A global perspective on aerosol from low-volatility organic compounds

Global production of organic aerosol from primary emissions of semivolatile (SVOCs) and intermediate (IVOCs) volatility organic compounds is estimated using the global chemical transport model, GEOS-Chem. SVOC oxidation is predicted to be a larger global source of net aerosol production than oxidation of traditional parent hydrocarbons (terpenes, isoprene, and aromatics). Using a prescribed rate constant and reduction in volatility for atmospheric oxidation, the yield of aerosol from SVOCs is predicted to be about 75% on a global, annually-averaged basis. For IVOCs, the use of a naphthalene-like surrogate with different high-NOx and low-NOx parameterizations produces a global aerosol yield of about 30%, or roughly 5 Tg/yr of aerosol. Estimates of the total global organic aerosol source presented here range between 60 and 100 Tg/yr. This range reflects uncertainty in the parameters for SVOC volatility, SVOC oxidation, SVOC emissions, and IVOC emissions, as well as wet deposition. The highest estimates result if SVOC emissions are significantly underestimated (by more than a factor of 2) or if wet deposition of the gas-phase semivolatile species is less effective than previous estimates. A significant increase in SVOC emissions, a reduction of the volatility of the SVOC emissions, or an increase in the enthalpy of vaporization of the organic aerosol all lead to an appreciable reduction of prediction/measurement discrepancy. In addition, if current primary organic aerosol (POA) inventories capture only about one-half of the SVOC emission and the Henrys Law coefficient for oxidized semivolatiles is on the order of 10^3 M/atm, a global estimate of OA production is not inconsistent with the top-down estimate of 140 Tg/yr by (Goldstein and Galbally, 2007). Additional information is needed to constrain the emissions and treatment of SVOCs and IVOCs, which have traditionally not been included in models

Improving ICT governance in Australian companies

This paper begins with the Australian Standard for the Corporate Governance of Information and Communication Technology (ICT) AS8015 (Standards Australia, 2005) and presents research findings that can be applied as recommendations to enhance the effective implementation of this Standard’s principles within an organisation. These recommendations relating to the principles outlined within the Standard concern such factors as, identifying and addressing issues surrounding the implementation of this Standard and the actions that could be undertaken to improve the effectiveness of ICT governance by sharply focusing upon the governance aspects of ICT within business, as opposed to the management aspect of ICT

Mobilising Social Rights in EU Economic Governance: A Pragmatic Challenge to Neoliberal Europe

A ‘constitutional asymmetry’ exists at the heart of contemporary EU socio-economic governance, privileging the economic at the expense of the social. Prevailing academic responses suggest, on the one hand, the need for radical constitutional reforms aimed at redressing this asymmetry and, on the other hand, piecemeal reforms reliant on current soft and non-binding modes of governance for the championing of social concerns. Offering a pragmatic middle way between these positions, we identify the potential within the extant constitutional settlement to pursue a rebalancing in favour of the social. In particular, we highlight the Commission’s pre-existing legal and rhetorical commitment to social rights, arguing that it might draw on the standards established by the Council of Europe’s European Committee of Social Rights and incorporate these into its economic governance mechanism, the European Semester. Such a step would usefully repoliticise socio-economic governance in the short term and promote radical reform in the long term

BIM implementation practices of construction organizations in the UK AEC industry (Second Edition paper)

The aim of this research was to investigate the implementation practices and application of BIM technology by construction organisations through the project phases from inception to operational use in the United Kingdom. The aim and objectives of the study were achieved using qualitative methodology. Semi-structured interview was used for collecting data. Secondary source of data collection included a comprehensive literature review on past and current work on BIM implementation and application across the project lifecycle. To achieve the overall aim fully, a generic Process Map was deemed best to illustrate the BIM implementation practices of construction organisations through the project phases in the UK. The BIM functions or sub-processes at each project phases of the construction process were highlighted from the interviews. Then the generic process map above linking all the BIM activities in the project was developed. The information outputs at the end of each project stage were illustrated in the Process Map. The information inputs feeding into the BIM functions at the project phases were also examined from the interviews and illustrated in the process map. The information inputs feeding into the BIM functions at the project phases were also examined from the interviews and illustrated in the Process Map

Secondary organic aerosol (SOA) formation from reaction of isoprene with nitrate radicals (NO_3)

Secondary organic aerosol (SOA) formation from the reaction of isoprene with nitrate radicals (NO3) is investigated in the Caltech indoor chambers. Experiments are performed in the dark and under dry conditions (RH<10%) using N2O5 as a source of NO3 radicals. For an initial isoprene concentration of 18.4 to 101.6 ppb, the SOA yield (defined as the ratio of the mass of organic aerosol formed to the mass of parent hydrocarbon reacted) ranges from 4.3% to 23.8%. By examining the time evolutions of gas-phase intermediate products and aerosol volume in real time, we are able to constrain the chemistry that leads to the formation of low-volatility products. Although the formation of ROOR from the reaction of two peroxy radicals (RO2) has generally been considered as a minor channel, based on the gas-phase and aerosol-phase data it appears that RO2+RO2 reaction (self reaction or cross-reaction) in the gas phase yielding ROOR products is a dominant SOA formation pathway. A wide array of organic nitrates and peroxides are identified in the aerosol formed and mechanisms for SOA formation are proposed. Using a uniform SOA yield of 10% (corresponding to Mo≅10 μg m−3), it is estimated that ~2 to 3 Tg yr−1 of SOA results from isoprene + NO3. The extent to which the results from this study can be applied to conditions in the atmosphere depends on the fate of peroxy radicals (i.e. the relative importance of RO2+RO2 versus RO2+NO3 reactions) in the nighttime troposphere

A database and tool for boundary conditions for regional air quality modeling: description and evaluation

Transported air pollutants receive increasing attention as regulations tighten and global concentrations increase. The need to represent international transport in regional air quality assessments requires improved representation of boundary concentrations. Currently available observations are too sparse vertically to provide boundary information, particularly for ozone precursors, but global simulations can be used to generate spatially and temporally varying lateral boundary conditions (LBC). This study presents a public database of global simulations designed and evaluated for use as LBC for air quality models (AQMs). The database covers the contiguous United States (CONUS) for the years 2001–2010 and contains hourly varying concentrations of ozone, aerosols, and their precursors. The database is complemented by a tool for configuring the global results as inputs to regional scale models (e.g., Community Multiscale Air Quality or Comprehensive Air quality Model with extensions). This study also presents an example application based on the CONUS domain, which is evaluated against satellite retrieved ozone and carbon monoxide vertical profiles. The results show performance is largely within uncertainty estimates for ozone from the Ozone Monitoring Instrument and carbon monoxide from the Measurements Of Pollution In The Troposphere (MOPITT), but there were some notable biases compared with Tropospheric Emission Spectrometer (TES) ozone. Compared with TES, our ozone predictions are high-biased in the upper troposphere, particularly in the south during January. This publication documents the global simulation database, the tool for conversion to LBC, and the evaluation of concentrations on the boundaries. This documentation is intended to support applications that require representation of long-range transport of air pollutants

Experimental and model estimates of the contributions from biogenic monoterpenes and sesquiterpenes to secondary organic aerosol in the southeastern United States

Atmospheric organic aerosol (OA) has important impacts on climate and human health but its sources remain poorly understood. Biogenic monoterpenes and sesquiterpenes are important precursors of secondary organic aerosol (SOA), but the amounts and pathways of SOA generation from these precursors are not well constrained by observations. We propose that the less-oxidized oxygenated organic aerosol (LO-OOA) factor resolved from positive matrix factorization (PMF) analysis on aerosol mass spectrometry (AMS) data can be used as a surrogate for fresh SOA from monoterpenes and sesquiterpenes in the southeastern US. This hypothesis is supported by multiple lines of evidence, including lab-in-the-field perturbation experiments, extensive ambient ground-level measurements, and state-of-the-art modeling. We performed lab-in-the-field experiments in which the ambient air is perturbed by the injection of selected monoterpenes and sesquiterpenes, and the subsequent SOA formation is investigated. PMF analysis on the perturbation experiments provides an objective link between LO-OOA and fresh SOA from monoterpenes and sesquiterpenes as well as insights into the sources of other OA factors. Further, we use an upgraded atmospheric model and show that modeled SOA concentrations from monoterpenes and sesquiterpenes could reproduce both the magnitude and diurnal variation of LO-OOA at multiple sites in the southeastern US, building confidence in our hypothesis. We estimate the annual average concentration of SOA from monoterpenes and sesquiterpenes in the southeastern US to be roughly 2µgm^(−3)

Foot burns: A comparative analysis of diabetic and non-diabetic patients

Introduction: Foot burns represent a small part of the body with many challenges. The impact of diabetes on clinical outcomes adds further issues in management that clinicians must consider in their management. These factors have serious implications on morbidity and long term sequelae. Our aim is to analyse epidemiological trends of foot burns and examine the differences between diabetic and non-diabetics at Concord hospital from 2014 to 2019. Methods: A retrospective audit from 2014–19 at Concord General Repatriation Hospital Burns Unit summarised patient demographics, burn injury, diabetic status, operations and length of stay. All foot burn injuries from 2014–19 of all ages and gender that attended Concord burns hospital were included in this study. Results: We treated 797 patients who presented with foot burns, of which 16.2% were diabetic. The average age was higher in diabetics (60.72 years) than non-diabetics (39.72 years) and more males suffered burns compared to females in both groups (p \u3c 0.001). There was a larger portion of elderly patients (greater than 65 years old, 15.1% of total) who sustained foot burns in the diabetic group compared to the non-diabetic group (p \u3c 0.001). The most affected season was summer (27.0%), but diabetic patients were 1.7 times more likely to sustain injury in winter than non-diabetics. Diabetics were 3.8 times more likely to have contact burns compared to non-diabetic patients (p \u3c 0.001). In a multivariable linear regression analysis, factors that contributed to increased length of stay included elderly status, place of event, diabetic status, number of operations, ICU admission, wound infection, amputation, and admission [F (16, 757 = 41.149, p \u3c 0.001, R2 = 0.465]. Conclusions: With the increase of diabetes, our multidisciplinary approach to diabetic foot care should include nursing, medical and surgical disciplines to identify patients at risk. The data highlights that a focus on prevention and education for diabetes is central to optimize glycaemic control and burn management, whilst providing a multidisciplinary network on discharge

Projected effect of 2000-2050 changes in climate and emissions on aerosol levels in China and associated transboundary transport

We investigate projected 2000–2050 changes in concentrations of aerosols in China and the associated transboundary aerosol transport by using the chemical transport model GEOS-Chem driven by the Goddard Institute for Space Studies (GISS) general circulation model (GCM) 3 at 4° × 5° resolution. Future changes in climate and emissions projected by the IPCC A1B scenario are imposed separately and together through sensitivity simulations. Accounting for sulfate, nitrate, ammonium, black carbon (BC), and organic carbon (OC) aerosols, concentrations of individual aerosol species change by −1.5 to +0.8 μg m^(−3), and PM_(2.5) levels are projected to change by about 10–20% in eastern China as a result of 2000–2050 change in climate alone. With future changes in anthropogenic emissions alone, concentrations of sulfate, BC, and OC are simulated to decrease because of assumed reductions in emissions, and those of nitrate are predicted to increase because of higher NO_x emissions combined with decreases in sulfate. The net result is a predicted reduction of seasonal mean PM_(2.5) concentrations in eastern China by 1–8 μg m^(−3) (or 10–40%) over 2000–2050. It is noted that current emission inventories for BC and OC over China are judged to be inadequate at present. Transboundary fluxes of different aerosol species show different sensitivities to future changes in climate and emissions. The annual outflow of PM_(2.5) from eastern China to the western Pacific is estimated to change by −7.0%, −0.7%, and −9.0% over 2000–2050 owing to climate change alone, changes in emissions alone, and changes in both climate and emissions, respectively. The fluxes of nitrate and ammonium aerosols from Europe and Central Asia into western China increase over 2000–2050 in response to projected changes in emissions, leading to a 10.5% increase in annual inflow of PM_(2.5) to western China with future changes in both emissions and climate. Fluxes of BC and OC from South Asia to China in spring contribute a large fraction of the annual inflow of PM_(2.5). The annual inflow of PM_(2.5) from South Asia and Southeast Asia to China is estimated to change by −8%, +281%, and +227% over 2000–2050 owing to climate change alone, changes in emissions alone, and changes in both climate and emissions, respectively. While the 4° × 5° spatial resolution is a limitation of the present study, the direction of predicted changes in aerosol levels and transboundary fluxes still provides valuable insight into future air quality