Dissertations / Theses on the topic 'CCUs'

The purpose of this research was to describe the relationships among patient characteristics, care processes, and care outcomes for patients in a coronary care unit (CCU). The sample consisted of 179 CCU patients. Data collectors reviewed charts and retrieved the chart information needed to measure the operational variables of APACHE II score (Acute Physiology and Chronic Health Evaluation II), years of age, CCU length of stay, nurse to patient ratio, and mortality. Descriptive statistics were used to analyze the demographic data of the patient characteristics. Correlational statistics were used to analyze the five operational variables in the "CCU Patient Outcomes Model." Pearson correlations revealed significant positive relationships between APACHE II score and age and nurse to patient ratio. Point Biserial correlations revealed significant positive relationships between mortality and APACHE II score and nurse to patient ratio. Patient characteristics were related to care processes. Patient characteristics and care processes were related to patient outcomes.

Carbon capture, utilization and storage (CCUS) in confined saline aquifers in sedimentary formations has the potential to reduce the impact of fossil fuel combustion on climate change by storing CO2 in geologic formations in perpetuity. At PT conditions relevant to CCUS, CO2 is less dense than the pre-existing brine in the formation, and the more buoyant CO2 will migrate to the top of the formation where it will be in contact with cap rock. A typical cap rock is clay-rich shale, and interactions between shales and CO2 are poorly understood at PT conditions appropriate for CCUS in saline formations. In this study, the interaction of CO2 with clay minerals in the cap rock overlying a saline formation has been examined, using Na-rich montmorillonite as an analog for clay-rich shale. Attenuated Total Reflectance -- Fourier Transform Infrared Spectroscopy (ATR -FTIR) was used to identify potential crystallographic sites (AlAlOH, AlMgOH and interlayer space) where CO2 could interact with montmorillonite at 35"C and 50"C and from 0-1200 psi.  Analysis of the data indicates that CO2 that is preferentially incorporated into the interlayer space, with dehydrated montmorillonite capable of incorporating more CO2 than hydrated montmorillonite. No evidence of chemical interactions between CO2 and montmorillonite were identified, and no spectroscopic evidence for carbonate mineral formation was observed.  Further work is needed to determine if reservoir seal quality is more likely to be degraded or enhanced by CO2 - montmorillonite interactions.
Master of Science

The thesis focuses on CCS and CCU technologies, which could find application in industry and other sectors in the future. These technologies are used to reduce CO2 emissions, mainly from point sources. This thesis provides a comprehensive overview and division of CCS and CCU technologies and points out negative effects of its installation. Part of the work is also a comparison of individual steps of technology, both from an energetic and financial point of view. The aim is to show a wide range of influences on the final price and a significant discrepancy in the results of some scientific works. At the same time, in some parts, you can find a detailed description of individual parts of the technology.

This research study explored the meanings former patients attributed to being on long-term mechanical ventilation in a critical care unit (CCU). An interpretive phenomenological-ontological perspective informed by the philosophical tenets of Heidegger (1927/1962) was used to examine the lived experience of a group of people who had previously been hospitalised in one of three critical care units in southeast Queensland, Australia, during which time they were on a mechanical ventilator for a period of seven days or more. Data were collected using 14 unstructured audio-taped interviews from participants, who had indicated that they were willing and able to recall aspects of their critical care experience. The data were analysed using the method developed by van Manen (1990). A total of nine people participated in the study, of which six were male and three female. Their ages ranged from 21 to 69 years. Thematic analysis of the data revealed four themes: Being thrown into an uneveryday world; Existing in an uneveryday world; Reclaiming the everyday world; and Reframing the experience. Throughout the description of these themes, excerpts from the interviews with the participants are provided to demonstrate, and bring to light the meaning and interpretations constructed. From this thematic analysis, a phenomenological description drawing on Heidegger's tenets of Being was constructed. Titled Being at its most elusive, this description showed that participants experienced momentary lapses of: situation, engagement, concern and care, temporality, and the ability to self-interpret. These findings highlight and affirm the relevance of Heidegger's ontological tenets to reveal Being. The findings of this study served as a basis for a number of recommendations relating to nursing practice, education and research. Recommendations relating to practice include: constructing a more patient-friendly critical care environment, increased involvement of patients and their families in decision making and patient care activities; ensuring adequate critical care nursing staff levels; ensuring and maintaining appropriate skill level of critical care nurses; enhancing methods of communication with patients; planning for effective patient discharge and adoption of a designated nurse position for discharge planning; providing opportunities for follow up contact of patients once they are discharged from CCU; and promoting the establishment of follow up services for former CCU patients, and their families. Recommendations relating to critical care education include: incorporating more in-depth information of the psychological and social aspects of patient and family care into care planning; incorporating communication and counselling education and training to assist nurses caring for mechanically ventilated patients, and their families; further education regarding the role and responsibilities of patient discharge planning from CCU; incorporating more advanced research skills training and utilisation of research findings into practice; and the provision of appropriate and ongoing training and education in areas such as manual handling and communication skills for all health care staff involved in the direct care of CCU patients. This study also recommended that further research be undertaken to: examine and compare different sedative and analgesic protocols and their effects on the incidence of nightmares and hallucinations reported by CCU patients; replicate this study in a group of patients from different cultural or ethnic backgrounds; evaluate the efficacy of current methods for communicating with intubated and mechanically ventilated patients in the CCU; develop, test and evaluate the efficacy of new methods for communicating with intubated and mechanically ventilated patients in the CCU; examine CCU patients' perceived level of control and power; explore the extent and type of involvement patients would like to have in their care whilst in the CCU; investigate the extent and type of problems experienced by CCU patients after discharge; explore the usefulness and appropriateness of personal diaries for individual patients as an aid to assist in understanding and resolving their CCU experience; and examine the value of follow up contacts by CCU staff to former patients and their families. In summary, the findings from this study add substantial knowledge to critical care nurses' understanding and knowledge about what it means to be on long-term mechanical ventilation in a critical care unit. Findings will help inform future critical care nursing practice and education, and the provision of holistic and evidenced-based care.

This research study explored the meanings former patients attributed to being on long-term mechanical ventilation in a critical care unit (CCU). An interpretive phenomenological-ontological perspective informed by the philosophical tenets of Heidegger (1927/1962) was used to examine the lived experience of a group of people who had previously been hospitalised in one of three critical care units in southeast Queensland, Australia, during which time they were on a mechanical ventilator for a period of seven days or more. Data were collected using 14 unstructured audio-taped interviews from participants, who had indicated that they were willing and able to recall aspects of their critical care experience. The data were analysed using the method developed by van Manen (1990). A total of nine people participated in the study, of which six were male and three female. Their ages ranged from 21 to 69 years. Thematic analysis of the data revealed four themes: Being thrown into an uneveryday world; Existing in an uneveryday world; Reclaiming the everyday world; and Reframing the experience. Throughout the description of these themes, excerpts from the interviews with the participants are provided to demonstrate, and bring to light the meaning and interpretations constructed. From this thematic analysis, a phenomenological description drawing on Heidegger's tenets of Being was constructed. Titled Being at its most elusive, this description showed that participants experienced momentary lapses of: situation, engagement, concern and care, temporality, and the ability to self-interpret. These findings highlight and affirm the relevance of Heidegger's ontological tenets to reveal Being. The findings of this study served as a basis for a number of recommendations relating to nursing practice, education and research. Recommendations relating to practice include: constructing a more patient-friendly critical care environment, increased involvement of patients and their families in decision making and patient care activities; ensuring adequate critical care nursing staff levels; ensuring and maintaining appropriate skill level of critical care nurses; enhancing methods of communication with patients; planning for effective patient discharge and adoption of a designated nurse position for discharge planning; providing opportunities for follow up contact of patients once they are discharged from CCU; and promoting the establishment of follow up services for former CCU patients, and their families. Recommendations relating to critical care education include: incorporating more in-depth information of the psychological and social aspects of patient and family care into care planning; incorporating communication and counselling education and training to assist nurses caring for mechanically ventilated patients, and their families; further education regarding the role and responsibilities of patient discharge planning from CCU; incorporating more advanced research skills training and utilisation of research findings into practice; and the provision of appropriate and ongoing training and education in areas such as manual handling and communication skills for all health care staff involved in the direct care of CCU patients. This study also recommended that further research be undertaken to: examine and compare different sedative and analgesic protocols and their effects on the incidence of nightmares and hallucinations reported by CCU patients; replicate this study in a group of patients from different cultural or ethnic backgrounds; evaluate the efficacy of current methods for communicating with intubated and mechanically ventilated patients in the CCU; develop, test and evaluate the efficacy of new methods for communicating with intubated and mechanically ventilated patients in the CCU; examine CCU patients' perceived level of control and power; explore the extent and type of involvement patients would like to have in their care whilst in the CCU; investigate the extent and type of problems experienced by CCU patients after discharge; explore the usefulness and appropriateness of personal diaries for individual patients as an aid to assist in understanding and resolving their CCU experience; and examine the value of follow up contacts by CCU staff to former patients and their families. In summary, the findings from this study add substantial knowledge to critical care nurses' understanding and knowledge about what it means to be on long-term mechanical ventilation in a critical care unit. Findings will help inform future critical care nursing practice and education, and the provision of holistic and evidenced-based care.
Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Nursing
Full Text

The main theme of this work revolves around the CO2 molecule, a stable waste gas of low value, low energy and often available in large quantities in different places. This work examines some viable avenues for capturing, using, and storing CO2 (CCUS), with the ultimate goal of reducing GHG emissions and global warming. In addition, the study also examines several ways to accelerate the commercialization of carbon-based products and their technologies. Various technologies that show promising features of commercial scalability and advanced mobility. In addition, the rapid decline in the costs of many renewable sources (mainly solar and wind) has made low-cost, almost zero-carbon electricity abundant in terms of capacity and location. Consequently, this has driven some markets to offer electricity at an affordable cost and in some cases even at negative prices. As renewable electricity gradually decreases in price, there has been a greater knowledge of possible new applications (e.g. CCU and CCUS) considering turning this trend into a profitable business. This work focuses on six main aspects related to emerging CCUS processes and technologies based on renewable energies: 1. A comprehensive investigation of three emerging renewable energy technologies and processes (RETPs) (i.e., biogas and fuel cells, synthetic fuels, mineral carbonation of fly ash) that fall into the CCUS paradigm and are special forms , relatively new or advanced from major energy sources. All explanations of RETP CCUS are followed by its market share, challenges, implications for further adoption, prospects and drawbacks. 2. Analysis of experimental work related to the direct use of fuel containing CO2 of biological origin to supply an electrochemical process dedicated to the production of energy at high efficiency. In addition, the work analyzes a case study called DEMOSOFC located at a wastewater treatment plant (WWTP) in Turin, Italy. It analyzes energy production through the use of biogas produced in WWTPs and reports the results of the use of carbon (CO2 content), as it produces energy and heat (in CHP configuration) using fuel cells; specifically, solid oxide fuel cells. 3. Analysis of the experimental and modeling work carried out at the Turin Polytechnic, related to the use of the carbon molecule to produce synthetic fuels (e-methane (CH4) and e-methanol (CH3OH)) through two processes: electrolysis of the steam + methanation, and steam electrolysis + methanol production. 4. Analysis of the chemical process called mineral carbonation (MC), a carbon capture and storage (CCUS) technology that can capture large amounts of CO2 and turn it into stable carbonate products that can be easily used in the carbon market. cement and concrete. 5. Examining the potential commercialization of CCUS technologies by identifying four main markets and eight key product categories to drive new investment and innovation at an accelerated pace. The main markets and products discussed in this chapter are: (1) Markets: building materials, chemical intermediates, fuels, polymers (2) Products: carbonate aggregates, methanol, formic acid, syngas, liquid fuels, methane, polyols and polycarbonates. 6. Assess the continued increase in RETP CCUS despite the Covid-19 pandemic resulting from a mix of policies, regulations, incentives and past innovations embedded in the electricity sectors of many advanced countries.
El tema principal d'aquest treball gira al voltant de la molècula de CO2, un gas residual estable de baix valor, poca energia i sovint disponible en gran quantitat en llocs diferents. Aquest treball examina algunes vies viables per capturar, utilitzar i emmagatzemar CO2 (CCUS), amb l'objectiu final de reduir les emissions de GEH i l'escalfament global. A més, l'estudi també examina diversos camins per accelerar la comercialització dels productes a base de carboni i les seves tecnologies. Diverses tecnologies que mostren funcions prometibles d'escalabilitat comercial i mobilitat avançada. A més, la ràpida disminució dels costos de moltes fonts renovables (principalment la solar i l'eòlica) ha fet que l'electricitat de baix cost i gairebé nul·la de carboni sigui abundant en termes de capacitat i localitat. En conseqüència, això ha impulsat alguns mercats a oferir electricitat a un cost assequible i, en alguns casos, fins i tot a preus negatius. Com que l'electricitat renovable disminueix gradualment en el preu, hi ha hagut un major coneixement de les possibles noves aplicacions (per exemple, CCU i CCUS) considerant convertir aquesta tendència en una empresa rendible. Aquest treball se centra en sis aspectes principals relacionats amb processos i tecnologies CCUS emergents basades en energies renovables: 1. Una investigació exhaustiva de tres tecnologies i processos emergents d'energies renovables (RETP) (és a dir, biogàs i cèl·lules de combustible, combustibles sintètics, carbonatació mineral de cendres voladores) que entren en el paradigma CCUS i són formes especials, relativament noves o avançades de les principals fonts d'energia. Totes les explicacions de RETP CCUS van seguides de la seva quota de mercat, els reptes, les implicacions per a una major adopció, les perspectives i els inconvenients. 2. Anàlisi de treballs experimentals relacionats amb l'ús directe de combustible que conté CO2 d'origen biològic per subministrar un procés electroquímic dedicat a la producció d'energia a alta eficiència. A més, el treball analitza un estudi de cas anomenat DEMOSOFC situat en una planta de tractament d¿aigües residuals (EDAR) a Torí, Itàlia. Analitza la producció d'energia mitjançant l'ús de biogàs produït a les EDAR i informa dels resultats de l'ús de carboni (contingut en CO2), ja que produeix energia i calor (en configuració CHP) mitjançant piles de combustible; concretament, les piles de combustible d'òxid sòlid. 3. Anàlisi del treball experimental i de modelització realitzat al Politècnic de Torí, relacionat amb l'ús de la molècula de carboni per produir combustibles sintètics (e-metà (CH4) i e-metanol (CH3OH)) mitjançant dos processos: electròlisi del vapor + metanació , i l'electròlisi del vapor + producció de metanol. 4. Anàlisi del procés químic anomenat carbonatació mineral (MC), una tecnologia d'utilització i emmagatzematge de captures de carboni (CCUS) que pot capturar grans quantitats de CO2 i convertir-lo en productes carbonats estables que es poden utilitzar fàcilment al mercat del ciment i el formigó. 5. L'examen de la comercialització potencial de les tecnologies CCUS mitjançant la identificació de quatre mercats principals i vuit categories de productes fonamentals per impulsar noves inversions i innovació a un ritme accelerat. Els principals mercats i productes discutits en aquest capítol són: (1) Mercats: materials de construcció, productes intermedis químics, combustibles, polímers (2) Productes: agregats de carbonat, metanol, àcid fòrmic, syngas, combustibles líquids, metà, poliols i policarbonats. 6. Avalua l'increment continuat de RETP CCUS malgrat la pandèmia Covid-19 resultant d'una barreja de polítiques, regulacions, incentius i innovacions passades incrustades en els sectors elèctrics de molts països avançats.
Le preoccupazioni per il riscaldamento globale e il cambiamento climatico hanno innescato gli sforzi internazionali per ridurre la quantità e la concentrazione delle emissioni di CO2 per scongiurare enormi danni economici e ambientali. Negli ultimi anni, lo sviluppo di tecnologie efficienti e convenienti per ridurre le emissioni di CO2 antropogeniche ha preso piede in tutto il mondo. L'argomento principale di questo lavoro ruota intorno alla molecola di CO2, un gas di scarto a basso valore, a bassa energia e stabile, spesso disponibile in grandi quantità in singole località. Questo lavoro esamina alcune strade percorribili per catturare, utilizzare e immagazzinare la CO2 (CCUS), con l'obiettivo finale di ridurre le emissioni di gas serra e il riscaldamento globale. Inoltre, lo studio esamina anche vari percorsi per accelerare la commercializzazione dei prodotti a base di carbonio e delle loro tecnologie. Attualmente le tecnologie CCU stanno vivendo vari stadi di performance e maturità; tuttavia, ci sono progressi significativi nelle tecnologie CCU che hanno progredito negli ultimi dieci anni; varie tecnologie che mostrano una promettente scalabilità commerciale e caratteristiche di mobilità avanzate. Inoltre, il rapido declino dei costi di molte fonti rinnovabili (principalmente solare ed eolico) ha reso l'elettricità a basso costo e quasi a zero emissioni di carbonio abbondante in termini di capacità e località. Di conseguenza, questo ha spinto alcuni mercati a offrire elettricità a costi accessibili e, in alcuni casi, anche a prezzi negativi. Poiché l'elettricità rinnovabile sta gradualmente diminuendo di prezzo, c'è stato un aumento della conoscenza delle nuove applicazioni potenziali, (per esempio, CCU e CCUS) considerando di trasformare questa tendenza in un'impresa redditizia. Questo lavoro si concentra su sei aspetti principali relativi ai processi e alle tecnologie emergenti di CCUS basati sull'energia rinnovabile: 1. Un'indagine approfondita di tre tecnologie e processi emergenti di energia rinnovabile (RETP) (cioè, biogas e celle a combustibile, combustibili sintetici, carbonatazione minerale di ceneri volanti) che rientrano nel paradigma CCUS e sono speciali, relativamente nuovi, o forme avanzate delle fonti di energia tradizionali. La spiegazione di ogni RETP CCUS è seguita dalla sua quota di mercato, dalle sfide, dalle implicazioni per una maggiore adozione, dalle prospettive e dagli svantaggi. 2. Analisi del lavoro sperimentale relativo all'uso diretto del combustibile contenente CO2 di origine biologica per alimentare un processo elettrochimico dedicato alla produzione di energia ad alta efficienza. Inoltre, il lavoro analizza un caso di studio chiamato DEMOSOFC situato in un impianto di trattamento delle acque reflue (WWTP) a Torino, Italia. Esso esamina la produzione di energia utilizzando il biogas prodotto presso il WWTP e riporta i risultati dell'uso del carbonio (contenuto nella CO2) per produrre energia e calore (in configurazione CHP) utilizzando celle a combustibile; in particolare, celle a combustibile a ossido solido. 6 3. Analisi del lavoro sperimentale e modellistico svolto presso il Politecnico di Torino legato all'utilizzo della molecola del Carbonio per produrre combustibili sintetici (e-metano (CH4) ed e-metanolo (CH3OH)) attraverso due processi: elettrolisi a vapore + metanazione, ed elettrolisi a vapore + produzione di metanolo. 4. Analisi del processo chimico chiamato carbonatazione minerale (MC), una tecnologia di cattura, utilizzo e stoccaggio del carbonio (CCUS) che può catturare grandi quantità di CO2 e convertirla in prodotti carbonati stabili che possono essere facilmente utilizzati nel mercato del cemento e del calcestruzzo. Il lavoro porta avanti la prova pragmatica che la produzione MC ha il potenziale per fornire un reddito netto positivo e la sua fattibilità commerciale è un'impresa realistica. Tuttavia, la prospettiva di una nuova direzione di cementazione tramite la carbonatazione di FA è ancora in fase di maturazione ma con un grande potenziale di commercializzazione accelerata. L'intensificazione dei benefici ambientali ed economici generati da questo nuovo percorso per la cementazione sono sostanziali se paragonati agli attuali metodi di utilizzo dell'AF nell'industria delle costruzioni. Tuttavia, le politiche e i regolamenti esistenti sul carbonio, che limitano l'uso delle ceneri volanti (principalmente quelle ceneri che contengono maggiori quantità di calcio-HCFA) possono avere un impatto sul progresso delle tecnologie di cattura del carbonio e sulla commercializzazione dei prodotti a base di carbonio. 5. L'esame della potenziale commercializzazione delle tecnologie CCUS identificando quattro mercati principali e otto categorie di prodotti critici per guidare ulteriori investimenti e innovazione ad un ritmo accelerato. I finanziamenti e gli incentivi sono necessari per la maggior parte di questi prodotti per accelerare lo sviluppo e raggiungere una capacità di lancio commerciale su larga scala. I principali mercati e prodotti discussi in questo capitolo sono: (1) Mercati - materiali da costruzione, intermedi chimici, combustibili, polimeri (2) Prodotti - aggregati carbonati, metanolo, acido formico, syngas, combustibili liquidi, metano, polioli e policarbonati. 6. Valuta il continuo aumento di RETP CCUS nonostante la pandemia di Covid-19 derivante da una miscela di politiche passate, regolamenti, incentivi e innovazioni incorporati nei settori energetici di molti paesi lungimiranti. Inoltre, guarda al futuro di RETP CCUS dopo la pandemia.
Erasmus Mundus en serveis energètics sostenibles

The Earth gets warmer primarily as a result of human activity, which results in the release of greenhouse gases into the atmosphere, most notably carbon dioxide, CO2. Increasing carbon dioxide concentration brings many problems with itself such as climate change, global warming, freshwater issues, reduced soil productivity, increasing acid rains, human health issues, extinction of species and more. And developing countries have a huge share in this increase in carbon dioxide emissions. To tackle with undesirable change, new missions and technologies are needed. In the coming decades, a carbon capture, utilisation, and storage appears to be a viable problem-solving technology. Developed countries started to use these technologies, demonstrating that although zero-emission is currently unlikely, reducing pollution is entirely feasible. This paper mainly focus on this relationship and provide information for developing countries to shift from linear economy to circular economy. The idea of a "circular economy" (CE) is quickly gaining traction as a new model for sustainable development. A circular economy is one in which goods, gases and materials are removed, recycled, repaired, and reused rather than discarded, and waste from one manufacturing process is turned into a valuable input. The research development scenario aims to increase the number of CCUS plants which result with decreasing of carbon dioxide emissions. The scenario says that, four factories should come together and construct one carbon capture, utilisation and storage plant. One of the main part of this idea is capturing process begins where the greenhouse gas emit to the atmosphere. Those gases absorbed by special adsorbers and transported to main pipeline by polyethylene pipelines. The main pipeline takes all the absorbed gases to the CCUS plants. By using this system, emitted carbon dioxide will be captured before mixing to air or atmosphere.

Backside illuminated thinned CCDs have the highest response in the UV and blue spectral region. Their use in detectors is limited due to the instability of the CCD. A low temperature oxide nearly 30 Å thick is grown on the acid thinned backside to tie up dangling bonds. The oxide carries fixed positive charges that attract and trap photogenerated electrons. A permanent and stable backside charging procedure is necessary to create a negative bias that will drive electrons to the frontside collection wells. We have shown chemisorption charging to be a novel method to permanently charge CCDs. The catalytic nature of certain metals are exploited to chemisorb oxygen as negative atomic species at the metal/oxide interface. Charging is shown to occur by depositing a thin film 10 Å of platinum on the backside. No tunneling occurs because of the thick oxide. The Passivated Platinum Film (PPtF) which utilizes a hafnium oxide antireflection coating to passivate the platinum is an effective process, but it is sensitive to the environment and discharges quickly upon hydrogen exposure. A silver catalytic coating is shown to be far superior to other charging techniques. Silver irreversibly chemisorbs oxygen and hydrogen is not dissociatively adsorbed except at temperatures < 100°K. High quantum efficiencies have been recorded for the UV-blue ranges. A slight drop is seen at cold temperatures due to interaction of water with oxygen to form hydroxyl ions. No change in QE is seen upon exposure to hydrogen or during outgassing. Silver is also one of the most transparent metals and easily deposited by evaporation. We therefore have developed a charging process which is nearly ideal for CCD imaging.

Carbon dioxide from biogas production is currently considered to be without value and isbecause of this released into the atmosphere in the biogas upgrading process. The residualgas is a potential carbon source and can create value in the biogas manufacturing process.By finding a suitable value-creating process that utilizes carbon dioxide, it can be possibleto provide both economic and environmental incentives for companies to develop theiroperations. This project explored the possibility to create value from this CO2. Through anevaluation of the technical maturity of CCU technologies, a recommendation could be givenat the end of the project. An analysis of technical barriers, such as pollutants in the gas, aswell as barriers in the form of competence and corporate culture were examined in orderto provide a reasoned recommendation. The project mapped which value-creating systemswould be suitable for biogas producers in a Swedish context. This included established methaneand carbon dioxide upgrading techniques currently in use and suitable CCU techniquesthat can interact with the selected upgrading processes and serve as value creators. Based onthis survey, it was then possible to identify common, critical variables for these systems. Thereafter,a recommendation of an appropriate CCU technology could be given depending onthe CO2 composition produced. One conclusion from the study was that carbon dioxide concentrationsfrom the residual gas was often high (approx. 97-98 %) and did not contain anycorrosive or toxic components, and that this largely depends on how the digestion reactor ishandled in the production process. Thus, questions were raised about what the actual limitationsof the CCU are, as they did not seem to be technical. CCU techniques that proved to beof particular interest were pH regulation of sewage plants, CO2 as a nutrient substrate for thecultivation of microalgae, and manufacturing of dry-ice for refrigerated transports. All of thesetechnologies currently have a sufficiently high degree of technical maturity to be installedalready today. Other CCU techniques, such as "’Power to gas”, require a high CO2 concentrationand were discarded as the literature review did not suggest the economic potential forthem as they require additional CO2 upgrading steps. Instead, CCU techniques were chosenthat could be implemented directly with the existing CO2 quality. Furthermore, it was concludedthat one reason why CCU technologies have not been widely implemented is internalbarriers between distributors and manufacturers (or users) of CCU technologies. Thus, theuse of carbon dioxide from biogas production and implementation of CCU technologies canbe promoted by eliminating barriers in companies, such as a lack of both knowledge andfinancial incentives.
Koldioxid från biogasproduktion betraktas i dagsläget som utan värde och släpps ut i atmosfärenvid uppgradering av biogas. Restgasen är en potentiell kolkälla och kan vara värdeskapandeför biogasprocessen. Genom att finna en lämplig värdeskapande process som utnyttjarkoldioxid går det att ge både ekonomiska och miljömässiga incitament till företag att utvecklasin verksamhet. I detta projekt undersöktes möjligheten att skapa värde av denna CO2.Genom en utvärdering av den tekniska mognadsgraden hos CCU-tekniker kunde en rekommendationges vid projektets slut. En analys av tekniska hinder, såsom föroreningar i gassammansättningen,såväl som hinder i form av kompetens och företagskultur undersöktes för attkunna ge en motiverad rekommendation. I projektet kartlades vilka värdeskapande systemsom skulle passa för biogasproducenter i en svensk kontext. Detta inkluderade etableradeuppgraderingstekniker för metan- och koldioxid som används i dagsläget. I projektet undersöktesäven lämpliga CCU-tekniker som kan samverka med de valda uppgraderingsprocessernaoch och agera värdeskapande. Utifrån denna kartläggning kunde det sedan anges vilkagemensamma, kritiska variabler som finns för dessa system. Därefter kunde en rekommendationav lämplig CCU-teknik ges beroende på den producerade CO2 sammansättningen. Enslutsats i projektet var att koldioxid från restgasen ofta var av hög koncentration (ca. 97-98 %)och ej innehöll några korrosiva eller toxiska komponenter, och att detta till stor del beror påhur rötkammaren är hanterad i produktionsprocessen. Således väcktes frågor kring vilka defaktiska begränsningarna för CCU är, då de inte torde vara tekniska. CCU-tekniker som visadesig vara av särskilt intresse var pH-reglering av avloppsverk, CO2 som näringssubstratför odling av mikroalger, samt tillverkning av kolsyreis för kyltransporter. Samtliga dessatekniker har tillräckligt hög teknisk mognadsgrad för att kunna installeras i dagsläget. AndraCCU-tekniker, såsom ”Power to gas”, kräver en hög CO2-koncentration och avfärdades dålitteraturstudien inte talade för den ekonomiska potentialen i dessa eftersom de kräver ytterligareuppgraderingssteg för CO2. Således valdes istället CCU-tekniker som skulle gå attimplementera direkt med den befintliga CO2 kvalitén. Vidare drogs slutsatsen att en anledningtill att CCU-tekniker inte har blivit vida implementerade till stor del är interna hindermellan distributörer och tillverkare (eller utnyttjare) av CCU-tekniker. Således kan användandetav koldioxid från biogasproduktion och implementering av CCU-tekniker främjasgenom att eliminera hinder hos företag. I projektet yttrade sig detta som bristande ekonomiskaincitament och okunskap. Ett ökat användande av CCU-tekniker kan också uppnås genomatt införa lagar och regler som begränsar användandet av föråldrade tekniker som drivs avfossila bränslen, och som kan ersättas av klimatvänliga CCU-tekniker.

La réduction des émissions de CO2 dans l'atmosphère est primordiale afin d'accomplir la transition écologique. Le stockage géologique du CO2 est un instrument essentiel parmi les stratégies de capture et de stockage du CO2. Les simulations numériques fournissent la solution aux équations de l'écoulement multiphasique qui modélisent le comportement du site d'injection de CO2. Elles constituent un outil essentiel pour décider de l'exploitation ou non d'un site potentiel de stockage de CO2. Cependant, les simulations numériques d'écoulement en milieu poreux sont exigeantes en termes de calcul : il peut falloir plusieurs heures sur un cluster HPC pour simuler un scénario d'injection pour un grand réservoir de CO2 afin de modéliser avec précision les processus physiques complexes impliqués. En particulier, les événements liés aux puits (ouvertures et fermetures) posent d'importantes difficultés numériques en raison de leurs impacts immédiat sur le système. Cela force souvent une réduction drastique de la taille du pas de temps afin de résoudre le système d'équations non-linéaires résultant de la discrétisation du modèle mathématique continu. Cependant, ces événements spécifiques liés aux puits sont relativement similaires dans l'espace et le temps : le degré de similitude entre deux événements de puits dépend de quelques paramètres tels que le débit d'injection, l'état du réservoir au moment de l'événement, les conditions aux limites ou les paramètres du milieu poreux (perméabilité et porosité) autour de chaque puits. L'intérêt récent pour l'application de l'apprentissage automatique à la prédiction des processus physiques a stimulé le développement de la ''Physics Informed Deep Learning'' (PIDL), où les modèles d'apprentissage automatique remplacent ou complètent les algorithmes numériques traditionnels tout en préservant les contraintes inhérentes au modèle physique. Par conséquent, l'objectif de cette thèse est d'adapter les avancées récentes en PIDL afin de réduire l'impact des événements de puits dans la simulation numérique des écoulements multiphasiques en milieux poreux. Nos principales contributions sont divisées en trois parties. Dans la première partie, nous remplaçons le solveur numérique traditionnel par un modèle d'apprentissage automatique. Nous montrons qu'il semble possible d'apprendre des opérateurs 'parameter-to-solution' pour les problèmes d'équations aux dérivées partielles. Cependant, lorsque nous utilisons le modèle d'apprentissage automatique afin d'itérer en temps, la solution prédite s'éloigne de la solution réelle. De ce fait, dans la deuxième partie, nous utilisons une approche hybride, qui complète le solveur non-linéaire traditionnel avec un modèle d'apprentissage automatique, tout en préservant les garanties numériques. En pratique, nous utilisons la méthode de Newton hybride, qui consiste à prédire une initialisation globale pour la méthode de Newton plus proche de la solution que l'initialisation standard. Le Fourier Neural Operator est utilisé comme modèle prédictif. Notre méthodologie est appliquée à deux cas tests et présente des résultats prometteurs en réduisant jusqu'à 54% le nombre d'itérations de Newton par rapport à une méthode de référence. Dans la dernière partie, nous appliquons la méthode de Newton hybride pour prédire une initialisation dans la région proche du puits, où se situent les principales variations de saturations en CO2. Nous étudions d'abord l'impact de la taille du domaine local et démontrons ensuite, sur un cas 1D, qu'il est possible d'apprendre une initialisation locale précise pour n'importe quel emplacement de puits. Nous appliquons ensuite cette approche locale à un cas 2D et comparons les performances entre la stratégie hybride de Newton et une stratégie inspirée de la décomposition de domaine. Nous accélérons la gestion des événements de puits d'environ 45% en termes d'itérations de Newton
The reduction of CO2 emission into the atmosphere is mandatory to achieve ecological transition. CO2 geological storage is an essential instrument for efficient Carbon Capture and Storage (CCS) policies. Numerical simulations provide the solution to the multi-phase flow equations that model the behavior of the CO2 injection site. They are an important tool to decide either or not to exploit a potential carbon storage site and to monitor the operations (potential gas leakage, optimal positioning of CO2 injection wells, etc.). However, numerical simulations of fluid flow in porous media are computationally demanding: it can take up to several hours on a HPC cluster in order to simulate one injection scenario for a large CO2 reservoir if we want to accurately model the complex physical processes involved.parMore specifically, well events (opening and closure) cause important numerical difficulties due to their instant impact on the system. This often forces a drastic reduction of the time step size to be able to solve the non-linear system of equations resulting from the discretization of the continuous mathematical model. However, these specific well events in a simulation are relatively similar across space and time: the degree of similarity between two well events depends on a few parameters such as the injection condition, the state of the reservoir at the time of the event, the boundary conditions or the porous media parameters (permeability and porosity) around each well. Recent interest in machine learning applied to the prediction of physical processes has fueled the development of ''Physics Informed Deep Learning'', where machine learning models either replace or complement traditional numerical algorithms while preserving the inherent constraints from the physical model. Therefore, the objective of this thesis is to adapt recent advances in physics informed deep learning in order to alleviate the impact of well events in the numerical simulation of multiphase flow in porous media. Our main contributions are separated in three parts.parIn the first part, we replace the traditional numerical solver with a machine-learning model. We demonstrate the feasibility of learning parameter-to-solution operators for partial differential equation problems. However, when utilizing the machine-learning model for time iteration, we observe that the predicted solution diverges from the true solution. Consequently, in the second part, we use an hybrid approach that complements the traditional non-linear solver with a machine-learning model while preserving numerical guarantees. In practice, we utilize and tailor to our purpose the hybrid Newton methodology, which involves predicting a global initialization for Newton's method closer to the solution than the standard one. We use the state-of-the-art Fourier Neural Operator machine-learning model as a predictive model. Our methodology is applied to two test cases and exhibits promising results by reducing up to 54% the number of Newton iterations compared to a reference method.parIn the last part, we apply the hybrid Newton methodology to predict an initialization in the near-well region, where the main variations of CO2 saturations occur. We investigate the impact of the local domain size and then demonstrate, for a 1D case, that it is possible to learn a local initialization for any well location. Then, we apply this local approach to a 2D case and compare the performances between the hybrid Newton strategy and a Domain Decomposition-inspired strategy. We speed up the handling of well events by around 45% in terms of Newton iterations

The Internet was originally designed to be a next-generation phone system that could withstand a Soviet attack. Today, we ask the Internet to perform tasks that no longer resemble phone calls in the face of threats that no longer resemble Soviet bombardment. However, we have come to rely on names that can be subverted at every level of the stack or simply be allowed to rot by their original creators. It is possible for us to build networks of content that serve the content distribution needs of today while withstanding the hostile environment that all modern systems face. This dissertation presents the Cryptographically Curated File System (CCFS), which offers five properties that we feel a modern content distribution system should provide. The first property is Strong Links, which maintains that only the owner of a link can change the content to which it points. The second property, Permissionless Distribution, allows anyone to become a curator without dependence on a naming or numbering authority. Third, Independent Validation arises from the fact that the object seeking affirmation need not choose the source of trust. Connectivity, the fourth property, allows any curator to delegate and curate the right to alter links. Each curator can delegate the control of a link and that designee can do the same, leaving a chain of trust from the original curator to the one who assigned the content. Lastly, with the property of Collective Confidence, trust does not need to come from a single source, but can instead be an aggregate affirmation. Since CCFS embodies all five of these properties, it can serve as the foundational technology for a more robust Web. CCFS can serve as the base of a web that performs the tasks of today’s Web, but also may outperform it. In the third chapter, we present a number of scenarios that demonstrate the capacity and potential of CCFS. The system can be used as a publication platform that has been re-optimized within the constraints of the modern Internet, but not the constraints of decades past. The curated links can still be organized into a hierarchical namespace (e.g., a Domain Naming System (DNS)) and de jure verifications (e.g., a Certificate Authority (CA) system), but also support social, professional, and reputational graphs. This data can be distributed, versioned, and archived more efficiently. Although communication systems were not designed for such a content-centric system, the combination of broadcasts and point-to-point communications are perfectly suited for scaling the distribution, while allowing communities to share the burdens of hosting and maintenance. CCFS even supports the privacy of friend-to-friend networks without sacrificing the ability to interoperate with the wider world. Finally, CCFS does all of this without damaging the ability to operate search engines or alert systems, providing a discovery mechanism, which is vital to a usable, useful web. To demonstrate the viability of this model, we built a research prototype. The results of these tests demonstrate that while the CCFS prototype is not ready to be used as a drop-in replacement for all file system use cases, the system is feasible. CCFS is fast enough to be usable and can be used to publish, version, archive, and search data. Even in this crude form, CCFS already demonstrates advantages over previous state-of-the-art systems. When the Internet was designed, there were relatively fewer computers that were far weaker than the computers we have now. They were largely connected to each other over reliable connections. When the Internet was first created, computing was expensive and propagation delay was negligible. Since then, the propagation delay has not improved on a Moore’s Law Curve. Now, latency has come to dominate all other costs of retrieving content; specifically, the propagation time has come to dominate the latency. In order to improve the latency, we are paying more for storage, processing, and bandwidth. The only way to improve propagation delay is to move the content closer to the destination. In order to have the content close to the demand, we store multiple copies and search multiple locations, thus trading off storage, bandwidth, and processing for lower propagation delay. The computing world should re-evaluate these trade-offs because the situation has changed. We need an Internet that is designed for the technologies used today, rather than the tools of the 20th century. CCFS, which regards the trade-off for lower propagation delay, will be better suited for 21st-century technologies. Although CCFS is not preferable in all situations, it can still offer tremendous value. Better robustness, performance, and democracy make CCFS a contribution to the field. Robustness comes from the cryptographic assurances provided by the five properties of CCFS. Performance comes from the locality of content. Democracy arises from the lack of a centralized authority that may grant the right of Free Speech only to those who espouse rhetoric compatible with their ideals. Combined, this model for a cryptographically secure, content-centric system provides a novel contribution to the state of communications technology and information security.

Thesis (MScAgric)--Stellenbosch University, 2012.
ENGLISH ABSTRACT: Plant carotenoid cleavage dioxygenases (CCD) are a family of enzymes that catalyse the oxidative cleavage of carotenoids and/or apocarotenoids. Carotenoids are synthesised in plastids (primarily chloroplasts and chromoplasts), where they are involved in light-harvesting and protecting the photosynthetic apparatus from photo-oxidation. The carotenoid-derived apocarotenoids fulfil a number of roles in plants such as phytohormones, pollinator attractants and flavour and aroma compounds. Due to the floral and fruity characteristics that apocarotenoids contribute to wine, these C13 compounds have received interest in grapevine (Vitis vinifera L.). The CCD gene family in Arabidopsis consists of nine members, all encoding for enzymes that catalyse the cleavage of carotenoids. The enzymes in this family include 9-cis-epoxydioxygenases (NCEDs) and four classes of CCD. NCEDs and CCD7 and CCD8 are involved with plant hormone synthesis, e.g. abscisic acid (ABA) through cleavage by NCED and strigolactone (SL) through the sequential cleavage of carotenoids by CCD7 and CCD8, respectively. SLs are a fairly new class of plant hormone which are involved in several aspects of plant growth and development. The most extensively characterised role of SLs is their involvement in the inhibition of shoot-branching. CCD1 and CCD4 cleave a variety of carotenoids to form pigments and aroma compounds. For example, CCD1 forms β-ionone and β-damascenone, which are important varietal flavours of wine, and CCD4 is involved in synthesis of the pigment and aroma compounds of saffron and annatto. CCD1 enzymes symmetrically cleave the 9,10 (9’,10’) double bonds of multiple carotenoids to produce a C14 dialdehyde and two C13 products. Additional CCD1 cleavage activity at 5,6 (5’,6’) double bonds of lycopene has been reported. Previous studies have shown that CCD1 isolated from V. vinifera (VvCCD1) was able to cleave multiple carotenoid substrates in vitro, namely zeaxanthin, lutein and β-carotene at 9,10 (9’,10’) double bonds and both the 5,6 (5’,6’) and 9,10 (9’,10’) double bonds of lycopene. None of the other VvCCDs, except VvCCD4a have been isolated (but no functionality was illustrated) and characterised yet. CCD4 enzymes also cleave carotenoids at the 9,10 (9’,10’) double bond positions. The presence of plastid-target peptides implies that the CCD4 enzymes have continuous access to carotenoids. Therefore it is suggested that CCD4s are responsible for carotenoid maintenance, where CCD1s contribute towards volatile production. To test this hypothesis VvCCD1, VvCCD4a and VvCCD4b were isolated from V. vinifera (cv Pinotage) cDNA and cloned into a pTWIN1 protein expression vector. Substrate specificity of each VvCCD was tested by co-transforming a carotenoid accumulating E. coli strain with a CCD expression vector. Carotenoids synthesized by the bacteria were identified and quantified by UPLC-analysis, while the concentration of the apocarotenoids, were measured in the headspace of the bacterial cultures using HS-SPME-GC-MS. Several optimisations were done to minimize the natural degradation of the carotenoids; to ensure that the apocarotenoid formation is predominantly due to the enzymatic cleavage by the VvCCDs and not due to oxidation or other non-enzymatic degradation. The HS-SPME-GC-MS analysis indicated that all isoforms cleaved phytoene, lycopene and ε-carotene. Additionally VvCCD1 cleaved a carotenoid involved in photosynthesis, namely β-carotene, while VvCCD4a cleaves neurosporene and VvCCD4b cleaves neurosporene and ζ-carotene, carotenoids not involved in photosynthesis. This study has illustrated that VvCCD1 cleave carotenoids necessary for photosynthesis and VvCCD4s cleave carotenoids which were not present in berry tissue, suggesting their role in carotenoid maintenance. Therefore in planta substrates for CCD1 could possibly be C27 apocarotenoids generated from enzymatic cleavage through CCD4 (role in carotenoid maintenance), CCD7 and/or photo-oxidation, which are then transported from the plastid to the cytosol or possibly C40 carotenoids that are released during senescence or when the plastid membrane is damaged, thus releasing important aroma compounds. Thus the identification of the in vivo substrates has contributed to the understanding the in planta functions of these enzymes
AFRIKAANSE OPSOMMING: Die plant ensiemfamilie van karotenoïedsplitsingdioksigenases (CCDs) kataliseer die oksidatiewe splitsing van karotenoïede en/of apokarotenoïede. Karotenoïede word in plastiede (primêr chloroplaste en chromoplaste) sintetiseer en is betrokke by lig-absorpsie en die beskerming van die fotosintetiese apparaat teen foto-oksidasie. Die apokarotenïede afkomstig van karotenoïede dien onder meer as planthormone, geur- en aromakomponente en om bestuiwers aan te lok. Aangesien apokarotenoïede bydra tot die vrug- en blomgeure van wyn is die C13-verbindings binne wingerd (Vitis vinifera L.) van belang. Al nege lede van die CCD geenfamilie in Arabidopsis kodeer karotenoïedsplitsingsensieme. Die ensiemfamilie sluit 9-sis-epoksidioksigenases (NCEDs), en vier klasse CCD in. NCEDs en CCD7 en 8 is betrokke by die sintese van planthormone, naamlik absissiensuur (ABA) deur NCED en strigolaktone (SL) deur die opeenvolgende aksie van onderskeidelik CCD7 en CCD8. SLe is redelik onlangs as planthormone indentifiseer en is betrokke by ‘n verskeie aspekte van die groei en ontwikkeling van plante. Die rol van SL in inhibisie van vertakking is die beste gekarakteriseerde van hierdie aspekte. CCD1 en CCD4 splits ‘n verskeidenheid karotenoïede om pigmente en aromakomponente te vorm. CCD1 vorm byvoorbeeld β-jonoon en β-damasenoon, beide belangrike kultivar-spesifieke wyngeure. CCD4 vorm weer die pigment en aromakomponente van saffraan en annatto. Die CCD1 ensieme splits die 9,10 (9’,10’) dubbelbindingsetels van verskeie karotenoïede simmetries en vorm een C14-dialdehied en twee C13-produkte. Daar is voorheen melding gemaak van verdere splitsing deur CCD1 by die 5,6 (5’,6’) dubbelbindingsetels van likopeen. Vroeër is getoon dat die CCD1 isovorm wat uit V. vinifera geïsoleer is, naamlik VvCCD1, in vitro seaxantin, luteïen en β-karoteen by die 9,10 (9’,10’) dubbelbindingsetels kon splits, en likopeen by beide die 9,10 (9’,10’) en 5,6 (5’,6’) dubbelbindingsetels. Geen ander VvCCDs is al isoleer en funksioneel gekarakteriseer. VvCCD4a is isoleer, maar geen funksie is bepaal nie. CCD4 ensieme splits ook die 9,10 (9’,10’) dubbelbindingsetels van karotenoïede. Aangesien CCD4 ensieme ‘n plastied-bestemmingspeptied besit behoort dié ensieme konstant toegang tot karotenoïede te hê, wat dui op hul rol in die handhawing van die karotenoïedbalans, terwyl CCD1-ensieme bydra tot die sintese van vlugtige verbindings. Om hierdie hipotese te toets is VvCCD1, VvCCD4a en VvCCD4b uit V. vinifera (kv Pinotage) kDNS isoleer in binne ‘n pTWIN1 proteïenuitdrukkingsvektor kloneer. Die substraatspesifisiteit van elke VvCCD is getoets deur ‘n karotenoïedakkumulerende E. coil stam te transvormeer met ‘n CCD-uitdrukkingsvektor. UPLC-analise is gebruik om karotenoïede wat deur die bakterium sintetiseer is te kwantifiseer en identifiseer, terwyl die apokarotenoïedinhoud en -konsentrasie van die boruimte van die bakteriële kultuur met HS-SPME-GC-MS bepaal is. Verskeie aspekte van die proses is optimaliseer om natuurlike afbreking van karotenoïede te minimeer. Daardeur is verseker dat die apokarotenoïedvorming primêr vanweë die ensiematiese splitsing deur VvCCDs plaasvind en nie deur oksidasie of ander nie-ensiematiese afbreking. Die HS-SPME-GC-MS metings het aangedui dat al drie isovorme fitoëen, likopeen en ε-karoteen kan splits. VvCCD1 kan daarby β-karoteen splits, terwyl VvCCD4a neurosporeen, en VvCCD4b neurosporeen en ζ-karoteen kan splits, beide karotene wat nie betrokke is by fotosintese nie. Dié studie toon dat VvCCD1 die karotenoïede splits wat benodig word vir fotosintese, terwyl beide VvCCD4 isovorme karotenoïede splits wat nie in druiwekorrels gevind word nie. Dit dui op hulle rol in die handhawing van karotenoïedpoele. Die in planta substrate vir CCD1 mag dus die C27-apokarotenoïede wees wat deur CCD4 (as deel van karotenoïedhandhawing), CCD7 en/of foto-oksidasie gevorm word en na die sitosol vervoer word, of moontlik die C40-karotenoïede wat tydens veroudering óf wanner die plastiedmembraan beskadig is in die sitosol vrygestel word. Die identifisering van die in vivo substrate het dus bygedra to die begrip van die in planta funksies van die ensieme.

CCS (Communicating and Concurrent Systems) is the process algebra to specify and verify concurrent and communicating systems. This work proposes a transformation guide of the CCS equations into to the UML-RT (Unified Modeling Language for Real-Time) model and a transformation guide of the UML-RT model into a set of CCS equations. The UML-RT model is a software design language, which supports code generation and the construction of executable systems. The UML-RT is an UML extension, and it does not have a formal semantics; therefore it is not possible to verify UMLRT models. The transformation guide of UML-RT models into CCS equations allows verifying the models. We argue that the transformation of CCS models into UML-RT models allows an alternative way of correctly building systems. This work details the transformation guides from CCS equations to UML-RT models and from UML-RT models to CSS equations and it discusses the limitations and benefits.

Design: Prospective retrolective study. Setting: 11 National Health Service cleft centres. Participants: The frontal facial photographs of239 five year old children with nonsyndromic UCLP from the 1998 CSAG survey were collected, along with the frontal and worm's eye view (WEV) photographs of252 five year old children with nonsyndromic UCLP from the current CCUK survey. The children in the CSAG group having been treated pre-centralisation and those in the CCUK cohort treated post centralisation. Main Outcome Measures: The main outcome measure was an aesthetic rating using a categorical five point Likert scale rating of the frontal and the WEV photographs. Methods: All photographs were cropped to include the nasolabial region only. The photographs were arranged randomly within a web-based aesthetic scoring tool. The aesthetic appearance of 742 photographs (239 CSAG frontals, 252 CCUK frontals and 251 CCUK WEVs) were assessed by 6 raters using a categorical 5-point Likert type scale over a 3 week period. Each rater repeated the scoring of 10% of the photographs 4 weeks after the initial assessment stage to allow analysis of inter- and intra-rater reliability . Results: The overall level of agreement between the members of the assessment panel when rating the frontal views in both the CSAG group and the CCUK group was fair. Assessment of facial appearance of the CCUK group using WEV s showed a poor agreement between the examiners. The results showed a good overall agreement within the examiners assessing both the pooled frontal views (CSAG and CCUK) and WEVs (CCUK). There was a poor agreement within the examiners assessing the same subjects using 2 different views i. e. frontal and WEV s in the CCUK group. Overall the odds ratio shows that there was evidence that outcomes had improved in CCUK group relative to the CSAG group. Conclusion: The impact of the new centralised cleft care showed a better facial appearance outcome compared to the original CSAG survey.

Sverige har som ambition att uppnå nettonollutsläpp av fossilt CO2 till år 2045. För att lyckas med detta ska landet minska sina utsläpp med 85%, samtidigt som så kallade kompletterande åtgärder kommer vidtas för att kompensera för resterande 15%. Denna studie utreder Sveriges arbete med negativa utsläpp som kompletterande åtgärd med fokus på teknikerna bio-energy for carbon capture and storage (Bio-CCS på svenska), Direct air capture for carbon capture and storage (DACCS) och biokol. Även carbon capture and storage (CCS), som kan bidra till att göra anläggningar CO2-neutrala, har studerats. Under arbetets gång har en litteraturstudie samt intervjuer med forskare, politiker, bransch- och företagsrepresentanter samt myndigheter genomförts.  För CCS och Bio-CCS, som innefattar avskiljning av CO2 från punktutsläpp, finns fyra olika avskiljningsstrategier som kallas post-, pre-, och oxyfuel combustion samt chemical looping. I fallet med DACCS tillämpas antingen absorption eller adsorption för att avskilja koldioxiden från atmosfären. Biokol produceras genom förbränning av biomassa i en pyrolysanläggning och kan sedan användas som jordförbättringsmedel och kolsänka. Det finns idag en inhemsk biokolsproduktion på kommersiell skala vilket gör att biokol skiljer sig från de övriga tre teknikerna som inte kommit lika långt i sin utveckling. Däremot finns det ett flertal pilotprojekt inom CCS och Bio-CCS i Sverige.  Sveriges väletablerade bioekonomi gör att det finns goda förutsättningar för biokol och Bio- CCS att bidra till negativa utsläpp ur ett 2045-perspektiv. DACCS anses däremot inte aktuellt som kompletterande åtgärd till år 2045. Efter intervjuer framgår att det råder en god samstämmighet mellan olika aktörer kring vilka faktorer som behöver behandlas för att implementera teknikerna. Gemensamt för alla tekniker är att det krävs ekonomiska incitament för att möjliggöra storskalig implementering. För CCS-teknikerna krävs även regulatoriska förändringar för att underlätta transporten av CO2.
Sweden's ambition is to achieve net zero emissions of fossil CO2 by the year 2045. To reach this target, Sweden aims to reduce its emissions by 85%, while so-called supplementary measures will be taken to compensate for the remaining 15%. This study investigates Sweden's work with negative emissions as a complementary measure with a focus on the technologies bio-energy for carbon capture and storage (Bio-CCS in Swedish), Direct air capture for carbon capture and storage (DACCS) and biochar. Carbon capture and storage (CCS), which can help make industrial plants CO2-neutral, has also been studied. During the project, a literature study and interviews with researchers, politicians, industry and company representatives as well as authorities were carried out, which formed the basis of the report.  For CCS and Bio-CCS, which include separation of CO2 from point source emissions, there are four different separation strategies called post-, pre-, and oxyfuel combustion as well as chemical looping. Among these, post combustion is highlighted as the most developed. In the case of DACCS, either absorption or adsorption is applied to separate CO2 from the atmosphere. CCS, Bio-CCS and DACCS all have in common that the captured CO2 must be stored in deep geological formations once it has been separated. Biochar is produced by heating biomass in a pyrolysis plant and can be used as a soil improver and carbon sink. Today Sweden has a domestic biochar production on a commercial scale, which means that biochar differs from the other three technologies that have yet to reach that stage of development. However, there are several pilot projects within Bio-CCS and CCS in Sweden.  Sweden's well-established bioeconomy means that the conditions are good for biochar and Bio-CCS to contribute to negative emissions in relation to the 2045 target. DACCS, on the other hand, is not considered relevant as a supplementary measure to the year 2045 due to its technical immaturity and high cost. From interviews with researchers, authorities, companies, industry organizations and politicians, it is clear that there is a consensus between the different actors on which factors need to be addressed in order to enable large-scale implementation of the technologies. Common to all technologies is that financial incentives are required to enable large-scale implementation. The CCS technologies also require regulatory changes to facilitate the transport of CO2.

Cuaderno de trabajo de química general y orgánica para ciencias de la salud, que corresponde al ciclo 2013-1. Contenido: 1. Conceptos fundamentales. 2. Cambios en la materia. 3. Equilibrio químico. 4. Química de los compuestos orgánicos. 5. Isómeros. 6. Biomoléculas.

A review of X-ray telescope focal-plane instrumentation is given. The architectures and operating principles of contemporary charge-coupled device (CCD) imagers are discussed. The fabrication of CCDs manufactured by EEV Ltd. is described. An overview of a slow-scan CCD evaluation system is given and the design, construction and operation of a microcomputer controlled programmable CCD readout sequencer is detailed. The technique of on-chip pixel binning is discussed. CCD noise sources and noise measurement techniques are reviewed and constructional details of a low noise analogue CCD signal processor are presented. A description of CCD data processing and image display software is given. The results of X-ray efficiency and energy resolution measurements on standard and specially developed deep-depletion CCDs are presented and accounted for. It is shown that deep-depletion devices can be fabricated to offer energy resolution equal with that of standard devices, together with superior detection efficiencies. Both device types are shown to give spectral resolution comparable with that obtained from other silicon-based detectors. Aspects of CCD operation in the space environment are considered and the relevance of this work to the development of CCD instrumentation for the European Space Agency's XMM satellite is assessed. In conclusion, the important characteristics of standard and deep-depletion CCDs are noted and areas thought to require further investigation are highlighted.

The main objective of this work it to produce membrane electrode assemblies (MEAs) that have improved performance over MEAs produced by the conventional manner, by producing highly efficient, electroactive, uniform catalyst layers with lower quantities of platinum electrocatalyst. The catalyst coated membrane (CCM) method was used to prepare the MEAs for the PEM fuel cell as it has been reported that this method of MEA fabrication can improve the performance of PEM fuel cells. The MEAs performances were evaluated using polarisation studies on a single cell. A comparison of polarisation curves between CCM MEAs and MEAs produced in the conventional manner illustrated that CCM MEAs have improved performance at high current densities (>
800 mA/cm2).

El continu increment en l'ús de les energies renovables i els objectius per a la reducció de les emissions de diòxid de carboni (CO2) requereixen canvis significatius tant a nivell tècnic com a nivell normatiu. La captura i utilització de diòxid de carboni (CCU, per les sigles en anglès) és un mètode eficaç per aconseguir la mitigació del CO2 i al mateix temps mantenir de forma segura els subministraments d'energia. Si bé la demanda a la reducció de les emissions de CO2 està augmentant, l'eficiència energètica i el cost dels processos de captura de CO2 segueixen sent un factor limitant per a les aplicacions industrials. En el present treball s'estudia l'ús del procés d'adsorció per oscil·lació de pressió i buit (VPSA, per les sigles en anglès) amb adsorbents d'alta selectivitat per separar el CO2 dels gasos de combustió, com un mètode alternatiu al procés d'absorció tradicional amb amines. Es realitza un estudi preliminar mitjançant Anàlisi Tèrmica per determinar la capacitat d’adsorció i el comportament cíclic de la captura de CO2 per deu adsorbents comercials, inclosos els tamisos moleculars de carboni (CMS) i les zeolites. L'anàlisi es va fer amb CO2 pur, N2 pur i mescles dels dos gasos en la proporció 15%/85% que correspon a la composició d’un gas de combustió normal; s’usen les zeolites comercials 13X, 5A, 4A sense i amb aglomerants i tres tamisos moleculars de carboni (CMS) en l’interval de pressió de 0 a 10 bar i a 283K, 298K, 232K i 323 K de temperatura. Els resultats s’han ajustat amb els models Toth, Sips i Dual Site Langmuir (DSL). Es va realitzar una selecció entre deu adsorbents comercials per a la captura de CO2, inclosos els tamisos moleculars de carbó (CMS, per les sigles en anglès) i les zeolites. Es van determinar les propietats texturals, la capacitat d'adsorció i el comportament cíclic dels adsorbents per comparar el seu comportament a la separació del diòxid de carboni del nitrogen. Posteriorment, es van mesurar les isotermes d'adsorció d'un sol component en la balança de suspensió magnètica a quatre temperatures diferents (283, 298, 232 i 323 K) i en un ampli marge de pressions (de 0 a 10 bara). Les dades sobre les isotermes de components purs es van correlacionar utilitzant els models Toth, Sips i Dual Site Langmuir (DSL). Es van dissenyar i construir tres unitats de laboratori per realitzar l'experimentació del procés VPSA. La primera unitat es va usar per a la producció i el control de mescles gasoses de CO2 i N2 a una pressió màxima de 9 bara. En la segona unitat es van dur a terme la determinació dels equilibris d'adsorció amb una barreja de composició semblant a la dels gasos de combustió (15/85% de CO2/N2 v/v). Amb el programa Aspen Adsorption® es va simular el sistema experimental, obtenint que les prediccions del model DSL reprodueixen suficientment bé els resultats experimentals de les corbes de ruptura i els perfils de temperatura en el llit fix. A més, es van fer estudis dinàmics per avaluar les zeolites 5ABL i 13XBL usant el procés VPSA discontinu per a la separació CO2 de N2. La unitat dos es va dotar d'un sistema de control amb una interfície PLC que facilita la seva operació i automatització, usant una estratègia de control desenvolupada en aquest treball. En base als resultats obtinguts amb la unitat dos, tant experimentals com simulats, es va trobar que la zeolita 13XBL era la més adequada per al procés VPSA proposat. Els resultats experimentals es van emprar per alimentar el disseny de la unitat dos a Aspen Adsorption® i validar el model usat que al seu torn es va utilitzar per realitzar un disseny complet d'experiències de dos factors (26) en configuració continua. La tercera unitat experimental consta de tres columnes d'adsorció on es va incloure l'estratègia de control desenvolupada per la unitat dos i es va incloure la recirculació dels corrents rics en N2 i CO2. Es van dur a terme tres experiments del procés VPSA cíclic de 8 passos canviant els paràmetres de control del procés automatitzat i usant la zeolita 13XBL com adsorbent. Es va aconseguir satisfer els objectius en termes puresa de CO2 (> 80%) i consum energètic (<2.5 kWh/kgCO2). Sobre la base dels resultats experimentals i simulats, es va realitzar una demostració a escala pilot de la captura de CO2 del gas de combustió d'una caldera de vapor en una planta industrial a situada a la província de Barcelona.La planta pilot de captura de CO2 consta d'un procés de pretractament dels gasos de combustió, una unitat VPSA acoblada amb una unitat de deshumidificació i una aplicació industrial per a l'ús del CO2. A la unitat de pretractament, els gasos de combustió es van refredar de 70ºC a 25ºC i es van desnitrificar. A la unitat de deshumidificació, es va eliminar el vapor d'aigua del gas desnitrificat mitjançant adsorció sobre alúmina. Posteriorment, es va emprar el procés VPSA de vuit passos amb tres columnes usant zeolita 13XBL, en la qual es va obtenir un corrent enriquit de CO2 de 85 a 95% de puresa de CO2, amb una recuperació del 48 a 56%, una productivitat de 0,20-0,25 gCO2/(gads·h) i un consum energètic de 1.48 kWh/kgCO2. El CO2 recuperat es va usar per reemplaçar l'ús d'àcids minerals en l'etapa de regulació del pH de la planta de tractament d'aigües residuals existent a la fàbrica. Per tant, el procés desenvolupat és una alternativa efectiva per separar el CO2 dels punts d'emissió de gasos de combustió industrial i utilitzar el CO2 recuperat com a matèria primera per a aplicacions industrials. L'ús de CO2 capturat en aquestes fonts d'emissió té dos avantatges clars. D'una banda, es van reduir les emissions de CO2 a la atmosfera. De l'altra, va permetre reutilitzar i transformar un contaminant ambiental en compostos neutres.
El continuo incremento en el uso de las energías renovables y los objetivos para la reducción de las emisiones de dióxido de carbono (CO2) requieren cambios significativos tanto a nivel técnico como a nivel normativo. La captura y utilización de dióxido de carbono (CCU, por sus siglas en inglés) es un método eficaz para lograr la mitigación del CO2 y al mismo tiempo mantener de forma segura los suministros de energía. Si bien la demanda en la reducción de las emisiones de CO2 está aumentando, la eficiencia energética y el costo de los procesos de captura de CO2 siguen siendo un factor limitante para las aplicaciones industriales. En el presente trabajo se estudia el uso del proceso de adsorción por oscilación de presión y vacío (VPSA, por sus siglas en inglés) con adsorbentes de alta selectividad para separar el CO2 de los gases de combustión, como un método alternativo al proceso de absorción tradicional con aminas. Se realizó una selección entre diez adsorbentes comerciales para la captura de CO2, incluidos los tamices moleculares de carbón (CMS, por sus siglas en inglés) y las zeolitas. Se determinaron las propiedades texturales, la capacidad de adsorción y el comportamiento cíclico de los adsorbentes para comparar su comportamiento en la separación del dióxido de carbono del nitrógeno. Posteriormente, se midieron las isotermas de adsorción de un solo componente en la balanza de suspensión magnética a cuatro temperaturas diferentes (283, 298, 232 y 323 K) y en un amplio margen de presiones (de 0 a 10 bara). Los datos sobre las isotermas de componentes puros se correlacionaron utilizando los modelos Toth, Sips y Dual Site Langmuir (DSL). Se diseñaron y construyeron tres unidades de laboratorio para realizar la experimentación del proceso VPSA. La primera unidad se usó para la producción y el control de mezclas gaseosas de CO2 y N2 a una presión máxima de 9 bara. En la segunda unidad se llevaron a cabo las mediciones de los equilibrios de adsorción con una mezcla de composición semejante a la de los gases de combustión (15/85% de CO2/N2 v/v). Con el programa Aspen Adsorption® se simuló el sistema experimental, obteniendo que las predicciones del modelo DSL reproducen suficientemente bien los resultados experimentales de las curvas de ruptura y los perfiles de temperatura en el lecho fijo. Además, se hicieron estudios dinámicos para evaluar las zeolitas 5ABL y 13XBL usando el proceso VPSA discontinuo para la separación CO2 de N2. La unidad dos se dotó de un sistema de control con una interfaz PLC que facilita su operación y automatización, usando una estrategia de control desarrollada en este trabajo. En base a los resultados obtenidos con la unidad dos y su simulación, se encontró que la zeolita 13XBL era la que la más adecuada para el proceso VPSA propuesto. Los resultados experimentales se usaron para alimentar el diseño de la unidad dos en Aspen Adsorption® y validar el modelo usado que a su vez se utilizó para realizar un diseño completo de experiencias de dos factores (26) en configuración discontinua. La tercera unidad experimental consta de tres columnas de adsorción donde se incluyó la estrategia de control desarrollada para la unidad dos y se incluyó la recirculación de las corrientes ricas en N2 y CO2. Se llevaron a cabo tres experimentos en el proceso VPSA cíclico de 8 pasos cambiando los parámetros de control del proceso automatizado y usando la zeolita 13XBL como adsorbente. Se logró satisfacer los objetivos en términos pureza de CO2 (>80%) y consumo energético (<2.5 kW·h/kgCO2). Sobre la base de los resultados experimentales y simulados, se realizó una demostración a escala piloto de la captura de CO2 del gas de combustión de una caldera de vapor en una planta industrial situada en la provincia de Barcelona. La planta piloto de captura de CO2 consta de un proceso de pretratamiento de los gases de combustión, una unidad VPSA acoplada con una unidad de deshumidificación y una aplicación industrial para el uso del CO2. En la unidad de pretratamiento, los gases de combustión se enfriaron de 70ºC a 25ºC y desnitrificaron. En la unidad de deshumidificación, se eliminó el vapor de agua del gas desnitrificado mediante adsorción con alúmina. Posteriormente, se empleó el proceso VPSA de ocho pasos con tres columnas usando zeolita 13XBL, en la que se obtuvo una corriente enriquecida de CO2 de 85 a 95% de pureza de CO2, con una recuperación del 48 a 56%, una productividad de 0.20 a 0.25 gCO2/(gads٠h-) y un consumo energético de 1.48 kWh/ kgCO2. El CO2 recuperado se usó para reemplazar el uso de ácidos minerales en la etapa de regulación del pH de la planta de tratamiento de aguas residuales existente en la fábrica. Por lo tanto, el proceso desarrollado es una alternativa efectiva para separar el CO2 de los puntos de emisión de gases de combustión industrial y utilizar el CO2 recuperado como materia prima para aplicaciones industriales. El uso de CO2 capturado en estas fuentes de emisión tiene dos ventajas claras. Por un lado, redujeron las emisiones de CO2 a la atmósfera. Por otro lado, permitió reutilizar y transformar un contaminante ambiental en compuestos neutros.
The continuously increasing share of renewable energy sources and European Union targets for carbon dioxide (CO2) emission reduction need significant changes both on a technical and regulatory level. Carbon dioxide capture and utilization (CCU) is an effective method for achieving CO2 mitigation while simultaneously keeping energy supplies secure. While the demand for reduction in CO2 emissions is increasing, the improvement of energy-efficiency and the cost of CO2 capture processes remains a limiting factor for industrial applications. The present work studies the Vacuum Pressure Swing Adsorption process (VPSA) using high selectivity adsorbents for separating CO2 from flue gas as an alternative method to the traditional absorption process with amines. A screening analysis for CO2 capture was conducted on ten commercial adsorbents, including carbon molecular sieves (CMS) and zeolites. The textural properties, the adsorption capacities and the adsorbent cyclic behaviors were determined to compare their performance in the context of CO2 separation from nitrogen (N2). Subsequently, the single component adsorption isotherms were measured in a magnetic suspension balance at four different temperatures (283, 298, 232 and 323 K) and over a large range of pressures (from 0 to 10 bara). Data on the pure component isotherms were correlated using the Toth, Sips and Dual Site Langmuir (DSL) models. Three laboratory units were designed and built to perform the VPSA experiments. The first was used for the production and control of CO2 and N2 gas mixtures at a maximum pressure of 9 bara. Adsorption equilibrium measurements with a mixture that resembles the composition of combustion gases (15/85% CO2/N2 v/v) were obtained using the second unit that was built. Afterwards, the Aspen Adsorption® program was used to simulate the experimental system, where the predictions of the DSL model agree with the breakthrough curves and the temperature profiles of the experimental fixed bed results. In addition, dynamic studies were performed to evaluate the zeolites 5ABL and 13XBL using a discontinuous VPSA process for the CO2 separation of N2. The process was automated and operated with a PLC interface, using a control strategy developed in this work. Based on the comparison results of the zeolites, it was found that the 13XBL zeolite was the one most suitable for the proposed VPSA process. The experimental results were verified by numerical simulations in the Aspen Adsorption® software and the validated model was used to perform a two-factor complete design of experiments (26) using 13XBL simulations in a discontinuous configuration. The third experimental unit was built with three adsorption columns which included the developed control strategy and the recirculation of N2 and CO2 rich streams. Three experiments were carried out using zeolite 13XBL as an adsorbent for the proposed 8-step VPSA cyclic process by changing the control parameters of the automated process. Through the experiments, the objectives were achieved in terms of CO2 purity (> 90%) and energy consumption (> 2.5 kWh/kgCO2). Based on the experimental and simulated results, a pilot-scale demonstration plant for CO2 capture from flue gas in an existing industrial boiler in a Spanish company was carried out. The pilot-scale CO2 capture plant consisted of a pre-treatment process for flue gases, a VPSA unit coupled with a dehumidification unit and an industrial application for the use of CO2. In the pretreatment unit the flue gases were cooled from 70°C to 25°C and then denitrified. In the dehumidification unit, the water vapor was removed from the denitrified gas by adsorption with alumina. Subsequently, the three columns’ eight-step VPSA process developed with zeolite 13XBL was used. The results were a product purity of 85 to 95% of CO2, a recovery of 48 to 56%, a productivity of 0.20 to 0.25 gCO2/(gads٠h) and an energy consumption of 1.48 kWh/kgCO2. The recovered CO2 was then used to replace the use of mineral acids in the pH regulation stage of the existing wastewater treatment plant. Therefore, it is concluded that the developed process is an effective alternative to separate the CO2 from the emission points of industrial combustion gases and to use the recovered CO2 as raw material for industrial applications. The use of CO2 captured in these emission sources has two clear advantages. On the one hand, it reduces the CO2 emissions to the atmosphere. On the other hand, it allows the reuse and transformation of an environmental pollutant into neutral compounds.

CO2 emissions from the combustion of fossil fuels are the largest sources of anthropogenic greenhouse gas emissions to the atmosphere. Carbon capture and storage (CCS) is one of the better options to mitigate these emissions and thereby limit global warming even while continuing the use of fossil fuels for power generation. As CCS increases the energy consumption of the power plant itself, there will be an increased use of fuel and therefore also increased environmental impacts connected to this. To calculate these impacts it is important to include the entire supply chain and life cycle of the power plant.This thesis involves a tiered hybrid life cycle assessment of natural gas- and coal power plants with chilled ammonia process (CAP) and sorption enhanced water-gas shift (SEWGS) capture technologies. These novel capture technologies are two of the least studied when it comes to environmental assessments. The results from this assessment are compared to two of the more studied capture technologies, post-combustion capture by monoethanolamine (MEA) and oxyfuel combustion capture.Both the CAP capture alternative and the SEWGS alternative have been shown to decrease the global warming potential (GWP) in a natural gas plant by 70%. For the coal-fired power plants, the CAP technology managed a decrease in GWP of 77% while the SEWGS technology showed a decrease of 77.5%. This decrease comes at a cost of other impact categories where for example the freshwater ecotoxicity potential (FETP) has an increase of 87-88% for both the CAP and SEWGS capture technologies in NGCC plants. This impact category has an increase of 25 and 22% for the CAP and SEWGS technologies in the coal-fired power plants.Compared to post-combustion capture by MEA and oxyfuel combustion capture, the results were clear on MEA being the least preferable option in an environmental perspective for both coal- and natural gas-fired power plants. Oxyfuel combustion capture, on the other hand, was shown to be the most preferable option.

The specification and verification of communicating systems has captured increasing interest in the last decades. CCS, a Calculus of Communicating Systems [Milner 89a], was especially designed to help this enterprise; it is widely used in both industry and academia. Most efforts to automate the use of CCS for verification have centered around the explicit construction of a bisimulation [Park 81]. This approach, however, presents severe limitations to deal with systems that contain infinite states (e.g. systems with evolving structure [Milner 89a] or that comprise a finite but arbitrary number of components (e.g. systems with inductive structure [Milner 89a]). There is an alternative approach to verification, based on equational reasoning, which does not exhibit such limitations. This formulation, however, introduces significant proof search control issues, and, hence, has remained far less explored. This thesis investigates the use of explicit proof plans [Bundy 88] for problems of automatic verification in the context of CCS. We have conducted the verification task using equational reasoning, and centred on infinite state systems, and parameterised systems. A parameterised system, e.g. a system with inductive structure, circumscribes a family of CCS systems, which have fixed struture and finitely many states. To reason about theses systems, we have adopted Robin Milner's approach [Milner 89a], which advocates the use of induction to exploit the structure and/or the behavior of a system during its verification. To automate this reasoning, wehave used proof plans for induction [Bundy 88]- built within CLAM [Bundy et al 90b], and extended it with special CCS proof plans. We have implemented a verification planner by adding these special proof plans to CLAM. The system handles the search control problems prompted by CCS verification satisfactorily, though it is not complete. Moreover, the system is capable of dealing with the verification of finite state systems, infinite state systems, and parameterised systems, hence, providing a uniform method to analyse CCS systems, regardless of their state space. Our results are encouraging: the verification planner has been successfully tested on a number of examples drawn from the litereature. We have planned proofs of conjectures that are outside the domain of existing verification methods. Furthernore; the verification planning is fully automated. Because of this, even though the verification plan has still got plenty of room for improvement, we can state that proof planning can handle the equational verication of CCS systems, and, therefore, advocate its use within this interesting field.

To decrease global warming, bioenergy with carbon capture and storage (Bio-CCS) has been proposed as an effective and necessary tool. Combusting biomass and capturing carbon dioxide (CO2) from the same process results in net negative emissions, hence, reducing the concentration of CO2 in the atmosphere. The infrastructure around heat and power generation in Sweden has transformed to make use of biomass and waste. Bio-CCS has the potential to be a key factor in making the heat sector carbon negative and the Swedish energy system more sustainable. This study has assessed how Bio-CCS can practically be implemented in the Uppsala heat and power plant. In the assessment, three chemical absorption post-combustion carbon capture (CC) technologies were evaluated based on energy requirement, potential to reduce emissions and economics. They are the amine process, the chilled ammonia process (CAP) and the hot potassium carbonate process (HPC). The process of each technology was modelled by performing mass and energy balance calculations when implementing CC on the flue gas streams of the production units using biomass-based fuel at the plant. The modelling enabled finding specific heating, cooling and electricity requirements of the technologies. With this data it was possible to assess the potential emission reduction and CC cost for the different configurations assessed. A solution was proposed in how a CC technology can be integrated into the system of the Uppsala plant regarding land footprint, available heat supply to the process and possibilities for waste heat recovery. If heat recovery is not utilized the results show that the amine process is the most cost-effective technology when implemented on the flue gas stream of the waste blocks. When utilizing heat recovery to use waste heat to heat the district heating water, CAP becomes more cost-effective than the amine process. Further improvements can be achieved by combining flue gas streams of the waste blocks to increase the number of hours per year CC can be performed. The plant in Uppsala can then capture 200 000 tonne CO2 annually. The total cost of Bio-CCS will be approximately 900 SEK per tonne CO2 captured.
För att minska den globala uppvärmningen har infångning och lagring av koldioxid från förbränning av biomassa (Bio-CCS) föreslagits som ett effektivt och nödvändigt verktyg. Förbränning av biomassa och infångande av koldioxid från samma process leder till negativa nettoutsläpp, vilket minskar koncentrationen av koldioxid (CO2) i atmosfären. Infrastrukturen kring värme- och kraftproduktion i Sverige har omvandlats till att använda biomassa och avfall. Bio-CCS har potential att vara en nyckelfaktor för att göra värmesektorn koldioxidnegativ och det svenska energisystemet mer hållbart. Denna studie har analyserat hur Bio-CCS praktiskt kan implementeras i Uppsalas kraftvärmeverk. I analysen utvärderades tre infångningstekniker av typen kemisk absorption baserat på energibehov, potential att minska utsläpp och ekonomi. Teknikerna är aminprocessen, chilled ammonia process (CAP) och hot potassium carbonate process (HPC). Processen för varje teknik modellerades genom att utföra mass- och energibalansberäkningar vid infångning av CO2 från rökgasströmmarna producerade av produktionsenheterna som förbränner biomassa. Modelleringen gjorde det möjligt att hitta specifika värme-, kyl- och elbehov för teknikerna. Med dessa data var det möjligt att bedöma den potentiella utsläppsminskningen och kostnaden för infångning för de olika konfigurationer som har analyserats. En lösning föreslogs i hur en infångningsanläggning kan integreras i kraftvärmeverkets system när det gäller markanvändning, tillgänglig värmeförsörjning till processen och möjligheter till återvinning av spillvärme. Om värmeåtervinning inte utnyttjas visar resultaten att aminprocessen är den mest kostnadseffektiva tekniken när den implementeras på rökgasströmmen från avfallsblocken. När man använder värmeåtervinning för att använda spillvärme för att värma fjärrvärmevattnet blir CAP mer kostnadseffektivt än aminprocessen. Ytterligare förbättringar kan uppnås genom att kombinera rökgasströmmar från avfallsblocken för att öka antalet timmar per år infångning kan utföras. Anläggningen i Uppsala kan då årligen fånga 200 000 ton CO2. Den totala kostnaden för Bio-CCS kommer att vara cirka 900 SEK per ton infångad CO2.

Thesis (S.M. in Transportation)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2010.
Cataloged from PDF version of thesis.
Includes bibliographical references (p. 115-118).
The objective of this report is to determine whether opportunities to use liquefied carbon dioxide carriers as part of a carbon capture and storage system will exist over the next twenty years. Factors that encourage or discourage the use of vessels are discussed. This study concludes that liquefied carbon dioxide carriers can potentially be used in both the near and long term under different sets of circumstances.
by Mary-Irene Alexandrakis and Bret S. Smart.
S.M.in Transportation

CCS, Carbon Capture and Storage, innebär infångning och lagring av koldioxid från stora punktutsläpp. Detta gör cementindustrin aktuell för implementering av CCS. Stora delar av branschens koldioxidutsläpp går inte att eliminera på annat sätt. Kostnaden för monoetanolamin-baserad post-combustion capture med efterföljande transport och lagring av koldioxiden vid cementfabriken Cementa AB i Degerhamn undersöktes. Studiens kostnadsberäkningar är baserade på publicerade uppgifter om kostnaden för koldioxidinfångning vid den norska cementfabriken Norcem Brevik, och på publicerade uppgifter om kostnaden för transport av koldioxid till en lagringsplats i Östersjön. Cementa Degerhamns koldioxidutsläpp kan reduceras med 5,4 miljoner ton under en 25-årsperiod till en kostnad av 2,2 miljarder SEK. Slutresultatet, som uttrycks i måttet Cost of CO2 avoided, ger en kostnad på 890 SEK/ton CO2. En känslighetsanalys visar att av de undersökta parametrarna är storleken på koldioxidutsläppen och kostnaden för användning och underhåll viktigast för storleken på Cost of CO2 avoided. Vidare studier behövs för en mer exakt beräkning av kostnaden för CCS vid Cementa Degerhamn.
CCS, Carbon Capture and Storage, involves the capture and storage of carbon dioxide from large point sources. This makes the cement industry suitable for the implementation of CCS. Large parts of the industry's carbon dioxide emissions cannot be eliminated by other means. The cost of monoethanolamine-based post-combustion capture and subsequent transport and storage of the carbon dioxide at the cement factory Cementa AB in Degerhamn was studied. This study's cost estimates are based on published data on the cost of carbon capture at the Norwegian cement plant Norcem Brevik, and on published data on the cost of transport of carbon dioxide to a storage site in the Baltic Sea. Cementa Degerhamn’s carbon dioxide emissions can be reduced by 5.4 million tons over a 25 year period to a cost of 2.2 billion SEK. The result, expressed in Cost of CO2 avoided, gives a cost of 890 SEK/ton CO2. A sensitivity analysis shows that of the examined parameters, the size of the carbon dioxide emissions and the cost of use and maintenance are the most important for the size of Cost of CO2 avoided. Further studies are required for a more accurate calculation of the cost of CCS at Cementa Degerhamn.

CSR strategy is not only about unilateral spending of funds on charitable purposes. An effective CSR strategy leads to fulfillment of economic goals of the company. The aim of this thesis is to analyze the current state of CSR in company CCS, s. r. o. and suggest possible improvements, or more precisely, develop an effective and coherent CSR strategy. As a tool for creating strategy are in this thesis primarily used in-depth interviews with employees of HR and marketing teams and models of organization Byznys pro společnost. On the basis of this instruments was created a specific CSR strategy for the company CCS.

I assess the potential of seismic and time-domain controlled-source electromagnetic (CSEM) methods to monitor carbon dioxide (CO2) migration through the application of a monitorability workflow. The monitorability workflow describes a numerical modelling approach to model variations in the synthetic time-lapse response due to CO2 migration. The workflow consists of fluid-flow modelling, rock-physics modelling and synthetic seismic or CSEM forward modelling. I model CO2 injected into a simple, homogeneous reservoir model before applying the workflow to a heterogeneous model of the Bunter Sandstone reservoir, a potential CO2 storage reservoir in the UK sector of the North Sea. The aim of this thesis is to model the ability of seismic and time-domain CSEM methods to detect CO2 plume growth, migration and evolution within a reservoir, as well as the ability to image a migrating front of CO2. The ability to image CO2 plume growth and migration within a reservoir has not been demonstrated in the field of CSEM monitoring. To address this, I conduct a feasibility study, simulating the time-lapse CSEM time-domain response of CO2 injected into a saline reservoir following the multi-transient electromagnetic (MTEM) method. The MTEM method measures the full bandwidth response. First, I model the response to a simple homogeneous 3D CO2 body, gradually increasing the width and depth of the CO2. This is an analogue to vertical and lateral CO2 migration in a reservoir. I then assess the ability of CSEM to detect CO2 plume growth and evolution within the heterogeneous Bunter Sandstone reservoir model. I demonstrate the potential to detect stored and migrating CO2 and present the synthetic results as time-lapse common-offset time sections. The CO2 plume is imaged clearly and in the right coordinates. The ability to image seismically a migrating front of CO2 remains challenging due to uncertainties regarding the pore-scale saturation distribution of fluids within the reservoir and, in turn, the most appropriate rock-physics model to simulate this: uniform or patchy saturation. I account for this by modelling both saturation models, to calculate the possible range of expected seismic velocities prior to generating and interpreting the seismic response. I demonstrate the ability of seismic methods to image CO2 plume growth and evolution in the Bunter Sandstone saline reservoir model and highlight clear differences between the two rock-physics models. I then modify the Bunter Sandstone reservoir to depict a depleted gas field by including 20% residual gas saturation. I assess the importance and implication of patchy saturation and present results which suggest that seismic techniques may be able to detect CO2 injected into depleted hydrocarbon fields.

Le emissioni di CO2 provocate dallo sfruttamento dei combustibili fossili da parte dell'uomo ha portato ad una concentrazione di questo gas serra in atmosfera tale da dover essere monitorata, se non diminuita. E' d'obbligo sfruttare le fonti energetiche in modo più sostenibile: oltre a ridurre il più possibile le emissioni di CO2 è necessario sfruttare appieno le fonti rinnovabili. Soluzione comune a questi due aspetti è il concetto di Power to Gas, o Power to Methane, il cuore del quale è la reazione di metanazione: catturando la CO2 altrimenti dispersa in atmosfera e facendola reagire in appositi catalizzatori con idrogeno ottenuto tramite idrolisi dell'acqua, utilizzando elettricità derivante da fonti rinnovabili, si ottiene metano. In questo modo si può sopperire alla fornitura di energia senza dipendere dai combustibili fossili e con emissioni nulle. In questa tesi si approfondiranno gli aspetti generali della metanazione, soprattutto sulla termodinamica, e si mostrerà quanto sia importante che il concetto di PtM si possa applicare il più possibile su vasta scala.

The interoperability of the electronic documents exchanged in eBusiness applications is an important problem in industry. Currently, this problem is handled by the mapping experts who understand the meaning of every element in the involved document schemas and define the mappings among them which is a very costly and tedious process. In order to improve electronic document interoperability, the UN/CEFACT produced the Core Components Technical Specification (CCTS) which defines a common structure and semantic properties for document artifacts. However, at present, this document content information is available only through text-based search mechanisms and tools. In this thesis, the semantics of CCTS based business document standards is explicated through a formal, machine processable language as an ontology. In this way, it becomes possible to compute a harmonized ontology, which gives the similarities among document schema ontology classes of different document standards through both the semantic properties they share and the semantic equivalences established through reasoning. However, as expected, the harmonized ontology only helps discovering the similarities of structurally and semantically equivalent elements. In order to handle the structurally different but semantically similar document artifacts, heuristic rules are developed describing the possible ways of organizing simple document artifacts into compound artifacts as defined in the CCTS methodology. Finally, the equivalences discovered among document schema ontologies are used for the semi-automated generation of XSLT definitions for the translation of real-life document instances.

Charge Coupled Devices (CCDs) are low power, robust detectors promising medium spectral resolution, high spatial resolution and a high signal to noise ratio. It is for this reason that CCDs have become the preferred focal plane detector in all x-ray astronomy missions due for launch in the 1990s and early in the next millennium. The absorption of x-rays by a CCD is modulated by the transmission of the complex electrode structures and passivation layers on its front surface. Since the path length of soft x-rays (0.l1 - 2 keV) is of the same order as the thickness of these layers, fine structure in the quantum efficiency (Q(E)) around absorption edges can have a profound influence on the response of the CCD. This thesis presents the work done in investigating fine structure effects in the Q(E) of x-ray CCDs and the impact that these effects will have on astronomy missions. The state of x-ray astronomy as we move into the CCD-mission era is reviewed in Chapter 2. the operation of a CCD as an x-ray detector is then described. The extensive set of experiments carried out at the Daresbury Synchrontron Radiation Source (SRS) to map the Q(E) of JET-X CCDs are detailed, including a description of the first use of the new, low beam current mode of SRS operation. Chapter 5 describes the origins and expression of X-ray Absorption Fine Structure (XAFS) in the CCD response. The instruments that make up the JET-X Focal Plane Cameras are then reviewed. In Chapter 7 the importance of calibrating JET-X accurately is shown by analysing the impact of XAFS in the detector sub-systems. It is shown that XAFS threaten the scientific return from current and future x-ray astronomy missions. In Chapter 8 the information contained by the fine structure in the CCD Q(E) is extracted and analysed to obtain the thickness and structure of the inert layers on the surface of the CCD, and also to improve models of the CCD response. Finally the work is summarised and additional further work is suggested.

Join us as we discuss ideas to integrate math, reading, and science (e.g. force and motion, weather) into K–5 classrooms to build confidence about using reading and math as tools to understand STEM literacies.

Il principale responsabile del riscaldamento globale è l’anidride carbonica che costituisce circa 76% dei gas ad effetto serra rilasciati in atmosfera. Il problema ha sollevato sempre più preoccupazioni, finché nel 1997 in occasione della Conferenza delle parti COP3 venne sottoscritto il Protocollo di Kyoto. Allo scadere del 2012, a Parigi si tenne un'altra conferenza sul clima in cui venne sottoscritto l'Accordo di Parigi. Gli obiettivi dell’Accordo di Parigi impongono un mantenimento dell’aumento medio di temperatura entro 2°C rispetto al livello di temperatura relativo ai valori preindustriali. Raggiungere gli obiettivi fissati dall’Accordo di Parigi, allo stato attuale è difficile a meno di sequestrare l’anidride carbonica dall’atmosfera. Pertanto contestualmente si ricerca la possibilità di catturare l’anidride carbonica rilasciata nell’atmosfera da grandi impianti di combustione in modo da limitare almeno in parte il suo continuo incremento, a tal fine sono state pensate le diverse tecniche di cattura e stoccaggio dell’anidride carbonica nel sottosuolo, (carbon capture and storage, CCS). Il mancato successo della cattura e sequestro dell’anidride carbonica sembra essere legato non solo a fattori economici ma anche alla sicurezza di trasporto della sostanza una volta catturata e alle condizioni geologiche del sito di sequestro finale. Dato un notevole dispendio economico nell’applicazione delle tecniche di cattura dell’anidride carbonica la via preferenziale è quella di riutilizzarla nel recupero assistito del greggio (EOR). Inoltre per trovare delle alternative sostenibili si valutano le applicazioni delle tecniche CCS come il riutilizzo della CO2 e le bioenergie. Ma i costielevati e le mancanze di iniziative politiche a livello nazionale mettono l'applicazione delle CCS a dura prova.

In order to meet the IMO’s (International Maritime Organisation) target of 14% reduction of CO₂ emissions from marine activities by 2020, the application of Carbon Capture and Storage (CCS) on ships is considered as an effective way to mitigate the CO₂ emission while other low carbon shipping emission technologies are being developed. A comprehensive literature review of onshore CCS applications has indicated that current CCS technologies could not be implemented on-board directly due to the various limitations of ships, such as constraint space and system retrofit. In this thesis, a novel method of chemical CO₂ absorption and solidification for marine applications is analysed and presented. Technical feasibility and cost assessment of this method are carried out by comparison with the conventional method (liquefaction) for a case study ship. The thesis will also present results obtained from laboratory-scale experiments. Theoretical study and lab-scale experiments have shown that the proposed CO₂ absorption and solidification method is a promising, cost-effective and practicable method for CO₂ emissions reduction on ships. Carbon capture and storage is an excellent solution for reducing the greenhouse gas emissions from applications on shore. A novel method to absorb and solidify CO₂ from the exhaust gases on the ship is proposed and verified. CO₂ gas flow rate, the geometry of the absorption tanks and the concentration of the absorption solution are key factors that affect the reaction efficiency. The experimental results illustrate the impacts of these factors on CO₂ absorption efficiency. Meanwhile, the effects of these key factors on CO₂ absorption rates will also be presented in the CFD simulations of this thesis. Pressure distributions, the concentration of the solution and the velocity of both the gas and the solution during the different processes will be derived from the numerical simulations. The results of the simulations provide fundamental details for the design of a prototype demonstration system on-board a ship. In addition to the key factors discussed above, the effect of atmospheric temperature will be observed and analysed. With a comparison of experimental data and CFD simulation results, it will be demonstrated that the CFD simulations of the effects of CO₂ gas flow rate, the geometry of the absorption container and the concentration of the absorption solution on absorption rate have a good agreement with the experimental results. Optimised values of these factors are obtained from the comparisons and analyses. The numerical simulations will [sic] carried out to test the impact of phase temperature on absorption rate also indicate the optimal temperature for carrying out the absorption process. As the simulation results match with the experimental results, the simulation model developed is considered to be applicable for a case study ship practical system simulation. Geometry, fluid flow rate, temperature and some other parameters are adjusted to fit a practical system. At this stage, the practical system is designed and the most appropriate absorption process is selected. The designated system is modelled and simulated based on the simulation processes from the lab-scale experiments. The orthogonal design method is applied to optimise the system. Key parameters are varied within a reasonable range so that a large number of trials are initially needed to find the optimal one. With the orthogonal design method, the number of trials is reduced so that computing intensity is reduced and finally the optimised absorption system is derived. The volume required for the precipitation tanks, CaO and CaCO₃ storage tanks and the centrifuge separation are derived and the installation and positioning of these tanks, as well as the positioning of the whole system, will be presented. It is concluded that CCS for marine activities could enable ships to comply with various regional and international CO₂ emissions regulation whilst also maintaining the efficiency of waterborne transportation. The whole design process for the case study ship is presented here and could be applied as a guideline process for new design, analysis and installation.

Denna studie syftar till att undersöka berörda samhällsaktörers inställning till att uppnå klimatneutralitet inom Sverige med bio-CCS som åtgärd. En kvalitativ innehållsanalys av remisser från klimatpolitiska vägvalsutredningens betänkande Vägen till en klimatpositiv framtid genomfördes med ett multi-level perspective för att studera dessa aktörers ståndpunkt. Aktörernas synpunkter identifieras och analyseras för att därefter ställas mot tidigare forskning. Resultatet av studien visar att det finns delade uppfattningar hos aktörerna angående bio-CCS och vad som behövs för att främja tekniken. De största hindren till att implementera bio-CCS som åtgärd anses vara ekonomiska och politiska aspekter, men att det även finns andra faktorer som har en betydande roll för att bio-CCS ska kunna ha ett inflytande till att Sverige ska uppnå klimatneutralitet till 2045.
This study aims to investigate the approach of relevant actors to achieving climate neutrality within Sweden with bio-CCS as a measure. A qualitative content analysis of referrals from the climate policy inquiry report Vägen till en klimatpositiv framtid carried out with a multi-level perspective theory to study the position of these actors. The actors' views are identified and analyzed and compared to previous research. The results show that there are divided opinions among actors regarding bio-CCS and what is needed to promote the technology. The main obstacles to implementing bio-CCS as a measure are considered to be economic and political aspects, other factors also have a significant role in influencing Sweden to achieve climate neutrality by 2045.

The present work is related to the complete analysis of biogas-fed SOFC system. The first part of the work has been related to a review on the concept of polygeneration system and on the analysis of the current status of SOFC installations, especially when fed with biogas. The use of a renewable fuel, coupled with carbon capture, can lead to negative emissions plants, defined as key technologies for reaching the goals set in the Paris Agreement. Furthermore, biogas and SOFC show many affinities which have been discussed in the works: from the high efficiency at low sizes to the availability of already existing subsidy schemes for electricity production. An analysis of the potential biogas production in EU is proposed, with focus on wastewater treatment plants. In this particular area, the work tries to point out the numbers of potential installed power by using SOFCs. The experimental and modeling activities are then proposed. The PhD activity is linked to two European projects, SOFCOM and DEMOSOFC. The first project is related to the analysis of biogas fed SOFC system with carbon capture and re-use. In this context, a demonstration plant has been developed and tested in the SMAT Castiglione wastewater treatment plant. Results show an easy process for the CO2 capture from the SOFC exhaust, thus pointing SOFC as a key technology in the framework of negative carbon emissions plants. More criticalities have been found in the choice of CO2 utilization for production of algae in a photobioreactor: the unstable quality of the inlet wastewater coming from the plant, the fluctuating algae productivity as function of the weather conditions, and the algae attachment to the pipe, pointed out a need for improvements and research on this technology. The experimental activity has been coupled with a modeling activity on the same concept of biogas fed SOFC, with the possibility of a downstream carbon capture and use/ sequestration. Different plant layout and different system sizes have been analyzed from a technical and economical point of view. Finally, the analysis of a real industrial size SOFC system is proposed. This activity has been developed in the framework of the DEMOSOFC EU project, where the first industrial size biogas fed SOFC system will be installed. Being the first installation of its kind, many issued and improvements have been detected. The analysis is related to the system design and description, for what concerning plant integration (electrical and thermal), system operation, and biogas processing. Biogas processing has been especially pointed out as a key component in a biogas-fed SOFC system. Because of the low admissible contaminants levels for fuel cell, a new and dedicated cleaning unit is required, which is not currently available on the market. The processing unit design is proposed and ongoing experimental activity on the adsorption with activated carbons are proposed. The main harmful contaminants found in wastewater biogas are sulphur (in the form of H2S) and siloxanes (mainly D4 and D5).

Un code de simulation de plasma à deux dimensions électrostatique à coordonnées cartésiennes Particle-in-cell/ Monte Carlo Collision (PIC/MCC) est présenté, incluant un nouveau traitement de l'équilibre des charges aux limites diélectriques. Il est utilisé pour simuler un plasma dans le gaz Ar dans un réacteur à plaques parallèles à couplage capacitif à radiofréquence a géométrie symétrique avec une paroi latérale diélectrique épaisse. La paroi latérale diélectrique protège efficacement le plasma du champ électrique augmenté au niveau de la jonction entre l'électrode alimentée et l'électrode à la masse, dont on a montré précédemment qu'elle produisait une augmentation localise de la densité de plasma. Néanmoins, un réchauffement accru des électrons est observé dans une région adjacente à la limite diélectrique, conduisant à des maxima de le taux d'ionisation, de la densité du plasma et du flux ionique vers les électrodes dans cette région. Les différents composants du chauffage électronique sont dérivés des simulations PIC/MCC et montrent que cette augmentation du chauffage électronique provient d'un chauffage ohmique accru dans la direction axiale lorsque la densité électronique diminue vers la paroi latérale. Nous avons étudié la validité de différentes formules analytiques pour estimer le chauffage ohmique en les comparant aux résultats PIC. Le chauffage des électrons à composantes x a proximité des coins a été observé aux fréquences d'excitation plus élevées, provenant d'un champ RF oscillant important dans la direction x
A Cartesian-coordinate two-dimensional electrostatic Particle-in-cell/Monte-Carlo Collision (PIC/MCC) plasma simulation code is presented, including a new treatment of charge balance at dielectric boundaries. It is used to simulate an Ar plasma in a symmetric radiofrequency capacitively-coupled parallel-plate reactor with a thick dielectric side-wall. The dielectric side-wall effectively shields the plasma from the enhanced electric field at the powered-grounded electrode junction, which has previously been shown to produce locally enhanced plasma density. Nevertheless, enhanced electron heating is observed in a region adjacent to the dielectric boundary, leading to maxima in ionization rate, plasma density and ion flux to the electrodes in this region. The electron heating components are derived from the PIC/MCC simulations and show that this enhanced electron heating results from increased Ohmic heating in the axial direction as the electron density decreases towards the side-wall. We investigated the validity of different analytical formulas to estimate the Ohmic heating by comparing them to the PIC results. The x component electron heating near the corners was observed at higher driving frequency, which is caused by a significant RF oscillating field in the x direction

De nombreuses observations astrophysiques et cosmologiques tendent à favoriser le fait que 80% de la matière de l’Univers est constitué d’une matière inconnue et interagissant peu avec la matière ordinaire, la matière sombre. Cependant sa nature reste une des inconnues de la physique moderne. Actuellement la vaste majorité des expériences de détection directe de matière sombre n’ont encore rien détecté. L’expérience Dark Matter In CCDs (DAMIC) à SNOLAB est l’une d’entre elles et utilise des Charged Coupled Devices (CCDs, semi-conducteurs en silicium, comme détecteur. Mon travail au sein de la collaboration DAMIC a été centré sur la production d’un modèle de bruit de fond radioactif à l’aide de l’outil GEANT4. On commencera par introduire l’expérience DAMIC à SNOLAB pour présenter la simulation de l’expérience, de la génération des isotopes radioactifs à la simulation de la réponse du détecteur aux dépôts d’énergies des particules simulées. J’exposerai ensuite les origines et caractéristiques des différents isotopes présents dans l’expérience, informations que l’on a obtenues grâce à des mesures dites de screening, des publications et analyses. Pour terminer je présenterais le modèle de bruit de fond radioactif issu de l’ajustement des simulations au données et la sensibilité de l’expérience DAMIC
A large number of astrophysical and cosmogical observations promote the fact that 80\% of the matter in the Universe is made of an unknown dark matter weakly interacting with the ordinary matter, the dark matter. However little is known about it, and its nature remains one of the unknown of modern physics. Nowadays the vast majority of the direct detection dark matter experiments didn’t detect anything. The Dark Matter In CCDs (DAMIC) experiment at SNOLAB is one of them, and uses Charged Coupled Devices, silicon semi-conductors, as detectors. My work within the DAMIC collaboration was mainly focused on the construction of the radioactive background model with the GEANT4 toolkit. To start we will introduce the DAMIC at SNOLAB experiment and present the simulation of the experiment, from the generation of primary particle to the simulation of the detector behavior to the energy deposit of the particles simulated. Then I will show you the origins and characteristics of the different radioactive isotopes present in the experiment, information that we retrieved from papers, screening measurement and analysis. To finish I will present the radioactive background model coming from the fit of the simulations to the data and the sensibility of the DAMIC experiment