Atmospheric ice nuclei in the Eyjafjallajökull volcanic ash plume

We have sampled atmospheric ice nuclei (IN) and aerosol in Germany and in Israel during spring 2010. IN were analyzed by the static vapor diffusion chamber FRIDGE, as well as by electron microscopy. During the Eyjafjallajökull volcanic eruption of April 2010 we have measured the highest ice nucleus number concentrations (>600 l−1) in our record of 2 yr of daily IN measurements in central Germany. Even in Israel, located about 5000 km away from Iceland, IN were as high as otherwise only during desert dust storms. The fraction of aerosol activated as ice nuclei at −18 °C and 119% rhice and the corresponding area density of ice-active sites per aerosol surface were considerably higher than what we observed during an intense outbreak of Saharan dust over Europe in May 2008. Pure volcanic ash accounts for at least 53–68% of the 239 individual ice nucleating particles that we collected in aerosol samples from the event and analyzed by electron microscopy. Volcanic ash samples that had been collected close to the eruption site were aerosolized in the laboratory and measured by FRIDGE. Our analysis confirms the relatively poor ice nucleating efficiency (at −18 °C and 119% ice-saturation) of such "fresh" volcanic ash, as it had recently been found by other workers. We find that both the fraction of the aerosol that is active as ice nuclei as well as the density of ice-active sites on the aerosol surface are three orders of magnitude larger in the samples collected from ambient air during the volcanic peaks than in the aerosolized samples from the ash collected close to the eruption site. From this we conclude that the ice-nucleating properties of volcanic ash may be altered substantially by aging and processing during long-range transport in the atmosphere, and that global volcanism deserves further attention as a potential source of atmospheric ice nuclei

Saharan dust and ice nuclei over Central Europe

Surface measurements of aerosol and ice nuclei (IN) at a Central European mountain site during an episode of dust transport from the Sahara are presented. Ice nuclei were sampled by electrostatic precipitation on silicon wafers and were analyzed in an isothermal static vapor diffusion chamber. The transport of mineral dust is simulated by the Eulerian regional dust model DREAM. Ice nuclei and mineral dust are significantly correlated, in particular IN number concentration and aerosol surface area. The ice nucleating characteristics of the aerosol as analyzed with respect to temperature and supersaturation are similar during the dust episode than during the course of the year. This suggests that dust may be a main constituent of ice nucleating aerosols in Central Europe

Siedlungswasserwirtschaft im Zeitalter der Digitalisierung: Cybersicherheit als Achillesferse

Die Digitalisierung in der Siedlungswasserwirtschaft kann dazu beitragen, die Aufgaben, die sich für Wasserversorgung und Abwasserbeseitigung aufgrund des demografischen und klimatischen Wandels ergeben, besser anzugehen. Gleichzeitig können sich durch Cyberangriffe die Risiken für einen Ausfall dieser Kritischen Infrastrukturen vergrößern. Aspekte der Cybersicherheit werden im Wassersektor jedoch noch nicht hinreichend berücksichtigt. Entsprechende Regularien und Maßnahmen zielen alleine auf die Ausfallsicherheit der Infrastrukturen ab und vernachlässigen dabei die Versorgungssicherheit der Bevölkerung. Die Aufmerksamkeit der Politik auf große Wasserunternehmen und Versorgungsgebiete ignoriert Sicherheitslücken bei kleinen und mittleren Betrieben. Kooperationen zwischen mehreren Wasserunternehmen könnten ein geeignetes Mittel sein, diesbezüglich Synergieeffekte zu erzeugen.Digitalization in urban water management can help to better address the challenges for water supply and sanitation due to demographic and climate change. At the same time, cyberattacks can increase the risks for a failure of these critical infrastructures. However, aspects of cybersecurity are not yet sufficiently addressed in the water sector. Corresponding regulations and measures solely aim at the reliability of the infrastructures and neglect the security of supply for the population. Policy attention to large water utilities and supply areas ignores security gaps in small and medium-sized enterprises. Cooperations between several water utilities could be a suitable means of generating synergy effects in this respect

Bolder is better : raising user awareness through salient and concise privacy notices

This paper addresses the question whether the recently proposed approach of concise privacy notices in apps and on websites is effective in raising user awareness. To assess the effectiveness in a realistic setting, we included concise notices in a fictitious but realistic fitness tracking app and asked participants recruited from an online panel to provide their feedback on the usability of the app as a cover story. Importantly, after giving feedback, users were also asked to recall the data practices described in the notices. The experimental setup included the variation of different levels of saliency and riskiness of the privacy notices. Based on a total sample of 2,274 participants, our findings indicate that concise privacy notices are indeed a promising approach to raise user awareness for privacy information when displayed in a salient way, especially in case the notices describe risky data practices. Our results may be helpful for regulators, user advocates and transparency-oriented companies in creating or enforcing better privacy transparency towards average users that do not read traditional privacy policies

QButterfly : lightweight survey extension for online user interaction studies for non-tech-savvy researchers

We provide a user-friendly, flexible, and lightweight open-source HCI toolkit (github.com/QButterfly) that allows non-tech-savvy researchers to conduct online user interaction studies using the widespread Qualtrics and LimeSurvey platforms. These platforms already provide rich functionality (e.g., for experiments or usability tests) and therefore lend themselves to an extension to display stimulus web pages and record clickstreams. The toolkit consists of a survey template with embedded JavaScript, a JavaScript library embedded in the HTML web pages, and scripts to analyze the collected data. No special programming skills are required to set up a study or match survey data and user interaction data after data collection. We empirically validated the software in a laboratory and a field study. We conclude that this extension, even in its preliminary version, has the potential to make online user interaction studies (e.g., with crowdsourced participants) accessible to a broader range of researchers

Keeping Flows Separate: Good Management Practices in Novel Urban Water Systems Derived from Error Analyses

This article examines the causes and addresses the prevention of unintended interconnections, particularly cross-connections, in novel urban water systems using the example of Qingdao, where a Resource Recovery Centre for the reuse of greywater and blackwater has been established for 12,000 inhabitants. With respect to cross-connections, this work incorporated both social-scientific and technical error analyses. The social-scientific error analysis systematically focused on the planning, implementation, and operational phases of the project. Organisational shortcomings were identified in four areas: (A) Coordination and consensus between the commissioned design institutes, (B) information in tenders, expertise, and awareness, (C) ownership by investors, and (D) time management. Based on empirical evidence, this article derives and discusses (eight) recommendations for good management, integrating technical and organisational measures aimed at preventing cross-connections. The pursuit of such measures is appropriate in order to prevent most types of misconnections — not just for the case under discussion, but for other novel urban water systems as well

High-Throughput Techniques for Measuring the Spin Hall Effect

The spin Hall effect in heavy-metal thin films is routinely used to convert charge currents into transverse spin currents and can be used to exert torque on adjacent ferromagnets. Conversely, the inverse spin Hall effect is frequently used to detect spin currents by charge currents in spintronic devices up to the terahertz frequency range. Numerous techniques to measure the spin Hall effect or its inverse have been introduced, most of which require extensive sample preparation by multistep lithography. To enable rapid screening of materials in terms of charge-to-spin conversion, suitable high-throughput methods for measuring the spin Hall angle are required. Here we compare two lithography-free techniques, terahertz emission spectroscopy and broadband ferromagnetic resonance, with standard harmonic Hall measurements and theoretical predictions using the binary-alloy series AuxPt1−x as a benchmark system. Despite their being highly complementary, we find that all three techniques yield a spin Hall angle with approximately the same x dependence, which is also consistent with first-principles calculations. Quantitative discrepancies are discussed in terms of magnetization orientation and interfacial spin-memory loss