Towards a Global Solvency Model in the Insurance Market: A Qualitative Analysis

In recent years, there has been a change in the main regulations governing the solvency of the world’s main insurance markets. Sustainability is an issue that is becoming increasingly important among to the various stakeholders in the insurance industry. It is a complex concept that has many different dimensions that can be included in these regulations, allowing for a more sustainable solvency. The paper uses a qualitative model previously designed and tested in the literature to analyse the solvency regulations of the European Union, United States of America, China, Australia, Brazil and South Africa and determine their level of convergence. It also links the criteria set out in these models to the dimensions of sustainability in order to determine the degree of sustainability of solvency systems and the questions that regulators will need to consider in the near future in order to achieve more sustainable solvency.This research was funded by Consolidated Research Group Eusko Jaurlaritza/Gobierno Vasco EJ/GV grant number IT1523-22

Performance of rGO/TiO2 photocatalytic membranes for hydrogen production

Although there are promising environmental and energy characteristics for the photocatalytic production of hydrogen, two main drawbacks must be overcome before the large- scale deployment of the technology becomes a reality, (i) the low efficiency reported by state of the art photocatalysts and, (ii) the short life time and difficult recovery of the photocatalyst, issues that need research and development for new high performance catalysts. In this work 2% rGO/TiO2 composite photocatalysts were supported over Nafion membranes and the performance of the photocatalytic membrane was tested for hydrogen production from a 20% vol. methanol solution. Immobilization of the composite on Nafion membranes followed three different simple methods which preserve the photocatalyst structure: solvent-casting (SC), spraying (SP), and dip-coating (DP). The photocatalyst was included in the matrix membrane using the SC method, while it was located on the membrane surface in the SP and DP membranes showing less mass transfer limitations. The performance of the synthesized photocatalytic membranes for hydrogen production under UVA light irradiation was compared. Leaching of the catalytic membranes was tested by measuring the turbidity of the solution. With respect to catalyst leaching, both the SC and SP membranes provided very good results, the leaching being lower with the SC membrane. The best results in terms of initial hydrogen production rate (HPR) were obtained with the SP and DP membrane. The SP was selected as the most suitable method for photocatalytic hydrogen production due to the high HPR and the negligible photocatalyst leaching. Moreover, the stability of this membrane was studied for longer operation times. This work helps to improve the knowledge on the application of photocatalytic membranes for hydrogen production and contributes in facilitating the large-scale application of this process.This research was funded by MCIU/AEI/FEDER UE (RTI2018-099407-B-I00, RTI2018-093310-B-I00 and RTC2019-006820-5)

Microrheology Of Gels Based On Polymers And On Different Colloidal Systems

Gels are ubiquitous materials in Biology and in many technological fields such as cosmetics, pharmacy, food, science. A distinctive feature of gels is their mechanical properties, which are intermediate between those of concentrated polymer solutions and of rigid solids. Focusing on the complex shear modulus, G*, the gelling point at a given temperature is frequently defined as the frequency at which the real, G’, and the imaginary, G”, contributions are equal. Understanding the gelling kinetics is another issue of key importance for designing gels under pre-specified conditions. A short cut in most papers G* is measured in a short low-range frequencies. Passive microrheology is a good tool for extending the frequency range. Despite it is only useful for the linear range, it has the advantage of enabling to probe the spatial heterogeneity. In this communication we will use passive microrheology and standard low-frequency rotational rheology to study the gelling kinetics of concentrate polysaccharide solutions at different concentration and temperatures. It has been found that the use of the extended Jeffrey’s model fits the results and allows one to calculate the short- and long-time node-node diffusion coefficients and mean node-node molecular weight. It was found that the mean-squared displacement does not only depends on the size of the particles, but also on their chemical nature because in some cases, e.g. TiO2, there can be strong particle-monomer interactions that slow down the motion of the microparticles. Similar studies have been done using gels based on colloidal systems such as lamellar phases or emulsions, including active molecules or not. More sophisticated systems are nano- or microgels inside liposomes or giant vesicles. In this case hyaluronic acid is encapsulated and then crosslinked by Fe3+ ions that diffuse through the phospholipidic membrane. In this case a heterogeneous gelling process takes place due to the gradient of Fe3+ ions from the membrane to the center of the capsule. Finally, gel-like materials are formed by adsorption of polyelectrolytes or their mixtures with surfactants from their aqueous solutions on solid substrates. Their mechanical properties at high frequencies can be estimated using a quartz-crystal microbalance with dissipation. In most cases the values of G’ are in the MHz range despite the water content inside the adsorbed film can vary between 20 and 70 wt%. Despite it is possible to follow the adsorption kinetics, the precision on G’ does not allow following the gelling kinetics in terms of the shear modulus

Axisymmetric plasma plume characterization with 2D and 3D particle codes

The expansion of a rarefied axisymmetric plume emitted by a plasma thruster is analyzed and compared with a 3D Cartesian-type and a 2D cylindrical-type simulation code, both based on a particle-in-cell formulation for the heavy species and a simple Boltzmann-type model for the electrons. The first part of the paper discusses the 2D code numerical challenges in the moving of particles, their generation within the cells, and the weighting to the nodes, caused by the radial non-uniformity and the singular and boundary character of the symmetry axis. The second part benchmarks the 2D code against the 3D one for a high-energy, unmagnetized plume with three major species populations (injected neutrals, singly-charged and doubly-charged ions) and three minor species populations (constituted by particles coming from collisional processes, such as the charge-exchange reactions). The excellent agreement found in the results proves that both plume codes are capable of simulating, with a reasonable noise level, heavy particle populations differing by several orders of magnitude in number density. For simulations with a comparable level of accuracy, the 2D code presents a ten-fold gain in computational cost, although the symmetry axis remains its weakest point, due to particle depletion there and the related weighting noise

On heavy particle-wall interaction in axisymmetric plasma discharges

The effects of heavy particle-wall interaction on a cylindrical plasma source discharge are investigated, through hybrid particle-in-cell/fluid simulations. The bulk plasma is considered quasineutral with isothermal electrons, and with no secondary electron emission from the walls. The neutral gas wall reflection model is shown to play a major role in determining the conditions for a self-sustained and stationary plasma discharge. A hysteresis cycle on the injection mass flow rate is found when neutrals deviate from a purely diffuse reflection at the walls, with the mass utilization efficiency changing up to 20% between purely specular and diffuse scenarios. However, as the ratio of ionization mean free path to macroscopic length is decreased, the neutral-wall reflection model becomes irrelevant. Finally, even small deviations from unity of the ion energy accommodation coefficient at the walls are seen to have a major impact on both the ion and neutral distribution functions, and ultimately the mass utilization efficiency. This behavior stresses out the importance of a precise experimental determination of this parameter for accurate simulations.This paper has been funded mainly by Comunidad de Madrid/FEDER/FSE, through the PROMETEO-CM project, Grant No. Y2018/NMT-4750. Additional support came from the ESPEOS project, funded by the Agencia Estatal de Investigación (Spanish National Research Agency), under Grant No. PID2019-108034RB-I00/AEI/10.13039/501100011033

Implementación de un sistema integrado de tratamiento de aguas residuales como aporte para la descontaminación de la cuenca del Rio Chicamocha

El presente documento tiene como propósito fundamental determinar la viabilidad técnica, económica y ambiental de la implementación de una planta para el tratamiento de aguas residuales en el municipio de Sogamoso, como solución parcial a la contaminación de la cuenca del río Chicamocha. Dentro del documento se menciona la situación actual del tratamiento de estas aguas en el municipio, además se define que es una planta de tratamiento de aguas residuales, y se indican los objetivos principales y secundarios del proyecto así como su justificación. Se explica el aspecto técnico del proyecto, se describe el proceso de tratamiento de las aguas, y se indican los diferentes componentes de la planta de tratamiento a desarrollarse, adicionalmente se indica la localización del proyecto. Adicionalmente se analiza el aspecto económico y financiero, detallando los diferentes rubros de los cuales depende el proyecto, como son inversiones, costos operativos, rentabilidad, etc., también se determina la factibilidad financiera mediante un análisis económico y financiero. Se indica el impacto ambiental, donde se muestran los diferentes beneficios para la cuenca del río Chicamocha y el municipio de Sogamoso. Finalmente se presentan las conclusiones y recomendaciones, así como la bibliografía empleada. Este documento pretende ser una aportación importante para la planeación y la toma de decisiones de actores locales y regionales para el tratamiento de aguas residuales.This document has as main goal, to determine the technical, financial and environmental viability of the implementation of a wastewater treatment plant, in the municipality of Sogamoso, as a partial solution to the pollution of the Chicamocha river basin. The document shows the current state of the wastewater treatment in the town, also the definition of a Wastewater treatment plant, and the main and secondary goals of the project as well as its justification. The technical issues are explained, the definition of the wastewater treatment process and indicates the components of the plant to be developed, besides the location of the project is shown. Besides, the economic and financial assessment is analyzed, detailing the different sources of which the project depends on, as investments, operational costs, profitability, etc. Also the financial viability is determined through an economic and financial analysis. The environmental impact is indicates, showing the different benefits for the Chicamocha s river basin and the municipality of Sogamoso. Finally the conclusions and recommendations are presented as well as the literature consulted. This document is intended to be an important contribution to the planning and the decision making of the local and regional authorities of the wastewater treatment

Tratamientos de aguas residuales municipales y su impacto ambiental sobre un ecosisitema

El tratamiento de aguas residuales comprende una serie de procesos que permiten el saneamiento de las aguas después de su uso con fines domésticos, industriales y / o comerciales, para poder ser vertidas finalmente a cuerpos de agua naturales. Los procesos incluyen un pretratamiento y tres tratamientos secuenciales. En el pretratamiento se separan físicamente materias gruesas; en el tratamiento primario se eliminan sólidos en suspensión y material flotante por procedimientos físico-químicos; en el tratamiento secundario se efectúa la estabilización biológica del material biodegradable y en el tratamiento terciario se elimina el material que no haya sido removido en los procesos anteriores