Dataset concerning the analytical approximation of the Ae3 temperature.

In this paper we present a new polynomial function for calculating the local phase transformation temperature (Ae3 ) between the austenite+ferrite and the fully austenitic phase fields during heating and cooling of steel:[Formula: see text] The dataset includes the terms of the function and the values for the polynomial coefficients for major alloying elements in steel. A short description of the approximation method used to derive and validate the coefficients has also been included. For discussion and application of this model, please refer to the full length article entitled "The role of aluminium in chemical and phase segregation in a TRIP-assisted dual phase steel" 10.1016/j.actamat.2016.05.046 (Ennis et al., 2016) [1]

Wind Turbine Failures - Tackling current Problems in Failure Data Analysis

The wind industry has been growing significantly over the past decades, resulting in a remarkable increase in installed wind power capacity. Turbine technologies are rapidly evolving in terms of complexity and size, and there is an urgent need for cost effective operation and maintenance (O&M) strategies. Especially unplanned downtime represents one of the main cost drivers of a modern wind farm. Here, reliability and failure prediction models can enable operators to apply preventive O&M strategies rather than corrective actions. In order to develop these models, the failure rates and downtimes of wind turbine (WT) components have to be understood profoundly. This paper is focused on tackling three of the main issues related to WT failure analyses. These are, the non-uniform data treatment, the scarcity of available failure analyses, and the lack of investigation on alternative data sources. For this, a modernised form of an existing WT taxonomy is introduced. Additionally, an extensive analysis of historical failure and downtime data of more than 4300 turbines is presented. Finally, the possibilities to encounter the lack of available failure data by complementing historical databases with Supervisory Control and Data Acquisition (SCADA) alarms are evaluated

SCADA alarms processing for wind turbine component failure detection

Wind turbine failure and downtime can often compromise the profitability of a wind farm due to their high impact on the operation and maintenance (O&M) costs. Early detection of failures can facilitate the changeover from corrective maintenance towards a pre- dictive approach. This paper presents a cost-effective methodology to combine various alarm analysis techniques, using data from the Supervisory Control and Data Acquisition (SCADA) system, in order to detect component failures. The approach categorises the alarms according to a reviewed taxonomy, turning overwhelming data into valuable information to assess component status. Then, different alarms analysis techniques are applied for two purposes: the evaluation of the SCADA alarm system capability to detect failures, and the investigation of the relation between components faults being followed by failure occurrences in others. Various case studies are presented and discussed. The study highlights the relationship between faulty behaviour in different components and between failures and adverse environmental conditions

Position-dependent shear-induced austenite-martensite transformation in double-notched TRIP and dual-phase steel samples

While earlier studies on transformation-induced-plasticity (TRIP) steels focused on the determination of the austenite-to-martensite decomposition in uniform deformation or thermal fields, the current research focuses on the determination of the local retained austenite-to-martensite transformation behaviour in an inhomogeneous yet carefully controlled shear-loaded region of double-notched TRIP and dual-phase (DP) steel samples. A detailed powder analysis has been performed to simultaneously monitor the evolution of the phase fraction and the changes in average carbon concentration of metastable austenite together with the local strain components in the constituent phases as a function of the macroscopic stress and location with respect to the shear band. The metastable retained austenite shows a mechanically induced martensitic transformation in the localized shear zone, which is accompanied by an increase in average carbon concentration of the remaining austenite due to a preferred transformation of the austenite grains with the lowest carbon concentration. At the later deformation stages the geometry of the shear test samples results in the development of an additional tensile component. The experimental strain field within the probed sample area is in good agreement with finite element calculations. The strain development observed in the low-alloyed TRIP steel with metastable austenite is compared with that of steels with the same chemical composition containing either no austenite (a DP grade) or stable retained austenite (a TRIP grade produced at a long bainitic holding time). The transformation of metastable austenite under shear is a complex interplay between the local microstructure and the evolving strain fields

On the use of high-frequency SCADA data for improved wind turbine performance monitoring

SCADA-based condition monitoring of wind turbines facilitates the move from costly corrective repairs towards more proactive maintenance strategies. In this work, we advocate the use of high-frequency SCADA data and quantile regression to build a cost effective performance monitoring tool. The benefits of the approach are demonstrated through the comparison between state-of-the-art deterministic power curve modelling techniques and the suggested probabilistic model. Detection capabilities are compared for low and high-frequency SCADA data, providing evidence for monitoring at higher resolutions. Operational data from healthy and faulty turbines are used to provide a practical example of usage with the proposed tool, effectively achieving the detection of an incipient gearbox malfunction at a time horizon of more than one month prior to the actual occurrence of the failure

On the effects of environmental conditions on wind turbine performance: an offshore case study

Monitoring wind turbine (WT) performance offers a means of identifying abnormal operation, but only if natural disturbances of the operating regime change can be excluded. WT performance monitoring usually relies on the analysis of operational power curves, generally based on data from the supervision control and data acquisition system. However, these curves do not reflect the source of variability, negatively affecting the capabilities for detecting WT abnormal performance. This work aims at understanding and quantifying changes in WT performance variability due to different environmental conditions during normal and wake-free operating conditions, based on an offshore case study. The magnitude of performance fluctuations is highly influenced by environmental conditions, being higher during high turbulence intensity and low wind shear conditions. The Taylor law, with small time windows, is suitable to describe them for low-mid winds in the absence of dedicated wind measurements, often not permanently available offshore, and could potentially result in more effective performance monitoring solutions. Nevertheless, the heteroskedastic nature of the power deviations negatively affects fitting possibilities. The results support the importance of using low data aggregation periods to understand the dynamics of WT performance

Open access to educational resources in energy and sustainability: Usability evaluation prototype for repositories

The purpose of this paper is to show a PhD dissertation research plan, which aims to assess whether the users’ experience of users to perform various tasks in an open access repository, increases by integrating Discovery Tools. The tasks to perform by the users are management and information design, dissemination and searches of open educational resources (OER) of sustainability energy. This research aims to develop a usability evaluation prototype which will offer new insights in the design of the information architecture. In the first stage, the criteria will be selected to measure the level of usability of the tasks to evaluate and develop the analysis of the current interactive design of the web repository. In the second stage, will consist of measure, once implemented the Discovery Tools in the web repository and check the usability level increase in relation with the criteria. In this paper you could find aspects as the motivations and the context in which it will develop this research, state of the art, hypothesis, research objectives, aspects of the methodology of the research, developed under the method of mixed layout, the current an expected contribution, the results and the validation and dissertation status. The results will contribute for detect new criteria and parameters for provide flexible interfaces, specifically for the web repositories, which are a part of the technological ecosystem of the scientific activity

The Tragical Comedy or Comical Tragedy of Mr. Punch: Análisis de un clásico en tres actos

[ES] Este trabajo tiene como objeto final abordar la revisión de la adaptación posmoderna de las aventuras y desventuras del cómico personaje de herencia italiana Pulcinella, que Neil Gaiman y Dave McKean llevaron a cabo en su obra titulada "The Tragical Comedy or Comical Tragedy of Mr. Punch" publicada por Vertigo en el año 1994. No obstante, esta investigación se sustenta en torno a tres aspectos básicos que serán considerados como cuantitativa y temáticamente equivalentes para su adecuada exposición y que, por tanto, serán tratados, respectivamente, como objeto central de estudio de cada uno de los capítulos que la componen. Así, el primer acto estará dedicado al estudio de la naturaleza del cómic, por ser este el medio en el que se desarrolla la citada pieza; el segundo girará en torno a los orígenes y la evolución de Mr. Punch, por ser este personaje el protagonista de la misma; y, finalmente, el tercer acto se dedicará a un análisis pormenorizado de "The Tragical..." así como el contexto artístico en el que esta novela gráfica ve la luz. Resulta necesario señalar que la obra de Gaiman y McKean es un trabajo mixto, en el que se mezclan literatura y artes gráficas, puesto que pretende emular lo más fielmente posible a las diferentes versiones impresas de la historia, la primera de las cuales data de 1828, eso sí aportando siempre la imaginería personal de los autores. Esta primera versión ya aunaba la transcripción del periodista John Payne Collier con las ilustraciones del caricaturista George Cruikshank, lo cual muestra un interés temprano no solo por la pervivencia de la pieza de guiñol, sino también por la alta capacidad de expresión y transmisión de la palabra escrita acompañada por imágenes. Asimismo, se subrayará que la obra de Gaiman y McKean nace como resultado de un proceso de hibridación total, ya que no solo parte del ámbito de la "commedia dell'arte" -forma teatral que solo ve cumplida su función catártica a través de la representación y ya es, en sí, una forma híbrida y permanentemente reactualizable de la literatura-, sino que a lo largo de su historia sufre adaptaciones a mundos o tiempos tan distintos como el guiñol o la novela gráfica y el Renacimiento o la Posmodernidad, manteniendo en todo momento su esencia y demostrando que se trata de un comportamiento humano válido en los contextos más variados

Frozen-hydrated chromatin from metaphase chromosomes has an interdigitated multilayer structure

Cryo-electron tomography and small-angle X-ray scattering were used to investigate the chromatin folding in metaphase chromosomes. The tomographic 3D reconstructions show that frozen-hydrated chromatin emanated from chromosomes is planar and forms multilayered plates. The layer thickness was measured accounting for the contrast transfer function fringes at the plate edges, yielding a width of similar to 7.5 nm, which is compatible with the dimensions of a monolayer of nucleosomes slightly tilted with respect to the layer surface. Individual nucleosomes are visible decorating distorted plates, but typical plates are very dense and nucleosomes are not identifiable as individual units, indicating that they are tightly packed. Two layers in contact are similar to 13 nm thick, which is thinner than the sum of two independent layers, suggesting that nucleosomes in the layers interdigitate. X-ray scattering of whole chromosomes shows a main scattering peak at similar to 6 nm, which can be correlated with the distance between layers and between interdigitating nucleosomes interacting through their faces. These observations support a model where compact chromosomes are composed of many chromatin layers stacked along the chromosome axis