953 resultados para Spray coverage


Relevância:

20.00% 20.00%

Publicador:

Resumo:

The purpose of this study was to determine the rela­tive rate of corrosion of iron-tin alloys containing low percentages of tin. Since in the world today, a great deal of work is being done to develop large tin deposits and new methods devised to treat these ores, it is possible that the metal will become abundant and will obtain a more important position in the metal industry.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Electrospinning (ES) can readily produce polymer fibers with cross-sectional dimensions ranging from tens of nanometers to tens of microns. Qualitative estimates of surface area coverage are rather intuitive. However, quantitative analytical and numerical methods for predicting surface coverage during ES have not been covered in sufficient depth to be applied in the design of novel materials, surfaces, and devices from ES fibers. This article presents a modeling approach to ES surface coverage where an analytical model is derived for use in quantitative prediction of surface coverage of ES fibers. The analytical model is used to predict the diameter of circular deposition areas of constant field strength and constant electrostatic force. Experimental results of polyvinyl alcohol fibers are reported and compared to numerical models to supplement the analytical model derived. The analytical model provides scientists and engineers a method for estimating surface area coverage. Both applied voltage and capillary-to-collection-plate separation are treated as independent variables for the analysis. The electric field produced by the ES process was modeled using COMSOL Multiphysics software to determine a correlation between the applied field strength and the size of the deposition area of the ES fibers. MATLAB scripts were utilized to combine the numerical COMSOL results with derived analytical equations. Experimental results reinforce the parametric trends produced via modeling and lend credibility to the use of modeling techniques for the qualitative prediction of surface area coverage from ES. (Copyright: 2014 American Vacuum Society.)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Background Access to health care can be described along four dimensions: geographic accessibility, availability, financial accessibility and acceptability. Geographic accessibility measures how physically accessible resources are for the population, while availability reflects what resources are available and in what amount. Combining these two types of measure into a single index provides a measure of geographic (or spatial) coverage, which is an important measure for assessing the degree of accessibility of a health care network. Results This paper describes the latest version of AccessMod, an extension to the Geographical Information System ArcView 3.×, and provides an example of application of this tool. AccessMod 3 allows one to compute geographic coverage to health care using terrain information and population distribution. Four major types of analysis are available in AccessMod: (1) modeling the coverage of catchment areas linked to an existing health facility network based on travel time, to provide a measure of physical accessibility to health care; (2) modeling geographic coverage according to the availability of services; (3) projecting the coverage of a scaling-up of an existing network; (4) providing information for cost effectiveness analysis when little information about the existing network is available. In addition to integrating travelling time, population distribution and the population coverage capacity specific to each health facility in the network, AccessMod can incorporate the influence of landscape components (e.g. topography, river and road networks, vegetation) that impact travelling time to and from facilities. Topographical constraints can be taken into account through an anisotropic analysis that considers the direction of movement. We provide an example of the application of AccessMod in the southern part of Malawi that shows the influences of the landscape constraints and of the modes of transportation on geographic coverage. Conclusion By incorporating the demand (population) and the supply (capacities of heath care centers), AccessMod provides a unifying tool to efficiently assess the geographic coverage of a network of health care facilities. This tool should be of particular interest to developing countries that have a relatively good geographic information on population distribution, terrain, and health facility locations.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Terrorists, policy-makers, and terrorism scholars have long assumed that the mere threat of terrorist strikes affects societies that have experienced actual acts of terrorism. For this reason, most definitions of terrorism include the threat of violent political acts against civilians. But so far research has neither validated this conventional wisdom nor demonstrated how actual and mass-mediated threat messages by terrorists and terror alerts and threat assessments by government officials affect the public in targeted states. This paper fills the gap providing evidence that who conveys such messages matters and that mass-mediated threat messages by al Qaeda leaders and announced alerts and threat assessments by U.S. administration officials had a significant impact on the American public’s threat perceptions in the post-9/11 years.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

OBJECTIVE To assess the association between socio-demographic factors and the quality of preventive care and chronic care of cardiovascular (CV) risk factors in a country with universal health care coverage. METHODS Our retrospective cohort assessed a random sample of 966 patients aged 50-80years followed over 2years (2005-2006) in 4 Swiss university primary care settings (Basel/Geneva/Lausanne/Zürich). We used RAND's Quality Assessment Tools indicators and examined recommended preventive care among different socio-demographic subgroups. RESULTS Overall patients received 69.6% of recommended preventive care. Preventive care indicators were more likely to be met among men (72.8% vs. 65.4%; p<0.001), younger patients (from 71.0% at 50-59years to 66.7% at 70-80years, p for trend=0.03) and Swiss patients (71.1% vs. 62.7% in forced migrants; p=0.001). This latter difference remained in multivariate analysis adjusted for gender, age, civil status and occupation (OR 0.68; 95% CI 0.54-0.86). Forced migrants had lower scores for physical examination and breast and colon cancer screening (all p≤0.02). No major differences were seen for chronic care of CV risk factors. CONCLUSION Despite universal healthcare coverage, forced migrants receive less preventive care than Swiss patients in university primary care settings. Greater attention should be paid to forced migrants for preventive care.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

BACKGROUND Histologic experimental studies have reported incomplete neointimal healing in overlapping with respect to nonoverlapping segments in drug-eluting stents (DESs), but these observations have not been confirmed in human coronary arteries hitherto. On the contrary, angiographic and optical coherence tomography studies suggest that DES overlap elicits rather an exaggerated than an incomplete neointimal reaction. METHODS Optical coherence tomography studies from 2 randomized trials including sirolimus-eluting, biolimus-eluting, everolimus-eluting, and zotarolimus-eluting stents were analyzed at 9- to 13-month follow-up. Coverage in overlapping segments was compared versus the corresponding nonoverlapping segments of the same stents, using statistical pooled analysis. RESULTS Forty-two overlaps were found in 31 patients: 11 in sirolimus-eluting stents, 3 in biolimus-eluting stents, 17 in everolimus-eluting stents, and 11 in zotarolimus-eluting stents. The risk ratio of incomplete coverage was 2.35 (95% CI 1.86-2.98) in overlapping versus nonoverlapping segments. Thickness of coverage in overlaps was only 85% (95% CI 81%-90%) of the thickness in nonoverlaps. Significant heterogeneity of the effect was observed, especially pronounced in the comparison of thickness of coverage (I(2) = 90.31). CONCLUSIONS The effect of overlapping DES on neointimal inhibition is markedly heterogeneous: on average, DES overlap is associated with more incomplete and thinner coverage, but in some cases, the overlap elicits an exaggerated neointimal reaction, thicker than in the corresponding nonoverlapping segments. These results might help to understand why overlapping DES is associated with worse clinical outcomes, both in terms of thrombotic phenomena and in terms of restenosis and revascularization.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The paper examines the question, in how far Fukushima caused changes in the media coverage and the public opinion about nuclear power in Germany. To answer this question we used two methods, content analysis and survey. Firstly we analysed data from a quantitative content analyses to examine changes in the media coverage about nuclear power between 2010 and 2011. The first investigation period lasted from 10.07.2010 to 04.09.2010, immediately before the German Bundestag vote for the lifetime extension of nuclear power stations. The second investigation period covered the first two months of media coverage after Fukushima from 12.03.2011 to 16.5.2011. Secondly our data consist of a representative telephone panel survey (n=341). As the first wave was carried out from 16.8.2010 to 06.9.2010 and the second wave from 15.5.2011 to 04.06.2011 these data set gives us the unique possibility to investigate attitude changes about nuclear power on the individual level.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Outside lobbying is a key strategy for social movements, interest groups and political parties for mobilising public opinion through the media in order to pressure policymakers and influence the policymaking process. Relying on semi-structured interviews and newspaper content analysis in six Western European countries, this article examines the use of four outside lobbying strategies – media-related activities, informing (about) the public, mobilisation and protest – and the amount of media coverage they attract. While some strategies are systematically less pursued than others, we find variation in their relative share across institutional contexts and actor types. Given that most of these differences are not accurately mirrored in the media, we conclude that media coverage is only loosely connected to outside lobbying behaviour, and that the media respond differently to a given strategy when used by different actors. Thus, the ability of different outside lobbying strategies to generate media coverage critically depends on who makes use of them.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Land use science has traditionally used case-study approaches for in-depth investigation of land use change processes and impacts. Meta-studies synthesize findings across case-study evidence to identify general patterns. In this paper, we provide a review of meta-studies in land use science. Various meta-studies have been conducted, which synthesize deforestation and agricultural land use change processes, while other important changes, such as urbanization, wetland conversion, and grassland dynamics have hardly been addressed. Meta-studies of land use change impacts focus mostly on biodiversity and biogeochemical cycles, while meta-studies of socioeconomic consequences are rare. Land use change processes and land use change impacts are generally addressed in isolation, while only few studies considered trajectories of drivers through changes to their impacts and their potential feedbacks. We provide a conceptual framework for linking meta-studies of land use change processes and impacts for the analysis of coupled human–environmental systems. Moreover, we provide suggestions for combining meta-studies of different land use change processes to develop a more integrated theory of land use change, and for combining meta-studies of land use change impacts to identify tradeoffs between different impacts. Land use science can benefit from an improved conceptualization of land use change processes and their impacts, and from new methods that combine meta-study findings to advance our understanding of human–environmental systems.