Quantifying effects of using thermally thin fuel approximations on modelling fire propagation in woody fuels

In this paper, we quantify the effects of the thermally thin fuel approximations commonly made in numerical models that eliminate temperature gradients within a heated object. This assumption is known to affect the modeled ignition and burn behavior, but there is little research on its impact, particularly in larger fuels or in numerical models including moisture and chemical decomposition of fuels. We begin by comparing modeled to observed ignition times and burn rates. To constrain variability in the material properties of wood and focus on variability caused by fuels assumed to be thermally thin, we conduct experiments using thermogravimetric analysis (TGA) for samples of lodgepole pine. From these data, we derive material properties via optimization with genetic algorithms. We consider burnout experiments on large, woody fuels to confirm ignition time and mass loss rates for a range of fuel specimens and then recreate them with a numerical modeling platform to validate the model. Once validated, we use the model to explore the significance of thermally thin fuel assumptions by performing the same analyses on fuels assumed to be thermally thick and thermally thin. We quantify the ignition times and mass loss rates but also examine differences in thermal inertia of ignited fuels and how the compositions of fuels vary spatially and temporally. We find that fuels of around 1mm in thickness of both approximations show very similar ignition times, mass loss rates, and surface temperature histories. Fuels any larger will quickly show differences

An evolving model of design culture

This paper addresses the difficulty of bringing about culture change; it is based on a project that is examining the role of design management in the context of large one-off projects in the mining and construction industries. A model of culture taking into account technology, values and organisation is presented. In different situations, different facets of the model - values, technology or organization - turn out to be most significant in understanding the state of the culture in that situation. But we then also need to make the link between culture and behaviour, before any intervention can be planned. This is particularly so when the practice of design management is desired by a company to become more value added to a company's projects

Effect of Social Responsibility Information, Source of Information, and Type of Media on Consumer Perceptions of Product Recalls

A three-variable full factorial experimental design was performed to study consumer's perceptions of a company after they had learned the company had made a product recall. The three variables studied were the effects of favorable remarks about the company's social responsibility in acting quickly to recall the defective product,the effect of the medium used to present the information, and the effect of the source of the information. The results of the study indicated that favorable social responsibility did influence subject's attitudes toward the company in a positive manner. Media type also seemed to influence subject's responses. Subjects who received the product recall information through print ncdia tended to view the company in a more favorable light. Although the inclusion of social responsibility information did influence subject's attitudes, the effects of media type and source of information also appear to influence consumer's thinking when they learn of a product recall.Business Administratio

Techno-social systems in organizations

The introduction of new electronic tools or alterations to existing ones can easily founder on user reluctance unless due consideration is given to how the technology fits into users' lives and meets their needs. This is a commonplace for technology developers yet all too often at the point of implementation, such factors are forced into second place by the glamour of the new. This paper discusses such a history in an industrial setting and describes how a team of engineers and social scientists applied a systems model to explaining the relevant cultural factors behind user reluctance in this case. The model describes the techno-social system in terms of dynamic tensions between the technology itself, the organisation of work in various settings within the company and the values, such as decisiveness, held by workers and promoted by the company. The model uncovered often unspoken and unacknowledged aspects of the nature of users' problems using a systems discourse that engineers and technicians found it easy to relate to. © 2005/2006 (this paper), the author(s

La capital poética de América

América del Sur es un continente sin mito, sin esa palabra primera que indica una destinación. No por esa realidad ineludible se encuentra sin palabra, ya que cuenta con una herencia, que viene en las lenguas Castellana y Portuguesa. Es através de ellas que hereda la latinidad. América del Sur es heredera de la pietas latina cantada en la Eneida de Virgilio. La reunión de la Eneida con América da origen a Amereida. En el poema de Amereida, obra colectiva en cuyo blanco actuante aparecen unos planos que forman parte del poema como tal, siendo parte del aporte hecho por la arquitectura al poema. Ellos lo hacen entrar en la arena poética, América del Sur entra en el blanco poético de la página. Es la extensión del continente la que entra en el campo poético. Esto permite leer una proposición primera: la América poética es el concreto continente que le concierne a quienes lo habitan. La poesía por otra parte ha abordado la interrogante de la relación poesía y realidad. Su respuesta es la construcción de la Phalène, donde el poeta es el portador de la fiesta, es una poesía hecha por todos, concitada por el juego. De este modo se crea el acto poético donde la palabra poética surge y queda en medio de la vida y la extensión, constituyendo el lugar. De esta manera se ha constituido un espacio en el cual se han vinculado palabra y extensión poesía y arquitectura, la extensión del continente y el acto poético. Son los arquitectos quienes vinculan palabra poética y extensión orientada, palabra y posición. Esto es posible porque originan la obra en la contemplación del acto de habitar. Trayendo a presencia la complejidad del espacio arquitectónico por medio de la abstracción del croquis y el texto. A quien origina de este modo la obra, le es posible darle cabida a la poesía, porque su obrar con fundamento, es con palabra. Volviendo a esta tierra sin mito la poesía propone la travesía. Atravesar el continente, padecer su extensión y erigir una obra de arquitectura que es una donación. La donación es la clave que garantiza una nueva relación con la extensión, ya no de explotación o dominio, propio del espacio colonial, sino nacida de una contemplación que es anterior a todo uso. Obra de donación que construye una relación de gratitud con la tierra. La obra de arquitectura debe garantizar la donación, lo que la lleva a desarrollar una arquitectura efímera, que por sí misma no se impone, sino que incluye a quien la recibe, permitiéndole la decisión de su permanencia o desaparición. La arquitectura construye aquello que es lo fijo en el espacio para habitar. Lo fijo ha sido tradicionalmente construido como lo perdurable. Se propone una nueva posibilidad, la construcción de lo fijo que es el espacio arquitectónico de un modo efímero. Ahora el continente sud americano no tiene un interlocutor directo que asuma su unidad y totalidad, que pueda recibir las proposiciones que apuntan a su constitución. La primera figura de unidad de este continente es su propia extensión, aquello que se hace presente en los seis mapas que contiene el poema Amereida. En la tarea de construir esta posibilidad de destinación en la latinidad, en este principiar latino que incluye a todos quienes residen en suelo americano, se requiere de un nombre que signe este principiar. Así la poesía adelanta un nombre y un lugar: una Capital Poética, Santa Cruz de la Sierra en Bolivia. La poesía avanza palabras de una posible realidad, así indica una capital poética y juega su posibilidad en una concreta ubicación en Santa Cruz de la Sierra. La arquitectura inicia su construcción con las travesías para lo cual propone un primer modo de ser de la capital poética: todo lugar de Sud América está en una relación equivalente con esta capital, en cuanto a ser una donación que canta la gratitud a la tierra. De este modo la Capital poética es un horizonte que está al inicio de la construcción de las obras y al término de ellas ya que al permanecer o desaparecer cantan su posibilidadSouth America is a continent without myth: it does not have that initial word which indicates a destination. Given this inescapable reality it is not without words, it has the heritage that comes with the Castilian and Portuguese languages. Through these languages its inheritance is Latin. South America inherits the Latin pietas sung by Virgil in the Aeneid. The joining of the Aeneid with America gives origin to Amereida. The active whiteness of the poem Amereida supports diagrams that form a substantial part of this collective work, making them integral to the architecture of the poem. They allow South America to enter the poetic arena via the poetic white of the page. It is the extent of the continent that enters the poetic field. This permits the reading of an initial proposition: poetic America is the actual continent that concerns its inhabitants. On the other hand this poetry addresses the relation between poetry and reality. Its answer is a construction in which the poet is the bearer of the fiesta, la Phalène: a poetry made by all that is structured as a game. In this way a poetic act is created where the poetic word comes to light and mediates life and extent, establishing place. In this manner a space is constituted in which are grounded word and extent, poetry and architecture, the extent of the continent and the poetic act. Architects ground the poetic word and the oriented extent, word and position. This is possible because they give origin to a work by contemplating the act of inhabitation. They bring into presence the complexity of the architectonic act by way of the abstraction of sketch and text. It is possible for those who generate a work in this way to give room to poetry, because their work has a foundation, it has a word of origin. Returning to this land without myth, poetry proposes the travesía: a crossing of the continent, endurance of its extent, and the erection of a work of architecture that is a gift. The gift is the key that guarantees a new relation with this extent, so that it is not born of exploitation or dominion like colonial space, but of a contemplation that precedes all use. This work that is a gift builds a relationship of gratitude with the land. The work of architecture must guarantee this gift, and thus there arises an ephemeral architecture that does not impose itself, but considers those who receive it, allowing them to decide its permanence or transience. Architecture builds what is fixed about the space of inhabitation. What is fixed has traditionally been constructed as something that endures. A new possibility is proposed: building the fixed, i.e. the architectonic space, in an ephemeral way. Now the South American continent does not have a direct interpreter who can assume its unity and totality, and receive propositions concerning its constitution. The primary figure of unity of this continent is its own extent, presented in the six maps that the poem Amereida contains. The task of constructing this possibility of Latin destination, of fostering this Latin act of beginning that includes all who reside on American soil, requires a name that signals this beginning. Thus poetry proposes a name and a place: a Poetic Capital, Santa Cruz de la Sierra in Bolivia. Poetry puts forward words of a possible reality, thus indicating a poetic capital and venturing its possibility in an actual location, Santa Cruz de la Sierra. Architecture initiates the construction of the poetic capital with the travesías, proposing the primary way in which it plays this role: every place of travesía in South America has an equivalent relation to the poetic capital in being a gift that sings of gratitude to the land. In this way the Poetic Capital is a horizon at the beginning and end of the construction of the travesía works of architecture, because in remaining or disappearing they sing of its possibility