Opportunities from Renewable Resources: From biobased chemicals to biomaterials

Renewable resources and materials are considered as sustainable alternatives to their petroleum-derived counterparts which are often associated with negative social and environmental impact. In particular, where renewable resources occur as a by-product or waste as a consequence of primary and secondary processing, they can be viewed as a potential source of carbon neutral biobased chemicals, materials and (bio)energy through a process termed valorization. This thesis presents the valorization of unavoidable food supply chain wastes (UFSCW), namely, pea-, ginger- and agricultural straw-waste to afford biobased chemicals, materials and (bio)energy. Pea and ginger wastes were successfully defibrillated in to microfibrillated celluloses (MFC) via acid-free microwave hydrothermal treatment as evidenced by changes in IR, TGA, 13C CPMAS NMR, SEM, TEM, XRD, CrI and their ability to form hydrogels. The hydrolysate was rich in sugars, organic acids and, interestingly, starch (only for ginger waste). The effect of extrusion on pea waste gave higher CrI (approx. 1%-15%) and thermal stability (around 1-11oC), reduced lignin and hemicellulose content, narrower fibril width (about 0.4-3.3 nm), better water holding capacity (5 to 40 % higher) and higher surface area compared (approx. 7-20 m2/g) with their non-extruded counterparts. Ginger essential oils were successfully isolated in good yield (heptane; ~4%) with a composition similar to industrial grade ginger oil. Microwave pyrolysis of ginger afforded hydrochars (20 - 24.5 MJ kg−1) and bio-oils of variable quality dependent on the processing conditions. Bioboards (maximum IBS:0.25 N/mm2) were successfully manufactured from agri-straws and biosilicate binders, and initial attempts to produce foam materials, as an inner layer of a structural insulation panel (SIP) are reported. Preliminary attempts to increase hydrophobicity via silanization are reported. In conclusion, this thesis shows that biorefineries that deliver chemicals, materials and (bio)energy can be envisaged from valorization of pea, ginger and agri-straw UFSCWs

Winning and losing in the creative industries: an analysis of creative graduates' career opportunities across creative disciplines

Following earlier work looking at overall career difficulties and low economic rewards faced by graduates in creative disciplines, the paper takes a closer look into the different career patterns and economic performance of “Bohemian” graduates across different creative disciplines. While it is widely acknowledged in the literature that careers in the creative field tend to be unstructured, often relying on part-time work and low wages, our knowledge of how these characteristics differ across the creative industries and occupational sectors is very limited. The paper explores the different trajectory and career patterns experienced by graduates in different creative disciplinary fields and their ability to enter creative occupations. Data from the Higher Education Statistical Agency (HESA) are presented, articulating a complex picture of the reality of finding a creative occupation for creative graduates. While students of some disciplines struggle to find full-time work in the creative economy, for others full-time occupation is the norm. Geography plays a crucial role also in offering graduates opportunities in creative occupations and higher salaries. The findings are contextualised in the New Labour cultural policy framework and conclusions are drawn on whether the creative industries policy construct has hidden a very problematic reality of winners and losers in the creative economy

Heat extraction from HTS tape stacks applied in a superconducting motor in different cooling conditions

Abstract The heat is generated inside the stack of superconducting tapes mounted on the surface of the electrical machine rotor during its operation and magnetization. Cooling of such stack presents challenges because of the layered structure of both tape, and stack. Moreover, the tapes should be electrically isolated to minimize the AC losses, that assumes gluing them, rather than soldering. The calculations consider a conductive heat dissipation also through the rotor iron. Results show that: liquid nitrogen provides an effective cooling; the temperature of the stack shows complex distribution patterns with the gaseous coolant. Additional preventive measures were analyzed to keep the stack operational in vacuum conditions.</jats:p

Vision-based control of multi-agent systems

Scope and Methodology of Study: Creating systems with multiple autonomous vehicles places severe demands on the design of decision-making supervisors, cooperative control schemes, and communication strategies. In last years, several approaches have been developed in the literature. Most of them solve the vehicle coordination problem assuming some kind of communications between team members. However, communications make the group sensitive to failure and restrict the applicability of the controllers to teams of friendly robots. This dissertation deals with the problem of designing decentralized controllers that use just local sensor information to achieve some group goals.Findings and Conclusions: This dissertation presents a decentralized architecture for vision-based stabilization of unmanned vehicles moving in formation. The architecture consists of two main components: (i) a vision system, and (ii) vision-based control algorithms. The vision system is capable of recognizing and localizing robots. It is a model-based scheme composed of three main components: image acquisition and processing, robot identification, and pose estimation.Using vision information, we address the problem of stabilizing groups of mobile robots in leader- or two leader-follower formations. The strategies use relative pose between a robot and its designated leader or leaders to achieve formation objectives. Several leader-follower formation control algorithms, which ensure asymptotic coordinated motion, are described and compared. Lyapunov's stability theory-based analysis and numerical simulations in a realistic tridimensional environment show the stability properties of the control approaches

Scalable Schedule-Aware Bundle Routing

This thesis introduces approaches providing scalable delay-/disruption-tolerant routing capabilities in scheduled space topologies. The solution is developed for the requirements derived from use cases built according to predictions for future space topology, like the future Mars communications architecture report from the interagency operations advisory group. A novel routing algorithm is depicted to provide optimized networking performance that discards the scalability issues inherent to state-of-the-art approaches. This thesis also proposes a new recommendation to render volume management concerns generic and easily exchangeable, including a new simple management technique increasing volume awareness accuracy while being adaptable to more particular use cases. Additionally, this thesis introduces a more robust and scalable approach for internetworking between subnetworks to increase the throughput, reduce delays, and ease configuration thanks to its high flexibility.:1 Introduction 1.1 Motivation 1.2 Problem statement 1.3 Objectives 1.4 Outline 2 Requirements 2.1 Use cases 2.2 Requirements 2.2.1 Requirement analysis 2.2.2 Requirements relative to the routing algorithm 2.2.3 Requirements relative to the volume management 2.2.4 Requirements relative to interregional routing 3 Fundamentals 3.1 Delay-/disruption-tolerant networking 3.1.1 Architecture 3.1.2 Opportunistic and deterministic DTNs 3.1.3 DTN routing 3.1.4 Contact plans 3.1.5 Volume management 3.1.6 Regions 3.2 Contact graph routing 3.2.1 A non-replication routing scheme 3.2.2 Route construction 3.2.3 Route selection 3.2.4 Enhancements and main features 3.3 Graph theory and DTN routing 3.3.1 Mapping with DTN objects 3.3.2 Shortest path algorithm 3.3.3 Edge and vertex contraction 3.4 Algorithmic determinism and predictability 4 Preliminary analysis 4.1 Node and contact graphs 4.2 Scenario 4.3 Route construction in ION-CGR 4.4 Alternative route search 4.4.1 Yen’s algorithm scalability 4.4.2 Blocking issues with Yen 4.4.3 Limiting contact approaches 4.5 CGR-multicast and shortest-path tree search 4.6 Volume management 4.6.1 Volume obstruction 4.6.2 Contact sink 4.6.3 Ghost queue 4.6.4 Data rate variations 4.7 Hierarchical interregional routing 4.8 Other potential issues 5 State-of-the-art and related work 5.1 Taxonomy 5.2 Opportunistic and probabilistic approaches 5.2.1 Flooding approaches 5.2.2 PROPHET 5.2.3 MaxProp 5.2.4 Issues 5.3 Deterministic approaches 5.3.1 Movement-aware routing over interplanetary networks 5.3.2 Delay-tolerant link state routing 5.3.3 DTN routing for quasi-deterministic networks 5.3.4 Issues 5.4 CGR variants and enhancements 5.4.1 CGR alternative routing table computation 5.4.2 CGR-multicast 5.4.3 CGR extensions 5.4.4 RUCoP and CGR-hop 5.4.5 Issues 5.5 Interregional routing 5.5.1 Border gateway protocol 5.5.2 Hierarchical interregional routing 5.5.3 Issues 5.6 Further approaches 5.6.1 Machine learning approaches 5.6.2 Tropical geometry 6 Scalable schedule-aware bundle routing 6.1 Overview 6.2 Shortest-path tree routing for space networks 6.2.1 Structure 6.2.2 Tree construction 6.2.3 Tree management 6.2.4 Tree caching 6.3 Contact segmentation 6.3.1 Volume management interface 6.3.2 Simple volume manager 6.3.3 Enhanced volume manager 6.4 Contact passageways 6.4.1 Regional border definition 6.4.2 Virtual nodes 6.4.3 Pathfinding and administration 7 Evaluation 7.1 Methodology 7.1.1 Simulation tools 7.1.2 Simulator extensions 7.1.3 Algorithms and scenarios 7.2 Offline analysis 7.3 Eliminatory processing pressures 7.4 Networking performance 7.4.1 Intraregional unicast routing tests 7.4.2 Intraregional multicast tests 7.4.3 Interregional routing tests 7.4.4 Behavior with congestion 7.5 Requirement fulfillment 8 Summary and Outlook 8.1 Conclusion 8.2 Future works 8.2.1 Next development steps 8.2.2 Contact graph routin

Stratigraphic evolution of the North Levant Platform (Syria) during Aptian to Early Turonian

The Levant margin includes the easternmost part of the Eastern Mediterranean in a region where the oceanic (Tethyan) plates and the Arabian, African and Eurasian crustal plates interact. The tectonic events in relation with these plate deformations resulted in the division of the Levant into several provinces; the Southern, the Middle and the Northern. The studied area forms the Northern part of the Levant Platform. The combination of relative sea changes, tectonics, volcanism and local, regional and global environmental perturbations in the North Levant left imprints on the Aptian - Early Turonian carbonate platform configuration and depositional settings. The latter are reconstructed within a nimproved stratigraphic framework, based on field observations, high resolution biostratigraphy, geochemical analysis, detailed microfacies distribution and sequence stratigraphy. The Aptian Early Turonian succession of the North Levant in the South Palmyrides and Coastal Range of Syria represents two different depositional environments of the intra platform rifting basin (Palmyrides) and passive marginal basin (Coastal Range). Deposition was controlled by terrigenous input and/or nutrition resources, syn-depositional volcanic activity, climatic and sea level change which gives the Aptian and the Albian Early Turonian its characteristic features. A high resolution stratigraphic calibration of the Aptian - Early Turonian strata of the Coastal Range and South Palmyrides are based on the integrated identification of benthonic and planktonic foraminifera, in comparison with carbon isotope signals and (subsurface) logs. The abundant larger benthonic foraminifera in all outcrops of both areas allow to subdivide the Aptian - Early Turonian succession into 7 biozones in the Coastal Range and five in the South Palmyrides. Locally abundant planktonic foraminifera allow the subdivision of the latest Aptian - Cenomanian succession into seven biozones in the South Palmyrides, comparing to seven biozones range from the latest Albian to Early Turonian. Carbon isotope fluctuations record significant perturbations that are well comparable with several global changes of the carbon cycle: OAE1c, OAE1d, LCE I-III, MCE, and OAE2. The carbon isotope record is calibrated by high resolution biostratigraphic data, especially during rising sea levels. The comparison of the sequence stratigraphic interpretation with the major depositional systems shows that the depositional systems correspond very well with deepening-up, maximum flooding surfaces (mfs) and shallowing-up cycles that were applied to support the sequence stratigraphic model. Based on high resolution microfacies and gamma ray logs of five wells, the Aptian-Early Turonian succession was subdivided into eleven 3rd order (Syrian) depositional sequences, bounded by major unconformities. Three Aptian sequences of the Coastal Range and the South Palmyrides with mfs K80, K81S, K82S correlate partly with Arabian mfs (v. Buchem et al., 2012); four Albian sequences of the Coastal Range and two of the South Palmyrides with mfs K83S, K100, K110, K120 and five Cenomanian sequences (mfs K121S, K130, K131 S, K140) are defined

Bohemian graduates in the UK: disciplines and location determinants for entering creative careers

The human capital and regional economic development literature has become increasingly interested in the role of the ‘Bohemian occupations’ on economic growth. Using UK higher education student micro-data, we investigate the characteristics and location determinants of creative (bohemian) graduates. We examine three specific sub-groups: creative arts & design graduates; creative media graduates; other creative graduates. We find these disciplines influence the ability of graduates to enter creative occupations and be successful in the labour market. We also highlight the role of geography, with London and the South East emerging as hubs for studying and providing Bohemian graduates with more labour market opportunities