water, showing that improved water-to-hydrate conversion is obtained with pore-dispersed water. At similar experimental conditions, CO₂recovery improved from 42% for stirred-tank studies to 51% for the optimum silica (100.0 nm 75-200 μm) determined in this study. Finally, effects of tetrahydrofuran (THF) - an additive that reduces operating pressure were evaluated. Experiments with 1 mol% THF, the optimum determined from previous stirred tank studies, showed improved gas consumption in silica but reduced CO₂recovery, indicating that the optimum concentration for use in silica is different from that in stirred-tank experiments. / Applied Science, Faculty of / Chemical and Biological Engineering, Department of / Graduate

Microporous metal organic frameworks (MOFs) are a novel class of materials formed through self-assembly of inorganic and organic structural building units (SBUs). They show great promise for many applications thanks to record-breaking internal surface areas, high porosity as well as a wide variety of possible chemical compositions. Molecular simulation has been instrumental in the study of MOFs to date, and this thesis work aims to validate and expand upon these efforts through two distinct computational MOF investigations. Current separation technologies used for CO2/N2 mixtures, found in the greenhouse gas-emitting flue gas generated by coal-burning power plants, could greatly benefit from the improved cost-effective separation MOF technology offers. MOFs have shown great potential for CO2 capture due to their low heat capacities and high, selective uptake of CO2. To ensure that simulation techniques effectively predict quantitative MOF gas uptakes and selectivities, it is important that the simulation parameters used, such as force fields, are adequate. We show that in all cases explored, the force field in current widespread use for N2 adsorption over-predicts uptake by at least 50% of the experimental uptake in MOFs. We propose a new N2 model, NIMF (Nitrogen in MoFs), that has been parameterized using experimental N2 uptake data in a diverse range of MOFs found in literature. The NIMF force field yields high accuracy N2 uptakes and will allow for accurate simulated uptakes and selectivities in existing and hypothetical MOF materials and will facilitate accurate identification of promising materials for CO2 capture and storage as well as air separation for oxy-fuel combustion. We also present the results of grand canonical and canonical Monte Carlo (GCMC and canonical MC), DFT and molecular dynamics (MD) simulations as well as charge density analyses, on both CO2 and N,N-dimethylformamide adsorbed in Ba2TMA(NO3) and MIL-68(In), two MOFs with non-equivalent inorganic structural building units. We demonstrate the excellent agreement found between our simulation results and the solid-state NMR (SSNMR) experiments carried out by Professor Yining Huang (Western University) on these two MOFs. Molecular simulation enables discoveries which complement SSNMR such as the number, distribution and dynamics of guest binding sites within a MOF. We show that the combination of SSNMR and molecular simulation forms a powerful analytical procedure for characterizing MOFs, and this novel set of microscopic characterization techniques allows for the optimization of new and existing MOFs.

In this thesis computational chemistry has been used to accelerate experimental discovery in the fields of ice recrystallization inhibitors for cryopreservation and ultra-microporous MOFs for carbon dioxide capture and storage. Ice recrystallization is one of the leading contributors to cell damage and death during the freezing process. This occurs when larger ice crystal grains grow at the expense of smaller ones. Naturally occurring biological antifreeze molecules have been discovered but only operate up to -4oC and actually exasperate the problem at temperatures lower than this. Recently, the group of Dr. Robert Ben have been successful in synthesizing small organic molecules which are capable of inhibiting the growth of ice crystals during the freezing process. They have built a library of diverse compounds with varying functionalities and activity. Chemical intuition has been unsuccessful in finding a discernible trend with which to predict activity. Herein we present work where we have utilized a quantitative structure activity relationship (QSAR) model to predict whether a molecule is active or inactive. This was built from a database of 124 structures and was found to have a positive find rate of 82%. Proposed molecules that had yet to be synthesized were predicted to active or inactive using our method and 9/11 structures were indeed active which is strikingly consistent to the 82% find rate. Our efforts to aid in the discovery of these novel molecules will be described here. Metal organic frameworks (MOFs) are a relatively new class of porous materials which have taken the academic community by storm. These three-dimensional crystalline materials are built from a metal node and an organic linker. Depending on the metals and organic linkers used, MOFs can possess a vast range of topologies and properties that can be exploited for specific applications. Ultra-microporous MOFs possess relatively small pores in the range of 3.5 Å to 6 Å in diameter. These MOFs have some structural advantages compared to larger pored MOFs such as molecular sieving, smaller pores which promote strong framework-gas interactions and cooperative effects between guests, and longer shelf-life due to small void volumes and rigid frameworks. Here we present newly synthesized ultra-microporous MOFs based on isonicotnic acid as the organic linker with Ni and Mg as the metal centre. Despite having such small pores, Ni-4PyC exhibits exceptionally high CO2 uptake at high pressures. Furthermore, Mg-4PyC exhibits novel pressure dependent gate-opening behaviour. Computational simulations were employed to investigate the origin of high CO2 uptake, predict high pressure (>10bar) isotherms, quantify CO2 binding site positions and energies, and study uptake-dependent linker dynamics. This work hopes to provide experimentalists with some explanation to these interesting unexplained phenomena and also predict optimal properties for new applications.

In this paper, a Kinect-based distributed and real-time motion capture system is developed. A trigonometric method is applied to calculate the relative positions of Kinect v2 sensors with a calibration wand and register the sensors’ positions automatically. By combining results from multiple sensors with a nonlinear least square method, the accuracy of motion capture is optimized. Moreover, to exclude inaccurate results from sensors, a computational geometry is applied in the occlusion approach to discover occluded joint data. The synchronization approach is based on the NTP protocol, which synchronizes the time between the clocks of a server and of clients dynamically, leading to the proposed system being real time. Experiments to validate the proposed system are conducted from the perspective of calibration, occlusion, and accuracy. More specifically, the mean absolute error of the calibration results is 0.73 cm, the proposed occlusion method is tested on upper and lower limbs, and the synchronization component guarantees the clock synchronization and real-time performance for more than 99% of the measurement process. Furthermore, to demonstrate the practical performance of our system, a comparison with previously developed motion capture systems (the linear trilateration approach [52] and the geometric trilateration approach [51]) with the benchmark Opti Track system is performed for the tracked joints of the head, shoulder, elbow, and wrist, therein showing that the accuracy of our proposed system is 38.3% and 24.1% better than the aforementioned two trilateration systems. Quantitative analysis is also conducted on our proposed system with the commercial inertial motion capture system Delsys smart sensor system by comparing the measurements of lower limbs (i.e., hips, knees, and ankles), and the standard deviation of our proposed system’s measurement results is 4.92 cm.

Laboratory measurements of primitive and differentiated meteorites have been made in order to understand the origin of isotopic anomalies. The element Zr is chosen for analysis, due to its potential for nuclear and astrophysical applications. Zirconium has five stable isotopes that are produced in different (neutron–capture) nucleosynthetic processes. By analysing the Zr isotope composition of meteorites, we are able to track the mixing of various neutron capture processes in the early Solar System. Measurements have been performed on carbonaceous, ordinary and enstatite chondrites, eucrites, the Moon and Earth. Samples are crushed, digested and passed through a two stage anion exchange separation to obtain a clean Zr fraction. All Zr measurements are made on a Nu Plasma multiple–collector inductively coupled plasma mass spectrometer (MC–ICPMS). The results indicate that the bulk of refractory Ca–Al rich inclusions of the Allende meteorite are characterised by uniform enrichments (around 2ε) of the neutron–rich isotope 96Zr, and potentially coupled with excesses reported for the neutron rich isotope 50Ti, indicating that both nuclides may have similar astrophysical origins. Analysis of bulk rock carbonaceous chondrites reveal 96Zr excesses (not exceeding 1ε) that scale with the abundance of CAIs. However, widespread 96Zr correlations are also seen, accompanied by minor depletions in 91Zr, which suggest the solar nebular had experienced thermal heating of some sort, altering the initial (possibly uniform) Zr isotope composition of the early Solar System from which planetary bodies formed.

Environmental concerns about the effect of greenhouse gases have led governments to regulate industrial CO2 emissions, including through emissions caps, trading and penalties, thus creating economic incentives to reduce CO2 emissions. This research focuses on strategies to reduce CO2 emissions from energy systems in the context of the process industries. In the process industries, energy systems consume fuel to generate steam and power for site process units. Improving energy efficiency can reduce costs of energy generation and use, as well as CO2 emissions. This research develops an integrated design and optimisation methodology for energy systems, allowing effective capture and control of carbon dioxide emissions. The first focus of this study is to develop a systematic approach to evaluate combinatorial strategies for reducing CO2 emissions, based on a techno-economic analysis. A conceptual design procedure with hierarchical decision-making is introduced to combine CO2 emissions reduction strategies, accounting for interactions between site components, including the heat exchanger network and utility system. CO2 emissions reduction options considered in development of this procedure include process integration techniques for improving the energy efficiency of the site and fuel switching. The proposed approach considers trade-offs between the economy of energy retrofit and CO2 emissions penalties. Opportunity for reducing the CO2 penalty is included in the economic evaluation of the combined emissions reduction strategies. A mathematical model for simultaneous optimization of emissions reduction strategies is developed. In addition to emissions reduction strategies, options for trading CO2 allowances are considered in the model. The proposed mathematical method applies Mixed Integer Non Linear Programming (MINLP) optimization, which employs a superstructure of the strategies for CO2 reduction. The proposed mathematical model relates the selected options to their operating and capital costs and to their associated CO2 emissions, allowing the optimizer to search for the optimal combination of emissions reduction strategies. While the reduction in CO2 emissions through process integration techniques is based on the existing configuration of a site and the associated structural limitations, integration of Carbon Capture and Storage (CCS) technologies can provide greater mitigation of CO2 emissions from a site. However, important challenges of implementing CCS in the process industries are the energetic and economic impact of the CCS plant on the integrated site. In the second part of this study, these energy-economic issues are explored. The CCS technologies addressed in this thesis include post- and pre-combustion CO2 capture techniques. Simulation of each capture technique is carried out in process simulation software to characterize the energy performance of the CO2 capture plant. Sensitivity analyses are carried out for key parameters of the CO2 capture plant. The relationship between these key parameters and the energy balance of the capture plant is represented using a simple energy performance model for the CO2 capture plant. This model allows the integration of the CO2 capture plant with the site utility system to be explored. Interactions between the utility system and CO2 capture plant are considered. The site utility system, together with the CO2 capture plant, is optimized for minimum operating cost. The proposed procedures are illustrated by application to a case study of a medium-scale oil refinery. The results illustrate that to reduce CO2 emissions, heat integration, utility system optimization and fuel switching provide more cost-effective solutions than integrating CCS technologies. The mathematical model allows more cost-effective solutions to be identified than using sequential, conceptual methods, but the value of the conceptual method for developing insights is also illustrated. The results demonstrate that, depending on the potential of the site for increasing heat recovery and the type of fuel used on site, solutions that combine energy efficiency and fuel switching can provide up to 40% reduction in site CO2 emissions. Integrating a post-combustion CO2 capture plant with the site utility system can provide up to 90 mol% pure CO2 for sequestration; however, the high capital cost of the capture plant reduces the economic performance of the integrated site. The high heat demand of post-combustion CO2 capture for solvent regeneration increases the fuel consumption of the site and its utility system, which in turn reduces the recovery of CO2. The results reveal that pre-combustion CO2 capture can provide opportunities for heat and power generation to improve the techno-economic performance of the overall integrated site.

Aplicações de captura e acesso exploram o paradigma de computação ubíqua --- que consiste em popular o ambiente com aplicações e dispositivos computacionais a fim de auxiliar transparentemente as pessoas na realização de suas atividades --- para dar apoio à captura automática de informação em experiências ``ao vivo' e à correspondente geração de documentos passíveis de armazenamento, recuperação, visualização e extensão ao longo do tempo. Devido à sua natureza distribuída, à heterogeneidade dos dispositivos computacionais envolvidos e à diversidade nas funcionalidades providas, essas aplicações são difíceis de se construir e requerem infra-estruturas e serviços de software que auxiliem o desenvolvedor nessa tarefa. Este trabalho investiga a construção e o uso de aplicações de captura e acesso por meio do desenvolvimento da xINCA, uma infra-estrutura estendida baseada em componentes de software reutilizáveis que englobam as funcionalidades recorrentes nessa classe de aplicações. A xINCA é uma extensão da infra-estrutura INCA --- uma infra-estrutura de baixo nível que provê abstrações de comunicação para aplicações de captura e acesso. Complementares, as infra-estruturas INCA e xINCA provêem um modelo simplificado para o desenvolvimento de aplicações de captura e acesso, considerando aspectos de projeto, implementação e reuso. Associada ao modelo de armazenamento do serviço StRES, a xINCA tem ainda papel na estruturação da informação capturada com o uso de XML e tecnologias correlatas. / Capture and access applications explore the ubiquitous computing paradigm --- that basically consists on populating the environment with computational devices and applications to transparently assist people on their activities --- to support the automatic capture of information on live experiences and generate corresponding documents that can be further stored, retrieved, visualized and extended. Due to their distributed nature, heterogeneity of involved devices and variety of provided functionalities, capture and access applications are hard to build and require software infrastructures and services that help the developer out on his task. This work investigates the building and use of capture and access applications through the development of xINCA, a component-based software infrastructure comprising the most common func-tio-na-li-ties present in such a class of applications. xINCA is an extension of INCA --- a low-level infrastructure that provides communication abstractions for capture and access applications. Complementary, INCA and xINCA provide a simplified model for the development of capture and access applications, concerning design, implementation and reuse aspects. Allied with the StRES storage model, xINCA also plays an important role on the structuring of captured information by using XML and corresponding technologies.

The growing importance of multimedia content generated by ordinary users demands research for models, methods, technologies and systems that support multimedia production. Despite recent results allowing the collaborative capture of video via mobile devices, there is gap in supporting the collaborative capture of multiple media. In this dissertation we propose that ubiquitous collaborative multimedia production can be carried out by users who capture and annotate multiple media using the CMoViA mobile application. CMoViA also allows export the user-generated content to the CI+WaC, which allows them to edit the user-generated content in the form of interactive and extensible multimedia documents. The proposal demanded extending recent work reported in the literature, namely the I+WaC-IE (Interactors+WaC-Interaction Events) model, the I+WaC-Editor tool and MoViA tool. Hence, CMoViA follows the proposed CI+WaC-IE model. We discuss results from a case study, carried out in the educational domain, in which students collaboratively capture a lecture. / A crescente importância de conteúdo multimídia gerado por usuários amadores exige pesquisas por modelos, métodos, tecnologias e sistemas que apoiem a produção multimídia. Apesar dos recentes resultados que permitem captura colaborativa em vídeo utilizando dispositivos móveis, existe uma lacuna no apoio à captura colaborativa de múltiplas mídias. O trabalho apresentado nesta dissertação propõe que a produção multimídia colaborativa ubíqua possa ser alcançada por usuários que realizem a captura de múltiplas mídias e de anotações utilizando o aplicativo móvel CMoViA. CMoViA também permite que o conteúdo gerado por esses usuários seja exportado para a plataforma CI+WaC, a qual permite editar e anotar documentos multimídia interativos. Essa proposta requer a extensão de trabalho recentes reportados na literatura: o modelo I+WaC-IE (Interactors+WaC-Interaction Events), a ferramenta I+WaC-Editor e a ferramenta MoViA. Assim, a aplicação CMoViA segue o modelo CI+WaC-IE proposto neste trabalho como extensão do modelo I+WaC-IE. A proposta foi avaliada por meio de estudo de caso realizado no domínio educacional, no qual estudantes capturam colaborativamente uma palestra.

abstract: Global warming resulted from greenhouse gases emission has received widespread attention. Meanwhile, it is required to explore renewable and environmentally friendly energy sources due to the severe pollution of the environment caused by fossil fuel combustion. In order to realize a substantial adsorption process to resolve the environmental issues, the development of new adsorbents with improved properties has become the most critical issue. This dissertation presents the work of four individual but related studies on systematic characterization and process simulations of novel adsorbents with superior adsorption properties. A perovskite oxide material, La0.1Sr0.9Co0.9Fe0.1O3-δ (LSCF1991), was investigated first for high-temperature air separation. The oxygen sorption/desorption behavior of LSCF1991 was studied by thermogravimetric analysis (TGA) and fixed-bed breakthrough experiments. A parametric study was performed to design and optimize the operating parameters of the high-temperature air separation process by pressure swing adsorption (PSA). The results have shown great potential for applying LSCF1991 to the high-temperature air separation due to its excellent separation performance and low energy requirement. Research on using nanostructured zeolite NaX (NZ) as adsorbents for CO2 capture was subsequently conducted. The CO2/N2 adsorption characterizations indicated that the NZ samples lead to enhanced adsorption properties compared with the commercial zeolites (MZ). From the two-bed six-step PSA simulation, NZ saved around 30% energy over MZ for CO2 capture and recovery while achieving a higher CO2 purity and productivity. A unique screening method was developed for efficient evaluation of adsorbents for PSA processes. In the case study, 47 novel adsorbents have been screened for coal bed methane (CBM) recovery. The adsorbents went through scoring-based prescreening, PSA simulation, and optimization. The process performance indicators were correlated with the adsorption selectivity and capacities, which provides new insights for predicting the PSA performance. A new medium-temperature oxygen sorbent, YBaCo4O7+δ (YBC114), was investigated as an oxygen pumping material to facilitate solar thermochemical fuel production. The oxygen uptake and release attributes of YBC114 were studied by both TGA and a small-scale evacuation test. The study proved that the particle size has a significant effect on the oxygen pumping behavior of YBC114, especially for the uptake kinetics. / Dissertation/Thesis / Doctoral Dissertation Chemical Engineering 2020

Magnetic interference in the motion capture environment is caused primarily by ferromagnetic objects and current-carrying devices disturbing the ambient, geomagnetic field. Inertial sensors gather magnetic data to determine and stabilize their global heading estimates, and such magnetic field disturbances alter heading estimates. This decreases orientation accuracy and therefore decreases motion capture accuracy. The often used Kalman Filter approach deals with magnetic interference by ignoring the magnetic data during periods interference is encountered, but this method is only effective when the disturbances are ephemeral, and cannot not retroactively repair data from disturbed time periods. The objective of this research is to develop a method of magnetic interference mitigation for environments where magnetic interference is the norm rather than the exception. To the knowledge of this author, the ability to use inertial and magnetic sensors to capture accurate, global, and drift-free orientation data in magnetically disturbed areas has yet to be developed. Furthermore there are no methods known to this author that are able to use data from undisturbed time periods to retroactively repair data from disturbed time periods. The investigation begins by exploring the use of magnetic shielding, with the reasoning that application of shielding so as to impede disturbed fields from affecting the inertial sensors would increase orientation accuracy. It was concluded that while shielding can mitigate the effect of magnetic interference, its application requires a tedious trial and error testing that was not guaranteed to improve results. Furthermore, shielding works by redirecting magnetic field lines, increasing field complexity, and thus has a high potential to exacerbate magnetic interference. Shielding was determined to be an impractical approach, and development of a magnetic inference mitigation algorithm began. The algorithm was constructed such that magnetic data would be filtered before inclusion in the orientation estimate, with the result that exposure in an undisturbed environment would improve estimation, but exposure to a disturbed environment would have no effect. The algorithm was designed for post-processing, rather than real-time use as Kalman Filters are, which enabled magnetic data gathered before and after a time point could affect estimation. The algorithm was evaluated by comparing it with the Kalman Filter approach of the company XSENS, using the gold standard of optical motion capture as the reference point. Under the tested conditions of stationary periods and smooth planar motion, the developed algorithm was resistant to magnetic interference for the duration of testing, while the Kalman Filter began to degrade after approximately 15 seconds. In a 190 second test, of which 180 were spent in a disturbed environment, the developed algorithm resulted in 0.4 degrees of absolute error, compared to the of the Kalman Filter’s 78.8 degrees. The developed algorithm shows the potential for inertial systems to be used effectively in situations of consistent magnetic interference. As the benefits of inertial motion capture make it a more attractive option than optical motion capture, immunity to magnetic interference significantly expands the usable range of motion capture environments. Such expansion would be beneficial for motion capture studies as a whole, allowing for the cheaper, more practical inertial approach to motion capture to supplant the more expensive and time consuming optimal option.