Development and application of a laminar coflow burner for combustion studies at high pressure

In the present thesis, it is attempted to build a bridge between the most simplified systems that have already been studied in literature (laminar flame burners, in which simple fuels such as methane, ethane or ethylene are burnt at atmospheric pressure) and the much more complex and demanding environment that is found in practical combustion engines. This is accomplished by designing and constructing a high pressure vessel and laminar burner (HPVB) integrated with an evaporation system. The capability of the HPVB setup of burning vaporized liquid fuels in laminar diffusion and partially premixed flames brings the important opportunity to isolate more easily the impact of fuel chemistry on the combustion behavior of relevant fuels and biofuels. This experimental setup is particularly designed to offer optical accessibility for laser diagnostic techniques, also allowing their assessment and development at elevated pressures. Background information on the type of burners mostly used for combustion studies in laminar flames is given in chapter 2 with focus on measurements in a high pressure environment. A detailed description of the design capabilities of the HPVB setup and the flame stability issues encountered are also presented and discussed. The theory behind the laser diagnostic techniques applied in this work are reviewed in chapter 3. The chapters 4 to 6 present the measurements carried out to characterize a large range of flames from gaseous and vaporized liquid fuels using laser diagnostics. In chapter 7, the heat flux method for laminar burning velocity measurements is presented and a feasibility study is performed to extend the applicability of the method to higher pressures. This is accomplished by integrating the heat flux burner in the high pressure vessel of the HPVB setup. Chapter 8 summarizes the conclusions and provide recommendations

Second-Order Finite Automata

Traditionally, finite automata theory has been used as a framework for the representation of possibly infinite sets of strings. In this work, we introduce the notion of second-order finite automata, a formalism that combines finite automata with ordered decision diagrams, with the aim of representing possibly infinite sets of sets of strings. Our main result states that second-order finite automata can be canonized with respect to the second-order languages they represent. Using this canonization result, we show that sets of sets of strings represented by second-order finite automata are closed under the usual Boolean operations, such as union, intersection, difference and even under a suitable notion of complementation. Additionally, emptiness of intersection and inclusion are decidable. We provide two algorithmic applications for second-order automata. First, we show that several width/size minimization problems for deterministic and nondeterministic ODDs are solvable in fixed-parameter tractable time when parameterized by the width of the input ODD. In particular, our results imply FPT algorithms for corresponding width/size minimization problems for ordered binary decision diagrams (OBDDs) with a fixed variable ordering. Previously, only algorithms that take exponential time in the size of the input OBDD were known for width minimization, even for OBDDs of constant width. Second, we show that for each k and w one can count the number of distinct functions computable by ODDs of width at most w and length k in time h(|Σ|,w) ⋅ kO(1), for a suitable $h:\mathbb {N}\times \mathbb {N}\rightarrow \mathbb {N}$. This improves exponentially on the time necessary to explicitly enumerate all such functions, which is exponential in both the width parameter w and in the length k of the ODDs.publishedVersio

Sociologie sémantico-logique des ruines : pour une herméneutique hybride de la ruine du Web 2.0 au Web 3.0

Le terme ruine renvoie, à la fois, à un processus social complexe et à un concept polysémique. Les ruines constituent également un phénomène qui a une nature relationnelle. Par conséquent, une étude sociologique possible se constitue à partir des deux piliers suivants : (a) des concepts interprétés en utilisant une posture sémantique à l’égard du social et du sociologique ; (b) des relations sociales de nature logique et hybride. Ce texte développe ce type de réflexion en utilisant les outils théoriques et méthodologiques construits au sein d’un paradigme sociologique nommé Sociologie sémantico-logique et à l’intérieur de l’une de ses tactiques, l’Hybridologie sociale, qui utilise en particulier un style d’interprétation désigné Herméneutique hybride. Cette méthodologie est appliquée à l’analyse de contenu et de discours de la page « Ruins » de Wikipédia, en essayant d’y extraire les sens polymorphes qui traduisent l’imaginaire subjacent à la forme sociale «ruine»

Sociological ontology of the digital public sphere : the case of Web 2.0/3.0

Digital public sphere is immersed in the present conjuncture of accelerated transformation and probable rupture, which certainly will affect the way we exercise our citizenship in contemporary times. This social and political tsunami is partly based on the change of paradigm of Web 2.0 or Social Web to Web 3.0 or Semantic Web. To clarify such a process, this paper discusses some of the key issues and theoretical positions on public space, from seminal Habermas’s perspective to new problematics raised by the networked society. The author suggests the construction of a Sociological Ontology of Social and Semantic Web, based on a Semantic-Logical Sociology and Methodology. These procedures are applied through the analysis and hermeneutics of a Wikipedia page entitled ‘Web 2.0’, where sociological experimental tools are used, as Semantic-Logical fields, trees and networks, central and peripheral concepts, and trichotomies

Innovative game genres: sociological games

In the last decades, the game scene has changed irreversibly: thousands of new game titles are been produced every year. Game industry is on the top of growth rate among cultural industries. However, and strangely enough, game genres and styles suffer from a lack of innovation and changed in a very lower rythm along the very history of digital games. An interesting critique on the nature of games and about the necessity of changing our game design rules and sensibility was done by Mary Flanagan (2009). My own reserach considers this experimental and social posture. E.g. we constructed a new breed of the so-called ‘serious’ and ‘educational’ games, aiming to allow not just the learning, but the practice of Sociology, that can be called Sociological Games. In other words, Sociological Games can be defined as games that reflect deeply on the very nature of social life, while playing with it. The following examples present some possibilities and prototypes in this direction

Open research for diffusion of open digital memories at Web 2.0/3.0

This paper suggests an experimental perspective of Open Research, understood as a process of deconstruction of knowledge about society that leads to its reconstruction, archiving and dissemination in the form of Open Digital Memories. This posture was developed within the Project Public Communication of Art: the Case of Global / Local Art Museums, at the University of Lisbon. The project was funded by Foundation for Science and Technology, and produced 6 books and 8 sites, among other final results. Researching and memorizing may be pursuited through an open style that includes the production and reception of investigation by both the researcher and the common citizen. This may involve multiple shared tasks: questioning the social, organization and critique of sources and data, co-participation in the use of methods, public discussions on work in progress and on research results. For this aim, Open Research must articulate Social Sciences and Humanities to New Media, specially across digital social networks, both at Web 2.0 (the Reading/Writing Internet) and at Web 3.0 (the so-called Semantic Web). Two strategies contributing to this posture will be exemplified, within the optics of Semantic-Logic Sociology: Experimental Books and Social Semantic-Logic Sites. They use the following instruments for producing/writing and receiving/reading social and semantic knowledge, some of these shown in the present paper: Visual Ontologies built from Social Hybridologies, GeoNeoLogic Methods (Multitouch Questionnaire, Trichotomies Game, etc..), Conceptual Abstracts, Present Books, Author-Actor Maps, GeoNeoLogic Novels, Visual Social Ontologies, Knowledge Interactive Windows, Visual Socio-Semantic Indexes, Visual Meta-Semantic Indexes. In short, Open Research and Open Digital Memories may constitute some of the fundamental pillars of emergent Research Society. This means a social paradigm where common citizens may become a sort of ‘lay researchers’ and, in the process, reformulate contemporary expert’s knowledge and power.Fundação para a Ciência e a Tecnologia (FCT

A cidade interdimensional e as práticas públicas quotidianas

O presente texto visa relacionar uma visão interdimensional da urbe com algumas das suas práticas quotidianas concretas, como o beber em público. De facto, as ações diárias dos atores sociais, se bem que se encontrem parcialmente determinadas pelas estruturas e instituições sociais que subjazem a uma situação social, igualmente condicionam, menos ou mais intensamente, essas instâncias abstratas do social. E um tal processo passa-se, em grande parte, através da mediação do espaço público urbano, onde o público e o privado se encontram e defrontam. Para tal, uma reflexão teórica preliminar articula as paisagens sociais interdimensionais à história da cidade. Em seguida, as dimensões sociais da vizinhança são consideradas e interpretadas nas diversas dimensões societais. Finalmente, fornece-se uma ilustração de uma prática de vizinhança concreta, o beber público na urbe.info:eu-repo/semantics/publishedVersio

Mobile art flows. Tourism mobilities at the museum

This texto analyses the genealogy of the historical and social phenomenon ‘mobility’,bringing about a brief discussion on the particular phenomenon of tourism mobilities, in order to provide na understanding about tourism mobilities.info:eu-repo/semantics/publishedVersio

Hibridação e pós-colonialismo

A hibridização refere-se a um modo de conhecimento e de ação associados com o híbrido. E esta última idéia denota os interstícios, a rede de relacionamentos, os lugares e as instâncias que, à medida que fundem as suas essências e experiências, geram novas produções e reproduções de si mesmos. O hibridismo é percebido por várias escolas de pensamento e por muitos autores literários como uma das principais armas contra o colonialismo. Isto é especialmente verdadeiro para os teóricos do pós-colonialismo, como Edward Said e Homi Bhabha. Se o entendimento do hibridismo é fundamental para a reflexão que os Estudos Pós-Coloniais empreendem sobre a nossa sociedade intercultural, também é verdade que essa escola de pensamento mostra-se, ela própria, híbrida desde as suas origens. Na verdade, na nossa era pós-colonial, os textos literários e até mesmo a escrita científica (histórica, sociológica, etc ) exibem uma natureza cada vez intercultural. Mas como podem estes ‘Estudos Híbridos’, de que uma manifestação recente é a Hibridologia, através de um historiador, um sociólogo, um antropólogo ou um crítico literário, detectar tais significados públicos polissémicos que conduzem a uma mais intensa comunicação intercultural? Uma das respostas possíveis pode ser a seguinte hipótese: além da leitura e escrita de saberes especializados, os conceitos comuns (um termo central na fenomenologia sociológica de Alfred Schutz), utilizados por pessoas comuns de diferentes origens culturais numa base diária, pode constituir uma das chaves para a compreensão mútua entre as diferentes culturas hoje interligadas nas nossas sociedades pós-coloniais globais

A (à) luz do panoptismo: retidão e sinuosidades das omni e pluri modernidades

A contemporaneidade pode ser entendida enquanto jogo de escondidas entre visibilidades e invisibilidades sociais. Ou seja, por vezes a sociedade deu-se a ver e descobriu-se (emitiu luz sobre si); outras vezes ocultou-se e encobriu-se (omitiu luz na sua direção). Em particular no que concerne algumas das manifestações dos diversos poderes na vida quotidiana. Este processo ocorreu em planos articulados entre si: através das visões do mundo, no nível macrossocial das estruturas; por meio das visualidades sociais, no interior do nível microssocial onde os atores sociais agem em copresença; e pela intermediação das visibilidades sociais, no seio ao nível mediador da sociedade (Andrade, 1995; 1997a). Tais emissões ou omissões de luminosidades sociais mostraram-se diferentes em períodos diacrónicos diversos, como a pré-modernidade, a modernidade e a pós-modernidade. Ora, a meu ver, estas idades do social, contrariamente ao que é defendido por algumas perspetivas filosóficas recentes, não constituem mais do que casos particulares de outras figuras da epocalidade humana mais abrangentes, como as omnimodernidades, as plurimodernidades e as intermodernidades. A seguir, procuraremos esclarecer os conceitos aqui anunciados e enunciados, simultaneamente à pesquisa de uma história e tipologia das figuras de luminosidade, que incluem tanto luzes quanto contra-luzes sociais