932 research outputs found

    Duplex stainless steels for thermal energy storage: characterization of oxide scales formed in carbonate salts at 500 °C

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    Next generation concentrated solar power (CSP) plants promise a higher operating temperature and better efficiency. However, new issues related to the corrosion against protection of the construction alloys need to be solved. In this work, two different duplex stainless steels grades, namely 2205 (DS2205) and 2507 (DS2507), were evaluated for their compatibility with the eutectic molten salt mixture of Li2CO3-K2CO3-Na2CO3 at 500 °C in air for thermal energy storage applications. Corrosion tests combined with complementary microscopy, microanalysis and mechanical techniques were employed to study the oxide scales formed on the surface of the duplex steels. The corrosion tests evidenced that the attack morphology in both duplex steels was a uniform oxidative process without localized corrosion. DS2507 presented a better corrosion resistance than DS2205, due to the formation of thinner, compact and continuous oxide layers with higher compositional content in Cr, Ni and Mo than DS2205. The oxide scales of DS2507 showed more remarkable mechanical integrity and adhesion to the metallic substrate.Postprint (published version

    La enfermedad inflamatoria intestinal y los riesgos de enfermedad cardiovascular

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    La enfermedad inflamatoria intestinal (EII), comprende tanto a la colitis ulcerosa como a la enfermedad de Crohn, entidades consideradas enfermedades inmunomediadas, sistémicas y de curso crónico que conllevan a menudo el desarrollo de manifestaciones extraintestinales. A pesar de que el estudio de las comorbilidades haya sido desarrollado tradicionalmente en contexto de otras enfermedades inflamatorias sistémicas, este concepto está emergiendo también en la EII. Multitud de patologías han sido vinculadas a la EII, entre las que destaca la enfermedad cardiovascular, la primera causa de muerte en los países desarrollados. Los pacientes con EII están expuestos a un mayor riesgo de entidades tales como arterosclerosis precoz e infarto de miocardio, o trombosis venosas y tromboembolismo pulmonar. El objetivo de esta revisión es hacer una aproximación a la fisiopatología de las diferentes manifestaciones de la enfermedad cardiovascular en los pacientes con EII y de cómo prevenirlas. Inflammatory bowel disease (IBD) includes both ulcerative colitis and Crohn's disease, which are well recognised as chronic systemic and immune-mediated conditions that frequently involve extraintestinal manifestations. Although comorbidities have long been the subject of research in other chronic inflammatory diseases, this concept is also emerging in IBD. Many pathologies have been linked to IBD, including cardiovascular disease, which is the main cause of death in developed countries. IBD patients are at increased risk of conditions such as early atherosclerosis and myocardial infarction or venous thrombosis and pulmonary thromboembolism. The aim of this review is to make an approximation of the physiopathology of the different manifestations of cardiovascular disease in patients with IBD and how to prevent them

    Sustainability indicator for the prevention of potential thermal interferences between groundwater heat pump systems in urban aquifers

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    The steady increase of geothermal systems using groundwater is compromising the renewability of the geothermal resources in shallow urban aquifers. To ensure sustainability, scientifically-based criteria are required to prevent potential thermal interferences between geothermal systems. In this work, a management indicator (balanced sustainability index, BSI) applicable to groundwater heat pump systems is defined to assign a quantitative value of sustainability to each system, based on their intrinsic potential to produce thermal interference. The BSI indicator relies on the net heat balance transferred to the terrain throughout the year and the maximum seasonal thermal load associated. To define this indicator, 75 heating-cooling scenarios based in 23 real systems were established to cover all possible different operational conditions. The scenarios were simulated in a standard numerical model, adopted as a reference framework, and thermal impacts were evaluated. Two polynomial regression models were used for the interpolation of thermal impacts, thus allowing the direct calculation of the sustainability indicator developed as a function of heating-cooling ratios and maximum seasonal thermal loads. The BSI indicator could provide authorities and technicians with scientifically-based criteria to establish geothermal monitoring programs, which are critical to maintain the implementation rates and renewability of these systems in the cities

    Evaluation of dimensionality reduction methods applied to numerical weather models for solar radiation forecasting

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    The interest in solar radiation prediction has increased greatly in recent times among the scientific community. In this context, Machine Learning techniques have shown their ability to learn accurate prediction models. The aim of this paper is to go one step further and automatically achieve interpretability during the learning process by performing dimensionality reduction on the input variables. To this end, three non standard multivariate feature selection approaches are applied, based on the adaptation of strong learning algorithms to the feature selection task, as well as a battery of classic dimensionality reduction models. The goal is to obtain robust sets of features that not only improve prediction accuracy but also provide more interpretable and consistent results. Real data from the Weather Research and Forecasting model, which produces a very large number of variables, is used as the input. As is to be expected, the results prove that dimensionality reduction in general is a useful tool for improving performance, as well as easing the interpretability of the results. In fact, the proposed non standard methods offer important accuracy improvements and one of them provides with an intuitive and reduced selection of features and mesoscale nodes (around 10% of the initial variables centered on three specific nodes).This work has been partially supported by the projects TIN2014-54583-C2-2-R, TEC2014-52289-R and TEC2016-81900-REDT of the Spanish Interministerial Commission of Science and Technology (MICYT), and by Comunidad Autónoma de Madrid, under project PRICAM P2013ICE-2933

    Elucidation of the ebola virus VP24 cellular interactome and disruption of virus biology through targeted inhibition of host-cell protein function

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    Viral pathogenesis in the infected cell is a balance between antiviral responses and subversion of host-cell processes. Many viral proteins specifically interact with host-cell proteins to promote virus biology. Understanding these interactions can lead to knowledge gains about infection and provide potential targets for antiviral therapy. One such virus is Ebola, which has profound consequences for human health and causes viral hemorrhagic fever where case fatality rates can approach 90%. The Ebola virus VP24 protein plays a critical role in the evasion of the host immune response and is likely to interact with multiple cellular proteins. To map these interactions and better understand the potential functions of VP24, label-free quantitative proteomics was used to identify cellular proteins that had a high probability of forming the VP24 cellular interactome. Several known interactions were confirmed, thus placing confidence in the technique, but new interactions were also discovered including one with ATP1A1, which is involved in osmoregulation and cell signaling. Disrupting the activity of ATP1A1 in Ebola-virus-infected cells with a small molecule inhibitor resulted in a decrease in progeny virus, thus illustrating how quantitative proteomics can be used to identify potential therapeutic targets

    On-the-Fly Adaptive Routing for dragonfly interconnection networks

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    Adaptive deadlock-free routing mechanisms are required to handle variable traffic patterns in dragonfly networks. However, distance-based deadlock avoidance mechanisms typically employed in Dragonflies increase the router cost and complexity as a function of the maximum allowed path length. This paper presents on-the-fly adaptive routing (OFAR), a routing/flow-control scheme that decouples the routing and the deadlock avoidance mechanisms. OFAR allows for in-transit adaptive routing with local and global misrouting, without imposing dependencies between virtual channels, and relying on a deadlock-free escape subnetwork to avoid deadlock. This model lowers latency, increases throughput, and adapts faster to transient traffic than previously proposed mechanisms. The low capacity of the escape subnetwork makes it prone to congestion. A simple congestion management mechanism based on injection restriction is considered to avoid such issues. Finally, reliability is considered by introducing mechanisms to find multiple edge-disjoint Hamiltonian rings embedded on the dragonfly, allowing to use multiple escape subnetworks

    Clinical factors associated with discontinuation of ts/bDMARDs in rheumatic patients from the BIOBADASER III registry

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    Altres ajuts: Spanish Agency of Medicines and Medical Devices (AEMPS); Biogen; Bristol Myers-Squibb (BMS); Celltrion Healthcare; Lilly; Merck; Novartis; Pfizer; Regeneron Pharmaceuticals; Samsung Bioepis.Biologic and targeted synthetic disease-modifying antirheumatic drugs (ts/bDMARDs) play a pivotal role in the treatment of rheumatoid arthritis (RA), psoriatic arthritis (PsA), and ankylosing spondylitis (AS). Persistence of therapy provides an index of a drug's overall effectiveness. The objective of the study was to identify factors associated with discontinuation of ts/bDMARDs in a real-world dataset. The study population comprised patients diagnosed with RA, PsA, and AS included in the BIOBADASER registry for whom follow-up data were available until November 2019. Patient features and treatment data were included in the analysis. The Kaplan-Meier method was used to study survival of the different drugs according to the reason for discontinuation. Factors associated with discontinuation were studied using Cox regression models and bivariate and multivariate analyses. P values of less than 0.05 were regarded as statistically significant. The study population comprised 4,752 patients who received a total of 8,377 drugs, of which 4,411 (52.65%) were discontinued. The Kaplan-Meier curves showed that survival for first-line treatment was greater in all 3 groups (p < 0.001). Patients with RA had a greater risk of discontinuation if they were younger (HR, 0.99; 95% CI 0.99-1.00), if they were receiving anti-TNFα agents (HR, 0.61; 95% CI 0.54-0.70), and if they had more comorbid conditions (HR, 1.09; 95% CI 1.00-1.17). Patients with PsA had a higher risk if they were women (HR, 1.36; 95% CI 1.15-1.62) and if they were receiving other ts/bDMARDs (HR, 1.29; 95% CI 1.05-1.59). In patients with AS, risk increased with age (HR, 1.01; 95% CI 1.00-1.02), as did the number of comorbid conditions (HR, 1.27; 95% CI 1.12-1.45). The factors that most affected discontinuation of ts/bDMARDs were line of treatment, age, type of drug, sex, comorbidity and the year of initiation of treatment. The association with these factors differed with each disease, except for first-line treatment, which was associated with a lower risk of discontinuation in all 3 diseases

    ACS imaging of star clusters in M51. I. Identification and radius distribution

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    We use HST/ACS observations of the spiral galaxy M51 in F435W, F555W and F814W to select a large sample of star clusters with accurate effective radius measurements in an area covering the complete disc of M51. We present the dataset and study the radius distribution and relations between radius, colour, arm/interarm region, galactocentric distance, mass and age. We select a sample of 7698 (F435W), 6846 (F555W) and 5024 (F814W) slightly resolved clusters and derive their effective radii by fitting the spatial profiles with analytical models convolved with the point spread function. The radii of 1284 clusters are studied in detail. We find cluster radii between 0.5 and ~10 pc, and one exceptionally large cluster candidate with a radius of 21.6 pc. The median radius is 2.1 pc. We find 70 clusters in our sample which have colours consistent with being old GC candidates and we find 6 new "faint fuzzy" clusters in, or projected onto, the disc of M51. The radius distribution can not be fitted with a power law, but a log-normal distribution provides a reasonable fit to the data. This indicates that shortly after the formation of the clusters from a fractal gas, their radii have changed in a non-uniform way. We find an increase in radius with colour as well as a higher fraction of redder clusters in the interarm regions, suggesting that clusters in spiral arms are more compact. We find a correlation between radius and galactocentric distance which is considerably weaker than the observed correlation for old Milky Way GCs. We find weak relations between cluster luminosity and radius, but we do not observe a correlation between cluster mass and radius.Comment: 17 pages, 23 figures. Accepted for publication in A&

    Contrasting molluscan fauna collected with beam trawl and otter trawl in circalittoral and bathyal soft bottoms of the northern Alboran Sea

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    The Alboran Sea display complex oceanographic, geological, ecological and biological processes, promoting a high biodiversity and complexity (Robles, 2010). On the other hand, molluscs constitute one of the most diverse and best represented invertebrate groups in this area, representing an important component of soft bottom communities, as well as the second group in abundance and biomass in demersal fisheries, with species of ecological and commercial importance worldwide (Gofas et all., 2011). The study of the molluscan assemblages is important where trawling fishing fleets operate, in order to improve fisheries assessment and move forward to an ecosystem based approach, which takes into account other components of the fishery than the target species such as non-target and protected species and habitats (Pikitch et al., 2004). Information collected on fisheries assemblages may introduce a bias depending on the fraction of the assemblage (e.g. demersal, epifaunal, infaunal) at which the sampling method is targeted, particularly in a group such as molluscs with a high variability in life strategies. The aims of this study are 1) to increase the scarce knowledge on the composition and structure of molluscan assemblages of circalittoral and bathyal soft bottoms of the Alboran Sea; and 2) to compare the information obtained on these assemblages by using two different types of sampling gears, the beam trawl and the otter trawl. During the MEDITS trawl surveys (springs 2014 and 2015) a beam trawl (BT) (horizontal opening 1.3 x vertical opening 1.2 m, mesh size 10 mm) and an otter trawl (OT)(GOC 73) (2.5 x 21.5 m , mesh size 20 mm) were used in 35 sampling stations at depths from 40 to 800 m in the Alboran Sea. Catches were sorted to species and their individuals counted and weighed. The molluscan assemblages and species were characterized according to their dominance (%Da) and frequency of occurrence (%F). Multivariate analyses using the Bray-Curtis index were performed with presence/absence species data and quantitative data obtained with each method were standardized to a similar sampling area. ANOSIM was used for testing the differences between groups of samples according to different factors (depth and sampling type) and SIMPER for the contribution of the different species to these factors using PRIMER v6. The characterization of the different types of sampling and assemblages was done with the species richness and statistical differences tested with Kruskal-Wallis using SPSS software. A total of 170 spp. have been collected, with 69 species collected in OT samples, mostly cephalopods (26 spp., 37.68%), followed by gastropods (25 spp., 36.23%) and bivalves (18 species, 26.10% total species of OT), being the latter the most abundant group. The top-dominant species were the bivalve Neopycnodonte cochlear and the cephalopod Alloteuthis media, whereas the most frequent ones were the cephalopods Octopus vulgaris, Todarodes sagittatus and Illex coindetii (Fig. 1 ). In beam trawl samples, 135 spp. of 6 classes were found, being gastropods the most diverse and abundant one (69 spp., 51.11% total species of BT), followed by bivalves (49 spp., 36.3%) and cephalopods (15 spp., 11.11%). The top-dominant species were the gastropods Turritella communis and Nassarius ovoideus and the bivalves Nucula sulcata and Abra longicallus, and the most frequent ones included Nucula sulcata, Nassarius ovoideus and the gastropod Euspira fusca (Figure 1). Contrasting both methods, only 20% (34 spp.) of the species were exclusively collected in OT samples (e.g. Alloteuthis spp., I. coindetii, Loligo spp., T. sagittatus) and 57% (97 spp.) in BT samples (e.g. N. ovoideus, Timoclea ovata, N. sulcata, Clelandella miliaris). Only 23% of the species (39 spp.) were collected with both methods (e.g. Venus nux, Turritella communis, N. cochlear). Figure 1. Some common and dominant mollusc of beam trawl (A-C, E-G) and otter trawl samples (D, H-J) collected in circalittoral and bathyal soft bottoms of the northern Alboran Sea. A) Turritella communis; B) Abra longicallus; C) Nassarius ovoideus; D) Illex coindeitii; E) Clelandella miliaris; F) Timoclea ovata; G) Nucula sulcata; H) Venus nux; I) Octopus vulgaris; J) Neopycnodonte cochlear. Multivariate analyses clearly separated two groups of samples, each one collected with a different sampling method, and in each grouping it revealed three main mollusks assemblages in relation to depth: I) Continental shelf (CS) (40-200 m), II) Upper slope (UCS) (201-400 m), and III) and Middle slope (MCS) (400-1800 m) (Fig. 2). Figure 2. MDS applied to presence-absence data of molluscs assemblages obtained from beam trawl and otter trawl samples collected in the northern Alboran Sea. BT: Beam trawl; OT: Otter trawl ; CS: Continental Shelf; UCS: Upper Continental Slope; MCS: Middle Continental Slope. The continental shelf assemblage in BT samples were characterized by T. ovata, N. cochlear, N. ovoideus and T. communis, whereas O. vulgaris, Eledone moschata and I. coindetii characterized the OT samples. For the upper and middle slope assemblages, E. fusca and A. longicallus characterized the BT samples, whereas T. sagittatus and Bathypolypus sponsalis characterized the OT samples. Mean values of species richness were significantly higher when using the BT. This study showed that OT nor BT samples can provide complete information on the whole molluscan assemblage, giving each sampling method complimentary information. The demersal and epi-benthic fractions of the community were better sampled using the otter trawl and the beam trawl, respectively. The estimates of infauna were higher using the beam trawl, but this information should be contrasted with data obtained from dredges in order to assess whether the beam trawl yield acceptable estimates of the abundance of these molluscs
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