Carbon Footprint of a Port Infrastructure from a Life Cycle Approach.

One of the most important consequences caused by the constant development of human activity is the uncontrolled generation of greenhouse gases (GHG). The main gases (CO2, CH4, and N2O) are illustrated by the carbon footprint. To determine the impact of port infrastructures, a Life Cycle Assessment approach is applied that considers construction and maintenance. A case study of a port infrastructure in Spain is analyzed. Main results reflect the continuous emission of GHG throughout the useful life of the infrastructure (25 years). Both machinery (85%) and materials (15%) are key elements influencing the obtained results (117,000 Tm CO2e).

Efecto de distintos protocolos de irrigación en la resistencia a la fractura de dientes tratados endodónticamente / Effect of different irrigation protocols in the fracture resistance of endodontically treated teeth

Introducción: El objetivo del tratamiento endodóntico es la prevención y eliminación de una infección microbiana en el sistema de conductos radiculares gracias a la instrumentación, irrigación y obturación. Como pieza clave del tratamiento, la irrigación se tiene que enfrentar a diversos problemas siendo uno de ellos su posible efecto en la erosión dentinaria. Objetivo: Cuantificar la erosión dentinaria causada por distintas secuencias de irrigación, mediante la resistencia a la fractura. Material y métodos: Se seleccionaron 60 dientes unirradiculares que fueron instrumentados y montados en acrílico autopolimerizable, con espacio que simulaba el ligamento periodontal, y fueron divididos en dos grupos a los que se realizó un protocolo de irrigación con EDTA y NaClO (de 1 y 20 minutos respectivamente) y otro sin irrigación como control. Las muestras fueron posteriormente sometidas a una máquina de ensayos dinámicos de materiales que aplicó fuerza constante hasta fractura. Resultados: La media de la carga de rotura fue similar en los tres grupos, observándose ligeras diferencias del grupo 1 (NaClO 1 minuto) con el resto y mas variabilidad entre las muestras de dicho grupo. Conclusiones: En las condiciones de este estudio, la resistencia del diente no se ve afectada entre irrigar 1 minuto o 20 minutos de NaClO, después de eliminar el barrillo dentinario (AU)

The objectives: in endodontic therapy are prevention and the elimination of a microbial infection in the root canal system. This is done with instrumentation, irrigation and the adequate sealing of the root canals. A key factor in achieving a successful treatment is irrigation; nevertheless, irrigating has potential secondary detrimental effects, such as dentinal erosion. Objective: Quantifying the dentinal erosion in teeth caused by diverse irrigation protocols, and measuring its resistance to fracture. Material and Methods: A selection of 60 teeth with one canal was made. They were instrumented and placed in an acrylic base, and a simulation of the periodontal ligament was created. The teeth were divided in three groups. The first two, followed an irrigation protocol of EDTA and NaClO (1 or 20 minutes, depending on the group), and the third, a control group. The teeth were then subjected to pressure until fracture was achieved. Results: The average load in which the teeth were able to fracture was similar in the groups. However, there were slight differences between group 1 (NaClO, 1 minute), in comparison with the other groups. Conclusions: In this study, we determined that after removing the smear layer, there is no difference (1 or 20 minutes NaClO) in the resistance until fracture (AU)

A new proposal for greenhouse gas emissions responsibility allocation: best available technologies approach.

In recent years, several methodologies have been developed for the quantification of greenhouse gas (GHG) emissions. However, determining who is responsible for these emissions is also quite challenging. The most common approach is to assign emissions to the producer (based on the Kyoto Protocol), but proposals also exist for its allocation to the consumer (based on an ecological footprint perspective) and for a hybrid approach called shared responsibility. In this study, the existing proposals and standards regarding the allocation of GHG emissions responsibilities are analyzed, focusing on their main advantages and problems. A new model of shared responsibility that overcomes some of the existing problems is also proposed. This model is based on applying the best available technologies (BATs). This new approach allocates the responsibility between the producers and the final consumers based on the real capacity of each agent to reduce emissions. The proposed approach is demonstrated using a simple case study of a 4-step life cycle of ammonia nitrate (AN) fertilizer production. The proposed model has the characteristics that the standards and publications for assignment of GHG emissions responsibilities demand. This study presents a new way to assign responsibilities that pushes all the actors in the production chain, including consumers, to reduce pollution.