High-temperature tribological performance of functionally graded Stellite 6/WC metal matrix composite coatings manufactured by laser-directed energy deposition

Wear-driven tool failure is one of the main hurdles in the industry.This issue can be addressed through surface coating with ceramic-reinforced metal matrix composites.However,the maximum ceramic content is limited by cracking.In this work,the tribological behaviour of the functionally graded WC-ceramic-particlereinforced Stellite 6 coatings is studied.To that end,the wear resistance at room temperature and 400°C is investigated.Moreover,the tribological analysis is supported by crack sensitivity and hardness evaluation,which is of utmost importance in the processing of composite materials with ceramic-particle-reinforcement.Results indicate that functionally graded materials can be employed to increase the maximum admissible WC content,hence improving the tribological behaviour,most notably at high temperatures.Additionally,a shift from abrasive to oxidative wear is observed in high-temperature wear testing.

Impact of surface roughness on the coefficient of friction of polymer-on-polymer contacts for deflection pulley-rope systems in the lift industry

The coefficient of friction(CoF)between the deflection pulley and rope in a lift strongly affects the life span of the rope.Although surface roughness is a key factor affecting the metallic pulley–rope CoF,its effect on polymeric pulleys is unknown.The present study analyses the effect of roughness and working conditions on cast polyamide 6(PA6G)deflection pulley–thermoplastic polyurethane(TPU)-coated rope contacts.The statistical analysis revealed that the effect of surface roughness on the CoF for low-load tests was significant.The present study contributes significantly to parameter selection in deflection pulley machining to minimise friction between the pulley and rope.

Earth observations for sustainable development goals monitoring based on essential variables and driver-pressure-state-impactresponse indicators

In recent years,researchers of different communities have increased their efforts in formalizing a set of measurements regularly collected for analysing changes in Drivers,States,Impacts and Responses of a given discipline.In some cases,different actors have converged in a minimum set of Essential Variables(EVs),such as for Climate,Biodiversity or Oceans.The definition of such EVs is an ongoing evolution and in extension(e.g.EVs for water)although some communities have not even started(e.g.agriculture and energy).This paper characterizes the Earth Observation(EO)networks and creates a graph representation of their relations.Secondly,this graph is enriched with the EVs produced by each network creating a knowledge base.Finally,an effort has been done to identify links between EVs and Sustainable Development Goals(SDG)indicators in a way that they indirectly connect the EO.An analysis to detect gaps in EO variables due to a lack of observational networks is performed.Several suggestions for improving SDG indicators framework by considering EVs are exposed,as well as proposing new necessary EVs and suggesting new EO based indicators.The complete graph is available in the ENEON website(http://www.eneon.net/graphev-sdg/).

Developing spatially and thematically detailed backdated maps for land cover studies

Global or regional land cover change on a decadal time scale can be studied at a high level of detail using the availability of remote sensing data such as that provided by Landsat.However,there are three main technical challenges in this goal.First,the generation of land cover maps without reference data is problematic(backdating).Second,it is important to maintain high accuracies in land cover change map products,requiring a reasonably rich legend within each map.Third,a high level of automation is necessary to aid the management of large volumes of data.This paper describes a robust methodology for processing time series of satellite data over large spatial areas.The methodology includes a retrospective analysis used for the generation of training and test data for historical periods lacking reference information.This methodology was developed in the context of research on global change in the Iberian Peninsula.In this study we selected two scenes covering geographic regions that are representative of the Iberian Peninsula.For each scene,we present the results of two classifications(1985-1989 and 2000-2004 quinquennia),each with a legend of 13 categories.An overall accuracy of over 92%was obtained for all 4 maps.

Building the World Wide Hypermap(WWH)with a RESTful architecture

The hypermap concept was introduced in 1992 as a way to hyperlink geospatial features to text,multimedia or other geospatial features.Since then,the concept has been used in several applications,although it has been found to have some limitations.On the other hand,Spatial Data Infrastructures(SDIs)adopt diverse and heterogeneous service oriented architectures(SOAs).They are developed by different standard bodies and are generally disconnected from mass market web solutions.This work expands the hypermap concept to overcome its limitations and harmonise it with geospatial resource oriented architecture(ROA),connecting it to the semantic web and generalising it to the World Wide Hypermap(WWH)as a tool for building a single‘Digital Earth’.Global identifiers,dynamic links,link purposes and resource management capabilities are introduced as a solution that orchestrates data,metadata and data access services in a homogeneous way.This is achieved by providing a set of rules using the current Internet paradigm formalised in the REpresentational State Transfer(REST)architecture and combining it with existing Open Geospatial Consortium(OGC)and International Organization for Standardization(ISO)standards.A reference implementation is also presented and the strategies needed to implement the WWH,which mainly consist in a set of additions to current Geographic Information System(GIS)products and a RESTful server that mediates between the Internet and the local GIS applications.