Plane Wave Imaging for ultrasonic non-destructive testing: Generalization to multimodal imaging

Pre-printInternational audienceThis paper describes a new ultrasonic array imaging method for Non-Destructive Testing (NDT) which is derived from the medical Plane Wave Imaging (PWI) technique. The objective is to perform fast ultrasound imaging with high image quality. The approach is to transmit plane waves at several angles and to record the back-scattered signals with all the array elements. Focusing in receive is then achieved by coherent summations of the signals in every point of a region of interest. The medical PWI is generalized to immersion setups where water acts as a coupling medium and to multimodal (direct, half-skip modes) imaging in order to detect different types of defects (inclusions, porosities, cracks). This method is compared to the Total Focusing Method (TFM) which is the reference imaging technique in NDT. First, the two post-processing algorithms are described. Then experimental results with the array probe either in contact or in immersion are presented. A good agreement between the TFM and the PWI is observed, with three to ten times less transmissions required for the PWI

Multimodal Plane Wave Imaging for Non-destructive Testing

International audienceUltrasonic imaging with high frame rates is of great interest in Non-Destructive Testing (NDT) to perform fast inspections. In this communication, we propose a new fast imaging method for NDT which is derived from the medical Plane Wave Imaging (PWI). The PWI method is applied to immersion-testing configurations (plane or complex water/steel interface between the probe and the image area) and to different imaging modes (imaging with direct or half-skip wave paths) according to the type of defects (point-like or extended crack-types defects)

La macrografía como método de análisis de roturas en servicio. Caso práctico: camisas de cilindro

En este trabajo se analizan en profundidad tanto las características metalúrgicas (composición y estructura) como las geométricas (forma, anclaje, textura superficial, rugosidad), de las camisas de cilindro, así como la influencia de dichas características en la aparición de diversos tipos de fallos y/o un elevado consumo de aceite del motor.Los parámetros esenciales en las medidas de estas características son analizados a partir de la inspección macrográfica de la pieza. El fenómeno de cavitación, proceso de corrosión específico de materiales metálicos en contacto con líquidos, es estudiado en profundidad y su incidencia en el funcionamiento de las camisas de cilindro. Se proponen las características óptimas que debe tener una camisa de cilindro con el objetivo de evitar l a incidencia de fallos internosasí como la aparición de cavitación

Comparison of knowledge, attitudes and hand hygiene behavioral intention in medical and nursing students.

Introduction: Hand hygiene is crucial to prevent cross infection. Healthcare students are in a prime position to learn hand hygiene skills. The aim of this study was to analyze hand hygiene behavioral intentions of healthcare students before and after contact with the patient and to compare the knowledge of and attitude towards hand hygiene between medical and nursing students. Methods: In a descriptive survey research design, convenience selection of a sample of medical students (n=657) and nursing students (n=303) was done from modules taught by the Department of Preventive Medicine and Public Health in both Medicine and Nursing undergraduate degrees in four Spanish universities. The hand hygiene Questionnaire, a validated instrument to evaluate behavior, knowledge, and attitudes, was used. Results: A significantly lower percentage of students reported always or almost always carrying out hand hygiene before contact with the patient or invasive procedures in comparison to the percentage complying after contact with secretions or with the patient. Although hand hygiene knowledge appears acceptable, its importance is not sufficiently valued.Conclusions: There are deficiencies in behavioral intention, knowledge, and attitudes related to hand hygiene in medical and nursing students. Better results are observed among nursing students, especially those who have received specific training

Prenatal exposure to organochlorine pesticides and TSH status in newborns from Southern Spain

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Diseño de vivienda de adobe con revestimiento de esteras de totora para mejorar el confort térmico en el distrito de Ayacucho de la provincia de Huamanga del departamento de Ayacucho

En el Perú, las heladas se presentan entre los meses de mayo y setiembre. Este clima afecta principalmente a los habitantes de la sierra peruana como en el departamento de Ayacucho. En general, son los mismos quienes padecen enfermedades como la gripe. Esto se debe a la falta de viviendas que minimicen la pérdida de energía interna, ya que muchas veces, estas son construidas sin presentar un adecuado confort interno. Por ello, esta tesis se propone el revestimiento interior de las viviendas con esteras de totora para mejorar el confort térmico. En este sentido, se desarrollará con la fabricación de los adobes según la norma E.080. Posteriormente, se construirán dos viviendas prototipos con el adobe elaborado y una de ellas se revestirá internamente con esteras de totora. Después de esta etapa, se realizará un registro de las temperaturas para ambas viviendas por medio de un equipo. Seguidamente, se hará el cálculo de la conductividad térmica para las viviendas y se comparará sus resultados. Finalmente, como resultado, la conductividad térmica se redujo en un 55.40% en la vivienda revestida con esteras de totora en comparación a la vivienda sin revestimiento y la resistencia térmica incrementó en un 71.70% al ser revestida.In Peru, the phenomenon of frosts manifests itself between the months of May and September. This climatic condition primarily affects the inhabitants of the Peruvian highlands such as in the department of Ayacucho. Generally, it is the very same individuals who suffer from diseases such as the cold. This is due to the lack of housing that minimizes the loss of internal energy, as often, these are constructed without providing adequate comfort inside. Addressing this issue, the present thesis proposed the application of totora (cattail) reed mats as interior lining for houses to enhance thermal comfort. Therefore, the manufacturing of adobe bricks was developed according to the stipulations of standard E.080. Subsequently, two prototype houses were constructed with the produced adobe, and one of them was internally lined with totora reed mats. Once all this was done, the temperatures for both houses were taken using specialized equipment. Then, the thermal conductivity of the houses was calculated and their results were compared. Finally, the results revealed a 55.40% reduction in thermal conductivity for the house with the totora reed mat lining, compared to the house without any lining, and thermal resistance in the lined house increased by 71.70%.Trabajo de Suficiencia Profesiona

GO/rGO as reinforcing nanofiller in aramid fiber/epoxy resin composite systems

Compatibility between matrix and reinforcement plays an important role in final properties of composite materials, which is why many works are focused in modify- ing interfacial interactions between both components to achieve greater mechanical properties. In the present study, 0.3 wt% of GO/rGO particles are introduced in epoxy resin/aramid fiber composites to evaluate the capacity of GO/rGO as reinforcing fillers. XPS, SEM, TGA, tensile and flexural tests are utilized to characterize GO/rGO, aramid fiber, three epoxy resin matrix systems and all composites obtained. Enhancements of mechanical properties up to 80 % were achieved by combining digly- cidyl ether bisfenol A (DGEBA) + diglycidyl aniline (DGA) + m-xylendiamine matrix, aramid fiber reinforcement and GO/rGO.Postprint (published version

Educational data mining for tutoring support in Higher Education: a web-based tool case study in engineering degrees

This paper presents a web-based software tool for tutoring support of engineering students without any need of data scientist background for usage. This tool is focused on the analysis of students' performance, in terms of the observable scores and of the completion of their studies. For that purpose, it uses a data set that only contains features typically gathered by university administrations about the students, degrees and subjects. The web-based tool provides access to results from different analyses. Clustering and visualization in a low-dimensional representation of students' data help an analyst to discover patterns. The coordinated visualization of aggregated students' performance into histograms, which are automatically updated subject to custom filters set interactively by an analyst, can be used to facilitate the validation of hypotheses about a set of students. Classification of students already graduated over three performance levels using exploratory variables and early performance information is used to understand the degree of course-dependency of students' behavior at different degrees. The analysis of the impact of the student's explanatory variables and early performance in the graduation probability can lead to a better understanding of the causes of dropout. Preliminary experiments on data of the engineering students from the 6 institutions associated to this project were used to define the final implementation of the web-based tool. Preliminary results for classification and drop-out were acceptable since accuracies were higher than 90% in some cases. The usefulness of the tool is discussed with respect to the stated goals, showing its potential for the support of early profiling of students. Real data from engineering degrees of EU Higher Education institutions show the potential of the tool for managing high education and validate its applicability on real scenarios.This work was supported by the Erasmus+ Key Action 2 Strategic Partnerships KA203, funded by the European Commission, under Grant 2016-1-ES01-KA203-025452.info:eu-repo/semantics/publishedVersio

Nonylphenol and octylphenol in adipose tissue of women in Southern Spain

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