Microbial Effects in the Context of Past German Safety Cases (KIT Scientific Reports ; 7744)

This review describes the organic inventory in the wastes in German facilities, the microbial processes, such as aerobic and anaerobic processes, sulfate reduction, pH and ionic strength ranges and chaotropic effects on microbial activity. The microbial effects are discussed for resident and introduced microorganisms and the environmental conditions. The microbial population above the Gorleben salt dome and their effects of microorganisms on the retention of technetium and selenium are shown

Comparison between the in situ and laboratory water retention curves for a silty sand

After an extreme rainfall event in May 2002 a series of landslides occurred in Ruedlingen in Canton Schaffhausen, North Switzerland. A 38° steep slope has been chosen in this area beside the river Rhine to carry out an artificial rainfall experiment to investigate the dependence between rainfall, suction, saturation and shear resistance. Two sprinkling experiments were conducted to represent an extreme rainfall event, the second of which resulted in failure of 130 m 3 of the slope. Several cycles of wetting and drying were applied to the soil and suction and volumetric water content were measured at different depths in three locations of the slope, by which in-situ Water Retention Curves (WRC) can be derived. The WRC of an undisturbed sample was also determined from laboratory test. The in situ and laboratory WRCs are compared in this paper and the differences will be discussed

Mountain Risks: two case histories of landslides induced by artificial rainfall on steep slopes

Mountainous areas tend to be exposed to an enhanced risk of damage caused by natural hazards; most often exacerbated by the topography (leading to gravitational mass movements such as avalanches, landslides, mud and debris flows). This contribution compares landslides induced by artificial rainfall on two different areas located in Switzerland. One field test site was located on slopes above Saas Balen (Gruben glacier, Canton Wallis, Switzerland) and was instrumented. Artificial rainfall tests were carried out in the summers of 1999 and 2000 to investigate hydro-mechanical mechanisms of instability (Teysseire et al., 2000). Shallow failure occurred in the steeper instrumented slope in 2000. The second test field is located near Ruedlingen (Canton Schaffhausen, Switzerland). A landslide triggering experiment was carried out there in autumn 2008 and spring 2009 to replicate the effects of a heavy rainfall event of May 2002, in which 100 mm rain fell in 40 minutes, causing 42 superficial landslides. The slope was subjected to extreme rainfall by artificial means in October 2008 and in March 2009, triggering about 130 m3 of debris. Infiltration of rainfall has led to surface instability slopes in an alpine moraine (Gruben) and in silty sand (Ruedlingen). Both slopes were steeper than the internal angle of friction, having different initial degrees of saturation and suction. The hydromechanical behaviour of these two field full scale landslides will be compared, trying to expose a deeper understanding of the rainfall induced failure mechanisms

An ion trap built with photonic crystal fibre technology

We demonstrate a surface-electrode ion trap fabricated using techniques transferred from the manufacture of photonic-crystal fibres. This provides a relatively straightforward route for realizing traps with an electrode structure on the 100 micron scale with high optical access. We demonstrate the basic functionality of the trap by cooling a single ion to the quantum ground state, allowing us to measure a heating rate from the ground state of 787(24) quanta/s. Variation of the fabrication procedure used here may provide access to traps in this geometry with trap scales between 100 um and 10 um.Comment: 6 pages, 4 figure

Crack initiation and endurance limit of hard steels under multiaxial cyclic loads

The endurance limit and the mechanisms o f fatigue crack initiation in the high cycle regime were investigated using round specimens o f the bearing steel 52100 under longitudinal forces and torsional moments and combinations o f these loads. Three specimen types were examined: smooth specimens and specimens with circumferential notches with radii o f 1.0 and 0.2 mm. The influence ofmean and multiaxial stresses on the endurance limit can be understood by consideration ofcrack initiation mechanisms and micro-mechanics. Crack initiation took place at oxides, carbonitrides and at the surface. The mechanisms ofcrack initiation could be related to the load type: Loads with rotating principal stresses are more damaging fo r nitrides than fo r oxides. Increasing maximum stresses are more dangerous fo r nitrides than fo r oxides, and introduce more damage to the surface than to the nitrides. Normal stresses are more damaging fo r oxides than shear stresses. The endurance limits were calculated by means o f an extended weakest-link model which combines volume and surface crack initiation with related fatigue criteria. For volume crack initiation the criterion o f Dang Van was used. For the correct description o f the competing surface crack initiation, a new criterion was applied. With this concept, a prediction o f the endurance limit is possible fo r loads which produce critical planes and range within a limited regime ofstress ratios.Исследованы предел выносливости и механизмы зарождения усталостных трещин в многоцикловом режиме, используя круглые образцы из подшипниковой стали 52100, подвергаемые действию продольных сил и крутящих моментов, а также комбинации этих нагрузок. Использовали гладкие образцы и образцы с кольцевыми надрезами радиусами 1,0 и 0,2 мм. Влияние средних и многоосных напряжений на предел выносливости может быть объяснено с учетом механизмов зарождения трещин и микромеханики. Зарождение трещин происходило на оксидах, карбонитридах и на поверхности. Механизмы зарождения трещин могут быть связаны с типом нагрузки: нагрузки с вращательными главными напряжениями более деструктивны для нитридов, чем для оксидов. Возрастающие максимальные напряжения более опасны для нитридов, чем для оксидов, и вызывают большие повреждения поверхности, чем нитридов. Нормальные напряжения вызывают большее повреждение оксидов, чем касательные напряжения Пределы выносливости рассчитывали с помощью модифицированной модели слабого звена, которая объединяет зарождение трещин в объеме и на поверхности с соответствующими критериями усталости. Для зарождения трещин в объеме был использован критерий Данг Вана. Для корректного описания конкурирующего зарождения трещин на поверхности был применен новый критерий. С помощью этой концепции можно предсказать предел выносливости для нагрузок, которые создают критические плоскости и диапазон в рамках ограниченного режима коэффициентов асимметрии цикла

Review of the flood risk management system in Germany after the major flood in 2013

Widespread flooding in June 2013 caused damage costs of €6 to 8 billion in Germany, and awoke many memories of the floods in August 2002, which resulted in total damage of €11.6 billion and hence was the most expensive natural hazard event in Germany up to now. The event of 2002 does, however, also mark a reorientation toward an integrated flood risk management system in Germany. Therefore, the flood of 2013 offered the opportunity to review how the measures that politics, administration, and civil society have implemented since 2002 helped to cope with the flood and what still needs to be done to achieve effective and more integrated flood risk management. The review highlights considerable improvements on many levels, in particular (1) an increased consideration of flood hazards in spatial planning and urban development, (2) comprehensive property-level mitigation and preparedness measures, (3) more effective flood warnings and improved coordination of disaster response, and (4) a more targeted maintenance of flood defense systems. In 2013, this led to more effective flood management and to a reduction of damage. Nevertheless, important aspects remain unclear and need to be clarified. This particularly holds for balanced and coordinated strategies for reducing and overcoming the impacts of flooding in large catchments, cross-border and interdisciplinary cooperation, the role of the general public in the different phases of flood risk management, as well as a transparent risk transfer system. Recurring flood events reveal that flood risk management is a continuous task. Hence, risk drivers, such as climate change, land-use changes, economic developments, or demographic change and the resultant risks must be investigated at regular intervals, and risk reduction strategies and processes must be reassessed as well as adapted and implemented in a dialogue with all stakeholders

TensorBank:Tensor Lakehouse for Foundation Model Training

Storing and streaming high dimensional data for foundation model training became a critical requirement with the rise of foundation models beyond natural language. In this paper we introduce TensorBank, a petabyte scale tensor lakehouse capable of streaming tensors from Cloud Object Store (COS) to GPU memory at wire speed based on complex relational queries. We use Hierarchical Statistical Indices (HSI) for query acceleration. Our architecture allows to directly address tensors on block level using HTTP range reads. Once in GPU memory, data can be transformed using PyTorch transforms. We provide a generic PyTorch dataset type with a corresponding dataset factory translating relational queries and requested transformations as an instance. By making use of the HSI, irrelevant blocks can be skipped without reading them as those indices contain statistics on their content at different hierarchical resolution levels. This is an opinionated architecture powered by open standards and making heavy use of open-source technology. Although, hardened for production use using geospatial-temporal data, this architecture generalizes to other use case like computer vision, computational neuroscience, biological sequence analysis and more

The flood of June 2013 in Germany: how much do we know about its impacts?

In June 2013, widespread flooding and consequent damage and losses occurred in Central Europe, especially in Germany. This paper explores what data are available to investigate the adverse impacts of the event, what kind of information can be retrieved from these data and how well data and information fulfil requirements that were recently proposed for disaster reporting on the European and international levels. In accordance with the European Floods Directive (2007/60/EC), impacts on human health, economic activities (and assets), cultural heritage and the environment are described on the national and sub-national scale. Information from governmental reports is complemented by communications on traffic disruptions and surveys of flood-affected residents and companies. Overall, the impacts of the flood event in 2013 were manifold. The study reveals that flood-affected residents suffered from a large range of impacts, among which mental health and supply problems were perceived more seriously than financial losses. The most frequent damage type among affected companies was business interruption. This demonstrates that the current scientific focus on direct (financial) damage is insufficient to describe the overall impacts and severity of flood events. The case further demonstrates that procedures and standards for impact data collection in Germany are widely missing. Present impact data in Germany are fragmentary, heterogeneous, incomplete and difficult to access. In order to fulfil, for example, the monitoring and reporting requirements of the Sendai Framework for Disaster Risk Reduction 2015–2030 that was adopted in March 2015 in Sendai, Japan, more efforts on impact data collection are needed

Ten years of research on synergisms and antagonisms in chemical mixtures: A systematic review and quantitative reappraisal of mixture studies

Background Several reviews of synergisms and antagonisms in chemical mixtures have concluded that synergisms are relatively rare. However, these reviews focused on mixtures composed of specific groups of chemicals, such as pesticides or metals and on toxicity endpoints mostly relevant to ecotoxicology. Doubts remain whether these findings can be generalised. A systematic review not restricted to specific chemical mixtures and including mammalian and human toxicity endpoints is missing. Objectives We conducted a systematic review and quantitative reappraisal of 10 years’ of experimental mixture studies to investigate the frequency and reliability of evaluations of mixture effects as synergistic or antagonistic. Unlike previous reviews, we did not limit our efforts to certain groups of chemicals or specific toxicity outcomes and covered mixture studies relevant to ecotoxicology and human/mammalian toxicology published between 2007 and 2017. Data sources, eligibility criteria We undertook searches for peer-reviewed articles in PubMed, Web of Science, Scopus, GreenFile, ScienceDirect and Toxline and included studies of controlled exposures of environmental chemical pollutants, defined as unintentional exposures leading to unintended effects. Studies with viruses, prions or therapeutic agents were excluded, as were records with missing details on chemicals’ identities, toxicities, doses, or concentrations. Study appraisal and synthesis methods To examine the internal validity of studies we developed a risk-of-bias tool tailored to mixture toxicology. For a subset of 388 entries that claimed synergisms or antagonisms, we conducted a quantitative reappraisal of authors’ evaluations by deriving ratios of predicted and observed effective mixture doses (concentrations). Results Our searches produced an inventory of 1220 mixture experiments which we subjected to subgroup analyses. Approximately two thirds of studies did not incorporate more than 2 components. Most experiments relied on low-cost assays with readily quantifiable endpoints. Important toxicity outcomes of relevance for human risk assessment (e.g. carcinogenicity, genotoxicity, reproductive toxicity, immunotoxicity, neurotoxicity) were rarely addressed. The proportion of studies that declared additivity, synergism or antagonisms was approximately equal (one quarter each); the remaining quarter arrived at different evaluations. About half of the 1220 entries were rated as “definitely” or “probably” low risk of bias. Strikingly, relatively few claims of synergistic or antagonistic effects stood up to scrutiny in terms of deviations from expected additivity that exceed the boundaries of acceptable between-study variability. In most cases, the observed mixture doses were not more than two-fold higher or lower than the predicted additive doses. Twenty percent of the entries (N = 78) reported synergisms in excess of that degree of deviation. Our efforts of pinpointing specific factors that predispose to synergistic interactions confirmed previous concerns about the synergistic potential of combinations of triazine, azole and pyrethroid pesticides at environmentally relevant doses. New evidence of synergisms with endocrine disrupting chemicals and metal compounds such as chromium (VI) and nickel in combination with cadmium has emerged. Conclusions, limitations and implications These specific cases of synergisms apart, our results confirm the utility of default application of the dose (concentration) addition concept for predictive assessments of simultaneous exposures to multiple chemicals. However, this strategy must be complemented by an awareness of the synergistic potential of specific classes of chemicals. Our conclusions only apply to the chemical space captured in published mixture studies which is biased towards relatively well-researched chemicals.European Commission, Directorate-General Joint Research Centre, Service Contract CCR.F.933992.X