‘Fourth places’: the Contemporary Public Settings for Informal Social Interaction among Strangers.

This paper introduces ‘fourth places’ as an additional category of informal social settings alongside ‘third places’ (Oldenburg 1989). Through extensive empirical fieldwork on where and how social interaction among strangers occurs in the public and semi-public spaces of a contemporary masterplanned neighbourhood, this paper reveals that ‘fourth places’ are closely related to ‘third places’ in terms of social and behavioural characteristics, involving a radical departure from the routines of home and work, inclusivity, and social comfort. However, the activities, users, locations and spatial conditions that support them are very different. They are characterized by ‘in-betweenness’ in terms of spaces, activities, time and management, as well as a great sense of publicness. This paper will demonstrate that the latter conditions are effective in breaking the ‘placelessness’ and ‘fortress’ designs of newly designed urban public spaces and that, by doing so, they make ‘fourth places’ sociologically more open in order to bring strangers together. The recognition of these findings problematizes well-established urban design theories and redefines several spatial concepts for designing public space. Ultimately, the findings also bring optimism to urban design practice, offering new insights into how to design more lively and inclusive public spaces. Keywords: ‘Fourth places’, Informal Public Social Settings, Social Interaction, Strangers, Public Space Design

Carbon Nanotube Solar Cells

We present proof-of-concept all-carbon solar cells. They are made of a photoactive side of predominantly semiconducting nanotubes for photoconversion and a counter electrode made of a natural mixture of carbon nanotubes or graphite, connected by a liquid electrolyte through a redox reaction. The cells do not require rare source materials such as In or Pt, nor high-grade semiconductor processing equipment, do not rely on dye for photoconversion and therefore do not bleach, and are easy to fabricate using a spray-paint technique. We observe that cells with a lower concentration of carbon nanotubes on the active semiconducting electrode perform better than cells with a higher concentration of nanotubes. This effect is contrary to the expectation that a larger number of nanotubes would lead to more photoconversion and therefore more power generation. We attribute this to the presence of metallic nanotubes that provide a short for photo-excited electrons, bypassing the load. We demonstrate optimization strategies that improve cell efficiency by orders of magnitude. Once it is possible to make semiconducting-only carbon nanotube films, that may provide the greatest efficiency improvement

Defining public open spaces: an investigation framework to inform planning and design decision-making processes

Typomorphological analysis has been used to study building types, but it is seldom applied to open spaces. This paper argues that the same systematic and rigorous approach can be applied to define public open spaces. It explores the potential of the application of a systematic analysis of types and forms to define urban landscapes. Drawing on existing literature, this paper identifies specific attributes related to urban landscape elements including formal and spatial aspects. This paper highlights the potential of open space networks to respond to the contemporary challenges facing urban designers working to create better places to live in. This paper contributes to the field of design research through the development of a method of survey and analysis to inform design decision-making processes. Its significance lies in proposing a comprehensive framework to contribute to a more detailed definition of urban landscape character and inform the development of sustainable urban strategies

No effect of ketoprofen and meloxicam on bone graft ingrowth: a bone chamber study in goats.

Contains fulltext : 71116.pdf (publisher's version ) (Open Access)BACKGROUND AND PURPOSE: There is increasing awareness that non-steroidal anti-inflammatory drugs (NSAIDs), and especially the cyclooxygenase-2 (COX-2) selective ones, may retard bone healing. We have used NSAIDs (indomethacin for at least 7 days) to prevent heterotopic ossification after acetabular reconstructions using impacted bone grafts. The long-term clinical results have been satisfying, making it difficult to believe that there is an important negative effect of NSAIDs on graft incorporation. We studied the effect of two different NSAIDs on bone and tissue ingrowth in a bone chamber model in goats, using autograft, rinsed allograft, and allograft that had been rinsed and subsequently irradiated. METHODS: 9 goats received no NSAIDs, 9 received ketoprofen, and 9 received meloxicam--all for 6 weeks. In each goat 6 bone chambers were implanted: 2 filled with autograft, 2 with rinsed allograft, and 2 with allograft that had been rinsed and irradiated. The amount of bone ingrowth and total tissue ingrowth was compared between the groups. RESULTS: There were no statistically significant differences in bone ingrowth between the different groups. Also, no differences in bone ingrowth were found with respect to the type of graft used. Furthermore, there was no statistically significant difference in the total amount of ingrowth of fibrous tissue between the treatment groups. INTERPRETATION: No differences in bone ingrowth in titanium bone chambers could be detected with both ketoprofen and meloxicam compared to untreated control animals. This confirms our hypothesis that the effect of NSAIDs on the incorporation and ingrowth of bone graft is limited

Abundance-range size relationships of breeding and wintering birds in Britain: a comparative analysis

When microstructures are characterized by transmission electron microscopy (TEM), the interpretation of results is facilitated if the material can be sectioned in defined orientations. In the case of fibres, it is especially useful if transverse and longitudinal sections can be obtained reliably. Here we describe a procedure for orienting spider silk and other flexible fibres for TEM investigation. Prior to embedding in epoxy resin, the silk is wound around a notched support made from polyester film. No glue is required. After the silk and its supporting film have been embedded and the resin has been cured the film can be peeled away to reveal nearly perfectly orientated silk threads. Both transverse and longitudinal sections can then be cut with a microtome. The method can be extended to obtain sections at any intermediate orientation

Nanostructural features of a spider dragline silk as revealed by electron and X-ray diffraction studies

Transmission electron microscopy (TEM) and X-ray diffraction (XRD) were used to examine the nanostructure of a natural polymer-a spider dragline silk-that has potential applications as an engineering material. The silk studied was collected from the cob-web weaving spider Latrodectus hesperus. Single crystal and polycrystalline electron diffraction patterns indicate the presence of crystals with a bimodal size distribution, in the range of 2 nm and 40-120 nm. The chain axis of the smaller crystals is more strictly aligned with the fiber axis than that of the larger crystals. Lattice parameters for the orthogonal unit cell are: a=9.4 Å (interchain), b=7.0 Å (dipeptide, fiber axis) and c=10.8 Å (intersheet). A fine structure in single crystal electron diffraction patterns indicates possible composition-dependent lattice strains. Results of tensile tests of the spider dragline silk are reported, and a simple model is presented linking the observed nanostructural features to the force-elongation response of this material. © 2006 Elsevier Ltd. All rights reserved.</p