Improving elevation resolution in phased-array inspections for NDT

The Phased Array Ultrasonic Technique (PAUT) offers great advantages over the conventional ultrasound technique (UT), particularly because of beam focusing, beam steering and electronic scanning capabilities. However, the 2D images obtained have usually low resolution in the direction perpendicular to the array elements, which limits the inspection quality of large components by mechanical scanning. This paper describes a novel approach to improve image quality in these situations, by combining three ultrasonic techniques: Phased Array with dynamic depth focusing in reception, Synthetic Aperture Focusing Technique (SAFT) and Phase Coherence Imaging (PCI). To be applied with conventional NDT arrays (1D and non-focused in elevation) a special mask to produce a wide beam in the movement direction was designed and analysed by simulation and experimentally. Then, the imaging algorithm is presented and validated by the inspection of test samples. The obtained images quality is comparable to that obtained with an equivalent matrix array, but using conventional NDT arrays and equipments, and implemented in real time.Fil: Brizuela, Jose David. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Camacho, J.. Consejo Superior de Investigaciones Científicas; EspañaFil: Cosarinsky, Guillermo Gerardo. Comisión Nacional de Energía Atómica; ArgentinaFil: Iriarte, Juan Manuel. Comisión Nacional de Energía Atómica; ArgentinaFil: Cruza, Jorge F.. Consejo Superior de Investigaciones Científicas; Españ

Using multicomponent recycled electronic waste alloys to produce high entropy alloys

The amount of electronic waste (e-waste) recycled worldwide is less than 20% of the total amount produced. In a world where the need for critical and strategic metals is increasing almost exponentially, it is unacceptable that tons of these elements remain unrecycled. One of the causes of this low level of recycling is that recycling is based on an expensive and complex selective sorting of metals. Extracting all metals simultaneously is much simpler and if this were done, it would significantly increase the recycling rate. Meanwhile, it was demonstrated that high entropy alloys (HEAs), which are in great demand in applications where very high performance is required, can be made from mixtures of complex alloys, hence reducing their dependence on pure critical metals. Here, we show that it is possible to obtain competitive HEAs from complex alloy mixtures corresponding to typical electronic waste compositions, combining two needs of high interest in our society, namely: to increase the level of recycling of electronic waste and the possibility of developing high-performance HEAs without the need of using critical and/or strategic metals. To validate our hypothesis that e-waste can be used to produce competitive HEAs, we propose an alloy design strategy combining computational thermodynamics (CalPhaD) exploration of phase diagrams and phenomenological criteria for HEA design based on thermodynamic and structural parameters. A shortlist of selected compositions are then fabricated by arc melting ensuring compositional homogeneity of such complex alloys and, finally, characterised microstructurally, using electron microscopy and diffraction analysis, and mechanically, using hardness testing

A quantitative study of modern pollen-vegetation relationships in southern Brazil's Araucaria forest

Southern Brazil's highland Araucaria forest is ancient, diverse and unique, but its future is under significant threat from 20th Century habitat loss and 21st Century climate change. Palaeoecological studies have revealed that it expanded rapidly over highland grasslands around 1,000 years ago, but whether this expansion was caused by human land use or climate change has been a topic of considerable debate. Discriminating between these potential drivers has so far not been possible with fossil pollen, however, as the palynological representation of floristic and structural differences in Araucaria forest remains poorly understood. Here, we address this shortcoming using modern pollen rain from moss polsters and vegetation surveys in forest areas with minimal current human disturbance. We show that forest plots with evident structural differences lack consistent differences in their floristic composition and cannot be reliably distinguished by their pollen spectra. We quantify pollen-vegetation relationships for 27 key tree genera of Araucaria forest, showing that, despite significant intra-taxon variability, 22 of these are under-represented or absent in the pollen record. These palynologically under-represented and silent taxa include many of the forest’s most ecologically important tree species, with only Araucaria, Lamanonia, Podocarpus, Myrsine and Clethra being more abundant in the pollen rain than vegetation. Our results suggest that subtle structural changes in Araucaria forest, as well as moderate to significant floristic changes, may not be clearly distinguished in fossil pollen records -- an important limitation when attempting to identify past human and climatic impacts on Araucaria forest via pollen analysis. Key words: Araucaria forest, pollen, moss polsters, modern analogues, human impac

Relevance evaluation of engineering masters program in Peru

In a context of mass higher education, it is necessary to ensure not only quality but also the relevance of engineering master's programs, namely the appropriateness of the objectives and outcomes to the needs and interests of the program beneficiaries. After a literature review we analyzed the evaluation models of three organizations in Peru: the Board of Evaluation, Accreditation and Certification of the University Education Quality CONEAU, the Institute of Quality and Accreditation of Computing, Engineering and Technology - ICACIT and the Pontificia Universidad Catolica del Peru. The result of this study is a model for relevance evaluation for an engineering master¿s program in Peru

Una propuesta de desarrollo regional: asociaciones a través de proyectos conjuntos de cooperación

En Perú se han desplegado diferentes intentos de modelos de regionalización, habiendo partido desde una simple demarcación territorial, sin identificación de competencias que configuren territorios autogestionarios. Subyacente a este modelo, se han identificado claras deficiencias de competencias institucionales conducentes a un modelo sustentable de desarrollo. Además de las deficiencias mencionadas, no se han reflejado intenciones de articular fortalezas-competencias entre regiones, que permitan a través de sinergias, promover programas y proyectos de cooperación al desarrollo. La propuesta a abordar, apunta de reunir pueblos-mancomunidades, bajo una visión de complementación de competencias, a través de la cual desarrollar proyectos colaborativos que permitan explotar los recursos de dichas mancomunidades con ventajas competitivas propias. La propuesta en mención parte de identificación de fortalezas y debilidades sobre poblados en Perú, con una visión de complementariedad, la cual permita configurar un conjunto de fortalezas sobre las cuales desarrollar proyectos conducentes a un desarrollo sustentable

Nigeria, la doble cara del gigante africano

Muchas veces nos explican la falacia de que cualquier país en vía de desarrollo puede prosperar si se posee los recursos suficientes y si se aplican las políticas necesarias, pero, en la realidad esto no es tan fácil como parece. Por ello, este trabajo va a tratar de Nigeria, un país considerado como el gigante de África debido a que es casi el doble de grande que España en hectáreas y posee una gran cantidad de recursos naturales. Además, en los últimos años ha obtenido un gran crecimiento económico y contiene una de las más grandes reservas de petróleo del mundo. A pesar de todo esto, los beneficios económicos que se consiguen no se ven reflejados en el bienestar de la sociedad. Nigeria, actualmente, está sumida en el caos y gran parte de la culpa la tiene que se haya encontrado grandes cantidades de petróleo en el país. Por consiguiente, este trabajo hace un análisis general de Nigeria e intenta dar una explicación a esta realidad.<br /

Os vetores e a saúde pública no atual cenário de alterações climáticas: uma abordagem ao controlo de vectores

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Genetic and morpho-physiological differentiation in a limpet population across an intertidal gradient

Marine organism adaptive capacity to different environmental conditions is a research priority to understand what conditions are important in structuring the spatial distribution of natural populations. In this context, this study evaluates whether potential differences in Siphonaria lessonii morphology (size and shell shape) and physiology (water loss regulation) at different shore heights are linked to genetically distinguishable individuals. To achieve this goal, we compared size-frequency distribution, morphometric, and genetic data (ISSR-PCR technique) of S. lessonii from the upper, middle and lower shore. We complemented these field samplings with laboratory experiments on water loss and mortality. Genetic analysis showed different genetic composition for individuals from the upper and lower shore. This pattern was accompanied by morpho-physiological variations: the upper shore had fewer small limpets, lower shell shape dispersion (with a morphotype characterized by a higher shell), and less water loss and mortality related to air exposure than the lower shore. The results reported herein support the idea that the extreme and unpredictable conditions of the upper shore may impose strong selection pressure on its inhabitants, leading to considerable morpho-physiological differentiation consistent with different genetic composition. This probably plays an important role in structuring the spatial distribution of natural S. lessonii populations with a possible effect on size-structure distribution.Fil: Nuñez, Jesus Dario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Fernandez Iriarte, Pedro Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Ocampo, Emiliano Hernan. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Madrid, Enrique. Universidad Nacional de Mar del Plata; ArgentinaFil: Cledón, Maximiliano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentin

Population genetic structure and body shape assessment of Pagrus pagrus (Linnaeus, 1758) (Perciformes: Sparidae) from the Buenos Aires coast of the Argentine Sea

El estudio comprende un análisis de la variación morfológica y genética del besugo Pagrus pagrus, comparando dos áreas principales de concentración, una Norte (35ºS - 38ºS) y otra Sur (39ºS - 41ºS) en la costa bonaerense del Mar Argentino. La caracterización de la forma del cuerpo mostró dos morfotipos diferenciados significativamente (Wilks´ Lambda= 0.224, P<0.001), presentando en el área Norte una mayor altura en la parte media del cuerpo y una menor longitud y altura del pedúnculo caudal que los correspondientes al área Sur. Las áreas Norte y Sur no presentaron diferencias genéticas significativas, tanto para la región control del ADN mitocondrial como para los loci microsatélites, revelando que P. pagrus no está estructurado genéticamente. Sin embargo, los individuos de estas áreas no deberían manejarse como un mismo grupo ya que presentan distintas características de historia de vida, responsables de la diferenciación morfológica. La presencia de dos sitios de cría con características distintivas, definiría para P. pagrus dos stocks en la costa bonaerense.This study highlights the analysis of the morphological and genetic variation of the common sea bream Pagrus pagrus, and compares its two main areas of concentration: the northern (35ºS - 38ºS) and the southern areas (39ºS - 41ºS) of the Buenos Aires coast of the Argentine Sea. Body shape characterization presented two significantly different morphotypes (Wilks' Lambda=0.224, P<0.001). Northern individuals displayed a higher middle area while southern ones were smaller and their caudal peduncle was shorter. The northern and southern areas did not yield significant genetic differences either with the control region or the microsatellite loci, revealing that P. pagrus is not genetically structured. However, individuals from these areas should not be managed as a single group since they display distinct life history traits, responsible for morphological differentiation. The presence of two spawning areas with distinctive characteristics would define two stocks of P. pagrus from the Buenos Aires coast.Fil: Porrini, Leonardo Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Fernandez Iriarte, Pedro Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Iudica, Celia M.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Aristizabal Abud, Eddie Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Subsede Instituto Nacional de Investigación y Desarrollo Pesquero; Argentin