While some countries' building sectors have accepted and implemented public policies aimed at promoting a sustainable built environment, these measures have had little impact and change has been modest. This problem has been investigated by evaluating the concept of sustainable development in terms of its influence on environmental problems caused by the processes involved in planning, building and construction. A literature survey examining the resulting changes in public policies for a built environment produced a summary of the explanations for policy failure. The barriers to sustainable development are both general and sector specific. Policy-makers could be more effective in tackling the fragmented nature of the built environment's institutional context. Policy-making theory and past experience in planning suggest that a variety of actors should be included in the policy process, and that their knowledge should be put to good use. Those involved must develop a common understanding of what sustainable building entails, and of how it can be achieved. This requires flexibility concerning goals and procedures. One pitfall is a disproportionate focus on policy processes as against real issues. It is vital that policy processes are prioritized, sustainability presented unambiguously, and practitioners' use of research results closely monitored.Alors que dans certains pays, les industriels de la construction ont accepté et mis en oeuvre des politiques publiques visant à promouvoir un milieu bâ ti durable, ces mesures ont eu peu d'impact et les changements ont été modestes. Ce problème a été étudié en évaluant le concept de développement durable en termes de son influence sur les problèmes d'environnement posés par les processus intervenant dans la planification, la construction et les bâ timents. Une analyse de la documentation consacrée aux changements qui en ont résulté dans les politiques publiques relatives au milieu bâ ti a permis de présenter un résumé des explications des défaillances de la politique. Les obstacles au développement durable sont à la fois de nature générale et propres à ce secteur. Les décideurs pourraient être plus efficaces lorsqu'ils s'attaquent au problème de la nature fragmentée du contexte institutionnel du milieu bâ ti. La théorie de l'élaboration des politiques et l'expérience passée en matière de planification laissent à penser que plusieurs facteurs devraient être inclus dans les processus politiques et que leur connaissance devrait être mise à bon usage. Tous ceux qui sont engagés dans ce processus doivent développer une compréhension commune de ce que les bâ timents durables impliquent et expliquer comment cet objectif peut être atteint. Cela nécessite une certaine souplesse en ce qui concerne les objectifs et les procédures. La focalisation disproportionnée sur les processus politiques au détriment des vrais problèmes serait un écueil. Il est essentiel que les processus politiques soient prioritaires, que la durabilité soit présentée sans ambiguïté et que l'utilisation des résult...

Design and performance of very longwavelength GaAs/Al x Ga1−x As quantumwell infrared photodetectors J. Appl. Phys. 76, 6001 (1994); 10.1063/1.358351Long wavelength (λ1.5 μm) nativeoxidedefined InAlAsInPInGaAsP quantum well heterostructure laser diodes Success has been achieved in extending the spectral wavelength of GaAs/AIXGal _ XAs quantum-well infrared photodetectors to significantly longer wavelengths, ;1= 11-15 pm. High responsivity Rp = 0.5 A/W, high quantum efficiency rl= 12%, and high detectivity D* = 3 x 10" cm JHz/w, as well as an excellent noise equivalent temperature difference NEAT = 4 mK have been achieved at T = 50 K. High performance NEAT = 19 mK has also been achieved at an even higher temperature of T = 60 K. 5101

The longest-wavelength quantum-well infrared photodetector ever achieved, with a cutoff wavelength λc=19 μm, is demonstrated. Detailed measurements and an in-depth analysis of the noise, optical gain, detectivity, quantum efficiency, and quantum-well escape probability, are also discussed.

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This paper reviews a large body of regulatory literature and applies four major debates to the field of building regulation and control. We find that this field has attracted little attention of regulatory scholars, whilst fields such as the 'natural' or 'occupational' environment are often addressed in regulatory studies. We furthermore find that studies of building regulation and control often lack theoretical descriptions or applications. We argue that such application is necessary for a better understanding of building regulations and control.