Robustness of the European power grids under intentional attack

The power grid defines one of the most important technological networks of our times and sustains our complex society. It has evolved for more than a century into an extremely huge and seemingly robust and well understood system. But it becomes extremely fragile as well, when unexpected, usually minimal, failures turn into unknown dynamical behaviours leading, for example, to sudden and massive blackouts. Here we explore the fragility of the European power grid under the effect of selective node removal. A mean field analysis of fragility against attacks is presented together with the observed patterns. Deviations from the theoretical conditions for network percolation (and fragmentation) under attacks are analysed and correlated with non topological reliability measures.Comment: 7 pages, 4 figure

Effective Building Modelling for Energy Performance Contracting

Energy Performance Contracts (EPC) are contractual agreements between beneficiaries and energy service providers, where budgets are established in relation to a determined level of energy performance. Hence, the problem of forecasting the energy performance of buildings in the EPC tendering phase becomes relevant for the reliability of the overall contract. Unfortunately, fuzziness and incompleteness often characterize the technical information supporting EPC call for tenders. Furthermore, buildings that are the subjects of EPCs are normally quite complex public buildings (hospitals, schools, etc.) usually relatively old and not technically well known. Gathering information about such buildings is a time consuming and expensive process within the usually short time frame of EPC call for tenders. This paper investigates the application of Grey-Box modelling to the energy performance forecast of complex buildings, in perfectly and poorly informed operational cases. The proposed methodology offers a potential solution to the EPC operational requirements since it requires a substantially reduced parameter set. Results show that the proposed Grey-Box modelling can be used to arrange a calibration set-up with good forecasting performance. Furthermore, Grey-Box modelling allows an effective management of the information uncertainty usually present in the EPC context

Infection risk of Monilinia fructicola on stone fruit during cold storage and immersion in the dump tank

Monilinia spp. is the main pathogen responsible for postharvest losses of stone fruit. Several studies have examined the conditions for Monilinia spp. infection in the field, but very limited information is available about postharvest. Storing fruit for 1 day in the cold room or dumping fruit in a water tank are the most common handling operations during the postharvest of fruit. Then, the aim of this study was to investigate the risk of Monilinia fructicola infection for two peach and one nectarine cultivars during cold storage and water dump operations. A new methodology was performed using a dry inoculum of M. fructicola. A set of fruit was used as control to demonstrated that at 20 °C 60% relative humidity (RH) was not able to infect fruit, however, the disease was developed when was already infected. In addition, M. fructicola was able to infect and develop disease in fruit at 20 °C 100 RH. The storage of fruit with the presence of M. fructicola conidia on their surface for up to 30 days at 0 °C 100% RH or 4 °C 100% RH did not suppose an important risk of infection since only 3.3 and 3.8%, respectively of fruit were already infected. Overall, all treatments tested with the water dump operation gave optimal conditions to M. fructicola to infect fruit when it was superficially dry inoculated or it was immersed with water contaminated with conidia, increasing the need for water disinfection. In addition, when fruit was immersed in water free from M. fructicola conidia, the postharvest operation gave optimal conditions to develop infections already produced.info:eu-repo/semantics/acceptedVersio

Results and insight gained from applying the EnergyCat energy-saving serious game in UK social housing

Concerns about climate change associated with the combustion of fossil fuels urge a call for widespread reductions in household energy use. Determining means of achieving this is a key challenge faced by environmental scientists. The current research presents insights gained from a 12-month empirical trial of new serious game for energy, ‘EnergyCat’; which was designed to encourage household energy reductions in the UK social housing sector. Effects of gameplay on consumption behaviours and energy awareness were explored using 82 UK social housing households (versus a no-game control). Results indicated the intervention did not lead to any substantive changes in awareness or consumption practices. However, post-intervention feedback highlighted several issues in terms of game design and usability that may explain why the game failed to change behaviour in this instance. We provide a framework of suggestions as to how the game design process could be improved in order to engage residents in future, including use of adaptive fonts for older residents, and provision of clearer instructions on gameplay objectives at the outset. In addition, researchers should ensure close collaboration is maintained with residents throughout the design process in future efforts, in order to maximise likelihood of ongoing engagement from this population

Guidelines for oral assessment

En este documento se presentan los lineamientos y teoría para la implementación de un sistema de evaluación oral en el Centro de Idiomas de la Universidad Eafit. El texto desarrolla tres temas principales: 1) el enfoque comunicativo para la enseñanza y la evaluación ; 2) la planeación de la evaluación; y 3) el uso de las herramientas de evaluación.This document aims at offering teachers a framework for assessing oral language and some guidelines that will foster the implementation and practice of a homogeneous oral assessment system (OAS) at the EAFIT University Language Center. The document deals with three main topics, namely (1) Communicative Approach to Teaching and Assessment; (2) Planning for Assessment; and (3) Using the Oral Assessment Rubric

Rotating Black Holes at Future Colliders. III. Determination of Black Hole Evolution

TeV scale gravity scenario predicts that the black hole production dominates over all other interactions above the scale and that the Large Hadron Collider will be a black hole factory. Such higher dimensional black holes mainly decay into the standard model fields via the Hawking radiation whose spectrum can be computed from the greybody factor. Here we complete the series of our work by showing the greybody factors and the resultant spectra for the brane localized spinor and vector field emissions for arbitrary frequencies. Combining these results with the previous works, we determine the complete radiation spectra and the subsequent time evolution of the black hole. We find that, for a typical event, well more than half a black hole mass is emitted when the hole is still highly rotating, confirming our previous claim that it is important to take into account the angular momentum of black holes.Comment: typoes in eqs(82)-(84) corrected; version to appear in Phys. Rev. D; references and a footnote added; same manuscript with high resolution embedded figures available on http://www.gakushuin.ac.jp/univ/sci/phys/ida/paper

Efficacy of environmental friendly disinfectants against the major postharvest pathogens of stone fruits on plastic and wood surfaces

Disinfection of surface facilities during postharvest handling operation is an important practice to avoid secondary fruit infections at stone fruit packinghouses. The aim of this work was to evaluate the effect of six environmental friendly disinfectants against Monilinia fructicola, Penicillium expansum, Rhizopus spp., and Alternaria spp. on plastic and wood surfaces. Hydrogen peroxide, peracetic acid, sodium hypochlorite, Mico-E-pro®, Proallium FRD-N®, and DMC Clean-CNS® were used as the disinfectants. Untreated and surfaces treated with water were used as controls. Plastic and wood surfaces were sampled with Rodac plates at 2 and 24 h after treatments and the number of colonies were counted. In general, all disinfectants reduce the number of viable conidia from all studied surfaces. Hydrogen peroxide used in a concentration of 150 mg L−1 was the less effective disinfectant in all studied pathogens. The commercial product Mico-E-pro® composed of oregano, onion, and orange extract at a dose of 10 mg L−1 was the most effective disinfectant. Rhizopus spp. was the pathogen more resistant to the disinfectants followed by P. expansum, M. fructicola, and Alternaria spp. Water decreased the number of conidia adhered to the surface. In addition, the untreated control showed substantial conidia reduction after 24 h of artificial inoculation.info:eu-repo/semantics/acceptedVersio

Comparative analysis of cold ironing rules

Postprint (published version

An explicit total Lagrangian Fragile Points Method for finite deformation of hyperelastic materials

This research explored a novel explicit total Lagrangian Fragile Points Method (FPM) for finite deformation of hyperelastic materials. In contrast to mesh-based methods, where mesh distortion may pose numerical challenges, meshless methods are more suitable for large deformation modelling since they use enriched shape functions for the approximation of displacements. However, this comes at the expense of extra computational overhead and higher-order quadrature is required to obtain accurate results. In this work, the novel meshless method FPM was used to derive an explicit total Lagrangian algorithm for finite deformation. FPM uses simple one-point integration for exact integration of the Galerkin weak form since it employs simple discontinuous polynomials as trial and test functions, leading to accurate results even with single-point quadrature. The proposed method was evaluated by comparing it with FEM in several case studies considering both the extension and compression of a hyperelastic material. It was demonstrated that FPM maintained good accuracy even for large deformations where FEM failed to converge