Doubly stabilized perovskite nanocrystal luminescence downconverters

Halide perovskite nanocrystals (NCs) have emerged as a promising material for applications ranging from light-emitting diodes (LEDs) to solar cells and photodetectors. Still, several issues impede the realization of the nanocrystals' full potential, most notably their susceptibility to degradation from environmental stress. This work demonstrates highly stable perovskite nanocrystals (NCs) with quantum yields as high as 95 % by exploiting a ligand-assisted copolymer nanoreactor-based synthesis. The organic ligands thereby serve a dual function by enhancing the uptake of precursors and passivating the NCs. The polymer micelles and ligands thus form a double protection system, shielding the encapsulated NCs from water-, heat- and UV-light-induced degradation. We demonstrate the optoelectronic integrability by incorporating the perovskite NCs as spectrally pure downconverters on top of a deep-blue-emitting organic LED. These results establish a way of stabilizing perovskite NCs for optoelectronics while retaining their excellent optical properties

ISLES 2022: A multi-center magnetic resonance imaging stroke lesion segmentation dataset.

Magnetic resonance imaging (MRI) is an important imaging modality in stroke. Computer based automated medical image processing is increasingly finding its way into clinical routine. The Ischemic Stroke Lesion Segmentation (ISLES) challenge is a continuous effort to develop and identify benchmark methods for acute and sub-acute ischemic stroke lesion segmentation. Here we introduce an expert-annotated, multicenter MRI dataset for segmentation of acute to subacute stroke lesions ( https://doi.org/10.5281/zenodo.7153326 ). This dataset comprises 400 multi-vendor MRI cases with high variability in stroke lesion size, quantity and location. It is split into a training dataset of n = 250 and a test dataset of n = 150. All training data is publicly available. The test dataset will be used for model validation only and will not be released to the public. This dataset serves as the foundation of the ISLES 2022 challenge ( https://www.isles-challenge.org/ ) with the goal of finding algorithmic methods to enable the development and benchmarking of automatic, robust and accurate segmentation methods for ischemic stroke

ISLES 2022: A multi-center magnetic resonance imaging stroke lesion segmentation dataset

Magnetic resonance imaging (MRI) is an important imaging modality in stroke. Computer based automated medical image processing is increasingly finding its way into clinical routine. The Ischemic Stroke Lesion Segmentation (ISLES) challenge is a continuous effort to develop and identify benchmark methods for acute and sub-acute ischemic stroke lesion segmentation. Here we introduce an expert-annotated, multicenter MRI dataset for segmentation of acute to subacute stroke lesions (https://doi.org/10.5281/zenodo.7153326). This dataset comprises 400 multi-vendor MRI cases with high variability in stroke lesion size, quantity and location. It is split into a training dataset of n = 250 and a test dataset of n = 150. All training data is publicly available. The test dataset will be used for model validation only and will not be released to the public. This dataset serves as the foundation of the ISLES 2022 challenge (https://www.isles-challenge.org/) with the goal of finding algorithmic methods to enable the development and benchmarking of automatic, robust and accurate segmentation methods for ischemic stroke

Analyse verbreiteter Anwendungen zum Lesen von elektronischen Büchern

Der Marktanteil elektronischer Bucher (E-Books) am Buchmarkt wächst beständig. Um E-Books zu rezipieren, benötigt man spezielle Leseumgebungen, die als Software (im Browser oder als eigene Anwendung) oder als Spezialgerät (E-Reader) realisiert sein können. Diese Leseumgebungen sind geeignet, Daten über das Leseverhalten zu sammeln. Im Rahmen einer universitären Lehrveranstaltung wurden die Software-Leseumgebungen der beiden deutschen Marktführer Kindle und Tolino untersucht. Der vorliegende Bericht fasst die Ergebnisse dieser Analysen zusammen. Das Ergebnis ist eine umfassende Bestandsaufnahme der digitalen Spuren, die durch die Benutzung der Programme entstehen. Betrachtet wurden die zum Untersuchungszeitpunkt aktuellen Versionen der jeweiligen Webanwendungen und Android-Apps sowie des Kindle-Windows-Clients. Die Ergebnisse entstanden im Rahmen einer Übung zur Vorlesung Fortgeschrittene forensische Informatik II im Wintersemester 2018/19 an der Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), die gemeinsam durchgeführt wurde vom Lehrstuhl fur Informatik 1 und dem Institut für Buchwissenschaft an der FAU

CerAMfacturing, Development of ceramic and multi material components by additive manufacturing methods for personalized medical products, H2020

The cerAMfacturing project will develop a completely new approach for ceramic multi material additive manufacturing which will allow series production of customised and multifunctional components for manifold applications for obtaining property combinations, like electrical conductive/electrical insulating, dense/porous or two-colored components. In five case studies demonstrators for personalized medical products – micro surgical tools, implants, and remedies – such as consumer products will be manufactured starting with the patient specific physical dimensions and ending with components validated under practically relevant conditions. For achieving these goals manifold tasks will be solved starting with method and device development. Especially suspension based additive manufacturing methods will be developed and qualified in cerAMfacturing, because this route promises a much better component performance in comparison to powder based methods. Multi material applications play a dominant role in the project. Beside ceramic/ceramic also ceramic/metal material combinations will be developed. For that purpose either additive manufacturing methods will be qualified or AM methods will be combined with conventional shaping routes like tape casting or ceramic injection moulding. The last mentioned combination of technologies will allow the individualisation of large series production components. Appropriate control methodologies to guarantee a high quality level of the custom made products will be implemented. The cerAMfacturing project will provide the technical equipment for combining AM steps with conventional ceramic shaping routes

Umformbare keramische und/oder pulvermetallurgische Grünfolien und Verfahren zur Umformung dieser keramischen und/oder pulvermetallurgischen Grünfolien

Die Erfindung bezieht sich auf die Gebiete der Keramik und Umformtechnik und betrifft umformbare keramische und/oder pulvermetallurgische Grünfolien, wie sie beispielsweise als Substrate oder Gehäuse für mikroelektronische Bauteile, eingesetzt werden können, und ein Verfahren zur Umformung derartiger Grünfolien.Die Aufgabe der vorliegenden Erfindung besteht in der Angabe von umformbaren keramischen und/oder pulvermetallurgischen Grünfolien, die einen hohen plastischen Umformgrad bei der Umformung mit geringer Umverteilung der Partikel und geringer Abnahme der Packungsdichte realisieren und in der Angabe eines einfachen und sehr kostengünstigen Verfahrens zur Umformung derartiger Grünfolien.Die Aufgabe wird gelöst durch erfindungsgemäße umformbare keramische und/oder pulvermetallurgische Grünfolien, die mindestens keramische und/oder pulvermetallurgische Partikel und ein Bindemittelsystem zur Folienherstellung enthalten, wobei ein lösungsmittellöslicher Bestandteil des Bindemittelsystems und/oder eine zusätzliche lösungsmittellösliche Komponente mit einer gegenüber allen anderen Bestandteilen des Bindemittelsystems höheren Löslichkeit in einem Lösungsmittel vorhanden sind

Microstructure and Interface Characteristics of 17-4PH/YSZ Components after Co-Sintering and Hydrothermal Corrosion

Combining stainless steel with zirconia components by powder technological shaping routes for manufacturing of multifunctional parts is an advantageous and promising one-step method making expensive and time-consuming additional joining steps redundant. However, several requirements for co-shaping and co-sintering of the very different compound partners have to be met. The microstructural and chemical constitution of the interface between both materials plays an important role for the mechanical properties, durability and corrosion resistance of the manufactured parts. In the present study, different shaping techniques for co-shaping of stainless steel and zirconia are introduced. The microstructure and the interphase properties of metal/ceramic hybrid parts have been investigated for samples made by tape casting, subsequent lamination and co-sintering. Nevertheless, the results of this study are valid for components made by other hybrid shaping processes as well. The interfaces were characterized by TEM, FESEM, EDX, and X-ray diffraction. Furthermore, the hydrothermal stability of the material compound was investigated

Co-Sintering behaviour of zirconia-ferritic steel composites

The combination of metallic and ceramic materials allows the combination of positive properties of both and can be applied in various industrial fields. At the moment, the deployment of these composites faces difficult and complex manufacturing. One attempt, which offers a short process route and a high degree of flexibility regarding design is a combined shaping (co-shaping) with a combined sintering (co-sintering). The article will show co-sintering results of different metal-ceramic symmetric and asymmetric multi-layered tapes, consisting of yttria stabilized zirconia combined with a ferritic iron chromium steel. Focus is on the densification and co-sintering behaviour of ceramic layers depending on the sintering behaviour of metallic layers. Co-sintered composites were characterized by field emission scanning electron microscopy, x-ray diffraction measurements and in terms of adhesive tensile strength

Combination of Tape Casting and Paper Technology for Producing Ceramic-Metal Composites and Their further Processing

The combination of materials and manufacturing methods opens up new fields of application. Among the consideration of material-specific properties, selected material combinations can be manufactured. An example is a combination of a stainless steel and a partially-stabilized zirconia as starting powders and subsequent processing into multilayer green films by means of a combination of tape casting and paper technology. These multilayer green sheets are converted into their final state in a co-thermal treatment. Applications in the field of medical technology, water purification or energy conversion open up a broad product portfolio. The following survey provides a brief overview of further application possibilities

Properties of Additive Manufactured Hardmetal Components produced by Fused Filament Fabrication (FFF)

Additive Manufacturing (AM) is experiencing an upswing in many sectors of industry for a broad variety of materials. Processes are mainly developed for polymers and metals. For ceramics and especially hardmetals there are only a few additive processes suitable to produce dense and defect free parts. Fused Filament Fabrication (FFF) is one of the suitable processes, which can be used for the fabrication of hardmetal parts via printing of green parts and consequent sintering. Within this study FFF of different hardmetal compositions representing different Co binder contents and different WC grain sizes are investigated. Main points of this investigation are the adjustment of debindering using different thermal and non-thermal steps and the adjustment of sintering regime. It is shown that FFF is a suitable AM technique for production of hardmetal parts with different compositions and microstructures. Dense parts with magnetic and mechanical properties as conventional produced hardmetals can be achieved. It is shown that with the Fused Filament Fabrication fully dense and defect free hardmetals parts can be produced. Because of the thermoplastic processability of the filaments which can be highly filled with particles this technique is interesting for manufacturing hardmetal parts