As the world pushes for ‘greener’ technologies and carbon neutrality, efforts have focused on creating novel ways to mitigate humankind’s carbon footprint. Carbon capture and storage (CCS) has become a prevalent technique that has proven to be an effective long-term method to safely relocate excess carbon dioxide (CO2) into subsurface formations. However, CCS is a newer technique which requires constant monitoring due to potential leakage pathways present in CO2 storage sites; therefore, a preventive approach to seal leakage pathways is recommended. This dissertation explores the potential of CO2-sensitive polyacrylamide (CO2-SPAM) as a novel sealing agent for enhanced oil recovery (EOR) and CCS applications. This manuscript explores the strength and weaknesses of various CO2-triggered chemicals and selects the appropriate fit for subsurface in-situ sealing. Relevant literature shows that CO2-SPAM can significantly reduce permeability in porous media. Additionally, organically cross-linked polyacrylamide-based gels, of which CO2-SPAM is one, are thermally stable, resistant to low pH levels, highly injectable, and widely used in various industrial processes. These characteristics make CO2-SPAM a suitable candidate for in-situ sealing. Further studies were performed to comprehend the chemical mechanism, rheological behavior, and injection effects of CO2-SPAM into subsurface formations. Firstly, past literature knowledge and organic chemistry principals were used to develop the complete chemical breakdown of CO2-SPAM gel’s synthesis. Secondly, the effect of salt and polyacrylamide (PAM) concentrations on gelation time, gel strength and viscosity were tested through qualitative (Sydansk gel strength coding system) and quantitative methods (rheometer measurement). The results showed that high salinities increase gelation time and decrease gel strength and viscosity, while high PAM concentrations do the opposite. Lastly, the effects on geomechanical stresses caused by CO2-SPAM injection into the subsurface are also addressed by using the image well method for pore pressure estimation, and frictional faulting theory. The final results determined that the injection of aqueous CO2-SPAM would induce seismicity in normal faulting zones dipping at a large array of angles in the plane of failure. These findings are significant as they determine the potential of induced seismicity in the area of CCS, which in this case was the Raton basin.

[pt] O ensino de computação gráfica aplicada é de muita importância no processo de simulação computacional de problemas de engenharia. Atualmente, muitos programas de computador, de fácil utilização, têm melhorado este trabalho, como é o caso do MATLAB. A geração e manipulação de um modelo geométrico, que é a forma mais realista e apropriada de representar o problema a ser estudado, são etapas muito importantes na simulação computacional. O uso do mouse permite que estas etapas se tornem mais interativas e de fácil compreensão. Por este motivo, neste trabalho desenvolve-se uma classe genérica no contexto da programação orientada a objetos, no ambiente MATLAB, que permite gerenciar eventos de mouse em um canvas. O objetivo desta classe é ser utilizada no desenvolvimento de programas gráficos e interativos em MATLAB, principalmente para fins educacionais. Visando atender a essas expectativas, adotou-se a Orientação a Objetos, que possibilita a criação de códigos reutilizáveis. Aliada a essa técnica, utiliza-se a Unified Modeling Language, uma linguagem gráfica que permite a visualização, construção e documentação do desenvolvimento de um sistema computacional orientado a objetos. Para determinar o correto funcionamento e praticidade da classe desenvolvida, são implementadas duas aplicações interativas no software MATLAB; a primeira para desenhar pórticos planos em 2D e a segunda para demostrar o funcionamento do círculo de Mohr para estado plano de tensões. / [en] Teaching of applied computer graphics is of great importance in computational simulation of engineering problems. Currently, many user- friendly computer programs have improved this work, as is the case with MATLAB. The generation and manipulation of a geometric model, which is a more realistic and appropriate way to represent the problem to be studied, are very important steps in the computational simulation. The use of the mouse allows these steps to become more interactive and easy to understand. For this reason, in this work a generic class is developed in the context of object-oriented programming (OOP) in the MATLAB environment, which allows managing mouse events in a canvas. The goal of this OOP class is to be used as a base class in the development of graphics and interactive programs in MATLAB, mainly for educational purposes. In order to meet these expectations, an OOP paradigm was adopted, which enables the creation of reusable codes. Together to this technique, the Unified Modeling Language (UML) is used, a graphic language that allows the visualization, construction and documentation of the development of an object oriented computational system. To determine the correct functioning and practicality of the developed class, two interactive applications are implemented in MATLAB; the first to draw frame structures in 2D and the second to demonstrate the Mohr circle for stress state.

This dissertation is concerned with the foundations in volume unstable soils and objects disorders which are related to this. The thesis was focused on the study of clay and loess soils which are abundant in the geological profile of the Czech Republic. First, the formation of the two groups of soils is introduced, then their properties are examined and finally the influence of vegetation on the former type and the influence of collapsibility in the latter type are investigated. The conclusion is, in fact, a recommendation on the design of structures so that the system of clay / structure is not damaged and that structures are not subject to renovations. Several instance of problems with structures are discussed which were subject to structural repairs employing both a civil and geotechnical engineers.