777 research outputs found
Experimental specific energy absorption rate assessment from absorption cross section measurement for far-field exposure at 2-3 GHz
Eco-Forecasting for Domestic Electricity Use
Over the past decade we have seen an increased awareness about domestic energy consumption and a growing focus on eco-feedback displays. In this paper we explore the concept of providing forecasts in such displays as a supplement to information about past usage. Our prototype, eForecast, extends the display of past electricity usage with forecasts about expected usage, electricity price, availability of wind power, and expected demand drops and peaks. Building on previous eco-feedback display research, our approach specifically enables people to use electricity at more opportune times – when it is cheap, green, or when there is an abundance of capacity. We evaluated eForecast in real world use in three domestic households for 22 weeks, where we explored potentials and limitations of forecasting for shifting electricity consumption. In this way, families were able to act in a more sustainable way – without necessarily reducing the amount of electricity consumed. Author Keywords Sustainability; forecasting; energy consumption; domesti
Widespread erosion on high plateaus during recent glaciations in Scandinavia
Glaciers create some of Earth’s steepest topography; yet, many areas that were repeatedly overridden by ice sheets in the last few million years include extensive plateaus. The distinct geomorphic contrast between plateaus and the glacial troughs that dissect them has sustained two long-held hypotheses: first, that ice sheets perform insignificant erosion beyond glacial troughs, and, second, that the plateaus represent ancient pre-glacial landforms bearing information of tectonic and geomorphic history prior to Pliocene–Pleistocene global cooling (~3.5 Myr ago). Here we show that the Fennoscandian ice sheets drove widespread erosion across plateaus far beyond glacial troughs. We apply inverse modelling to 118 new cosmogenic 10Be and 26Al measurements to quantify ice sheet erosion on the plateaus fringing the Sognefjorden glacial trough in western Norway. Our findings demonstrate substantial modification of the pre-glacial landscape during the Quaternary, and that glacial erosion of plateaus is important when estimating the global sediment flux to the oceans
Bacterial viruses enable their host to acquire antibiotic resistance genes from neighbouring cells
Prophages are quiescent viruses located in the chromosomes of bacteria. In the human
pathogen, Staphylococcus aureus, prophages are omnipresent and are believed to be responsible
for the spread of some antibiotic resistance genes. Here we demonstrate that release of
phages from a subpopulation of S. aureus cells enables the intact, prophage-containing
population to acquire beneficial genes from competing, phage-susceptible strains present in
the same environment. Phage infection kills competitor cells and bits of their DNA are
occasionally captured in viral transducing particles. Return of such particles to the prophagecontaining
population can drive the transfer of genes encoding potentially useful traits such
as antibiotic resistance. This process, which can be viewed as ‘auto-transduction’, allows
S. aureus to efficiently acquire antibiotic resistance both in vitro and in an in vivo virulence
model (wax moth larvae) and enables it to proliferate under strong antibiotic selection
pressure. Our results may help to explain the rapid exchange of antibiotic resistance genes
observed in S. aureus
A framework for implementation, education, research and clinical use of ultrasound in emergency departments by the Danish Society for Emergency Medicine
The first Danish Society for Emergency Medicine (DASEM) recommendations for the use of clinical ultrasound in emergency departments has been made. The recommendations describes what DASEM believes as being current best practice for training, certification, maintenance of acquired competencies, quality assurance, collaboration and research in the field of clinical US used in an ED
Diffusion, Fragmentation and Coagulation Processes: Analytical and Numerical Results
We formulate dynamical rate equations for physical processes driven by a
combination of diffusive growth, size fragmentation and fragment coagulation.
Initially, we consider processes where coagulation is absent. In this case we
solve the rate equation exactly leading to size distributions of Bessel type
which fall off as for large -values. Moreover, we provide
explicit formulas for the expansion coefficients in terms of Airy functions.
Introducing the coagulation term, the full non-linear model is mapped exactly
onto a Riccati equation that enables us to derive various asymptotic solutions
for the distribution function. In particular, we find a standard exponential
decay, , for large , and observe a crossover from the Bessel
function for intermediate values of . These findings are checked by
numerical simulations and we find perfect agreement between the theoretical
predictions and numerical results.Comment: (28 pages, 6 figures, v2+v3 minor corrections
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