McLean's Nuggets

The development of a clean, plentiful and low-cost alternative energy source is the holy grail of the 21st century. Ken Yeang looks into his crystal ball and asks whether the future could lie in nanoenergy and the proliferation of numerous personal nanogenerators - attached to buildings, individuals or under bridges. Copyright © 2009 John Wiley & Sons, Ltd.     

Contextual Counterpoint

In recent decades, conservationists and planners have co-opted contextualism, reducing it to a tool for enforcing urban conformity. Here Charles Jencks reclaims contextualism as a dynamic design strategy. He identifies four different contextual treatments that as well as ensuring continuity are potentially transformative. Copyright © 2011 John Wiley & Sons, Ltd.     

The Deep Structure of the Picturesque

The late Paul Coates was one of the first students at the Architectural Association (AA) in London to submit an international computation-based diploma, in 1969. Responsible for introducing a series of computational techniques, Coates was also the founder of the MSc in Computing and Design at the University of East London, and in 2002 the Centre for Evolutionary Computing in Architecture (CECA). In this unpublished article from 2008, which has been prepared and rewritten for publication by Christian Derix , Coates recounts his pursuit of ‘the particle physics of architecture’ - geometric rules that inform both unplanned and planned human occupation of space.     

Accuracy of black carbon measurements by a filter-based absorption photometer with a heated inlet

Long-term measurements of black carbon (BC) aerosols by filter-based absorption photometers with a heated inlet (COSMOS) in different regions have been useful in elucidating spatial variations and radiative impacts of BC. Evaluations of mass concentrations of BC (M_BC) measured by the COSMOS have been made by our previous studies through comparisons with other measurement techniques. However, how variations in the microphysical properties of BC and the co-existing light scattering aerosols affect the COSMOS measurements should be evaluated in more detail. In this study, we assessed these potential effects under various field environments in the Arctic and in the East Asia. From the slopes of the correlation plots between the M_BC values measured by the COSMOS and a single-particle soot photometer, the average accuracy of the COSMOS was estimated as ～10% in the M_BC range 1–3000?ng m^?3. On an hourly basis, the estimated sensitivity of the COSMOS M_BC values to the changes in the BC size distributions was less than 10%, within the typical variabilities of BC size at individual observation sites. The COSMOS measurements depended little on the mixing states of BC and the concentrations of co-existing light scattering aerosols, except in the maritime air masses of East Asia, where the relative abundance of sea salt to BC was very high. The M_BC measured by COSMOS also well agreed with elemental carbon measurements. Our results demonstrate the high reliability of COSMOS measurements under various environments.

Copyright © 2019 American Association for Aerosol Research     

Extrapolation of single particle soot photometer incandescent signal data

The Single Particle Soot Photometer (SP2) is an instrument for quantifying the refractory black carbon (rBC) mass of individual aerosol particles. It heats the particle’s rBC component to vaporization and quantifies the resulting visible thermal radiation to infer rBC mass. For purely technical reasons, SP2s are unable to quantify rBC mass beyond an easily adjustable limit due to eventual saturation of the electronics that record the visible light signals. Here, we evaluate an extrapolation algorithm to estimate rBC masses exceeding this upper limit in an SP2. The algorithm is based on identifying the crossing points of linear fits to unsaturated data, and using the duration of the saturated data to constrain potential errors. We find that extrapolation performance is quite insensitive to instrument parameters including laser intensity, rate of data acquisition, and particle speed through the laser. However, this approach increases uncertainty on the detection limit of the instrument, and is hence only useful in unknown aerosols for very limited extrapolation to approximately a factor of 1.5 increase in the upper mass range, corresponding to a 15% increase in the upper diameter limit. This increased range small enough that early identification of meaningful saturation during measurement campaigns remains the only tenable approach to robustly characterizing rBC mass size distributions and, in some cases, rBC mass concentrations.     

Site/Non-Site: Extending the Parameters in Contemporary Landscape

As the world teeters on the verge of environmental collapse, landscape architecture has taken on a new significance offering a longed-for sanctuary for our increasingly urbanised lives. Here, in his introduction to the issue, guest-editor Michael Spens explains how by taking its impetus from land art, landscape architecture, as an expanded field, transcends the conventional confines of site. This renders it possible to read architecture ‘as landscape, or as non-landscape, as building becomes non-site’ and the ‘site indeed materialises as the work per se’. Copyright © 2007 John Wiley & Sons, Ltd.