An evolutionary approach to the delimitation of labour market areas: an empirical application for Chile

An evolutionary approach to the delimitation of labour market areas: an empirical application for Chile. Spatial Economic Analysis. Labour market areas (LMAs) are argued to represent a more appropriate policy framework than administrative units for the analysis of spatial labour market activity. This article develops LMAs for Chile by applying an evolutionary computation approach. This innovative approach defines LMAs through an optimization process by maximization of internal cohesion, subject to restrictions of minimum levels of self-containment and population. To evaluate the appropriateness of the LMAs, comparative analyses are performed between alternative delimitations based on different parameter configurations of the proposed method versus administrative boundaries and the most widely used method for official LMA delimitation, the travel-to-work areas method

Cold Isostatic Pressing to Improve the Mechanical Performance of Additively Manufactured Metallic Components.

Additive manufacturing is becoming a technique with great prospects for the production of components with new designs or shapes that are difficult to obtain by conventional manufacturing methods. One of the most promising techniques for printing metallic components is binder jetting, due to its time efficiency and its ability to generate complex parts. In this process, a liquid binding agent is selectively deposited to adhere the powder particles of the printing material. Once the metallic piece is generated, it undergoes a subsequent process of curing and sintering to increase its density (hot isostatic pressing). In this work, we propose subjecting the manufactured component to an additional post-processing treatment involving the application of a high hydrostatic pressure (5000 bar) at room temperature. This post-processing technique, so-called cold isostatic pressing (CIP), is shown to increase the yield load and the maximum carrying capacity of an additively manufactured AISI 316L stainless steel. The mechanical properties, with and without CIP processing, are estimated by means of the small punch test, a suitable experimental technique to assess the mechanical response of small samples. In addition, we investigate the porosity and microstructure of the material according to the orientations of layer deposition during the manufacturing process. Our observations reveal a homogeneous distribution independent of these orientations, evidencing thus an isotropic behaviour of the material

Influence of charging conditions on simulated temperature-programmed desorption for hydrogen in metals

Failures attributed to hydrogen embrittlement are a major concern for metals so a better understanding of damage micro-mechanisms and hydrogen diffusion within the metal is needed. Local concentrations depend on transport phenomena including trapping effects, which are usually characterised by a temperature-programmed desorption method often referred to as Thermal Desorption Analysis (TDA). When the hydrogen is released from the specimen during the programmed heating, some desorption peaks are observed that are commonly related to detrapping energies by means of an analytical procedure. The limitations of this approach are revisited here and gaseous hydrogen charging at high temperatures is simulated. This popular procedure enables attaining high concentrations due to the higher solubility of hydrogen at high temperatures. However, the segregation behaviour of hydrogen into traps depends on charging time and temperature. This process and the subsequent cooling alter hydrogen distribution are numerically modelled; it is found that TDA spectra are strongly affected by the charging temperature and the charging time, both for weak and strong traps. However, the influence of ageing time at room temperature after cooling and before desorption is only appreciable for weak traps

A Simulation Workflow for Membrane Computing: From MeCoSim to PMCGPU Through P-Lingua

P system simulators are of high importance in Membrane Computing, since they provide tools to assist on model validation and verification. Keeping a balance between generality and flexibility, on the one side, and efficiency, on the other hand, is always challenging, but it is worth the effort. Besides, in order to prove the feasibility of P system models as practical tools for solving problems and aid in decision making, it is essential to provide functional mechanisms to have all the elements required at disposal of the potential users smoothly integrated in a robust workflow. The aim of this paper is to describe the main components and connections within the approach followed in this pipeline.Ministerio de Industria, Economía y Competitividad TIN2017-89842-

Late Burdigalian (Miocene) age for pectinids (Mollusca-Bivalvia) from the Pirabas Formation (northern Brazil) derived from Sr-isotope (87 Sr/86 Sr) data

The faunas of the highly fossiliferous Pirabas Formation belong to the southern part of the biogeographical unit known as "Neogene Tropical America". This unit developed prior to the closure of the Central American Seaway by the Isthmus of Panama. Until now, the age of the Pirabas Formation was inferred only from biostratigraphy. The Sr-isotope (87 Sr/86 Sr) values of pectinid shells from the Pirabas Formation show that most parts of this unit were deposited during the Late Burdigalian (about 16-17 Ma). This result does not contradict biostratigraphic data and it constrains the age of the Pirabas Formation more tightly than do previous estimates of age, it for future, more precise biogeographical comparisons

Gaussian-process-based demand forecasting for predictive control of drinking water networks

Trabajo presentado a la 9th International Conference on Critical Information Infrastructures Security, celebrada en Limassol (Chipre) del 13 al 15 de octubre de 2014.This paper focuses on short-term water demand forecasting for predictive control of DrinkingWater Networks (DWN) by using Gaussian Process (GP). For the predictive control strategy, system state prediction in a nite horizon are generated by a DWN model and demands are regarded as system disturbances. The goal is to provide a demand estimation within a given condence interval. For the sake of obtaining a desired forecasting performance, the forecasting process is carried out in two parts: the expected part is forecasted by Double-Seasonal Holt-Winters (DSHW) method and the stochastic part is forecasted by GP method. The mean value of water demand is rstly estimated by DSHW while GP provides estimations within a condence interval. GP is applied with random inputs to propagate uncertainty at each step. Results of the application of the proposed approach to a real case study based on the Barcelona DWN have shown that the general goal has been successfully reached.This work is partially supported by the research projects SHERECS DPI-2011-26243 and ECOCIS DPI-2013-48243-C2-1-R, both of the Spanish Ministry of Education, by EFFINET grant FP7-ICT-2012-318556 of the European Commission and by AGAUR Doctorat Industrial 2013-DI-041. Ye Wang also thanks China Scholarship Council for providing postgraduate scholarship.Peer Reviewe

Pre-notched dog bone small punch specimens for the estimation of fracture properties

In recent years, the pre-notched or pre-cracked small punch test (P-SPT) has been successfully used to estimate the fracture properties of metallic materials for cases in which there is not sufficient material to identify these properties from standard tests, such as CT or SENB specimens. The P-SPT basically consists of deforming a pre-notched miniature specimen, whose edges are firmly gripped by a die, using a high strength punch. The novelty of this paper lies in the estimation of fracture properties using dog-bone-shaped specimens with different confinement levels. With these specimens, three confinement variations have been studied. The results obtained enable the establishment of a variation of fracture properties depending on the level of confinement of each miniature specimen and selection of the most appropriate confinement for this goal

Long-term ecological changes in Mediterranean mountain lakes linked to recent climate change and Saharan dust deposition revealed by diatom analyses

Anthropogenic climate change and the recent increase of Saharan dust deposition has had substantial effects on Mediterranean alpine regions. We examined changes in diatom assemblage composition over the past ~180 years from high-resolution, dated sediment cores retrieved from six remote lakes in the Sierra Nevada Mountains of Southern Spain. In all lakes, changes in diatom composition began over a century ago, but were more pronounced after ~1970 CE, concurrent with trends in rising regional air temperature, declining precipitation, and increased Saharan dust deposition. Temperature was identified as the main predictor of diatom assemblage changes, whereas both Saharan dust deposition drivers, the Sahel precipitation index and the winter North Atlantic Oscillation, were secondary explanatory variables. Diatom compositional shifts are indicative of lake alkalinization (linked to heightened evapoconcentration and an increase in calcium-rich Saharan dust input) and reduced lake water turbulence (linked to lower water levels and reduced inflows to the lakes). Moreover, decreases in epiphytic diatom species were indicative of increasing aridity and the drying of catchment meadows. Our results support the conclusions of previous chlorophyll-a and cladoceran-based paleolimnological analyses of these same dated sedimentary records which show a regional-scale response to climate change and Saharan dust deposition in Sierra Nevada lakes and their catchments during the 20th century. However, diatom assemblages seem to respond to different atmospheric and climate-related effects than cladoceran assemblages and chlorophyll-a concentrations. The recent impact of climate change and atmospheric Saharan deposition on lake biota assemblages and water chemistry, as well as catchment water availability, will have important implications for the valuable ecosystem services that the Sierra Nevada provides

An overview of the lower cretaceous dinosaur tracksites from the mirambel formation in the iberian range (ne spain)

Up to now, the ichnological vertebrate record from the Barremian Mirambel Formation (NE Spain) has remained completely unknown despite the fact that osteological findings have been reported in recent years. Here we provide an overview of 11 new dinosaur tracksites found during a fieldwork campaign in the year 2011. The majority of these tracksites (seven) preserve small- to medium-sized tridactyl tracks here assigned to indeterminate theropods. Only one footprint presents enough characters to classify it as Megalosauripus isp. Ornithopod tracks identified as Caririchnium isp. and Iguanodontipodidae indet. and sauropod tracks are recorded at two tracksites. The footprints are preserved in a variety of paleoenvironmental conditions and thus display different kinds of preservation (true tracks, shallow undertracks, natural casts and undertrack casts). The ichnological record from the Mirambel Formation seems to be theropod dominated. This is a clear discrepancy with the osteological record identified in this formation, which shows a predominance of ornithopod dinosaurs