Comedia heroica : El Rey D. Sebastian y portugues mas heroico : en tres actos

Precede al tít. ¨Comedia heroica. N. 10

Origen y definición de la necedad, con anotaciones a algunas necedades de las que se usan.

“A menudo se reniega de los maestros supremos; se rebela uno contra ellos; se enumeran sus defectos; se los acusa de ser aburridos, de una obra demasiado extensa, de extravagancia, de mal gusto, al tiempo que se los saquea, engalanándose con plumas ajenas; pero en vano nos debatimos bajo su yugo. Todo se tiñe de sus colores; por doquier encontramos sus huellas; inventan palabras y nombres que van a enriquecer el vocabulario general de los pueblos; sus expresiones se convierten en proverbiales, sus personajes ficticios se truecan en personajes reales, que tienen herederos y linaje. Abren horizontes de donde brotan haces de luz; siembran ideas, gérmenes de otras mil; proporcionan motivos de inspiración, temas, estilos a todas las artes: sus obras son las minas o las entrañas del espíritu humano” (François de Chateaubriand: Memorias de ultratumba, libro XII, capítulo I, 1822).&nbsp

Determination of strength and debonding energy of a glass-concrete interface for encapsulation-based self-healing concrete

This paper presents a combined experimental-numerical analysis to assess the strength and fracture toughness of a glass-concrete interface. This interface is present in encapsulation-based self-healing concrete. There is absence of published results of these two properties, despite their important role in the correct working of this self-healing strategy. Two setups are used: uniaxial tensile tests to assess the bonding strength and four point bending tests to get the interfacial energy. The complementary numerical models for each setup are conducted using the finite element method. Two approaches are used: cohesive zone model to study the interface strength and the virtual crack closure technique to analyze the interfacial toughness. The models are validated and used to verify the experimental interpretations. It is found that a glass-concrete interface can develop a maximum strength of approximately 1 N/mm^2 with fracture energy of 0.011 J/m^2

Concrete fracture energy increase by embedding capsules with healing ability : the effect of capsules nature

Concrete is the basic material of infrastructures since it is cost-effective, efficiently produced and strong. Despite its popularity, under service-loads the concrete matrix suffers from flaws that can be crucial for its durability. To overcome the shortcoming in durability, concrete is traditionally reinforced by steel or its mixture is modified by introducing additives that enrich the autogenous crack closure. Nowadays, an alternative solution is proposed namely autonomous healing. Repair polymer agent is encapsulated into tubes and embedded into concrete during mixture. The tubes break as soon as a crack wider than 100 μm is propagated across them. Only at this moment, the agent is released and polymerized. The crack void is sealed and repaired (mechanical features restored as well). The previous years, researchers at the Dept. Mechanics of Materials and Constructions, VUB have studied the mechanical performance of newly developed healing systems and evaluated their repair efficiency. In this study, an additional benefit of autonomous healing is assessed: the short or long tubes contribute as local reinforcement of concrete under tensile load and enhance the fracture toughness. The energy release rate and other fracture mechanics parameters are measured for plain concrete beams tested under three-point bending. The reference case (concrete carrying no healing system) is compared to cases at which different encapsulation systems are applied. Additionally, the study of fracture is correlated to the findings of inspection with different non-destructive techniques. The effect of tubes design (geometry, shape, material) on the fracture toughness is studied leading to the most promising healing system

Relationship between Young's modulus and temperature in porcelain tiles

A focused research was conducted on samples prepared from an industrial porcelain tile composition containing quartz, used to produce ceramic floor tiles, with the aim of evaluating the variation of fired specimens’ Young's modulus with temperature. These samples were fired in controlled laboratory conditions so that specimens with pre-existing cracks were obtained and subject to non-destructive in situ thermo-mechanical measurements (impulse excitation technique) in the 22–700 °C temperature range during heating and cooling processes in order to find evidences to explain the hysteresis phenomenon in the Young's modulus versus temperature curve. The observed irreversible Young's modulus may be directly related to the pre-existent cracks that on heating and cooling are closed and opened up respectively, changing thus the Young's modulus which is well characterized by a hysteresis cycle

Tunneling times in a taut string

The mathematical analogy of classical and matter waves can help to teach the elusive subject of tunneling times in undergraduate physics courses. The tunneling of mechanical energy through a taut string is revisited in this paper in order to study tunneling times for this classical system. General properties of the group delay, the dwell time and the interference time are described. Moreover, we explain how to build string arrays with piecewise constitutive parameters that behave like quantum mechanical heterostructures with alternating well and barrier layers. The paradoxical Hartman effect is also analyzed

Comprehensive Analysis of Antioxidant Compounds from Lippia citriodora and Hibiscus sabdari a Green Extracts Attained by Response Surface Methodology

Phenolic compounds have shown to have a high bioactive potential against various pathologies, postulating as an interesting alternative to manage some diseases. In this sense, both Lippia citriodora and Hibiscus sabdari a are two botanical sources with a demonstrated high bioactive potential, in which their antioxidant capacity stands out. In this work, the optimization of the extraction conditions for the recovery of phytochemicals from L. citriodora leaves and H. sabdari a calyces has been carried out using Response Surface Methodologies (RSM) considering their total polar compounds measured by HPLC-ESI-TOF/MS and Folin-Ciocalteu assay, and its antioxidant capacity evaluated by Ferric Reducing Antioxidant Power (FRAP) and Trolox Equivalent Antioxidant Capacity (TEAC) assays. The results showed that to maximize the antioxidant capacity in H. sabdari a, a moderate temperature and high ethanol percentage are needed, while a low temperature and a high percentage of ethanol are needed in L. citriodora. In addition, with the results obtained in the multiple response analysis, it is possible to a rm the importance of this type of analysis to develop functional ingredients, taking into account both total content of phenolic compounds and their bioactivity. Furthermore, as confirmed in this study, these analyses can be extrapolated in di erent techniques and in di erent matrices, with phenolic compounds from di erent families being important to develop new high added value products for food, pharmaceutical or cosmetic industries.Ministry of Science, Innovation and Universities RTI2018-096724-B-C22Plan Propio de Investigación of the University of GranadaMinistry of Science, Innovation and UniversitiesUniversity of GranadaAGR274 group 5450Spanish Ministry of Economy and Competitiveness (MINECO) BES-2016-07661

Amoxicillin and Clarithromycin Mucoadhesive Delivery System for Helicobacter pylori Infection in a Mouse Model: Characterization, Pharmacokinetics, and Efficacy

Helicobacter pylori is the main pathogen responsible for gastric ulcers and a predisposing factor of stomach cancer. Although current treatment is usually successful, it requires high doses and frequent administration. An innovative mucoadhesive system (Mucolast®) loaded with amoxicillin and clarithromycin is proposed to improve the efficacy of treatment against H. pylori. The drug product was optimized based on its viscoelastic properties to obtain long-term stability of the vehicle. The drug release mechanisms were different for both antibiotics based on their solubilization status. A systemic and stomach pharmacokinetic profile was obtained after three different doses were administered to mice, obtaining similar systemic exposure levels but an increase in drug concentration in the stomach. The efficacy results in mice infected with H. pylori also demonstrated the superiority of the antibiotics when administered in Mucolast®, as shown by the bacterial count in stomach tissue and under histopathological and biochemical evaluation. The proposed treatment was efficacious and safe and is presented as a realistic alternative to current treatment options to improve patient compliance and to reduce bacterial resistance.Ministerio de Ciencia e Innovación. Gobierno de España (programa RETOS)-RTC-2015-4437-

Plant growth promotion in cereal and leguminous agricultural important plants: From microorganism capacities to crop production

Plant growth-promoting rhizobacteria (PGPR) are free-living bacteria which actively colonize plant roots, exerting beneficial effects on plant development. The PGPR may (i) promote the plant growth either by using their own metabolism (solubilizing phosphates, producing hormones or fixing nitrogen) or directly affecting the plant metabolism (increasing the uptake of water and minerals), enhancing root development, increasing the enzymatic activity of the plant or “helping” other beneficial microorganisms to enhance their action on the plants; (ii) or may promote the plant growth by suppressing plant pathogens. These abilities are of great agriculture importance in terms of improving soil fertility and crop yield, thus reducing the negative impact of chemical fertilizers on the environment. The progress in the last decade in using PGPR in a variety of plants (maize, rice, wheat, soybean and bean) along with their mechanism of action are summarized and discussed here