Open Access
The integration of mechanical energy absorbers into rollover protective structures to improve the safety of agricultural tractors in the event of rollover
(MDPI, 2024) Alfaro López, José Ramón; Pérez Ezcurdia, Amaya; Latorre Biel, Juan Ignacio; Arana Navarro, Ignacio; Benito Amurrio, Marta; Villanueva Roldán, Pedro; Ingeniería; Ingeniaritza; Institute of Smart Cities - ISC; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, PJUPNA1912
The combination of safety belts and rollover protective structures (ROPSs) is key in improving the safety of agricultural tractors in the event of rollover. However, we also have the opportunity to enhance the security provided by each ROPS; one such example is the combination of this safety device with adequate mechanical energy absorbers (MEAs). Inexpensive disc-shaped MEAs can be included in the anchoring points of a ROPS onto the chassis of a tractor. Three configurations of ROPS combined with MEAs were tested during the application of loads that simulated the effects of side rollover in the vehicle. The tested configurations included a blank MEA as a reference case alongside a single MEA and a stack assembly containing both elements. The results of the tests show that both the deformation of the ROPS itself and the strain energy are larger in the case of blank MEAs; thus, there is also a risk that the clearance zone will be infringed upon and that the protective structure will collapse. We can conclude that the implementation of an appropriate MEA in ROPS reduces the deformation of the ROPS itself and its strain energy in cases of vehicle rollover; hence, the safety provided by such protection systems may be improved at a low cost.
Open Access
Tacit contributions and roles of senior researchers: experiences of a multinational company
(MDPI, 2022) Pérez Villa, Walter; Pérez Ezcurdia, Amaya; Vigil Berrocal, Miguel Angel; Ingeniería; Ingeniaritza
One of the concerns of innovation-dependent organisations is that the gradual increase in the average age of their employees might affect their creativity and innovation rates, leading to losses in competitiveness. The purpose of this paper was to deepen the identification and understanding of the contributions done by senior researchers within a private organisation. This study was based on field qualitative research on a multinational company. Interviews were performed were senior researchers and the transcripts were analysed with a qualitative data analysis (QDA) software to organise, analyse and find insights in unstructured or qualitative data. Analysis was performed using axial coding, which relates data together to reveal codes and categories from participants¿ voices within the collected data. The points of view of senior researchers were explicitly sought and the findings indicated that these veteran professionals can be more valuable for their contributions as experienced workers than for their scientific productivity at the individual level, without disregarding it. Senior researchers have acquired tacit skills linked to their experience, such as a holistic view of the issues and efficient work methodologies. Therefore, they develop formal or informal roles over time related to advice and knowledge transfer. Consequently, it was found that their tacit contributions and roles increase the intellectual capital of the organisation. This paper helps in understanding the contributions made by senior researchers within a private organisation. No other reviews have sought to obtain such information on this specific sector.
Open Access
The project book: a toolkit for stakeholder management in international development projects
(Universidad de Zaragoza, 2024-10-24) Romero de Miguel, Aida; Pérez Ezcurdia, Amaya; Gimena Ramos, Faustino; Ingeniería; Ingeniaritza; Sociología y Trabajo Social; Soziologia eta Gizarte Lana
En este artículo, se presenta una metodología de gestión de proyectos de cooperación internacional al desarrollo diseñada para agentes deslocalizados que, sobre una base tradicional de gestión de proyectos (fases y procesos), añade un sistema documental abierto (libro del proyecto) y la aplicación de técnicas de investigación-acción participativa. El libro del proyecto mejora la transparencia y, por tanto, la confianza y el compromiso. Con las técnicas de investigación-acción participativa, se apoya la gestión intercultural de los agentes de los proyectos. La metodología ha sido probada en tres sectores -«salud», «producción» y «educación»-, ejecutados en Colombia. La calidad y el éxito del proyecto tras su aplicación se caracteriza por una aceptación del 80 % de los agentes.
Open Access
Feasibility of vermicomposting of spent coffee grounds and silverskin from coffee industries: a laboratory study
(MDPI, 2020) González Moreno, Miguel Ángel; Marcelino Sádaba, Sara; Zaratiegui Urdin, Javier; Robles Domínguez, Estrella; Pérez Ezcurdia, Amaya; Seco Meneses, Andrés; Ingeniaritza; Institute of Smart Cities - ISC; Ingeniería; Gobierno de Navarra / Nafarroako Gobernua, VERMICOMPOSTAJE 4.0-VERMIOT (0011-1365-2019-000110)
In the coffee industry, several by-products are generated during the production and consumption of coffee and represent an important waste from an environmental viewpoint. For improving the knowledge about this issue, a laboratory vermicomposting study of coffee silverskin (CS) and spent coffee grounds (SCG) spiked with mature horse manure (HM) in different proportions and using earthwormEisenia andreiwas carried out. The 60-day study focused on biological parameters such as total biomass gain, growth rate, cocoon production, and mortality. This study also investigated whether the vermicompost obtained could be useful and lacked toxicity through a seed germination test using hybrid wheat seeds. Results showed a disparity depending on the type of residue and the mixture used. Best options were those treatments with a medium-low amount of residue; 25% for SCG and 25% or 50% for CS. In addition, lack of toxicity was confirmed in all treatments. In conclusion, it is possible to carry out a vermicomposting of SCG and CS with some specific features.
Open Access
Influence of geometry in the behavior of disc-shaped mechanical energy absorbers for agricultural tractors
(MDPI, 2021-12-20) Latorre Biel, Juan Ignacio; Pérez Ezcurdia, Amaya; Benito Amurrio, Marta; Alfaro López, José Ramón; Ingeniería; Ingeniaritza; Institute of Smart Cities - ISC; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, PJUPNA1912
Disc-shaped mechanical energy absorbers (MEAs), in combination with rollover protection structures (ROPSs), may contribute to the prevention of the infringement of the safety zone and the collapse of the ROPS in case of the overturn of an agricultural tractor. An MEA can absorb a significant amount of potential energy of an overturning tractor and its deformation produces a rotation of the ROPS around the safety zone. In this research, MEAs with two different geometries have been developed. Both geometries present common features, such as disc dimensions, number of rings, and number of arms, but the distribution of the arms differs. Additionally, these MEA were manufactured in steel discs of four different thicknesses, ranging from 2 to 6 mm. The manufactured MEAs were tested in a universal testing machine, and their behavior characterized. From this data, linear models of the MEAs were developed. As a consequence, a number of characteristic parameters were selected and calculated, such as the activation load and the strain energy absorbed in a safe range of applied loads. Some patterns and trends were analyzed from the tested MEAs, which enables a better description of their behavior and the extrapolation of this behavior to other non-tested thicknesses and geometries.