ALBERT

Description: The aragonitic skeletons of scleractinian cold-water corals can serve as valuable archives in paleoceanographic studies. The potential of δ88/86Sr, Sr/Ca, Mg/Ca, Li/Ca and Mg/Li ratios of the cold-water coral Lophelia pertusa to record intermediate water mass properties has been investigated. Here we used samples from several locations along the European continental margin spanning a large temperature range from 6 to 14 °C. Stable strontium isotope measurements were carried out with the recently developed double spike TIMS technique and our results differ from those obtained with less precise methods. In contrast to the strong positive relationship with temperature of previous studies, our results suggest that δ88/86Sr measured in scleractinian cold-water corals is not controlled by seawater temperature, but reflects the Sr isotopic composition of seawater with an offset of Δ88/86Sr = − 0.196‰. As found in previous studies, the elemental ratios Sr/Ca, Li/Ca and Mg/Li measured in corals are significantly related to water temperature and do not correlate with salinity. Moreover, Sr/Ca ratios in L. pertusa display the expected inverse correlation with temperature. However, the variance in the Sr/Ca data severely limits the accuracy of paleotemperature estimates. The Li/Ca and Mg/Ca ratios reveal other influences besides temperature such as pH and/or growth or calcification rate. However, corresponding Mg/Li ratios in L. pertusa are more tightly related to temperature as they remove these secondary effects. In particular, the Mg/Li ratio in L. pertusa may serve as a new promising paleotemperature proxy for intermediate water masses. Our dataset represents the most extensive geochemical examination of L. pertusa to date, revealing a temperature sensitivity of 0.015 mol/mmol/°C for Mg/Li. However, using this temperature dependence and the precision of 5.3% (2SD) only temperature variations larger than ~ 1.5 °C can be resolved with 95% confidence.

Description: The major structural characteristics of zooplankton communities that inhabit 35 Arctic lakes in the catchment basin of the Anabar River (Yakutia) have been analyzed. The ecological state of the lakes has been evaluated. The structure-forming abiotic factors that have the greatest influence on the formation of zooplankton communities have been revealed using the indirect ordination method.

Description: This study aims to provide a systematic overview and comparison of capital and O&M costs models for CO2 pipelines and booster stations currently available in literature. Our findings indicate significantly large cost ranges for the results provided by the different cost models. Two main types of capital cost models for pipeline transport were found in literature, models relating diameter to costs and models relating mass flow to costs. For the nine diameter based models examined, a capital cost range is found of, for instance, 0.8–5.5 M€2010/km for a pipeline diameter of 0.8 m and a length of 25 km. For the five mass flow based cost models evaluated in this study, a cost range is found of, for instance, 0.9–2.1 M€2010/km for a mass flow of 750 kg/s over 25 km (TRUNK-25). An important additional factor is that all capital costs models for CO2 pipeline transport, directly or indirectly, depend on the diameter. Therefore, a systematic overview is made of the various equations and parameter used to calculate the diameter. By applying these equations and parameters to a common mass flow, height difference and length result in diameters between 0.59 and 0.91 m for TRUNK-25. The main reason for this range was different assumptions about specific pressure drop and velocity. Combining the range for diameter, mass flow and diameter based cost models gives a capital and levelized cost range which varied by a factor 10 for a given mass flow and length. The levelized cost range will further increase if the discrepancy in O&M costs is added, for which estimations vary between 4.5 and 75 €/m/year for a pipeline diameter of 0.8 m. On top of this, most cost models underestimate the capital costs of CO2 pipelines. Only two cost models (namely the models who relate the costs to the weight of the pipeline) take into account the higher material requirements which are typically required for CO2 pipelines. The other sources use existing onshore natural gas pipelines as the basis for their cost estimations, and thereby underestimating the material costs for CO2 pipelines. Additionally, most cost models are based on relatively old pipelines constructed in the United States in the 1990s and early 2000s and do not consider the large increase in material prices in the last several years. Furthermore, key model characteristics are identified for a general cost comparison of CCS with other technologies and a system analysis over time. For a general cost comparison of CCS with other technologies, pipeline cost models with parameters which have physical or economic meaning are the preferred option. These are easy to interpret and can be adjusted to new conditions. A linear cost model is an example of such an model. For a system analysis over time, it is advised to adapt a pipeline cost model related to the weight of the pipeline, which is the only cost model that specifically models thickness of the pipeline and include material prices, to incorporate the effect of impurities and pipeline technology development. For modeling booster station costs, a relation between capacity and costs including some economies of scale seems to be the most appropriate. However, the cost range found in literature is very large, for instance, 3.1–3.6 M€2010 for a booster station with a capacity of 1.25 MWe. Therefore, validation of the booster station cost is required before such models are applied in further research.

Description: In the past three decades, deductive games have become interesting from the algorithmic point of view. Deductive games are two players zero sum games of imperfect information. The first player, called "codemaker", chooses a secret code and the second player, called "codebreaker", tries to break the secret code by making as few guesses as possible, exploiting information that is given by the codemaker after each guess. A well known deductive game is the famous Mastermind game. In this paper, we consider the so called Black-Peg variant of Mastermind, where the only information concerning a guess is the number of positions in which the guess coincides with the secret code. More precisely, we deal with a special version of the Black-Peg game with n holes and k 〉= n colors where no repetition of colors is allowed. We present a strategy that identifies the secret code in O(n log n) queries. Our algorithm improves the previous result of Ker-I Ko and Shia-Chung Teng (1985) by almost a factor of 2 for the case k = n. To our knowledge there is no previous work dealing with the case k 〉 n. Keywords: Mastermind; combinatorial problems; permutations; algorithms

Description: We present a new quantum-inspired evolutionary algorithm, the attractor population QEA (apQEA). Our benchmark problem is a classical and difficult problem from Combinatorics, namely finding low-discrepancy colorings in the hypergraph of arithmetic progressions on the first n integers, which is a massive hypergraph (e.g., with approx. 3.88 ×1011 hyperedges for n = 250 000). Its optimal low-discrepancy coloring bound is known and it has been a long-standing open problem to give practically and/or theoretically efficient algorithms. We show that apQEA outperforms known QEA approaches and the classical combinatorial algorithm (Sárközy 1974) by a large margin. Regarding practicability, it is also far superior to the SDP-based polynomial-time algorithm of Bansal (2010), the latter being a breakthrough work from a theoretical point of view. Thus we give the first practical algorithm to construct optimal colorings in this hypergraph, up to a constant factor. We hope that our work will spur further applications of Algorithm Engineering to Combinatorics.

Description: ‘Transgovernance: Advancing Sustainability Governance’ analyses what implications recent and ongoing changes in the relations between politics, science and media – together characterized as the emergence of a knowledge democracy – may have for governance for sustainable development, on global and other levels of societal decision making, and vice versa: How can the discussion on sustainable development contribute to a knowledge democracy? How can concepts such as second modernity, reflexivity, configuration theory, (meta)governance theory and cultural theory contribute to a ‘transgovernance’ approach which goes beyond mainstream sustainability governance? This volume presents contributions from various angles: international relations, governance and metagovernance theory, (environmental) economics and innovation science. It offers challenging insights regarding institutions and transformation processes, and into the paradigms behind contemporary sustainability governance. This book gives the sustainability governance debate a new context. It transforms classical questions into new options for societal decision making and identifies starting points and strategies aimed at effective governance of transitions to sustainability.

Description: As attention to adaptation to climate change increases, there is a growing call for adaptation approaches that focus on risk management. There is also greater recognition that the rate and magnitude of climate variability and change may exceed the limits to adaptation of socio-ecological systems. We offer an actor-centered, risk-based definition for adaptation limits in social systems. Specifically, we frame adaptation limits as the point at which an actor's objectives cannot be secured from intolerable risks through adaptive actions. These limits are significant because exceeding a limit will either result in intolerable losses on the affected actor or system, or precipitate a discontinuous (or transformational) change of behavior by actors. Such discontinuities in behavior have implications for the distribution of risks, with potentially significant governance consequences. We further argue that some adaptation limits are dynamic through time. We conclude with recommendations for further research into adaptation limits and challenges to risk governance.

Description: Geophysical data acquired along the Antarctic passive margins constrain the structure and geometry of the deformed continental crust. Crustal thickness estimates range between 7 and 50 km and the Antarctic continent–ocean transition zone (COTZ) extends up to 100–670 km towards the ocean. Continental deformation prior to rifting over a c. 100 million years long time span resulted in crustal stretching factors varying between 1.8 and 5.9. The time span of deformation was sufficiently large and the rifting velocity low enough to extend the margin by up to 300–400 km. Crustal thinning generates a significant subsidence and shallow water passages might already have developed during the rifting phase along the margin. Accounting for accurate continental margin deformation has also consequences for plate-tectonic reconstructions.