1.

Record Nr.

UNINA9910404081903321

Autore

Glawion Dorit

Titolo

Radio Galaxies at TeV Energies

Pubbl/distr/stampa

MDPI - Multidisciplinary Digital Publishing Institute, 2020

ISBN

3-03928-751-6

Descrizione fisica

1 online resource (188 p.)

Soggetti

Astronomy, space and time

Lingua di pubblicazione

Inglese

Formato

Materiale a stampa

Livello bibliografico

Monografia

Sommario/riassunto

It is common believe that the centers of all galaxies exhibit supermassive black holes with masses ranging from millions up to billions of the mass of our Sun. By accreting surrounding matter, the luminosity of these galactic nuclei can outshine the emission of their host galaxies. If this is the case, they are called active galactic nuclei. Some of these objects eject powerful outflows composed of plasma, called jets. These jets can produce non-thermal radiation which observable across the entire electromagnetic spectrum from radio up to the gamma-ray frequencies. At highest frequencies (TeV range) most of the detected active galaxies have jets directed along or close to the line of sight. However, also galaxies with larger angles to the line of sight showing fascinating features were discovered, in seeming contradiction to traditional models for these so-called radio galaxies. Thus, the latter are of particular importance for understanding active galactic nuclei in general. This Special Issue contains reviews and research articles about the current knowledge of radio galaxies at TeV energies, including observational results and theoretical models. It is intended to guide the interested reader deeper into this fascinating discipline of modern day astronomy.



2.

Record Nr.

UNINA9910557659903321

Autore

Abd-Alhameed Raed A

Titolo

Recent Technical Developments in Energy-Efficient 5G Mobile Cells

Pubbl/distr/stampa

Basel, Switzerland, : MDPI - Multidisciplinary Digital Publishing Institute, 2020

Descrizione fisica

1 online resource (292 p.)

Soggetti

History of engineering and technology

Lingua di pubblicazione

Inglese

Formato

Materiale a stampa

Livello bibliografico

Monografia

Sommario/riassunto

This book addresses the true innovation in engineering design that may be promoted by blending together models and methodologies from different disciplines, and, in this book, the target was exactly to follow this approach to deliver a new disruptive architecture to deliver these next-generation mobile small cell technologies. According to this design philosophy, the work within this book resides in the intersection of engineering paradigms that includes "cooperation", "network coding", and "smart energy-aware frontends". These technologies will not only be considered as individual building blocks, but re-engineered according to an inter-design approach resulting in the enabler for energy efficient femtocell-like services on the move. The book aims to narrow the gap between the current networking technologies and the foreseen requirements that are targeted at the future development of the 5G mobile and wireless communications networks in terms of the higher networking capacity, the ability to support more users, the lower cost per bit, the enhanced energy efficiency, and adaptability to new services and devices (for example, smart cities, and the Internet of things (IoT)).