Models of design and technology and their significance for research and curriculum development

Modelling is the activity that is central to designing, and is therefore central in the designing of a school curriculum. The models of designing and of the curriculum that are formed shape both the evolution of the curriculum and its subsequent evaluation. A brief introduction charts some of the reasons for the evolution of simplistic models of designing and notes some of their dangers. The nature of problems in design and technology is discussed. Some theoretical difficulties in expressing ideas about design and technology are noted and hence the consequential merits of an empirical approach are made evident. The rigorous analysis of good practice should play an important part in research and curriculum development in design and technology, but it is crucial to recognise that such analysis will be influenced by the viewpoint (models held) by the analyst

Design and technology educational research and curriculum development: the emerging international research agenda

The publication of book derived from IDATER conferences (as distinct from Conference Proceedings) is a new venture for IDATER, which has been undertaken in order to further the debate concerning an international research agenda. It is hoped that this publication will both enable those who were not fortunate enough to be at IDATER99 and IDATER2000 to gain something of the Conference outcomes and help to prepare for IDATER2001

The nature of research into Design and Technology education

The focus of Design Curriculum Matters is the design curriculum, by which we mean not only the formal Design and Technology curriculum and its courses, but also the larger design dimension of pupils’ experience both in and beyond school. Furthermore, the Series takes the position that any education system’s formal design (or design and technology, or technology) curriculum including of course the National Curriculum version in England and Wales – is itself problematic and therefore a proper object for scrutiny

Modelling: the language of designing

Design: Occasional Papers uses DESIGN as its encompassing category. In this usage, Design is to be construed as a broad field of human endeavour and enterprise, analogous in its generality and complexity to Science and the Humanities. Still at the level of generality, but now related to professional-vocational activities, Design is also to be construed as a field that includes a diverse range of distinguishable areas of professional activity (which would include architecture, communication and graphic design, industrial design, information design, interior design, aspects of engineering desig, textiles/fashion, environmental design). At this level, Design must accommodate pluralistic conceptions: there is no single Design culture. But ‘design’ is also used as a verb. Again at the high level of generality, designing may be characterised as an intentional activity: to do with bringing about change. More specifically – and as with Design when used as a tag for a field – what ‘designing’ is intended to mean relates also to the specific area in which it is used, and by whom. The field has many specialist communities, many different languages of discourse and, within and around those, different persuasions and differing voices. Design: Occasional Papers is therefore concerned with the relations between the generic and the particular. The essential reason for publishing the Series is to provide a means whereby the differing conversational communities that are related to design may become, at the least, more accessible to each other and thereby enable the reader to take part in the running argument by which knowledge and understanding develop

Statistics of the gravitational force in various dimensions of space: from Gaussian to Levy laws

We discuss the distribution of the gravitational force created by a Poissonian distribution of field sources (stars, galaxies,...) in different dimensions of space d. In d=3, it is given by a Levy law called the Holtsmark distribution. It presents an algebraic tail for large fluctuations due to the contribution of the nearest neighbor. In d=2, it is given by a marginal Gaussian distribution intermediate between Gaussian and Levy laws. In d=1, it is exactly given by the Bernouilli distribution (for any particle number N) which becomes Gaussian for N>>1. Therefore, the dimension d=2 is critical regarding the statistics of the gravitational force. We generalize these results for inhomogeneous systems with arbitrary power-law density profile and arbitrary power-law force in a d-dimensional universe

Core of the Magnetic Obstacle

Rich recirculation patterns have been recently discovered in the electrically conducting flow subject to a local external magnetic termed "the magnetic obstacle" [Phys. Rev. Lett. 98 (2007), 144504]. This paper continues the study of magnetic obstacles and sheds new light on the core of the magnetic obstacle that develops between magnetic poles when the intensity of the external field is very large. A series of both 3D and 2D numerical simulations have been carried out, through which it is shown that the core of the magnetic obstacle is streamlined both by the upstream flow and by the induced cross stream electric currents, like a foreign insulated insertion placed inside the ordinary hydrodynamic flow. The closed streamlines of the mass flow resemble contour lines of electric potential, while closed streamlines of the electric current resemble contour lines of pressure. New recirculation patterns not reported before are found in the series of 2D simulations. These are composed of many (even number) vortices aligned along the spanwise line crossing the magnetic gap. The intensities of these vortices are shown to vanish toward to the center of the magnetic gap, confirming the general conclusion of 3D simulations that the core of the magnetic obstacle is frozen. The implications of these findings for the case of turbulent flow are discussed briefly.Comment: 14 pages, 9 figures, submitted to Journal of Turbulenc

A critical role for cystathionine-β-synthase in hydrogen sulfide-mediated hypoxic relaxation of the coronary artery

Hypoxia-induced coronary artery vasodilatation protects the heart by increasing blood flow under ischemic conditions, however its mechanism is not fully elucidated. Hydrogen sulfide (H2S) is reported to be an oxygen sensor/transducer in the vasculature. The present study aimed to identify and characterise the role of H2S in the hypoxic response of the coronary artery, and to define the H2S synthetic enzymes involved. Immunoblotting and immunohistochemistry showed expression of all three H2S-producing enzymes, cystathionine-β-synthase (CBS), cystathionine-γ-lyase (CSE) and 3-mercaptopyruvate sulfurtransferase (MPST), in porcine coronary artery. Artery segments were mounted for isometric tension recording; hypoxia caused a transient endothelium-dependent contraction followed by prolonged endothelium-independent relaxation. The CBS inhibitor amino-oxyacetate (AOAA) reduced both phases of the hypoxic response. The CSE inhibitor dl-propargylglycine (PPG) and aspartate (limits MPST) had no effect alone, but when applied together with AOAA the hypoxic relaxation response was further reduced. Exogenous H2S (Na2S and NaHS) produced concentration-dependent contraction followed by prolonged relaxation. Responses to both hypoxia and exogenous H2S were dependent on the endothelium, NO, cGMP, K+ channels and Cl−/HCO3 − exchange. H2S production in coronary arteries was blocked by CBS inhibition (AOAA), but not by CSE inhibition (PPG). These data show that H2S is an endogenous mediator of the hypoxic response in coronary arteries. Of the three H2S-producing enzymes, CBS, expressed in the vascular smooth muscle, appears to be the most important for H2S generated during hypoxic relaxation of the coronary artery. A contribution from other H2S-producing enzymes only becomes apparent when CBS activity is inhibited