1,160 research outputs found
Recommended from our members
Development of high-permittivity glasses for microwave LTCC tapes
One of today's leading packaging concepts in microelectronics and microsystems is the technology of Low Temperature Cofiring Ceramics (LTCC). It is based on ceramic tapes that sinter at low temperatures (< 950 °C) and are capable of fine-line wiring by use of high-conductivity metals, preferably silver ( Ïm = 961 °C).
To lower sintering temperatures of crystalline powders, glass powder is added. Depending on the amount of glass added, two mechanisms of sintering are possible: reactive or nonreactive liquid phase sintering. Reactive sintering requires small amounts (< 10 vol.%) of a very low softening glass (Ïsoft < 400°C). If the glass amount is increased to more than 50 vol.%, nonreactive sintering occurs in the glass softening range. According to the microstructure observed for each case, the respective types of materials are called Glass Bonded Ceramics (GBC) and Glass Ceramic Composites (GCC).
Integration of microwave filters in LTCC multilayers requires inner dielectric layers with medium, temperature-stable permittivities (Δr = 30 to 60) and low dielectric loss (tan ÎŽ < 2 â 10^-3). Up to now, appropriate materials have been realized only by GBC sintering at 900 °C and above. Hence, pure silver metallization is not possible. To overcome this limitation, GCC are a promising way. Therefore, crystalline substances possessing Δr of about 100 and low dielectric loss - for example Ba(La, Nd)2Ti4O12 - were combined with special high-permittivity glasses. Î development of such glasses is presented in this work. Addition of oxides of easily polarizable elements (e. g. Nb2O5, La2O3 , TiO2 ) effects an increase in permittivity of selected basis compositions from the systems BaO-Al2O3-B2O3-SiO2 (Δr up to 15) and La2O3-Ba2O3-TiO2 (Δr up to 20). GCC mixtures made of 65 vol.% of these glasses and 35 vol.% BaLa2Ti4O12 showing microwave properties and sintering temperatures below 900 °C are introduced
Anforderungsanalyse und -definition: Literaturwissenschaftliches und didaktisches Nutzungskonzept, GUI-Konzept, Such- und Findbarkeitskonzept
Das vorliegende Dokument enthÀlt die Anforderungsanalyse und -definition, das literaturwissenschaftliche
und didaktisches Nutzungskonzept, sowie ein GUI-Konzept und ein Such- und Findbarkeitskonzept fĂŒr die im Rahmen des Projekts "GeoBib" entstehende Georeferenzierte Online-Bibliographie frĂŒher Holocaust- und Lagerliteratur.
Das Dokument ist Teil der Schriftenreihe ÂGeoBib DokumentationÂ, welche die im Laufe des Projekts "GeoBib" entstehenden internen Reports umfasst und somit die fortlaufenden Projektarbeiten dokumentiert.
Ziel des Projekts GeoBib ist es, die frĂŒhen Texte der deutsch- bzw. polnischsprachigen Holocaust- und Lagerliteratur von 1933 bis 1949 zu erfassen und deren bibliographische Angaben (ohne Volltexte) in einer Online-Datenbank bereit zu stellen. So können diese frĂŒhen Texte, die in weiten Teilen aus dem kulturellen und kollektiven GedĂ€chtnis verdrĂ€ngt wurden, fĂŒr die öffentliche, wissenschaftliche und didaktische Wahrnehmung erschlossen und aufbereitet werden. Die systematische Erfassung der bis 1949 publizierten Texte sowie die Anreicherung durch exemplarische Informationen zu den Verfassern, zu gegebenenfalls erschienenen Rezensionen und SekundĂ€rliteratur orientieren sich dabei an internationalen Annotationsstandards. Metadaten und Textinhalte (Orte, Lager, Gettos etc.) werden georeferenziert, d.h. anhand von Kartenmaterial verortet und in einem geographischen Informationssystem erfasst und dargestellt. Das zu entwickelnde Web-Portal soll dabei  neben der bibliographischen Suche  auch ĂŒber geographische Karten gezielt Texte zu einer bestimmten Region auffindbar machen. Dabei sollen Abfragemöglichkeiten nach rĂ€umlichen Kriterien und bibliographischen Attributen kombinierbar sein
Der groĂe Sprung? Chinas ballistisches Raketenprogramm: Ein technischer Bericht
Seit seinen AnfĂ€ngen in den 1950er Jahren hat sich Chinas Raketenprogramm sehr stark entwickelt. Dieser Research Report zeigt auf, wie sich in einem Zeitraum von mehr 70 Jahren insbesondere die Entwicklung der ballistischen Raketen in China vollzogen hat. Dabei wertet der Autor insbesondere offene Quellen aus und nimmt eine technische Analyse dieser Daten vor. Er gibt auĂerdem einen kurzen Ăberblick ĂŒber die hierfĂŒr verantwortliche, bis heute sehr staatsnahe, chinesische Industrie sowie eine EinschĂ€tzung der aktuellen chinesischen RaketenstreitkrĂ€fte hinsichtlich operationeller Systeme, TruppenstĂ€rken und Stationierungsorten. Durch diesen Ansatz wird ersichtlich, dass China seit vielen Jahrzehnten - zunĂ€chst mit sowjetischer Hilfe, dann durch eigenstĂ€ndige Entwicklungen - weitreichende Raketensysteme als Werkzeug zur Erstellung von Bedrohungskulissen nutzt. Insbesondere in den vergangenen Jahren ist zu beobachten, dass China verstĂ€rkt in Forschung, Entwicklung und in die Produktion von Raketen investiert. Darauf weist ein signifikanter Anstieg bei Systemen mittlerer und groĂer Reichweite sowie eine weitreichende Modernisierung der vorhandenen Systeme hin. Dieser Report ist ein Nachschlagewerk zum aktuellen Stand des chinesischen Raketenprogrammes. Er soll dabei helfen, die technischen HintergrĂŒnde des chinesischen Raketenprogrammes zu verstehen und damit auch FĂ€higkeiten, Absichten und zugrundeliegende Strategien, kĂŒnftige Handlungsoptionen sowie Auswirkungen auf die internationale Staatengemeinschaft durch das chinesische Raketenprogramm besser einordnen zu können
Towards a Swiss National Research Infrastructure
In this position paper we describe the current status and plans for a Swiss
National Research Infrastructure. Swiss academic and research institutions are
very autonomous. While being loosely coupled, they do not rely on any
centralized management entities. Therefore, a coordinated national research
infrastructure can only be established by federating the various resources
available locally at the individual institutions. The Swiss Multi-Science
Computing Grid and the Swiss Academic Compute Cloud projects serve already a
large number of diverse user communities. These projects also allow us to test
the operational setup of such a heterogeneous federated infrastructure
The First Neocentric, Discontinuous, and Complex Small Supernumerary Marker Chromosome Composed of 7 Euchromatic Blocks Derived from 5 Different Chromosomes
Background: The majority of small supernumerary marker chromosomes (sSMCs) are derived from one single chromosome. Complex sSMCs instead consist of two to three genomic segments, originating from different chromosomes. Additionally, discontinuous sSMCs have been seen; however, all of them are derived from one single chromosome. Here, we reported a 41 year-old patient with infertility, hypothyroidism, rheumatism, and degenerative spine and schizoaffective disorder, being a carrier of a unique, complex, and discontinuous sSMC. Methods: The sSMC was characterized in detail by banding and molecular cytogenetics including fluorescence in situ hybridization (FISH) and array-comparative genomic hybridization (aCGH), as well as by optical genome mapping (OGM). Results: The neocentric sSMC characterized here contained seven portions of five different chromosomes and was present in ~50% of both peripheral blood cells and buccal mucosa cells. aCGH and OGM revealed gains of 8q12.3q12.3, 8q22.3â8q23.1, 9q33.3â9q34.11, 14q21.1â14q21.1, 14q21.1â14q21.2, 15q21.2â15q21.2, and 21q21.1â21q21.1. Furthermore, glass-needle based microdissection and reverse FISH, as well as FISH with locus-specific probes confirmed these results. The exact order of the involved euchromatic blocks could be decoded by OGM. Conclusions: Among the >7000 reported sSMCs in the literature, this is the only such complex, discontinuous, and neocentric marker with a centric minute shape
Crystal Structure of an Anti-Ang2 CrossFab Demonstrates Complete Structural and Functional Integrity of the Variable Domain.
Bispecific antibodies are considered as a promising class of future biotherapeutic molecules. They comprise binding specificities for two different antigens, which may provide additive or synergistic modes of action. There is a wide variety of design alternatives for such bispecific antibodies, including the "CrossMab" format. CrossMabs contain a domain crossover in one of the antigen-binding (Fab) parts, together with the "knobs-and-holes" approach, to enforce the correct assembly of four different polypeptide chains into an IgG-like bispecific antibody. We determined the crystal structure of a hAng-2-binding Fab in its crossed and uncrossed form and show that CH1-CL-domain crossover does not induce significant perturbations of the structure and has no detectable influence on target binding
Global reconstruction of language models with linguistic rules â Explainable AI for online consumer reviews
Analyzing textual data by means of AI models has been recognized as highly relevant in information systems research and practice, since a vast amount of data on eCommerce platforms, review portals or social media is given in textual form. Here, language models such as BERT, which are deep learning AI models, constitute a breakthrough and achieve leading-edge results in many applications of text analytics such as sentiment analysis in online consumer reviews. However, these language models are âblack boxesâ: It is unclear how they arrive at their predictions. Yet, applications of language models, for instance, in eCommerce require checks and justifications by means of global reconstruction of their predictions, since the decisions based thereon can have large impacts or are even mandatory due to regulations such as the GDPR. To this end, we propose a novel XAI approach for global reconstructions of language model predictions for token-level classifications (e.g., aspect term detection) by means of linguistic rules based on NLP building blocks (e.g., part-of-speech). The approach is analyzed on different datasets of online consumer reviews and NLP tasks. Since our approach allows for different setups, we further are the first to analyze the trade-off between comprehensibility and fidelity of global reconstructions of language model predictions. With respect to this trade-off, we find that our approach indeed allows for balanced setups for global reconstructions of BERTâs predictions. Thus, our approach paves the way for a thorough understanding of language model predictions in text analytics. In practice, our approach can assist businesses in their decision-making and supports compliance with regulatory requirements
A fast and sensitive method for the continuous in situ determination of dissolved methane and its d13C-isotope ratio in surface waters
A fast and sensitive method for the continuous determination of methane (CH4) and its stable carbon isotopic
values (d13C-CH4) in surface waters was developed by applying a vacuum to a gas/liquid exchange
membrane and measuring the extracted gases by a portable cavity ring-down spectroscopy analyser
(M-CRDS). The M-CRDS was calibrated and characterized for CH4 concentration and d13C-CH4 with synthetic
water standards. The detection limit of the M-CRDS for the simultaneous determination of CH4 and d13CCH4
is 3.6 nmol L21 CH4. A measurement precision of CH4 concentrations and d13C-CH4 in the range of
1.1%, respectively, 1.7& (1r) and accuracy (1.3%, respectively, 0.8& [1r]) was achieved for single measurements
and averaging times of 10 min. The response time s of 5765 s allow determination of d13C-CH4 values
more than twice as fast than other methods. The demonstrated M-CRDS method was applied and tested
for Lake Stechlin (Germany) and compared with the headspace-gas chromatography and fast membrane CH4
concentration methods. Maximum CH4 concentrations (577 nmol L21) and lightest d13C-CH4 (235.2&) were
found around the thermocline in depth profile measurements. The M-CRDS-method was in good agreement
with other methods. Temporal variations in CH4 concentration and d13C-CH4 obtained in 24 h measurements
indicate either local methane production/oxidation or physical variations in the thermocline. Therefore,
these results illustrate the need of fast and sensitive analyses to achieve a better understanding of
different mechanisms and pathways of CH4 formation in aquatic environments
Comparison of Several Methods for Determining the Internal Resistance of Lithium Ion Cells
The internal resistance is the key parameter for determining power, energy efficiency and lost heat of a lithium ion cell. Precise knowledge of this value is vital for designing battery systems for automotive applications. Internal resistance of a cell was determined by current step methods, AC (alternating current) methods, electrochemical impedance spectroscopy and thermal loss methods. The outcomes of these measurements have been compared with each other. If charge or discharge of the cell is limited, current step methods provide the same results as energy loss methods
- âŠ