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21.
Future bottlenecks in international river basins: where transboundary institutions,population growth and hydrological variability intersect 总被引:1,自引:0,他引:1
Using global data, this article examines the nexus of transboundary flood events and future social vulnerability. Which international river basins are forecast to experience an increase in both hydrological variability and population in the future, but currently lack institutional provisions to deal with these shared events? Concentrations of elevated risk are found in several basins in Central Asia, Central America and Central Africa. The article ends by highlighting transboundary basins that merit further investigation and possibly additional institution building to reduce urban flood risk. 相似文献
22.
Michael J. Walker Kirstin Gray Christopher Hopley David Bell Peter Colwell Peter Maynard Duncan Thorburn Burns 《Food Analytical Methods》2012,5(4):874-880
Morpholine is a precursor of carcinogenic nitrosamines and although the possibility of their formation in the human stomach
after ingestion of morpholine-treated apples is reported as highly unlikely morpholine has not been authorised as a food additive
in the EU. Methods for its detection are required since it is permitted in other jurisdictions and may be present on food
through direct treatment of fruit with waxes containing the compound, through steam treatment during processing or from packaging.
Methods using derivatising agents with the inclusion of UV chromophores such as dansyl chloride yield good separation and
high sensitivity but with mass spectrometric fragment ions predominantly originated from the derivatising group rather than
the morpholine moiety. An amine acetylation derivatisation method is proposed from which fragment ions originating from the
morpholine group are detected using widely available GC–MS. With full validation, a forensically robust confirmation of the
presence of morpholine via its N-acetyl derivative is possible in support of regulatory analysis. 相似文献
23.
Mitch J. Duncan Camille Short Mahbub Rashid Nicoleta Cutumisu Corneel Vandelanotte Ronald C. Plotnikoff 《Building Research & Information》2015,43(5):646-658
Office workers are commonly targeted in interventions to modify their sitting behaviour, yet there is limited evidence of the correlates of breaks in sitting to inform intervention development. This study identifies the individual, workplace and spatial configuration correlates of the frequency of breaks in sitting (number/hour) in office workers (n?=?5531) stratified by office type (private-enclosed, shared, open plan). All behaviours and potential correlates were measured via self-report using an online cross-sectional survey. Regression analyses revealed age was the only socio-demographic characteristic associated with frequency of breaks in sitting in all office types. Greater job autonomy and local connectivity were positively associated with frequency of breaks in sitting in shared and open-plan offices. In open-plan offices co-worker proximity was negatively associated with frequency of breaks in sitting. Co-worker visibility was positively associated with frequency of breaks in sitting in all office types. This study demonstrates that individual, workplace and spatial configuration factors are all associated with the frequency of breaks in sitting and that these relationships differ by office type. These observations extend prior studies that have only examined correlates at a single level (e.g. the individual). This evidence could be useful to guide future interventions in the design of workplaces to increase breaks in sitting and workers’ physical activity. 相似文献
24.
Toru Inui Chris Chau Kenichi Soga Duncan Nicolson Nick O’Riordan 《Canadian Metallurgical Quarterly》2011,137(10):958-967
The embodied energy (EE) and gas emissions of four design alternatives for an embankment retaining wall system are analyzed for a hypothetical highway construction project. The airborne emissions considered are carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), sulphur oxides (SOX), and nitrogen oxides (NOX). The process stages considered in this study are the initial materials production, transportation of construction machineries and materials, machinery operation during installation, and machinery depreciations. The objectives are (1)?to determine whether there are statistically significant differences among the structural alternatives; (2)?to understand the relative proportions of impacts for the process stages within each design; (3)?to contextualize the impacts to other aspects in life by comparing the computed EE values to household energy consumption and car emission values; and (4)?to examine the validity of the adopted EE as an environmental impact indicator through comparison with the amount of gas emissions. For the project considered in this study, the calculated results indicate that propped steel sheet pile wall and minipile wall systems have less embodied energy and gas emissions than cantilever steel tubular wall and secant concrete pile wall systems. The difference in CO2 emission for the retaining wall of 100?m length between the most and least environmentally preferable wall design is equivalent to an average 2.0?L family car being driven for 6.2?million miles (or 62 cars with a mileage of 10,000??miles/year for 10?years). The impacts in construction are generally notable and careful consideration and optimization of designs will reduce such impacts. The use of recycled steel or steel pile as reinforcement bar is effective in reducing the environmental impact. The embodied energy value of a given design is correlated to the amount of gas emissions. 相似文献
25.
Silicone membranes to inhibit water uptake into thermoset polyurethane shape‐memory polymer conductive composites 下载免费PDF全文
Electroactive shape memory polymer (SMP) composites capable of shape actuation via resistive heating are of interest for various biomedical applications. However, water uptake into SMPs will produce a depression of the glass transition temperature (Tg) resulting in shape recovery in vivo. While water actuated shape recovery may be useful, it is foreseen to be undesirable during early periods of surgical placement into the body. Silicone membranes have been previously reported to prevent release of conductive filler from an electroactive polymer composite in vivo. In this study, a silicone membrane was used to inhibit water uptake into a thermoset SMP composite containing conductive filler. Thermoset polyurethane SMPs were loaded with either 5 wt % carbon black or 5 wt % carbon nanotubes, and subsequently coated with either an Al2O3‐ or silica‐filled silicone membrane. It was observed that the silicone membranes, particularly the silica‐filled membrane, reduced the rate of water absorption (37°C) and subsequent Tg depression versus uncoated composites. In turn, this led to a reduction in the rate of recovery of the permanent shape when exposed to water at 37°C. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41226. 相似文献
26.
Andrew C. Weems Jeffery E. Raymond Kevin T. Wacker Tiffany P. Gustafson Brandis Keller Karen L. Wooley Duncan J. Maitland 《应用聚合物科学杂志》2015,132(23)
Three microparticle additives, tungsten (W), zirconium oxide (ZrO2) , and barium sulfate (BaSO4) were selected to enhance the radio‐opacity in shape memory polymer (SMP) foam biomaterials. The addition of filler causes no significant alterations of glass transition temperatures, density of the materials increases, pore diameter decreases, and total volume recovery decreases from approximately 70 times in unfilled foams to 20 times (4% W and 10% ZrO2). The addition of W increases time to recovery; ZrO2 causes little variation in time to shape recovery; BaSO4 increases the time to recovery. On a 2.00 mean X‐ray density (mean X.D.) scale, a GDC coil standard has a mean X.D. of 0.62 ; 4% W enhances the mean X.D. to 1.89, 10% ZrO2 to 1.39 and 4% BaSO4 to 0.74. Radio‐opacity enhancing additives could be used to produce SMP foams with controlled shape memory kinetics, low density , and enhanced X ‐ray opacity for medical materials. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42054. 相似文献
27.
28.
Shape memory polymers (SMPs) are smart materials that can remember a primary shape and can return to this primary shape from a deformed secondary shape when given an appropriate stimulus. This property allows them to be delivered in a compact form via minimally invasive surgeries in humans, and deployed to achieve complex final shapes. Here we review the various biomedical applications of SMPs and the challenges they face with respect to actuation and biocompatibility. While shape memory behavior has been demonstrated with heat, light and chemical environment, here we focus our discussion on thermally stimulated SMPs. 相似文献
29.
James McIntosh Andrew Flanagan Nora Madden Maurice Mulcahy Lawrence Dargan Michael Walker Duncan Thorburn Burns 《International Journal of Food Science & Technology》2011,46(8):1569-1574
The only current effective treatment for coeliac disease (CD) is a lifelong diet that is as free from gluten as possible. This study provides baseline evidence to inform future interventions of benefit to CD sufferers by examining awareness of CD issues by food servers and preparation staff, assessing their claims to provide gluten‐free foods by analysis of a meal concurrently sampled. While the majority of attempts to purchase a ‘gluten‐free’ meal on request in restaurants were successful, some 10% of all samples contained gluten, 2.7% between 21 and 100 mg kg?1, and 7.7% >100 mg kg?1 and two unsatisfactory samples were purchased from so‐called coeliac‐friendly restaurants. These findings were consistent with those obtained previously by Collin et al. [Alimentary Pharmacology & Therapeutics 19 (2004) 1277], Størsrud et al. [European Food Research & Technology 217 (2003) 481], Gélinas et al. [International Journal of Food Science & Technology 43 (2008) 1245] for cross contamination with gluten. Staff confidence, ‘gluten‐free’ notices, signs and menu choices were no guarantee of risk‐free dining for CD sufferers. Based on our findings we suggest the need for further training, specifically for chefs and managers. 相似文献
30.
In this study, we examine the idea of localism in the context of housing policy and as mediated by the experience of devolution in England and Scotland. After considering arguments for adopting localism in principle, we examine the meaning and limitations of the concept when account is taken of the real nature of housing systems. This forms the basis for a consideration of the experience of localism in the context of social housing provision. We conclude that the implementation of localism by UK policy-makers has exhibited shortcomings and the emerging interpretation of localism may lead to policy dumping rather than enhanced real local autonomy. 相似文献