The energy hub concept and modeling methodology are widely employed tools for solving resource conversion and storage scheduling problems. For instance, industrial clusters might benefit from determining the suitable time to operate their facilities and to sell electricity to the public power grid, according to legal, economic or environmental factors. In this paper, novel elements are introduced in order to more accurately represent real plants and to reduce the amount of decision variables. The major innovation is to consider devices consuming a resource which is not related to the quantity of output produced, by attaching binary decision variables to certain energy hub outputs. Secondly, a path vector is defined to take into account the flows of resources within the system instead of employing a variable for each branch between the components. The third innovation consists of an additional vector to express the amount of output resources sold from the energy hub, including constraints for those resources which are exported and imported through the same medium. An extended energy hub model is first proposed and then applied to a real plant example, including multiple and heterogeneous resources and performing a comparison between days with different demands, weather conditions and electricity prices. The results obtained in the selected scenarios demonstrate a logical operation scheduling, and therefore validate the proposed approach.
This chapter presents the case of Mexico, which reveals the fact that district/provincial expenditures in health care are inversely related to need, a case in point of the “inverse care law.” Mexico is a middle-income country facing a double burden of infectious and chronic disease and engaged in health sector reform and decentralization. Using the marginality index developed by the Mexican government, the chapter employs a policy-relevant mechanism for highlighting disparity and mapping the intersection of marginality, membership in an indigenous group, and rural poverty. It outlines the implications of the analyses for resource allocation to meet the differential needs for health care more equitably in marginalized areas.
The movement of soil particles by the wind can be measured using wind tunnels and collectors, or dust traps. We tested both in Southeast Spain in order to compare movement in four types of soil. Our tests were carried out in a well-tilled orchard on an Anthrosol, an unploughed Leptosol and Arenosol, and finally on an olive-cropped Cambisol. We estimated soil loss using a wind tunnel with a built-in laser-scanner, and then compared the results with records from nine vaned masts, each with four big spring number eight collectors at different heights, and the same for another nine masts but with a new type of dust trap known as the multidirectional. The collectors can differentiate between overall loss and particle deposition, which is not detectable on a larger scale in the tunnel. The results from the big spring number eight traps and our wind tunnel showed a high degree of correlation (R² = 0.933) and an even closer correlation with the multidirectional trap (R² = 0.978). Moreover, the new multidirectional trap collectors are very efficient and easy to manufacture from thermoplastic filaments with an industrial 3D printer.K e y w o r d s: dust collector, semi-arid environment, tilled soil, unploughed soil, wind tunnel
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.