Lunar Rover Model - Reengineering of an Existing Mobile Platform towards the realization of a Rover Autonomy Testbed

The Automation & Robotics Section of the European Space Agency (ESA) is developing a platform for investigation of different levels of autonomy of planetary rovers. Within this scope a physical flight model is required and the Lunar Rover Model (LRM) is chosen. The LRM is a 4 wheel, medium-scale (120kg) Moon exploration rover breadboard, equipped with a 5- DOF robotic arm. This paper presents the complete refurbishment and motion control redesign. Therefore the rover is equipped with a new distributed motion control architecture based on CANopen. Following the hardware upgrades, a complete dynamic model of the rover is developed in 20sim and algorithms for all the rover locomotion modes are analyzed and implemented. Subsequently all the locomotion control algorithms are ported on the rover and the control performance is evaluated using high accuracy measurement systems

Why do dolphins form mixed-species associations in the Azores ?

Mixed-species associations are temporary associations between individuals of different species that are often observed in birds, primates and cetaceans. They have been interpreted as a strategy to reduce predation risk, enhance foraging success and/or provide a social advantage. In the archipelago of the Azores, four species of dolphins are commonly involved in mixed-species associations: the common dolphin, Delphinus delphis, the bottlenose dolphin, Tursiops truncatus, the striped dolphin, Stenella coeruleoalba, and the spotted dolphin, Stenella frontalis. In order to understand the reasons why dolphins associate, we analysed field data collected since 1999 by research scientists and trained observers placed onboard fishing vessels. In total, 113 mixed-species groups were observed out of 5720 sightings. The temporal distribution, habitat (water depth, distance to the coast), behaviour (i.e. feeding, travelling, socializing), size and composition of mixed-species groups were compared with those of single-species groups. Results did not support the predation avoidance hypothesis and gave little support to the social advantage hypothesis. The foraging advantage hypothesis was the most convincing. However, the benefits of mixed-species associations appeared to depend on the species. Associations were likely to be opportunistic in the larger bottlenose dolphin, while there seemed to be some evolutionary constraints favouring associations in the rarer striped dolphin. Comparison with previous studies suggests that the formation of mixed-species groups depends on several environmental factors, and therefore may constitute an adaptive response

Categorizing click trains to increase taxonomic precision in echolocation click loggers

L.R. and K.J.P. were supported by Marine Scotland Science and the Marine Alliance for Science and Technology for Scotland (MASTS) pooling initiative and their support is gratefully acknowledged. MASTS is funded by the Scottish Funding Council (grant reference HR09011) and contributing institutions.Passive acoustic monitoring is an efficient way to study acoustically active animals but species identification remains a major challenge. C-PODs are popular logging devices that automatically detect odontocete echolocation clicks. However, the accompanying analysis software does not distinguish between delphinid species. Click train features logged by C-PODs were compared to frequency spectra from adjacently deployed continuous recorders. A generalized additive model was then used to categorize C-POD click trains into three groups: broadband click trains, produced by bottlenose dolphin (Tursiops truncatus) or common dolphin (Delphinus delphis), frequency-banded click trains, produced by Risso's (Grampus griseus) or white beaked dolphins (Lagenorhynchus albirostris), and unknown click trains. Incorrect categorization rates for broadband and frequency banded clicks were 0.02 (SD 0.01), but only 30% of the click trains met the categorization threshold. To increase the proportion of categorized click trains, model predictions were pooled within acoustic encounters and a likelihood ratio threshold was used to categorize encounters. This increased the proportion of the click trains meeting either the broadband or frequency banded categorization threshold to 98%. Predicted species distribution at the 30 study sites matched well to visual sighting records from the region.PostprintPeer reviewe

Fabrication of Cement, Polymer, and Metal-Matrix Fibre Composites by Gravity-Assisted Liquid-Binder Infiltration: A Practical Approach

An experimental investigation into the fabrication of cement/polymer/metal fibre composites by gravity-assisted infiltration of the liquid binder is reported. A method was developed consisting of a flow test that was based on columns of woven fibres and an approach that made use of preformed arrays of short fibres to simulate the actual infiltration process. The infiltration characteristics were identified to depend upon the characteristics of the interstice and those of the binders and could be simplified to two key parameters controlling flow: an expression of the fibre interstice and the distance of infiltration. A common relationship was derived between the key parameters. It was concluded that the flow test could be used to assist in the fabrication. A test was also developed that employed a modified binder for the fabrication of fibre reinforced metals. It was concluded that this test was more suitable than others reported in the literature.</jats:p

Greening Infection Prevention and Control: Multifaceted Approaches to a Sustainable Future.

Infection prevention and control, or IP&amp;C, is a critical stakeholder in advancing environmental sustainability in health care. IP&amp;C activities seek to ensure safety of processes in health care from an infection perspective, but how these are performed can drive substantial waste and pollution. There are certain IP&amp;C measures that can, without compromising safety or efficiency, be adapted to more environmentally friendly practices and have a high impact benefit to sustainability without affecting patient outcomes. Moreover, IP&amp;C practice stands to be significantly altered by climate change and pollution. Here, we describe the complex interdependence between sustainability, climate change, and IP&amp;C, and opportunities for IP&amp;C to be at the leading edge of optimizing healthcares environmental footprint

Air Cooling of PV Panels

In the current study fluid flow and heat transfer characteristics over a heated flat plate were investigated in a closed loop wind tunnel. Two free stream flow regimes were considered; Laminar (turbulence intensity, Tu < 0.5%) and Turbulent. For the laminar free stream case, velocities ranging from 4 to 10 m/s that resulted in Reynolds numbers (Re) up to 346,670 were examined. For the turbulent free stream case, Tu=4%, 8% 12%, and Λ=0.015, 0.021 0.030m were set at the leading edge of the 0.34 by 0.52m heated plate. The aluminum flat plate was heated with supplying powers of 52W and 224W. The heated flat plate was positioned at 0° and 20° tilt and the local heat transfer coefficient in terms of Nusselt number (Nu) was determined along the centreline span of the plate in the streamwise coordinate. Effects of Reynolds number, turbulence intensity (Tu) and integral length scale (Λ/x) on Nusselt number were investigated. The convection heat transfer rate increased in the range of 15% ∼ 40% while the turbulent intensity was raised from 4% to 8%. It was observed that the effect of integral length scale (Λ/x) on heat transfer rate is more significant at larger turbulence intensitie

Η σημασία των διακλαδικών ασκήσεων μαζικών απωλειών υγείας

Αυτή η βιβλιογραφική ανασκόπηση εξετάζει τη σημασία των ασκήσεων μαζικών ατυχημάτων (MCΙs) στο πλαίσιο της διαχείρισης και της απόκρισης έκτακτης ανάγκης. Ξεκινά περιγράφοντας την έννοια και τον σκοπό των MCΙs, διερευνώντας πώς είναι αναπόσπαστα στοιχεία για την προετοιμασία και την αποτελεσματική διαχείριση καταστάσεων έκτακτης ανάγκης μεγάλης κλίμακας. Μέσω ανάλυσης θεωρητικών πλαισίων, καθώς και συγκεκριμένων παραδειγμάτων τόσο στην Ελλάδα όσο και στο εξωτερικό, η εργασία υπογραμμίζει τον ρόλο των MCΙ στην ενίσχυση των πρακτικών δεξιοτήτων, των ικανοτήτων λήψης αποφάσεων και της συνεργασίας μεταξύ των υπηρεσιών μεταξύ των πρώτων ανταποκρινόμενων. Επιπλέον, διευκρινίζει τη θετική συσχέτιση μεταξύ της συχνότητας αυτών των ασκήσεων και των βελτιωμένων αποτελεσμάτων απόκρισης στην πραγματική ζωή. Αναφέρονται το Bataclan στη Γαλλία και η άσκηση Πύρανθος στη Μάνη ως παραδείγματα διαχείρισης τέτοιου είδους συμβάντων και προτείνονται συστάσεις για τη μεγιστοποίηση της αποτελεσματικότητας των MCI με βάση αναγνωρισμένες βέλτιστες πρακτικές, συμπεριλαμβανομένης της ενσωμάτωσης νέων τεχνολογιών και προσαρμοστικών στρατηγικών.This bibliographical review, examines the importance of Mass Casualty Exercises (MCIs) in the context of emergency and response management. It begins by describing the concept and purpose of MCIs, exploring the way they constitute an integral part of the preparation and the effective management of large-scale emergencies.Through analysis of theoretical frameworks, as well as specific examples both in Greece and abroad, the paper highlights the role of MCIs in enhancing practical skills, decision-making abilities and inter-agency cooperation among first responders.Furthermore, it clarifies the positive correlation between the frequency of these exercises and improved response outcomes in real life. The Bataclan in France and the Pyranthos exercise in Mani are cited as examples of such event management, and recommendations are proposed to maximize the effectiveness of MCIs based on prime recognized practices, including the integration of new technologies and adaptive strategies

Το Υδρογόνο και η χρήση του ως καύσιμο στις μεταφορές

Εθνικό Μετσόβιο Πολυτεχνείο--Μεταπτυχιακή Εργασία. Διεπιστημονικό-Διατμηματικό Πρόγραμμα Μεταπτυχιακών Σπουδών (Δ.Π.Μ.Σ.) “Συστήματα Αυτοματισμού