A Simple Nickel Catalyst Enabling an E‐Selective Alkyne Semihydrogenation

Stereoselective alkyne semihydrogenations are attractive approaches to alkenes, which are key building blocks for synthesis. With regards to the most atom economic reducing agent dihydrogen (H 2 ), only few catalysts for the challenging E ‐selective alkyne semihydrogenation have been disclosed, each with a unique substrate scope profile. Here, we show that a commercially available nickel catalyst facilitates the E ‐selective alkyne semihydrogenation of a wide variety of substituted internal alkynes. This results in a simple and broadly applicable overall protocol to stereoselectively access E ‐alkenes employing H 2 which could serve as a general method for synthesis.DFG, 352364740, Diwasserstoff-vermittelte nachhaltige BindungsknüpfungsreaktionenTU Berlin, Open-Access-Mittel - 201

Meteoritic ablation and fusion spherules in Antarctic ice

In the course of two Antarctic expeditions in 1980/1981 and 1982/1983 approximately 4 metric tons of documented ice samples were collected from the Atka Bay Ice Shelf, Antarctica, and subsequently shipped for cosmic dust studies. After filtration of the melt water, approximately 700 Antarctic spherules (AAS) in the size range of 5 to 500 microns were handpicked from the filter residue under optical microscopes. For the chemical investigation of single dust grains the following techniques were applied: scanning electron microscopy (SEM), X-ray analysis (EDAX), instrumental neutron activation analysis (INAA), laser microprobe mass analysis (LAMMA), and accelerator mass spectroscopy (AMS). For more than 95% of the total mass the bulk and trace elements were determined in single grain analyses using EDAX, INAA, and LAMMA. The element pattern of the dust particles was compared with that of typical terrestrial material and meteoritic matter. The majority of the spherules exhibited elemental compositions compatible with meteoritic element patterns

Onmacht en macht in de medische situatie

Redes uitgesproken ter gelegenheid van de aanvaarding van het ambt van gewoon hoogleraar in de medische psychologie, resp. buitengewoon hoogleraar in de psychotherapie aan de Erasmus Universiteit, op woensdag 20 maart 197

"Lend Me a Hand" – Extending the Reach of Seated VR Players in Unmodified Games Through Remote Co-Piloting

Playing virtual reality (VR) games while seated can be challenging because many games are designed for a mobile, standing player. Sitting down not only limits mobility but also the reach of the player. This is particularly problematic if the player does not have a choice in whether they play seated or standing because it then becomes an accessibility issue. We have taken the concept of co-piloting (controls shared across multiple input devices and players) and applied it to VR with the aim of extending the reach of the VR player. To demonstrate the feasibility of the concept, a software prototype was developed that allowed a second, remote, player to take over the VR player’s controllers and help them reach out. Because the prototype manipulates the SteamVR middleware and not the game, it can be used with any application that runs on SteamVR. A small formative study was conducted to inform further research and proof the concept

Stereoselective alkyne semihydrogenations with an air-stable copper(I) catalyst

An air-stable and preactivated copper(I) hydroxide/N-heteroyclic carbene (NHC) complex for alkyne semihydrogenations is reported. Next to an enhanced practicability of the process, the resulting alkenes are obtained with high Z-selectivities and no overreduction to the corresponding alkanes

Ambiguities in recurrence-based complex network representations of time series

Recently, different approaches have been proposed for studying basic properties of time series from a complex network perspective. In this work, the corresponding potentials and limitations of networks based on recurrences in phase space are investigated in some detail. We discuss the main requirements that permit a feasible system-theoretic interpretation of network topology in terms of dynamically invariant phase-space properties. Possible artifacts induced by disregarding these requirements are pointed out and systematically studied. Finally, a rigorous interpretation of the clustering coefficient and the betweenness centrality in terms of invariant objects is proposed

Study in optimization of microcircuit design Final report

Optimization of microcircuit reliabilit

The Rescue911 Emergency Response Information System (ERIS): A Systems Development Project Case

This teaching case presents a systems development project useful for courses in object-oriented analysis and design. The case has a strong focus on the business, methodology, modeling and implementation aspects of systems development. The case is centered on a fictitious ambulance and emergency services company (Rescue911). The case describes that the company’s current systems no longer meet their business requirements and outlines the need for a new systems solution. The new situation is presented in form of business requirements, a conceptual system breakdown and interviews with the stakeholders. The teaching notes present business process and object-oriented analysis diagrams to complement the case. Students are confronted with realistic and different categories of business artifacts as input for their systems development project. Suggested project deliverables are outlined