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Lanthanide(III)-Based Single-Molecule Magnets: Design, Synthesis, Magnetic and Luminescent Properties
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Knowledge infrastructures for societal transformation. What understanding of data do we need in order to integrate digital technologies meaningfully into societal change?
No full textParticle image velocimetry for spray measurement of an Aerosol-on-Demand jet-printhead
No full textAerosol jet printing offers advantages over common inkjet methods for printed electronics, such as finer structures, layer homogeneity, and 3-D substrate printing capabilities. Our institute is developing a patented Aerosol-on-Demand (AoD) jet-printing process. Understanding the aerosol spray’s droplet velocity fields is crucial for this development. We report on the use of the particle image velocimetry method to measure the droplet velocities and to demonstrate the on-demand capability of the AoD printing principle. The nature of the spray with very high velocity gradients on the one hand, and sparse droplet density in some regions on the other hand poses great challenges for PIV resulting in vector replacement rates of approximately 45%. Despite this, the measurements successfully quantified the maximum droplet velocities in excess of 3 ms and demonstrated the on-demand capability, confirming a spray cessation time of approximately 50 ms
Helmholtz Open-Source, Open-Model and Open-Data Software Suite for the Design, Scheduling and Control of Integrated Energy Systems
No full textResearch on energy systems is a multi-disciplinary undertaking requiring expert knowledge, data, models, algorithms and their implementation in the form of software. This document and milestone report presents Open-X solutions from the Helmholtz Energy System Design (ESD) Program – Topic 2 and outlines how they can be used by outlining four exemplary use cases
A 20-year spatio-temporal analysis of 3D radar-based hail tracks in Germany: trends and regional differences
No full textFor a long time, the lack of archived radar data in Germany prevented comprehensive, long-term studies of convective storms. However, the recent availability of a 20-year, homogeneous dataset based on 16, and in some years 17, single-polarization C-band radars now allows for consistent, national-scale analyses. This dataset provides a solid foundation for more precise hail statistical assessments and long-term hail frequency estimation, including potential trends. A tracking algorithm (TRACE3D), which was specifically modified to detect severe convective cells with the potential to produce hail, was used to identify 15,577 potential hail tracks (PHTs) during the summer half-year period from 2005 to 2024. Validation against building insurance data shows that the modified TRACE3D algorithm performs reasonably well and can adequately reproduce hail statistics in Germany. The spatial distribution of the PHTs reveals distinct regional patterns, including a north-to-south gradient influenced by the proximity to seas and orographic features. The highest hail frequency occurs south of Stuttgart and over the Bavarian Prealps. Most tracks are shorter than 40 km and last no more than 75 min (both at the 75th percentile). Nearly 60% of the tracks show a propagation direction from southwest to northeast, which aligns with typical mid-tropospheric conditions favoring convection. Furthermore, half of the days with PHTs are associated with atmospheric blocking regimes, such as Scandinavian, European, or Greenland blocking. Hail events in Germany are unevenly distributed in time. Sixty-three percent of days record no PHTs, and there are only occasional periods of intense hail activity with many tracks per day. While many hail days tend to be isolated (40%), under certain weather conditions, serial clustering of several hail days can form. However, such episodes rarely last more than 2 weeks and are often associated with prolonged blocking. Trend analyses show a high annual variability in PHTs with no clear trend for entire Germany. However, significant regional differences emerge: northern and central Germany show a decreasing tendency in PHT occurrence, whereas southern Germany exhibits a significant increase
Measurements of the inclusive W and Z boson production cross sections and their ratios in proton-proton collisions at =13.6 TeV
No full textMeasurements are presented of the W and Z boson production cross sections in proton-proton collisions at a center-of-mass energy of 13.6 TeV. Data collected in 2022 and corresponding to an integrated luminosity of 5.01 fb with one or two identified muons in the final state are analyzed. The results for the products of total inclusive cross sections and branching fractions for muonic decays of W and Z bosons are 11.93 ± 0.08 (syst) ± 0.17 (lumi) (acceptance) nb for W boson production, 8.86 ± 0.06 (syst) ± 0.12 (lumi) (acceptance) nb for W boson production, and 2.021 ± 0.009 (syst) ± 0.028 (lumi) (acceptance) nb for the Z boson production in the dimuon mass range of 60–120 GeV, all with negligible statistical uncertainties. Furthermore, the corresponding fiducial cross sections, as well as cross section ratios for both fiducial and total phase space, are provided. The ratios include charge-separated results for W boson production (W and W) and the sum of the two contributions (W), each relative to the measured Z boson production cross section. Additionally, the ratio of the measured cross sections for W and W boson production is reported. All measurements are in agreement with theoretical predictions, calculated at next-to-next-to-leading order accuracy in quantum chromodynamics
Trust and the dynamics of network formation
No full textWe evaluate the effect of reciprocal trust within pairs of individuals—gauged by total potential earnings in a trust experiment—on the probability of relationship formation, in comparison with well-known determinants of social ties, such as time of exposure and homophily along demographic traits. We measured trust and trustworthiness for every individual in an incoming cohort of undergraduate students before they began interacting. Using relationship data sourced from surveys and campus entry/exit times between one month and two years after the trust experiment, we find that reciprocal trust is neither a statistically nor an economically significant factor in determining the students’ social networks. Instead, time of exposure, prior acquaintance, and other demographic characteristics play important and persistent roles in relationship formation