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Recycling of material at subduction zones has fundamental implications for melt composition and mantle rheology. Ocean island basalts (OIBs) sample parts of the mantle from variable depths that have been diversely affected by subduction zone processes and materials, including the subducted slab, metasomatising melts and fluids. Resultant geochemical differences are preserved at a variety of scales from melt inclusions to whole rocks, from individual islands to chains of islands. Here we examine a global dataset of ocean island basalt compositions with a view to understanding the connection between silica-saturation, olivine compositions, and halogens in glass and olivine-hosted melt inclusions to reveal information regarding the mantle sources of intraplate magmatism. We find that minor elements incorporated into olivine, although informative, cannot unambiguously discriminate between different source contributions, but indicate that none of the OIB analysed here are derived solely from dry peridotite melting. Nor can differences in lithospheric thickness explain trace element variability in olivine between different ocean islands. We present new halogen (F, Cl, Br/Cl, I/Cl) data along with incompatible trace element data for the global array and encourage measurement of fluorine along with heavier halogens to obtain better insight into halogen cycling. We suggest that Ti-rich silica-undersaturated melts require a contribution from carbonated lithosphere, either peridotite or eclogite and are an important component sampled by ocean island basalts, together with altered oceanic crust. These results provide new insights into our understanding of mantle-scale geochemical cycles, and also lead to the potential for the mantle transition zone as an underestimated source for observed volatile and trace-element enrichment in ocean island basalts.

In January 2019, the Netherlands Scientific Council for Government Policy published the report Money and Debt (‘Geld en Schuld’). This report explains how money creation works, describes the main problems of the current monetary and financial system and discusses several reform options. In this article we present the report’s main analysis and conclusions. We focus in particular on our recommendation to facilitate a bank that deals exclusively with payment and savings services. IN BRIEF ● The Dutch financial system is characterized by exceptionally high private debt levels and an imbalance between public and private interests. ● To address these problems, our financial system needs to change significantly. In particular, greater diversity in the banking sector is essential. ● A payment bank can contribute to diversity and, as such, be part of the solution.

We have determined experimentally the hydrous phase relations and trace element partitioning behaviour of ocean floor basalt protoliths at pressures and temperatures (3 GPa, 750-1000°C) relevant to melting in subduction zones. To avoid potential complexities associated with trace element doping of starting materials we have used natural, pristine mid-ocean ridge basalt (MORB from Kolbeinsey Ridge) and altered oceanic crust (AOC from Deep Sea Drilling Project leg 46, ∼20°N Atlantic). Approximately 15 wt % water was added to starting materials to simulate fluid fluxing from dehydrating serpentinite underlying the oceanic crust. The vapour-saturated solidus is sensitive to basalt K2O content, decreasing from 825 ± 25°C in MORB (∼0·04 wt % K2O) to ≈750°C in AOC (∼0·25 wt % K2O). Textural evidence indicates that near-solidus fluids are sub-critical in nature. The residual solid assemblage in both MORB and AOC experiments is dominated by garnet and clinopyroxene, with accessory kyanite, epidote, Fe-Ti oxide and rutile (plus quartz-coesite, phengite and apatite below the solidus). Trace element analyses of quenched silica-rich melts show a strong temperature dependence of key trace elements. In contrast to the trace element-doped starting materials of previous studies, we do not observe residual allanite. Instead, abundant residual epidote provides the host for thorium and light rare earth elements (LREE), preventing LREE from being released (ΣLREE 1500 and La/SmPUM (where PUM indicates primitive upper mantle) ∼1, most closely matching the geochemical signal of arc lavas worldwide, were generated from AOC at 800-850°C

With the progress made in active exploration, the robots of the Joint Rescue Forces are capable of making deliberative decisions about the distribution of exploration locations over the team. Experiments have been done which include information exchange between team-members at rendez-vous points and dynamic role switching between relays and explorers. In the previous competition exploration was demonstrated with large robots with advanced mobility, such as the Kenaf and the AirRobot. This year our mapping algorithms are extended to be able to explore with the smaller AR.Drone, a flying robot used in the International Micro Air Vehicle competition. Further, progress will be demonstrated in automatic victim detection.

We present the MeerLICHT and BlackGEM telescopes, which are wide-field optical telescopes that are currently being built to study transient phenomena, gravitational wave counterparts and variable stars. The telescopes have 65 cm primary mirrors and a 2.7 square degree field-of-view. The MeerLICHT and BlackGEM projects have different science goals, but will use identical telescopes. The first telescope, MeerLICHT, will be commissioned at Sutherland (South Africa) in the first quarter of 2017. It will co-point with MeerKAT to collect optical data commensurate with the radio observations. After careful analysis of MeerLICHT's performance, three telescopes of the same type will be commissioned in La Silla (Chile) in 2018 to form phase I of the BlackGEM array. BlackGEM aims at detecting and characterizing optical counterparts of gravitational wave events detected by Advanced LIGO and Virgo. In this contribution we present an overview of the science goals, the design and the status of the two projects.

This paper describes MRESim, a multi-robot exploration simulator which aims to provide a middle ground between the RoboCup Agent and Virtual Robot competitions. A detailed description of this new infrastructure is provided, followed by examples and case studies of successful research outcomes arising from the use of MRESim. Our work on MRESim won the 2014 Infrastructure competition of the RoboCup Rescue Simulation League.

Many robotics applications benefit from cooperative exploration by multiple robots. Often the environments that they operate in contain significant communication challenges due to their size or complexity. There has been much work in keeping teams of autonomously exploring robots connected to one another, but in certain environments, distant locations can only be reached if robots relay information via teammates or explore autonomously beyond team communication range.

Duurzaamheid wordt ook in de melkveehouderij steeds belangrijker. Duurzaamheid omvat veel verschillende aspecten die uiteindelijk bij elkaar komen en gewogen dienen te worden. Dit is zeker nog niet uitgekristalliseerd en diverse verkenningen zijn dan ook nodig. Daarnaast ligt er de vraag om duurzaamheid ook praktisch toepasbaar te maken als managementinstrument voor melkveehouders. Deze twee aspecten komen in dit rapport bij elkaar. Het doel van deze rapportage is dan ook inzicht te krijgen in de duurzaamheid van de veestapels van Koeien & Kansen-veehouders en de Duurzaamheidsmonitor van CRV toe te passen op een praktisch vraagstuk. In de Duurzaamheidsmonitor is een economisch kengetal opgenomen om een economische uitwerking van levensproductie, het Netto Dag Rendement (NDR), te laten zien.

Koeien & Kansen-veehouders doen hun best om goede milieuprestaties te leveren. Het projectdoel is dan ook om voor te lopen op de milieuwetgeving. Met bovengemiddelde milieuprestaties lijkt dit aardig te lukken. Maar hoe zit het met de veeprestaties? Krijgt dat dan minder aandacht? Is dat juist onder gemiddeld? Nou, niet dus. Gemiddeld hebben de veestapels van de Koeien & Kansen-bedrijven zelfs een hoger Netto Dag Rendement (NDR) dan het gemiddelde van de Nederlandse bedrijven. Dit is te zien in de figuur. Het gemiddelde NDR en het NDR van de 5% laagst scorende veestapels van Koeien & Kansen ligt beduidend hoger dan die van Nederland.

For many robotics applications (such as robotic search and rescue), information about the environment must be gathered by a team of robots and returned to a single, specific location. Coordination of robots and sharing of information is vital, and when environments have severe communication limitations, approaches must be robust to communication drop-out and failure. The difficulties are compounded in dynamic environments, where paths previously believed to be free can suddenly become blocked. In this paper, we introduce a novel way of calculating rendezvous points for robots to meet and share information. Using role-based exploration, some robots continuously explore the environment while others ferry information back and forth to a central command centre. Optimal rendezvous point selection leads to more efficient exploration, and allows robots to replan when one of them has unexpected obstacles in its path.

For many robotics applications (such as robotic search and rescue), information about the environment must be gathered by a team of robots and returned to a single, specific location. Coordination of robots and sharing of information is vital, and when environments have severe communication limitations, approaches must be robust to communication drop-out and failure. The difficulties are compounded in dynamic environments, where paths previously believed to be free can suddenly become blocked. In this paper, we introduce a novel way of calculating rendezvous points for robots to meet and share information. Using role-based exploration, some robots continuously explore the environment while others ferry information back and forth to a central command centre. Optimal rendezvous point selection leads to more efficient exploration, and allows robots to replan when one of them has unexpected obstacles in its path.

With the progress made in active exploration, the robots of the Joint Rescue Forces are capable of making deliberative decisions about the distribution of exploration locations over the team. Experiments have been done which include information exchange between team-members at rendez-vous points. Last year progress has been made with robots with advanced mobility, such as the Kenaf and the AirRobot. Currently our navigation algorithms are extended to be able to autonomously explore with the AirRobots. Robots equipped with both camera and laser-range scanners can learn a visual classifier of free space, which could be used by robots without laser-range scanners to navigate through the environment. Part of our algorithms have been validated on the Nomad Super Scout II robot available in our laboratory.

Teams of communicating robots are likely to be used for a wide range of applications in the near future, such as robotic search and rescue or robotic exploration of hostile and remote environments. In such scenarios, environments are likely to contain significant interference and multi-robot systems must be able to cope with loss of communication. We propose a novel multi-robot exploration approach, role-based exploration, in which members of the team explicitly plan to explore beyond communication range limits. Rendezvous points are calculated carefully to improve the exploration efficiency. A dynamic team hierarchy leads to additional gains. The result is a hybrid centralised/distributed behaviour that adjusts reactively to communication availability and environment size.

Thanks to advances in both computer science and engineering, the divide between robotics and multi-agent systems is shrinking. Robots are capable of performing an ever wider range of tasks, and there is an increasing need for solutions to high-level problems such as multi-agent coordination. In this paper we examine the problem of finding a robust exploration strategy for a team of mobile robots that takes into account communication limitations.We propose four performance metrics to evaluate and compare existing multi-robot exploration algorithms, and present a role-based approach in which robots either act as explorers or as relays. The result is a complete exploration of the environment in which information is efficiently returned to a central command centre, which is particularly applicable to the domain of rescue robotics.

With the progress made in active exploration, the robots of the Joint Rescue Forces are capable of making deliberative decisions about the distributing exploration locations over the team. To navigate autonomously towards those locations, the robots gradually aggregate their experience in a traversability map. This traversability map can be used as basis to calculate an optimal path towards a goal. Robots equipped with both camera and laser-range scanners can learn a visual classifier of free space, which could be used by robots without laser-range scanners to navigate through the environment. Part of our algorithms have been validated on the Nomad Super Scout II robot available in our laboratory.

With the progress made in active exploration, the robots of the Joint Rescue Forces are capable of making deliberative decisions about the distributing exploration locations over the team. To navigate autonomously towards those locations, the robots gradually aggregate their experience in a traversability map. This traversability map can be used as basis to calculate an optimal path towards a goal. Robots equipped with both camera and laser-range scanners can learn a visual classifier of free space, which could be used by robots without laser-range scanners to navigate through the environment. Part of our algorithms have been validated on the Nomad Super Scout II robot available in our laboratory.

Recent advances in robotics and computer science mean that it is now possible to use teams of robots for many real-world applications. One very important application is robotic search-and-rescue. Robots are highly suitable for search-and-rescue tasks since they may be deployed in dangerous and toxic environments without putting human responders at risk. Initial uses of rescue robots, such as during rescue efforts following the 2001 collapse of the World Trade Centre in New York, have highlighted the fact that many improvements are still required if robots are to provide extensive assistance in search-and-rescue scenarios. While much effort is going into development of more robust and mobile robot platforms, it is also necessary to develop advanced methods for multi-robot coordination and practical user interfaces for humans to control the robots. Here we describe an approach being developed jointly by Amsterdam’s Intelligent Systems Laboratory and the Oxford University Computing Laboratory that integrates advanced techniques from a variety of fields such as mapping, localization, exploration, communication, navigation and human-robot interface design. All research reported here is performed using the USARSim simulator.

With the progress made in active exploration, the robots of the Joint Rescue Forces are capable of making deliberative decisions about the frontiers to be explored. The robots select the frontiers having maximum information gain, taking into account potential communication limitations. The robots incorporate the positions of their team mates into their decisions, to optimize the gain for the team as a whole. Active exploration is based on a shared occupancy map, which is generated online. The images of the omnidirectional camera can be used to automatically detect victims and to add additional information to the map.

Recent rapid advances in technology mean that robots are being used for an ever widening range of tasks. While traditional robotics tasks have typically involved robots operating individually, there is now an increasing need for development of techniques that may be useful for cooperation between robots, in other words for multi-agent cooperation. This field requires robust and versatile solutions since robots must typically operate in noisy and uncertain environments. Robot football is an increasingly popular academic discipline worldwide. The challenges offered by robot football are numerous, and solutions to robot football problems often apply to a wider range of robotics applications. This makes robot football an ideal testbed for the study of multi-agent cooperation problems. In this thesis, two areas of multi-agent cooperation are approached within the framework of robot football: collision planning and path planning. Artificial neural networks are applied to specific problems in each of these areas, and in both cases lead to an increase in performance. In the case of path planning, a novel approach is proposed. All experiments are undertaken within the simulator developed for the FIRA robot football simulation league. The results of these experiments indicate that machine learning techniques are well suited to solving multi-agent cooperation problems. Certain machine learning techniques are particularly suitable for certain types of problems. Machine learning techniques outperform non-learning techniques in a number of cases, and there is extensive scope for machine learning techniques to be applied to a wider range of collision and path planning problems, and to multi-agent collaboration problems in general.

A recently developed electron probe X-ray microanalysis (EPMA), called low-Z EPMA, employing an ultrathin window energy-dispersive X-ray detector, was applied to characterize aerosol particles collected at two sampling sites, namely, Kosan and 1100 Hill of Cheju Island, Korea, on a summer day in 1999. Since low-Z EPMA can provide quantitative information on the chemical composition of aerosol particles, the collected aerosol particles were classified and analyzed based on their chemical species. Many different particle types were identified, such as marine-originated, carbonaceous, soil-derived, and anthropogenic particles. Marine-originated particles, such as NaNO3- and Na2SO4- containing particles, are very frequently encountered in the two samples. In this study, it was directly proven that the observed nitrate particles were from sea salts. In addition, two types of nitrate particles from sea salts were observed, with and without Mg. The sodium nitrate particles without Mg were believed to be collected as crystalline form, either with the sodium nitrate particles being fractionally recrystallized within evaporating seawater drops or with recrystallized sodium chloride particles having reacted with gaseous nitrogen species in the air to form the crystalline sodium nitrate particles. The other seemed to be collected as seawater drops, where the atmospheric reaction had occurred in the droplets, and thus sodium as well as magnesium nitrates were observed. Carbonaceous particles are the most abundant in the samples at both sites. From this study, it was found that about three-quarters of the carbonaceous particles in the samples were biogenic, which partially explains a previously reported observation of a large concentration of organic carbon particles as compared to elemental carbon. Various soil-derived particles were also observed. In addition to aluminosilicate- and iron oxide-containing particles, which are ubiquitous components in soil-derived particles, CaCO3-, Al2O3- and Cr-containing particles were also frequently encountered.