27 research outputs found
Multi-dimensional modeling and simulation of semiconductor nanophotonic devices
Self-consistent modeling and multi-dimensional simulation of semiconductor nanophotonic devices is an important tool in the development of future integrated light sources and quantum devices. Simulations can guide important technological decisions by revealing performance bottlenecks in new device concepts, contribute to their understanding and help to theoretically explore their optimization potential. The efficient implementation of multi-dimensional numerical simulations for computer-aided design tasks requires sophisticated numerical methods and modeling techniques. We review recent advances in device-scale modeling of quantum dot based single-photon sources and laser diodes by self-consistently coupling the optical Maxwell equations with semiclassical carrier transport models using semi-classical and fully quantum mechanical descriptions of the optically active region, respectively. For the simulation of realistic devices with complex, multi-dimensional geometries, we have developed a novel hp-adaptive finite element approach for the optical Maxwell equations, using mixed meshes adapted to the multi-scale properties of the photonic structures. For electrically driven devices, we introduced novel discretization and parameter-embedding techniques to solve the drift-diffusion system for strongly degenerate semiconductors at cryogenic temperature. Our methodical advances are demonstrated on various applications, including vertical-cavity surface-emitting lasers, grating couplers and single-photon sources
Prospective Observational Study on acute Appendicitis Worldwide (POSAW)
Acute appendicitis (AA) is the most common surgical disease, and appendectomy is the treatment of choice in the majority of cases. A correct diagnosis is key for decreasing the negative appendectomy rate. The management can become difficult in case of complicated appendicitis. The aim of this study is to describe the worldwide clinical and diagnostic work-up and management of AA in surgical departments.info:eu-repo/semantics/publishedVersio
Improved treatment results in childhood acute myelogenous leukemia: a report of the German cooperative study AML-BFM-78
Improved treatment results in childhood acute myelogenous leukemia: a report of the German cooperative study AML-BFM-78
The Asphalting of America: How the Government Subsidizes Highway Pollution in the Boswash Smog Bank
Imperializing Norden
The two pre-Napoleonic Nordic polities are best understood as empires. Drawing on recent analytical and historical scholarship on empires, I argue that 17th and 18th century Denmark, on which the piece concentrates, was very much akin to the other European empires existing at the time. Read in this light, national identities within the fragments of the empire appear similar. Nationalisms are all shaped directly on the Danish model, having at the same time Denmark as their constitutive cultural other. The introduction notes that, where all European imperial experiences are concerned, overseas territories had the most wounds inflicted upon them. We would not know this if we considered Faroese, Icelandic and Norwegian nationalism in isolation. These polities, Norway in particular, participated in and benefited from the colonial policies of the empire. This notwithstanding, their national identities insist that these nations were on the receiving – as opposed to the imposing – end of imperialism. This is a historically unwarranted and ethically problematic stance requiring further discussion