Ballistic performance of aramid composite combat helmet for protection against small projectiles

This paper focuses on the ballistic performance of aramid composite combat helmet commonly worn by military and security corps, against small projectiles threat. We propose a numerical finite element model for aramid composite protections, considering a multi-layer architecture, able to predict its ballistic behaviour and damage extension. The aim is determining the minimum number of layers required for a correct protection against a given ballistic thread. The constitutive aramid behaviour has been calibrated by means of experimental tests with FSP (Fragment Simulate Projectiles) projectiles and steel spheres on aramid flat plates. Once calibrated, a predictive numerical model of the helmet against different small projectiles and impacted localisations was developed and compared with experimental tests performed in the real head protection. The results calculated for the absorbed impact energy by the helmet and the induced damage due to small projectiles at different impact location, are in good agreement with experimental results and postmortem helmet analysis, validating the proposed numerical model. The numerical model is thus validated for the design of optimized head protections based on aramid compositeThe authors acknowledge the Ministry of Economy and Competitiveness of Spain and the European Regional Development Fund, (FEDER) program under the Project RTC-2015-3887-8 and the Project DPI2017-88166-R for the financial support of the work

Estudio morfológico, isotópico y proteómico de la fauna del Pleistoceno y Holoceno de Cova dos Santos (Abadín, Lugo, NO España)

[Abstract] Cova dos Santos is a karstic cavity in Abadín (Lugo), in a hitherto unexplored area that may have been the natural route between the well-known Quaternary faunas of the Cantabrian Mountain Range and those located further south in Galicia, such as in the Serra do Courel. The surface surveys carried out during the topographic layout revealed the presence of deposits of bone remains, usually extremely fragmented, of medium and large vertebrates. Due to the nature of these remains, different molecular techniques (ZooMS, stable isotopes), radiocarbon dating, and morphological and metric analysis were used to characterise the remains present at the site. Combining these methods, it has been possible to identify different taxa such as Ursus speleaeus, Ursus arctos, Panthera pardus, Cervus elaphus, Rhinocerotidae, and to confirm the occupation of this cave since at least 43000 years ago calBP. The presence of domestic species, such as Ovis aries, Equus sp. and Gallus gallus, also shows the use of this cave in more recent times.[Resumen] Cova dos Santos es una cavidad kárstica en Abadín (Lugo), en una zona hasta ahora inexplorada que podría haber sido la ruta natural entre las conocidas faunas cuaternarias de la cordillera Cantábrica y las situadas más al sur de Galicia, como en la Serra do Courel. La prospección de superficie realizada durante los trabajos de trazado topográfico reveló la presencia de depósitos de restos óseos, generalmente muy fragmentados, pertenecientes a vertebrados de mediano y gran tamaño. Debido al carácter de estos restos, se emplearon distintas técnicas moleculares (ZooMS, isótopos estables), dataciones por radiocarbono, y análisis morfológico y métrico para poder caracterizar los restos presentes en el yacimiento. Combinando estos métodos, se han podido identificar distintos taxones como Ursus speleaeus, Ursus arctos, Panthera pardus, Cervus elaphus, Rhinocerotidae, y constatar la ocupación de esta cueva desde hace al menos 43.000 años calBP. La presencia de especies domésticas, como Ovis aries, Equus sp. o Gallus gallus, también pone de manifiesto el uso de esta cavidad en épocas más recientes.This research was supported by financial assistance from the Sociedad Española de Paleontología ID AJISEP-2019-07121 and funds from the Instituto Universitario de Xeoloxía of the UDC. A. García-Vázquez is supported by a postdoctoral ICUB Fellowship for Young Researchers of the University of BucharestSociedad Española de Paleontología; AJISEP-2019-0712

Usefulness of the Hybrid RFR-FFR Approach: Results of a Prospective and Multicenter Analysis of Diagnostic Agreement between RFR and FFR—The RECOPA (REsting Full-Cycle Ratio Comparation versus Fractional Flow Reserve (A Prospective Validation)) Study

Cardiologia; Estudi fisiològic; EspanyaCardiología; Estudio fisiológico; EspañaCardiology; Physiological study; SpainBackground. The resting full‐cycle ratio (RFR) is a novel resting index which in contrast to the gold standard (fractional flow reserve (FFR)) does not require maximum hyperemia induction. The objectives of this study were to evaluate the agreement between RFR and FFR with the currently recommended thresholds and to design a hybrid RFR-FFR ischemia detection strategy, allowing a reduction of coronary vasodilator use. Materials and Methods. Patients subjected to invasive physiological study in 9 Spanish centers were prospectively recruited between April 2019 and March 2020. Sensitivity and specificity studies were made to assess diagnostic accuracy between the recommended levels of RFR ≤0.89 and FFR ≤0.80 (primary objective) and to determine the RFR “grey zone” in order to define a hybrid strategy with FFR affording 95% global agreement compared with FFR alone (secondary objective). Results. A total of 380 lesions were evaluated in 311 patients. Significant correlation was observed (R2 = 0.81; ) between the two techniques, with 79% agreement between RFR ≤ 0.89 and FFR ≤ 0.80 (positive predictive value, 68%, and negative predictive value, 80%). The hybrid RFR-FFR strategy, administering only adenosine in the “grey zone” (RFR: 0.86 to 0.92), exhibited an agreement of over 95% with FFR, with high predictive values (positive predictive value, 91%, and negative predictive value, 92%), reducing the need for vasodilators by 58%. Conclusions. Dichotomous agreement between RFR and FFR with the recommended thresholds is significant but limited. The adoption of a hybrid RFR-FFR strategy affords very high agreement, with minimization of vasodilator use

Tecnologías para la seguridad y su aplicación en la formación superior de los futuros oficiales de la Guardia Civil

El trabajo presenta la metodología empleada por el Centro Universitario de la Guardia Civil (CUGC) y la Universidad Carlos III de Madrid (UC3M) para el desarrollo de Trabajos Fin de Grado (TFG) enfocados a la aplicación educacional en defensa y seguridad. Los resultados presentados son desarrollados por los alumnos de cuarto curso en el Grado en Ingeniería de la Seguridad. El conocimiento desarrollado en el aspecto de la seguridad y el uso de nuevas herramientas numéricas son de gran utilidad para los futuros oficiales de la Guardia Civil. La principal contribución de este artículo es mostrar la heterogeneidad de los trabajos realizados, destacando el uso de herramientas informáticas para prevención, diseño y mejora de los dispositivos de seguridad y protección de las libertades de las personas. El uso de este tipo de herramientas aún no ha sido suficientemente utilizado a pesar de las amplias posibilidades que ofrece en el campo de la seguridad. En este documento se destacan los principales TFG destinados a la seguridad física así como al análisis de la seguridad empleando dispositivos tecnológicos: móviles, aviones no tripulados, material técnico y especializado para incendios estructurales.Los autores quieren agradecer la financiación recibida del Ministerio de Economía y Competitividad a través de los Proyectos RTC-2015-3887-8 y DPI2011-23191 en el Programa Estatal de Investigación, Desarrollo e Innovación Orientada a los Retos de la Sociedad, en el marco del Plan Estatal de Investigación Científica y Técnica y de Innovación 2013-2016

Numerical analysis of the ballistic behaviour of Kevlar® composite under impact of double-nosed stepped cylindrical projectiles

This paper focuses on the numerical analysis of the ballistic performance of Kevlar ®-29 under impact of different doublenosed stepped cylindrical projectiles. Numerical modelling based on finite element method was carried out in order to predict the failure mode of the target as well as the ballistic limit. A detailed analysis of the ballistic limit, failure mode and deformation of the targets due to impact of double-nosed projectiles was developed, discussed and compared with those involved in penetration of single-nosed flat and conical projectiles. Significant influence of the projectile geometry was demonstrated: the lowest ballistic limit was obtained with the conical–conical nose shape projectiles.The authors acknowledge the financial support for the work to the Ministry of Economy and Competitiveness of Spain under the Project RTC-2015-3887-8

Design and implementation of a VTOL flight transition mechanism and development of a mathematical model for a tilt rotor UAV

In the last decade, the interest in the development of unmanned aerial vehicles and the implementation of different flight topologies have been justified mainly by a wide range of applications, both military and civil. The current work can be used for educational purposes and we present two approaches in this area.CONACYT – Consejo Nacional de Ciencia y TecnologíaPROCIENCI

Determinants of Higher Mortality at Six Months in Patients with Hip Fracture: A Retrospective Study

Hip fracture is a pathology with high mortality, but the lack of a universal adaptation of the factors associated with death makes it difficult to predict risk and implement prevention in this group. This study aimed to identify the factors that determine a higher mortality at six months following hip fracture

Firm and industry effects on small, medium-sized and large firms’ performance

This paper examines whether or not the relative importance of the firm and industry effects in explaining performance variations is the same regardless of the firm size. In relation to size, we think that there has been particular neglect of studying medium-sized firms separately from SMEs in general. That is why we study separately large, medium-sized and small firms. We also contribute to knowledge on the firm-industry debate testing empirically both effects distinguishing the firms by size according to a standard classification in the EU. Our results show that the performances of large and small firms are mainly explained by the firm effect, albeit for different reasons, while the performance of medium-sized firms is explained primarily by the industry effect

Modelo numérico de flujo subterráneo para una cuenca endorréica en ambiente árido: Salar de Pipanaco (Catamarca, Argentina)

Se ha desarrollado un modelo regional de flujo de agua subterránea para la cuenca endorreica del Salar de Pipanaco (Catamarca, NOA Argentina). El modelo se realizó en condiciones estacionarias y transitorias para el periodo 1995-2015 bajo dos hipótesis de funcionamiento: a) con descarga del sistema por evapotranspiración, y b) adicionando al anterior una vía preferente de descarga por fracturas, consistente con el hecho de que se trata de una cuenca tectónica. En ambos casos se ha zonificado en 14 áreas de permeabilidad, 4 de vegetación con distinto poder evaporativo, y 8 de bombeo. Los resultados obtenidos muestran unas conductividades hidráulicas calibradas entre 1.7 y 55.9 m/d, coherentes con la litología y con resultados en ensayos de bombeo, con errores en las medidas de niveles inferiores a 5 m. El balance de masas muestra un sistema sobreexplotado incapaz de mantener sus reservas de aguas subterráneas. Las dos hipótesis simuladas son plausibles, siendo probable que se alternen los dos mecanismos de salida de agua del sistema.A regional groundwater flow model has been developed for the Salar de Pipanaco (Catamarca, NE Argentina). The model was made under steady and transient states, the last one for the period 1995-2015, based on two hypotheses: a) the evapotranspiration as the main discharge mechanism in the system, and b) an additional preferential discharge through regional fault zones. In both cases, the aquifer has been divided into 14 permeability areas, 4 vegetation areas with different evaporative capacity, and 8 pumping areas. The results indicate that the calibrated hydraulic conductivities ranges from 1.7 to 55.9 m/d, and those ones are consistent with the lithology and local groundwater pumping tests. The differences between measured and calculated piezometric levels are less than 5 m. The water budget shows an overdrawn aquifer unable to retain its storage. The two previous hypothesis are likely, and probably both mechanisms occur in an alternately way.Publicado en: García, R. y Mariño, E. (Eds): Calidad del Agua Subterránea: Actas IX Congreso Argentino de Hidrogeología y VII Seminario Hispano-Latinoamericano Sobre Temas Actuales de la Hidrología Subterránea. Editorial Científica Universitaria UNCA. ISBN 978-987-661-222-