Thermodynamic, economic and environmental assessment of energy systems including the use of gas from manure fermentation in the context of the Spanish potential

One of the prospective technologies that can be used for energy generation in distributed systems is based on biogas production, usually involving fermentation of various types of biomass and waste. This article aims to bring novelty on the analysis of this type of systems, joining together thermodynamic, economic and environmental aspects for a cross-cutting evaluation of the proposed solutions. The analysis is made for Spain, for which such a solution is very promising due to availability of the feedstock. A detailed simulation model of the proposed system in two different cases was built in Aspen Plus software and Visual Basic for Applications. Case 1 involves production of biogas in manure fermentation process, its upgrading (cleaning and removal of CO2 from the gas) and injection to the grid. Case 2 assumes combustion of the biogas in gas engine to produce electricity and heat that can be used locally and/or sold to the grid. Thermodynamic assessment of these two cases was made to determine the most important parameters and evaluation indices. The results served as input values for the economic analysis and environmental evaluation through Life Cycle Assessment of the energy systems. The results show that the analysed technologies have potential to produce high-value products based on low-quality biomass. Economic evaluation determined the break-even price of biomethane (Case 1) and electricity (Case 2), which for the nominal assumptions reach the values of 16.77 €/GJ and 28.92 €/GJ, respectively. In terms of environmental assessment the system with the use of biogas in gas engine presents around three times better environmental profile than Case 1 in the two categories evaluated, i.e., carbon and energy footprint.This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 799439. Dr. Martín-Gamboa states that thanks are due to FCT/MCTES for the financial support to CESAM (UID/AMB/50017/2019), through national funds

Investigación educativa e investigación en educación matemática

El presente artículo teórico tiene como propósitos exponer el punto de vista de distintos autores sobre el concepto de educación; establecer la relación entre ciencias de la educación, pedagogía y educación; así como mostrar el papel que posee la filosofía de la educación en este proceso, y analizar el rol de la investigación en el campo de la educación y en la educación matemática. Se concibe la educación como un proceso permanente y dinámico que le brinda al individuo herramientas para su realización personal, el perfeccionamiento de este y su inserción en la sociedad al inculcarle reglas, comportamientos, conocimientos, contenidos escolares y valores, entre otros; acordes con el entorno cultural en cual se encuentra inmerso. Después de analizar la investigación en educación, se puede concluir que la investigación en educación matemática asume un rol preponderante para comprender el proceso de enseñanza y aprendizaje de la disciplina, el papel de las matemáticas en el desarrollo de los individuos y en el desarrollo científico de la sociedad. Se destaca, además, la importancia de una integración de los métodos cuantitativos y cualitativos para la comprensión del proceso de enseñanza y aprendizaje de las matemáticas

Concordance between introductory university mathematics courses and the program of pre-university studies: A view from the perspectives of content and academic performance

This article reports data about academic achievement in introductory university level mathematics courses taught by the Department of Mathematics at the Universidad Nacional de Costa Rica and the concord¬ance between the contents of these courses and those of pre-university (secondary education) programs. Information was collected by analyzing grades from introductory university mathematics courses for all programs of study in the period 2011-2016, the courses offered, and the program of studies in mathemat¬ics in secondary education. This was done to determine academic performance and to make comparisons between introductory mathematics courses at university level and the program of mathematics studies in secondary education, to stimulate revision and updating of the courses and generate recommenda¬tions. The results show that there are high failure and dropout rates in most introductory university-level mathematics courses, and that there are differences between the content that students study in secondary education and the content of introductory mathematics courses offered by the Universidad Nacional; prior knowledge is therefore relevant for academic achievement in introductory university mathematics courses. In addition, the data collected on content and aspects of methodology and evaluation show important differences in the way mathematical contents are addressed at each level. This implies that analysis of the contents of these courses should be carried out and strategies should be created, to guarantee a minimum level of prior knowledge in students when beginning the study of these subjects at university level

Combined use of Data Envelopment Analysis and Life Cycle Assessment for operational and environmental benchmarking in the service sector: a case study of grocery stores

Ensuring sustainable production patterns doing more and better with less is a key sustainable development goal. In this sense, the joint use of Life Cycle Assessment and Data Envelopment Analysis (i.e., the LCA+DEA methodology) arises as a quantitative tool for the eco-efficiency assessment of multiple similar entities. To date, the LCA+DEA methodology has been widely applied to case studies within the primary and secondary sectors. However, the applicability of this combined methodology to case studies within the tertiary (service) sector is still unexplored, which constitutes a current knowledge gap in this field. This work contributes to filling this gap by benchmarking the operational and environmental performance of a sample of 30 groceries located in Spain. All the evaluated groceries were found to involve relative efficiency scores above 0.60, with one third of the groceries deemed fully efficient. Average reductions of 3-26% in the consumption of operational inputs were calculated, leading to average reductions of 9% in the carbon footprint and 10% in the energy footprint. Furthermore, economic savings of up to 3% of the annual turnover were estimated. These results were further enriched through the application of a super-efficiency DEA model for a refined identification of the best-performers, as well as through the novel use of a specific model for the gradual operational and environmental benchmarking of the sample. Overall, a high applicability of the LCA+DEA methodology for eco-efficiency assessment within the service sector is concluded, facilitating the identification and quantification of sustainable operational patterns.publishe

Sustainability-oriented management of retail stores through the combination of life cycle assessment and dynamic data envelopment analysis

A sound management of retail stores is a crucial aspect in the path towards a sustainable commercial sector, with a lack of research studies in the field of joint efficiency and sustainability assessment within this sector. In this sense, this work delves into the role of operational efficiency in the sustainability-oriented management of retail stores through the case study of 30 groceries in Spain over the period 2015-2017. With this purpose, and given the current knowledge gap in period-oriented sustainability benchmarking for management plans, for the first time a five-step methodological framework based on the combination of Life Cycle Assessment (LCA) and dynamic Data Envelopment Analysis (DEA) was proposed and applied to a case study within the service sector. The overall- and term-efficiency scores calculated through this method led to the general conclusion of a relatively good performance of the set of grocery stores over the evaluated period, which is associated with the centralised management strategy followed by the retail company. Furthermore, operational, socio-economic and environmental benchmarks were calculated as target values that could assist decision-makers at the retail company level in setting the path for a sustainable operation of the company's stores. Overall, the proposed period-oriented LCA + DEA method proved to be a feasible and valuable tool for sustainability management of retail stores, being preferred over the static (i.e., single term) alternative provided that time-series data are available at the company level.publishe

Sustainability-oriented efficiency of retail supply chains: a combination of Life Cycle Assessment and dynamic network Data Envelopment Analysis

Assessing the efficiency of retail supply chains (RSCs) requires analytical tools that address the different activities involved in these chains. In this sense, dynamic network Data Envelopment Analysis (DEA) arises as a suitable method to evaluate the operational performance of RSCs over a period of time. However, its use for sustainability-oriented efficiency assessment constitutes a knowledge gap that limits its applicability for thorough decision-making processes, e.g. at the retail company level. This article fills this gap through the combination of Life Cycle Assessment (LCA) and dynamic network DEA. A novel five-step LCA + DEA approach is proposed and applied to a case study of 30 RSCs in Spain for the period 2015-2017. In this case, the supply chain structure involves three divisions: central distribution, operation of retail stores, and home delivery. Both overall- and term-efficiency scores were found to widely range from 0.38 to 1.00, with only 1 RSC deemed efficient. Regarding divisional efficiency, store operation was found to generally show significantly higher efficiency scores than the distribution divisions. The link between long distribution distances and low efficiency stresses the relevance of integrating a network perspective into the efficiency assessment. In addition to efficiency scores, the LCA + DEA approach enriches the assessment by providing environmental, operational and socio-economic benchmarks to further support the management of RSCs from a sustainability perspective.publishe

Sensitivity of operational and environmental benchmarks of retail stores to decision-makers' preferences through Data Envelopment Analysis

Within the framework of multi-criteria decision analysis (MCDA), weighting methods are typically used to capture decision-makers' preferences. In this regard, the increasing use of the combined LCA (Life Cycle Assessment) + DEA (Data Envelopment Analysis) methodology as an MCDA tool requires an in-depth analysis of how the preferences of decision-makers could affect the outcomes of LCA + DEA studies. This work revisits a case study of 30 retail stores/supply chains located in Spain by applying alternative weighted DEA approaches to evaluate the influence of decision-makers' preferences (weights) on the final outcomes, with a focus on efficiency scores and operational and environmental benchmarks. The ultimate goal is to effectively capture the view of stakeholders when applying LCA + DEA for the sound, sustainability-oriented management of multiple similar entities. Different weight vectors are separately applied to three types of DEA elements: operational inputs, time terms, and divisions. Besides, preferences from three alternative standpoints are considered: company manager through direct rating, and environmental policy-maker and local community through AHP (analytic hierarchy process). A significant influence on efficiency scores and sustainability benchmarks was found when weighting decision-makers' preferences on operational inputs. Additionally, a moderate influence was observed when weighting divisions according to a policy-maker or local community perspective. Although the results are case-specific, they lead to the general recommendation to enrich LCA + DEA studies by following not only an equal-weight approach but also approaches that include the preferences of the stakeholders effectively involved in the study.publishe

COSTO-EFECTIVIDAD DE AÑADIR EL PÉPTIDO NATRIURÉTICO TIPO B AL ÍNDICE DE LEE EN LA EVALUACIÓN

Se evalúa con un árbol de decisión la costo-efectividad de la adición del Péptido Natriuréticotipo B al índice de Riesgo Cardiaco Revisado de Lee en la valoración del riesgo cardiovascular en pacientes sometidos a cirugía mayor no cardiaca. La estrategia Lee =3 a un costo de Col $79.452 por paciente es costo efectiva para disponibilidades a pagar inferiores a Col$ 11.292.903 La estrategia de Lee con punto de corte 3 tiene el mejor perfil de costo-efectividad, sin embargo los resultados fueron muy sensibles a la probabilidad de eventos cardiovasculares.Economía de la salud, Péptido Natriurético Encefálico, Riesgo, Enfermedades Cardiovasculares, Análisis de costo-beneficio (Fuente DeCS: Bireme)

Propuesta de inclusión de un curso de neurofinanzas en la malla curricular del Instituto Tecnológico de Costa Rica.

Proyecto de graduación (Licenciatura en Administración de Empresas. Enfasis en Finanzas) Instituto Tecnológico de Costa Rica, Escuela de Administración de Empresas, 2014A partir de la década de 1990, se ha comenzado a desarrollar el tema de la neuroeconomía en las principales escuelas de negocios a nivel mundial, incorporando dentro de sus planes de estudios las diversas disciplinas que ésta encierra. Entre ellas se tienen las neurofinanzas, las cuales ha tenido un gran aporte en la toma de decisiones financieras. Debido a la importancia que las neurofinanzas han tomado, es que se procede hacer un análisis de las siete de las universidades más renombradas, en miras de conocer su situación actual. Se determinó que dichas universidades no contemplan las neurofinanzas dentro de sus planes de estudio o al menos no se evidencia la existencia de esta en sus mallas curriculares, por lo que se considera necesario hacer una propuesta de incorporación dentro de la malla curricular de la Licenciatura con énfasis en finanzas del Instituto Tecnológico de Costa Rica, considerando que dicha escuela de negocios es pionera en la educación costarricense. Se estudia un curso completo de neurofinanzas, el cual permite desarrollar una propuesta, con la que se recomienda sustituir uno de los cursos optativos por el de Neurofinanzas, el cual está compuesto de ocho módulos debidamente respaldados, tomando como base los propuestos por la Asociación Española de Neurofinanzas, esto por ser expertos en el tema y tener vínculos con el Instituto Tecnológico de Costa Rica