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The reconfiguration of transport in the energy transition
No full textThe configuration of current civilization would not be conceivable without abundant and cheap transport: the dominant trends of recent decades such as the globalization of the economy, the segmentation of productive processes in distant places, the metabolism of large cities fueled by distant resources or mass tourism, would not have been possible.
During the first two decades of the 21st century, world passenger transport has grown like population (26.5%), but world freight transport has more than doubled (115% increase) to reach 53 tkm/ hab/day (tons x km per inhabitant and day). The characteristics of oil and its derivatives (gasoline, diesel, kerosene and fuel oil), with high energy densities (around 10 kWh/kg and around 8 kWh/litre), rapid recharge and artificially low costs by not including outsourcing, have led to a close correlation with transport and its growth: today 95% of transport (land, sea, air) is powered by petroleum products and 75% of oil is used for transport.
Electricity, the main renewable energy vector in the transport of the future, represents a substantial improvement in the performance of the driving elements but requires important power systems (storage in batteries, hydrogen and fuel cell, electrified catenary) that will be necessary implement to reconvert the centralized system of obtaining and distributing fossil fuels to mostly distributed systems of electric energy and hydrogen. It is necessary to rule out the obtaining of biofuels from crops, in collision with food and of very low yields, and limit them only to small amounts obtained from waste.
The transition in transport, based on renewable energy vectors and in the framework of sustainable development, will bring important changes and limitations with respect to some of the characteristics and uses we are used to today with oil, but also advantages and new possibilities. The purpose of this communication is to analyse these issues and explore the incidence of renewable transport in the current dominant trends and in the sustainable development of the futur
Uses of materials and energy on a finite earth
No full textIn terms of energy, the Earth is an open system: it constantly receives energy from solar radiation and emits the same amount of energy in the form of more degraded radiation; the displacement of the equilibrium point between these two flows due to the growth of greenhouse gases, increases the average temperature of the Earth and causes climate change. On the other hand, in relation to matter, the Earth is a closed system, apart from the sporadic fall of some meteor. Nature has the ability to regenerate the organic materials of living beings but not with many other materials.
Today, the volume of materials involved in human activities is 12.5 tons per person per year (1.5 to 4 times more in rich countries): 25% of the total comes from biomass (including food), 15% are fossil fuels, 10% are metal ores, 42% are other minerals (mainly for construction) and 8% are recycled. On the other hand, obtaining and transporting materials worldwide requires more than 40% of the energy of the human system, a value that is growing with the use of increasingly rare, scarce and dispersed materials. The overexploitation of resources coupled with the increasing use of non-renewable energy resources (fossil fuels and uranium), with the consequent energy and climate crisis and the deterioration of the environment, leads both to a change in the energy model and to rethinking the practices today dominant of continuous economic growth and the linear economy based on extract-use-throw.
The purpose of this communication is, after presenting the figures on the global metabolism of materials, to reflect on some of the new attitudes and actions that will need to be adopted within the framework of sustainable development. By way of example, the following are cited: 1) Moderate, reduce, eliminate the use of materials where possible; 2) Extend the life of goods and material infrastructures; 3) Reuse, recover, recycle materials; 4) Return as much as possible biologically based materials, more recyclable; 5) Avoid, as far as possible, technologies based on rare or scarce materials; 6) Avoid the dispersion of materials in the environment (atmosphere, water, soil); 7) Encourage the use of local materials in order to minimize transport and its energy impact; 8) Take care of the quality and good health of basic resources: air, water and fertile soil
ANÁLISIS DE LA RENTABILIDAD SOCIOECONÓMICA EN PRO DE LA SALUD LABORAL Y LA SOSTENIBILIDAD EMPRESARIAL. La solución MIESES-OIT
No full textLos pequeños y medianos despachos profesionales de economistas ante el desafío de la información de sostenibilidad y su rol en el servicio integral a las pymes
No full textEstamos asistiendo a un cambio vertiginoso en la regulación europea de la información corporativa de sostenibilidad. Los avances que se están dando en Europa al respecto han servido además como revulsivo para el resto de las normas y marcos de referencia existentes sobre la materia. Además, el debate se extiende no sólo a la revelación de información de sostenibilidad, sino que implica también cambios en el concepto de información corporativa, que engloba a la información financiera. Si bien parecía que estas obligaciones informativas sobre cuestiones ambientales, sociales y de gobernanza quedaban restringidas al ámbito de las grandes empresas nada más lejos de la realidad, pues finalmente, de forma indirecta se ven afectas todas las empresas, sea cual sea su tamaño. Por lo tanto, las pymes y los profesionales que las asesoran en el ámbito de la contabilidad, fiscalidad y la información financiera en general, juegan un papel fundamental en el camino hacia la sostenibilidad. Por ello, aun no estando las pymes incluidas en el ámbito de obligatoriedad de la nueva directiva de información corporativa de sostenibilidad, se ha desarrollado una norma voluntaria para pymes no cotizadas que actualmente se encuentra en período de exposición pública hasta el próximo 21 de mayo de 2024. En este trabajo exponemos los principales puntos de interés acerca del proceso de desarrollo de esta norma voluntaria de información corporativa de sostenibilidad para pymes no cotizadas, la indudable importancia de los pequeños y medianos economistas en el campo de la información financiera y no financiera en este desafío, y los puntos más importantes de esta norma, sobre la que es importante tener una opinión para participar en el actual proceso de exposición pública abierto por el emisor de normas de información de sostenibilidad europeo, el European Financial Reporting Advisory Group (EFRAG).
 
High Fidelity Hydroelastic Analysis Using Modal Matrix Reduction
No full textStructural assessment is a main concern when designing and operating any sort of offshore structure. This assessment is meant to ensure that the structural integrity is preserved along the lifespan of the asset, withstanding the worst sea-states that will be encountered and making sure that the accumulated fatigue damage will not jeopardize its structural integrity neither. The purpose of this paper is to present a fast and reliable hydroelastic model. This model is based on time-domain tight-coupling of a three-dimensional FEM (finite element method) linear structural model and a three-dimensional FEM seakeeping hydrodynamics model. In order to reduce the computational cost of structural dynamic simulations, the high-fidelity structural solution is projected onto the modal basis to obtain the modal matrix system and to extend the response amplitude operators (RAO) to the modal responses (MRAO). From there, the number of structural degrees of freedom can be greatly reduced by retaining only those eigenmodes preserving most of the structural elastic energy. The use MRAOs and/or the large reduction in structural degrees of freedom allows us to: first, quickly analyse the large number of loadcases required on the design stage; and second, to implement a digital twin for structural health monitoring in operational conditions. The paper also presents an application case of the developed methodology
Application of two analytical CPTU solutions to sensitive clay in Québec
Get PDFA recent series of CPTU soundings in sensitive clay at the Louiseville Quebec test site has been published, allowing for the application of two closed-form analytical solutions based on: (1) effective stress limit plasticity and (2) hybrid cavity expansion-critical state methods. These are used for geoparameter interpretations including: effective stress friction angle, undrained shear strength, yield stress ratio, undrained rigidity index, and the coefficient of consolidation. Profiles of these soil parameters are compared with the benchmark values obtained from available series of previous and present laboratory testing programs at this site, including index testing, triaxial compression, and one-dimensional consolidation. Piezocone dissipation tests are used to assess the coefficient of consolidation which are validated by pressuremeter holding tests and lab oedometer tests. An empirical CPTU screening method identifies the Louiseville site as underlain by sensitive clay, versus a regular insensitive clay deposit, whereas soil behavior type charts using Q-F-Bq indicate the soils are either silt (zone 4) or regular clay (zone 3). The alternate screening method is verified by field vane and laboratory fall cone that show the clay is in fact sensitive (average St ≈ 22)
Collapse Risk Evaluation of Subsurface Cavities in Pavements of Full-Scale Test Roads
Get PDFIn order to solve the problem of subsurface cavities in urban areas, industry, government and academia carried out collaborative research over 2018-2020. In this joint research, analysis of existing cavity data, laboratory model experiments, numerical analysis, and full-scale field test, monitoring of the cavity in the road, etc. were conducted. In this study, a full-scale test road was constructed with artificial cavities installed to evaluate the risk of collapse in consideration of the road structure. A series of plate loading tests and falling weight deflectometer tests was conducted on the road surface above a cavity to understand the cavity behaviour. A surface wave survey was also conducted to evaluate the wave propagation on and around cavities. It was found to be reasonable to evaluate the collapse risk of subsurface cavities by the ratio of depth and width of cavities, in which the thickness of the pavement should be excluded from the depth
Use of Macroseismic Intensity Data to Validate the Ground Motion Prediction Model in Albania
Get PDFMacroseismic observations are a valuable tool, that can be used for the verification of site response and attenuation. Hence, in the framework of a bilateral project supported by Central European Investment Fund and with the extensive support of Global Earthquake Model Foundation to update the national seismic hazard model of Albania, intensity maps that contained more than 6000 macroseismic observations for 168 shallow (
Geotechnical Characterization of Dredged Material from Rio Grande’s Port, Brazil
Get PDFDredging works are essential to ensure navigability in Harbors and waterways. However, this crucial activity generates millions of tonnes of waste each year worldwide. Since the disposal of dredged material is responsible for several environmental impacts, entrepreneurs and engineers must find creative uses for it. Therefore, this study aims to characterize a local dredged material to assess its properties and suitability for geotechnical applications. With this knowledge, this paper presents a series of experimental tests on dredged material samples retrieved from Rio Grande's Port, Brazil. The experimental program includes determining Atterberg limits, sieve and sedimentation analysis, pH and SEM analysis, compaction curve, and unconfined compressive strength in a reconstituted state. The results showed that the material is sandy lean clay, with unfavourable strength characteristics for geotechnical work in a raw state. However, with the advent of chemical stabilization techniques, there is potential for enhancing its suitability for geotechnical applications. By exploring methods such as adding binders like lime or Portland cement, the material's strength and stability could be significantly improved, opening up possibilities for its utilization in various engineering projects. This study contributes valuable insights into the potential reclamation and beneficial reuse of dredged material, ultimately aiding in the sustainable management of harbor and waterway dredging operation
Evolution of fracture permeability in active clayey formations
Get PDFOpalinus Clay (OPA), a potential geological host formation for the disposal of high-level radioactive waste in Switzerland, is characterized by a low intrinsic permeability on the order of ~ 10-20 to 10-21 m2. Nonetheless, its effective permeability can increase significantly due to active fractures, which are influenced by factors such as fracture geometry, solid-liquid interaction, and stress conditions. The evolution of the permeability and geometry of such active fractures, particularly in rocks containing swelling clay minerals, is important for assessing the long-term safety of the repositories. Here we present the results of an experimental investigation focused on understanding the evolution of permeability in fractured OPA. We employed an advanced high-pressure triaxial system to evaluate gas permeability, followed by a phase where gas was replaced with synthetic water. We observed a three-order-of-magnitude reduction in apparent permeability as fractures evolved, primarily due to active clay minerals and the associated swelling deformations. Furthermore, we conducted a detailed analysis of the material's internal pore structure at each stage of the experiment using X-ray computed tomography. Results may be used to understand the underlying processes in the evolution of fracture permeability in clayey formations applied in hydrocarbon reservoirs, carbon sequestration, and nuclear waste containment