Waste biomass includes agricultural residues, livestock wastes, municipal wastes and industrial organic wastes. It should be utilised or otherwise, it will cause the pollution of water, soil and even the atmosphere. Gas biofuels have attracted growing attention as a renewable and clean energy carrier. Gas biofuels include biogas, biohydrogen and its mixture i.e. biohythane, which can be produced via anaerobic fermentation or other processes from waste biomass. This book focuses on the principles of gas biofuels in terms of types of biofuels, biomass species, and reactor configuration and production pathway. A number of books focus on the production of biogas or biohydrogen alone. In comparison, this book emphasizes the interactions and common knowledge of both. In addition, the potential of new technologies, such as microbial electrochemical technologies, and two-stage fermentation on gas biofuel production are highlighted and specifically discussed based on the authors' research basis. This book provides a state-of-the-art technological insight into the production of gas biofuels from waste biomass. Specifically, this book consists of three parts. In Part I, the principles for gas biofuels production from waste biomass, including biogas production (Chapter 1) and biohydrogen production (Chapter 2). Part II focuses on the technical advances on gas biofuels production. Pre-treatment of biomass was firstly introduced in Chapter 3, whereas the advances of biogas production from high-solid wastes were discussed in Chapter 4 and Chapter 5. In comparison, biohydrogen production is reviewed not only through dark fermentation (Chapter 6) but also emerging microbial electrochemical technology (Chapter 7). The co-production of biohydrogen and biomethane is reviewed in Chapter 8. In addition to the utilisation of carbon and hydrogen stored in biomass, nutrients recycling through algae technology is discussed in Chapter 9. Part III discusses the scale-up and industrialization of biofuels. An industrial case is introduced to analyse the bottlenecks and perspectives for development of gas biofuels.

This book introduces the concepts of mobility data and data-driven urban traffic monitoring. A typical framework of mobility data-based urban traffic monitoring is also presented, and it describes the processes of mobility data collection, data processing, traffic modelling, and some practical issues of applying the models for urban traffic monitoring. This book presents three novel mobility data-driven urban traffic monitoring approaches. First, to attack the challenge of mobility data sparsity, the authors propose a compressive sensing-based urban traffic monitoring approach. This solution mines the traffic correlation at the road network scale and exploits the compressive sensing theory to recover traffic conditions of the whole road network from sparse traffic samplings. Second, the authors have compared the traffic estimation performances between linear and nonlinear traffic correlation models and proposed a dynamical non-linear traffic correlation modelling-based urban traffic monitoring approach. To address the challenge of involved huge computation overheads, the approach adapts the traffic modelling and estimations tasks to Apache Spark, a popular parallel computing framework. Third, in addition to mobility data collected by the public transit systems, the authors present a crowdsensing-based urban traffic monitoring approach. The proposal exploits the lightweight mobility data collected from participatory bus riders to recover traffic statuses through careful data processing and analysis. Last but not the least, the book points out some future research directions, which can further improve the accuracy and efficiency of mobility data-driven urban traffic monitoring at large scale. This book targets researchers, computer scientists, and engineers, who are interested in the research areas of intelligent transportation systems (ITS), urban computing, big data analytic, and Internet of Things (IoT). Advanced level students studying these topics benefit from this book as well.

Fuel cell technology has gained increasing attentions as it provides a promising sustainable approach for facing the existing energy crisis and environmental concerns. Fuel cell based power generation has been proposed to be applied in transport and distributed energy supply. However, the development of fuel cell is still in its early stages, which must overcome several issues before its commercial application, such as cost, process efficiency and working stability. This book provides a general picture on the development of fuel cells. In particular, two representative fuel cells, (ie: PEM fuel cells and solid oxide fuel cells), were reviewed in detail. The book is intended to serve as a reference for both researchers and postgraduate students within the field of chemical/biological fuel cells.