Morphology and Material Composition of the Mouthparts of Stromatium unicolor Olivier 1795 (Coleoptera: Cerambycidae) for Bionic Application

The novelty of this study is the deep analysis of the morphologic, geometric and mechanical performance of longhorn beetle larvae mouthparts. Furthermore, a metal nano identification of jaw reinforced parts was made. Background and Objectives: Analysis of insect mechanical properties has shown an important application in the develop of bionic technologies such as new materials, industrial machines and structural concepts. This study aims to determine the mechanical and geometric properties of longhorn beetle (Stromatium unicolor Olivier 1795) larvae mouthparts to improve the development of innovative cutting tools. In addition, this study obtains a nano identification of metals in the cuticle of the mouthparts, which will enable the development of new nontoxic and sustainable preservation agents against xylophagous insects based on nanoparticles. Materials and Methods: five third-larval-stage samples of Stromatium unicolor were used to study its mandible morphologic, geometric and mechanical properties. To this end, mouthparts were analyzed by several microscopic techniques using a scanning electron microscope, a stereomicroscope and an optical microscope. Composition analysis was performed using with two Analytical-Inca X-ray detectors, dispersive energy spectroscopy and dispersive wavelength spectroscopy. Results: The main geometric parameters of the insect jaw are the edge angle (β = 77.3°), maximum path depth of the insect (120 μm), length (800 µm) and mouthpart movement, which were identified and measured. The chemical analysis results of the jaw tissues shows the presence of zinc and manganese. Conclusions: The geometry and angles of the mouthparts can be applied in the fabrication of bionic self-sharpening cutting tools. Molecular compounds that form the reinforcing elements in the jaws can be used to develop wood preservatives based on nanometals and metal absorption and metabolism inhibitor

Design and validation of a scalable, reconfigurable and low-cost structural health monitoring system

Producción CientíficaThis paper presents the design, development and testing of a low-cost Structural Health Monitoring (SHM) system based on MEMS (Micro Electro-Mechanical Systems) triaxial accelerometers. A new control system composed by a myRIO platform, managed by specific LabVIEW software, has been developed. The LabVIEW software also computes the frequency response functions for the subsequent modal analysis. The proposed SHM system was validated by comparing the data measured by this set-up with a conventional SHM system based on piezoelectric accelerometers. After carrying out some validation tests, a high correlation can be appreciated in the behavior of both systems, being possible to conclude that the proposed system is sufficiently accurate and sensitive for operative purposes, apart from being significantly more affordable than the traditional one.Junta de Castilla y León y Fondo Europeo de Desarrollo Regional (FEDER) - (grant VA095P17 and VA228P20

Assessment of machine learning algorithm-based grading of Populus x euramericana I-214 structural sawn timber

The efficiency of visual grading standards applied to structural timber is often inappropriate, and timber properties are either under or over-graded. Although not included in the current UNE 56544 visual grading standard, machine learning algorithms represent a promising alternative to grade structural timber. The general aim of this research was to compare the performance of machine learning algorithms based on visual defects, non-destructive techniques and sawing systems (“cut type”) with UNE 56544:1997 visual grading in order to predict the qualifying efficiency of Populus x euramericana I-214 structural timber. Visual evaluation, ultrasound and vibrational non-destructive testing, and sawing systems register (radial, tangential and mixed) were applied to characterize 945 beams. In addition, in order to retrieve actual physical-mechanical values, density and static bending destructive testing (EN-408:2011 + A1:2012) was also carried out. Several machine learning algorithms were then used to grade the beams, and their predictive accuracy was compared with that of visual grading. To do so, three scenarios were considered: a first scenario in which only visual variables were used; a second scenario in which “cut type” variables were also included; and a third scenario in which additional non-destructive variables were considered. Results showed a poor level of performance of UNE 56544:1997, with an apparent mismatch between the strength values assigned for each visual grade (established by the EN 338 standard) and the actual values. On the opposite, all algorithms performed better than visual grading and may thus be deemed as promising timber strength grading tools.Junta de Castilla y León (project VA047A08

Efectos de las radiaciones electromagnéticas de la telefonía móvil sobre los insectos

Se presenta una revisión de estudios de laboratorio realizados exponiendo insectos a radiaciones electromagnéticas en el rango de las microondas, similares a las utilizadas por los sistemas de telefonía que se utilizan actualmente, y a campos electromagnéticos de baja frecuencia. Las microondas pulsadas y moduladas de la telefonía son un reciente contaminante ubicuo, cuyas consecuencias todavía no han podido ser evaluadas convenientemente. Los estudios realizados indican efectos sobre este grupo de fauna, con previsibles consecuencias sobre los ecosistemas. Se recomienda la realización de seguimientos y estudios en las proximidades de las estaciones base de telefonía, donde existen los niveles más elevados de contaminación electromagnética y se exponen algunas características técnicas que pueden ayudar a identificar las áreas más afectadas por la radiación

¿Pueden afectar las microondas pulsadas emitidas por las antenas de telefonía a los árboles y otros vegetales?

El despliegue de la telefonía sin cable, acontecido durante la última década en todo el mundo, ha elevado la contaminación electromagnética en el rango de las radiofrecuencias en varios órdenes de magnitud, sobre todo en los núcleos habitados. No se han previsto los efectos sobre los seres vivos especialmente sobre los que, por su inmovilidad o sedentarismo, o por su proximidad a las instalaciones, padecen una irradiación crónica de niveles elevados, que según algunos expertos en bioelectromagnetismo tienen efectos acumulativos. El bioelectromagnetismo es una disciplina científica minoritaria que ha despertado interés y experimentado un gran auge recientemente. Una gran mayoría de investigadores independientes reconocen los efectos no térmicos de estas ondas sobre los seres vivos, que todavía no están contemplados en la legislación española. Con niveles de densidad de potencia miles de millones de veces más bajos existe suficiente cobertura para que la telefonía móvil funcione

Dynamic tests performed on a set of timber beams subjected to the effect of a mass placed on one end

El presente conjunto de datos contiene datos experimentales asociados a unos ensayos dinámicos realizados sobre 12 vigas de madera de unos 5 metros de longitud en cuyo extremo se ubica una masa variable. Se plantean diversos escenarios para cada viga, cada uno con una cantidad de masa diferente que varía entre 0 y 1200 kg. El efecto perseguido es el equivalente a la acción de un muro que gravita sobre la viga y que supone una determinada condición de contorno a medio camino entre el apoyo simple y el empotramiento ideal. Los ensayos dinámicos se realizan mediante un martillo de impacto, con el que se aplica una fuerza conocida sobre un determinado punto de la viga, y se registra la respuesta en aceleraciones de diferentes puntos de la misma. Son estos registros de fuerza y aceleraciones los incluidos en este dataset. Se proporciona más información en el documento “info.pdf” incluido junto con los datos. // This dataset contains experimental data associated to a series of dynamic tests performed on a set of twelve 5-meter-long timber beams with an additional mass placed on one end. Several scenarios have been considered, with added masses ranging from 0 to 1200 kg, whose aim is to reproduce the effect of a wall supported by the beams which affects them similarly to a boundary condition (something between the simple support and the ideal clamping). The dynamic tests have been performed by means of an impact hammer, which helps to measure the applied force, and several accelerometers intended to measure the response of six points of the beam. The force and acceleration recordings are stored in several files, which are contained in this dataset. More information about the tests can be found in the attached file “info.pdf”.Universidad de Valladolid. Grupo de Investigación en Estructuras y Tecnología de la MaderaUniversidad de Valladolid. Grupo de Investigación de Procesado en ArrayUniversidad de Valladolid. Instituto de Tecnologías Avanzadas de la Producción (ITAP)Subvenciones del Programa de Apoyo a Proyectos de Investigación, Cofinanciadas por el Fondo Europeo de Desarrollo Regional (FEDER), al amparo de la orden de 5 de mayo de 2020, de la Consejería de Educación de la Junta de Castilla y León. Proyecto de investigación: VA228P20. Título: Monitorización y diagnóstico de la salud de las estructuras de madera en el Patrimonio cultural a partir de técnicas dinámicas de bajo coste (TSHMLowC4.0