Optimal streaks in a Falkner-Skan boundary layer

This paper deals with the optimal streaky perturbations (which maximize the perturbed energy growth) in a wedge flow boundary layer. These three dimensional perturbations are governed by a system of linearized boundary layer equations around the Falkner-Skan base flow. Based on an asymptotic analysis of this system near the free stream and the leading edge singularity, we show that for acute wedge semi-angle, all solutions converge after a streamwise transient to a single streamwise-growing solution of the linearized equations, whose initial condition near the leading edge is given by an eigenvalue problem first formulated in this context by Tumin (2001). Such a solution may be regarded as a streamwise evolving most unstable streaky mode, in analogy with the usual eigenmodes in strictly parallel flows, and shows an approximate self-similarity, which was partially known and is completed in this paper. An important consequence of this result is that the optimization procedure based on the adjoint equations heretofore used to define optimal streaks is not necessary. Instead, a simple low-dimensional optimization process is proposed and used to obtain optimal streaks. Comparison with previous results by Tumin and Ashpis (2003) shows an excellent agreement. The unstable streaky mode exhibits transient growth if the wedge semi-angle is smaller than a critical value that is slightly larger than $\pi/6$, and decays otherwise. Thus the cases of right and obtuse wedge semi-angles exhibit less practical interest, but they show a qualitatively different behavior, which is briefly described to complete the analysis

Evolution and study of a copycat effect in intimate partner homicides: A lesson from Spanish femicides

Objectives This paper focuses on the issue of intimate partner violence and, specifically, on the distribution of femicides over time and the existence of copycat effects. This is the subject of an ongoing debate often triggered by the social alarm following multiple intimate partner homicides (IPHs) occurring in a short span of time. The aim of this research is to study the evolution of IPHs and provide a far-reaching answer by rigorously analyzing and searching for patterns in data on femicides. Methods The study analyzes an official dataset, provided by the system VioGén of the Secretaría de Estado de Seguridad (Spanish State Secretariat for Security), including all the femicides occurred in Spain in 2007-2017. A statistical methodology to identify temporal interdepen-dencies in count time series is proposed and applied to the dataset. The same methodology can be applied to other contexts. Results There has been a decreasing trend in the number of femicides per year. No interdependen-cies among the temporal distribution of femicides are observed. Therefore, according to data, the existence of copycat effect in femicides cannot be claimed. Conclusions Around 2011 there was a clear change in the average number of femicides which has not picked up. Results allow for an informed answer to the debate on copycat effect in Spanish femicides. The planning of femicides prevention activities should not be a reaction to a perceived increase in their occurrence. As a copycat effect is not detected in the studied time period, there is no evidence supporting the need to censor media reports on femicides.The work by Torrecilla has been partially supported by Spanish Grant MTM2016-78751-P. The research of Liberatore has been supported by the Government of Spain, grant MTM2015-65803-R, and by the Government of Madrid, grant S2013/ICE-284

The direct boundary element method: 2D site effects assessment on laterally varying layered media (methodology)

The Direct Boundary Element Method (DBEM) is presented to solve the elastodynamic field equations in 2D, and a complete comprehensive implementation is given. The DBEM is a useful approach to obtain reliable numerical estimates of site effects on seismic ground motion due to irregular geological configurations, both of layering and topography. The method is based on the discretization of the classical Somigliana's elastodynamic representation equation which stems from the reciprocity theorem. This equation is given in terms of the Green's function which is the full-space harmonic steady-state fundamental solution. The formulation permits the treatment of viscoelastic media, therefore site models with intrinsic attenuation can be examined. By means of this approach, the calculation of 2D scattering of seismic waves, due to the incidence of P and SV waves on irregular topographical profiles is performed. Sites such as, canyons, mountains and valleys in irregular multilayered media are computed to test the technique. The obtained transfer functions show excellent agreement with already published results

Magneto-caloric effect in the pseudo-binary intermetallic YPrFe17 compound

We have synthesized the intermetallic YPrFe17 compound by arc-melting. X-ray and neutron powder diffraction show that the crystal structure is rhombohedral with View the MathML source space group (Th2Zn17-type). The investigated compound exhibits a broad isothermal magnetic entropy change {\Delta}SM(T) associated with the ferro-to-paramagnetic phase transition (TC \approx 290 K). The |{\Delta}SM| (\approx 2.3 J kg-1 K-1) and the relative cooling power (\approx 100 J kg-1) have been calculated for applied magnetic field changes up to 1.5 T. A single master curve for {\Delta}SM under different values of the magnetic field change can be obtained by a rescaling of the temperature axis. The results are compared and discussed in terms of the magneto-caloric effect in the isostructural R2Fe17 (R = Y, Pr and Nd) binary intermetallic alloys.Comment: Preprint, 5 pages (postprint), 4 figures, regular pape

La influencia de los principales modos de variabilidad interanual en la demanda energética domestica

Ponencia presentada en: VII Congreso de la Asociación Española de Climatología: clima, ciudad y ecosistemas, celebrado en Madrid entre el 24 y 26 de noviembre de 2010.[ES]En este trabajo caracterizamos la demanda energética doméstica en término de grados-día de calentamiento y enfriamiento. Los principales modos climáticos que influyen en la variabilidad interanual en la Península Ibérica son El Nino-La Oscilación del Sur y la Oscilación del Atlántico Norte. Determinamos aquí si existe una influencia significativa de estos modos sobre los índices mensuales de calentamiento o enfriamiento que sirven para calcular los grados-días. Para estimar estos índices se utilizan observaciones meteorológicas diarias en 32 observatorios de la Península Ibérica en el periodo 1958-2005. Aplicamos una prueba estadística de rango para determinar si existe una dependencia significativa en la fase de la NAO, en la fase de ENSO, y si hay interacción en la influencia de estos dos modos.[EN]In the present study we characterize the domestic energy demand in terms of heating and cooling degree-days. The principal climate modes that influence the interannual variability of the Iberian Peninsula are the El Nino-the Southern Oscillation and the North Atlantic Oscillation. We determine here the influence that those modes have on the mensual heating and cooling climate indices used in the computation of the degree-days. Those indices are estimated from daily temperature data at 32 meteorological stations at the Iberian Peninsula, for the period 1958-2005. We use a rank statistical test to determine if there is a significant influence of the NAO phase, or of the ENSO phase on those indices. We also test if there is some interaction between the influence of the climate modes.Este estudio está financiado parcialmente por el proyecto CIRCE (CGL-036961) de la Unión Europea

Influencia de los principales modos de variabilidad interanual en la demanda energética doméstica [Póster]

Póster presentado en: VII Congreso de la Asociación Española de Climatología: clima, ciudad y ecosistemas, celebrado en Madrid entre el 24 y 26 de noviembre de 2010.Este estudio ha sido financiado parcialmente por el proyecto CIRCE (CGL-­‐036961) de la U.E

Anthropometric Profile Assessed by Bioimpedance and Anthropometry Measures of Male and Female Rugby Players Competing in the Spanish National League

Different rugby positions make different demands on players. It therefore follows that optimum body composition may vary according to the position played. Using anthropometry and bioimpedance analysis (BIA) to assess body composition, the present study aimed to compare the effect of sex and position on body composition variables using anthropometry and BIA methods. A total of 100 competitive rugby players (35 women and 65 men) competing in the First Spanish National League were recruited voluntarily and for convenience for this study. In the laboratory, body composition was assessed by anthropometry, following the recommendations established by the International Society for the Advancement of Kinanthropometry (ISAK), and by direct segmental multi-frequency BIA, following the guidelines established by the Spanish Group of Kinanthropometry (GREC) of the Spanish Federation of Sports Medicine (FEMEDE). We found sex-related differences in height, weight, body mass index and body fat (%) by anthropometry and in body lean mass (%) by DSM-BIA, in 4 of the 6 skinfolds assessed (p < 0.05). We also observed position-related differences in all the variables assessed (p < 0.05) except for lean body mass, as measured by both methods of determining body composition, and front thigh skinfold. Body composition and ∑6skinfolds differs according to sex and playing position, backs (16.6 ± 3.8% and 92.3 ± 33.9 mm,) vs. forwards (20.0 ± 6.7 and 115.3 ± 37.6 mm), and the muscle-adipose (meso-endomorphic somatotype) development predominated in both sexes. Thus, forwards of both sexes are taller, heavier and fatter, possibly due to the specific demands of this position. In addition, body composition measurements vary according to the method used (DSM-BIA vs. anthropometry), indicating that anthropometry is probably the best body composition assessment method

Operational realization of quantum vacuum ambiguities

We provide a reinterpretation of the quantum vacuum ambiguities that one encounters when studying particle creation phenomena due to an external and time-dependent agent. We propose a measurement-motivated understanding: Each way of measuring the number of created particles selects a particular vacuum. This point of view gives a clear and physical meaning to the time evolution of the number of particles produced by the agent as the counts in a specific detector and, at the same time relates commonly used quantization prescriptions to particular measurement setups.Comment: 6 pages, 3 figure

Interaction of 8 He with 208Pb at near-barrier energies: 4 He and 6 He production

Spanish Ministry of Economy and Competitiveness-FPA-2010-22131-CO2-01 (FINURA) y FPA2013-47327-C2-1-RMinistry of Science and Higher Education of Poland-N202 033637National Science Centre of Poland-2013/08/M/ST2/00257 (LEA-COPIGAL) y 2014/14/M/ST2/00738 (COPIN-INFN Collaboration)European Science Foundation-EUI2009-04163432 (EUROGENESIS

Interactive effects of solar radiation and inorganic nitrogen on biofiltration, biomass production, photosynthetic activity and the accumulation of bioactive compounds i

Interactive effects of solar radiation and inorganic nitrogen and phosphate on biofiltration capacity, biomass production, photosynthetic activity and the accumulation of bio-active compounds were studied in the red alga Gracilaria cornea grown in tanks with a seawater open-flow system during 35 days. Two light conditions were utilized: outdoor (O), full solar natural radiation, and indoor, inside of a greenhouse (G) where UV-B radiation was cut-off and part of the UV-A radiation was filtered. Two inorganic nitrogen and phosphate concentrations were used: High nutrients (HN; 100–200μM of NH4+ and 20μM of KHPO4) and Low nutrients (LN; 10–20μM of NH4+ and 1μM of KHPO4). Growth and biomass productivity were related to the daily integrated electron transport rate determined in situ, as an estimator of daily photosynthetic activity. Nitrogen uptake efficiency (NUE) was close to 100 % under LN, whereas under HN it ranged from 50 to 70 % in the first week of culture, decreasing to 10–15 % in the rest of the experimental period. Nitrogen uptake rate (NUR) ranged from 20 to 45 mmol N m−2 h−1 under HN, and 5 to 18 mmol N m−2 h−1 in LN treatments. Morphological and pigmentation changes were evident through the culture period. The thalli under HN were more reddish under the indoor treatments, than that in LN. The internal compounds increased throughout the experimental period. Mycosporine-like amino acids (MAAs) were accumulated under HN. N plays a photoprotective role due to both the increased photosynthesis and the MAA content. Maximal MAA productivity reached 113–253 mg MAAs m−2 d−1 under the O-HN treatment, the highest level reported until now in the bibliography. G. cornea could be used for bioremediation of high N content waters. In addition, under full solar radiation and high N availability produce high levels of bioactive compounds as MAAs, polyphenols and biliproteins for cosmeceutical applications.This study was financed by resources of the Photobiology and Biotechnology of aquatic organisms (FYBOA-RNM 295) research group and the Project “Photoprotectors of marine algae: compatible cosmeceutics to the ocean” (UMA18-FEDER JA-162) and Nazca Project (P20-00458) of the Andalusian Goverment. Funding for open access charge: Universidad de Málaga / CBUA