Modelling of a standard gas mixtures generator with computational fluid dynamics

Monitoring VOC for climate change and for indoor and outdoor air quality at trace level concentrations need reference standard materials at high metrological performance. To improve this performance, the description of phenomena involved in mixtures generation by rigorous models is mandatory. A model to describe diffusion cells of a primary generator was developed and validated with experimental data. A good agreement was found between the uncertainties of measurements and calculations

Commodity Food Prices: Review and Empirics

The present paper provides a literature review of studies examining the potential causes and consequences of recent surges in food and agricultural commodity prices. Furthermore, this paper uses the structural trend methodology proposed by Koopman et al. (2009) to analyze movements in the IMF monthly commodity food price index for the period 1992(11)–2012(10) and to provide forecasts for the period 2012(11)–2014(12). The empirical results indicate that commodity food prices present seasonality and cyclicality with the longest periodicity of two years.Theempirical findings identify certain structural breaks in commodity food price series aswell as outliers. These structural breaks seem to capture the trend component of the price serieswell,while the outliers take account of temporal effects, that is, short-lived spikes. Finally, the presented forecasts show high and volatile commodity food prices

Toward the realization of reproducible AFM measurements of elastic modulus in biological samples

partially_open6The validation of the AFM method for elastic modulus E measurement in soft materials (E <5 MPa) is still missing. The interest of measurements in materials with E <5 MPa is mainly biological, including soft tissues and single cells. For the diagnosis of malignant human tumors, a change in cell elasticity, within tissues, has recently been recognized as a marker of metastatic potential. To measure a cell elasticity difference, reproducible E measurements in biological samples are needed. In this work a robust method for a metrological validation of E measurements in the range 500–5000 kPa was developed, based on the realization of thick E standard samples and on the study of the interactions between the measurement process and the sample at micro- and nano-scale. E measurement reproducibility limit of 4% has been reached. This allows designing a very sensitive and reproducible measurement of E in biological samples representing thus a powerful diagnostic tool for cancer detection.partially_openA. Demichelis; C. Divieto; L. Mortati; S. Pavarelli; G. Sassi; M. SassiDemichelis, A.; Divieto, C.; Mortati, L.; Pavarelli, S.; Sassi, G.; Sassi, M

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Interventions using behavioural insights to influence children's diet-related outcomes: a systematic review

The global prevalence of children with overweight and obesity continues to rise. Obesity in childhood has dire long-term consequences on health, social and economic outcomes. Promising interventions using behavioural insights to address obesity in childhood have emerged. This systematic review examines the effectiveness and health equity implications of interventions using behavioural insights to improve children's diet-related outcomes. The search strategy included searches on six electronic databases, reference lists of previous systematic reviews and backward searching of all included studies. One-hundred and eight papers describing 137 interventions were included. Interventions using behavioural insights were effective at modifying children's diet-related outcomes in 74% of all included interventions. The most promising approaches involved using incentives, changing defaults and modifying the physical environment. Information provision alone was the least effective approach. Health equity implications were rarely analysed or discussed. There was limited evidence of the sustainability of interventions-both in relation to their overall effectiveness and cost-effectiveness. The limited evidence on health equity, long-term effectiveness and the cost-effectiveness of these interventions limit what can be inferred for policymakers. This review synthesises the use of behavioural insights to improve children's diet-related outcomes, which can be used to inform future interventions

In-use Energy Performance Study Of Automated Smart Homes

Domestic energy demand has been high on the carbon reduction agenda for some time. Today new homes are being designed following the “fabric first” principle which is reducing heat demand, but it is shifting the design challenge to ventilation. Further energy reductions and comfort improvements are needed. It is frequently proposed that automated control systems can achieve this. However, the technologies involved are currently considered expensive and complicated. There is little published evidence of how these types of systems perform in use, which leads to scepticism. This research study aims to test the hypothesis that automated demand-controlled heating and ventilation can provide a good indoor environment while reducing energy consumption in “real-life” homes. A year-long case study was conducted using six occupied, neighbouring dwellings installed with a low-cost automated building control system. The energy consumption figures recorded were compared to the values predicted by the Standard Assessment Procedure and by a Dynamic Simulation Model, and compared to Passivhaus standard. Significant savings have been identified. The results of this study show that an automated control system can lead to very low energy, and hence low carbon homes at a price-point that would incentivise widespread role out. This means that such systems have the potential to make a considerable contribution to reducing the carbon footprint of housing stock, and hence to meeting carbon reduction targets

Food Price Volatility over the Last Decade in Niger and Malawi: Extent, Sources and Impact on Child Malnutrition

Recently, considerable attention has rightly been paid to the nutritional impact of the sharp hikes in international food prices which took place in 2007-8 and, again, in 2010-11. While sacrosanct, this growing focus has somewhat obscured the effect of other factors which do affect malnutrition in the Sub-Saharan Africa context, i.e. the long term impact of agricultural policies, huge and persistent seasonal variation in domestic food prices, and the impact of famines which still regularly stalk the continent. This paper focuses on the relative weight of these factors in explaining child malnutrition (proxied by the number of child admissions to feeding centers) in Malawi and Niger, two prototypical countries in the region. The analysis shows that the drivers of domestic food staple prices and of the ensuing child malnutrition have to be found not only – or not primarily – in the changes of international food prices but mainly in the impact of agricultural policies on food production, the persistence of a strong food price seasonality, and recurrent and often poorly attended famines. Indeed, even during years of declines in international food prices, these factors often exert a huge upward pressures on domestic food prices and child malnutrition