OSIRIS Payload for DLR's BiROS Satellite

Direct optical communication links might offer a solution for the increasing demand of transmission capacity in satellite missions. Although direct space-to-ground links suffer from limited availability due to cloud coverage, the achievable data rates can be higher by orders of magnitude compared to traditional RF communication systems. DLR’s Institute for Communication and Navigation is currently developing an experimental communication payload for DLR’s BiROS satellite. The OSIRIS payload consists of a tracking sensor for a precise alignment between satellite and groundstation, an optical uplink channel, the two different and independent laser sources and the optical bench with the transmission optics. This paper will give an overview about the BiROS satellite, the OSIRIS payload and the performance of the system, including space-qualification of the hardware and transmission tests

Quantum simulation with fully coherent dipole--dipole-interactions mediated by three-dimensional subwavelength atomic arrays

Quantum simulators employing cold atoms are among the most promising approaches to tackle quantum many-body problems. Nanophotonic structures are widely employed to engineer the bandstructure of light and are thus investigated as a means to tune the interactions between atoms placed in their vicinity. A key shortcoming of this approach is that excitations can decay into free photons, limiting the coherence of such quantum simulators. Here, we overcome this challenge by proposing to use a simple cubic three-dimensional array of atoms to produce an omnidirectional bandgap for light and show that it enables coherent, dissipation-free interactions between embedded impurities. We show explicitly that the band gaps persist for moderate lattice sizes and finite filling fraction, which makes this effect readily observable in experiment. Our work paves the way toward analogue spin quantum simulators with long-range interactions using ultracold atomic lattices, and is an instance of the emerging field of atomic quantum metamaterials.Comment: 13 pages, 8 figure

Risks and Benefits of Technologies for Organizational Change Enablement - A Role Theory Perspective

As organizational change is omnipresent yet often challenging, organizations increasingly employ information technology (IT) to support and improve their change management. We refer to these technologies as change management mediation technologies (CMMTs). Despite their increasing relevance in practice, little is known about their successful implementation and usage as well as potential risks and benefits they encompass. To this end, we present findings from a multi-case study on two companies that utilize a CMMT to enable their employees for ongoing and future change projects, focusing especially on the digital transformation. We use role theory to describe and explain how CMMT usage can change employees’ roles and how this is connected to different risks and benefits for individuals and organizations. Thereby, we add to the growing literature on CMMTs and showcase a novel application of role theory in IS. Moreover, practical implications and opportunities for further research are discussed

Heat exchanger/reactors (HEX reactors): Concepts, technologies: State-of-the-art

Process intensification is a chemical engineering field which has truly emerged in the past few years and is currently rapidly growing. It consists in looking for safer operating conditions, lower waste in terms of costs and energy and higher productivity; and away to reach such objectives is to develop multifunctional devices such as heat exchanger/reactors for instance. This review is focused on the latter and makes a point on heat exchanger/reactors. After a brief presentation of requirements due to transposition from batch to continuous apparatuses, heat exchangers/reactors at industrial or pilot scales and their applications are described

The discovery laboratory – A student-centred experiential learning practical: Part I – Overview

Chemical Engineering’s Discovery Laboratory at Imperial College London is a practical teaching programme designed specifically to support student-centred learning at an advanced level, bridging the gap between instructions driven lab experiments and fully open ended research. In the first part of this article we present an overview of this programme with particular attention given to the design of the pedagogical framework and the execution of teaching. The teaching goal is delivered by in-depth experiential learning, where students are assigned a specific subject area to conduct their own research within a set timeframe and boundary conditions that guarantee a successful learning outcome. Academic supervisors and teaching assistants play an important role in this process, where they provide students with continuing guidance throughout. The use of research or industrial grade equipment ensures the students’ preparation for their final year research project as well as their post-graduation careers. In addition to summative assessments, students also receive formative feedback periodically from academic supervisors and teaching assistants. The Discovery Laboratory has received positive feedback from both teachers and students since its inauguration in 2011 and here we share some useful insights for the execution of such a practical teaching programme