Brayton-Moser Equations and New Passivity Properties for Nonlinear Electro-Mechanical Systems

This paper presents an alternative framework for a practically relevant class of nonlinear electro-mechanical systems. The formalism is based on a generalization of Brayton and Moser’s mixed-potential function. Instead of focusing on the usual energy-balance, the models are constructed using the power flowing through the system. The main objective is to put forth the mixed-potential function as a new building block for modeling, analysis and controller design purposes for electro-mechanical systems

Modelling tropical-like cyclones (medicanes) over the Mediterranean Sea in a regional climate model ensemble: impact of ocean-atmosphere coupling and increased resolution

Medicanes are cyclones over the Mediterranean Sea having a tropical structure and a rather small size, for which the sea-atmosphere interaction plays a fundamental role. High resolution and ocean-atmosphere coupled RCM simulations performed in MedCORDEX and EURO-CORDEX projects are used to analyze the ability of RCMs to represent the observed characteristics of medicanes, and the impact of increasing resolution and using air-sea coupling on its simulation. An observational database based on satellite images combined with very high resolution simulations (Miglietta et al. 2013) is used as the reference for evaluating the simulations. The simulated medicanes do not coincide in general with the observed cases, so that the evaluation should be done in a statistical sense. The spatial distribution of medicanes is generally well simulated, while the monthly distribution reveals the difficulty of simulating the first medicanes appearing in September after the summer minimum. Large differences are found among models, supporting the use of multi-model ensembles. Interesting trade-offs are found for some models, as better values for intensity are associated to worse frequency values in one model, or relatively good values of frequency and intensity are obtained at the expense of a damped air-sea interaction in a model with spectral nudging. High resolution has a strong and positive impact on the frequency of simulated medicanes, while the effect on its intensity is less clear. Air-sea coupling reduces the medicane frequency, as could be expected due to a negative intensity feedback that is known for tropical cyclones. A preliminary analysis indicates that this feedback could depend on the oceanic mixed layer depth, increasing the interest of applying ocean-atmosphere coupled RCMs

Bringing Research into the Classroom – The Citizen Science approach in schools.

The way science is approached in the classroom can be instrumental in dispelling negative stereotypes about science and scientific research in future generations. The present report looks at the Citizen Science approach as an opportunity to connect schools with the world of research to foster a better command of scientific processes in the young, raise their awareness of current issues faced in certain sectors and geographical regions, and help them make sense of the surrounding world. The purpose of this report is to provide a baseline for understanding the key conditions of successfully implementing citizen science activities in schools. This report is based on three main sources of information: (1) review of recent literature on Citizen Science and its applications in schools; (2) a collection of citizen science case studies selected by educational organisations in four countries (Belgium, Greece, Poland and Spain) and from the Scientix repository of resources; and (3) the discussions between project managers, project representatives and science educators participating in the 14th Science Projects Networking Event (SPNE14), organisedbyScientixwiththecollaborationoffour other organisations and projects – GFOSS, Jet Propulsion Theatre, EDU-ARCTIC and ERIS. The report includes three main sections. The first explores the current literature on citizen science, guided by three main questions: (1) how do we define citizen science, (2) what are the main actors involved in citizen science projects and how do they contribute, and (3) what are the particularities of citizen science activities run in the context of formal education. The second section illustrates 20 citizen science projects, indicating the target audiences and main areas of research covered, as well as a description of the activities, outlining which part of the scientific method is carried out by volunteers, and, when such information is available, descriptions of the roles and interactions between the researchers and citizen scientists. Finally, the third section presents a discussion on the case studies included in the report, with a focus on the main challenges and opportunities of bringing citizen science in schools. The main challenge of running citizen science activities in school which transpired from the literature review and the review of the case studies is the issue of balancing research and educational outcomes. For educational outcomes to be achieved, citizen science projects in schools need to go beyond engaging pupils only in data collection and simple analysis, and look to involving them in meaningful research practices, which will give them the opportunity to develop scientific inquiry skills. On the same line, if genuine science outcomes are to be met, the ‘novice’ scientists (teachers and their students) need to interact with the researchers in order to be exposed to the requirements of the scientific method, and be supported in implementing it. Research suggests that carefully designed projects, created in dialogue between schools (teachers) and researchers which take into consideration the needs and constraints of both groups can successfully achieve both goals.status: Published onlin