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Implementation and validation of the relativistic transient absorption theory within the dipole approximation

A relativistic transient absorption theory is derived, implemented and validated within the dipole approximation based on the time-dependent Dirac equation. In the non-relativistic limit, it is found that the absorption agrees with the well established non-relativistic theory based on the time-dependent Schrödringer equation. Time-dependent simulations have been performed using the Dirac equation

Responsibility of Action and Situated Cognition in Artefact—User Relationship

I discuss the dilution of responsibility of action and the idea of a symmetrical relationship between artefacts and humans. In doing so, I argue that meaning making is an activity unilaterally performed by agents, leading to an asymmetrical relationship between agents and artefacts. Therefore, the study of the one who is responsible for the action, the meaning-maker (with the capability to act) is

Sustainability transitions in manufacturing : the role of intellectual property

Intellectual property rights (IPR) form an important component for unlocking sustainable innovation. Research highlights both the positive role of IPR in incentivizing sustainable innovation and the negatives, such as delaying diffusion. We review the state-of-art debates on incentivizing sustainable innovations and the role of IPR for sustainable manufacturing industries, summarizing three main d

Evaluating the use of displacement ventilation for providing space heating in unoccupied periods using laboratory experiments, field tests and numerical simulations

Displacement ventilation is a proven method of providing conditioned air to enclosed spaces with the aim to deliver good air quality and thermal comfort while reducing the amount of energy required to operate the system. Until now, the practical applications of displacement ventilation have been exclusive to providing ventilation and cooling to large open spaces with high ceilings. The provision o

A python framework for solving advection-diffusion problems

This paper discusses a Python interface for the recently published Dune-Fem-DG module which provides highly efficient implementations of the Discontinuous Galerkin (DG) method for solving a wide range of non linear partial differential equations (PDE). Although the C++ interfaces of Dune-Fem-DG are highly flexible and customizable, a solid knowledge of C++ is necessary to make use of this powerful

Hp–adaptive discontinuous galerkin methods for porous media flow

We present an adaptive Discontinuous Galerkin discretization for the solution of porous media flow problems. The considered flows are immiscible and incompressible. The adaptive approach implemented allows for refinement/coarsening in both the element size and the polynomial degree. The method is evaluated using homogeneous and heterogeneous test cases.

Comparison of linear reconstructions for second-order finite volume schemes on polyhedral grids

Improved and enhanced oil recovery methods require sophisticated simulation tools to predict the injected flow pass together with the chemical reactions inside it. One approach is application of higher-order numerical schemes to avoid excessive numerical diffusion that is very typical for transport processes. In this work, we provide a first step towards higher-order schemes applicable on general

Python framework for hp-adaptive discontinuous Galerkin methods for two-phase flow in porous media

In this paper we present a framework for solving two-phase flow problems in porous media. The discretization is based on a Discontinuous Galerkin method and includes local grid adaptivity and local choice of polynomial degree. The method is implemented using the new Python frontend Dune-FemPy to the open source framework Dune. The code used for the simulations is made available as Jupyter notebook

Distributed Newest Vertex Bisection

Distributed adaptive conforming refinement requires multiple iterations of the serial refinement algorithm and global communication as the refinement can be propagated over several processor boundaries. We show bounds on the maximum number of iterations. The algorithm is implemented within the open-source software package DUNE-ALUGRID.

Asynchronous communication in spectral-element and discontinuous Galerkin methods for atmospheric dynamics - A case study using the High-Order Methods Modeling Environment (HOMME-homme-dg-branch)

The scalability of computational applications on current and next-generation supercomputers is increasingly limited by the cost of inter-process communication. We implement non-blocking asynchronous communication in the High-Order Methods Modeling Environment for the time integration of the hydrostatic fluid equations using both the spectral-element and discontinuous Galerkin methods. This allows

Comparison of dynamical cores for NWP models : Comparison of COSMO and Dune

We present a range of numerical tests comparing the dynamical cores of the operationally used numerical weather prediction (NWP) model COSMO and the university code Dune, focusing on their efficiency and accuracy for solving benchmark test cases for NWP. The dynamical core of COSMO is based on a finite difference method whereas the Dune core is based on a Discontinuous Galerkin method. Both dynami

A fast parallel solver for the forward problem in electrical impedance tomography

Electrical impedance tomography (EIT) is a noninvasive imaging modality, where imperceptible currents are applied to the skin and the resulting surface voltages are measured. It has the potential to distinguish between ischaemic and haemorrhagic stroke with a portable and inexpensive device. The image reconstruction relies on an accurate forward model of the experimental setup. Because of the rela

The DUNE framework : Basic concepts and recent developments

This paper presents the basic concepts and the module structure of the Distributed and Unified Numerics Environment and reflects on recent developments and general changes that happened since the release of the first DUNE version in 2007 and the main papers describing that state Bastian etal. (2008a, 2008b). This discussion is accompanied with a description of various advanced features, such as co