Where is the chromospheric response to conductive energy input from a hot pre-flare coronal loop?

Before the onset of a flare is observed in hard X-rays there is often a pro- longed pre-flare or pre-heating phase with no detectable hard X-ray emission but pronounced soft X-ray emission suggesting that energy is being released and deposited into the corona and chromosphere already at this stage. This work analyses the temporal evolution of coronal source heating and the chromospheric response during this pre-heating phase to investigate the origin and nature of early energy release and transport during a solar flare. Simultaneous X-ray, EUV, and microwave observations of a well observed flare with a prolonged pre-heating phase are analysed to study the time evolution of the thermal emission and to determine the onset of particle acceleration. During the 20 minutes duration of the pre-heating phase we find no hint of accelerated electrons, neither in hard X-rays nor in microwave emission. However, the total energy budget during the pre-heating phase suggests that energy must be supplied to the flaring loop to sustain the observed temperature and emission measure. Under the assumption of this energy being transported toward the chromosphere via thermal conduc- tion, significant energy deposition at the chromosphere is expected. However, no detectable increase of the emission in the AIA wavelength channels sensitive to chromospheric temperatures is observed. The observations suggest energy release and deposition in the flaring loop before the onset of particle acceleration, yet a model in which energy is conducted to the chromosphere and subsequent heating of the chromosphere is not supported by the observations

A 3D machine vision method for non-invasive assessment of respiratory function

Copyright © 2015 John Wiley & Sons, Ltd. Background: Respiratory function testing is important for detecting and monitoring illness, however, it is difficult for some patients, such as the young and severely ill, to perform conventional tests that require cooperation and/or patient contact. Method: A new method was developed for non-contact breathing measurement, employing photometric stereo to capture the surface topography of the torso of an unconstrained subject. The surface is integrated to calculate time-dependent volume changes during respiration. Results: The method provides a useful means of continuously measuring volume changes during respiration with high spatial and temporal resolution. The system was tested by comparison with pneumotachometry equipment and a clear periodic signal, of a frequency corresponding to the reference data, was observed. Conclusion: The approach is unique in performing breathing monitoring (with potential diagnostic capability) for unconstrained patients in virtually any lighting conditions (including darkness during sleep) and in a non-contact, unobtrusive (i.e. using imperceptible light) fashion. Copyright © 2015 John Wiley & Sons, Ltd

The Physicist's Guide to the Orchestra

An experimental study of strings, woodwinds (organ pipe, flute, clarinet, saxophone and recorder), and the voice was undertaken to illustrate the basic principles of sound production in music instruments. The setup used is simple and consists of common laboratory equipment. Although the canonical examples (standing wave on a string, in an open and closed pipe) are easily reproduced, they fail to explain the majority of the measurements. The reasons for these deviations are outlined and discussed.Comment: 11 pages, 10 figures (jpg files). Submitted to European Journal of Physic

Demanding stories: television coverage of sustainability, climate change and material demand

This paper explores the past, present and future role of broadcasting, above all via the medium of television, in shaping how societies talk, think about and act on climate change and sustainability issues. The paper explores these broad themes via a focus on the important but relatively neglected issue of material demand and opportunities for its reduction. It takes the outputs and decision-making of one of the world’s most influential broadcasters, the BBC, as its primary focus. The paper considers these themes in terms of stories, touching on some of the broader societal frames of understanding into which they can be grouped. Media decision-makers and producers from a range of genres frequently return to the centrality of ‘story’ in the development, commissioning and production of an idea. With reference to specific examples of programming, and drawing on interviews with media practitioners, the paper considers the challenges of generating broadcast stories that can inspire engagement in issues around climate change, and specifically material demand. The concluding section proposes actions and approaches that might help to establish material demand reduction as a prominent way of thinking about climate change and environmental issues more widely. This article is part of the themed issue ‘Material demand reduction’

Koalas use a novel vocal organ to produce unusually low-pitched mating calls

SummaryDuring the breeding season, male koalas produce ‘bellow’ vocalisations that are characterised by a continuous series of inhalation and exhalation sections, and an extremely low fundamental frequency (the main acoustic correlate of perceived pitch) [1]. Remarkably, the fundamental frequency (F0) of bellow inhalation sections averages 27.1 Hz (range: 9.8–61.5 Hz [1]), which is 20 times lower than would be expected for an animal weighing 8 kg [2] and more typical of an animal the size of an elephant (Supplemental figure S1A). Here, we demonstrate that koalas use a novel vocal organ to produce their unusually low-pitched mating calls

MoonBEAM A Beyond Earth-Orbit GRB Detector for Multi-Messenger Astronomy

No abstract availabl

Quantized charge transport through a static quantum dot using a surface acoustic wave

We present a detailed study of the surface acoustic wave mediated quantized transport of electrons through a split gate device containing an impurity potential defined quantum dot within the split gate channel. A new regime of quantized transport is observed at low RF powers where the surface acoustic wave amplitude is comparable to the quantum dot charging energy. In this regime resonant transport through the single-electron dot state occurs which we interpret as turnstile-like operation in which the traveling wave amplitude modulates the entrance and exit barriers of the quantum dot in a cyclic fashion at GHz frequencies. For high RF powers, where the amplitude of the surface acoustic wave is much larger than the quantum dot energies, the quantized acoustoelectric current transport shows behavior consistent with previously reported results. However, in this regime, the number of quantized current plateaus observed and the plateau widths are determined by the properties of the quantum dot, demonstrating that the microscopic detail of the potential landscape in the split gate channel has a profound influence on the quantized acoustoelectric current transport.Comment: 9 page