Experimental investigation of shallow mixing layers at a river confluence using 3D-PTV

The present study investigates a simplified laboratory model of a river confluence (shallow mixing layer) using 3D-PTV to improve the understanding of the 3-D interaction between the large-scale turbulent motions (Kelvin-Helmholtz instability) and small-scale turbulent motions (Tollmien-Schlichting instability)

Traumatic brain injury in the elderly after a skiing accident: A retrospective cohort study in a level 1 emergency department in Switzerland.

BACKGROUND Skiing is a very popular sport worldwide, with increasing trends over the past decades. This study aimed to evaluate the importance of traumatic brain injury (TBI), especially in the elderly, after a ski accident, and to describe its short-term repercussions. METHODOLOGY Patients were analyzed who were admitted to our neurotrauma center from 2012-2018 after a head trauma while skiing. Three different age groups were differentiated and analyzed for the severity of TBI depending on the initial Glasgow Coma Scale as the primary outcome and as secondary outcomes need and type of surgery, Glasgow Outcome Score, preexisting use of anticoagulant or antiplatelet drugs, time to presentation, and pattern of brain injury. TBI severity was adjusted to the time to initial medical consultation. RESULTS No significant difference in TBI severity was found when comparing the middle (>29-54) and older (≥54) age groups to the reference group <30 years (OR:0.45, p = 0.127; OR:0.46, p = 0.17). Acute subdural hemorrhage was present in 21.2% of the ≥55 group and 14.5% of the 30-54 age group, compared to 12.8% of the youngest group (p = <0.001). Overall, 39.4% of the patients in the ≥55 group and 8.1% of the 30-54 age group presented with chronic subdural hemorrhage, whereas none of the youngest patients did (p = <0.001). CONCLUSION No differences were observed in terms of TBI severity between age groups after acute trauma. Nonetheless, a different pattern of head injury after TBI in older patients was demonstrated. Accordingly, the management differs for these TBIs compared to those of younger patients

Discapacidad visual y orientación urbana. Estudio piloto sobre planos táctiles producidos en Impresión 3D

[EN] This article presents a pilot study conducted in Barcelona with blind and visually-impaired people. The aim was to analyze the use and efficacy of tactile maps produced by means of 3D printing. For this purpose, structured interviews were used, along with direct observation, the creation of cognitive maps and tasks with prototypes. The aim has been to examine the instrumental and communicative value of these products in terms of interpreting, memorizing and understanding a certain urban route, comparing this with experience in situ, focusing on the difficulties faced by the visually disabled when visiting new places. Findings show the utility of this type of technique in aiding visually disabled users to memorize routes. As a limitation, this study shows that tactile maps are not wholly efficient since they require verbal support, which makes it hard for them to be used autonomously.[ES] El trabajo aquí expuesto presenta un estudio piloto llevado a cabo en Barcelona con personas invidentes y deficientes visuales. El objetivo del mismo ha sido analizar el uso y la eficacia de los planos táctiles producidos mediante Impresión en 3D. Para ello se han empleado entrevistas estructuradas, observación directa, realización de mapas cognitivos y tareas con prototipos. De esta manera se ha tratado deprofundizar en elvalor instrumentalycomunicativo de estosproductos a la hora de interpretar, memorizar y comprender un determinado recorrido urbano, contrastándolo con la experiencia in situ, atendiendo a las dificultades que este tipo de personas presentan a la hora de visitar nuevos lugares. Los resultados obtenidos demuestran la utilidad de este tipo de técnica para memorizar recorridos por parte de este tipo de usuarios. Como limitación, el estudio muestra que los planos táctiles no resultan del todo eficientes pues precisan de apoyo verbal, hecho que dificulta su uso autónomo.This research has been funded by the Spanish Ministry of Science and Innovation as part of the National Fundamental Research Programme, the National R&D/Innovation Plan, within the project “Study and design of orientation elements, communication support and other accessories to improve accessibility in different spheres of interpreting natural and/or built heritage’ (DPI2008-03981/DPI). The authors would also like particularly to thank the following for their selfless collaboration: the ONCE Educational Resources Centre in Barcelona and staff from the Disabled Service Programme at the Universitat Politècnica de Catalunya. The study was also carried out as part of the Research Staff Mobility Programme at Universitat Jaume I (E-2010-32) funded by the Caixa Castelló-Bancaixa Foundation.Gual Ortí, J.; Puyuelo Cazorla, M.; Lloveras, J.; Merino Sanjuan, L. (2012). Visual Impairment and urban orientation. Pilot study with tactile maps produced through 3D Printing. Psyecology. 3(2):239-250. https://doi.org/10.1174/217119712800337747S2392503

A cooperative game approach to a production planning problem

This paper deals with a production planning problem formulated as a Mixed Integer Linear Programming (MILP) model that has a competition component, given that the manufacturers are willing to produce as much products as they can in order to fulfil the market’s needs. This corresponds to a typical game theoretic problem applied to the productive sector, where a global optimization problem involves production planning in order to maximize the utilities for the different firms that manufacture the same type of products and compete in the market. This problem has been approached as a cooperative game, which involves a possible cooperation scheme among the manufacturers. The general problem was approached by Owen (1995) as the “production game” and the core was considered. This paper identifies the cooperative game theoretic model for the production planning MILP optimization problem and Shapley Value was chosen as the solution approach. The results obtained indicate the importance of cooperating among competitors. Moreover, this leads to economic strategies for small manufacturing companies that wish to survive in a competitive environment

Electrochemical Activation of Ni Catalysts with Potassium Ionic Conductors for CO2 Hydrogenation

Three different kind of Ni-based catalysts were prepared on a K-β″Al2O3 solid electrolyte by combining the annealing of an organometallic paste and the addition of a catalyst powder. The different catalysts films were tested in the CO2 hydrogenation reaction under electrochemical promotion by K+ ions, and were characterized by XRD and SEM. The catalyst film derived from the addition of an α-Al2O3 powder to the Ni catalyst ink presented the highest catalytic activity as a result of the increase in Ni catalyst film porosity. The influence of the applied potential and other operation variables were evaluated on the Ni catalytic activity and selectivity. Hence, the CO production rate was enhanced either by decreasing the applied potential (with the consequent supply of K+ ions to the catalyst surface) or by increasing the CO2 (electron acceptor) feed concentration. On the other hand, CH4 production rate was favoured at positive potentials (removing K+ from the catalyst surface) or by increasing the H2 (electron donor) feed concentration. The global CO2 consumption rate increased upon negative polarization in all experiments and the electrochemical promotion of catalysis effect showed to be reversible and reproducible. Hence, the electrochemical promotion phenomena demonstrated to be a very useful technique to in situ modify and control the catalytic activity and selectivity of a non-noble metal such as Ni for the production of CH4 or syngas via CO2 valorization.Es la versión preprint del artículo. Se puede consultar la versión final en https://doi.org/10.1007/s11244-015-0488-

Selective effects of small barriers on river‐resident fish

Habitat fragmentation is a principal threat to biodiversity and artificial river barriers are a leading cause of the global decline in freshwater biota. Although the impact of barriers on diadromous fish is well established, impacts on river-resident fish communities remain unclear, especially for low-head barriers.We examined the movement of five contrasting freshwater fish (topmouth gudgeon, European minnow, stone loach, bullhead and brown trout) in an experimental cascade mesocosm with seven pools separated by small vertical barriers.Passage rates differed significantly among species and increased with body size and sustained swimming speed (Usus), ranging from an average of 0.2 passes/hr in topmouth gudgeon to 3.4 passes/hr in brown trout. A random-walk simulation indicated that barriers can result in net downstream movement and shifts in community composition.Passage rates in brown trout were leptokurtic, that is, most individuals were relatively sedentary while a small proportion showed frequent movements. Upstream passage rates of brown trout increased with body length and boldness while fish with lower aerobic scope tended to move downstream. Passage rates showed significant individual repeatability in brown trout, independent of body size, indicating the potential for in-stream barriers to exert selective effects on fish populations.Our results show that barrier effects can be more complex than simply blocking fish passage, and that river-resident fish can be impacted even by very small barriers. We show that fish passage depends on a wide range of morphological, physiological and behavioural drivers, and that barriers can exert selective effects on these traits and cause shifts in community composition.Policy implications. Barrier mitigation measures need to embrace interspecific and intraspecific variation in fish passage to avoid inadvertent artificial selection on fish communities. Given the high abundance of low-head structures in river systems worldwide, a paradigm shift is needed to recognise the subtle impacts of small barriers on freshwater biodiversity. Removal of small barriers or nature-like fishways should allow better passage of the wider fish community compared to widely used salmonid-centric fish passage options

Temporal and spatial instability in neutral and adaptive (MHC) genetic variation in marginal salmon populations

The role of marginal populations for the long-term maintenance of species’ genetic diversity and evolutionary potential is particularly timely in view of the range shifts caused by climate change. The Centre-Periphery hypothesis predicts that marginal populations should bear reduced genetic diversity and have low evolutionary potential. We analysed temporal stability at neutral microsatellite and adaptive MHC genetic variation over five decades in four marginal Atlantic salmon populations located at the southern limit of the species’ distribution with a complicated demographic history, which includes stocking with foreign and native salmon for at least 2 decades. We found a temporal increase in neutral genetic variation, as well as temporal instability in population structuring, highlighting the importance of temporal analyses in studies that examine the genetic diversity of peripheral populations at the margins of the species’ range, particularly in face of climate change

Mechanical and structural assessment of laboratory- and field-compacted asphalt mixtures

Compaction forms an integral part in the formation of the aggregate orientation and structure of an asphalt mixture and therefore has a profound influence on its final volumetric and mechanical performance. This article describes the influence of various forms of laboratory (gyratory, vibratory and slab-roller) and field compaction on the internal structure of asphalt specimens and subsequently on their mechanical properties, particularly stiffness and permanent deformation. A 2D image capturing and image analysis system has been used together with alternative specimen sizes and orientations to quantify the internal aggregate structure (orientation and segregation) for a range of typically used continuously graded asphalt mixtures. The results show that in terms of aggregate orientation, slab-compacted specimens tend to mimic field compaction better than gyratory and vibratory compaction. The mechanical properties of slab-compacted specimens also tend to be closer to that of field cores. However, the results also show that through careful selection of specimen size, specimen orientation and compaction variables, even mould-based compaction methods can be utilised with particular asphalt mixtures to represent field-compacted asphalt mixtures

Performance evaluation of a hybrid vehicle and sensor network to prevent traffic accidents

In recent years, wireless networks have become a widespread communication technology as well as a research challenge. Many contributions have been made on ad hoc networks, such as wireless sensor networks (WSNs) and vehicular ad hoc networks (VANETs). Recently, the number of cars on our streets, roads, and highways has been increasing, giving rise to a great interest in vehicular communication technologies. This paper presents an hybrid sensor and vehicular network (HSVN) platform, as well as the description and evaluation of a communication protocol between VANETs and WSNs using a network simulator for its evaluation

Metrological framework for passive radiative cooling technologies and development setups for reproducible in-field performance testing

Almost 20 % of the global electricity consumption is caused by cooling systems. As the demand for cooling is expected to grow tenfold by 2050, improving the efficiency of cooling systems plays a critical role in addressing the global climate challenge. Passive Radiative Cooling (PRC) materials, which can dissipate heat into the surrounding as thermal radiation (especially through the atmospheric infrared window between 8 µm and 13 µm) have recently emerged. Hence, the project PaRaMetriC (Metrological Framework for Passive Radiative Cooling Technologies) aims to develop a comprehensive metrological framework with standardized performance indicators and testing protocols to enable comparable evaluation of their cooling performance on-site and the determination of potential energy savings that could derive from the deployment of such technologies. One work package within this project deals with the design of a testing setup and the development of a protocol for determining the figures of merit of candidate PRC materials by in-field measurements with a relative uncertainty below 10 %. For this purpose, on-site prototype setups are planned to be realized in different climatic regions, e.g. Barcelona (maritime Mediterranean climate), Madrid (continental Mediterranean climate), Torino (warm temperate climate) and Würzburg (moderate temperate climate), in order to cover a wide range of environmental conditions. With these prototype setups, measurements will be performed on candidate benchmark materials. Additionally, the environmental and atmospheric conditions (temperature, solar irradiance, humidity, wind speed, etc.) will be monitored during the measurements using appropriate sensors. Up to now, the design work has been started. This presentation gives an overview of the PaRaMetriC project and provides an outlook on the aimed future activities regarding the setup for in-field measurements, including the configuration of the setup (thermal insulation, thermal load, etc.), the selection of appropriate sensors and the implementation of PRC materials. Furthermore, previous work will be presented. So far, first PRC materials with high solar reflectance and high thermal emittance have been prepared. Beside the infrared-optical properties, the thermal conductivity of the prepared layers has also been measured. At these samples, the derived surface temperature has been measured for sky-facing surfaces in dependence on the surrounding conditions. Together with measurements on reference materials, the correlation of the surface temperature with the solar reflectance index (SRI) has been investigated. The SRI value has been determined by measurements of the solar reflectance and thermal emittance of the prepared PRC materials according to ASTM E 1980 - 11. As a preliminary result, a temperature drop below ambient air temperature has been recorded for some prepared PRC materials even during the day in sunshine