Fuel spray diagnostics

Several laser measurement methods are being studied to provide the capability to make droplet size and velocity measurements under a variety of spray conditions. The droplet sizing interferometer (DSI) promises to be a successful technique because of its capability for rapid data acquisition, compilation and analysis. Its main advantage is the ability to obtain size and velocity measurements in air-fuel mixing studies and hot flows. The existing DSI at NASA Lewis is a two-color, two-component system. Two independent orthogonal measurements of size and velocity components can be made simultaneously. It also uses an off-axis large-angle light scatter detection. The fundamental features of the system are optics, signal processing and data management system. The major component includes a transmitter unit, two receiver units, two signal processors, two data management systems, two Bragg cell systems, two printer/plotters, a laser, power supply and color monitor

Fuel Spray Diagnostics

Fundamental experimental data base for turbulent flow mixing models is provided and better prediction of the more complex turbulent chemical reacting flows. Analytical application to combustor design is provided and a better fundamental understanding of the combustion process

Flux Formulation of DFT on Group Manifolds and Generalized Scherk-Schwarz Compactifications

A flux formulation of Double Field Theory on group manifold is derived and applied to study generalized Scherk-Schwarz compactifications, which give rise to a bosonic subsector of half-maximal, electrically gauged supergravities. In contrast to the flux formulation of original DFT, the covariant fluxes split into a fluctuation and a background part. The latter is connected to a $2D$-dimensional, pseudo Riemannian manifold, which is isomorphic to a Lie group embedded into O($D,D$). All fields and parameters of generalized diffeomorphisms are supported on this manifold, whose metric is spanned by the background vielbein $E_A{}^I \in$ GL($2D$). This vielbein takes the role of the twist in conventional generalized Scherk-Schwarz compactifications. By doing so, it solves the long standing problem of constructing an appropriate twist for each solution of the embedding tensor. Using the geometric structure, absent in original DFT, $E_A{}^I$ is identified with the left invariant Maurer-Cartan form on the group manifold, in the same way as it is done in geometric Scherk-Schwarz reductions. We show in detail how the Maurer-Cartan form for semisimple and solvable Lie groups is constructed starting from the Lie algebra. For all compact embeddings in O($3,3$), we calculate $E_A{}^I$.Comment: 40 pages, no figures, minor changes, published versio

A geometric formulation of exceptional field theory

We formulate the full bosonic SL(5) exceptional field theory in a coordinate-invariant manner. Thereby we interpret the 10-dimensional extended space as a manifold with $\mathrm{SL}(5)\times\mathbb{R}^+$-structure. We show that the algebra of generalised diffeomorphisms closes subject to a set of closure constraints which are reminiscent of the quadratic and linear constraints of maximal seven-dimensional gauged supergravities, as well as the section condition. We construct an action for the full bosonic SL(5) exceptional field theory, even when the $\mathrm{SL}(5)\times\mathbb{R}^+$-structure is not locally flat.Comment: 46 page

Double Field Theory on Group Manifolds in a Nutshell

We give a brief overview of the current status of Double Field Theory on Group Manifolds (DFTWZW). Therefore, we start by reviewing some basic notions known from Double Field Theory (DFT) and show how they extend/generalize into the framework of Double Field Theory on Group Manifolds. In this context, we discuss the relationship between both theories and the transition from DFTWZW to DFT. Furthermore, we address some open questions and present an outlook into our current research.Comment: Proceedings prepared for the "Workshop on Geometry and Physics", November 2016, Ringberg Castle, Germany; v2: references adde

On the Lexical Integrity Hypothesis and its (In)accurate Predictions

The Lexical Integrity Hypothesis (LIH) holds that lexical items are syntactic atoms, which implies that neither their segments nor their semantic components are accessible to syntax. LIH is, thus, a double-faced hypothesis, since its predictions are relevant for both the syntax-lexicon interface and the morphology-syntax distinction, and specifically the controversial issue of whether or not morphology is an independent component of the Grammar. Both sides of LIH are addressed in this paper through a series of syntactic tests (movement, scope, modification, anaphora, ellipsis, coordination), which are shown to often give different results depending on whether the grammatical units targeted are semantic components (and lack phonological features) or morphological segments. LIH is shown to be only partially wrong. Its failures, which cannot be dismissed, are shown not to be random, since, to a large extend, they depend on the grammatical properties of the relevant components of lexical items.La hipótesis de la integridad léxica (HIL) sostiene que las palabras son átomos sintácticos, lo que implica que ni sus segmentos ni sus componentes semánticos son accesibles a la sintaxis. La hipótesis posee, en consecuencia, dos caras, ya que sus predicciones son relevantes tanto para la interfaz léxico-sintaxis como para la distinción morfología-sintaxis, y en particular en relación con la controvertida cuestión de si la morfología constituye o no un componente independiente de la Gramática. Ambas caras de la hipótesis son abordadas en este trabajo a través de una serie de pruebas sintácticas (movimiento, ámbito, modificación, anáfora, elipsis, coordinación), que dan lugar a resultados diversos en función de si las unidades afectadas son componentes semánticos (y carecen, por tanto, de rasgos fonológicos) o son segmentos morfológicos. Se defiende aquí que la HIL es solo parcialmente falsa. Sus fallos, que no pueden ser desestimados, no son tampoco arbitrarios, ya que en buena medida están en función de las propiedades gramaticales de los componentes de las piezas léxicas afectadas.A Hipótese da Integridade Lexical (LIH) defende que os itens lexicais são átomos sintáticos, o que implica que nem os seus segmentos nem os seus componentes semânticos são acessíveis à sintaxe. A LIH é, assim, uma hipótese de dupla face, uma vez que as suas previsões são relevantes para a interface sintaxe-léxico e para a distinção morfologia- sintaxe, assim como, mais especificamente, para a questão controversa da existência ou não da morfologia como uma componente independente da Gramática. Ambos os lados da LIH são abordados neste artigo a partir de uma série de testes sintáticos (movimento, escopo, modificação, anáfora, elipse, coordenação), que muitas vezes geram resultados diferentes, dependendo de as unidades gramaticais visadas serem componentes semânticas (e sem traços fonológicos) ou segmentos morfológicos. A LIH é apresentada para ser apenas parcialmente errada. As suas falhas, que não podem ser ignoradas, demonstram não são aleatórias, uma vez que, em grande medida, dependem das propriedades gramaticais dos componentes relevantes dos itens lexicais

Una renovación de la geografía regional mundial

La publication en 1981 de l'ouvrage Geografia de la Sociedad Humana -dirigé par Enric Lluch- a eu une grande répercussion et encore aujourd'hui joue un r6le de premier plan dans la bibliographie géographique espagnole. Jusqu'h ce moment-la il n'y avait pas de contributions espagnoles à la géographie d'une aussi grande ampleur. En premier lieu, cet ouvrage de réferénce est analysé d'un point de vue méthodologique et historique. Puis on étudie en détail le contenu de chacun des huit volumes.The publication in 1981 of the work Geografia de la Sociedad Humana -edited by Enric Lluch- had a great impact and, still today, it plays a significative role in the Spanish geographical literature. Until that moment there was a lack of contributions with such a wide scope in Spanish geography. First, this reference work is analyzed from a historical and methodological perspective. Afterwards, a careful study of the contents of each of the eight volumes is made

Generalized Metric Formulation of Double Field Theory on Group Manifolds

We rewrite the recently derived cubic action of Double Field Theory on group manifolds [arXiv:1410.6374] in terms of a generalized metric and extrapolate it to all orders in the fields. For the resulting action, we derive the field equations and state them in terms of a generalized curvature scalar and a generalized Ricci tensor. Compared to the generalized metric formulation of DFT derived from tori, all these quantities receive additional contributions related to the non-trivial background. It is shown that the action is invariant under its generalized diffeomorphisms and 2D-diffeomorphisms. Imposing additional constraints relating the background and fluctuations around it, the precise relation between the proposed generalized metric formulation of DFT${}_\mathrm{WZW}$ and of original DFT from tori is clarified. Furthermore we show how to relate DFT${}_\mathrm{WZW}$ of the WZW background with the flux formulation of original DFT.Comment: 28 pages, no figures, minor change

Advances in the Analysis of Spanish Exclamatives

'Advances in the Analysis of Spanish Exclamatives' is the first book entirely devoted to Spanish exclamatives, a special sentence type often overlooked by contemporary linguists and neglected in standard grammatical descriptions. The seven essays in this volume, each by a leading specialist on the topic, scrutinize the syntax, as well as the semantic and pragmatic aspects, of exclamations on theoretical grounds. The book begins by summarizing, commenting on, and evaluating previous descriptive and theoretical contributions on Spanish exclamatives. This introductory overview also contains a detailed classification of Spanish exclamative grammatical types, along with an analysis of their main properties