20,652 research outputs found
Life cycle analysis of the environmental impact of different cabinet designs
The design of refrigerated display cabinets greatly affects their
subsequent environmental impact. To control this impact, a designer must
primarily consider the operating efficiency of a cabinet. However, less
account is taken of the materials used to make the cabinet, nor the
construction techniques used. These both have a significant effect on the
environmental impact of different cabinets outside the use phase of their
life cycle. Initial construction impact, remanufacturability and
recyclability are all affected. Given the ubiquity of the display cabinet
in the retail sector, it is important to assess their lifetime impact in
toto. This is particularly so with the increasing implementation of the
WEEE directive in member states. Three typical refrigerated display
cabinets are examined in this paper, all offering the same function, but
manufactured with quite different constructions and materials. The mass of
materials in each cabinet was determined experimentally and the methods of
assembly examined. The stages in the life of each cabinet were then
modelled and life cycle analyses performed. To compare the efficiency of
the cabinets in terms of their environmental impact, the Eco Indicator
Points/litre of refrigerated space/day were determined in each case. When
combined with the energy performance (kWh/litre/day) this provides a good
measure of the overall environmental impact of a cabinet and a way of
choosing between different models that nominally provide the same
refrigeration function. Different end of life scenarios, and improvements
in the choice of materials, were also investigated depending on the type of
construction
The human superior colliculus: Neither necessary, nor sufficient for consciousness?
Non-invasive neuroimaging in humans permits direct investigation of the potential role for mesodiencephalic structures in consciousness. Activity in the superior colliculus can be correlated with the contents of consciousness, but it can be also identified for stimuli of which the subject is unaware; and consciousness of some types of visual stimuli may not require the superior colliculus
Proto-Brown Dwarf Disks as Products of Protostellar Disk Encounters
The formation of brown dwarfs via encounters between proto-stars has been
confirmed with high-resolution numerical simulations with a restricted
treatment of the thermal conditions. The new results indicate that young brown
dwarfs (BDs) formed this way are disk-like and often reside in multiple
systems. The newly-formed proto-BDs disks are up to 18 AU in size and spin
rapidly making small-scale bipolar outflows, fragmentation and the possible
formation of planetary companions likely as have recently been observed for
BDs. The object masses range from 2 to 73 Jupiter masses, distributed in a
manner consistent with the observed sub-stellar initial mass function. The
simulations usually form multiple BDs on eccentric orbits about a star. One
such system was hierarchical, a BD binary in orbit around a star, which may
explain recently observed hierarchical systems. One third of the BDs were
unbound after a few thousand years and interactions among orbiting BDs may
eject more or add to the number of binaries. Improvements over prior work
include resolution down to a Jupiter mass, self-consistent models of the
vertical structure of the initial disks and careful attention to avoid
artificial fragmentation.Comment: 4 pages, 3 figures, accepted for publication in ApJ Letter
Extruding the vortex lattice: two reacting populations of dislocations
A controllable soft solid is realised in vortex matter in a type II
superconductor. The two-dimensional unit cell area can be varied by a factor of
in the solid phase, without a change of crystal symmetry offering easy
exploration of extreme regimes compared to ordinary materials. The capacity to
confine two-dimensional vortex matter to mesoscopic regions provides an arena
for the largely unexplored metallurgy of plastic deformation at large density
gradients. Our simulations reveal a novel plastic flow mechanism in this driven
non-equilibrium system, utilising two distinct, but strongly interacting,
populations of dislocations. One population facilitates the relaxation of
density; a second aids the relaxation of shear stresses concentrated at the
boundaries. The disparity of the bulk and shear moduli in vortex matter ensures
the dislocation motion follows the overall continuum flow reflecting density
variation
Effect of Night Blinds on Open Integral Display Cabinets
The impact of night blinds on the product temperature performance and electrical energy consumption of an integral open multi-deck cabinet is investigated in this paper. The cabinet was tested at various environmental conditions to establish the impact of ambient temperature on the effectiveness of the blind in reducing the energy consumption of the cabinet during night-time operation. The cabinet was tested over a range of temperatures between 20 °C and 35 °C at a constant moisture content. The results indicate that the use of night blinds could produce energy savings of between 10% and 22% calculated on the basis of a 24 hour period of operation with the blind lowered for 12 hours out of the 24 hours. These energy savings lead to pay-back periods of between 2 and 4 years. The savings reduced with increasing ambient temperature due to the increase in the impact of infiltration and conduction across the blind at higher temperatures
Analog voicing detector responds to pitch
Modified electronic voice encoder /Vocoder/ includes an independent analog mode of operation in addition to the conventional digital mode. The Vocoder is a bandwidth compression equipment that permits voice transmission over channels, having only a fraction of the bandwidth required for conventional telephone-quality speech transmission
Potential for Solar Energy in Food Manufacturing, Distribution and Retail
The overall aim of the study was to assess the potential for increasing the use of solar energy in the food sector. For comparative purposes the study also included an assessment of the benefits that could arise from the use of other renewable energy sources, and the potential for more effective use of energy in food retail and distribution. Specific objectives were to: i) establish the current state of the art in relevant available solar technology; ii) identify the barriers for the adoption of solar technology; iii) assess the potential for solar energy capture; iv) appraise the potential of alternative relevant technologies for providing renewable energy; v) assess the benefits from energy saving technologies; vi) compare the alternative strategies for the next 5-10 years and vii) Consider the merits of specific research programmes on solar energy and energy conservation in the food sector.
To obtain the views of the main stakeholders in the relevant food and energy sectors on the opportunities and barriers to the adoption of solar energy and other renewable energy technologies by the food industry, personal interviews and structured questionnaires tailored to the main stakeholders (supermarkets, consultants for supermarket design; energy and equipment suppliers) were used. The main findings from
the questionnaires and interviews are:
- Key personnel in supermarkets and engineers involved in the design of supermarkets are aware of the potential contribution of renewable energy technologies and other energy conservation measures to energy conservation and environmental impact reduction in the food industry. A number of supermarket chains have implemented such technologies at pilot scale to gain operating experience, and more importantly, for marketing reasons, to gain competitive advantage through a green image.
- From installations to date in the UK the most notable are a 600 kW wind turbine at a Sainsbury's distribution centre in East Kilbride and a 60 kWp photovoltaic array at a Tesco store in Swansea.
- The main barrier to the application of renewable energy technologies in the food sector is the capital cost. Even though significant progress has been made towards the improvement of the energy conversion efficiencies of photovoltaic technologies (PVs) and reduction in their cost, payback periods are still far too long, for them to become attractive to the food industry.
- Wind energy can be more attractive than PVs in areas of high wind speed. Apart from relatively high cost, the main barrier to the wide application of wind turbines for local power generation is planning restrictions. This technology is more attractive for application in food distribution centres that are normally located outside build-up areas where planning restrictions can be less severe than in urban areas. In these applications it is likely that preference will be for large wind turbines of more than 1.0 MW power generation capacity as the cost of generation per unit power reduces with the size of the turbine
Comment on Bramwell et al, "Universal Fluctuations in Correlated Systems"
This is a comment on "Universal Fluctuations in Correlated Systems", by
Bramwell et al, Phys. Rev. Lett., 84, 3744 (2000.Comment: To appear in Phys. Rev. Let
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