79 research outputs found

    Model Based Sensor System for Temperature Measurement in R744 Air Conditioning Systems

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    The goal is the development of a novel principle for the temperature acquisition of refrigerants in CO2 air conditioning systems. The new approach is based on measuring the temperature inside a pressure sensor, which is also needed in the system. On the basis of simulative investigations of different mounting conditions functional relations between measured and medium temperature will be derived.Comment: Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/handle/2042/16838

    THE ROLE OF ARCHITECTURE MODULARITY FOR BUSINESS PROCESS OUTSOURCING – DEVELOPING A RESEARCH MODEL

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    Recent developments force companies to rethink their value creation model and open themselves to other companies, which results in a shift from the traditional matrix or functional design to a more modular organization design. For example, even traditional banks open themselves and allow the ser-vices of specialized companies, to be integrated into their organization. Through this modular design, it is very easily possible to do it the other way around and conduct the outsourcing of certain business processes. The question that arises from this is whether and how the modularity of a firm’s architecture, consisting amongst others of the modularity of its business processes and its underlying IT support infrastructure, influences the incentive to outsource certain business processes. As a research-in-pro-gress paper, this manuscript develops a model of the multidimensional concept of modularity and links it causally to the determinants of a selective business process outsourcing (BPO) decision

    How to decompress the Pressure - The moderating Effect of IT Flexibility on the negative Impact of Governmental Pressure on Business Agility

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    In times of digital transformation banks need to behave agile and increase their speed in IT. At the same time, they are bound by an increasing number of regulatory rules at an increasing pace that force them to act carefully. Since governments frequently introduce new regulatory terms, especially in the finance sector, regulation is a changing phenomenon itself, which forces banks to adjust and change their systems constantly. To manage these challenges, we argue that successful businesses need to have a flexible IT architecture in place. This should enable them to update and reconfigure their systems in a cost effective and prompt manner. By doing this, they should be able to compensate for the regulatory pressure and remain agile. Based on an analysis of 119 survey results, we find that business agility is indeed lower for higher regulatory pressure and that this effect is mitigated by a flexible IT

    Design of a Forgetting Blockchain: A Possible Way to Accomplish GDPR Compatibility

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    Practitioners as well as academics expect that blockchain technology is a game changer for a variety of use cases. This is because of its feature of transaction immutability enabled by keeping a history of all transactions. Nevertheless, this strength can become its biggest weakness. There already exists a lively discussion on scenarios where it is necessary to delete submitted data from the chain after it is no longer needed. This becomes even more crucial with the introduction of the European General Data Protection Regulation (GDPR). In this paper we make use of a design science research (DSR) approach to design an IT artifact in form of a prototype that maintains most of the key features of blockchain technology but deletes old data. We evaluate the prototype with help of experts to investigate what to expect from blockchains that delete data and derive principles on how to design them

    Synthese und Charakterisierung von komplexen Boriden und schichtförmig aufgebauten Boridcarbiden

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    Im Rahmen dieser Arbeit wurden verschiedene Verbindungen zweier Materialklassen thermoelektrisch charakterisiert. Bei den zwei Materialklassen handelt es sich zum einen um mitunter komplexe Metall-Boride variabler Zusammensetzung. Diese Klasse kann im Speziellen in Natrium- und Scandium-Boride unterteilt werden, wobei bei letzteren Dotierungen mit Wolfram durchgeführt wurden. Die andere Materialklasse stellen schichtförmig aufgebaute Metall-Boridcarbide der Zusammensetzung M-B-C (M = Ca, Mg, Sc) dar. Grundsätzlich wurden ausgewählte Verbindungen beider Materialklassen mittels Hochtemperatursynthesen phasenrein hergestellt. Anschließend wurden die erhaltenen polykristallinen Pulver mit dem Verfahren der feldaktivierten Sintertechnik zu kompakten Presslingen verdichtet. An den kompaktierten Proben wurden die physikalischen Eigenschaften zur Bestimmung der thermoelektrischen Güte bis 1000 °C gemessen. Nach allen dieser Schritte wurden die Proben mittels Röntgenpulverdiffraktometrie darauf überprüft, ob sie durch die jeweiligen Prozessbedingungen unverändert waren. Zusätzlich zur thermoelektrischen Güte wurden Methoden wie thermische Analyse, Hochtemperatur-Röntgenpulverdiffraktometrie oder energiedispersive Röntgenspektroskopie angewandt und von ausgewählten Proben die magnetischen Eigenschaften in Bezug auf potentielle Supraleitfähigkeit untersucht

    Pushing the Upper Limit of Nucleophilicity Scales by Mesoionic N-Heterocyclic Olefins

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    A series of mesoionic, 1,2,3-triazole-derived N-heterocyclic olefins (mNHOs), which have an extraordinarily electron-rich exocyclic CC-double bond, was synthesized and spectroscopically characterized, in selected cases by X-ray crystallography. The kinetics of their reactions with arylidene malonates, ArCH=C(CO2Et)2, which gave zwitterionic adducts, were investigated photometrically in THF at 20 °C. The resulting second-order rate constants k2(20 °C) correlate linearly with the reported electrophilicity parameters E of the arylidene malonates (reference electrophiles), thus providing the nucleophile-specific N and sN parameters of the mNHOs according to the correlation lg k2(20 °C)=sN(N+E). With 21<N<32, the mNHOs are much stronger nucleophiles than conventional NHOs. Some mNHOs even excel the reactivity of mono- and diacceptor-substituted carbanions. It is exemplarily shown that the reactivity parameters thus obtained allow to calculate the rate constants for mNHO reactions with further Michael acceptors and predict the scope of reactions with other electrophilic reaction partners including carbon dioxide, which gives zwitterionic mNHO-carboxylates. The nucleophilicity parameters N correlate linearly with a linear combination of the quantum-chemically calculated methyl cation affinities and buried volumes of mNHOs, which offers a valuable tool to tailor the reactivities of strong carbon nucleophiles

    Thermal Properties of SiOC Glasses and Glass Ceramics at Elevated Temperatures

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    In the present study, the effect of the chemical and phase composition on the thermal properties of silicon oxide carbides (SiOC) has been investigated. Dense monolithic SiOC materials with various carbon contents were prepared and characterized with respect to their thermal expansion, as well as thermal conductivity. SiOC glass has been shown to exhibit low thermal expansion (e.g., ca. 3.2 × 10⁻⁶ K⁻¹ for a SiOC sample free of segregated carbon) and thermal conductivity (ca. 1.5 W/(m∙K)). Furthermore, it has been observed that the phase separation, which typically occurs in SiOC exposed to temperatures beyond 1000–1200 °C, leads to a decrease of the thermal expansion (i.e., to 1.83 × 10⁻⁶ K⁻¹ for the sample above); whereas the thermal conductivity increases upon phase separation (i.e., to ca. 1.7 W/(m∙K) for the sample mentioned above). Upon adjusting the amount of segregated carbon content in SiOC, its thermal expansion can be tuned; thus, SiOC glass ceramics with carbon contents larger than 10–15 vol % exhibit similar coefficients of thermal expansion to that of the SiOC glass. Increasing the carbon and SiC content in the studied SiOC glass ceramics leads to an increase in their thermal conductivity: SiOC with relatively large carbon and silicon carbides (SiC) volume fractions (i.e., 12–15 and 20–30 vol %, respectively) were shown to possess thermal conductivities in the range from 1.8 to 2.7 W/(m∙K

    Ultrafast hole carrier relaxation dynamics in p-type CuO nanowires

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    Ultrafast hole carrier relaxation dynamics in CuO nanowires have been investigated using transient absorption spectroscopy. Following femtosecond pulse excitation in a non-collinear pump-probe configuration, a combination of non-degenerate transmission and reflection measurements reveal initial ultrafast state filling dynamics independent of the probing photon energy. This behavior is attributed to the occupation of states by photo-generated carriers in the intrinsic hole region of the p-type CuO nanowires located near the top of the valence band. Intensity measurements indicate an upper fluence threshold of 40 μJ/cm2 where carrier relaxation is mainly governed by the hole dynamics. The fast relaxation of the photo-generated carriers was determined to follow a double exponential decay with time constants of 0.4 ps and 2.1 ps. Furthermore, time-correlated single photon counting measurements provide evidence of three exponential relaxation channels on the nanosecond timescale

    Monkeypox (Mpox) requires continued surveillance, vaccines, therapeutics and mitigating strategies

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    The widespread outbreak of the monkeypox virus (MPXV) recognized in 2022 poses new challenges for public healthcare systems worldwide. With more than 86,000 people infected, there is concern that MPXV may become endemic outside of its original geographical area leading to repeated human spillover infections or continue to be spread person-to-person. Fortunately, classical public health measures (e.g., isolation, contact tracing and quarantine) and vaccination have blunted the spread of the virus, but cases are continuing to be reported in 28 countries in March 2023. We describe here the vaccines and drugs available for the prevention and treatment of MPXV infections. However, although their efficacy against monkeypox (mpox) has been established in animal models, little is known about their efficacy in the current outbreak setting. The continuing opportunity for transmission raises concerns about the potential for evolution of the virus and for expansion beyond the current risk groups. The priorities for action are clear: 1) more data on the efficacy of vaccines and drugs in infected humans must be gathered; 2) global collaborations are necessary to ensure that government authorities work with the private sector in developed and low and middle income countries (LMICs) to provide the availability of treatments and vaccines, especially in historically endemic/enzootic areas; 3) diagnostic and surveillance capacity must be increased to identify areas and populations where the virus is present and may seed resurgence; 4) those at high risk of severe outcomes (e.g., immunocompromised, untreated HIV, pregnant women, and inflammatory skin conditions) must be informed of the risk of infection and be protected from community transmission of MPXV; 5) engagement with the hardest hit communities in a non-stigmatizing way is needed to increase the understanding and acceptance of public health measures; and 6) repositories of monkeypox clinical samples, including blood, fluids, tissues and lesion material must be established for researchers. This MPXV outbreak is a warning that pandemic preparedness plans need additional coordination and resources. We must prepare for continuing transmission, resurgence, and repeated spillovers of MPXV.We would like to thank Drs. Ming Fan at East Carolina University and Dara Wambach and her team at Johnson & Johnson for critically reviewing the manuscript.info:eu-repo/semantics/publishedVersio

    Monkeypox (Mpox) requires continued surveillance, vaccines, therapeutics and mitigating strategies

    Get PDF
    The widespread outbreak of the monkeypox virus (MPXV) recognized in 2022 poses new challenges for public healthcare systems worldwide. With more than 86,000 people infected, there is concern that MPXV may become endemic outside of its original geographical area leading to repeated human spillover infections or continue to be spread person-to-person. Fortunately, classical public health measures (e.g., isolation, contact tracing and quarantine) and vaccination have blunted the spread of the virus, but cases are continuing to be reported in 28 countries in March 2023. We describe here the vaccines and drugs available for the prevention and treatment of MPXV infections. However, although their efficacy against monkeypox (mpox) has been established in animal models, little is known about their efficacy in the current outbreak setting. The continuing opportunity for transmission raises concerns about the potential for evolution of the virus and for expansion beyond the current risk groups. The priorities for action are clear: 1) more data on the efficacy of vaccines and drugs in infected humans must be gathered; 2) global collaborations are necessary to ensure that government authorities work with the private sector in developed and low and middle income countries (LMICs) to provide the availability of treatments and vaccines, especially in historically endemic/enzootic areas; 3) diagnostic and surveillance capacity must be increased to identify areas and populations where the virus is present and may seed resurgence; 4) those at high risk of severe outcomes (e.g., immunocompromised, untreated HIV, pregnant women, and inflammatory skin conditions) must be informed of the risk of infection and be protected from community transmission of MPXV; 5) engagement with the hardest hit communities in a non-stigmatizing way is needed to increase the understanding and acceptance of public health measures; and 6) repositories of monkeypox clinical samples, including blood, fluids, tissues and lesion material must be established for researchers. This MPXV outbreak is a warning that pandemic preparedness plans need additional coordination and resources. We must prepare for continuing transmission, resurgence, and repeated spillovers of MPXV
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