Towards an All-Silicon DV-QKD Transmitter Sourced by a Ge-on-Si Light Emitter

We investigate the behavior of a Ge-on-Si light source and demonstrate its feasibility for polarization-encoded discrete-variable quantum key distribution following the BB84 protocol, enabling a potential "all-silicon" QKD scheme which can operate well below the necessary QBER limit and successfully generate secret keys

Entanglement generation and routing in optical networks

New telecom wavelength sources of polarization entangled photon pairs allow the distribution of entanglement through metro-access networks using standard equipment. This is essential to ease the deployment of future applications that can profit from quantum entanglement, such as quantum cryptography

Structural evolution after oxidative pretreatment and CO oxidation of Au nanoclusters with different ligand shell composition: a view on the Au core

The reactivity of supported monolayer protected Au nanoclusters is directly affected by their structural dynamics under pretreatment and reaction conditions. The effect of different types of ligands of Au clusters supported on CeO$_2$ on their core structure evolution, under oxidative pretreatment and CO oxidation reaction, was investigated. X-ray absorption and X-ray photoelectron spectroscopy studies revealed that the clusters evolve to a similar core structure above 250 °C in all the cases, indicating the active role of the ligand–support interaction in the reaction

Integration of quantum key distribution in metropolitan area networks

The deployment of Quantum Key Distribution forces the development of QKD-links to be operated in current and next-generation photonic metro-access networks. These highly heterogeneous architectures determine the conditions QKD-links need to be optimized for

Oncoplastic breast consortium recommendations for mastectomy and whole breast reconstruction in the setting of post-mastectomy radiation therapy

Aim: Demand for nipple-and skin-sparing mastectomy (NSM/SSM) with immediate breast reconstruction (BR) has increased at the same time as indications for post-mastectomy radiation therapy (PMRT) have broadened. The aim of the Oncoplastic Breast Consortium initiative was to address relevant questions arising with this clinically challenging scenario. Methods: A large global panel of oncologic, oncoplastic and reconstructive breast surgeons, patient advocates and radiation oncologists developed recommendations for clinical practice in an iterative process based on the principles of Delphi methodology. Results: The panel agreed that surgical technique for NSM/SSM should not be formally modified when PMRT is planned with preference for autologous over implant-based BR due to lower risk of long-term complications and support for immediate and delayed-immediate reconstructive approaches. Nevertheless, it was strongly believed that PMRT is not an absolute contraindication for implant-based or other types of BR, but no specific recom-mendations regarding implant positioning, use of mesh or timing were made due to absence of high-quality evidence. The panel endorsed use of patient-reported outcomes in clinical practice. It was acknowledged that the shape and size of reconstructed breasts can hinder radiotherapy planning and attention to details of PMRT techniques is important in determining aesthetic outcomes after immediate BR. Conclusions: The panel endorsed the need for prospective, ideally randomised phase III studies and for surgical and radiation oncology teams to work together for determination of optimal sequencing and techniques for PMRT for each patient in the context of BRPeer reviewe

Roadmap on exsolution for energy applications

Over the last decade, exsolution has emerged as a powerful new method for decorating oxide supports with uniformly dispersed nanoparticles for energy and catalytic applications. Due to their exceptional anchorage, resilience to various degradation mechanisms, as well as numerous ways in which they can be produced, transformed and applied, exsolved nanoparticles have set new standards for nanoparticles in terms of activity, durability and functionality. In conjunction with multifunctional supports such as perovskite oxides, exsolution becomes a powerful platform for the design of advanced energy materials. In the following sections, we review the current status of the exsolution approach, seeking to facilitate transfer of ideas between different fields of application. We also explore future directions of research, particularly noting the multi-scale development required to take the concept forward, from fundamentals through operando studies to pilot scale demonstrations

Retrospective, multicenter analysis comparing conventional with oncoplastic breast conserving surgery: oncological and surgical outcomes in women with high-risk breast cancer from the OPBC-01/iTOP2 study

Introduction: Recent data suggest that margins ≥2 mm after breast-conserving surgery may improve local control in invasive breast cancer (BC). By allowing large resection volumes, oncoplastic breast-conserving surgery (OBCII; Clough level II/Tübingen 5-6) may achieve better local control than conventional breast conserving surgery (BCS; Tübingen 1-2) or oncoplastic breast conservation with low resection volumes (OBCI; Clough level I/Tübingen 3-4). Methods: Data from consecutive high-risk BC patients treated in 15 centers from the Oncoplastic Breast Consortium (OPBC) network, between January 2010 and December 2013, were retrospectively reviewed. Results: A total of 3,177 women were included, 30% of whom were treated with OBC (OBCI n = 663; OBCII n = 297). The BCS/OBCI group had significantly smaller tumors and smaller resection margins compared with OBCII (pT1: 50% vs. 37%, p = 0.002; proportion with margin <1 mm: 17% vs. 6%, p < 0.001). There were significantly more re-excisions due to R1 (“ink on tumor”) in the BCS/OBCI compared with the OBCII group (11% vs. 7%, p = 0.049). Univariate and multivariable regression analysis adjusted for tumor biology, tumor size, radiotherapy, and systemic treatment demonstrated no differences in local, regional, or distant recurrence-free or overall survival between the two groups. Conclusions: Large resection volumes in oncoplastic surgery increases the distance from cancer cells to the margin of the specimen and reduces reexcision rates significantly. With OBCII larger tumors are resected with similar local, regional and distant recurrence-free as well as overall survival rates as BCS/OBCI

CO2 utilization via methane dry reforming

Abweichender Titel nach Übersetzung der Verfasserin/des VerfassersDer Kampf gegen den Klimawandel ist eine der großen Herausforderungen dieser Generation und während fossile Brennstoffe noch immer den Großteil der globalen Energiequellen darstellen, steigen damit verbunden die Konzentrationen von Treibhausgasen in der Atmosphäre [1, 2], während nach wirtschaftlichen erneuerbaren Energiequellen gesucht wird. Zwei der wichtigsten Treibhausgase, die zur globalen Erwärmung beitragen, sind CH4 und CO2 [3]. Daher wäre eine Nutzbarmachung dieser Gase, bspw. durch Umwandlung in technologisch wertvolles Synthesegas (eine Mischung aus H2 und CO), erstrebenswert. Synthesegas kann dann in Flüssigbrennstoffe, langkettige Kohlenwasserstoffe oder Methanol umgewandelt werden [4-6]. Die Reaktion von CO2 und CH4 kann auf vielen verschiedenen Wegen realisiert werden, zum Beispiel durch Methan Dampfreformierung, Methan Trockenreformierung oder partielle Oxidation von Methan. Dabei hat die Methan Trockenreformierung einen 20 % geringeren Energieaufwand als andere Reformierungsrouten [7], obwohl es dabei zur erheblichen Koksablagerung am Katalysator kommen kann.In dieser Arbeit wurden einige neue Katalysatoren auf Basis von Oxiden in der Perowskitstruktur auf ihre Fähigkeit hin untersucht, die Methan Trockenreformierung zu katalysieren. Die Katalysatoren wurden so gewählt, dass sie über eine stabile Kristallstruktur verfügen, und wurden mit den katalytisch aktiven Metallen Ni and Co dotiert [1, 8]. Diese Metalle können, durch einen Prozess der Exsolution heißt, Nanopartikel an der Oberfläche bilden. Die Katalysatoren wurden in ihrem Dotierungsgehalt, ihrer Kristallitgröße (durch Sintern) und ihrer Vorbehandlung variiert, um den Effekt von Exsolution und daraus entstehenden Nanopartikeln zu beobachten. Außerdem wurden Dauerversuche und Experimente zu in-situ Exsolution durchgeführt. Um die Änderungen der Katalysatoren während der Reaktion zu beobachten, wurde Röntgenphotoelektronenspektroskopie fast bei Umgebungsdruck (engl. near ambient pressure X-ray spectroscopy) durchgeführt.Die Experimente haben gezeigt, dass alle dotierten Katalysatoren Aktivierung (d. h. erhöhte Aktivität) zeigen, wenn sie in reduzierender Atmosphäre vorbehandelt werden, was eine aktivierende Wirkung der ex-situ Exsolution nahelegt. In-situ Exsolution wurde für die Ni-dotierten Katalysatoren beobachtet, da sie aktiver wurden, wenn sie zweimal hintereinander verwendet wurden. Außerdem haben die NAP-XPS Experimente gezeigt, dass sich während der Reaktion Ni0 formt, was auf metallische Nanopartikel hindeutet. Es konnte weiters gezeigt werden, dass die Ni-dotierten Katalysatoren aktiver als die Co-dotierten sind. Das Sintern hatte einen aktivierenden Effekt. Die Dauerversuche zeigten eine schwache Deaktivierung der Katalysatoren zu Beginn, die Aktivität stabilisierte sich aber nach etwa einer Stunde für die meisten Katalysatoren.The battle against climate change is one of the great challenges of this generation, and as fossil fuels still represent the major energy source for the global economy, the search for renewable energy sources continues as the levels of greenhouse gases in the atmosphere rise [1, 2]. Two major greenhouse gases contributing to global warming are CO2 and CH4 [3]. Therefore, utilization of these gases, for instance by conversion into technologically valuable products such as syngas (a mixture of H2 and CO), would be desirable. Syngas can then be further converted into liquid fuels, long chain hydrocarbons or methanol [4-6]. The conversion of CH4 and CO2 can be performed by a variety of reaction pathways, including methane steam reforming, methane dry reforming or partial oxidation. Methane dry reforming has a 20 % lower operating cost than other reforming routes [7], even though there is the problem of coke deposition on the catalyst.In this thesis, several novel perovskite oxide catalysts were investigated regarding their potential to catalyse methane dry reforming. The catalysts were designed in such a way that they form a stable crystal structure and were additionally doped with the catalytically promising elements Ni and Co [1, 8]. These elements can form nanoparticles on the surface in a process called exsolution. The catalysts were varied with respect to their amount of doping, their crystalite size (through sintering) and their pre-treatments to investigate the effect of exsolution and the catalytic activity of exsolved nanoparticles. Additionally, stability tests and experiments to investigate in-situ exsolution were performed. To further understand changes that the catalysts undergo during reactions, in-situ near ambient pressure X-ray photoelectron spectroscopy (NAP-XPS) during methane dry reforming was performed.The experiments showed activation of all doped catalysts when a pre-treatment in reducing conditions was performed, indicating a performance enhancing effect of previous ex-situ exsolution. In-situ exsolution was observed for the Ni-doped catalysts, since they increased their activity in two consecutive runs performed with the same catalyst. Moreover, the NAP-XPS experiments showed the formation of Ni0 during the reaction, indicating the formation of metallic nanoparticles. It was further shown that the Ni-doped catalysts outperform their Co-doped counterparts under the same conditions. The sintering of the catalysts had an activating effect on the catalysts. Theiistability tests showed a slight deactivation effect in the beginning, but the activity stabilized after about an hour of reaction time for most catalysts.8

Zulässigkeit von Kettenarbeitsverträgen in der Rechtsprechung des EuGH

Die vorliegende Arbeit beleuchtet die nationalen gesetzlichen und kollektivvertraglichen Bestimmungen, sowie die ständige Rechtsprechung des OGH zu befristeten Arbeitsverhältnissen und deren Verlängerung (Kettenarbeitsverhältnisse). Neben der Analyse der Rechtsprechung des EuGH zur genannten Thematik wird darüber hinaus die BefristungsRL und deren Umsetzung in österreichisches Recht behandelt. Am Beispiel Deutschland wird die Umsetzung der BefristungsRL in anderen EU-Mitgliedstaaten erläutert. Im Ergebnis der Untersuchung scheint Handlungsbedarf hinsichtlich der Schaffung von umfassenderen nationalen Regelungen zu befristeten Arbeitsverhältnissen und etwaigen Verlängerungsmöglichkeiten dieser Befristungen