Modeling the hot flow behavior of a Fe-22Mn-0.41C-1.6Al-1.4Si TWIP steel microalloyed with Ti, V and Nb

The present research work analyses the influence of Ti, V and Nb microalloying elements on the hot flow behavior of a high-Mn Twinning Induced Plasticity (TWIP) steel. For this purpose, flow curves were obtained by uniaxial hot compression tests performed at four strain rates (10(-1), 10(-2), 10(-3) and 10(-4) s(-1)) and three temperatures (900, 1000 and 1100 degrees C). The models of Estrin, Mecking and Berg-strom; Avrami and Tegart, and Sellars were applied to determine the hot working constants used to derive the constitutive equations describing the flow curves. The analysis of modeling parameters of the hot flow curves shows that Ti, V and Nb additions to TWIP steel generated slight increase in the peak stress (sigma(p)), retardation of the dynamic recrystallization (DRX) onset, particularly at low temperature, and decrease in the activation energy required to recrystallization (Q(t)). Likewise, the softening effect promoted by DRV and DRX was more evident at high temperatures and low strain rates. On the other hand, the resulting deformed microstructures, analyzed by the SEM-EBSD technique, showed that the most important refining effect on recrystallized austenitic grain was in the presence of V and Ti. The good agreement between the experimental and predicted hot flow curves demonstrated that the developed constitutive equations predict with reasonable accuracy the hot flow behavior of the studied TWIP steels. (C) 2015 Elsevier B.V. All rights reserved.Peer ReviewedPostprint (author's final draft

Real-Time Prediction of Gamers Behavior Using Variable Order Markov and Big Data Technology: A Case of Study

This paper presents the results and conclusions found when predicting the behavior of gamers in commercial videogames datasets. In particular, it uses Variable-Order Markov (VOM) to build a probabilistic model that is able to use the historic behavior of gamers and to infer what will be their next actions. Being able to predict with accuracy the next user’s actions can be of special interest to learn from the behavior of gamers, to make them more engaged and to reduce churn rate. In order to support a big volume and velocity of data, the system is built on top of the Hadoop ecosystem, using HBase for real-time processing; and the prediction tool is provided as a service (SaaS) and accessible through a RESTful API. The prediction system is evaluated using a case of study with two commercial videogames, attaining promising results with high prediction accuracies

Circumnuclear structure and kinematics in the active galaxy NGC 6951

A study is presented of the central structure and kinematics of the galaxy NGC 6951, by means of broad band B'IJK images and high resolution high dispersion longslit spectroscopy, together with archival HST WFPC2 V and NICMOS2 J and H images. We find that there is evidence of two modes of star formation, in bursts and continuously. The equivalent width of the CaII triplet absorption lines show that, in the metal rich central region, the continuum is dominated by a population of red supergiants. The gaseous and stellar kinematics along three slit position angles, suggest the existence of a hierarchy of disks within disks, whose dynamics are decoupled at the two ILRs, that we find at 180 pc and at 1100 pc. This is supported by the structure seen in the high resolution HST images. The nucleus is spatially resolved within a radius of 1.5 arcsec, just inside the innermost ILR. Outside the iILR, the stellar CaT velocity profile is resolved into two components, associated with the bar and the disk. Several results indicate that this is a dynamically old system. It is thus possible that a nuclear bar has existed in NGC 6951 that drove the gas towards the nucleus, as in the bars within bars scenario, but that this bar has already dissolved by the gas accumulated within the circumnuclear region. We discuss the possibility that the kinematical component inside the iILR could be due to a nuclear outflow produced by the combined effects of SN and SN remnants, or to a nuclear disk, as in the disk within disk scenario that we propose for the fueling of the AGN in NGC 6951.Comment: 14 pages, 16 figures. Accepted for publication in Astronomy and Astrophysics. High resolution images in http://www.iaa.es/~eperez/research/degas.htm

Influence of Nb microaddition on microstructure and texture evolution in a Fe-21Mn-1.3Al-1.5Si-0.5C TWIP steel under uniaxial hot-tensile conditions

Advanced high-strength steels as Twinning Induced Plasticity (TWIP) steels have been developed using microalloying elements and subsequent thermo-mechanical processing techniques. Moreover, under hot-working conditions, these steels undergo significant microstructural changes as a result of preferred crystallographic orientation (texture) of grains. In order to evaluate this behavior, one non-microalloyed and other single Nb-microalloyed TWIP steels were melted in an induction furnace and cast into metal and sand molds. Samples with austenitic grain sizes between 400 and 2000 µm were deformed at 800 °C and strained at a constant strain rate of 10-3 s-1, and deformation state was examined by means of electron backscatter diffraction (EBSD) technique near to the fracture tip. It was found that non-microalloyed TWIP steel solidified in both metal and sand mold exhibits dynamically recrystallized grains. On the other hand, Nb microaddition has a strong influence in TWIP steel retarding the onset of recrystallization kinetics, showing low angle sub-structured grains. Furthermore, it was possible identifying the crystallographic orientation of grains using the inverse pole figures (IPF) and the orientation distribution function (ODF). Weak cube {001} recrystallization and E{111} ¿-fiber deformation textures components were detected.Peer ReviewedPostprint (author's final draft

An Efficient and Scalable Recommender System for the Smart Web

This proceeding at: 11th International Conference on Innovations in Information Technology (IIT) Innovations 2015. Special Theme: Smart Cities, Big Data, Sustainable Development. Took place at 2015, November, 01 - 03, in Dubai, United Arab Emirates (IEEE IIT 2015).This work describes the development of a web recommender system implementing both collaborative filtering and content-based filtering. Moreover, it supports two different working modes, either sponsored or related, depending on whether websites are to be recommended based on a list of ongoing ad campaigns or in the user preferences. Novel recommendation algorithms are proposed and implemented, which fully rely on set operations such as union and intersection in order to compute the set of recommendations to be provided to end users. The recommender system is deployed over a real-time big data architecture designed to work with Apache Hadoop ecosystem, thus supporting horizontal scalability, and is able to provide recommendations as a service by means of a RESTful API. The performance of the recommender is measured, resulting in the system being able to provide dozens of recommendations in few milliseconds in a single-node cluster setup.This research work is part of Memento Data Analysis project, co-funded by the Spanish Ministry of Industry, Energy and Tourism with no. TSI-020601-2012-99 and TSI-020110-2009-137.Publicad

PRESENTACIÓN

In this article we will study the expansion of the olive grove in andalusia throughout the modern period, putting it in relation to political, social and economic circumstances. olive oil was a product dedicated to trade, mainly in the outside and linked to the wool market, and therefore its demand depended on the development of national and foreign draperies, and the circumstances of foreign policy. The sectors involved in the trade will be responsible for financing most of this expansion, the formation of larger units of exploitation, and the building of mills and constructions which often become interesting buildings.Es obligado comenzar esta introducción al monográfico de este número de la revista Cuadernos de Prehistoria y Arqueología de la Universidad de Granada dedicado al expolio arqueológico con una referencia a la actualidad inmediata, aun a riesgo de trastocar una ordenación más lógica de esta exposición. En Siria, la guerra civil que asola el país desde 2011, y que está afectando al patrimonio cultural desde las primeras cruentas represiones del gobierno de Bachar el Asad (http://apsa2011.com), nos ha entregado las dolorosas imágenes del asesinato de Jaled Assad, quien fuese jefe de las Antigüedades de Palmira, y más tarde la voladura del templo de Baal y de un arco del triunfo en esa misma ciudad. Acciones perpetradas por el grupo insurgente denominado Estado Islámico, cuyo control sobre ese enclave declarado en 1980 como patrimonio de la humanidad hace presagiar que estas no sean las únicas nuevas a lamentar cuando este volumen vea la luz

The necessary change of model in the spanish professional archaeology

Los arqueólogos profesionales son aquellas personas que viven del ejercicio liberal de la Arqueología. Resulta preocupante que se haya convertido en un tópico señalar que la Arqueología profesional está en crisis. Las causas podrían resumirse en tres. En primer lugar, sus practicantes desempeñan un difícil papel intermedio entre las administraciones culturales, por un lado, y los promotores, por otro. De la primera dependen para desarrollar las actividades que son encargadas por los segundos, quienes lo hacen no por convicción sino para satisfacer las obligaciones impuestas normativamente. Una segunda causa de insatisfacción procede de la dejación, por parte de las administraciones culturales, de algunas de las responsabilidades sobre la Arqueología preventiva en manos de los promotores y propietarios de suelo, como aplicación del neoliberalismo más descarnado. Por último, la relación con la administración cultural normalmente resulta fluida, pero ello no evita los tiempos, en muchas ocasiones inexplicables, que la burocratización ha impuesto para culminar trámites, como el de las autorizaciones de actividades arqueológicas. En este trabajo identificamos estas tres circunstancias como el problema de la Arqueología profesional y la causa del malestar de quienes la practican, pero también proponemos una solución para resolver esos desajustes que, lejos de ser coyunturales, se han vuelto sistémicos en la gestión de la Arqueología preventiva y, por tanto, imposibles de atajar si no se cambia de modelo.Professional archaeologists to be people who make their living through the practice of archaeology. In this regard, it has become disturbingly commonplace to note that professional archaeology is in crisis. The reasons are threefold. First, its practitioners play a difficult intermediate role between cultural authorities, on the one hand, and developers, on the other. They depend on the former to carry out the activities commissioned from them by the latter, who, in turn, commission those activities not out of conviction, but to meet their legal obligations. The second cause of dissatisfaction stems from the fact that cultural authorities have handed over some of their responsibilities for preventive archaeology to developers and landowners, in an example of stark neoliberalism. Finally, although the relationship with cultural authorities is usually fluid, that does not prevent bureaucratization from imposing often inexplicable deadlines for processing formalities such as permits for archaeological activities. In this paper, we identify these three circumstances as the problem facing professional archaeology and the cause of the malaise affecting its practitioners. However, we also propose a solution to address these challenges, which, far from temporary, have become systematic in the management of preventive archaeology and, therefore, impossible to check without a change of model

Secondary metabolites from two species of Tolpis and their biological activities

Phytochemical research of two Tolpis species, T. proustii and T. lagopoda, led to the isolation of three new compounds: 30-chloro-3β-acetoxy-22α-hydroxyl-20(21)- taraxastene (1), 3β,22α-diacetoxy-30-ethoxy-20(21)-taraxastene (2) and 3β,28-dihydroxy11α-hydroperoxy-12-ursene (3). The structures of the new compounds were elucidated by means of extensive IR, NMR, and MS data and by comparison of data reported in the literature. The in vitro antioxidant activities of the extracts were assessed by the DPPH and ABTS scavenging methods. The cytotoxicity of several known compounds and its derivatives was also assessed against human myeloid leukemia K-562 and K-562/ADR cell lines.This work was supported by a Grant from the Ministry of Science of Spain and Innovation and from the European Regional Development Fund (SAF2010-21380) to F.E, Instituto Canario de Investigación del Cáncer to F.L. and Agencia Canaria de Investigación, Innovación y Sociedad de la Información (FEDER) (C200801000174) to J.T. F.L. was supported by JAE-doctoral Program from the Ministerio de Ciencia e Innovación.Peer reviewe

Assessment of registration methods for thermal infrared and visible images for diabetic foot monitoring

This work presents a revision of four different registration methods for thermal infrared and visible images captured by a camera-based prototype for the remote monitoring of diabetic foot. This prototype uses low cost and off-the-shelf available sensors in thermal infrared and visible spectra. Four different methods (Geometric Optical Translation, Homography, Iterative Closest Point, and Affine transform with Gradient Descent) have been implemented and analyzed for the registration of images obtained from both sensors. All four algorithms´ performances were evaluated using the Simultaneous Truth and Performance Level Estimation (STAPLE) together with several overlap benchmarks as the Dice coefficient and the Jaccard index. The performance of the four methods has been analyzed with the subject at a fixed focal plane and also in the vicinity of this plane. The four registration algorithms provide suitable results both at the focal plane as well as outside of it within 50 mm margin. The obtained Dice coefficients are greater than 0.950 in all scenarios, well within the margins required for the application at hand. A discussion of the obtained results under different distances is presented along with an evaluation of its robustness under changing conditions.This research was funded by the IACTEC Technological Training program, grant number TF INNOVA 2016–2021

Valorization of Seaweed Wracks : Inclusion as Additive in Diets for Grass Carp (Ctenopharyngodon idella)

Macroalgae have been recently described as a potential ingredient for aquafeeds, exerting several physiological benefits. Grass carp (Ctenopharyngodon idella) is a freshwater species, which has been the major fish species produced in the world in the last years. In order to determine the potential use of macroalgal wracks in fish feeding, C. idella juveniles were fed with an extruded commercial diet (CD) or the CD supplemented with 7% of a wind dried-powder (1 mm) from either a multispecific macroalgal wrack (CD + MU7) or a monospecific macroalgal wrack (CD + MO7) obtained from Gran Canaria island (Spain) coasts. After 100 days of feeding, survival, fish weight, and body indexes were determined, and muscle, liver, and digestive tract samples were collected. The total antioxidant capacity of macroalgal wracks was analyzed by assesing the antioxidant defense response and digestive enzymes activity in fish. Finally, muscle proximate composition, lipid classes (LC), and fatty acid (FA) profiles were also studied. Our results suggest that dietary inclusion of macroalgal wracks does not have negative effects on growth, proximate, and lipid composition, antioxidative status, or digestive capacity of C. idella. In fact, both macroalgal wracks caused a general lower fat deposition, and the multispecific wrack enhanced catalase activity in the liver.This study was funded by the European Interreg Programme 2014-2020 (MACBIOBLUE; MAC/1.1b/086). FCT–Fundação para a Ciência e a Tecnologia and as applicable cofinanced by the FEDER within the PT2020 Partnership Agreement by funding the cE3c centre (UID/BIA/00329/2019).info:eu-repo/semantics/publishedVersio