Material Stock Demographics: Cars in Great Britain.

Recent literature on material flow analysis has been focused on quantitative characterization of past material flows. Fewer analyses exist on past and prospective quantification of stocks of materials in-use. Some of these analyses explore the composition of products' stocks, but a focus on the characterization of material stocks and its relation with service delivery is often neglected. We propose the use of the methods of human demography to characterize material stocks, defined herein as stock demographics, exploring the insights that this approach could provide for the sustainable management of materials. We exemplify an application of stock demographics by characterizing the composition and service delivery of iron, steel, and aluminum stocks of cars in Great Britain, 2002-2012. The results show that in this period the stock has become heavier, it is traveling less, and it is idle for more time. The visualization of material stocks' dynamics demonstrates the pace of product replacement as a function of its usefulness and enables the formulation of policy interventions and the exploration of future trends.This work was supported by EPSRC, grant reference EP/N02351X/1.This is the final version of the article. It first appeared from the American Chemical Society via https://doi.org/10.1021/acs.est.5b0501

A new anode material for oxygen evolution in molten oxide electrolysis

Molten oxide electrolysis (MOE) is an electrometallurgical technique that enables the direct production of metal in the liquid state from oxide feedstock and compared with traditional methods of extractive metallurgy offers both a substantial simplification of the process and a significant reduction in energy consumption. MOE is also considered a promising route for mitigation of CO[subscript 2] emissions in steelmaking, production of metals free of carbon, and generation of oxygen for extra-terrestrial exploration. Until now, MOE has been demonstrated using anode materials that are consumable (graphite for use with ferro-alloys and titanium) or unaffordable for terrestrial applications (iridium for use with iron). To enable metal production without process carbon, MOE requires an anode material that resists depletion while sustaining oxygen evolution. The challenges for iron production are threefold. First, the process temperature is in excess of 1,538 degrees Celsius. Second, under anodic polarization most metals inevitably corrode in such conditions. Third, iron oxide undergoes spontaneous reduction on contact with most refractory metals and even carbon. Here we show that anodes comprising chromium-based alloys exhibit limited consumption during iron extraction and oxygen evolution by MOE. The anode stability is due to the formation of an electronically conductive solid solution of chromium(iii) and aluminium oxides in the corundum structure. These findings make practicable larger-scale evaluation of MOE for the production of steel, and potentially provide a key material component enabling mitigation of greenhouse-gas emissions while producing metal of superior metallurgical quality.American Iron and Steel Institut

Society and Materials: how it all started, a few million years ago

Materials have been closely related with History and Prehistory. Thus, Prehistory is divided into periods that are called by the name of the major material used at the time, such as the Ages of Stone and of Metals. Although materials are not considered any more as the major drivers that induced the changes from one age to another, they have been deeply entangled with the evolution of man-homo, of its ethnic groups and of the societies in which he lived. This article reviews the present knowledge about industries, cultures and ages as build by Prehistory as well as concepts of Paleoanthropology, in as far as they are needed to understand the main topic about materials. The analysis is based, initially, on the classic books of Leroi Gourhan, a French Prehistorian, Anthropologist and Philosopher, who helped Prehistory grow into its present scientific status: l’homme et la matière (Man and Matter), Milieu et technique (Context and Technology), Le geste et la parole (Technique et langage & la mémoire et les rythmes) (Gesture and speech)

Society and Materials: how it all started, a few million years ago

Materials have been closely related with History and Prehistory. Thus, Prehistory is divided into periods that are called by the name of the major material used at the time, such as the Ages of Stone and of Metals. Although materials are not considered any more as the major drivers that induced the changes from one age to another, they have been deeply entangled with the evolution of man-homo, of its ethnic groups and of the societies in which he lived. This article reviews the present knowledge about industries, cultures and ages as build by Prehistory as well as concepts of Paleoanthropology, in as far as they are needed to understand the main topic about materials. The analysis is based, initially, on the classic books of Leroi Gourhan, a French Prehistorian, Anthropologist and Philosopher, who helped Prehistory grow into its present scientific status: l’homme et la matière (Man and Matter), Milieu et technique (Context and Technology), Le geste et la parole (Technique et langage & la mémoire et les rythmes) (Gesture and speech)

À la mémoire de Jean-Sébastien Thomas (1968 - 2014)

Nous rendons hommage à Jean-Sébastien Thomas, éditeur invité de Matériaux & Techniques pour les numéros thématiques « Matériaux & Société », décédé le 3 décembre 2014 à l’âge de 46 ans