Participatory design and participatory development: a comparative review

This paper examines literature in the twin domains of participatory interactive systems design and participatory approaches to international development. As interactive systems are increasingly promoted as a possible means of achieving international development goals, designers generally agree that participatory design approaches should be applied. However, review of the literature reveals that these two different traditions have more complex relationships, and questions must be asked about: the aims of participation, the forms of participation that are being advocated, and the skills and strategies required of practitioners. The findings suggest that successful integration of participatory interactive systems design into development will require careful reflection on the nature of development and the approaches adopted.</p

Adapting participatory and agile software methods to participatory rural development

This paper presents observations from a project that combines participatory rural development methods with participatory design techniques to support a farmers’ co-operative in Madhya Pradesh, India</p

Giant Impact Induced Atmospheric Blow-Off

Previous calculations indicate that the Earth suffered impacts from objects up to Mars size. Such a giant impact may have produced a temporary ejecta-based ring that accreted to form the Moon. To simulate the surface waves from such events we approximated the cratering source as a buried pressurized sphere. For a 10^27 J impactor we calculated the resulting surface wave using the mode summation method of Sato et al.. For such an impact, the solid Earth free-surface velocity above, and antipodal to, the source achieves 2.6 and 1.9 km/s. Such large ground motions pump the atmosphere and result in upward particle motions which cause the atmosphere to be accelerated to excess of the escape velocity (11.2 km/s) at high altitudes. For a 1.3 × 10^32 J Moon-forming impact we calculate that ~50% of the Earth's atmosphere is accelerated to escape

Stability analysis and simulations of coupled bulk-surface reaction–diffusion systems

In this article, we formulate new models for coupled systems of bulk-surface reaction–diffusion equations on stationary volumes. The bulk reaction–diffusion equations are coupled to the surface reaction–diffusion equations through linear Robin-type boundary conditions. We then state and prove the necessary conditions for diffusion-driven instability for the coupled system. Owing to the nature of the coupling between bulk and surface dynamics, we are able to decouple the stability analysis of the bulk and surface dynamics. Under a suitable choice of model parameter values, the bulk reaction–diffusion system can induce patterning on the surface independent of whether the surface reaction–diffusion system produces or not, patterning. On the other hand, the surface reaction–diffusion system cannot generate patterns everywhere in the bulk in the absence of patterning from the bulk reaction–diffusion system. For this case, patterns can be induced only in regions close to the surface membrane. Various numerical experiments are presented to support our theoretical findings. Our most revealing numerical result is that, Robin-type boundary conditions seem to introduce a boundary layer coupling the bulk and surface dynamics

Shock wave induced vaporization of porous solids

Strong shock waves generated by hypervelocity impact can induce vaporization in solid materials. To pursue knowledge of the chemical species in the shock-induced vapors, one needs to design experiments that will drive the system to such thermodynamic states that sufficient vapor can be generated for investigation. It is common to use porous media to reach high entropy, vaporized states in impact experiments. We extended calculations by Ahrens [J. Appl. Phys. 43, 2443 (1972)] and Ahrens and O'Keefe [The Moon 4, 214 (1972)] to higher distentions (up to five) and improved their method with a different impedance match calculation scheme and augmented their model with recent thermodynamic and Hugoniot data of metals, minerals, and polymers. Although we reconfirmed the competing effects reported in the previous studies: (1) increase of entropy production and (2) decrease of impedance match, when impacting materials with increasing distentions, our calculations did not exhibit optimal entropy-generating distention. For different materials, very different impact velocities are needed to initiate vaporization. For aluminum at distention (m)<2.2, a minimum impact velocity of 2.7 km/s is required using tungsten projectile. For ionic solids such as NaCl at distention <2.2, 2.5 km/s is needed. For carbonate and sulfate minerals, the minimum impact velocities are much lower, ranging from less than 1 to 1.5 km/s

Supplier search in industrial clusters: Sheffield metal working in the 1990s

Industrial clusters can be characterised by high levels of personal interaction between the owners/managers of firms. It has been argued that within industrial clusters community and firm tend to merge. One result of the notion of a cluster as a community is that it might be expected that personal interaction between members of the community will have an important influence on intra-cluster trading patterns. Whereas there appears to be a number of anecdotal stories of the impact of the 'personal' upon the 'economic' within clusters we do not know whether such relationships are uniquely part of cluster behaviour or whether they are found more widely within the industrial system. The paper reports the result of a new interview survey of seventy small metal working firms in the Sheffield metal working cluster in the UK. Although dealing with a traditional industrial sector the analysis is focused upon contemporary business patterns. It explores the ways in which owner/managers of small metal working firms search for new suppliers. In the empirical analysis the search process is conceptualised as being characterised by two stages: the identification of potential new suppliers and the selection of a specific new supplier. The research is in undertaken in two parts. It first measures the role of the personal networks of the owner/managers of small firms in the identification and selection of suppliers. Second, the research examines whether personal factors are more important in the identification and selection of within cluster suppliers than in the identification and selection of suppliers based outside the cluster. It is shown that, overall, personal networks are of major significance in the identification of suppliers and that information received from third parties are more important than direct contacts between the owner/manager and the potential supplier. However, in the selection decision, price and availability are dominant considerations and personal factors such as trust and reputation of only minor significance. It was not possible to identify a cluster effect in disaggregation of the data to separate out the relationships with cluster suppliers and relationships with suppliers based outside the cluster. There was no evidence that personal factors play a more important role in the establishment of within cluster links. In sum, personal networks are important in the identification of within cluster links but they are equally important in the establishment of links outside the cluster. This suggests that the importance of personal interaction within clusters has been overplayed.

Timescales for the development of methanogenesis and free gas layers in recently-deposited sediments of Arkona Basin (Baltic Sea)

Arkona Basin (southwestern Baltic Sea) is a seasonally-hypoxic basin characterized by the presence of free methane gas in its youngest organic-rich muddy stratum. Through the use of reactive transport models, this study tracks the development of the methane geochemistry in Arkona Basin as this muddy sediment became deposited during the last 8 kyr. Four cores are modeled each pertaining to a unique geochemical scenario according to their respective contemporary geochemical profiles. Ultimately the thickness of the muddy sediment and the flux of particulate organic carbon are crucial in determining the advent of both methanogenesis and free methane gas, the timescales over which methanogenesis takes over as a dominant reaction pathway for organic matter degradation, and the timescales required for free methane gas to form