Teaching materials in the 21st century

We live in an era of continuous change. In the branch of engineering, beyond the usual and pressing objectives of functionality, safety and integrity, computers are now used pervasively, new economic pressures and concern for the environment are looming, and the availability of energy resources and proper functioning of materials supply chains are ever more important. Students need an education that allows them to understand and deal with these changes, in a time when growth in the number of students, expectations and pressure on teaching resources is a challenge for professors, particularly for younger academics. Engineers create things out of materials. What do engineering students need to know to select and use materials that perform as expected, are safe, economically efficient and have the least environmental impact? This question leads to the introduction of the design approach. Knowledge, data and tools are necessary for students to make decisions that meet complex design requirements. This means that science is introduced in a way that facilitates understanding how to meet design requirements and select materials and processes. This paper also introduces briefly some of the new aspects of the 2012 CES EduPack. This tool developed by Granta Design, supports professors and helps students of both introductory and advanced courses in branches such as engineering, design and science in the study of materials. CES EduPack is used in more than 850 universities and institutes around the world and is continually evolving to offer a new version each January. Changes and new features are focused on two pathways, one active (eg development of Eco Selector and Eco-audit tool) and another in response to feedback from users. The latter has made the software more intuitive and easy to use.Peer Reviewe

Triaxial tests on frozen ground: formulation and modelling

Artificial Ground Freezing (AGF) is a controllable process that can be used by engineers to stabilise temporarily the ground, provide structural support and/or exclude groundwater from an excavation until construction of the final lining provides permanent stability and water tightness. In this work, the process of ground freezing is studied using a constitutive model that encompasses frozen and unfrozen behaviour within a unified effective-stress- based framework and employs a combination of ice pressure, liquid water pressure and total stress as state variables. The parameters of the constitutive model are calibrated against experimental data obtained from samples retrieved during construction of Napoli underground, in which AGF was extensively used to excavate in granular soils and weak fractured rock below the ground water table.Postprint (published version

Artificial ground freezing of a volcanic ash: Laboratory tests and modelling

The use of artificial ground freezing (AGF) to form earth support systems has had applications worldwide. These cover a variety of construction problems, including the formation of frozen earth walls to support deep excavations, structural underpinning for foundation improvement and temporary control of ground water in construction processes. On one hand, the main advantage of AGF as a temporary support system in comparison to other support methods, such as those based on injections of chemical or cement grout into the soil, is the low impact on the surrounding environment as the refrigerating medium required to obtain AGF is circulated in pipes and exhausted in the atmosphere or re-circulated without contamination of the ground water. On the other hand, the available methods may vary significantly in their sustainability and complexity in terms of times and costs required for their installation and maintenance. The ability to predict the effects induced by AGF on granular materials is therefore crucial to assessing construction time and cost and to optimising the method. In this work, the thermo-hydro-mechanical processes induced by artificial freezing of a soil body are studied using a constitutive model that encompasses frozen and unfrozen behaviour within a unified effective-stress-based framework. It makes use of a combination of ice pressure, liquid water pressure and total stress as state variables. The model is validated and calibrated using the results of a series of laboratory tests on natural samples of a volcanic ash (Pozzolana) retrieved during construction of Napoli underground, where the technique of AGF was used extensively to stabilise temporarily the ground and control the ground water

Local flexibility market design for aggregators providing multiple flexibility services at distribution network level

This paper presents a general description of local flexibility markets as a market-based management mechanism for aggregators. The high penetration of distributed energy resources introduces new flexibility services like prosumer or community self-balancing, congestion management and time-of-use optimization. This work is focused on the flexibility framework to enable multiple participants to compete for selling or buying flexibility. In this framework, the aggregator acts as a local market operator and supervises flexibility transactions of the local energy community. Local market participation is voluntary. Potential flexibility stakeholders are the distribution system operator, the balance responsible party and end-users themselves. Flexibility is sold by means of loads, generators, storage units and electric vehicles. Finally, this paper presents needed interactions between all local market stakeholders, the corresponding inputs and outputs of local market operation algorithms from participants and a case study to highlight the application of the local flexibility market in three scenarios. The local market framework could postpone grid upgrades, reduce energy costs and increase distribution grids’ hosting capacity.Postprint (published version

Fate of MTBE and DCPD Compounds Relative to BTEX in Gasoline-Contaminated Aquifers

The aim of this communication is to provide preliminary results on MTBE monitoring, and at the same time to propose some new tracers of gasoline pollution in groundwater. An overview is presented on benzene-toluene-ethylbenzene-xylene (BTEX), methyl tertiary-butyl ether (MTBE), and dicyclopentadienes (DCPD) contents in gasoline formulations. Their specific fate in gasoline-contaminated aquifers are consistent with their physical-chemical properties

The Inclusionary Populist Communication Style on Facebook: The Case of Ada Colau in Barcelona

Communication is one of the core elements of populism, especially in social media. Through such digital platforms, political leaders can communicate directly with citizens and build both their discourse and their political leadership. Although the literature has so far identified the existence of a populist political communication style, the expansion of populism and its connection with social media are extending and diversifying the concept, as well as adding new repertoires. In order to analyse this, we propose a study of the communication strategy of the mayor of Barcelona, Ada Colau who, with a background of citizen activism, became mayor of the city in 2015 thanks to a political organisation situated as left populist. The methodology is based on quantitative and qualitative analysis of the content of Colau’s Facebook profile. A total of 226 posts between 2015 and 2017 are analysed. The results make it possible to identify a new specific modality within the populist style of political communication, namely the inclusionary populist type. This focuses on issues related to defense of the rights of the weakest social groups and works within a framework of social justice and solidarity with others. Likewise, the study confirms how Facebook is configured as a preferred platform for the construction of political leadership

A hydro-geochemical analysis of the saturation process with salt water of a bentonite crushed granite rock mixture in an engineered nuclear barrier

A MX-80 sodium bentonite crushed granite rock mixture is being saturated in the Äspö Hard Rock Laboratory managed by SKB (the Swedish Company of nuclear waste management) as part of the “Backfill and Plug Test Project”. The Äspö Hard Rock Laboratory is placed in the Swedish Island of Äspö, an underground full-scale laboratory where different testing construction procedures and handling techniques are being studied. The groundwater of Äspö has a variable salt concentration according to the zone considered. The added water during the mixing process of both materials had an average salt concentration of 6 g/L. However, backfill is being saturated with salt water containing higher salt content (up to 16 g/L, 50 / 50 of NaCl and CaCl2 by mass) to speed up the saturation process. The mixture swelling capacity is small due to the low backfill bentonite content, but its activity is still large if compared with natural clayey soils. A coupled hydro-chemical approach was used to simulate the backfill hydration process, comparing the results with in situ measurements. An intrinsic permeability law, depending on salt concentration in the liquid phase, was incorporated into the model. The retention curve was also determined taking into account the effect of the chemical species on backfill behaviour. The simulation of the saturation process shows the importance of studying these problems with a HC (hydro-chemical) formulation, especially if long term behaviour of such mixtures is going to be reproduced

Escala NEDOCS para medir congestión en urgencias: estudio de validación en Colombia

Introducción: En Colombia, no existe una herramienta para cuantificar el grado de congestión de los servicios de urgencias que sea aplicable a su realidad. Por esta razón, este trabajo busca determinar si la escala NEDOCS es una herramienta válida para medir el grado de congestión en este medio. Métodos: Se calculó la escala durante un período de tres semanas, durante 6 veces en el día a la misma hora en las tres instituciones. Para la validación, se comparó la escala NEDOCS contra dos escalas tipo Likert de 6 preguntas. Además, se describió el porcentaje de la demanda no atendida y del número de quejas. Resultados: Para la escala, la variabilidad se explica en 88 %. Por otro lado, la correlación entre la severidad en la congestión de los últimos 3 ítems de la escala con las opiniones subjetivas fue directa y significativa (r = 1,000., p < 0.000). Se obtuvo una correspondencia significativa con las siguientes variables: a) disponibilidad de camas (r = 0.7, p < 0.001); b) promedio de tiempo de espera, (r = 0,56, p < 0.021). Discusión: Dado que no existe gold standard, las mediciones de la escala en comparación con las opiniones del personal arrojan que la escala NEDOCS aplicada en los servicios de urgencias colombianos es útil para medir congestión. Se observó como fenómeno especial que el personal se encuentra acostumbrado a vivir con la congestión, por lo cual el personal considera como congestión del servicio los momentos de alto stress laboral.Introduction: In Colombia, there isn´t a tool to quantify the degree of congestion of the emergency services that apply to your reality. For this reason, this work seeks to determine if the scale NEDOCS is a valid tool to measure the degree of congestion in this environment Methods: We estimated the scale during a period of three weeks for 6 times a day at the same time in the three institutions. For validation, we compared the level NEDOCS against two Likert scales of 6 questions. In addition, he described the percentage of unmet demand and the number of complaints. Results: For the scale, the variability is explained by 88%. On the other hand, the correlation between the severity of congestion in the last 3 items of the scale with the subjective opinions was direct and significant (r = 1.000., P <0.000). We obtained a significant correspondence with the following variables: a) availability of beds (r = 0.7, p <0,001); b) Average waiting time (r = 0.56, p <0.021). Discussion: Since there is no gold standard, measurements of the scale compared to the views of staff NEDOCS show that the scale applied in the emergency department Colombians is useful to measure congestion. Special phenomenon was observed that staff are accustomed to "live with congestion, so the staff considers as congestion of the service times of high work stress

New aspects in cardiorenal syndrome and HFpEF

Cardiorenal syndrome; Chronic renal failure; DiureticsSíndrome cardiorrenal; Insuficiencia renal crónica; DiuréticosSíndrome cardiorenal; Insuficiència renal crònica; DiürèticsCardiorenal syndrome (CRS) is a complex disease in which the heart and kidneys are simultaneously affected, and subsequently, the malfunction of one organ promotes the deterioration of the other. Heart failure (HF) with preserved ejection fraction (HFpEF) is the most common form of HF. The pathophysiology of CRS is not well known and several mechanisms have been proposed. An elevation of central venous pressure seems to be one of the key points to consider, among others such as an increase in intraabdominal pressure. Several diagnostic tools have been identified to establish the diagnosis of CRS in patients with HFpEF. Currently, the availability of biomarkers of renal and cardiac injury, the use of pulmonary ultrasound, the monitoring of the size of the inferior vena cava and the study of the renal venous pattern offer a new dimension in accurately diagnosing and quantifying organ damage in CRS. Beyond the symptomatic treatment of congestion, until recently specific therapeutic tools for patients with CRS and HFpEF were not available. Interestingly, the development of new drugs such as the angiotensin/neprilysin inhibitors and sodium-glucose cotransporter-2 (SGLT-2) inhibitors offer new therapeutic strategies with potential benefits in reduction of cardiorenal adverse outcomes in this population. Randomized clinical trials that focus on patients with HFpEF are currently ongoing to delineate optimal new treatments that may be able to modify their prognosis. In addition, multidisciplinary teamwork (nephrologist, cardiologist and nurse) is expected to decrease the number of visits and the rate of hospitalizations, with a subsequent patient benefit