Perforation mechanics of 2024 aluminium protective plates subjected to impact by different nose shapes of projectiles

This paper focuses on the mechanical behaviour of aluminium alloy 2024-T351 under impact loading. This study has been carried out combining experimental and numerical techniques. Firstly, experimental impact tests were conducted on plates of 4 mm of thickness covering impact velocities from 50 m/s to 200 m/s and varying the stress state through the projectile nose shape: conical, hemispherical and blunt. The mechanisms behind the perforation process were studied depending on the projectile configuration used by analyzing the associated failure modes and post-mortem deflection. Secondly, a numerical study of the mechanical behaviour of aluminium alloy 2024-T351 under impact loading was conducted. To this end, a three-dimensional model was developed in the finite element solver ABAQUS/Explicit. This model combines Lagrangian elements with Smoothed Particle Hydrodynamics (SPH) elements. A good correlation was obtained between numerical and experimental results in terms of residual and ballistic limit velocities

Model biopsychicalsocial in the syndromes of vertebral pain: implications for the protocolize

[Resumen] De forma tradicional el modelo biomédico ha predominado en la práctica asistencial. A diferencia de éste, el modelo biopsicosocial considera a la persona como un todo y hace énfasis sobre la función en lugar de centrarse exclusivamente en el alivio del dolor. En este sentido, la Fisioterapia para el tratamiento de los problemas de espalda, y en concreto para la cervicalgia, tiene que considerar, además del alivio del dolor, la cronicidad y la recurrencia como elementos a considerar en el diseño de actividades protocolizadas.[Abstract] In a traditional way the biomedical model has prevailed in the health care. Against it the biopsychicalsocial pattern considers to the person as a whole and it makes emphasis on the function instead of being centered exclusively in the relief of the pain. In this sense, Physiotheraphy for the treatment of the back problems and in this case for the neck pain, it has to consider besides the relief of the pain, the chronic and the new episodies like elements to consider in the design of protocolized activities

Small Renal Masses: Incidental Diagnosis, Clinical Symptoms, and Prognostic Factors

Introduction. The small renal masses (SRMs) have increased over the past two decades due to more liberal use of imaging techniques. SRMs have allowed discussions regarding their prognostic, diagnosis, and therapeutic approach. Materials and methods. Clinical presentation, incidental diagnosis, and prognosis factors of SRMs are discussed in this review. Results. SRMs are defined as lesions less than 4 cm in diameter. SRM could be benign, and most malignant SMRs are low stage and low grade. Clinical symptoms like hematuria are very rare, being diagnosed by chance (incidental) in most cases. Size, stage, and grade are still the most consistent prognosis factors in (RCC). An enhanced contrast SRM that grows during active surveillance is clearly malignant, and its aggressive potential increases in those greater than 3 cm. Clear cell carcinoma is the most frequent cellular type of malign SRM. Conclusions. Only some SRMs are benign. The great majority of malign SRMs have good prognosis (low stage and grade, no metastasis) with open or laparoscopic surgical treatment (nephron sparing techniques). Active surveillance is an accepted attitude in selected cases

Caracterización del proteoma de las envolturas interna y externa de cloroplasto de Pisum sativum

Comunicaciones a congreso

Genetic characterization of Carnivore Parvoviruses in Spanish wildlife reveals domestic dog and cat-related sequences

The impact of carnivore parvovirus infection on wild populations is not yet understood; disease signs are mainly developed in pups and assessing the health of litters in wild carnivores has big limitations. This study aims to shed light on the virus dynamics among wild carnivores thanks to the analysis of 213 samples collected between 1994 and 2013 in wild ecosystems from Spain. We determined the presence of carnivore parvovirus DNA by real‐time PCR and sequenced the vp2 gen from 22 positive samples to characterize the strains and to perform phylogenetic analysis. The presence of carnivore parvovirus DNA was confirmed in 18% of the samples, with a higher prevalence detected in wolves (Canis lupus signatus, 70%). Fourteen sequences belonging to nine wolves, three Eurasian badgers (Meles meles), a common genet (Genetta genetta) and a European wildcat (Felis silvestris) were classified as canine parvovirus 2c (CPV‐2c); five sequences from three wolves, a red fox (Vulpes vulpes) and a stone marten (Martes foina) as CPV‐2b; and three sequences from a badger, a genet and a stone marten as feline parvovirus (FPV). This was the first report of a wildcat infected with a canine strain. Sequences described in this study were identical or very close related to others previously found in domestic carnivores from distant countries, suggesting that cross‐species transmission takes place and that the parvovirus epidemiology in Spain, as elsewhere, could be influenced by global factors

Impact response of advance combat helmet pad systems

Combat helmets are designed to protect against ballistic threats and fragments of explosive devices. There are numerous types of helmet comfort foams available. However, pad systems have not been evaluated in combat helmets to understand to what extent they mitigate head accelerations. In this work, different pad systems are studied to analyze the ballistic performance of combat helmets using a Hybrid III dummy equipped with longitudinal accelerometers at the head and a neck simulator. The tests are conducted with 9 mm Full Metal Jacket (FMJ) projectiles according to the performance requirements III-A of the NIJ 0106.01 standard. This experimental methodology allows the evaluation of brain and neck injuries. The thicker bicomponent polyurethane foams and the honeycomb configuration provided the best results in terms of mitigating brain damage due to accelerations applying different criteria (PLA, WSTC, HIC). However, it was concluded that there is no cervical injury or cranial fracture risk for any of the cases studied.The authors acknowledge the Ministry of Economy and Competitiveness of Spain and the FEDER program under Projects DPI2017-88166-R and PID2020-118946RB-I00 for the financial support of the work. M. Rodriguez-Millan acknowledges the Spanish Ministry of Universities, the National Program for the Promotion of Talent, and its Employability in Research and Development and Innovation (R&D&I), National Mobility Subprogram of the National Plan for Scientific and Technical Research and Innovation 2021–2023, for the professor’s mobility program (PRX21/00329). It has to thank the funding for APC: Universidad Carlos III de Madrid (Read and Publish Agreement CRUECSIC 2023).Publicad

Rotating Convection in an Anisotropic System

We study the stability of patterns arising in rotating convection in weakly anisotropic systems using a modified Swift-Hohenberg equation. The anisotropy, either an endogenous characteristic of the system or induced by external forcing, can stabilize periodic rolls in the K\"uppers-Lortz chaotic regime. For the particular case of rotating convection with time-modulated rotation where recently, in experiment, chiral patterns have been observed in otherwise K\"uppers-Lortz-unstable regimes, we show how the underlying base-flow breaks the isotropy, thereby affecting the linear growth-rate of convection rolls in such a way as to stabilize spirals and targets. Throughout we compare analytical results to numerical simulations of the Swift-Hohenberg equation

Experimental and numerical analyses of ballistic resistance evaluation of combat helmet using Hybrid III headform

Combat helmets are the primary system for protecting the head against ballistic impacts. Generally, combat helmets have been evaluated using a ballistic plasticine head surrogate based on international standards. More realistic human head models have recently been introduced to assess combat helmet performance considering biomechanical requirements. In this work, the Hybrid III dummy head and neck has been introduced to evaluate the performance of the combat helmet against the ballistic impact of live ammunition at different impact locations, considering two different thicknesses of the padding system. A numerical model including a helmet and a Hybrid III head and neck, is developed and validated with our experimental data. The results reveal the influence of the location, where the rear impact leads to the highest risk of brain damage. The effect of pad thickness is closely related to the energy absorbed by the helmet, the backface deformation (BFD), the contact force and the acceleration measured on the head.The authors acknowledge the Ministry of Economy and Competitiveness of Spain and FEDER program under Project RTC-2015-3887-8 and Project DPI2017-88166-R for the financial support of the work. M Rodriguez-Millan acknowledges the Spanish Ministry of Universities, National Program for the Promotion of Talent and its Employability in R&D&I, National Mobility Subprogram of the National Plan for Scientific and Technical Research and Innovation 2021-2023, for the professor's mobility program (PRX21/00329)

Defect Chaos of Oscillating Hexagons in Rotating Convection

Using coupled Ginzburg-Landau equations, the dynamics of hexagonal patterns with broken chiral symmetry are investigated, as they appear in rotating non-Boussinesq or surface-tension-driven convection. We find that close to the secondary Hopf bifurcation to oscillating hexagons the dynamics are well described by a single complex Ginzburg-Landau equation (CGLE) coupled to the phases of the hexagonal pattern. At the bandcenter these equations reduce to the usual CGLE and the system exhibits defect chaos. Away from the bandcenter a transition to a frozen vortex state is found.Comment: 4 pages, 6 figures. Fig. 3a with lower resolution no