Excitations in one-dimensional lattices with traps: exact results and simulations

We study motion and capture of incoherent excitons in one-dimensional lattices with randomly placed, perfectly absorbing traps. Large-scale numerical simulations of both the master equation and the random walk version of the problem disagree with the result for the survival fraction obtained long ago by Movaghar et al. [J. Stat. Phys. 27 (1982) 473]. We carry out exact calculations for this problem and find that the disagreement can be traced back to rare-event contributions to the analytical result which cannot be seen in simulations. We conclude that for practical purposes, Le., for averages taken over any finite number of realizations, the only asymptotics observable is the one we have found in our simulations.Work at Madrid and Leganes is supported by CICYT under project MAT95-0325. Work at Cantabria is supported by OGICYT under project PB93-0054-C02-02.Publicad

Learning from failure propagation in steel truss bridges

Although truss-type bridge collapses usually have catastrophic consequences, their analysis present opportunities for improving different aspects in the field of bridge engineering, such as structural assessment, structural health monitoring, maintenance and conservation or even design strategies. As the world experiences more extreme events, efforts have been made to design more resilient bridges that can withstand local failures. Forensic techniques have contributed to understanding the causes and risk factors of bridge failures, and the creation of collapse databases has provided valuable insights for preventing such failures. However, these databases often focus on the hazards and do not provide information on initial damage and how it propagates, which is essential for improving the progressive collapse resistance of truss-type bridges. The main novelty of this paper is to present a methodology to identify triggering events leading to progressive collapse on truss-type bridges. It is the first time that a methodology includes a novel database which collects detailed information on initial damages and its propagation, as well as the consequences of the collapse. The methodology was implemented by collecting information from 25 case studies present in the literature. Results have allowed to identify most frequent initial constituted damages states or failures (ICDS) leading progressive collapse. In terms of consequences, results were thoroughly analysed and compared with predictions from different casualty models. The findings showed that the proposed methodology serves as an effective tool for identifying the triggering events of progressive collapse in truss-type bridges.Agencia Estatal de Investigación | Ref. PID2021-124236OBAgencia Estatal de Investigación | Ref. FJC2020–046370-IUniversidade de Vigo/CISU

Initiation and propagation of failures in steel truss bridges

Bridge collapses are catastrophic events with countless consequences. However, bridge engineering has progressed thanks to the knowledge acquired analyzing collapsed structures. In this direction, modern forensic techniques allow detecting weaknesses and vulnerable zones in the structural systems. It has been demonstrated that the data related to bridge failures has been fundamental for engineers to propose and update theories, concepts, and designs in bridge engineering. This paper presents a methodology to analyze the initial damage and its propagation on steel truss bridges. The first part of the paper presents a comprehensive review of state‐of‐the‐art and scientific challenges. The methodology is described in detail in the second part of the paper; it comprises two main tasks that are further divided into several activities. This methodology was developed as part of the “Pont3” project and has proven to be of great value in gaining a better understanding of how progressive collapse occurs in steel truss bridges. By using this methodology, it is possible to detect initial damage and evaluate the structural behavior of steel truss bridges, which will ultimately lead to safer and more reliable structures.Universidade de Vigo/CISU

Assessment of hormonal parameters in long-term karate Practitioners

Introduction: Karate is a Japanese martial art which is widely practiced in the Western world as a form of self-defense, as well as a discipline to achieve physical and mental balance.However, little is known with respect to its specific psychobiological effects, particularly in relation to the influence that karate may exert on the endocrine system. Thus, in the present study we analyzed the effects of regular karate practice on several hormonal parameters. Methods: 27 healthy volunteer subjects participated in the study, of whom 15 were allocated to the experimental group, and 12 were assigned to the control group. Experimental subjects were karate players with a minimum of 3 years of practice in this discipline. Blood samples for the quantification of hormonal parameters (TSH, T3, T4, PTH, ACTH, cortisol, and DHEA) were taken in both groups. To compare the means of the control and experimental group, a t-test for independent groups was performed in each dependent variable. Results: Significant differences between the experimental and control group were found in T3, T4, and cortisol, with karate players showing lower blood levels of these hormones than control. Conclusions: These findings reveal that long-term karate practice is associated to a significant endocrine modulation, which suggests interesting psychobiological implications, and lends itself to potential clinical considerations. Further research is needed to properly assess the scope of the peculiar hormonal profile displayed by advanced karate practitioners.Universidad de Málaga, Campus de Excelencia Internacional Andalucía Tec

Immune modulation after long-term karate practice

Introduction: Karate is a Japanese martial arts system which traces its roots back to China, and is nowadays widely popular both as a method of self-defense, as well as a discipline with potential physical and psychological benefits. However, karate has been scarcely investigated from a psychobiological perspective, and its effects on the immune system remain virtually unknown. Therefore, we designed the present study with the aim of analyzing the effects of several years of regular karate practice on different immune parameters. Methods: 27 healthy volunteer subjects participated in the study, 15 being allocated to the experimental group, and 12 to the control group. Experimental subjects were all karate players who had practiced this martial art for a minimum of three years. Blood samples for the quantification of immune parameters (leukocytes, neutrophils, monocytes, eosinophils, basophils, lymphocytes, IgG, IgA, IgM, IgE) were taken in both groups. As statistical analysis, a t-test for independent groups was performed in each dependent variable. Results: Compared to the control group, karate practitioners exhibited a significantly higher number of leukocytes, monocytes, and lymphocytes, as well as greater serum concentrations of IgG and IgM. Conclusions: Our findings show that long-term karate practice is related to a broad modulation of immune parameters, including leukocytes counts as well as immunoglobulin concentrations. This peculiar immunomodulatory profile, apart from its psychobiological relevance, may have noteworthy clinical implications. Further investigation would be necessary to fully elucidate the influence that long-term karate training can exert on the immune system.Universidad de Málaga, Campus de Excelencia Internacional Andalucía Tec

Inyecciones de conglomerados en el Triásico de Pálmaces de Jadraque (Guadalajara)

Conglomerate dykes have been observed in Buntsandstenin deposits surrounding of Palmaces de Jadraque dam (Spanish Central System southeast border). Deformed sediments by liquefaction correspond to fluvial systems of mixed load rivers of gravels and sands. Conglomerate dykes have a true tectonic control. These structures have a mean trend NW-SE and another perpendicular one, are less developed. These trends are compatible with extensional process proposed by different authors for this time. Due to tectonic control as well as the associated tectonic extensional process, liquefactions trigger mechanism could be seismic

Texture-induced enhancement of the magnetocaloric response in melt-spun DyNi2 ribbons

"The magnetocaloric properties of melt-spun ribbons of the Laves phase DyNi2 have been investigated. The as-quenched ribbons crystallize in a single-phase MgCu2-type crystal structure (C15; space group Fd (3) over barm) exhibiting a saturation magnetization and Curie temperature of M-S = 157 +/- 2 A m(2) kg(-1) and T-C = 21.5 +/- 1 K, respectively. For a magnetic field change of 2 T, ribbons show a maximum value of the isothermal magnetic entropy change vertical bar Delta S-M(peak)vertical bar = 13.5 J kg(-1) K-1, and a refrigerant capacity RC = 209 J kg(-1). Both values are superior to those found for bulk polycrystalline DyNi2 alloys (25% and 49%, respectively). In particular, the RC is comparable or larger than that reported for other potential magnetic refrigerants operating at low temperatures, making DyNi2 ribbons promising materials for use in low-temperature magnetic refrigeration applications.

Texture-induced enhancement of the magnetocaloric response in melt-spun DyNi2 ribbons

"The magnetocaloric properties of melt-spun ribbons of the Laves phase DyNi2 have been investigated. The as-quenched ribbons crystallize in a single-phase MgCu2-type crystal structure (C15; space group Fd (3) over barm) exhibiting a saturation magnetization and Curie temperature of M-S = 157 +/- 2 A m(2) kg(-1) and T-C = 21.5 +/- 1 K, respectively. For a magnetic field change of 2 T, ribbons show a maximum value of the isothermal magnetic entropy change vertical bar Delta S-M(peak)vertical bar = 13.5 J kg(-1) K-1, and a refrigerant capacity RC = 209 J kg(-1). Both values are superior to those found for bulk polycrystalline DyNi2 alloys (25% and 49%, respectively). In particular, the RC is comparable or larger than that reported for other potential magnetic refrigerants operating at low temperatures, making DyNi2 ribbons promising materials for use in low-temperature magnetic refrigeration applications.

Effect of acid mine drainage on the mechanical properties of AISI 1020 carbon steel and AW6060 aluminium

Acid mine drainage severely affects metallic materials due to the high acidity and oxidising capacity of these lixiviates. A study was carried out to evaluate the time evolution of the mechanical properties of AISI 1020 carbon steel and AW6060 aluminium in contact with acid mine drainage. Weight loss, fatigue and tensile strength were evaluated in two different scenarios, one involving erosion corrosion (dynamic scenario) and the other involving chemical corrosion only (static scenario). Over 80 days of exposure in a static scenario, weight loss is almost 2% for aluminium and 0.5% for steel, fatigue strength is reduced by 28% for steel and ultimate tensile strength is reduced by almost 5% for aluminium and by 2.5% for steel. In a dynamic scenario, the weight loss after 4 days of exposure is 30–35% for both materials, the fatigue strength is reduced by almost 50% for steel, the ultimate tensile strength is reduced by 33% for aluminium and by almost 5% for steel. Acid drainage causes an increase in brittleness and a decrease in stiffness of these materials, much more rapidly in a dynamic environment favoured by the effects of erosion corrosion.CIN/AEI/10.13039/501100011033/FEDER, UE, throughout the project PID2021-123130OB-I00

Hallazgos electroclínicos y evolutivos en pacientes con alteración en el gen KCNQ2. Serie de 6 casos

Introducción: Los trastornos relacionados con las alteraciones en el gen KCNQ2 incluyen un amplio rango de fenotipos epilépticos de inicio en la edad neonatal, desde epilepsia neonatal familiar benigna (ENFB) hasta casos de encefalopatía epiléptica neonatal (EEN) que en algunas ocasiones presentan características similares al síndrome de Ohtahara con un trazado de tipo paroxismo-supresión aunque con mejor control de crisis e infrecuente evolución a síndrome de West. Pacientes y métodos: Estudio descriptivo y retrospectivo de una serie de 6 casos con crisis de inicio en la etapa neonatal y presencia de mutación en el gen KCNQ2. Resultados: las crisis se iniciaron en todos los casos en la primera semana de vida, siendo las más frecuentes las crisis tónicas, seguidas de las crisis sutiles y las crisis hemiclónicas. Un paciente asoció además mioclonias y trastornos del movimiento. En el EEG del período neonatal destaca la presencia de actividad paroxística focal en 4 pacientes y trazado de brote-supresión en 2 casos. En las pruebas de neuroimagen, en 5 de los pacientes, se encontraron anomalías de diverso tipo (atrofia cortical, asimetría en astas temporales, alteración de la sustancia blanca periventricular y polimicrogiria). En la evolución posterior, 5 casos presentaron retraso psicomotor en mayor o menor grado, de los cuales, 3 desarrollaron epilepsia focal sintomática, un caso Síndrome de West y otro, encefalopatía epiléptica. Por último, un paciente fue diagnosticado de ENFB con buena evolución clínica y electroencefalográfica. Conclusión: Existe un amplio espectro en el tipo de epilepsia asociada a las alteraciones del gen KCNQ2 con características electroclínicas y evolutivas muy diversas, destacando en nuestra serie los casos con epilepsia focal sintomática y encefalopatía epiléptica (uno de ellos con S. West). Sólo un paciente tuvo una forma benigna de epilepsia (ENFB).Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech