Sökresultat

This dissertation covers studies of excited state processes in two types of solar energy materials: alternating polyfluorene polymers and their blends with fullerenes in the active layer of plastic solar cells, and bis-tridentate RuII-polypyridyl complexes to be used as sensitizer in systems for artificial photosynthesis. The polymer:fullerene blends were studied by transient absorption and time-

This study contributes to the establishment of frequency recommendations for use in coda wave interferometry structural health monitoring (SHM) systems for concrete structures. To this end, codas with widely different central frequencies were used to detect boreholes with different diameters in a large concrete floor slab, and to track increasing damage in a small concrete beam subjected to bendin

Access to local nearshore wave climate conditions on a detailed spatial scale is important for many coastal engineering practices. These include assessing the flood risk of coastal infrastructure, designing coastal protection measures, and estimating sediment transport processes and wave run-up. The present study displays a multi-scale wave modelling approach using the numerical wave model SWAN (B

The widespread international interest in the Nordic region and the mobility of Nordic brand imaginaries call for more research into the global relevance of Nordic place-branding practices. This book offers a timely attempt to unpack the specificity of the Nordic in regard to place branding by gathering different transdisciplinary accounts written by researchers in marketing, tourism, geography, co

Wave damping in vegetation in shallow lakes reduces resuspension and thereby improves the light climate and decreases nutrient recycling. In this study, wave transformation in reed (Phragmites australis) was measured in a shallow lake. Theoretical models of wave height decay, based on linear wave theory, and transformation of the probability density function (PDF), using a wave-by-wave approach, w

A generalized Green's function technique for wave propagation of transient fields in one-dimensional media is developed. The medium is partitioned into an arbitrary number of subslabs for which Green operators that map the incident field to the internal fields are defined. Relations between the Green operators for the entire medium and the Green operators for the subslabs are derived. The techniqu

We use a train of sub-200 attosecond extreme ultraviolet (XUV) pulses with energies just above the ionization threshold in argon to create a train of temporally localized electron wave packets. We study the energy transfer from a strong infrared (IR) laser field to the ionized electrons as a function of the delay between the XUV and IR fields. When the wave packets are born at the zero crossings o

This paper concerns propagation of transient electromagnetic waves in laterally discontinuous dispersive media. The approach, used here, employs a component decomposition of all fields. Specifically, the propagation operator that maps a transverse field on one plane to another plane is specified. Expansion of this mapping near the wave front determines the precursor or forerunner of the problem.

This paper concerns propagation of transient electromagnetic waves in laterally discontinuous dispersive media. The approach, used here, employs a component decomposition of all fields. Specifically, the propagation operator that maps a transverse field on one plane to another plane is specified. Expansion of this mapping near the wave front determines the precursor or forerunner of the problem.

Brand activism has emerged as a prevalent phenomenon where brands engage in socio-political issues to differentiate themselves and build stakeholder resonance. Despite its growing prominence, research on brand activism is limited, particularly in relation to brand positioning. Thus, the purpose of this study is to explore how a newly launched brand engaging in socio-political agendas communicates

Today, many projects about Electric Vehicles (EVs) and Hybrid Electric Vehicles (HEVs) are in progress within the automotive industry. Fuel-efficiency and reduction of carbon dioxide emissions from vehicles are the main targets. This thesis is within in one of these projects that is called electric All Wheel Drive(eAWD) at BorgWarner TorqTransfer Systems AB. A key parameter to perform an accurate

Sensing technologies offer several advantages for industrial tooling. In mechanical processing and manufacturing environments, sensors can be used to monitor process conditions, support predictive maintenance, reduce unnecessary material losses, and improve overall production efficiency. Therefore, as manufacturing systems become more advanced and data-driven, the integration of sensors has become

The purpose of this paper is to investigate the potential of complex or exotic materials in radome and antenna design. The existing analysis methods need to be extended to cope with these materials in generic radome and antenna geometries. This paper focuses on electromagnetic properties of the material, the means of realizations, and the methods of computations. The main objectives of this paper

We examine how the generation and propagation of high-order harmonics in a partly ionized gas medium affect their strength and synchronization. The temporal properties of the resulting attosecond pulses generated in long gas targets can be significantly influenced by macroscopic effects, in particular by the intensity in the medium and the degree of ionization which control the dispersion. Under s

A fundamental problem in robotics is generating the motion for a task. How to translate a task to motion or a series of movements is a non-trivial problem. The complexity of the task, the structure of the robot, and the desired performance determine the sequence of movements, the path, and the course of motion as a function of time, namely the trajectory. As we discuss in this thesis, a trajectory

https://www.cec.lu.se/sv/forskning/forskargrupper/kvantberakningar - 2026-07-21