The principle of the conventional activated sludge (CAS) for municipal wastewater treatment is primarily based on biological oxidation by which organic matters are converted to biomass and carbon dioxide. After more than 100-years successful application, the CAS process is receiving increasing critiques on its high-energy consumption and excessive sludge generation. Currently, almost all municipal wastewater treatment plants with the CAS as a core process are being operated in an energy-negative fashion. To tackle such challenging situations, there is a need to re-examine the present wastewater treatment philosophy by developing and adopting novel process configurations and emerging technologies. The solutions going forward should rely on the ways to improve direct energy recovery from wastewater, while minimizing in-plant energy consumption.

A set〖 F〗_q of 3-dimensional subspaces of F_q^7, the 7-dimensional vector space over the finite field F_q^7, is said to form a q-analogue of the Fano plane if every 2-dimensional subspace of F_q^7 is contained in precisely one member of F_q. The existence problem for such q-analogues remains unsolved for every single value of q. Here we report on an attempt to construct such q-analogues using ideas from the theory of subspace codes, which were introduced a few years ago by Koetter and Kschischang in their seminal work on error-correction for network coding. Our attempt eventually fails, but it produces the largest subspace codes known so far with the same parameters as a putative q-analogue. In particular we find a ternary subspace code of new record size 6977, and we are able to construct a binary subspace code of the largest currently known size 329 in an entirely computer-free manner.

Constant-dimension codes with the maximum possible minimum distance have been studied under the name of partial spreads in Finite Geometry for several decades. Not surprisingly, for this subclass typically the sharpest bounds on the maximal code size are known. The seminal works of Beutelspacher and Drake & Freeman on partial spreads date back to 1975 and 1979, respectively. From then until recently, there was almost no progress besides some computer-based constructions and classifications. It turns out that vector space partitions provide the appropriate theoretical framework and can be used to improve the long-standing bounds in quite a few cases. Here, we provide a historic account on partial spreads and an interpretation of the classical results from a modern perspective. To this end, we introduce all required methods from the theory of vector space partitions and Finite Geometry in a tutorial style. We guide the reader to the current frontiers of research in that field, including a detailed description of the recent improvements.

This book constitutes the thoroughly refereed proceedings of the 4th International Conference on Abstract State Machines, B, TLA, VDM and Z, which took place in Toulouse, France, in June 2014. The 13 full papers presented together with 3 invited talks and 19 short papers were carefully reviewed and selected from 81 submissions. The ABZ conference series is dedicated to the cross-fertilization of six related state-based and machine-based formal methods: Abstract State Machines (ASM), Alloy, B, TLA, VDM and Z. They share a common conceptual foundation and are widely used in both academia and industry for the design and analysis of hardware and software systems. The main goal of this conference series is to contribute to the integration of these formal methods, clarifying their commonalities and differences to better understand how to combine different approaches for accomplishing the various tasks in modeling, experimental validation and mathematical verification of reliable high-quality hardware/software systems.

In this study, we propose a digital twin pilot study for bridge monitoring and maintenance. In particular, an infrastructure management framework using UAV and surveillance cameras, and accelerometers-based digital twins is proposed to perform long-term and non-interruptive monitoring. Real-world monitoring data are obtained through an experimental test performed on the Juanhu bridge (Haning, Zhejiang, China). Traffic flow and accelerometer data of the tested bridge were measured. The digital twin model of the bridge is created as a real-time Finite Element model in OpenSees. The FE model geometry is produced using a 3D photogrammetric reconstruction, and its dynamic properties are updated based on Bayesian modal identification. The traffic flow information on the bridge is processed through computer vision techniques using the video footage from the UAV and surveillance cameras. The object detection algorithm YOLO and tracking algorithm DeepSORT are used to derive the time-space diagrams. These elements operate in tandem with the accelerometer data and the digital twin FE model to acquire a preliminary vehicle loading estimation. The results are presented in this study and showcase the feasibility of the proposed digital twin framework for bridge monitoring and maintenance.

In order to model and predict the weather of the near-Earth space environment, it is necessary to understand the important coupling mechanisms from the surface of the Sun to the Earth's ionosphere, including its coupling with the atmosphere below. This chapter reports the simulations of the mid-latitude to low-latitude ionosphere. Multiday simulations during the Whole Heliosphere Interval (WHI) 2008 are performed using two versions of SAMI3 model: (1) SAMI3 with externally specified E X B drifts and (2) SAMI3 with a potential solver to self-consistently specify electric fields. The results are compared with GPS-derived global total electron content (TEC) maps. The chapter details the E X B drifts calculated by the self-consistent SAMI3 and compares these results with an empirical model. It provides initial results for a multi-year run of the descending phase of Solar Cycle 23 to illustrate the broader range of Integrated Sun-Earth System (ISES) activity underway.

Electrochemical capacitors have been developing fast in recent years, and are slowly becoming an increasingly important component in the energy storage mix. Their particular properties, high power density, and medium energy densities, have made them suitable for a growing number of applications such as regenerative breaking and fast charging toys.

In this chapter, we present a review of our continuing efforts toward the development of discrete, low-dimensional nanostructured carbon-based electron emitters. Carbon nanotubes and nanofibers, herein referred to simply as CNTs, are one-dimensional carbon allotropes formed from cylindrically rolled and nested graphenesheets, have diameters between 1 and 500 nm and lengths of up to several millimeters,and are perfect candidates for field emission (FE) applications. By virtue of their extremely strong sp2 C-C bonding, intrinsic to the graphene hexagonal lattice, CNTs have demonstrate dimpressive chemical inertness, unprecedented thermal stabilities, significant resistance to electromigration, and exceptionally high axial current carrying capacities, even at elevated temperatures. These near ideal cold cathode electron emitters have incredibly high electric field enhancing aspect ratios combined with virtual point sources of the order of a few nanometers in size. The correct integration and judicious development of suitable FE platforms based on these extraordinary molecules is critical and will ultimately enable enhanced technologies.
This chapter will review some of the more recent platforms, devices and structures developed by our group, as well as our contributions towards the development of industry-scalable technologies for ultra-high-resolution electron microscopy, portable x-ray sources, and flexible environmental lighting technologies.

The Sun, the largest obiect in the Solar System, is positioned some 150 million kilometres from the Earth's surface and generates its electricity through fusion reactions, converting its hydrogen into both helium and emitted energy. The solar radiation is emitted at a temperature of about 6,000K and a power density of 63.1MW per metre squared from its surface. This is attenuated and dispersed significantly, until it is received by the Earth's atmosphere at approximately 1,300W per metre squared. The amount of energy received from the Sun in just one hour is actually more than the world consumes in an entire year. Figure 4.1 shows the global solar radiation distribution. The light received is an entire spec-trum of wavelengths, ranging from 300 nanometres (ultraviolet region) to about 2 micrometres (infrared region). The peak of the spectrum is in
the visible region (McDaniels, 1979).Nature has derived energy from the Sun for millions of years, mainly through the process of photosynthesis. Other forms of renewable energy are also dependent on the Sun - for example, hydroelectricity and wind and wave power. The generation of electricity from solar energy has come into fruition only since the 1950s. Today there are a multitude of applications, broadly categorised into two types: in remote areas (off-grid), or in supplying grid electricity (on-grid). To convert solar energy into electricity, a solar cell is required. A solar cell can be simply under-stood as a battery whereby the charge at the two electrodes is maintained by the absorption of light, rather than through chemical reactions in the electrolyte of the battery.

In this chapter, the photovoltaic properties occurring in single-wall carbon nanotubes (SWNTs)–donor conjugated polymer composites are reported. Photovoltaic devices based on the dispersed heterojunction concept, containing a blend of SWNTs and soluble poly(3-octylthiophene) (P3OT) were studied. The nanotubes not only act as electron acceptors, but also allow the electrons to transport efficiently along their length. The diodes (Al/polymer–nanotube com-posite/ITO) with low nanotube concentration (1%) show photovoltaic behavior, with an open circuit voltage of 0.75 V. The short circuit current is increased by two orders of magnitude compared with the pristine polymer diodes and the fill factor (ff) also increases from 0.3 to 0.4 for the nanotube–polymer cells. It is proposed that the photovoltaic response of these devices is based on the introduction of internal polymer–nanotube junctions within the polymer matrix, which due to a photoinduced electron transfer from the polymer to the nanotube contribute to enhanced charge separation and collection.