Out-of-pile burnout experiments in a full-scale simulation of an irradiation rig in a HIFAR hollow fuel element facility.

Flow measurement and burnout experiments were performed in an out-of-pile test rig which simulates the conditions of UO sub 2 irradiation rig in a hollow fuel element facility of the HIFAR reactor. One per cent of the coolant flow in the fuel element passed through the irradiation rig. A burnout heat flux of 90 W cm -2 was observed at the surface of an electrically-heated dummy irradiation can. When the coolant flow rate in the irradiation rig was increased by a factor of 2.5 the burnout heat flux rose by 30 per cent to 117 W cm - 2. A simple modification to the supporting frame for the cans improved the burnout heat flux by 3 per cent at 1 per cent of the coolant flow but enhanced it by 17 per cent at 2.5 per cent of the coolant flow. Of ten burnout events observed eight were located upstream of the end of the heated length of the can. The burnout results form a self-consistent credible set of data and provide a rational basis for the establishment of maximum permissible operating heat fluxes in irradiation rigs of the type simulated. Recommendations are made for the practical application of the results

Effects of intraduodenal protein on appetite, energy intake, and antropyloroduodenal motility in healthy older compared with young men in a randomized trial

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The botanical biofiltration of VOCs with active airflow: is removal efficiency related to chemical properties?

© 2019 Elsevier Ltd Botanical biofiltration using active green walls is showing increasing promise as a viable method for the filtration of volatile organic compounds (VOCs) from ambient air; however there is a high level of heterogeneity reported amongst VOC removal efficiencies, and the reasons for these observations have yet to be explained. Comparisons of removal efficiencies amongst studies is also difficult due to the use of many different VOCs, and systems that have been tested under different conditions. The current work describes a procedure to determine whether some of these differences may be related to the chemical properties of the VOCs themselves. This work used an active green wall system to test the single pass removal efficiency (SPRE) of nine different VOCs (acetone, benzene, cyclohexane, ethanol, ethyl acetate, hexane, isopentane, isopropanol and toluene) and explored which chemical properties were meaningful predictor variables of their biofiltration efficiencies. Ethanol was removed most efficiently (average SPRE of 96.34% ± 1.61), while benzene was least efficiently removed (average SPRE of 19.76% ± 2.93). Multiple stepwise linear regression was used to determine that the dipole moment and molecular mass were significant predictors of VOC SPRE, in combination accounting for 54.6% of the variability in SPREs amongst VOCs. The octanol water partition coefficient, proton affinity, Henry's law constant and vapour pressure were not significant predictors of SPRE. The most influential predictor variable was the dipole moment, alone accounting for 49.8% of the SPRE variability. The model thus allows for an estimation of VOC removal efficiency based on a VOC's chemical properties, and supports the idea that system optimisation could be achieved through methods that promote both VOC partitioning into the biofilter's aqueous phase, and substrate development to enhance adsorption.

Quantum Imaging with Incoherently Scattered Light from a Free-Electron Laser

The advent of accelerator-driven free-electron lasers (FEL) has opened new avenues for high-resolution structure determination via diffraction methods that go far beyond conventional x-ray crystallography methods. These techniques rely on coherent scattering processes that require the maintenance of first-order coherence of the radiation field throughout the imaging procedure. Here we show that higher-order degrees of coherence, displayed in the intensity correlations of incoherently scattered x-rays from an FEL, can be used to image two-dimensional objects with a spatial resolution close to or even below the Abbe limit. This constitutes a new approach towards structure determination based on incoherent processes, including Compton scattering, fluorescence emission or wavefront distortions, generally considered detrimental for imaging applications. Our method is an extension of the landmark intensity correlation measurements of Hanbury Brown and Twiss to higher than second-order paving the way towards determination of structure and dynamics of matter in regimes where coherent imaging methods have intrinsic limitations

The dynamics of risk perceptions and precautionary behavior in response to 2009 (H1N1) pandemic influenza

<p>Abstract</p> <p>Background</p> <p>The trajectory of an infectious disease outbreak is affected by the behavior of individuals, and the behavior is often related to individuals' risk perception. We assessed temporal changes and geographical differences in risk perceptions and precautionary behaviors in response to H1N1 influenza.</p> <p>Methods</p> <p>1,290 US adults completed an online survey on risk perceptions, interests in pharmaceutical interventions (preventive intervention and curative intervention), and engagement in precautionary activities (information seeking activities and taking quarantine measures) in response to H1N1 influenza between April 28 and May 27 2009. Associations of risk perceptions and precautionary behaviors with respondents' sex, age, and household size were analyzed. Linear and quadratic time trends were assessed by regression analyses. Geographic differences in risk perception and precautionary behaviors were evaluated. Predictors of willingness to take pharmaceutical intervention were analyzed.</p> <p>Results</p> <p>Respondents from larger households reported stronger interest in taking medications and engaged in more precautionary activities, as would be normatively predicted. Perceived risk increased over time, whereas interest in pharmaceutical preventive interventions and the engagement in some precautionary activities decreased over time. Respondents who live in states with higher H1N1 incidence per population perceived a higher likelihood of influenza infection, but did not express greater interests in pharmaceutical interventions, nor did they engage in a higher degree of precautionary activities. Perceived likelihood of influenza infection, willingness to take medications and engagement in information seeking activities were higher for women than men.</p> <p>Conclusions</p> <p>Perceived risk of infection and precautionary behavior can be dynamic in time, and differ by demographic characteristics and geographical locations. These patterns will likely influence the effectiveness of disease control measures.</p

Coordinated optimization of visual cortical maps (I) Symmetry-based analysis

In the primary visual cortex of primates and carnivores, functional architecture can be characterized by maps of various stimulus features such as orientation preference (OP), ocular dominance (OD), and spatial frequency. It is a long-standing question in theoretical neuroscience whether the observed maps should be interpreted as optima of a specific energy functional that summarizes the design principles of cortical functional architecture. A rigorous evaluation of this optimization hypothesis is particularly demanded by recent evidence that the functional architecture of OP columns precisely follows species invariant quantitative laws. Because it would be desirable to infer the form of such an optimization principle from the biological data, the optimization approach to explain cortical functional architecture raises the following questions: i) What are the genuine ground states of candidate energy functionals and how can they be calculated with precision and rigor? ii) How do differences in candidate optimization principles impact on the predicted map structure and conversely what can be learned about an hypothetical underlying optimization principle from observations on map structure? iii) Is there a way to analyze the coordinated organization of cortical maps predicted by optimization principles in general? To answer these questions we developed a general dynamical systems approach to the combined optimization of visual cortical maps of OP and another scalar feature such as OD or spatial frequency preference.Comment: 90 pages, 16 figure

Atmospheric Evolution

Earth's atmosphere has evolved as volatile species cycle between the atmosphere, ocean, biomass and the solid Earth. The geochemical, biological and astrophysical processes that control atmospheric evolution are reviewed from an "Earth Systems" perspective, with a view not only to understanding the history of Earth, but also to generalizing to other solar system planets and exoplanets.Comment: 34 pages, 3 figures, 2 tables. Accepted as a chapter in "Encyclopaedia of Geochemistry", Editor Bill White, Springer-Nature, 201

Advanced optical imaging in living embryos

Developmental biology investigations have evolved from static studies of embryo anatomy and into dynamic studies of the genetic and cellular mechanisms responsible for shaping the embryo anatomy. With the advancement of fluorescent protein fusions, the ability to visualize and comprehend how thousands to millions of cells interact with one another to form tissues and organs in three dimensions (xyz) over time (t) is just beginning to be realized and exploited. In this review, we explore recent advances utilizing confocal and multi-photon time-lapse microscopy to capture gene expression, cell behavior, and embryo development. From choosing the appropriate fluorophore, to labeling strategy, to experimental set-up, and data pipeline handling, this review covers the various aspects related to acquiring and analyzing multi-dimensional data sets. These innovative techniques in multi-dimensional imaging and analysis can be applied across a number of fields in time and space including protein dynamics to cell biology to morphogenesis

Views of addiction neuroscientists and clinicians on the clinical impact of a ‘Brain Disease Model of Addiction’

Addiction is increasingly described as a "chronic and relapsing brain disease". The potential impact of the brain disease model on the treatment of addiction or addicted individuals' treatment behaviour remains uncertain. We conducted a qualitative study to examine: (i) the extent to which leading Australian addiction neuroscientists and clinicians accept the brain disease view of addiction; and (ii) their views on the likely impacts of this view on addicted individuals' beliefs and behaviour. Thirty-one Australian addiction neuroscientists and clinicians (10 females and 21 males; 16 with clinical experience and 15 with no clinical experience) took part in 1 h semi-structured interviews. Most addiction neuroscientists and clinicians did not uncritically support the use of brain disease model of addiction. Most were cautious about the potential for adverse impacts on individuals' recovery and motivation to enter treatment. While some recognised the possibility that the brain disease model of addiction may provide a rationale for addicted persons to seek treatment and motivate behaviour change, Australian addiction neuroscientist and clinicians do not assume that messages about "diseased brains" will always lead to increased treatment-seeking and reduced drug use. Research is needed on how neuroscience research could be used in ways that optimise positive outcomes for addicted persons