18 research outputs found

    Observation of liquid glass in suspensions of ellipsoidal colloids

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    Despite the omnipresence of colloidal suspensions, little is known about the influence of shape on phase transformations, especially in nonequilibrium. To date, real-space imaging results are limited to systems composed of spherical colloids. In most natural and technical systems, however, particles are non-spherical and their structural dynamics are determined by translational and rotational degrees of freedom. Using confocal microscopy, we reveal that suspensions of ellipsoidal colloids form an unexpected state of matter, a liquid glass in which rotations are frozen while translations remain fluid. Image analysis unveils hitherto unknown nematic precursors as characteristic structural elements of this state. The mutual obstruction of these ramified clusters prevents liquid crystalline order. Our results give unique insight into the interplay between local structures and phase transformations. This helps to guide applications such as self-assembly of colloidal superstructures and also gives first evidence of the importance of shape on the glass transition in general.Comment: 19 pages, 6 figures; additional SI; submitte

    Dynamic Human Body Models in Vehicle Safety: An Overview

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    Significant trends in the vehicle industry are autonomous driving, micromobility, electrification and the increased use of shared mobility solutions. These new vehicle automation and mobility classes lead to a larger number of occupant positions, interiors and load directions. As safety systems interact with and protect occupants, it is essential to place the human, with its variability and vulnerability, at the center of the design and operation of these systems. Digital human body models (HBMs) can help meet these requirements and are therefore increasingly being integrated into the development of new vehicle models. This contribution provides an overview of current HBMs and their applications in vehicle safety in different driving modes. The authors briefly introduce the underlying mathematical methods and present a selection of HBMs to the reader. An overview table with guideline values for simulation times, common applications and available variants of the models is provided. To provide insight into the broad application of HBMs, the authors present three case studies in the field of vehicle safety: (i) in-crash finite element simulations and injuries of riders on a motorcycle; (ii) scenario-based assessment of the active pre-crash behavior of occupants with the Madymo multibody HBM; (iii) prediction of human behavior in a take-over scenario using the EMMA model

    Assessing zoo giraffe survivorship: Methodological aspects, historical improvement and a rapid demographic shift

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    Giraffe have been kept in zoos for a long time. They have traditionally been considered difficult to maintain due to various husbandry requirements, including their nature as intrinsic browsers. However, zoo animals are expected to achieve higher survivorship than free-ranging conspecifics due to protection against dangers that would be experienced in their natural habitat. Global zoo giraffe data was analysed for historical developments of juvenile and adult survivorship, assessing the data with various demographic measures and comparing it to that of populations from natural habitats. Additionally, zoo population structure was analysed, in particular with respect to two events that occurred in parallel in 2014—a recommendation to restrict the number of new offspring given by the European Endangered Species Programme (EEP) studbook coordinator and the culling of a designated ‘surplus’ giraffe at Copenhagen Zoo that attracted global media attention. Both juvenile and adult giraffe survivorship has increased over time, suggesting advances in giraffe husbandry. For juveniles, this process has been continuous, whereas for adults the major progress has been in the most recent cohort (from 2000 onwards), in parallel with the publication of various husbandry guidelines. Zoo giraffe survivorship is now generally above that observed in natural habitats. Simple survivorship analyses appear suitable to describe these developments. Since 2014, the global giraffe population has undergone a rapid demographic shift from a growing to an ageing population, indicating a drastic limitation of reproduction rather than a system where reproduction is allowed and selected animals are killed (and possibly fed to carnivores). Thus, giraffe are both a showcase example for the historical progress made in zoo animal husbandry due to efforts of the zoo community and serve as an example to discuss implications of different methods of zoo population management

    Building in Hongkong. Field Excursion of the Department of Civil Engineering of the HTWG Konstanz 2012

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    Hongkong steht als Welthandelsmetropole auch fĂŒr Superlative des Bauens. Dies gilt fĂŒr die in britischer Zeit errichteten Bauten, aber auch fĂŒr die nach der Übergabe an China entstandenen HochhĂ€user und BrĂŒckenbauwerke. Der Exkursionsbericht der FakultĂ€t Bauingenieurwesen der HTWG Konstanz gibt einen Eindruck von diesen AktivitĂ€ten. Er schildert BrĂŒcken- und Hochhausbauten, Tunnelbaustellen und die Baustelle eines KlĂ€rschlammverbrennungswerks, die wĂ€hrend einer Exkursionswoche im September 2012 besichtigt wurden. DarĂŒber hinaus gibt er einen Einblick in die wirtschaftliche Dynamik der Stadt.As a global metropolis Hongkong also stands for outstanding building activities. The report depicts the impressions during a student field excursion of the Faculty of Civil Engineering of the University of Applied Sciences Konstanz, Germany, to construction sites in Hongkong in September 2012

    The reference site collaborative network of the european innovation partnership on active and healthy ageing

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    Seventy four Reference Sites of the European Innovation Partnership on Active and Healthy Ageing (EIP on AHA) have been recognised by the European Commission in 2016 for their commitment to excellence in investing and scaling up innovative solutions for active and healthy ageing. The Reference Site Collaborative Network (RSCN) brings together the EIP on AHA Reference Sites awarded by the European Commission, and Candidate Reference Sites into a single forum. The overarching goals are to promote cooperation, share and transfer good practice and solutions in the development and scaling up of health and care strategies, policies and service delivery models, while at the same time supporting the action groups in their work. The RSCN aspires to be recognized by the EU Commission as the principal forum and authority representing all EIP on AHA Reference Sites. The RSCN will contribute to achieve the goals of the EIP on AHA by improving health and care outcomes for citizens across Europe, and the development of sustainable economic growth and the creation of jobs

    Glasdynamik ellipsoider Kolloide

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    Suspensionen von Kolloiden sind etablierte Modellsysteme um das Phasenverhalten, die Struktur und die Dynamik von Materie zu verstehen. Insbesondere anisotrope Partikel zeigen ein komplexes Phasenverhalten, da neben der fluiden und kristallinen Phase weitere Phasen gebildet werden können wie beispielsweise eine nematische Phase. Ellipsoide Kolloide wurden in der Vergangenheit intensiv durch Computersimulationen und im Rahmen theoretischer Arbeiten untersucht, jedoch gibt es bis heute nur sehr wenige experimentelle Erkenntnisse. In dieser Arbeit werden ellipsoide Kern-Schale-Partikel mittels eines thermomechanischen Streckverfahrens prĂ€pariert. Mit den gewonnenen Partikeln werden Proben erstellt, die es erlauben ein Kolloidsystem mit ellipsoiden Partikeln mittels Konfokalmikroskopie dreidimensional, ohne Wirkung externer KrĂ€fte, zu untersuchen. Dazu werden ein Algorithmus zur Bildverarbeitung sowie ein Algorithmus zum Tracking der Partikel entwickelt, die es ermöglichen, die Struktur und die Dynamik des Systems quantitativ zu erfassen. Mit diesen Methoden können erste experimentelle Erkenntnisse zum Phasenverhalten ellipsoider Kolloide in einem dreidimensionalen System gewonnen werden. So zeigt sich abhĂ€ngig von AspektverhĂ€ltnis und Volumenbruch eine fluide oder nematische Phase. Weitere ausfĂŒhrliche Messungen zur Dynamik an einem System von Ellipsoiden mit AspektverhĂ€ltnis a/b=3,5 zeigen das Auftreten von zwei unterschiedlichen GlasĂŒbergĂ€ngen fĂŒr die Translations- und Rotationsdynamik. Damit ergibt sich zwischen diesen beiden ÜbergĂ€ngen ein Zustand, der als FlĂŒssigglas bezeichnet wird. Im Unterschied zu einem FlĂŒssigkristall ist jedoch keine globale nematische Ordnung gegeben. Dieser Zustand wird damit zum ersten Mal in einem dreidimensionalen System nachgewiesen.publishe

    Die endoskopische Biopsie und Resektion von Orbitatumoren

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    Application of the #Enzian classification for endometriosis on MRI: prospective evaluation of inter- and intraobserver agreement

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    Objectives: The purpose of this investigation was to evaluate the inter- and intraobserver variability of the updated #Enzian classification of endometriosis on MRI and to evaluate the influence of reader experience on interobserver concordance. Methods: This was a prospective single-center study. All patients were included who received an MRI of the pelvis for evaluation of endometriosis between March and July 2023 and who have provided written informed consent. Images were reviewed independently for endometriosis by three radiologists, utilizing the MRI-applicable categories of the #Enzian classification. Two radiologists had experience in pelvic MRI and endometriosis imaging. One radiologist had no specific experience in pelvic MRI and received a one-hour briefing beforehand. Results: Fifty consecutive patients (mean age, 34.9 years ±8.6 [standard deviation]) were prospectively evaluated. Interobserver agreement was excellent for diagnosis of deep infiltrating endometriosis (Fleiss’ kappa: 0.89; 95% CI 0.73–1.00; p < 0.001) and endometriomas (Fleiss’ kappa: 0.93; 95% CI 0.77–1.00; p < 0.001). For the experienced readers, interobserver agreement in the assessment of compartments A, B and C was excellent (Îșw ranging from 0.84; 95% CI 0.71–0.97; p < 0.001 to 0.89; 95% CI 0.82–0.97; p < 0.001). For the pairings of the experienced readers to the reader without specific experience in pelvic MRI, agreement was substantial to excellent (Îșw ranging from 0.64; 95% CI 0.44–0.85; p < 0.001 to 0.91; 95% CI 0.84–0.98; p < 0.001). Intraobserver variability was excellent for compartments A, B and C (Îșw ranging from 0.85; 95% CI 0.73–0.96; p < 0.001 to 0.95; 95% CI 0.89–1.00; p < 0.001). Conclusion: With sufficient experience, the #Enzian classification enables the achievement of excellent inter- and intraobserver agreement in MRI-based diagnosis of deep infiltrating endometriosis and endometriomas
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