Effect of filler nature and content on the bituminous mastic behaviour under cyclic loads

The role of the filler in asphalt mixtures is particularly important because of its influence on mastic behaviour. The filler improves the resistance properties of bitumen against the action of traffic loads and temperature. However, the filler can also adversely affect bitumen in mastics excessively brittle and stiff due to inappropriate design. For these reasons, it is interesting to investigate the effect of filler type and content on mastic composition. This paper presents results from a strain sweep test applied to bituminous mastics prepared with different filler types and contents at several temperatures. The obtained stiffness modulus and failure strain results provide information to assess the fatigue behaviour of the analysed mastics.Peer ReviewedPostprint (author's final draft

A lower bound for the number of components of the moduli schemes of stable rank 2 vector bundles on projective 3-folds

Fix a smooth projective 3-fold X, c1, H ∈ Pic(X) with H ample, and d ∈ Z. Assume the existence of integers a, b with a ≠ 0 such that ac1 is numerically equivalent to bH. Let M(X, 2, c1, d, H) be the moduli scheme of H-stable rank 2 vector bundles, E, on X with c1(E) = c1 and c2(E) · H = d. Let m(X, 2, c1, d, H) be the number of its irreducible components. Then lim supd→ ∞m(X, 2, c1, d, H) = +∞

Enterococcus faecalis bacteremia: please do the echo

Infective endocarditis (IE) caused by Enterococcus faecalis (E. faecalis) is a disease of the elderly with an increasing incidence, often health-care associated and with in-hospital mortality rates around 10-20%. E. faecalis IE is notoriously challenging to diagnose due to unspecific symptoms, often presenting with a complex clinical picture with low-grade fever and only moderately elevated infectious parameters. In a newly published prospective multicenter study using echocardiography to screen E. faecalis bacteremia patients, we found an IE prevalence as high as 26%. The 344 included patients with E. faecalis bacteremia had a mean age of 74 (±12) years confirming that it is indeed a disease of the elderly. The key feature of the study was that echocardiography was performed in all patients including transesophageal echocardiography (TEE) in 74%. Transthoracic echocardiography (TTE) missed vegetations in half of the cases where TEE demonstrated vegetations, underlining the importance of TEE

Modelling the spatio-temporal evolution of H-3 in the waters of the River Tagus

Measurements of tritium specific activity levels and of temperatures in waters of the Torrejo´neTagus reservoir (Spain) showed that their radioactive characteristics were basically influenced by the radioactive liquid effluent from the Almaraz Nuclear Power Plant. This enters the Torrejo´neTagus reservoir via the Arrocampo cooling reservoir, which exchanges water with the first. We studied the temporal and spatial (in two dimensions) evolution of the mentioned parameters for years 1997 and 1998. The tritium levels were found to be significantly correlated with temperature. Two numerical models were constructed for a quantitative study of the tritium levels along Torrejo´n reservoir: a 1D model was used for the dispersion of tritium along the whole length of the reservoir, and a 2D depth-averaged model was used for a detailed study of the area where tritium is released into the reservoir. Both models solve the hydrodynamic equa tions, to obtain the currents induced by the exchanges of water between the reservoirs in the River Tagus and Arrocampo, and the advection/diffusion equation to calculate the dispersion of tritium. In general, the model results were in agreement with the experimental observationsJunta de Extremadura 2PR02A02

Structure of Extremely Nanosized and Confined In-O Species in Ordered Porous Materials

Perturbed-angular correlation, x-ray absorption, and small-angle x-ray scattering spectroscopies were suitably combined to elucidate the local structure of highly diluted and dispersed InOx species confined in porous of ZSM5 zeolite. These novel approach allow us to determined the structure of extremely nanosized In-O species exchanged inside the 10-atom-ring channel of the zeolite, and to quantify the amount of In2O3 crystallites deposited onto the external zeolite surface.Comment: 4 pages, 5 postscript figures, REVTEX4, published in Physical Review Letter

Predictors of the perceived risk of COVID-19 and adherence to confinement guidelines in the context of the COVID-19 pandemic

INTRODUCTION: Complete adherence to public health guidelines is essential to reduce the spread of COVID-19. Studies on the factors associated with increased/decreased adherence to these measures have the potential to inform public policies directed at increasing adherence, and thus helping to control the spread of the current pandemic. OBJECTIVES: This study aimed at assessing the demographic and psychosocial predictors of the perceived risk of the COVID-19 and adherence to confinement guidelines during the first mandatory lockdown in Portugal. METHODS: A convenience sample of 430 adults living in Portugal between March 19(th) and May 2(nd,) 2020 completed an online survey asking participants about the perceived risk of the COVID-19 and adherence to confinement guidelines. Participants also completed a sociodemographic questionnaire and measures of psychological function. Multiple regression analysis was performed. RESULTS: Teleworking and Risk and COVID-19 controllability were significant predictors of the perceived risk of COVID-19 as measured by the perceived risk of being infected with COVID-19. Teleworking participants and those perceiving COVID-19 as less controllable reported a higher perceived risk of being infected with COVID-19 than those who were not in telework and perceived COVID-19 as a controllable condition. Adherence to confinement guidelines was predicted by the mental health status and perceived risk of COVID-19. Participants who reported worse mental health status, who perceived COVID-19 as a dangerous condition, and who trusted the public health system reported greater adherence to confinement guidelines. CONCLUSIONS: The results of this study will be discussed considering their implications to public health policymaking to promote adherence to public health policies. DISCLOSURE: No significant relationships

Calculation of multiple eigenvalues of the neutron diffusion equation discretized with a parallelized finite volume method

[EN] The spatial distribution of the neutron flux within the core of nuclear reactors is a key factor in nuclear safety. The easiest and fastest way to determine it is by solving the eigenvalue problem of the neutron diffusion equation, which only contains spatial derivatives. The approximation of these derivatives is performed by discretizing the geometry and using numerical methods. In this work, the authors used a finite volume method based on a polynomial expansion of the neutron flux. Once these terms are discretized, a set of matrix equations is obtained, which constitutes the eigenvalue problem. A very effective class of methods for the solution of eigenvalue problems are those based on projection onto a low-dimensional subspace, such as Krylov subspaces. Thus, the SLEPc library was used for solving the eigenvalue problem by means of the Krylov-Schur method, which also uses projection methods of PETSc for solving linear systems. This work includes a complete sensitivity analysis of different issues: mesh, polynomial terms, linear systems solvers and parallelization.This work has been partially supported by the Spanish Ministerio de Eduacion Cultura y Deporte under the grant FPU13/01009, the Spanish Ministerio de Ciencia e Innovacion under the project ENE2014-59442-P, the Spanish Ministerio de Economia y Competitividad and the European Fondo Europeo de Desarrollo Regional (FEDER) under the project ENE2015-68353-P (MINECO/FEDER), the Generalitat Valenciana under the project PROMETEOII/2014/008, and the Spanish Ministerio de Economia y Competitividad and the European Fondo Europeo de Desarrollo Regional (FEDER) under the project TIN2016-075985-P.Bernal-Garcia, A.; Roman, JE.; Miró Herrero, R.; Verdú Martín, GJ. (2018). Calculation of multiple eigenvalues of the neutron diffusion equation discretized with a parallelized finite volume method. Progress in Nuclear Energy. 105:271-278. https://doi.org/10.1016/j.pnucene.2018.02.006S27127810

Multigroup neutron diffusion equation with the finite volume method in reactors using MOX fuels

[EN] The use of mixed oxide (MOX) fuel to partially fill the cores of commercial light water reactors (LWRs) gives rise to a reduction of the radioactive waste and production of more energy. However, the use of MOX fuels in LWRs changes the physics characteristics of the reactor core, since the variation with energy of the cross sections for the plutonium isotopes is more complex than for the uranium isotopes. Although the neutron diffusion theory could be applied to reactors using MOX fuels, more emphasis on treatment of the energy discretization should be placed. This energy discretization could be typically 4¿8 energy groups, instead of the standard 2-energy group approach. In this work, the authors developed a finite volume method for discretizing the general multigroup neutron diffusion equation. This method solves the eigenvalue problem by using Krylov projection methods, in which the size of the vectors used for building the Krylov subspace does not depend on the number of energy groups, but it can solve the multigroup formulation with upscattering and fission production terms in several energy groups. The method was applied to MOX reactors for its validation. © 2017 Atomic Energy Society of Japan. All rights reserved.This work has been partially supported by the Spanish Ministerio de Eduacion Cultura y Deporte [grant number FPU13/01009]; the Spanish Ministerio de Ciencia e Innovacion [project ENE2014-59442-P]; the Spanish Ministerio de Economia y Competitividad and the European Fondo Europeo de Desarrollo Regional (MINECO/FEDER) [project ENE2015-68353-P]; the Generalitat Valenciana [project PROMETEOII/2014/008]; and the Spanish Ministerio de Economia y Competitividad [project TIN2016-75985-P].Bernal-Garcia, A.; Roman, JE.; Miró Herrero, R.; Verdú Martín, GJ. (2017). Multigroup neutron diffusion equation with the finite volume method in reactors using MOX fuels. Journal of Nuclear Science and Technology. 54(11):1251-1260. https://doi.org/10.1080/00223131.2017.1359120S12511260541

State of emergency medicine in Spain

Spain has universal public health care coverage. Emergency care provisions are offered to patients in different modalities and levels according to the characteristics of the medical complaint: at primary care centers (PCC), in an extrahospital setting by emergency medical services (EMS) and at hospital emergency departments (ED). We have more than 3,000 PCCs, which are run by family doctors (general practitioners) and pediatricians. On average, there is 1 PCC for every 15,000 to 20,000 inhabitants, and every family doctor is in charge of 1,500 to 2,000 citizens, although less populated zones tend to have lower ratios. Doctors spend part of their duty time in providing emergency care to their own patients. While not fully devoted to emergency medicine (EM) practice, they do manage minor emergencies. However, Spanish EMSs contribute hugely to guarantee population coverage in all situations. These EMS are run by EM technicians (EMT), nurses and doctors, who usually work exclusively in the emergency arena. EDs dealt with more than 25 million consultations in 2008, which implies, on average, that one out of two Spaniards visited an ED during this time. They are usually equipped with a wide range of diagnostic tools, most including ultrasonography and computerized tomography scans. The academic and training background of doctors working in the ED varies: nearly half lack any structured specialty residence training, but many have done specific master or postgraduate studies within the EM field. The demand for emergency care has grown at an annual rate of over 4% during the last decade. This percentage, which was greater than the 2% population increase during the same period, has outpaced the growth in ED capacity. Therefore, Spanish EDs become overcrowded when the system exerts minimal stress. Despite the high EM caseload and the potential severity of the conditions, training in EM is still unregulated in Spain. However, in April 2009 the Spanish Minister of Health announced the imminent approval of an EM specialty, allowing the first EM resident to officially start in 2011. Spanish emergency physicians look forward to the final approval, which will complete the modernization of emergency health care provision in Spain

Association Between Periodontitis and Blood Pressure Highlighted in Systemically Healthy Individuals: Results From a Nested Case-Control Study

Recent evidence suggests hypertension and periodontitis are closely linked but limited data is available on the nature of the association. We aimed to investigate the relationship between periodontitis and mean arterial blood pressure in a sample of otherwise systemically healthy individuals. A case-control study including 250 cases (participants with periodontitis) and 250 controls (without periodontitis) was designed from a register of clinical trials conducted between 2000 and 2018 in a university setting. Cases were age, sex, and body mass index balanced with controls. Linear, logistic regression, and mediation models were planned to test the association between various periodontal measures and arterial blood pressure. We further investigated the role of systemic inflammation assessed by hs-CRP (high-sensitivity C-reactive protein) and white cell counts. Cases presented with 3.36 mm Hg (95% CI, 0.91-5.82, P=0.007) higher mean systolic blood pressure and 2.16 mm Hg (95% CI, 0.24-4.08, P=0.027) higher diastolic blood pressure than controls. Diagnosis of periodontitis was associated with mean systolic blood pressure (β=3.46±1.25, P=0.005) and greater odds of systolic blood pressure ≥140 mm Hg (odds ratio, 2.3 [95% CI, 1.15-4.60], P=0.018) independent of common cardiovascular risk factors. Similar findings were observed when continuous measures of periodontal status were modeled against systolic blood pressure. Measures of systemic inflammation although elevated in periodontitis were not found to be mediators of the association between periodontitis and arterial blood pressure values. Periodontitis is linked to higher systolic blood pressure in otherwise healthy individuals. Promotion of periodontal and systemic health strategies in the dental and medical setting could help reduce the burden of hypertension and its complications