Vanadium redox flow batteries: Potentials and challenges of an emerging storage technology

open4noIn this paper an overview of Vanadium Redox Flow Battery technologies, architectures, applications and power electronic interfaces is given. These systems show promising features for energy storage in smart grid applications, where the intermittent power produced by renewable sources must meet strict load requests and economical opportunities. This paper reviews the vanadium-based technology for redox flow batteries and highlights its strengths and weaknesses, outlining the research lines that aim at taking it to full commercial success.openSpagnuolo, Giovanni, Guarnieri, Massimo; Mattavelli, Paolo; Petrone, Giovanni;Guarnieri, Massimo; Mattavelli, Paolo; Petrone, Giovanni; Spagnuolo, Giovann

Robust Processing of Natural Language

Previous approaches to robustness in natural language processing usually treat deviant input by relaxing grammatical constraints whenever a successful analysis cannot be provided by ``normal'' means. This schema implies, that error detection always comes prior to error handling, a behaviour which hardly can compete with its human model, where many erroneous situations are treated without even noticing them. The paper analyses the necessary preconditions for achieving a higher degree of robustness in natural language processing and suggests a quite different approach based on a procedure for structural disambiguation. It not only offers the possibility to cope with robustness issues in a more natural way but eventually might be suited to accommodate quite different aspects of robust behaviour within a single framework.Comment: 16 pages, LaTeX, uses pstricks.sty, pstricks.tex, pstricks.pro, pst-node.sty, pst-node.tex, pst-node.pro. To appear in: Proc. KI-95, 19th German Conference on Artificial Intelligence, Bielefeld (Germany), Lecture Notes in Computer Science, Springer 199

Numerical Modelling for Hydrodynamic Impact and Power Assessments of Tidal Current Turbine Arrays

Channel constrictions in which strong currents are mainly driven by tidal processes represent sites with high potential for harvesting renewable and predictable tidal stream energy. Tidal Current Turbines (TCTs) deployed in arrays appear to be the most promising solution to efficiently capturing this carbon neutral energy resource. However to ensure the sustainable character of such projects, the balance between power extraction maximization and environmental impact minimization must be found so that device layout optimization takes into account environmental considerations. This is particularly appropriate since both resource and impact assessments go intrinsically hand in hand. The present method proposes the use and adaptation of ocean circulation models as an assessment tool framework for tidal current turbine (TCT) array-layout optimization. By adapting both momentum and turbulence transport equations of an existing model, the present TCT representation method is proposed to extend the actuator disc concept to 3-D large scale ocean circulation models. Through the reproduction of physical experiments to reasonable accuracy, grid and time dependency tests and an up-scaling exercise, this method has shown its numerical validity as well as its ability to simulate accurately both momentum and turbulent turbine-induced perturbations in the wake. These capabilities are demonstrated for standalone devices and device arrays, and are achieved with a relatively short period of computation time. Consequently the present TCT representation method is a very promising basis for the development of a TCT array layout optimization tool. By applying this TCT representation method to realistic cases, its capability is demonstrated for power capture assessment and prediction of hydrodynamic interactions as would be required during the layout deployment optimization process. Tidal energy has seen considerable development over the last decade and the first commercial deployments are likely to take place within the next 5 years. It is hoped that this new tool and the numerical approaches described herein will contribute to the development of TCT array power plants around the world.Great Western Research and International Power Marine Developments Limite

Cooperative Traffic Control Solution for Vehicle Transition from Autonomous to Manual Mode exploiting Cellular Vehicle-to-Everything (C-V2X) Technology

Nowadays, automated vehicles represent a promising technology to face the stringent requirements for safety and traffic efficiency in the automotive environment. Driving responsibilities will be gradually addressed to the machine, and the role of human pilots will be progressively reduced to passengers. The interaction between passengers and the automated system will create different risks that have not been considered in the past. In particular, the transition between autonomous and manual mode is understood as a risky situation. During the transition, the driver manifests driving irregularities and loss of situation awareness that may endanger himself and other participants on the road. Hence, the vehicle transitioning needs a higher quantity of space around it to be considered safe. However, no effective solution has been developed yet. This thesis aims to design a cooperative traffic control solution that will manage the movements of the group of vehicles to increase the free space around the one transitioning. It will exploit another tool that will play a fundamental role in the future of the automotive industry: connected vehicles technology. C-V2X technology will create a medium for vehicles to exchange information and cooperate. A controller managing the cooperation between vehicles has been developed to help a smooth and safe vehicle repositioning. The controller will be positioned in a centralized computing facility and it will communicate with all the vehicles. The controller defines rules to move vehicles together and enlarge the free space around the vehicle transitioning without collisions. The rules are modeled by a spring-mass-damper system, that can be exploited to control the longitudinal behavior of automated vehicles. In particular, the spring-mass-damper system can manage smooth migration between vehicle dispositions without oscillations. A computer simulation is used to test the performance of the proposed traffic control system. The simulation environment is constituted by three main components: traffic flow, controller and communication network. It has been tested with the software VEINS, which provides interaction between a network simulator (OMNeT++) and a traffic simulator (SUMO). The traffic flow represents the interactions between vehicles. The controller analyzes the data and sends control messages to all vehicles. The communication network will share the data concerning vehicles’ position and speed and control messages. The proposed cooperative vehicle control system demonstrated to reduce the risks of the transition with the smooth motion of vehicles. The controller is able to achieve the safety requirements without reducing the level of comfortability of vehicles’ passengers

Effects of acute and chronic restraint stress during adolescence on endocannabinoid-mediated synaptic plasticity in the mouse hippocampal dentate gyrus.

160 p.Our society lives embedded in stress. This causes numerous environmental factors that precipitate and exacerbate psychiatric disorders, such as anxiety and depression. In all organisms, stress is recognized as an adaptive response and is essential for survival to re-establish homeostasis. The brain is the most sensitive organ to stress and responsible for generating an adaptation to stressors, both social and physical. In mammals, multiple brain areas, such as the hippocampus, amygdala, prefrontal cortex and hypothalamus are activated in response to the threat of homeostasis disruption. In particular, the hippocampus is critically involved in many forms of learning and memory, as well as emotional processing and stress. Despite adolescence being a vital stage where numerous changes occur, research on changes in stress-related synaptic plasticity and the brain has been focused more on childhood and adulthood. The endocannabinoid (eCB) system is widely distributed in the central nervous system and participates in many brain functions. To better understand the role of the eCB system in the context of anxiety and how to cope stress is necessary an integrated view of the endocannabinoid-mediated control in brain regions involved in stress processing and regulation. In this Doctoral Thesis, adolescent Swiss male mice were used to investigate the localization and function of the CB1 receptor at the excitatory medial perforant path (MPP) synapses in the dentate molecular layer of the hippocampus in control, acute and chronic restraint stress condition. The rational behind is that these synapses show high efficiency in neuronal activation and contribute to the excitatory tri-synaptic circuit related to learning and memory in the hippocampus. Furthermore, restraint stress damages the entorhinal cortex and dentate gyrus affecting the entorhino-dentate (perforant) pathway. We studied in the Thesis the effect of acute and chronic restraint stress to adolescent mice on synaptic transmission and in particular on CB1 receptor dependent long-term depression at the excitatory MPP-granule cell synapses

Effects of acute and chronic restraint stress during adolescence on endocannabinoid-mediated synaptic plasticity in the mouse hippocampal dentate gyrus.

160 p.Our society lives embedded in stress. This causes numerous environmental factors that precipitate and exacerbate psychiatric disorders, such as anxiety and depression. In all organisms, stress is recognized as an adaptive response and is essential for survival to re-establish homeostasis. The brain is the most sensitive organ to stress and responsible for generating an adaptation to stressors, both social and physical. In mammals, multiple brain areas, such as the hippocampus, amygdala, prefrontal cortex and hypothalamus are activated in response to the threat of homeostasis disruption. In particular, the hippocampus is critically involved in many forms of learning and memory, as well as emotional processing and stress. Despite adolescence being a vital stage where numerous changes occur, research on changes in stress-related synaptic plasticity and the brain has been focused more on childhood and adulthood. The endocannabinoid (eCB) system is widely distributed in the central nervous system and participates in many brain functions. To better understand the role of the eCB system in the context of anxiety and how to cope stress is necessary an integrated view of the endocannabinoid-mediated control in brain regions involved in stress processing and regulation. In this Doctoral Thesis, adolescent Swiss male mice were used to investigate the localization and function of the CB1 receptor at the excitatory medial perforant path (MPP) synapses in the dentate molecular layer of the hippocampus in control, acute and chronic restraint stress condition. The rational behind is that these synapses show high efficiency in neuronal activation and contribute to the excitatory tri-synaptic circuit related to learning and memory in the hippocampus. Furthermore, restraint stress damages the entorhinal cortex and dentate gyrus affecting the entorhino-dentate (perforant) pathway. We studied in the Thesis the effect of acute and chronic restraint stress to adolescent mice on synaptic transmission and in particular on CB1 receptor dependent long-term depression at the excitatory MPP-granule cell synapses

A Unified Model for Context-Sensitive Program Analyses: The Blind Men and the Elephant

Context-sensitive methods of program analysis increase the precision of interprocedural analysis by achieving the effect of call inlining. These methods have been defined using different formalisms and hence appear as algorithms that are very different from each other. Some methods traverse a call graph top-down whereas some others traverse it bottom-up first and then top-down. Some define contexts explicitly whereas some do not. Some of them directly compute data flow values while some first compute summary functions and then use them to compute data flow values. Further, different methods place different kinds of restrictions on the data flow frameworks supported by them. As a consequence, it is difficult to compare the ideas behind these methods in spite of the fact that they solve essentially the same problem. We argue that these incomparable views are similar to those of blind men describing an elephant called context sensitivity, and make it difficult for a non-expert reader to form a coherent picture of context-sensitive data flow analysis. We bring out this whole-elephant view of context sensitivity in program analysis by proposing a unified model of context sensitivity which provides a clean separation between computation of contexts and computation of data flow values. Our model captures the essence of context sensitivity and defines simple soundness and precision criteria for context-sensitive methods. It facilitates declarative specifications of context-sensitive methods, insightful comparisons between them, and reasoning about their soundness and precision. We demonstrate this by instantiating our model to many known context-sensitive methods