Mobile communication systems rely on radiofrequency waves to operate. Given the popularity and ubiquity of mobile communication devices as well as network densification, the level of Electromagnetic Field (EMF) exposure to the public is expected to rise significantly over the next few years. Although there is no clear evidence linking short-term exposure to EMF emission from wireless communication systems with adverse health effects, the International Agency for Research on Cancer (IARC) has concluded that EMF radiation is possibly carcinogenic. To cope with the concerns of the general public, the European Environmental Agency has recommended non-technical precautionary approaches to minimize exposure to EMF emissions. Rather than relying on these non-technical approaches, EMF, latency, network resilience and connection density, alongside traditional criteria such as spectral efficiency and energy efficiency are expected to take centre stage in the development of 5G systems. This book focuses on innovative EMF exposure research for future generations of mobile and wireless communications. This timely publication highlights the novel work done on reducing EMF emissions in future mobile communication systems and how to develop smart integrated technical solutions.

In order to optimise the yield of wind power from existing and future wind plants, the entire breadth of the system of a plant, from the wind field to the turbine components, needs to be modelled in the design process. The modelling and simulation approaches used in each subsystem as well as the system-wide solution methods to optimize across subsystem boundaries are described in this reference. Chapters are written by technical experts in each field, describing the current state of the art in modelling and simulation for wind plant design. This comprehensive, two-volume research reference will provide long-lasting insight into the methods that will need to be developed for the technology to advance into its next generation. Volume 2 covers turbine level aerodynamics, aeroelasticity, rotors drivetrains and electrical systems, wind turbine control, offshore foundations, system optimization, and grid modelling.

This review concentrates on the progress and developments that have led to explosive growth in high power continuous wave (CW) fiber lasers over the last decade. Here we arbitrarily defined high power fiber operation as being close to a single mode in beam output with powers in the kilowatt range. This growth has largely been led by Yb fiber lasers up to now. However, in this review, we also highlight the potential for high power, high brightness operation of two alternative approaches, thulium fiber lasers that operate at 2 mm wavelength, and CW Raman fiber lasers (RFLs), which have yet to reach kW power levels.

In this chapter, we will guide the reader through development process of high average power diode pumped solid-state lasers, starting from material choice, through amplifier geometry and detailed description of the lasers at HiLASE.

Optical fibers have demonstrated, against all early predictions, that their geometry is extremely well-suited for handling high optical powers. However, over the years, many refinements have been done to the basic structure of these waveguides to allow guiding and generating high-powers. As a result of this development the fibers employed in high-power laser systems differ significantly from those typically used in other fields such as telecommunications and/or sensors. Therefore, this chapter is devoted to describing and explaining the main intricacies of those optical fiber designs presently used for high-power operation. In this context, the main goal of this chapter is that the reader gets an overview of the different fiber designs and building blocks of high-power optical fibers. The chapter is divided into three main parts: a brief historical overview of the evolution of this technology, a description of the main constituents of fibers for high-power operation (including the core, the pump cladding and materials), and, finally, an outlook in which novel trends in the design of these waveguides are briefly described.

Advances in High-Power Fiber and Diode Laser Engineering provides an overview of recent research trends in fiber and diode lasers and laser systems engineering. In recent years, many new fiber designs and fiber laser system strategies have emerged, targeting the mitigation of different problems which occur when standard optical fibers are used for making high-power lasers. Simultaneously, a lot of attention has been put to increasing the brightness and the output power of laser diodes. Both of these major laser development directions continue to advance at a rapid pace with the sole purpose of achieving higher power while having excellent beam quality. The book begins by introducing the principles of diode lasers and methods for improving their brightness. Later chapters cover quantum cascade lasers, diode pumped high power lasers, high average power LMA fiber amplifiers, high-power fiber lasers, beam combinable kilowatt all-fiber amplifiers, and applications of 2 μm thulium fiber lasers and high-power GHz linewidth diode lasers. Written by a team of authors with experience in academia and industrial research and development, and brought together by an expert editor, this book will be of use to anyone interested in laser systems development at the laboratory or commercial scale.

Characterisation and Control of Defects in Semiconductors Understanding the formation and introduction mechanisms of defects in semiconductors is essential to understanding their properties. Although many defect-related problems have been identified and solved over the past 60 years of semiconductor research, the quest for faster, cheaper, lower power, and new kinds of electronics generates an ongoing need for new materials and properties, and so creates new defect-related challenges. This book provides an up-to-date review of the experimental and theoretical methods used for studying defects in semiconductors, focussing on the most recent developments in the methods. These developments largely stem from the requirements of new materials - such as nitrides, the plethora of oxide semiconductors, and 2-D semiconductors - whose physical characteristics and manufacturing challenges are much more complex than in conventional Si/Ge or GaAs. Each chapter addresses both the identification and quantification of the defects and their characteristics, and goes on to suggest routes for controlling the defects and hence the semiconductor properties. The book provides valuable information and solutions for scientists and engineers working with semiconductors and their applications in electronics.

Flexoelectricity is a gradient electromechanical effect that exists in all solid dielectrics. The effect was first predicted in the late 1950s, but received little interest because it was expected to be small. The experimentally measured large flexoelectric response in ferroelectric ceramics led to the revival of the field in the early 2000s. In this study, the progress made in the flexoelectric field is reviewed. The authors’ focus will be primarily on the experimental studies related to the flexoelectric effect. The techniques employed to measure the flexoelectric coefficients are first summarised. A compilation of the flexoelectric coefficients of different ferroelectrics reported in the literature will be presented. An unresolved issue in this field is that the measured flexoelectric coefficients in ferroelectric materials are normally much greater than the theoretically predicted values, and the mechanisms proposed to explain this issue are discussed. Finally, the efforts toward the applications of the flexoelectric effect are reviewed.

There are many ways to harness the renewable and emissions-free energy available from the Earth's oceans. The technologies include wave energy, tidal and current energy, and energy from thermal and salinity gradients. In addition, offshore wind energy and marine (floating) solar arrays offer a possibility to exploit vast resources that are far larger than those available onshore. The potential capacities range from many hundreds of gigawatts to terawatts of generation. These technologies could contribute a significant part of the global electricity demand; they are particularly suitable for providing sustainable power to marine regions and island communities and nations. This book brings together contributions from international experts with academic and industry backgrounds to provide a systematic overview of ocean energy technologies, their readiness and modelling, as well as installation and grid connection technologies.

In this chapter, the main experimental results obtained to date on the selfhealing composite materials are reviewed. The review starts with the nanostructuration of the ruthenium Grubbs' catalyst (RGC) by means of the laser ablation process, followed by the encapsulation of the 5-ethylidene-2norbornene (ENB) liquid monomer into small capsules and the fabrication of three-dimensional (3D) microvascular nanocomposite beams by microfluidic infiltration. Special attention is given to the use of single-wall carbon nanotubes (SWCNT) material as reinforcement of the ENB healing agent from the perspective of obtaining a self-healing composite material with improved mechanical properties and, at the same time, having a fast ring-opening metathesis polymerisation (ROMP) reaction with high mechanical properties.