Carbon Capture and Utilisation processes: a techno-economic assessment of synthetic fuel production from CO2

Carbon Capture and Utilisation (CCU) is seen globally as one of the available technologies that can contribute to avoiding the effects of global warming while securing energy supply by utilising CO2 as a carbon source for chemical and fuel production. This thesis has measured the technical and economic performance of seven Carbon Capture and Utilisation (CCU) process designs (Base Case Models) based on best available technology. This was the first attempt to compare different routes of similar Technology Readiness Level to manufacture a liquid fuel from CO2. In addition, this thesis also examines the techno-economic feasibility of selective CO2 capture processes from biogas streams using ionic liquids as physical absorbents to assess the potential improvements that this developing technology could have on process performance. The selected Base Case Models were modelled using the process simulation software Aspen Plus to determine mass and energy balances. In addition, an economic assessment was developed using Aspen Plus Economic Analyzer (APEA) and MS Excel to determine capital, operating and production costs. The results revealed that the synthetic route based on CO2 capture and steam methane reforming was the most promising CO2-to-fuels route since it was able to achieve the highest overall plant energy efficiency (17.9%) and the lowest fuel production costs (£95.46 per GJ [LHV]); however this process cannot currently compete commercially with conventional fossil fuels. Further research in the specific areas suggested in this work is encouraged in order to bring fuel production costs down. It was also demonstrated that the evaluated ionic liquids cannot compete with MEA in terms of bio-methane production costs; however, the simulation methodology developed in this study can be used as a basis for further work in the area since it allows consideration of ionic liquids made of any combination of cation and anion as well as different gas streams

Diagnóstico de fallos y optimización de la planificación en un marco de e-mantenimiento.

324 p.El objetivo principal es demostrar el potencial de mejora que las técnicas y metodologías relacionadas con la analítica prescriptiva, pueden proporcionar en aplicaciones de mantenimiento industrial. Las tecnologías desarrolladas se pueden agrupar en tres ámbitos: - El e-mantenimiento, relacionado fundamentalmente con el desarrollo de plataformas colaborativas e inteligentes que permiten la integración de nuevos sensores, sistemas de comunicaciones, estándares y protocolos, conceptos, métodos de almacenamiento y análisis etc. que entran continuamente en nuestro abanico de posibilidades y nos ofrecen la posibilidad de seguir una tendencia de mejora en la optimización de activos y procesos, y en la interoperabilidad entre sistemas.- Las Redes Bayesianas (Bayesian Networks ¿ BNs) junto con otras metodologías de recogida de información utilizadas en ingeniería nos ofrecen la posibilidad de automatizar la tarea de diagnóstico y predicción de fallos.- La optimización de las estrategias de mantenimiento, mediante simulaciones de fallos y análisis coste-efectividad, que ayudan a la toma de decisiones a la hora de seleccionar una estrategia de mantenimiento adecuada para el activo. Además, mediante el uso de algoritmos de optimización logramos mejorar la planificación del mantenimiento, reduciendo los tiempos y costes para realizar las tareas en un parque de activos

Persistent BCG bacilli perpetuate CD4 T effector memory and optimal protection against tuberculosis

AbstractTuberculosis (TB) remains one of the most important infectious diseases of man and animals, and the only available vaccine (BCG) requires urgent replacement or improvement. To facilitate this, the protective mechanisms induced by BCG require further understanding. As a live attenuated vaccine, persistence of BCG bacilli in the host may be a crucial mechanism.We have investigated the long term persistence of BCG following vaccination and the influence on the induced immune response and protection, using an established murine model. We sought to establish whether previously identified BCG-specific CD4 TEM cells represent genuine long-lived memory cells of a relatively high frequency, or are a consequence of continual priming by chronically persistent BCG vaccine bacilli.By clearing persistent bacilli, we have compared immune responses (spleen and lung CD4: cytokine producing T effector/TEM; TCR-specific) and BCG-induced protection, in the presence and absence of these persisting vaccine bacilli. Viable BCG bacilli persisted for at least 16 months post-vaccination, associated with specific CD4 T effector/TEM and tetramer-specific responses. Clearing these bacilli abrogated all BCG-specific CD4 T cells whilst only reducing protection by 1log10.BCG may induce two additive mechanisms of immunity: (i) dependant on the presence of viable bacilli and TEM; and (ii) independent of these factors.These data have crucial implications on the rational generation of replacement TB vaccines, and the interpretation of BCG induced immunity in animal models

Scaling Factor Estimation Using Optimized Mass Change Strategy, Part 2: Experimental Results

The mass change method is used to estimate the scaling factors, the uncertainty is reduced when, for each mode, the frequency shift is maximized and the changes in the mode shapes are minimized, which in turn, depends on the mass change strategy chosen to modify the dynamic behavior of the structure. On the other hand, the aforementioned objectives are difficult to achieve for all modes simultaneously. Thus, a study of the number, magnitude and location of the masses must be performed previously to the modal tests. In this paper, the mass change method was applied to estimate the scaling factors of a steel cantilever beam. The effect of the mass change strategy was experimentally studied by performing several modal tests in which the magnitude, the location and the number of the attached masses were change

A refined quasi-static method for precise determination of piezoelectric coefficient of nanostructured standard and inclined thin films

Piezoelectric materials are key components for applications including non-destructive testing, medical imaging, energy harvesting, ultrasonic sensors, and actuators. Among different materials exhibiting piezoelectricity, crystalline thin films are proposed as alternative candidates to replace ceramics due to their high integrability in micro-/nano-scale devices and compatibility with non-conventional flexible/wearable substrates. To measure the piezoelectric response, Berlincourt (BC) quasi-static method is proposed as one of the simplest, however for thin films this method has not yet been explored in sufficient detail. This paper reports the effects of measuring BC parameters on the resulting piezoelectric coefficient (d33) of sputter deposited ZnO with the shape of standard and inclined nanostructured thin films. Results provide comprehensive, reliable and repeatable information about true piezoelectric coefficient of thin films (6.0 ± 0.1 pC N−1 for standard; 24 ± 1 pC N−1 for inclined films) by selecting optimized parameters in BC measurements, including dynamic force (0.45 Npp), static force (1 N) and frequency (110 Hz), utilizing the protocol here named Method 2 for clamping the film, and measuring after the stage of high variability has passed (t >1200 s). Additionally, this modified BC has allowed the indirect estimation of stress accumulated in the ZnO lattice during measurements, offering a reliable and repeatable method for the determination of true d33 in crystalline thin films

Gade4all: Developing Multi-platform Videogames based on Domain Specific Languages and Model Driven Engineering

The development of applications for mobile devices is a constantly growing market which and more and more enterprises support the development of applications for this kind of devices. In that sense, videogames for mobile devices have become very popular worldwide and are now part of highly profitable and competitive industry. Due to the diversity of platforms and mobile devices and the complexity of this kind of applications, the development time and the number of errors within that development process have increased. The productivity of the developers has also decreased due to the necessity of using many programming languages in the development process. One of the most popular strategies is to employ specialized people to perform the development tasks more efficiently, but this involves an increase of the costs, which makes some applications economically unviable. In this article we present the Gade4all Project, consisting in a new platform that aims to facilitate the development of videogames and entertainment software through the use of Domain Specific Languages and Model Driven Engineering. This tool makes possible for users without previous knowledge in the field of software development to create 2D videogames for multiplatform mobile devices in a simple and innovative way

Critical and Near-Critical Branching Processes

Scale-free dynamics in physical and biological systems can arise from a variety of causes. Here, we explore a branching process which leads to such dynamics. We find conditions for the appearance of power laws and study quantitatively what happens to these power laws when such conditions are violated. From a branching process model, we predict the behavior of two systems which seem to exhibit near scale-free behavior--rank-frequency distributions of number of subtaxa in biology, and abundance distributions of genotypes in an artificial life system. In the light of these, we discuss distributions of avalanche sizes in the Bak-Tang-Wiesenfeld sandpile model.Comment: 9 pages LaTex with 10 PS figures. v.1 of this paper contains results from non-critical sandpile simulations that were excised from the published versio

On random flights with non-uniformly distributed directions

This paper deals with a new class of random flights $\underline{\bf X}_d(t),t>0,$ defined in the real space $\mathbb{R}^d, d\geq 2,$ characterized by non-uniform probability distributions on the multidimensional sphere. These random motions differ from similar models appeared in literature which take directions according to the uniform law. The family of angular probability distributions introduced in this paper depends on a parameter $\nu\geq 0$ which gives the level of drift of the motion. Furthermore, we assume that the number of changes of direction performed by the random flight is fixed. The time lengths between two consecutive changes of orientation have joint probability distribution given by a Dirichlet density function. The analysis of $\underline{\bf X}_d(t),t>0,$ is not an easy task, because it involves the calculation of integrals which are not always solvable. Therefore, we analyze the random flight $\underline{\bf X}_m^d(t),t>0,$ obtained as projection onto the lower spaces $\mathbb{R}^m,m<d,$ of the original random motion in $\mathbb{R}^d$. Then we get the probability distribution of $\underline{\bf X}_m^d(t),t>0.$ Although, in its general framework, the analysis of $\underline{\bf X}_d(t),t>0,$ is very complicated, for some values of $\nu$, we can provide some results on the process. Indeed, for $\nu=1$, we obtain the characteristic function of the random flight moving in $\mathbb{R}^d$. Furthermore, by inverting the characteristic function, we are able to give the analytic form (up to some constants) of the probability distribution of $\underline{\bf X}_d(t),t>0.$Comment: 28 pages, 3 figure