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11.
Smoke-free policies have been an important tobacco control intervention. As recently as 20 years ago, few communities required workplaces and hospitality venues to be smoke-free, but today approximately 11% of the world's population live in countries with laws that require these places to be smoke-free. This paper briefly summarises important milestones in the history of indoor smoke-free policies, the role of scientific research in facilitating their adoption, a framework for smoke-free policy evaluation and industry efforts to undermine regulations. At present, smoke-free policies centre on workplaces, restaurants and pubs. In addition, many jurisdictions are now beginning to implement policies in outdoor areas and in shared multiunit housing settings. The future of smoke-free policy development depends on credible scientific data that documents the health risks of secondhand smoke exposure. Over the next 20 years smoke-free policies will very likely extend to outdoor and private areas, and changes in the types of tobacco products that are consumed may also have implications for the nature and scope of the smoke-free policies of the future. 相似文献
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This paper compares empirically the predictive performance of two different methods of software reliability prediction: `neural networks' and `recalibration for parametric models'. Both methods were claimed to predict as good or better than the conventional parametric models that have been used-with limited results so far. Each method applied its own predictability measure, impeding a direct comparison. To be able to compare, this study uses a common predictability measure and common data-sets. This study reveals that neural networks are not only much simpler to use than the recalibration method, but that they are equal or better trend (variable term) predictors. The neural network prediction is further improved by preparing the data with a running average, instead of the traditionally used averages of grouped data points. Neural network predictions do not depend on prior known models. Off-the-shelf neural network software tools make it easy to apply the method 相似文献
14.
Jorge Laine Joaquin Brito Francisco Severino Germán Castro Patricia Tacconi Simón Yunes José Cruz 《Catalysis Letters》1990,5(1):45-54
The effect of prereduction on CO oxidation activity of unsupported copper-chromite oxide catalysts was examined. Results were found to be in good agreement with two mechanisms for a surface copper enrichment due to CO prereduction which produced an activity increase in the copper-chromite catalyst. 相似文献
15.
Joaquin Requena Rodrigo Moreno Jose S. Moya 《Journal of the American Ceramic Society》1989,72(8):1511-1513
The slip casting technique has been revealed as a powerful method to obtain multilayer composites close to theoretical density. From zeta potential and viscosity measurements of Al2 O3 and Al2 O3 /ZrO2 (4 vol% ZrO2 ) suspensions, the corditions for the preparation of multilayer composites by slip casting have been determined. A microstructural analysis of the different layers by scanning electron microscopy is also reported. 相似文献
16.
A sensitivity analysis of 0.1 mu m MOSFETs to manufacturing fluctuations has been carried out. The analysis reveals that the electrical parameter sensitivity in deep submicrometre devices differs from the currently produced micrometre size devices, making a revision of the validity of conventional semiconductor manufacturing heuristics for future technology mandatory.<> 相似文献
17.
Metal Organic Framework Crystals in Mixed‐Matrix Membranes: Impact of the Filler Morphology on the Gas Separation Performance 下载免费PDF全文
Anahid Sabetghadam Beatriz Seoane Damla Keskin Nicole Duim Tania Rodenas Salman Shahid Sara Sorribas Clément Le Guillouzer Guillaume Clet Carlos Tellez Marco Daturi Joaquin Coronas Freek Kapteijn Jorge Gascon 《Advanced functional materials》2016,26(18):3154-3163
Mixed‐matrix membranes comprising NH2‐MIL‐53(Al) and Matrimid or 6FDA‐DAM have been investigated. The metal organic framework (MOF) loading has been varied between 5 and 20 wt%, while NH2‐MIL‐53(Al) with three different morphologies, nanoparticles, nanorods, and microneedles has been dispersed in Matrimid. The synthesized membranes have been tested in the separation of CO2 from CH4 in an equimolar mixture. At 3 bar and 298 K for 8 wt% MOF loading, incorporation of NH2‐MIL‐53(Al) nanoparticles leads to the largest improvement compared to nanorods and microneedles. The incorporation of the best performing filler, i.e., NH2‐MIL‐53(Al) nanoparticles, into the highly permeable 6FDA‐DAM has a larger effect, and the CO2 permeability increases up to 85% with slightly lower selectivities for 20 wt% MOF loading. Specifically, these membranes have a permeability of 660 Barrer with a CO2/CH4 separation factor of 28, leading to a performance very close to the Robeson limit of 2008. Furthermore, a new non‐destructive technique based on Raman spectroscopy mapping is introduced to assess the homogeneity of the filler dispersion in the polymer matrix. The MOF contribution can be calculated by modeling the spectra. The determined homogeneity of the MOF filler distribution in the polymer is confirmed by focused ion beam scanning electron microscopy analysis. 相似文献
18.
Sea-air flux of CO2 in the Caribbean Sea estimated using in situ and remote sensing data 总被引:2,自引:0,他引:2
Empirical relationships between sea surface carbon dioxide fugacity (fCO2sw) and sea surface temperature (SST) were applied to datasets of remotely sensed SST to create fCO2sw fields in the Caribbean Sea. SST datasets from different sensors were used, as well as the SST fields created by optimum interpolation of bias corrected AVHRR data. Empirical relationships were derived using shipboard fCO2sw data, in situ SST data, and SST data from the remote sensing platforms. The results show that the application of a relationship based on shipboard SST data, on fields of remotely sensed SST yields biased fCO2sw values. This bias is reduced if the fCO2sw-SST relationships are derived using the same SST data that are used to create the SST fields. The fCO2sw fields found to best reproduce observed fCO2sw are used in combination with wind speed data from QuikSCAT to create weekly maps of the sea-air CO2 flux in the Caribbean Sea in 2002. The region to the SW of Cuba was a source of CO2 to the atmosphere throughout 2002, and the region to the NE was a sink during winter and spring and a source during summer and fall. The net uptake of CO2 in the region was doubled when potential skin layer effects on fCO2sw were taken into account. 相似文献
19.
The open circuit voltage of the electrochemical cell Ag (nano)|solid silver electrolyte|Ag (macro) is found to be inherently unstable. Even under conditions which support the morphological stability of the arrangement of nanocrystalline silver, the particles grow significantly as soon as they function as electrodes; i.e. when they are in contact with a silver electrolyte and connected electronically at the same time. The process is shown to be due to electrochemical Ostwald ripening with the interfacial transfer of Ag+ through the Ag/electrolyte interface being the rate limiting step. Its activation energy is 0.01 eV. The decay is in good agreement with modelling results. 相似文献
20.
The 1H and 13C nuclear magnetic resonance (n.m.r.) spectra of a delayed coking feedstock and products, presented in a previous paper, are analysed here in detail by matching results from inspection of both nuclei. The conventional spectra of whole samples are used in combination with elemental analysis data, and substantial agreement is obtained. Differences are explored to yield valuable information. Interpretation of some band assignments is modified to account for new results. This approach results in a detailed quantitative estimation of a few key structures that contain the main functional groups that characterize these petroleum fractions. 相似文献