A visualization of the damage in Lead Tungstate calorimeter crystals after exposure to high-energy hadrons

The anticipated performance of calorimeter crystals in the environment expected after the planned High-Luminosity upgrade of the Large Hadron Collider (HL-LHC) at CERN has to be well understood, before informed decisions can be made on the need for detector upgrades. Throughout the years of running at the HL-LHC, the detectors will be exposed to considerable fluences of fast hadrons, that have been shown to cause cumulative transparency losses in Lead Tungstate scintillating crystals. In this study, we present direct evidence of the main underlying damage mechanism. Results are shown from a test that yields a direct insight into the nature of the hadron-specific damage in Lead Tungstate calorimeter crystals exposed to 24 GeV/c protons.Comment: 8 pages, 6 figure

Characterization of single-molecule pentanedithiol junctions by inelastic electron tunneling spectroscopy and first-principles calculations

We study pentanedithiol molecular junctions formed by means of the break-junction technique with a scanning tunneling microscope at low temperatures. Using inelastic electron tunneling spectroscopy and first-principles calculations, the response of the junction to elastic deformation is examined. We show that this procedure makes a detailed characterization of the molecular junction possible. In particular, our results indicate that tunneling takes place through just a single molecule.Comment: 5 pages, 4 figures (accepted in Phys. Rev. B

Scaling Beyond Cities

City population size is a crucial measure when trying to understand urban life. Many socio-economic indicators scale superlinearly with city size, whilst some infrastructure indicators scale sublinearly with city size. However, the impact of size also extends beyond the city’s limits. Here, we analyse the scaling behaviour of cities beyond their boundaries by considering the emergence and growth of nearby cities. Based on an urban network from African continental cities, we construct an algorithm to create the region of influence of cities. The number of cities and the population within a region of influence are then analysed in the context of urban scaling. Our results are compared against a random permutation of the network, showing that the observed scaling power of cities to enhance the emergence and growth of cities is not the result of randomness. By altering the radius of influence of cities, we observe three regimes. Large cities tend to be surrounded by many small towns for small distances. For medium distances (above 114 km), large cities are surrounded by many other cities containing large populations. Large cities boost urban emergence and growth (even more than 190 km away), but their scaling power decays with distance

Inferring urban polycentricity from the variability in human mobility patterns

The polycentric city model has gained popularity in spatial planning policy, since it is believed to overcome some of the problems often present in monocentric metropolises, ranging from congestion to difficult accessibility to jobs and services. However, the concept 'polycentric city' has a fuzzy definition and as a result, the extent to which a city is polycentric cannot be easily determined. Here, we leverage the fine spatio-temporal resolution of smart travel card data to infer urban polycentricity by examining how a city departs from a well-defined monocentric model. In particular, we analyse the human movements that arise as a result of sophisticated forms of urban structure by introducing a novel probabilistic approach which captures the complexity of these human movements. We focus on London (UK) and Seoul (South Korea) as our two case studies, and we specifically find evidence that London displays a higher degree of monocentricity than Seoul, suggesting that Seoul is likely to be more polycentric than London

Role of elastic scattering in electron dynamics at ordered alkali overlayers on Cu(111)

Scanning tunneling spectroscopy of p(2x2) Cs and Na ordered overlayers on Cu(111) reveals similar line widths of quasi two-dimensional quantum well states despite largely different binding energies. Detailed calculations show that 50% of the line widths are due to electron-phonon scattering while inelastic electron-electron scattering is negligible. A frequently ignored mechanism for ordered structures, i.e., enhanced elastic scattering due to Brillouin zone back folding, contributes the remaining width.Comment: 4 pages, 2 figures, 1 tabl

La fijación externa en el tratamiento de las fracturas de extremidad distal de radio: Revisión de 83 casos

Se presenta un estudio retrospectivo de 83 casos de fractura de extremidad distal de radio tratadas con fijación externa, exclusivamente o asociada a otros métodos de tratamiento, con un seguimiento medio de 15 meses. Se han revisado las indicaciones y se han valorado los resultados mediante el protocolo de evaluación clínica propuesto por Gartland y Werley, modificado por Sarmiento; y la evaluación radiológica según los criterios de Linström, ampliados por Van Der Linden y Ericsson. Se obtuvieron resultados excelentes en 9 casos, buenos en 44 casos, regulares en 24 y malos en 6 casos. La complicación más frecuente hallada fue la osteopenia difusa del carpo (50%) y la causa más común de discapacidad residual, la articulación radiocubital distal. De los resultados concluimos que la fijación externa es un método correcto para el tratamiento de las fracturas de extremidad distal de radio, aunque son necesarias en algunos casos otras técnicas añadidas para conseguir una aceptable congruencia articular y minimizar la cifra de resultados inaceptables.Retrospective study on 83 cases of distal radius fractures in treatment with external fixation, exclusively or associated with other treatment methods, with an average follow-up of 45 months. Indications have been revised and results have been valued through the medical record of clinical evaluation proposed by Gartland and Werley, modified by Sarmiento, and the radiological evaluation accordinf to Linström's criterions, amplified by Van Der Linden and Ericson. Excellent results have been obtained in 9 cases, good ones in 44 cases, not bad ones in 24 cases, bad ones in 6 cases. The most frequent complication found was the carpus wide osteopeny (50%) and the most common cause of residual discapacity, the distal radioulnar joint. We conclude, from the results, that the external fixation is a correct method for the treatment of distal radius fractures, although other added techniques are necessary, in some cases, in order to achieve an acceptable articular congruity and minimize the number of unacceptable results

Numerical Study of Wave Forces on Crown Walls of Mound Breakwaters with Parapets

[EN] The influence of parapets on crown walls of mound breakwaters on wave forces has not been extensively analyzed in the literature. In this study, numerical experiments were carried out using the open-source platform OpenFOAM(R) to evaluate the influence of nine crown wall geometries with and without parapets. The OpenFOAM(R) model was validated with laboratory experiments. Dimensionless horizontal forces and overturning moments due to horizontal forces increase when there is a parapet. Dimensionless up-lift forces provide similar results, regardless of the existence of a parapet. Crown walls with parapets increase the horizontal wave forces and overturning moments due to horizontal wave forces by a factor of two.This research was funded by (1) Universitat Politecnica de Valencia (Grant SP20180111, Primeros Proyectos de Investigacion (PAID-06-18), Vicerrectorado de Investigacion, Innovacion y Transferencia de la Universitat Politecnica de Valencia) and (2) Spanish Ministerio de Ciencia, Innovacion y Universidades (Grant RTI2018-101073-B-I00).Molines, J.; Bayón, A.; Gómez-Martín, ME.; Medina, JR. (2020). Numerical Study of Wave Forces on Crown Walls of Mound Breakwaters with Parapets. Journal of Marine Science and Engineering. 8(4):1-15. https://doi.org/10.3390/jmse8040276S11584Molines, J., Bayon, A., Gómez-Martín, M. E., & Medina, J. R. (2019). Influence of Parapets on Wave Overtopping on Mound Breakwaters with Crown Walls. Sustainability, 11(24), 7109. doi:10.3390/su11247109Martinelli, L., Ruol, P., Volpato, M., Favaretto, C., Castellino, M., De Girolamo, P., … Sammarco, P. (2018). Experimental investigation on non-breaking wave forces and overtopping at the recurved parapets of vertical breakwaters. Coastal Engineering, 141, 52-67. doi:10.1016/j.coastaleng.2018.08.017Nørgaard, J. Q. H., Andersen, T. L., & Burcharth, H. F. (2013). Wave loads on rubble mound breakwater crown walls in deep and shallow water wave conditions. Coastal Engineering, 80, 137-147. doi:10.1016/j.coastaleng.2013.06.003Molines, J., Herrera, M. P., & Medina, J. R. (2018). Estimations of wave forces on crown walls based on wave overtopping rates. Coastal Engineering, 132, 50-62. doi:10.1016/j.coastaleng.2017.11.004Van Gent, M. R. A., & van der Werf, I. M. (2019). Influence of oblique wave attack on wave overtopping and forces on rubble mound breakwater crest walls. Coastal Engineering, 151, 78-96. doi:10.1016/j.coastaleng.2019.04.001Castellino, M., Sammarco, P., Romano, A., Martinelli, L., Ruol, P., Franco, L., & De Girolamo, P. (2018). Large impulsive forces on recurved parapets under non-breaking waves. A numerical study. Coastal Engineering, 136, 1-15. doi:10.1016/j.coastaleng.2018.01.012Issa, R. . (1986). Solution of the implicitly discretised fluid flow equations by operator-splitting. Journal of Computational Physics, 62(1), 40-65. doi:10.1016/0021-9991(86)90099-9Patankar, S. ., & Spalding, D. . (1972). A calculation procedure for heat, mass and momentum transfer in three-dimensional parabolic flows. International Journal of Heat and Mass Transfer, 15(10), 1787-1806. doi:10.1016/0017-9310(72)90054-3Jacobsen, N. G., van Gent, M. R. A., Capel, A., & Borsboom, M. (2018). Numerical prediction of integrated wave loads on crest walls on top of rubble mound structures. Coastal Engineering, 142, 110-124. doi:10.1016/j.coastaleng.2018.10.004Jensen, B., Jacobsen, N. G., & Christensen, E. D. (2014). Investigations on the porous media equations and resistance coefficients for coastal structures. Coastal Engineering, 84, 56-72. doi:10.1016/j.coastaleng.2013.11.004Hirt, C. ., & Nichols, B. . (1981). Volume of fluid (VOF) method for the dynamics of free boundaries. Journal of Computational Physics, 39(1), 201-225. doi:10.1016/0021-9991(81)90145-5Berberović, E., van Hinsberg, N. P., Jakirlić, S., Roisman, I. V., & Tropea, C. (2009). Drop impact onto a liquid layer of finite thickness: Dynamics of the cavity evolution. Physical Review E, 79(3). doi:10.1103/physreve.79.036306Jacobsen, N. G., van Gent, M. R. A., & Wolters, G. (2015). Numerical analysis of the interaction of irregular waves with two dimensional permeable coastal structures. Coastal Engineering, 102, 13-29. doi:10.1016/j.coastaleng.2015.05.004Higuera, P., Lara, J. L., & Losada, I. J. (2014). Three-dimensional interaction of waves and porous coastal structures using OpenFOAM®. Part II: Application. Coastal Engineering, 83, 259-270. doi:10.1016/j.coastaleng.2013.09.002Higuera, P., Lara, J. L., & Losada, I. J. (2013). Realistic wave generation and active wave absorption for Navier–Stokes models. Coastal Engineering, 71, 102-118. doi:10.1016/j.coastaleng.2012.07.002Higuera, P., Lara, J. L., & Losada, I. J. (2013). Simulating coastal engineering processes with OpenFOAM®. Coastal Engineering, 71, 119-134. doi:10.1016/j.coastaleng.2012.06.002Higuera, P., Lara, J. L., & Losada, I. J. (2014). Three-dimensional interaction of waves and porous coastal structures using OpenFOAM®. Part I: Formulation and validation. Coastal Engineering, 83, 243-258. doi:10.1016/j.coastaleng.2013.08.010Bayon-Barrachina, A., & Lopez-Jimenez, P. A. (2015). Numerical analysis of hydraulic jumps using OpenFOAM. Journal of Hydroinformatics, 17(4), 662-678. doi:10.2166/hydro.2015.041Bayon, A., Valero, D., García-Bartual, R., Vallés-Morán, F. ​José, & López-Jiménez, P. A. (2016). Performance assessment of OpenFOAM and FLOW-3D in the numerical modeling of a low Reynolds number hydraulic jump. Environmental Modelling & Software, 80, 322-335. doi:10.1016/j.envsoft.2016.02.018Bayon, A., Toro, J. P., Bombardelli, F. A., Matos, J., & López-Jiménez, P. A. (2018). Influence of VOF technique, turbulence model and discretization scheme on the numerical simulation of the non-aerated, skimming flow in stepped spillways. Journal of Hydro-environment Research, 19, 137-149. doi:10.1016/j.jher.2017.10.002Romano, A., Bellotti, G., Briganti, R., & Franco, L. (2015). Uncertainties in the physical modelling of the wave overtopping over a rubble mound breakwater: The role of the seeding number and of the test duration. Coastal Engineering, 103, 15-21. doi:10.1016/j.coastaleng.2015.05.00

Interactions of Ar(9+) and metastable Ar(8+) with a Si(100) surface at velocities near the image acceleration limit

Auger LMM spectra and preliminary model simulations of Ar(9+) and metastable Ar(8+) ions interacting with a clean monocrystalline n-doped Si(100) surface are presented. By varying the experimental parameters, several yet undiscovered spectroscopic features have been observed providing valuable hints for the development of an adequate interaction model. On our apparatus the ion beam energy can be lowered to almost mere image charge attraction. High data acquisition rates could still be maintained yielding an unprecedented statistical quality of the Auger spectra.Comment: 34 pages, 11 figures, http://pikp28.uni-muenster.de/~ducree

APPLICATION OF BIOMECHANICS TO THE PREVENTION OF OVERLOAD INJURIES IN ELITE SOCCER PLAYERS.

Structural alterations of the foot and inadequate design of sports footwear, as well as overtraining, have been determined to be risk factors for overload injuries during sports practice. A biomechanical analysis protocol was designed to study both, the foot and sports footwear statically and dynamically. This protocol was applied on 47 soccer players of the Spanish Premier League. Amongst the results we should point out that 53.3% of the players had cavus feet. 14.8% of the players deformed the boots. 44.7% of the players studied registered high pressures over the metatarsal heads. and 19.1 % registered high ones at the first toe. 44.7% of the players showed an excessive supination pattern. The data obtained gave us information about the static and dynamic patterns of the elite soccer player. With the individual information the assessment of suitable footwear was carried out for each player. The correct application of this protocol could be used in the diagnosis or prevention of overtraining and in the detection of foot and gait pathologies