1,204 research outputs found

    A further study of the kinetics of recrystallization and grain growth of cold rolled TWIP steel

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    Over last decades, the twinning - induced plasticity Fe-Mn-C (TWIP) steels have been the focus on huge amount of research works due to their prominent strength – ductility compounding which develops from the occurrence of extended mechanical twinning during plastic deformation under mechanical loads (Grässel and Frommeyer, 1998; Frommeyer et al., 2000; Cornette et al., 2005; Scott et al., 2006; Bouaziz et al., 2008; Hamada et al., 2010; Bouaziz et al., 2011; De Cooman et al., 2011; Galán et al., 2012; Gil Sevillano and De las Cuevas, 2012; Chen et al., 2013; De las Cuevas et al., 2014; Ghasri-Khouzani and McDermid, 2015; Pierce et al., 2015; De las Cuevas and Gil Sevillano, 2017). In TWIP steels, the fully austenitic microstructure can be retained by means of high level alloying with elements such as Mn, Al and Si. Al and Si are mainly used to adjust the magnitude of the stacking fault energy, gSFE, of austenite (Frommeyer et al., 2000). Furthermore, they also strengthen the steel by solid solution hardening and stabilize austenite owing to their ability of slowing down the precipitation of carbides, especially cementite, leaving more carbon available for the enrichment of austenite (Leslie and Rauch, 1978)

    Time Series

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    This paper first shows that survey-based expectations (SBE) outperform standard time series models in U.S. quarterly inflation out-of-sample prediction and that the term structure of survey-based inflation forecasts has predictive power over the path of future inflation changes. It then proposes some empirical explanations for the forecasting success of survey-based inflation expectations. We show that SBE pool a large amount of heterogeneous information on inflation expectations and react more flexibly and accurately to macro conditions both contemporaneously and dynamically. We illustrate the flexibility of SBE forecasts in the context of the recent financial crisis

    Bot’n roll robotic kit as a learning tool for youngsters

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    Activities involving robotics, projecting assembling and programming robots are in essence hands-on and inquiry-based activities leading to an effective learning of different aspects of science and technology among others. Different approaches have being used to introduce robotics in the education of young children. In this communication we will present an approach that in an inquiry based science education, IBSE, perspective, uses an informal environment to introduced robotics, as well as a range of other science and technology, concepts and competencies to young students. Many youngsters are getting interested on general technology and the robotics field in particular. Even though their knowledge is very basic they are very enthusiastic and willing to learn quickly. Most robotics events consist of competitions, and that means the youngsters still need guidance by professionals. RoboParty is a different educational robotics event that teaches the participants, with IBSE hands-on techniques, how to build a robot from scratch to program it and in the end they keep the robot they built for themselves for further exploration. Such robot to be built by the young children for the first time needs to be very easy and with a friendly programming language. The Bot’n Roll robotics kit was developed specifically for the RoboParty event, and has since then been improved with more sensors and actuators, which are simple to built and easy to use. The Bot’n Roll robot family launched recently another more complex robot that uses omnidirectional wheels and that can be used on other robotic competitions like world known RoboCup. This paper describes also the Bot’n Roll robots and show how they are built, bearing in mind that these robots were developed for youngsters who never worked with robotics

    Efectos garrapaticidas de algunos aceites esenciales

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    Soluciones acuo-etanólicas de aceites esenciales de Lippia (3 quimiotipos), Schinus molle, Tagetes, Lavandina (dos quimiotipos), Hisopo, Romero y Ciprés, fueron sometidas a ensayos in Vitro para evaluar sus efectos sobre le supervivencia y reproducción de las garrapata Rhipicephalus (Boophilus) microplus. Los aceites de Lippia, Tagetes e Hisopo mostraron buenos niveles de inhibición de la oviposición y de mortalidad superiores al 50%, a una concentración del 1%; no obstante, a concentraciones menores (0.5 y 0.1%) los resultados fueron inferiores. Especialmente activos fueron los aceites de varios quimiotipos de Lippia, que sorpresivamente mantuvieron niveles similares de actividad, lo cual indica un efecto sinergista o la presencia de una sustancia muy activa a concentraciones muy pequeñasPublishe

    Testosterone recovery after androgen deprivation therapy in prostate cancer: building a predictive model

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    Purpose: To analyze the variability, associated actors, and the design of nomograms for individualized testosterone recovery after cessation of androgen deprivation therapy (ADT). Materials and Methods: A longitudinal study was carried out with 208 patients in the period 2003 to 2019. Castrated and normogonadic testosterone levels were defined as 0.5 and 3.5 ng/mL, respectively. The cumulative incidence curve described the recovery of testosterone. Univariate and multivariate analyzes were performed to predict testosterone recovery with candidate prognostic factors prostate-specific antigen at diagnosis, clinical stage, Gleason score from biopsy, age at cessation of ADT, duration of ADT, primary therapy and use of LHRH (luteinizing hormone-releasing hormone) agonists. Results: The median follow-up duration in the study was 80 months (interquartile range, 49–99 mo). Twenty-five percent and 81% of patients did not recover the castrate and normogonadic levels, respectively. Duration of ADT and age at ADT cessation were significant predictors of testosterone recovery. We built two nomograms for testosterone recovery at 12, 24, 36, and 60 months. The castration recovery model had good calibration. The C-index was 0.677, with area under the receiver operating characteristic curve (AUC-ROC) of 0.736, 0.783, 0.782, and 0.780 at 12, 24, 36, and 60 months, respectively. The normogonadic recovery model overestimated the higher values of probability of recovery. The Cindex was 0.683, with AUC values of 0.812, 0.711, 0.708 and 0.693 at 12, 24, 36, and 60 months, respectively. Conclusions: Depending on the age of the patient and the length of treatment, clinicians may stop ADT and the castrated testosterone level will be maintained or, if the course of treatment has been short, we can estimate if it will return to normogonadic levels

    Pinus halepensis afforestations and ecosystem restoration under semiarid conditions

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    En la segunda mitad del siglo XX se llevaron a cabo extensas repoblaciones en el SE de la Península Ibérica utilizando casi exclusivamente el pino carrasco (Pinus halepensis). El objetivo de las mismas era recuperar una cierta cubierta arbórea, desaparecida como consecuencia de diferentes usos y perturbaciones. Pese a su magnitud y a la sensibilidad de estas zonas a la desertificación, hasta la fecha no disponemos de una revisión exhaustiva de las consecuencias de estas repoblaciones y una evaluación objetiva del éxito conseguido en la restauración de estos ecosistemas. Esta revisión sería muy útil para poder desarrollar una gestión adaptativa de estos ecosistemas, y con ello optimizar los recursos asignados a su restauración. En este trabajo hemos recopilado información propia y bibliográfica sobre estas cuestiones, tratando de extraer conclusiones y de identificar cuestiones aún no solucionadas.Aleppo pine (Pinus halepensis) has been extensively used for the afforestation in SE Spain during the second half of the XXth century. The main objectives of these plantations were to increase plant protective cover and to regulate hydrological cycles. Despite the magnitude of these interventions and the sensitivity of this area to desertification, the ecological consequences of these plantations and the degree of success in restoring ecosystem integrity has not been fully evaluated. An integrated study could be very helpful to develop an adaptive management of these areas, and to optimise resources allocation. Here we review available information on the effect of P. halepensis afforestations under semiarid conditions, and identify the main lacks of knowledge.Esta revisión ha sido posible gracias a la financiación recibida a través del proyecto FANCB (Ministerio de Ciencia y Tecnología y FEDER; REN2001-0424-C02-02 / GLO)

    Determination of toxic elements (mercury, cadmium, lead, tin and arsenic) in fish and shellfish samples. Risk assessment for the consumers

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    The authors would gratefully like to acknowledge the financial support given by Fondo de Investigaciones Sanitarias (reference PI10/00527). They are also grateful to the Spanish Ministry of Education, Culture and Sport for awarding Pablo Olmedo a FPU predoctoral fellowship (reference AP2009-0534) to achieve his PhD degree in the context of this research project.Although fish intake has potential health benefits, the presence of metal contamination in seafood has raised public health concerns. In this study, levels of mercury, cadmium, lead, tin and arsenic have been determined in fresh, canned and frozen fish and shellfish products and compared with the maximum levels currently in force. In a further step, potential human health risks for the consumers were assessed. A total of 485 samples of the 43 most frequently consumed fish and shellfish species in Andalusia (Southern Spain) were analyzed for their toxic elements content. High mercury concentrations were found in some predatory species (blue shark, cat shark, swordfish and tuna), although they were below the regulatory maximum levels. In the case of cadmium, bivalve mollusks such as canned clams and mussels presented higher concentrations than fish, but almost none of the samples analyzed exceeded the maximum levels. Lead concentrations were almost negligible with the exception of frozen common sole, which showed median levels above the legal limit. Tin levels in canned products were far below the maximum regulatory limit, indicating that no significant tin was transferred from the can. Arsenic concentrations were higher in crustaceans such as fresh and frozen shrimps. The risk assessment performed indicated that fish and shellfish products were safe for the average consumer, although a potential risk cannot be dismissed for regular or excessive consumers of particular fish species, such as tuna, swordfish, blue shark and cat shark (for mercury) and common sole (for lead).Instituto de Salud Carlos III PI10/00527Spanish Ministry of Education, Culture and Sport AP2009-053
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