Techno-Economic Feasibility of Selective CO2 Capture Processes from Biogas Streams using Ionic Liquids as Physical Absorbents

Biogas from anaerobic digestion of sewage sludge is a renewable resource with high energy content, which is formed mainly of CH4 (40-75 vol.%) and CO2 (15-60 vol.%) Other components such as water (H2O, 5-10 vol.%) and trace amounts of hydrogen sulfide and siloxanes can also be present. A CH4-rich stream can be produced by removing the CO2 and other impurities so that the upgraded bio-methane can be injected into the natural gas grid or used as a vehicle fuel. The main objective of this paper is to develop a new modeling methodology to assess the technical and economic performance of biogas upgrading processes using ionic liquids which physically absorb CO2. Three different ionic liquids, namely the 1-ethyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide, 1-hexyl-3-methylimidazoliumbis[(trifluoromethyl)sulfonyl]imide and trihexyl(tetradecyl)phosphonium bis[(trifluoromethyl)sulfonyl]imide, are considered for CO2 capture in a pressure-swing regenerative absorption process. The simulation software Aspen Plus and Aspen Process Economic Analyzer is used to account for mass and energy balances as well as equipment cost. In all cases, the biogas upgrading plant consists of a multistage compressor for biogas compression, a packed absorption column for CO2 absorption, a flash evaporator for solvent regeneration, a centrifugal pump for solvent recirculation, a pre-absorber solvent cooler and a gas turbine for electricity recovery. The evaluated processes are compared in terms of energy efficiency, capital investment and bio-methane production costs. The overall plant efficiency ranges from 71-86 % whereas the bio-methane production cost ranges from £6.26-7.76 per GJ (LHV). A sensitivity analysis is also performed to determine how several technical and economic parameters affect the bio-methane production costs. The results of this study show that the simulation methodology developed can predict plant efficiencies and production costs of large scale CO2 capture processes using ionic liquids without having to rely on gas solubility experimental data.

Environnements didactiques informatiques et pédagogie du projet analyse de l'intervention éducative d'un enseignant en milieu scolaire socioéconomiquement faible

Cette étude de cas analyse l'intervention éducative d'un enseignant du primaire qui a mis en oeuvre un dispositif didactique et pédagogique intégrant de façon systématique l'informatique scolaire à une pédagogie du projet dans le but de mieux répondre aux besoins liés à l'apprentissage d'élèves provenant d'un milieu socioéconomiquement faible.Cette étude longitudinale (1998-2001) fait ressortir l'impact de l'agir professionnel sur la réussite scolaire. La problématique de notre recherche s'inscrit dans la foulée de la réforme en cours, dont l'une des visées est de contrer le retard scolaire au primaire et le risque d'échec et d'abandon scolaire précoce au secondaire. Quatre dimensions éclairent l'implémentation du dispositif: l'équité sociale, les changements épistémologiques, une orientation vers la socialisation et le rôle des TIC pour soutenir le développement des compétences transversales. Le cadre conceptuel s'appuie sur une perspective socioconstructiviste cohérente avec la théorie de l'anthropologie culturelle de Vygotsky (1978) pour qui l'apprentissage ne se fait pas seul, mais avec l'aide de pairs plus avancés en contexte de cognition située. La médiation de l'enseignant, par sa réflexion en action , en synchronie avec les besoins immédiats de ses élèves, établit le lien entre enseignant et apprenants, pour qu'ils puissent développer un esprit d'initiative, ainsi que la responsabilité et l'autonomie pour assumer leurs apprentissages. Une méthodologie mixte interreliant des méthodes qualitatives et quantitatives a exigé un recueil de données sur des dimensions descriptives et évaluatives. Des données de deuxième ordre, issues d'une recherche FCAR (98-NT-004), ont permis de dégager des caractéristiques spécifiques à la planification, à la gestion de classe et aux comportements de l'"enseignant-cible" en contexte de pédagogie du projet. Les résultats obtenus par les 23 élèves aux examens sommatifs de 6e année témoignent de l'efficacité de l'intervention. La présente étude pourrait avoir des retombées en tant que modèle pour d'autres chercheurs intéressés à étudier l'impact des TIC comme matériel didactique. Sur le plan de la pratique, ce type d'intervention serait un moyen efficace pour contrer le décrochage scolaire chez les élèves en mobilisant leurs capacités de s'adapter avec succès à leur environnement, malgré les facteurs de risque qui pourraient les inhiber.

Petites obsessions ironie et satire dans l'écriture de nouvelles destinées à la jeunesse

Petites obsessions : ironie et satire dans l'écriture de nouvelles destinées à la jeunesse", mémoire en création littéraire, comporte deux parties. La première présente un recueil de nouvelles humoristiques destinées à un lectorat jeunesse. Ces nouvelles, au nombre de huit, bien que différentes les unes des autres, partagent une même thématique, l'obsession, et des tonalités humoristiques comparables, soit la satire et l'ironie. La seconde partie de ce mémoire, plus théorique, se divise en trois sections. D'abord, on trouve une section traitant de la littérature jeunesse; on y parle du héros et du système de personnages, de l'humour utilisé dans ce type de littérature et, finalement de quelques thèmes fréquemment rencontrés : amour, intégration au groupe de pairs, identité, liberté et indépendance, nouvelles réalités sociales. Ce portrait rapide et succinct de la littérature jeunesse vient étayer les stratégies d'écriture utilisées lors de la rédaction de Petites obsessions , stratégies susceptibles de favoriser l'éclosion de l'humour dans un contexte littéraire. L'analyse d'un corpus restreint, mais représentatif, qui s'ensuit (Raymond Plante, Robert Soulières, Sylvie Desrosiers et Denis Côté) permet d'observer concrètement la présence des divers éléments textuels décrits en première partie, pour ensuite les mettre en corrélation avec la création littéraire proprement dite. À cette dernière étape, consignée dans la troisième section, s'ajoute une réflexion sur l'intentionnalité qui fonde l'écriture de Petites obsessions de même que sur les cibles qui y sont visées.

Die Fledermaus, November 18, 19, 21, and 22, 1977

Concert program for Die Fledermaus, November 18, 19, 21, and 22, 1977

The Guitar Ensemble May 11, 2002

Concert Program for The Guitar Ensemble May 11, 2002

Guitar Ensemble May 24, 2001

Concert Program for Guitar Ensemble May 24, 2001

Guitar Ensemble February 15, 2001

Concert Program for Guitar Ensemble February 15 2001

The Guitar Ensemble May 24, 2003

Concert Program for The Guitar Ensemble May 24 2003

The Guitar Ensemble February 8, 2003

Concert Program for The Guitar Ensemble February 8, 2003

Telling stories of culture through literature

Grounded on Raymond Williams‘s definition of knowable community as a cultural tool to analyse literary texts, the essay reads the texts D.H.Lawrence wrote while travelling in the Mediterranean (Twilight in Italy, Sea and Sardinia and Etruscan Places) as knowable communities, bringing to the discussion the wide importance of literature not only as an object for aesthetic or textual readings, but also as a signifying practice which tells stories of culture. Departing from some considerations regarding the historical development of the relationship between literature and culture, the essay analyses the ways D. H. Lawrence constructed maps of meaning, where the readers, in a dynamic relation with the texts, apprehend experiences, structures and feelings; putting into perspective Williams‘s theory of culture as a whole way of life, it also analyses the ways the author communicates and organizes these experiences, creating a space of communication and operating at different levels of reality: on the one hand, the reality of the whole way of Italian life, and, on the other hand, the reality of the reader who aspires to make sense and to create an interpretative context where all the information is put, and, also, the reality of the writer in the poetic act of writing. To read these travel writings as knowable communities is to understand them as a form that invents a community with no other existence but that of the literary text. The cultural construction we find in these texts is the result of the selection, and interpretation done by D.H.Lawrence, as well as the product of the author‘s enunciative positions, and of his epistemological and ontological filigrees of existence, structured by the conditions of possibility. In the rearticulation of the text, of the writer and of the reader, in a dynamic and shared process of discursive alliances, we understand that Lawrence tells stories of the Mediterranean through his literary art.

O regresso da homogeneidade no post Guerra Fria. Uma inversão da tendência histórica de progressiva heterogeneidade na natureza do sistema internacional?

Dissertação apresentada para cumprimento dos requisitos necessários à obtenção do grau de Mestre em Ciência Política e Relações Internacionais (especialização em Relações Internacionais)

Safety and occlusion rates of surgical treatment of unruptured intracranial aneurysms: a systematic review and meta-analysis of the literature from 1990 to 2011.

BACKGROUND AND PURPOSE: Surgical clipping of unruptured intracranial aneurysms (UIAs) has recently been challenged by the emergence of endovascular treatment. We performed an updated systematic review and meta-analysis on the surgical treatment of UIAs, in an attempt to determine the aneurysm occlusion rates and safety of surgery in the modern era. METHODS: A detailed protocol was developed prior to conducting the review according to the Cochrane Collaboration guidelines. Electronic databases spanning January 1990-April 2011 were searched, complemented by hand searching. Heterogeneity was assessed using I(2), and publication bias with funnel plots. Surgical mortality and morbidity were analysed with weighted random effect models. RESULTS: 60 studies with 9845 patients harbouring 10 845 aneurysms were included. Mortality occurred in 157 patients (1.7%; 99% CI 0.9% to 3.0%; I(2)=82%). Unfavourable outcomes, including death, occurred in 692 patients (6.7%; 99% CI 4.9% to 9.0%; I(2)=85%). Morbidity rates were significantly greater in higher quality studies, and with large or posterior circulation aneurysms. Reported morbidity rates decreased over time. Studies were generally of poor quality; funnel plots showed heterogeneous results and publication bias, and data on aneurysm occlusion rates were scant. CONCLUSIONS: In studies published between 1990 and 2011, clipping of UIAs was associated with 1.7% mortality and 6.7% overall morbidity. The reputed durability of clipping has not been rigorously documented. Due to the quality of the included studies, the available literature cannot properly guide clinical decisions.

Clinical presentation, etiology, and outcome of infective endocarditis in the 21st century: the International Collaboration on Endocarditis-Prospective Cohort Study.

We sought to provide a contemporary picture of the presentation, etiology, and outcome of infective endocarditis (IE) in a large patient cohort from multiple locations worldwide. Prospective cohort study of 2781 adults with definite IE who were admitted to 58 hospitals in 25 countries from June 1, 2000, through September 1, 2005. The median age of the cohort was 57.9 (interquartile range, 43.2-71.8) years, and 72.1% had native valve IE. Most patients (77.0%) presented early in the disease (<30 days) with few of the classic clinical hallmarks of IE. Recent health care exposure was found in one-quarter of patients. Staphylococcus aureus was the most common pathogen (31.2%). The mitral (41.1%) and aortic (37.6%) valves were infected most commonly. The following complications were common: stroke (16.9%), embolization other than stroke (22.6%), heart failure (32.3%), and intracardiac abscess (14.4%). Surgical therapy was common (48.2%), and in-hospital mortality remained high (17.7%). Prosthetic valve involvement (odds ratio, 1.47; 95% confidence interval, 1.13-1.90), increasing age (1.30; 1.17-1.46 per 10-year interval), pulmonary edema (1.79; 1.39-2.30), S aureus infection (1.54; 1.14-2.08), coagulase-negative staphylococcal infection (1.50; 1.07-2.10), mitral valve vegetation (1.34; 1.06-1.68), and paravalvular complications (2.25; 1.64-3.09) were associated with an increased risk of in-hospital death, whereas viridans streptococcal infection (0.52; 0.33-0.81) and surgery (0.61; 0.44-0.83) were associated with a decreased risk. In the early 21st century, IE is more often an acute disease, characterized by a high rate of S aureus infection. Mortality remains relatively high.

Infancy Gospels. Stories and Identities

Even though the canonical Jesus' infancy stories have always provoked great interest in popular culture and in the arts, they have been neglected in research during the last decades due to the relatively late date of their redaction. Since the monograph by Raymond Brown, The Birth of the Messiah , the researchers working on this topic have not attempted to consider its historical impact. In this volume, an international team of scholars proposes firstly a reconsideration of the historical background of these stories in terms of early Jewish and Christian identity quests. Secondly, they deal with early Christian questions on Jesus' infancy and childhood through canonical and apocryphal Gospels including information from Patristic and documentary literature. On the theological level, this volume illustrates the impact that these apocryphal texts, recognized as "useful for the soul" (a phrase coined by François Bovon), have had on the Christian faith.

Subgroup-specific structural variation across 1,000 medulloblastoma genomes.

Medulloblastoma, the most common malignant paediatric brain tumour, is currently treated with nonspecific cytotoxic therapies including surgery, whole-brain radiation, and aggressive chemotherapy. As medulloblastoma exhibits marked intertumoural heterogeneity, with at least four distinct molecular variants, previous attempts to identify targets for therapy have been underpowered because of small samples sizes. Here we report somatic copy number aberrations (SCNAs) in 1,087 unique medulloblastomas. SCNAs are common in medulloblastoma, and are predominantly subgroup-enriched. The most common region of focal copy number gain is a tandem duplication of SNCAIP, a gene associated with Parkinson's disease, which is exquisitely restricted to Group 4α. Recurrent translocations of PVT1, including PVT1-MYC and PVT1-NDRG1, that arise through chromothripsis are restricted to Group 3. Numerous targetable SCNAs, including recurrent events targeting TGF-β signalling in Group 3, and NF-κB signalling in Group 4, suggest future avenues for rational, targeted therapy.