4,927 research outputs found

    SCHISTOSOMIASIS: GEOSPATIAL SURVEILLANCE AND RESPONSE SYSTEMS IN SOUTHEAST ASIA

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    Geographic information system (GIS) and remote sensing (RS) from Earth-observing satellites offer opportunities for rapid assessment of areas endemic for vector-borne diseases including estimates of populations at risk and guidance to intervention strategies. This presentation deals with GIS and RS applications for the control of schistosomiasis in China and the Philippines. It includes large-scale risk mapping including identification of suitable habitats for Oncomelania hupensis, the intermediate host snail of Schistosoma japonicum. Predictions of infection risk are discussed with reference to ecological transformations and the potential impact of climate change and the potential for long-term temperature increases in the North as well as the impact on rivers, lakes and water resource developments. Potential integration of geospatial mapping and modeling in schistosomiasis surveillance and response systems in Asia within Global Earth Observation System of Systems (GEOSS) guidelines in the health societal benefit area is discussed

    A Technical and Systems Analysis of Hydrogen Fuel in Renewable Energy Systems

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    Within the next century, we must tackle the dual challenges of continuing to meet the increasing global demand for energy services while stabilizing global temperatures to mitigate the effects of anthropogenic climate change. Doing so will require a major restructuring of all energy services on a global scale. Here, we contribute to the understanding of the role of hydrogen fuel in net-zero emissions systems from both a technical and systems perspective. From the technical perspective, we evaluate the activation mechanism of an electrodeposited cobalt selenide hydrogen evolution reaction (HER) catalyst using operando Raman spectroscopy. During this activation process these films, which originally show no catalytic activity toward HER, undergo a compositional change in which selenium in the form of loose, polymeric chains is electrochemically reduced from the material. This work provides a facile method towards investigating catalytic materials under operando conditions, elucidates the changes that occur in this cobalt selenide material during the activation step, and offers potential paths toward the improvement of the cobalt selenide catalyst. At the systems level, we use hourly weather data over multiple decades and historical electricity demand data to analyze the gaps between wind and solar supply and electricity demand for California (CA) and the Western Interconnect (WECC). We quantify the occurrence of resource droughts when the daily power from each resource was less than half of the 39-year daily mean for that day of the year. Using a macro-scale electricity model, we then evaluate the potential for both long-term storage (in the form of power-to-gas-to-power) and more geographically diverse generation resources to minimize system costs. For wind-solar-battery electricity systems, meeting California demand with WECC generation resources reduces the cost by 9% compared to constraining resources entirely to California. Adding long-duration storage lowers system costs by 21% when treating California as an island. This data-driven analysis quantifies rare weather-related events and provides an understanding that can be used to inform stakeholders in future electricity systems.</p

    Percolation of Partially Interdependent Scale-free Networks

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    We study the percolation behavior of two interdependent scale-free (SF) networks under random failure of 1-pp fraction of nodes. Our results are based on numerical solutions of analytical expressions and simulations. We find that as the coupling strength between the two networks qq reduces from 1 (fully coupled) to 0 (no coupling), there exist two critical coupling strengths q1q_1 and q2q_2, which separate three different regions with different behavior of the giant component as a function of pp. (i) For q≥q1q \geq q_1, an abrupt collapse transition occurs at p=pcp=p_c. (ii) For q2<q<q1q_2<q<q_1, the giant component has a hybrid transition combined of both, abrupt decrease at a certain p=pcjumpp=p^{jump}_c followed by a smooth decrease to zero for p<pcjumpp < p^{jump}_c as pp decreases to zero. (iii) For q≤q2q \leq q_2, the giant component has a continuous second-order transition (at p=pcp=p_c). We find that (a)(a) for λ≤3\lambda \leq 3, q1≡1q_1 \equiv 1; and for λ>3\lambda > 3, q1q_1 decreases with increasing λ\lambda. (b)(b) In the hybrid transition, at the q2<q<q1q_2 < q < q_1 region, the mutual giant component P∞P_{\infty} jumps discontinuously at p=pcjumpp=p^{jump}_c to a very small but non-zero value, and when reducing pp, P∞P_{\infty} continuously approaches to 0 at pc=0p_c = 0 for λ0\lambda 0 for λ>3\lambda > 3. Thus, the known theoretical pc=0p_c=0 for a single network with λ⩽3\lambda \leqslant 3 is expected to be valid also for strictly partial interdependent networks.Comment: 20 pages, 17 figure
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