Grown furniture: a move towards design for sustainability

This thesis deals with the proposal that environmentally benign items of free standing furniture may be produced by the use of such well established techniques as training and grafting natural tree growth to shape. The project has been driven by the growing environmental concerns of which mankind has become aware in the late twentieth century, and which are starting to exert such a powerful influence in the twenty first. A broad history of man's use and control of natural tree growth, ranging geographically from Europe to Australia, and in size from hand held agricultural picks to eighteenth century sailing ships, is followed by a brief description of the ways in which the explosive increase in world popuanon. together with the expanding industrial activities of the Western consumer society, are feared to be threatening the stability of the natural environment. The various disasters and catastrophic accidents which have brought this situation to the attention of the general public are briefly surveyed, together with National, International and a range of Industrial responses. As one of the professions most closely concerned with the production of consumer items, the various reactions of the Design Community are similarly examined. In conclusion, the author's proposal for an experimental item of furnitureenvironmentally benign in production, use and disposal - is described and illustrated. A simple free standing three legged stool, the form of both the item itself and that of the jig required to control it's growth, are described and illustrated. The growth of examples of this, carried out on three sites across southern Britain are documented, experimental results reported and discussed. A further range of designs suitable to be produced using this method of controlling and grafting natural growth is proposed, and suggestions made for further experimentation

Realizability and recursive mathematics

Section 1: Philosophy, logic and constructivityPhilosophy, formal logic and the theory of computation all bear on problems in the foundations of constructive mathematics. There are few places where these, often competing, disciplines converge more neatly than in the theory of realizability structures. Uealizability applies recursion-theoretic concepts to give interpretations of constructivism along lines suggested originally by Heyting and Kleene. The research reported in the dissertation revives the original insights of Kleene—by which realizability structures are viewed as models rather than proof-theoretic interpretations—to solve a major problem of classification and to draw mathematical consequences from its solution.Section 2: Intuitionism and recursion: the problem of classificationThe internal structure of constructivism presents an interesting problem. Mathematically, it is a problem of classification; for philosophy, it is one of conceptual organization. Within the past seventy years, constructive mathematics has grown into a jungle of fullydeveloped "constructivities," approaches to the mathematics of the calculable which range from strict finitism through hyperarithmetic model theory. The problem we address is taxonomic: to sort through the jungle, set standards for classification and determine those features which run through everything that is properly "constructive."There are two notable approaches to constructivity; these must appear prominently in any proposed classification. The most famous is Brouwer's intuitioniam. Intuitionism relies on a complete constructivization of the basic mathematical objects and logical operations. The other is classical recursive mathematics, as represented by the work of Dekker, Myhill, and Nerode. Classical constructivists use standard logic in a mathematical universe restricted to coded objects and recursive operations.The theorems of the dissertation give a precise answer to the classification problem for intuitionism and classical constructivism. Between these realms arc connected semantically through a model of intuitionistic set theory. The intuitionistic set theory IZF encompasses all of the intuitionistic mathematics that does not involve choice sequences. (This includes all the work of the Bishop school.) IZF has as a model a recursion-theoretic structure, V(A7), based on Kleene realizability. Since realizability takes set variables to range over "effective" objects, large parts of classical constructivism appear over the model as inter¬ preted subsystems of intuitionistic set theory. For example, the entire first-order classical theory of recursive cardinals and ordinals comes out as an intuitionistic theory of cardinals and ordinals under realizability. In brief, we prove that a satisfactory partial solution to the classification problem exists; theories in classical recursive constructivism are identical, under a natural interpretation, to intuitionistic theories. The interpretation is especially satisfactory because it is not a Godel-style translation; the interpretation can be developed so that it leaves the classical logical forms unchanged.Section 3: Mathematical applications of the translation:The solution to the classification problem is a bridge capable of carrying two-way mathematical traffic. In one direction, an identification of classical constructivism with intuitionism yields a certain elimination of recursion theory from the standard mathematical theory of effective structures, leaving pure set theory and a bit of model theory. Not only are the theorems of classical effective mathematics faithfully represented in intuitionistic set theory, but also the arguments that provide proofs of those theorems. Via realizability, one can find set-theoretic proofs of many effective results, and the set-theoretic proofs are often more straightforward than their recursion-theoretic counterparts. The new proofs are also more transparent, because they involve, rather than recursion theory plus set theory, at most the set-theoretic "axioms" of effective mathematics.Working the other way, many of the negative ("cannot be obtained recursively") results of classical constructivism carry over immediately into strong independence results from intuitionism. The theorems of Kalantari and Retzlaff on effective topology, for instance, turn into independence proofs concerning the structure of the usual topology on the intuitionistic reals.The realizability methods that shed so much light over recursive set theory can be applied to "recursive theories" generally. We devote a chapter to verifying that the realizability techniques can be used to good effect in the semantical foundations of computer science. The classical theory of effectively given computational domains a la Scott can be subsumed into the Kleene realizability universe as a species of countable noneffective domains. In this way, the theory of effective domains becomes a chapter (under interpre¬ tation) in an intuitionistic study of denotational semantics. We then show how the "extra information" captured in the logical signs under realizability can be used to give proofs of classical theorems about effective domains.Section 4: Solutions to metamathematical problems:The realizability model for set theory is very tractible; in many ways, it resembles a Boolean-valued universe. The tractibility is apparent in the solutions it offers to a number of open problems in the metamathematics of constructivity. First, there is the perennial problem of finding and delimiting in the wide constructive universe those features that correspond to structures familiar from classical mathematics. In the realizability model, it is easy to locate the collection of classical ordinals and to show that they form, intuitionistically, a set rather than a proper class. Also, one interprets an argument of Dekker and Myhill to prove that the classical powerset of the natural numbers contains at least continuum-many distinct cardinals.Second, a major tenet of Bishop's program for constructivity has been that constructive mathematics is "numerical:" all the properties of constructive objects, including the real numbers, can be represented as properties of the natural numbers. The realizability model shows that Bishop's numericalization of mathematics can, in principle, be accomplished. Every set over the model with decidable equality and every metric space is enumerated by a collection of natural numbers

Army architects : The Royal Engineers and the development of building technology in the nineteenth century.

SIGLEAvailable from British Library Document Supply Centre- DSC:DX81181 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Semantic Domains and Denotational Semantics

The theory of domains was established in order to have appropriate spaces on which to define semantic functions for the denotational approach to programming-language semantics. There were two needs: first, there had to be spaces of several different types available to mirror both the type distinctions in the languages and also to allow for different kinds of semantical constructs - especially in dealing with languages with side effects; and second, the theory had to account for computability properties of functions - if the theory was going to be realistic. The first need is complicated by the fact that types can be both compound (or made up from other types) and recursive (or self-referential), and that a high-level language of types and a suitable semantics of types is required to explain what is going on. The second need is complicated by these complications of the semantical definitions and the fact that it has to be checked that the level of abstraction reached still allows a precise definition of computability

Solubility Studies of the Nafion ® perfluorosulfonated ionomer

This thesis describes an investigation into routes for the solubilisation of Nafion® membrane. Nafion® membrane in the protonated, lithium, sodium and potassium cation forms has been dissolved at high temperature and pressure in an autoclave. Solvent blends of water and either methanol, ethanol, 1-propanol or 1-butanol were used and solution concentrations of up to 15 wt% were achieved. The effect of temperature and time at temperature have been investigated for this autoclave method. Solutions made in this way have been concentrated by solvent evaporation to yield solutions of about 30 wt% Nation®. A promising method to dissolve Nafion® in a microwave acid digestion bomb in water/ alcohol blends has also been developed. Reflux dissolution has also been used to produce Nafion® solutions. Swelling experiments have been undertaken to help establish optimum solvent blends for the solubilisation process. A solubility parameter is proposed from a swelling study and is further investigated by a new procedure involving contact angle measurements. The properties of films cast from resulting Nafion® solutions and the melt flow properties of Nafion® powders in the protonated and tetrabutylammonium cation forms are also reported. The technological target of this work was to establish the ideal route for the dissolution of Nafion® membrane and the optimisation of high concentration solutions, which has been achieved

Withdrawing from History: Wordsworth, Scott, and Dickens and the Afterlife of the Scottish Enlightenment

In this project, I use Sir Walter Scott, William Wordsworth, and Charles Dickens to trace the emergence of what I call a poetics of private life. I argue that a literature of individualized, interior domesticity developed in response to the effacement of the Scottish Enlightenment and its local specificity at a time of British assimilation. In the eighteenth century, metropolitan Scotland, buoyed by hopes of cultural and economic renewal, developed and popularized antiquarian studies of local folk culture and theories of history positing telic models of societal development. Such concepts and practices were the intellectual fruits of the universities, learned societies, and philosophical circles that typified Scotland's heavily institutionalized Enlightenment. In the wake of the Act of Union, a new literature emerged, one exchanging models of universal human progress for narratives of private life. This arc coincides with Scott's renunciation of regional, historically inflected Scottish poetry in favor of three-volume fiction and Wordsworth's corresponding need to develop an increasingly autobiographical (and generically "British") Romanticism. These dual developments would significantly alter the shape of British literature for Scott's novelistic successors such as Dickens. Thus, this dissertation resituates the emergence of British Romanticism and the nineteenth-century three-volume novel both historically and geographically, within a narrative beginning in the eighteenth century, with Scotland's assimilation into an increasingly urban, homogenous Britain

Later prehistoric settlement in the Western Isles of Scotland

This study aims to establish an understanding of the nature of settlement development in the Western Isles in the period from c. 1000 BC - 800 AD. A new classification of the sites is formulated to deal with the specific Hebridean context and with the restrictions of the available evidence. This provides a framework for analysis and replaces previous schemes, imported from elsewhere in Scotland, which have tended to confuse the settlement patterns and the settlement development of the area. The large number of older excavations are reassessed in the light of both new approaches to classification and interpretation, and the evidence of recent survey and excavation. A coherent settlement sequence can be seen to emerge, showing a development of monumental architecture in the mid-lst millennium BC from a background of non-monumental domestic settlement: this monumentality persists for several centuries in the form of the atlantic roundhouses and wheelhouses before being gradually replaced by non-monumental, cellular and linear structures in the 1st millennium AD. Structural, locational and spatial analyses combine to demonstrate patterns of settlement development which show the progressive adaptation of Hebridean populations to the changing socio¬ economic context. The development of architecture is shown to be linked to contemporary social and economic processes. The environmental context of settlement development is shown to be of great significance in shaping broad trends of settlement development, while the specific responses of human groups indicate the importance of social factors. The final part of the study proposes possible models for the interpretation of settlement change. Material culture, including architecture, can be seen to be used actively in the negotiation of social relationships, both within the islands and between the islanders and the emerging states of Scotland in the 1st millennium AD