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161.
162.
Thermocatalytic low temperature conversion (LTC) is a new method for the disposal of sewage sludge. Using this method, sludge is converted into a residual solid (coal) along with reaction water, oil, and non‐condensable gases. The oil can be used as an energy source and the coal as a substitute for charcoal. To this end, it is important to determine whether there are any easily available contaminants present in the coal generated by the process. Contaminants that can be strongly sorbed by sewage sludge solids are, e. g., pharmaceuticals and disinfectants. As an example the fate of the persistent and strong adsorbing disinfectant benzalkonium chloride (BAC) has been investigated within the LTC process. The sewage sludge was spiked with BAC and then subjected to the LTC process. The resulting coal was extracted and analyzed using LC‐LC/ESI‐MS/MS (ion trap). BAC could not be detected in the LTC coal, although it could be extracted from the spiked sludge before the LTC treatment. It can thus be concluded that the investigated compound is not easily available in the coal, and hence that its use does not present a risk.  相似文献   
163.
This study investigates the atmospheric circulation in transient climate simulations with a coupled atmosphere–ocean general circulation model (GCM) for the mid-Holocene (MH) period 7–4.5 ka BP driven with combinations of orbital, solar and greenhouse gas forcings. The focus is on southern South America. Statistical downscaling models are derived from observational data and applied to the simulations to estimate precipitation in south-eastern Patagonia during the MH. These estimates are compared with lake level estimates for Laguna Potrok Aike (LPA) from sediments. Relative to pre-industrial conditions (i.e. 1550–1850), which show extraordinarily high lake levels, the proxy-based reconstructed lake levels during the MH are lower. The downscaled simulated circulation differences indicate higher LPA precipitation during the MH from March to August, higher annual means, and reduced precipitation from September to February. Thus the reconstructed lower LPA lake levels can not be explained solely by the simulated precipitation changes. Possible reasons for this discrepancy are discussed. Based on proxy data from southern South America hypotheses have also been proposed on the latitudinal position of the southern hemispheric westerlies (SHWs). In agreement with some of these hypotheses our simulations show an increased seasonal cycle of the latitudinal position of the SHWs during the MH, which can be explained by the orbital forcing. The simulations also show stronger SHWs over southern Patagonia during austral summer and weaker SHWs during winter. The downscaling model associates weaker SHWs with increased precipitation in the LPA region. However, this relationship is only moderate, and therefore the downscaling model does not support the assumption of a strong link between mean SHWs and precipitation over south-eastern Patagonia, which is the basis of many proxy-based hypotheses about the SHWs.  相似文献   
164.
Mesophotic reefs, hardgrounds and current-controlled pelagic to hemipelagic carbonates are facies marking carbonate platform drowning successions, irrespective of the factors controlling this evolution. A modern analogue of a carbonate platform in a state of drowning, where these facies occur has not been properly reported on to date. In the present study, the sedimentary environments of the Saya de Malha Bank are characterized using a multi-disciplinary approach including sedimentology, hydroacoustics, seismics and oceanography. The Saya de Malha Bank edifice with a surface of 40 808 km2 is located in the tropical Indian Ocean and lies in a water depth of 8 to 300 m extending from the surrounding more than 2000 m deep ocean floor, with no reef reaching the sea surface. Mesophotic coral and red algal facies co-exist with hemipelagic and bioclastic sands, together with a hardground. Ocean currents and internal waves are identified as major sedimentological controlling factors in the absence of elevated nutrient influx. Many features distributed along the present-day Saya de Malha Bank were described from studies presenting fossil examples of carbonate platform drowning. The results herein can therefore be applied to other drowning examples, in some cases allowing for more accurate interpretation of the stratigraphic record.  相似文献   
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166.
In recent decades, significant changes of Arctic sea ice have taken place. These changes are expected to influence the surface energy balance of the ice-covered Arctic Ocean. To quantify this energy ba...  相似文献   
167.
The successful implementation of the Paris Agreement requires substantial energy policy change on the national level. In national energy policy-making, climate change mitigation goals have to be balanced with arguments on other national energy policy goals, namely limiting cost and increasing energy security. Thus far, very little is known about the relative importance of these goals and how they are related to political partisanship. In order to address this gap, we focus on parliamentary discourse around low-carbon energy futures in Germany over the past three decades and analyze the relative importance of, and partisanship around, energy policy goals. We find that the political discourse revolves around four, rather than three, goals as conventionally assumed; improving the competitiveness of the national energy technology industry is not only an additional energy policy goal, it is also highly important in the political discourse. In general, the relative importance of these goals is rather stable over time and partisanship around them is limited. Yet, a sub-analysis of the discourse on renewable energy technologies reveals a high level of partisanship, albeit decreasing over time. Particularly, the energy industry goal’s importance increases while its partisanship vanishes. We discuss how these findings can inform future energy policy research and provide a potential inroad for more ambitious national energy policies.

Key policy insights

  • In addition to the three classic goals of energy policy (limiting cost, securing access and reducing the environmental burden) we identify a fourth policy goal: strengthening the national energy technology industry

  • Conformity between the three classical energy and the industrial policy goals is a key driver explaining policy change

  • For renewable energy technologies, partisanship around this fourth goal is lower than around other goals and decreases over time as innovation allows these technologies to increasingly correspond to policy-makers’ high-level goals

  • Extant research underestimates the importance of industry policy goals, but overestimates environmental co-benefits of low-carbon energy options

  • Paradigmatic policy change in Germany did not depend on top-down shifts in high-level policy goals but was driven by lower-level technology-specific goals

  相似文献   
168.

Minimization of a stochastic cost function is commonly used for approximate sampling in high-dimensional Bayesian inverse problems with Gaussian prior distributions and multimodal posterior distributions. The density of the samples generated by minimization is not the desired target density, unless the observation operator is linear, but the distribution of samples is useful as a proposal density for importance sampling or for Markov chain Monte Carlo methods. In this paper, we focus on applications to sampling from multimodal posterior distributions in high dimensions. We first show that sampling from multimodal distributions is improved by computing all critical points instead of only minimizers of the objective function. For applications to high-dimensional geoscience inverse problems, we demonstrate an efficient approximate weighting that uses a low-rank Gauss-Newton approximation of the determinant of the Jacobian. The method is applied to two toy problems with known posterior distributions and a Darcy flow problem with multiple modes in the posterior.

  相似文献   
169.
A methodology for the development of fully probabilistic seismic risk assessments on water and sewage networks is presented in this paper together with a case study for the system of Manizales, Colombia. These kinds of assessments require the development of probabilistic seismic hazard analysis, the consideration of local site effects, when relevant, the assembly of databases to identify and characterize the exposed elements and the development and assignment of vulnerability models for each type of component. For the case of Manizales, a high-resolution exposure database has been developed (element by element, segment by segment) based on the information and data provided by the owner and operator of the network, Aguas de Manizales. Losses due to earthquakes are obtained after convoluting the hazard and vulnerability inputs in a fully probabilistic manner, using the state-of-the-art methodologies incorporated in the CAPRA risk assessment module. Several risk metrics such as the loss exceedance curve, the loss exceedance probabilities for different time frames and the average annual loss are obtained for the system as a whole as well as disaggregated by component. In addition, repair rates for the pipelines were also calculated. The risk results obtained in this study have been useful for the company in designing and implementing expansion and maintenance plans that explicitly account for seismic risk mitigation issues, as well as to explore and negotiate financial protection alternatives by means of risk transfer and retention schemes, thus becoming a valuable input in the continuous development of good disaster risk management practices in this city.  相似文献   
170.
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