An investigation into usability and exclusivity issues of digital programmable thermostats

This is the pre-print version of the Article - Copyright @ 2011 Taylor & FrancisWith nearly 60% of domestic energy consumption relating to space heating, the interaction between users and their heating controls is crucial in reducing consumption. Yet, many heating controls are complex and exclude people due to the demands placed upon their capabilities in terms of vision, reach, dexterity and thinking. This study explores the scale of and reasons for user exclusion in relation to digital programmable thermostats. The Exclusion Calculator was used to estimate the percentage of the population excluded from the use of three products. Full user testing was then conducted to elicit specific usability problems of the devices. The participants were a group of 14 younger users (aged 24–44) and 10 older users (aged 62–75). The exclusion calculations underestimated the actual exclusion significantly for both age ranges (p<0.05). None of the older users were able to complete the programming of the thermostats. Additionally, the cognitive demands of these systems were considered using a subjective workload assessment method, based on the NASA Task Load Index, and were found to be excessive. In conclusion, this study makes recommendations to facilitate the design of more inclusive digital programmable thermostats. It is argued that such changes could result in reductions in domestic heat energy consumption.This work is funded by the ESPRC and Buro Happold

Improving the thermal performance of single-glazed windows using translucent granular aerogel

Copyright @ 2011 Taylor & FrancisCost-effective materials, products and installation methods are required to improve the energy efficiency of the UK's existing building stock. The aim of this paper is to assess the potential for high-performance translucent granular aerogel insulation to be retrofitted over single glazing to reduce heat loss without blocking out all of the useful natural light. In situ testing of a 10-mm-thick prototype panel, consisting of a clear twin-wall polycarbonate sheet filled with granular aerogel, was carried out and validated with steady-state calculations. Results demonstrate that an 80% reduction in heat loss can be achieved without detrimental reductions in light transmission. Payback calculations accounting for the inevitable thermal bridging from openable solutions such as roller shutters or pop-in secondary glazing suggest that a return on investment between 3.5 and 9.5 years is possible if products are consistently used over the heating season. Granular aerogel is a promising material for improving the thermal performance of existing windows. Future research will seek to map out different ways in which the material can be applied to the existing UK housing stock, identifying which systems offer the greatest potential for widespread CO2 savings over their life cycle.This work is funded by the EPSRC, Brunel University and Buro Happold Ltd

Site-Specific Methylation of Adenine in the Nuclear Genome of a Eucaryote, \u3cem\u3eTetrahymena thermophila\u3c/em\u3e

DNA in the polyploid macronucleus of the ciliated protozoan Tetrahymena thermophila contains the modified base N6-methyladenine. We identified two GATC sites which are methylated in most or all of the 45 copies of the macronuclear genome. One site is 2 kilobases 5\u27 to the histone H4-I gene, and the other is 5 kilobases 3\u27 to the 73-kilodalton heat shock protein gene. These sites are de novo methylated between 10 and 16 h after initiation of conjugation, during macronuclear anlage development. The methylation states of these two GATC sites and four other unmethylated GATC sites do not change in the DNA of cells cultured under conditions which change the activity of the genes, including logarithmic growth, starvation, and heat shock

Streamlined life cycle assessment of transparent silica aerogel made by supercritical drying

This is the post-print version of the Article. The official published version can be accessed from the link below - Copyright @ 2011 ElsevierWhen developing sustainable building fabric technologies, it is essential that the energy use and CO2 burden arising from manufacture does not outweigh the respective in-use savings. This study investigates this paradigm by carrying out a streamlined life cycle assessment (LCA) of silica aerogel. This unique, nanoporous translucent insulation material has the lowest thermal conductivity of any solid, retaining up to four times as much heat as conventional insulation, whilst being highly transparent to light and solar radiation. Monolithic silica aerogel has been cited as the ‘holy grail’ of future glazing technology. Alternatively, translucent granular aerogel is now being produced on a commercial scale. In each case, many solvents are used in production, often accompanied by intensive drying processes, which may consume large amounts of energy and CO2. To date, there has been no peer-reviewed LCA of this material conducted to the ISO 14000 standard. Primary data for this ‘cradle-to-factory gate’ LCA is collected for silica aerogel made by low and high temperature supercritical drying. In both cases, the mass of raw materials and electricity usage for each process is monitored to determine the total energy use and CO2 burden. Findings are compared against the predicted operational savings arising from retrofitting translucent silica aerogel to a single glazed window to upgrade its thermal performance. Results should be treated as a conservative estimate as the aerogel is produced in a laboratory, which has not been developed for mass manufacture or refined to reduce its environmental impact. Furthermore, the samples are small and assumptions to upscale the manufacturing volume occur without major changes to production steps or equipment used. Despite this, parity between the CO2 burden and CO2 savings is achieved in less than 2 years, indicating that silica aerogel can provide a measurable environmental benefit.This work is funded by the EPSRC, Brunel University and Buro Happold Ltd, the University of Bath is funded by the EPSRC grant EP/F018622/1

Particle-in-cell simulations of collisionless magnetic reconnection with a non-uniform guide field

Results are presented of a first study of collisionless magnetic reconnection starting from a recently found exact nonlinear force-free Vlasov–Maxwell equilibrium. The initial state has a Harris sheet magnetic field profile in one direction and a non-uniform guide field in a second direction, resulting in a spatially constant magnetic field strength as well as a constant initial plasma density and plasma pressure. It is found that the reconnection process initially resembles guide field reconnection, but that a gradual transition to anti-parallel reconnection happens as the system evolves. The time evolution of a number of plasma parameters is investigated, and the results are compared with simulations starting from a Harris sheet equilibrium and a Harris sheet plus constant guide field equilibrium

The Stellar Populations of Low-redshift Clusters

We present some preliminary results from an on-going study of the evolution of stellar populations in rich clusters of galaxies. This sample contains core line-strength measurements from 183 galaxies with b_J <= 19.5 from four clusters with ~0.04. Using predictions from stellar population models to compare with our measured line strengths we can derive relative luminosity-weighted mean ages and metallicities for the stellar populations in each of our clusters. We also investigate the Mgb'-sigma and Hbeta_G'-sigma scaling relations. We find that, consistent with previous results, Mgb' is correlated with sigma, the likely explanation being that larger galaxies are better at retaining their heavier elements due to their larger potentials. Hbeta', on the other hand, we find to be anti-correlated with sigma. This result implies that the stellar populations in larger galaxies are older than in smaller galaxies.Comment: 3 pages, 2 figures, to appear in the Proceedings of IAU Colloquium 195: "Outskirts of Galaxy Clusters: intense life in the suburbs", Torino Italy, March 12-16 200

Inaugurating Philosophy of Film Without Theory

Philosophy of film without theory is a methodology that aims to motivate and legitimise the current and future development of a range of a-, non-, and anti-theoretical ways of working at the intersection of film and philosophy. We contrast philosophy of film without theory with the main traditions of theoretically orientated philosophy of film, as well as philosophically inflected film Theory and film-philosophy. We also draw attention to the range of philosophical practices and pursuits that distinguish philosophy (in general) without theory and contemporary philosophy (in general) with its near ubiquitous theoretical presumption.&nbsp; The paper finishes with a brief introduction to the various contributions to this Special Issue of Aesthetic Investigations on Philosophy of Film Without Theory

EXIST: Mission Design Concept and Technology Program

The Energetic X-ray Imaging Survey Telescope (EXIST) is a proposed very large area coded aperture telescope array, incorporating 8m^2 of pixellated Cd-Zn-Te (CZT) detectors, to conduct a full-sky imaging and temporal hard x-ray (10-600 keV) survey each 95min orbit. With a sensitivity (5sigma, 1yr) of ~0.05mCrab (10-150 keV), it will extend the ROSAT soft x-ray (0.5-2.5keV) and proposed ROSITA medium x-ray (2-10 keV) surveys into the hard x-ray band and enable identification and study of sources ~10-20X fainter than with the ~15-100keV survey planned for the upcoming Swift mission. At ~100-600 keV, the ~1mCrab sensitivity is 300X that achieved in the only previous (HEAO-A4, non-imaging) all-sky survey. EXIST will address a broad range of key science objectives: from obscured AGN and surveys for black holes on all scales, which constrain the accretion history of the universe, to the highest sensitivity and resolution studies of gamma-ray bursts it will conduct as the Next Generation Gamma-Ray Burst mission. We summarize the science objectives and mission drivers, and the results of a mission design study for implementation as a free flyer mission, with Delta IV launch. Key issues affecting the telescope and detector design are discussed, and a summary of some of the current design concepts being studied in support of EXIST is presented for the wide-field but high resolution coded aperture imaging and very large area array of imaging CZT detectors. Overall mission design is summarized, and technology development needs and a development program are outlined which would enable the launch of EXIST by the end of the decade, as recommended by the NAS/NRC Decadal Survey.Comment: 14 pages, 8 figures, 2 tables. PDF file only. Presented at SPIE (Aug. 2002) and to appear in Proc. SPIE, vol. 485

Northern Lambda Nord Communique, Vol.14, No.10 [11] (December 1993)

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